Patent Publication Number: US-9888221-B2

Title: Projector, projection display system, and corresponding method and recording medium

Description:
CONTINUITY DATA 
     This is a Division of application Ser. No. 14/144,993, filed Dec. 31, 2013, issued as U.S. Pat. No. 9,270,729 on Feb. 23, 2016, which is a Continuation application of Ser. No. 13/762,481, filed Feb. 8, 2013, issued as U.S. Pat. No. 8,654,109 on Feb. 18, 2014, which is a Continuation of application Ser. No. 13/067,068, filed May 5, 2011, now abandoned, which is a Continuation application of Ser. No. 12/805,092, filed Jul. 12, 2010, issued as U.S. Pat. No. 7,965,284 on Jun. 21, 2011, which is a Continuation of application Ser. No. 12/068,333, filed Feb. 5, 2008, issued as U.S. Pat. No. 7,782,330 on Aug. 24, 2010, which is a Continuation of application Ser. No. 10/048,055, filed Jan. 25, 2002, now U.S. Pat. No. 7,397,476, on Jul. 8, 2008, which in turn is a National Stage Application of PCT/JP01/04629, filed May 31, 2001. This application claims the benefit of Japanese Patent Application Nos. 2000-161876, filed May 31, 2000; 2000-175849, filed Jun. 12, 2000; and 2000-175868, filed Jun. 12, 2000. The disclosures of the prior applications are hereby incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a projection-type display apparatus or a projector connectable with a network, a method of displaying images via the network, and control of the operating conditions of the projector via the network. 
     BACKGROUND ART 
     The projector-type display apparatus or the projector is, for example, connected to an image generation apparatus, such as a personal computer, via a video cable and is used for presentations and other purposes. Analog RGB signals generated by the personal computer are input into the projector via the video cable and are projected as images on a screen or the like. 
     Under such working conditions, the personal computer simply exerts the function of outputting video signals to the projector. The work of connecting the personal computer with the projector via the video cable on every occasion of use is rather troublesome and time-consuming. 
     It is accordingly convenient to store data for the presentation in the projector. Under the recent development of the network environment, it is further convenient to distribute display video data to the projector via the network. In the structure of storing the presentation data in the projector, some protection policy is desired to prevent the stored data from being displayed by any third entity. 
     The projector for projecting and displaying images is capable of large screen display and is thus widely used in lectures, meetings, and school lessons. The projector is generally combined with a computer, which functions as an image supply apparatus to the projector and also as a control apparatus for controlling the working state of the projector, to constitute a display system. The computer as the control apparatus is conventionally connected with the projector via an interface like RS-232C and carries out various control operations to control the projector. 
     The user&#39;s control of the working state of the projector is implemented by execution of a specific software program by the computer. Otherwise the working state of the projector may be controlled with a remote control attached to the projector. 
     When there is a requirement to change the working state of the projector in the middle of a meeting, for example, an operator who operates the control apparatus generally carries out the change. When one of multiple participants, for example, in the meeting desires to change the working state of the projector, the participant should request the operator to change the working state of the projector. 
     In the case of changing the working state of the projector according to this procedure, there is a possibility that the request of change is not smoothly transferred from the participant to the operator. If the participant desires to directly operate the control apparatus, the participant should move to the position where the control apparatus is located. Because of these factors, the display system utilizing the prior art projector has poor operatability. 
     The user operates a remote control RM and causes a projector PJZ to carry out diverse processing as shown in  FIG. 30 . The projector PJZ projects and displays an image on a screen SC, in response to an analog video signal AV 1  supplied from an image supply apparatus  1900 . The user operates, for example, the remote control RM to superimpose an ornamental image like a pointer image PPJ on an original image ORG projected and displayed on the screen SC. Such superimposition of the ornamental image on the original image ORG enhances the effects of the presentation. 
     There are, however, difficulties in causing the projector PJZ to execute the processing with regard to the contents of the projected and displayed image through the operation of the remote control RM. This is ascribed to the rather poor operatability of the remote control RM. In the case of sequential presentations by a plurality of people with one projector, it is required to successively transfer the remote control RM among the respective presenters. This prevents smooth progress of the sequential presentations. 
     DISCLOSURE OF THE INVENTION 
     The object of the present invention is thus to solve the above drawbacks and actualize the above requirements and to allow storage of data in a projector while keeping secrecy of the data. The object of the invention is also to project and display the stored data while keeping secrecy of the data. 
     In order to attain at least part of the above objects, a first application of the present invention is an image display system, in which a computer and an image display apparatus including a storage device are connected with each other via a network. In the image display system according to the first application of the present invention, the computer includes: an input unit that is used to input at least one of data and a command; a data storage module that stores therein display data to be displayed by the image display apparatus; a password setting requirement module that requires setting of a password in the process of transferring desired data from the data storage module to the storage device of the image display apparatus; and a data transfer module that, when a password is set via the input unit, maps the preset password to the desired data and transfers the desired data with the password to the storage device of the image display apparatus. The image display apparatus includes: a data receiving module that stores the transferred desired data with the password into the storage device; an input unit that is used to input at least one of data and a command; an authentication module that, in response to selection of desired display data among data stored in the storage device, requires input of a password via the input unit and determines whether or not the input password is coincident with the preset password; and a projection display module that allows the selected display data to be projected and displayed when it is determined that the two passwords are coincident with each other. 
     In the image display system according to the first application of the present invention, setting of a password is required in the process of transferring data from the computer to the storage device of the image display apparatus. Data mapped to the preset password is then transferred to the storage device of the image display apparatus. In the image display apparatus, in response to selection of display data among plural data stored in the storage device, the technique requires input of a password and enables display data to be projected and displayed when the input password is coincident with the preset password. This arrangement desirably ensures secrecy of data stored in the storage device of the image display apparatus. This arrangement enables display of data while keeping secrecy of data, when the displayed data is stored in the storage device of the image display apparatus. 
     In the image display system according to the first application of the present invention, the data transfer module of the computer may transfer only the desired data to the storage device of the image display apparatus, when no password is set via the input unit. This arrangement allows transfer of data without setting a password. The projection display module of the image display apparatus may project and display a projection display forbid window representing failed authentication, when it is determined that the two passwords are not coincident with each other. This arrangement informs the user of a wrong input or a wrong selection. 
     In accordance with one preferable embodiment of the image display system according to the first application of the present invention, the computer further has a display screen, on which a list of data stored in the data storage module and an icon representing the image display apparatus are displayed, and the password setting requirement module requires setting of a password, when the desired data selected out of the list of storage data is dragged and dropped onto the icon of the image display apparatus on the display screen. This arrangement enables the transfer of data from the computer to the storage device of the image display apparatus to be visually observed, thus facilitating the operation. 
     The image display system according to the first application of the present invention may further include a file server connecting with the network. When a password is set via the input unit, the data transfer module of the computer maps the preset password to the desired data and transfers the desired data with the password to the file server. This arrangement assures storage of a large mass of data, which can not be stored in the storage device of the image display apparatus. 
     A second application of the present invention is a method of storing data to be displayed with a projector via a computer. The method includes the steps of: specifying data to be displayed; determining whether or not a requirement of storing the specified data into a storage device is output; when it is determined that the storing requirement is output, requiring setting of a password; mapping the preset password to the specified data; and transferring the data with the password to the storage device. 
     The data storage method according to the second application of the present invention requires setting of a password and transfers data with the preset password mapped thereto to the storage device for storage. This arrangement ensures secrecy of data stored in the storage device. 
     In one preferable embodiment of the data storage method according to the second application of the present invention, it is determined that the requirement of storing the specified data into the storage device is output, when an icon representing the specified data is dragged and dropped onto an icon representing the storage device on a display screen of the computer. This arrangement maps a general drag and drop operation of a data icon onto an icon of the storage device on the display screen to the requirement of setting a password, thus urging the user to set a password without any specific operation. 
     In the data storage method according to the second application of the present invention, the storage device may be incorporated in the projector or may be incorporated in a file server, which is connected with the projector and the computer via a network. The incorporation of the storage device in the projection display apparatus enables stored data to be displayed by the projection display apparatus alone. The incorporation of the storage device in the file server ensures storage of a large mass of data. 
     A third application of the present invention is a method of causing display data including display data mapped to a password with an image display apparatus. The method includes the steps of: specifying desired display data to be displayed, among a plurality of display data; determining whether or not the specified display data is mapped to a password; when it is determined that the specified display data is mapped to a password, requiring input of a password, which is expected to be assigned to the specified display data; determining whether or not the input password is coincident with the password mapped to the specified display data; and allowing the display data to be displayed, when it is determined that the input password is coincident with the password mapped to the specified display data. 
     In the third application of the present invention, the method requires input of a password in response to a display requirement of display data mapped to a password and enables the display data to be displayed when the input password is coincident with the mapped password. Namely the image display apparatus does not allow the display of the display data unless the input password is coincident with the mapped password. This arrangement desirably ensures secrecy of display data. 
     The method according to the third application of the present invention may further include the step of showing prohibition of display of the display data, when it is determined the input password is not coincident with the password mapped to the specified display data. This arrangement informs the user of a wrong input or wrong selection. 
     A fourth application of the present invention is an image display apparatus having a function of data protection. The image display apparatus according to the fourth application of the present invention includes: an input unit that is used to input at least one of data and a command; a display data storage module that stores display data including display data mapped to a password; a password requirement module that requires input of a password, in response to a display requirement for displaying the display data mapped to the password; an authentication module that determines whether or not a password input via the input unit is coincident with the password mapped to the display data; and a projection display module that allows the required display data to be projected and displayed, when it is determined that the two passwords are coincident with each other. 
     In the fourth application of the present invention, the technique requires input of a password in response to a display requirement of display data that is mapped to a password and stored in the display data storage module and enables the display data to be projected and displayed when the input password is coincident with the mapped password. Namely the image display apparatus does not allow the projection and display of the display data unless the input password is coincident with the mapped password. This arrangement desirably ensures secrecy of display data stored in the display data storage module of the image display apparatus. 
     A fifth application of the present invention is an image display apparatus having a storage device in which display data is stored. The image display apparatus according to the fifth application of the present invention includes: an input unit that is used to input at least one of data and a command; a data list display module that displays a list of data stored in the storage device; a password input window display module that, in response to selection of data out of the data list, displays an input window of a password assigned to the selected data; an authentication module that determines whether or not the password input via the input unit is coincident with a preset password mapped to the selected data; and a projection display module that allows the selected data to be projected and displayed, when it is determined that the input password is coincident with the preset password. 
     In the fifth application of the present invention, the technique displays a password input window in response to selection of desired data out of a list of data and enables the selected data to be projected and displayed when the input password is coincident with a preset password. Namely the image display apparatus does not allow the projection and display of the selected data unless the input password is coincident with the preset password. This arrangement desirably ensures secrecy of data stored in the storage device of the image display apparatus. 
     The image display apparatus according to the fifth application of the present invention may further include a forbid window display module that displays a projection display forbid window representing failed authentication, when the input password is not coincident with the preset password. 
     A sixth application of the present invention is a computer readable medium, in which a program executed on a computer for storing data to be displayed with a projector is stored. The program causes the computer to attain the functions of: specifying data to be displayed; determining whether or not a requirement of storing the specified data into a storage device is output; when it is determined that the storing requirement is output, requiring setting of a password; mapping the preset password to the specified data; and transferring the data with the password to the storage device. 
     The technique according to the sixth application of the present invention requires setting of a password in the process of storing data in the storage device and transfers and stores the data mapped to the preset password to and in the storage device. This arrangement desirably keeps the secrecy of data stored in the storage device. 
     A seventh application of the present invention is a computer readable medium, in which a program for allowing display data mapped to a password to be displayed on an image display apparatus. The program causes the computer to attain the functions of: specifying desired display data to be displayed, among a plurality of display data; determining whether or not the specified display data is mapped to a password; when it is determined that the specified display data is mapped to a password, requiring input of a password, which is expected to be assigned to the specified display data; determining whether or not the input password is coincident with the password mapped to the specified display data; and allowing the display data to be displayed, when it is determined that the input password is coincident with the password mapped to the specified display data. 
     In the seventh application of the present invention, a password is assigned to the specified display data among multiple display data. The method requires input of a password and displays the specified display data when the input password is coincident with the assigned password. Each of the plural display data is protected by the assigned password. The display data is not displayed unless the input password is coincident with the assigned password. 
     The object of the present invention is also to solve the drawbacks of the prior art technique discussed above and to enhance the operatability of controlling the working state of a projector. 
     In order to attain at least part of the above object, an eighth application of the present invention is a projector connectable with a network. The projector according to the eighth application of the present invention includes: a projection display module that causes an image to be projected and displayed; and a Web server module that is capable of distributing Web page information, which includes working status information representing a working status of the projection display module. The Web server module has: a page information distribution module that distributes the Web page information, which includes the working status information representing the working status of the projection display module, to a Web client in response to a requirement from the Web client; a control signal supply module that supplies a control signal for controlling the working status of the projection display module to the projection display module, according to control information input on a Web page distributed to and displayed on the Web client and sent back; and a page information update module that fetches new working status information representing a new working status of the projection display module controlled by the control signal and updates the Web page information distributed to the Web client. 
     In the projector according to the eighth application of the present invention, the working state of the projection display module is controlled according to the control information input on the Web page distributed to the Web client (also referred to as the Web browser). This arrangement ensures easy control of the working state of the projector via the network and thus enhances the operatability of controlling the working state of the projector, compared with the prior art technique. 
     Here it is preferable that the Web page includes a button operated to change the working status of the projector, and a press of the button causes the control information to be transmitted to the projector. 
     The user can readily change the working state of the projector by simply clicking the button on the Web page displayed on the Web client. 
     The eighth application of the present invention may be actualized by diverse embodiments, for example, a method of controlling the working state of the projector, a computer program to attain the method or the functions of a corresponding apparatus, a recording medium in which such a computer program is recorded, and a data signal that includes such a computer program and is embodied in a carrier wave. 
     The object of the present invention is also to solve the drawbacks of the prior art technique discussed above and to provide a technique in which the user enables a projector to readily execute a series of processing with regard to the contents of a projected and displayed image. 
     In order to attain at least part of the above object, a ninth application of the present invention is a projector connecting with an external input apparatus having an input unit via a network. The projector according to the ninth application of the present invention includes: a network interface module that connects with the network; a video data generation module that executes a predetermined series of processing with regard to contents of an image to be projected and displayed and generates video data representing the image to be projected and displayed, based on operation information generated through an operation of the input unit of the eternal input device and supplied to the network interface module via the network; an electro-optic device that generates an image ray according to the video data; and a projection optical system that projects the image ray generated by the electro-optic device. 
     In the projector according to the ninth application of the present invention, the series of processing with regard to the contents of the projected and displayed image is carried out to generate the video data, based on the operation information supplied via the network interface module. The user accordingly enables the projector to readily execute the series of processing with regard to the contents of the projected and displayed image by a simple operation of the input unit incorporated in the external input apparatus. 
     Connection of multiple external input apparatuses to the network ensures the smooth progress of sequential presentations, which are made by a plurality of people with one projector. 
     In one preferable embodiment of the projector according to the ninth application of the present invention, the image to be projected and displayed includes an original image and an ornamental image superimposed on the original image, ornamental video data representing the ornamental image is not supplied from the external input apparatus but is prepared by the video data generation module, and the video data generation module combines original video data representing the original image with the ornamental video data to generate the video data, based on the operation information supplied from the external storage device, thereby superimposing the ornamental image at a predetermined position on the original image. 
     The user operates the input unit incorporated in the external input apparatus to superimpose the ornamental image on the projected and displayed original image. 
     In the projector according to the ninth application of the present invention, it is preferable that the operation information includes at least positional information, which is generated through an operation of a pointing device used as the input unit of the external input apparatus, and the video data generation module superimposes a pointer image as the ornamental image at the predetermined position on the original image, based on the positional information. 
     In this arrangement, the user can readily move the pointer image superimposed on the projected and displayed original image by a simple movement of the pointing device incorporated in the external input apparatus. 
     In the projector according to the ninth application of the present invention, it is also preferable that the positional information includes coordinate value information specified by the pointing device. 
     This arrangement enables the position specified by the pointing device to be readily mapped to the position of the pointer image superimposed on the projected and displayed original image. 
     In one preferable embodiment of the projector according to the ninth application of the present invention, the operation information further includes switch information generated through an operation of a switch mounted on the pointing device, and the video data generation module superimposes an ornamental image, which is different from the pointer image, in a specified area on the original image, based on the positional information and the switch information included in the operation information. 
     The operation information including the positional information and the switch information can specify the specific area in the original image. This allows an ornamental image, which is different from the pointer image, to be superimposed in the specified area. 
     In another preferable embodiment of the projector according to the ninth application of the present invention, the operation information further includes key information generated through an operation of a keyboard as the input device of the external input apparatus, and the video data generation module superimposes a symbol image as the ornamental image on the original image, based on the key information. 
     In this arrangement, a symbol image like letters is readily superimposed on the projected and displayed original image by a simple user&#39;s operation of the keyboard incorporated in the external input apparatus. 
     A tenth application of the present invention is a projection display system including an external input apparatus and a projector connecting with each other via a network. In the projection display system according to the tenth application of the present invention, the external input apparatus includes: an input unit; an operation information generation module that detects a user&#39;s operation of the input unit and generates operation information based on a result of the detection; and a first network interface module that connects with the network and supplies the operation information to the projector via the network. The projector includes: a second network interface module that connects with the network; a video data generation module that executes a predetermined series of processing with regard to contents of an image to be projected and displayed and generates video data representing the image to be projected and displayed, based on the operation information supplied to the second network interface module via the network; an electro-optic device that generates an image ray according to the video data; and a projection optical system that projects the image ray generated by the electro-optic device. 
     The projection display system according to the tenth application of the present invention includes the projector according to the ninth application of the present invention and thus exerts the similar functions and effects to those of the projector. The user enables the projector to readily carry out a series of processing with regard to the contents of a projected and displayed original image by a simple operation of the input unit incorporated in the external input apparatus. 
     In one preferable embodiment of the projection display system according to the tenth application of the present invention, the external input apparatus further has a display unit, and the operation information generation module causes an operation information generation area, in which the operation information is generated in response to the operation of the pointing device, to be displayed on the display unit, and detects the operation of the pointing device only when a pointer image corresponding to the pointing device is present in the operation information generation area. 
     In this arrangement, the operation information is generated only when the pointer image is present in the operation information generation area. While the pointer image is located out of the operation information generation area, the user can implement another operation with the pointing device. 
     In the projection display system according to the tenth application of the present invention, it is preferable that the operation information generation area is mapped to an image area to be projected and displayed. 
     This arrangement enables the positional relation of the pointer image in the operation information generation area to be substantially coincident with the positional relation of the pointer image in the projected and displayed image area. 
     An eleventh application of the present invention is a method of generating operation information that is generated through an operation of an input unit included in an external input apparatus and is supplied to a projector, which is connected to the external input apparatus via a network. The method includes the steps of: (a) detecting a user&#39;s operation of the input unit; and (b) generating the operation information, based on a result of the detection. 
     In this arrangement, the user operates the input unit included in the external input apparatus to generate the operation information. Supply of the operation information to the projector enables the projector to readily execute a predetermined series of processing with regard to the contents of a projected and displayed image. 
     In one preferable embodiment of the method according to the eleventh application of the present invention, the step (a) includes the steps of: (a-1) causing an operation information generation area, in which the operation information is generated in response to an operation of a pointing device as the input unit, to be displayed on a display unit incorporated in the external input apparatus; and (a-2) detecting the operation of the pointing device only when a pointer image corresponding to the pointing device is present in the operation information generation area. 
     In this arrangement, the operation information is generated only when the pointer image is present in the operation information generation area. While the pointer image is located out of the operation information generation area, the user can perform another operation with the pointing device. 
     A twelfth application of the present invention is a computer readable recording medium in which a computer program is recorded, where the computer program generates operation information that is generated through an operation of an input unit incorporated in an external input apparatus and is supplied to a projector, which is connected to the external input apparatus via a network. The computer program causes a computer to attain the functions of: detecting a user&#39;s operation of the input unit; and generating the operation information, based on a result of the detection. 
     Like the method of the present invention discussed above, when the external input apparatus executes the computer program recorded in the recording medium, the user can generate the operation information through an operation of the input unit incorporated in the external input apparatus. Supply of the operation information to the projector enables the projector to readily execute a predetermined series of processing with regard to the contents of a projected and displayed image. 
     The ninth through the twelfth applications of the present invention may be actualized by diverse embodiments, for example, computer programs to attain the functions of the projector or the projection display system, recording media in which such computer programs are recorded, and data signals that include such computer programs and are embodied in carrier waves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the configuration of an image display system constructed through connection of a projector with a network in a first embodiment; 
         FIG. 2  is a block diagram showing the internal circuit structure of the projector in the first embodiment; 
         FIG. 3  is a flowchart showing a processing routine executed to transfer display data from a personal computer PC to the projector  10 ; 
         FIG. 4  shows a series of processing carried out on a display  54  of the personal computer PC to transfer the display data from the personal computer PC to the projector  10 ; 
         FIG. 5  shows an example of a password setting window open on the display  54  after conclusion of the processing shown in  FIG. 4 ; 
         FIG. 6  is a flowchart showing a processing routine executed when the projector  10  reproduces a data file stored in an external storage device  41 ; 
         FIG. 7  schematically illustrates a remote control  40  used in the first embodiment; 
         FIG. 8  shows an example of a menu window open on a projection display screen SR of the projector  10 ; 
         FIG. 9  shows an example of a file selection window open on the projection display screen SR of the projector  10 ; 
         FIG. 10  shows an exemplified display of a password input box PB 1  open on the projection display screen SR of the projector  10 ; 
         FIG. 11  shows an exemplified display of a failed authentication display box PB 2  open on the projection display screen SR of the projector  10 ; 
         FIG. 12  shows an exemplified display of a reproduction forbid display box PB 3  open on the projection display screen SR of the projector  10 ; 
         FIG. 13  illustrates a layout of another projector in a second embodiment of the present invention; 
         FIG. 14  is a functional block diagram illustrating the construction of an ASP terminal module  20  functioning as a Web server module; 
         FIG. 15  shows a homepage distributed from the Web server module  20  and displayed on a Web browser CC; 
         FIG. 16  shows a working state setting menu window open on the Web browser CC as a Web page; 
         FIG. 17  shows a video setting window open on the Web browser CC as a Web page; 
         FIG. 18  shows an audio setting window open on the Web browser CC as a Web page; 
         FIG. 19  shows the video setting window after an increase in brightness by one step; 
         FIG. 20  illustrates a projection display system in a third embodiment of the present invention; 
         FIG. 21  schematically illustrates the structure of a projector PJ 1  shown in  FIG. 20 ; 
         FIG. 22  schematically illustrates the structure of a computer PC 1  shown in  FIG. 20 ; 
         FIG. 23  shows one application of the projection display system of  FIG. 20 ; 
         FIG. 24  is a flowchart showing series of processing executed by the projector PJ 1  and the computer PC 1 ; 
         FIG. 25  shows an Operation Detection window DW open on a display unit  1350  of the computer PC 1 ; 
         FIGS. 26A-26F  show a process of superimposing a box image PB on an original image ORG by utilizing a pointer image PPJ in the original image ORG; 
         FIG. 27  shows an image projected and displayed in response to a user&#39;s operation of a keyboard KB as an input unit  1360 ; 
         FIG. 28  shows a projection display system in a fourth embodiment; 
         FIG. 29A-29C  show a series of processing to directly edit the contents of an original image ORG projected and displayed on a screen SC; and 
         FIG. 30  shows a prior art projector. 
     
    
    
     BEST MODES OF CARRYING OUT THE INVENTION 
     First Embodiment 
     A projector having security functions and an image display system constructed through connection of the projector with a network are discussed below as a first embodiment of the present invention with reference to the drawings. 
     A. Construction of Projector in First Embodiment 
     The following describes the schematic structure of a projection-type display apparatus or a projector in the first embodiment with referring to  FIGS. 1 and 2 .  FIG. 1  shows the configuration of an image display system constructed through connection of the projector with a network in the first embodiment.  FIG. 2  is a block diagram showing the internal circuit structure of the projector in the first embodiment. 
     A projector  10  is connected to a file server FS and a personal computer (computer) PC via a network line NL. The personal computer PC includes a CPU  50  that executes application programs, a ROM  51  that stores therein the application programs, and a RAM  52  that temporarily registers the contents of processing under execution of the application programs. The personal computer PC also has an internal hard disk drive (HDD)  53  that stores therein data (display data, files) generated by the application programs after conclusion of the application programs and a display  54  that displays user interfaces of the application programs. The display data stored in the HDD  53  of the personal computer PC are transferred to either the projector  10  or the file server FS according to a procedure discussed later. Commands and data are input into the personal computer PC through an external wireless input device  55  like a keyboard  551  and a mouse  552 . 
     The projector  10  has an external storage device  41 , for example, a memory card in conformity to the PCMCIA standard, in which the display data transferred from the personal computer PC are stored. Commands and data are input into the projector  10  through an external input device  40  like a remote control. The file server FS functions to store the display data in place of the projector  10 . For reproduction (projection)) of display data, when the projector  10  requires the file server FS to transfer the display data, the required display data are transferred from the file server FS to the projector  10  via the network line NL. 
     The internal structure of the projector  10  of the first embodiment is discussed with reference to  FIG. 2 . The projector  10  has an ASP terminal module  20  mainly exerting functions of an ASP terminal and a projector module  30  mainly exerting conventional projector functions. The projector  10  of the first embodiment accordingly functions as an ASP terminal. 
     The ASP terminal module  20  includes a first central processing unit (CPU)  200  that executes viewer applications, ASP client applications, and other diverse operations, a first read only memory (ROM)  202  that stores therein a variety of programs including the viewer applications and the client applications executed by the first CPU  200 , and a first random access memory (RAM)  204  that temporarily registers therein the results of the operations by the first CPU  200  and data. An authentication program, which is executed before reproduction (projection display) of display data, is also stored in the first ROM  202 . The first CPU  200  and the first ROM  202  are connected with each other to allow one-way or two-way communication. The first CPU  200  and the first RAM  204  are connected with each other to allow two-way communication. 
     The ASP terminal module  20  has a graphics controller  210 , which is connected with the first CPU  200  to allow two-way communication and generates video data in response to a drawing instruction output from the first CPU  200 . The graphics controller  210  has an LSI chip (not shown) for generating images and a video memory or a first frame memory (VRAM)  212  for storing the generated images (display images) therein. 
     The ASP terminal module  20  is provided with a network interface controller  220 , an I/O port  230 , a PCMCIA interface controller  240 , and a USB controller  250 , which function as interfaces used for transmission of commands and data between the projector  10  and external devices. The network interface controller  220  is, for example, in conformity to the Ethernet standard and converts the commands and data to be transmitted from the ASP terminal module  20  to the network line NL into an adequate format according to a protocol of network communication, while converting the signals received from the network line NL into a format suitable for the processing executed in the ASP terminal module  20 . The I/O port is a general input-output port and is connected with a wireless input unit  234  via an identification circuit  232  and with the external input device  40  and a second CPU  300  in the projector module  30 . The wireless input unit  234  receives input data wirelessly transmitted from a wireless input device. The identification unit  232  identifies the input data received by the wireless input unit  234  as input data addressed to the ASP terminal module  20 . 
     The PCMCIA interface controller  240  transfers data from the ASP terminal module  20  to an external device and inversely from the external device to the ASP terminal module  20  according to the PCMCIA standard. In this embodiment, for example, a PC memory card is connected as the external storage device  41 , and the display data transferred from the personal computer PC are stored in the external storage device  41 . The USB controller  250  takes charge of transmission of data between the ASP terminal module  20  and the external device according to the USB standard, and is connected with the external input device  40 , for example, via a USBHUB  252 . 
     The ASP terminal module  20  is further connected with a real time clock  260  that supplies the absolute time in the ASP terminal module  20  and with a sound source  262  that generates audio data in response to an instruction output from the first CPU  200 . 
     The first CPU  200  and the respective controllers like  210  are mutually connected via a bus for transmitting data and commands in the ASP terminal module  20 . 
     The structure of the projector module  30  is discussed below. The projector module  30  includes a second central processing unit (CPU)  300  that executes predetermined programs to control respective circuits in the projector module  30 , a second read only memory (ROM)  302  that stores therein the programs executed by the second CPU  300 , and a second random access memory (RAM)  304  that temporarily registers therein the results of operations by the second CPU  300  and data. The second CPU  300  and the second ROM  302  are connected with each other to allow one-way or two-way communication. The second CPU  300  and the second RAM  304  are connected with each other to allow two-way communication. The second CPU  300  and the first CPU  200  are communicated with each other via the UP port  230  to allow two-way communication, so that data and commands are transmittable between the first CPU  200  and the second CPU  300 . 
     The projector module  30  is further provided with a video signal conversion circuit  310 , an audio control circuit  320 , a liquid crystal (LCD) driving circuit  330 , a light source driving circuit  340 , a cooling fan control circuit  350 , and a projection optical system  360 . 
     The video signal conversion circuit  310  exerts analog-to-digital conversion, decoding, synchronizing signal separation, and image processing functions. More concretely, the video signal conversion circuit  310  converts analog video signals input from an external video signal input terminal  312  into digital video data, and writes the converted digital video data into a non-illustrated frame memory included in the video signal conversion circuit  310  or reads the digital video data, which has been written previously into the frame memory, from the frame memory in synchronism with a synchronizing signal. Typical examples of the input analog video signals include RGB signals output from the personal computer and composite video signals output from a video cassette recorder. In the case where the input analog video signal is a composite video signal, the video signal conversion circuit  310  demodulates the composite video signal, separates a component video signal consisting of three color signal components RGB from a synchronizing signal included in the composite video signal, and converts the component video signal into digital video data. In the case where the input analog video signal is an RGB signal output from the personal computer, on the other hand, the synchronizing signal separation is not required since the RGB signal is input as a component video signal separately from the synchronizing signal. The video signal conversion circuit  310  thus simply converts the component video signal into digital video data. 
     The video signal conversion circuit  310  also receives digital video signals transmitted from the graphics controller  210  in the ASP terminal module  20 . Neither the analog-to-digital conversion nor the synchronizing signal separation is required since the digital video signal is input separately from the synchronizing signal. 
     The audio control circuit  320  is connected with an external audio signal input terminal  322 , a speaker  324 , the second CPU  300 , and the sound source  262  in the ASP terminal module  20 . The audio control circuit  320  connecting with the second CPU  300  drives the speaker  324  with a driving signal, which is generated based on an audio signal or sound data transferred from the external audio signal input terminal  322  or the sound source  262 , in response to an instruction output from the second CPU  300 . 
     The LCD driving circuit  330  receives video data processed by the video signal conversion circuit  310  and drives an LCD  332  according to the input video data to modulate light emitted from a light source  342 . The light modulated by the LCD  332  is projected on a projection plane, for example, on a projection screen, via the projection optical system  360  including lenses. The light source  342  is connected with the light source control circuit  340 , which controls on and off the light source  342  in response to an instruction output from the second CPU  300 . A cooling fan  352  is disposed behind the light source  342  to blast the cooling air against the light source  342 . The cooling fan  352  is connected with the cooling fan control circuit  350 , which regulates the revolving speed of the cooling fan  352  in response to an instruction output from the second CPU  300 . 
     It is desirable that the ASP terminal module  20  is mounted, for example, on one printed wiring board to allow arbitrary attachment to and detachment from the projector. As clearly understood from the structure of  FIG. 2 , this projector is capable of projecting and displaying images in response to externally supplied video signals even in the non-attachment state of the ASP terminal module  20 . The arbitrary attachment and detachment of the ASP terminal module  20  to and from the projector facilitates construction of both a projector with the functions of the ASP terminal module  20  (that is, the ASP terminal functions and drawing functions discussed later) and a projector without the functions of the ASP terminal module  20 . 
     B. Basic Operations of Projector in First Embodiment 
     The following describes the basic operations of the projector  10  having the above construction with reference to  FIGS. 1 and 2 . 
     A signal input into the projector  10  via the network line NL is converted into a specific format suitable for the ASP terminal module  20  by the network interface controller  220  of the ASP terminal module  20 , and is transferred as data and a command to the first CPU  200 . The first CPU  200  temporarily registers the transferred data into the first RAM  204  and determines whether the transferred command is a command addressed to the ASP terminal module  20  or a command addressed to the projector module  30 . When the transferred command is a command addressed to the projector module  30 , the first CPU  200  further transfers the command to the second CPU  300  in the projector module  30  via the I/O port  230 . 
     When the transferred command is a command addressed to the ASP terminal module  20 , on the other hand, the first CPU  200  carries out an operation based on the transferred command. For example, the first CPU  200  stores the data, which has temporarily been registered in the first RAM  204 , into the external storage device  41 . In another example, the first CPU  200  carries out an authentication program, which will be discussed later, in response to a requirement of reproducing (a requirement of projecting and displaying) the data stored in the external storage device  41 , which is input through the remote control  40 . In order to read (reproduce) the data stored in either the external storage device  41  or the first RAM  204 , the first CPU  200  reads and activates an adequate viewer application from the first ROM  202  to generate user interface data of the stored data and transfers the user interface data together with a drawing command to the graphics controller  210 . 
     In still another example, when the projector  10  functions as a client of server base computing (SBC), the first CPU  200  activates a corresponding client application and transmits a drawing command to the graphics controller  210  to generate user interface video data from input display video data having a specific format. The graphics controller  210  generates the user interface video data (hereinafter simply referred to as the ‘video data’) to be displayed based on the user interface data or the display video data in response to the input drawing command, and stores the generated video data into the VRAM  212  included in the graphics controller  210 . 
     In response to an instruction output from the first CPU  200 , the graphics controller  210  reads the video data from the VRAM  212  of the graphics controller  210  at a preset timing and transfers the video data to the video signal conversion circuit  310  of the projector module  30 . The first CPU  200  receives a command or data from the external input device  40  via the USBHUB  252 , the USB controller  250 , and the I/O port  230 . The first CPU  200  may write the data stored in the first RAM  204  or the video data stored in the VRAM  212  of the graphics controller  210  via the PCMCIA interface controller  240  into the external storage device  41 , in response to a command input from the external input device  40  or via the network line NL. 
     When receiving video data from the graphics controller  210 , the video signal conversion circuit  310  carries out the series of processing discussed above and transfers the processed video data to the LCD driving circuit  330 . The LCD driving circuit  330  drives and controls the LCD  332  based on the input video data, and causes desired video data to be projected on the projection screen. 
     When the command transferred from the network line NL via the I/O port  230  represents an ON instruction of the light source  342 , the second CPU  300  turns the light source  342  ON via the light source control circuit  340 . The second CPU  300  regulates the working conditions (for example, the rotational speed and the rotational timing) of the cooling fan  352  according to the temperature of the light source  342  via the cooling fan control circuit  350 . 
     The data transmission from the projector  10  to the network line NL is carried out via the network interface controller  220 , in response to an instruction output from the first CPU  200 . 
     C. Process of Storing Display Data into Projector and Process of Displaying Display Data with Projector in First Embodiment 
     The following describes a series of processing executed to transfer display data (file) from the personal computer PC to the projector  10  of the above construction via the network with referring to  FIGS. 1 and 3 to 5 .  FIG. 3  is a flowchart showing a processing routine executed to transfer the display data from the personal computer PC to the projector  10 .  FIG. 4  shows a series of processing carried out on the display  54  of the personal computer PC to transfer the display data from the personal computer PC to the projector  10 .  FIG. 5  shows an example of a password setting window open on the display  54  after conclusion of the processing shown in  FIG. 4 . 
     Data like presentation data and word processor data generated by execution of an application program on the personal computer PC are temporarily registered in the RAM  52  of the personal computer PC during execution of the application program. On conclusion of the application program, the data are stored in the form of a data file in the internal HDD  53  of the personal computer PC. Multiple data files including those generated in the past are accordingly stored in the HDD  53 . 
     In the processing routine shown in  FIG. 3 , the CPU  50  of the personal computer PC waits for input of a file storage requirement (step S 100 : No). When detecting input of a file storage requirement (step S 100 : Yes), the CPU  50  requires input of a destination of file storage (step S 110 ). 
     General operating systems use a graphical user interface (GUI) shown on the display  54  to visually execute a diversity of operations. In such a GUI environment, as shown in  FIG. 4 , a file icon FL assigned to each file stored in the HDD  53  is shown in a window FW on the display  54 , and a projector icon PJ representing the projector  10  as the destination of transfer is shown on the display  54 . In order to move (transfer) a file from the HDD  53  to the projector  10 , the process places a mouse pointer MP on a desired file icon FL, moves the mouse pointer MP onto the projector icon PJ during a press of a selection button of the mouse  552 , and releases the selection button on the projector ion PJ. This series of actions is a file movement operation known as drag and drop (D&amp;D). 
     When the coordinate position of the mouse pointer MP overlaps the area of the projector icon PJ during a press of the selection button of the mouse  552  and the selection button of the mouse  552  is then released in the area, the CPU  50  of the personal computer PC detects input of the file storage requirement. 
     The CPU  50  of the personal computer PC determines whether or not the input destination of file storage is a default (step S 120 ). When the destination of file storage is the default (step S 120 : Yes), a password input window PW is open on the display  54  (step S 130 ) to ask for setting a password as shown in  FIG. 5 . In this embodiment, the destination of file storage set as the default is the external storage device  41  of the projector  10 . The default is changeable to an arbitrary destination of file storage through the operations on the setting window in this processing routine. 
     When the input destination of file storage is different from the default (step S 120 : No), on the other hand, the CPU  50  of the personal computer PC changes the destination of file storage (step S 140 ) and requires setting of a password (step S 130 ). In this embodiment, desired files may be stored in, for example, the file server FS connecting with the personal computer PC via the network line NL. The storage capacity of the external storage device  41  of the projector  10  is generally not so large. The file server FS is thus conveniently used to store a large quantity of files (data). 
     The CPU  50  of the personal computer PC determines whether or not a password has been set (step S 150 ). When a password has been set (step S 150 : Yes), the password is mapped to the dragged and dropped file (step S 160 ). The CPU  50  transfers the file mapped to the password to the preset destination of file storage (step S 170 ) and exits from this processing routine. The transferred file is stored in either the external storage device  41  of the projector or the file server FS. 
     In the process of setting a password, for example, when five arbitrary numerals 1 to 5 are input via the keyboard  551 , five asterisks are shown in an input box PW 1  of the password input window PW. The user re-enters the same password in a confirmation input box PW 2  for the purpose of confirmation and clicks an ‘OK’ button with the mouse pointer MP to set the password. When input of the password is not required, the user clicks the ‘OK’ button with the mouse pointer MP with the input box PW 1  left blank to close the password input window PW. In this embodiment, the available numerals input from the remote control  40  are 1 to 5 as discussed later, so that the numerals used for setting the password are limited to the range of 1 to 5. Other numerals and letters may be combined according to the specification of the remote control. 
     When no password has been set (step S 150 : No), on the other hand, the CPU  50  of the personal computer PC transfers only the file to the preset destination of file storage (step S 170 ) and exits from this processing routine. The transferred file is stored in either the external storage device  41  of the projector or the file server FS. 
     The following describes a series of authentication process executed when the projector  10  reproduces the display data stored in the external storage device  41 , with referring to  FIGS. 1, 2, and 6 to 12 .  FIG. 6  is a flowchart showing a processing routine executed when the projector  10  reproduces the data file (display data) stored in the external storage device  41 .  FIG. 7  schematically illustrates the remote control  40  used in this embodiment.  FIG. 8  shows an example of a menu window open on a projection display screen SR of the projector  10 .  FIG. 9  shows an example of a file selection window open on the projection display screen SR of the projector  10 .  FIG. 10  shows an exemplified display of a password input box PB 1  open on the projection display screen SR of the projector  10 .  FIG. 11  shows an exemplified display of a failed authentication display box PB 2  open on the projection display screen SR of the projector  10 .  FIG. 12  shows an exemplified display of a reproduction forbid display box PB 3  open on the projection display screen SR of the projector  10 . 
     The remote control  40  used for transmitting commands in this processing routine has numeral keys  401  of 1 to 5, which work as function keys to execute previously allocated functions, as shown in  FIG. 7 . The remote control  40  is also provided with a joy stick  402  for shifting the cursor or pointer position on the projection display screen SR in the vertical direction and in the horizontal direction, a Menu Call key  403 , and an Enter key  404 . Prior to start of this processing routine, the Menu Call key  403  of the remote control  40  is operated to project and display a menu window shown in  FIG. 8 . 
     The first CPU  200  of the projector  10  waits for input of a file selection requirement through operations of the remote control  40  (step S 200 : No). When detecting input of a file selection requirement (step S 200 : Yes), the first CPU  200  requires the second CPU  300  to project and display a file selection window shown in  FIG. 9  (step S 210 ). The first CPU  200  detects input of the file selection requirement in response to a press of the Enter key  404  while a menu bar MB 1 , that is, a menu option ‘2. File Selection’, is highlighted through the operation of the joy stick  402  on the menu window shown in  FIG. 8 . 
     The first CPU  200  determines whether or not input of a selected file reproduction requirement is detected (step S 220 ). The first CPU  200  detects input of the selected file reproduction requirement in response to a press of the Enter key  404  while a menu bar MB 2 , that is, a desired file option ‘2. *****.ppt’, is highlighted through the operation of the joy stick  402  on the file selection window shown in  FIG. 9 . 
     When detecting input of the selected file reproduction requirement (step S 220 : Yes), the first CPU  200  requires the second CPU  300  to project and display a password input box PB 1  shown in  FIG. 10  (step S 230 ). In the password input box PB 1 , input of a password is required. The password consisting of the combination of five numerals 1 to 5 is input through the operation of the function keys  401  on the remote control  40 . The first CPU  200  compares the input password with the preset password (step S 240 ). When both the passwords are coincident with each other (step S 240 : Yes), the first CPU  200  requires the graphics controller  210  to draw the selected file and starts reproduction of the selected file (step S 250 ). The video data drawn and generated by the graphics controller  210  are processed through the video signal processing circuit  310 , the LCD driving circuit  330 , the LCD  332 , and the projection optical system  360  of the projector module  30  and projected and displayed on the projection screen. 
     When the password input via the remote control  40  is not coincident with the preset password (step S 240 : No), the first CPU  200  increments a count Ce on an incoincidence counter that counts the frequency of incoincidence by one (step S 260 ). The count Ce should be a positive integral value. The first CPU  200  then determines whether or not the count Ce on the incoincidence counter is not less than 4 (step S 270 ). When the count Ce on the incoincidence counter is 3 or less (step S 270 : No), the first CPU  200  requires the second CPU  300  to project and display a failed authentication display box PB 2  shown in  FIG. 11  (step S 280 ). The first CPU  200  waits for another input of the password under the display of the failed authentication display box PB 2 . 
     When the count Ce on the incoincidence counter is 4 or greater (step S 270 : Yes), on the other hand, the first CPU  200  requires the second CPU  300  to project and display a reproduction forbid display box PB 3  shown in  FIG. 12  (step S 290 ) and does not execute reproduction of the selected file. In order to prevent illegal accesses, reproduction of the selected file is prohibited if incoincidence of the password continues a predetermined number of times (four in this embodiment). In response to a click of an ‘OK’ button on the reproduction forbid display box PB 3  with the mouse  552  (the mouse pointer), the first CPU  200  shifts the processing to step S 300 . 
     The first CPU  200  resets the count Ce on the incoincidence counter to zero (step S 300 ), before exiting from this processing routine. 
     When detecting no input of the selected file reproduction requirement (step S 220 : No), the first CPU  200  immediately exits from this processing routine. This corresponds to, for example, a case of confirming files stored in the external storage device  41  of the projector  10 . 
     As described above, the arrangement of the first embodiment enables display data (files) to be transferred to and stored in the external storage device  41  of the projector  10  via the network line NL. Data files required for presentation may be stored in advance in the external storage device  41  of the projector  40 . This arrangement enables the projector  10  to be used alone for presentation without connecting with the personal computer PC. This desirably saves the labor and time for connection with the personal computer PC every time the projector  10  is used. 
     In the arrangement of the first embodiment, the drag and drop of the file icon FL onto the projector icon PJ on the display  54  of the personal computer PC enables the corresponding selected file to be transferred to and stored in the projector  10 . This ensures the visual check on the file transfer and storage operation. Prior to start of the file transfer from the personal computer PC to the projector  10 , the password setting window PW is open on the display  54  to set the password mapped to the selected file. This ensures the secrecy of the file. 
     In the arrangement of the first embodiment, in response to a file reproduction instruction, the projector  10  displays the password input box PB 1  on the projection display screen SR to wait for input of the password. The projector  10  starts reproduction of the selected file only when the input password is coincident with the preset password. This arrangement effectively prevents any file stored in the external storage device  41  from being illegally reproduced by any third person, and thus assures the secrecy of files. Even when a large number of people share one projector PJ, there is no need of eliminating the existing files from the external storage device  41  on every occasion of use. Namely the secrecy of the respective files is desirably kept even when a plurality of people share the projector  10  with the existing files stored in the external storage device  41 . 
     In the technique of the first embodiment, the preset password is a combination of available numerals (1 to 5) on the remote control  40 . There is accordingly no need of using a separate input device other than the remote control  40  to input the password on the projector  10 . 
     Second Embodiment 
     The following describes another projector in a second embodiment of the present invention. The description mainly regards the differences in the structure of the projector of the second embodiment. The constituents of the projector of the second embodiment that are identical with those of the projector of the first embodiment are expressed by the same symbols as those used in the first embodiment and are not specifically described here. 
     D. Layout of Projector in Second Embodiment 
       FIG. 13  illustrates a layout of the projector in the second embodiment of the present invention. The projector  10  may be, for example, suspended from the ceiling as shown in  FIG. 13 . The projector  10  is connected to the network line NL and transmits data and commands to and from a server computer SC and a client computer CC via the network line NL. The user can input commands and data into the projector  10  with an external wireless input device  40 , such as a wireless keyboard  401  and a wireless mouse  402 . Images supplied from a non-illustrated image supply apparatus to the projector  10  are projected on a projection screen SCR. 
     In the structure of the second embodiment, the ASP terminal module  20  functions as a Web server module. One of the functions of the Web server module distributes Web pages including working status information, which represent the working status of the projection display module. Web server applications for releasing Web pages are thus stored, in addition to the viewer applications and other applications, in the first ROM  202 . When the ASP terminal module  20  functions as the Web server module, the first CPU  200  reads a Web server application from the first ROM  202  and activates the Web server application to distribute specified Web page information to a Web client (also called a Web browser). 
     E. Control of Working State of Projector in Second Embodiment 
       FIG. 14  is a functional block diagram illustrating the construction of the ASP terminal module  20  functioning as the Web server module. The first CPU  200  executes the Web server application stored in the first ROM  202 , so that the ASP terminal module  20  functions as the Web server module. In the following discussion, the ASP terminal module  20  may be referred to as the Web server module  20 . The Web server module  20  mainly includes a controller  21  that controls the general operations, a working status information collecting unit  22 , a page information distribution unit  24 , a network input-output unit  26 , and a working state controller  27 . 
     The network input-output unit  26  functions to control the operations of the network I/F controller  220 . The working status information collecting unit  22  functions to collect information representing the working conditions of the projector module  30  and the ASP terminal module  20  as working status information  23 . The information representing the working conditions of the ASP terminal module  20  are stored in the first ROM  202  and the first RAM  204  (see  FIG. 2 ). The information representing the working conditions of the projector module  30  are stored in the second ROM  302  and the second Ram  304  (see  FIG. 2 ) and are transferred from the second CPU  300  via the I/O port  230 . 
     The page information distribution unit  24  functions to, in response to a requirement from the Web client (or the Web browser) executed in the client computer CC, select page information representing a corresponding Web page out of a page information database  25  and distribute the selected page information. The page information to be distributed may include the working status information  23  collected by the working status information collecting unit  22 . 
     The working state controller  27  functions to control the working state of the ASP terminal module  20  according to control information (a command) sent back from the Web browser, while supplying a control signal to the projector module  30  to control the working state of the projector module  30 . The projector module  30  controls a corresponding working condition in response to the supplied control signal. A Web page update command is sent back with the control information from the Web browser. When the working state controller  27  controls the working state, the working status information collecting unit  22  newly collects the working status information  23  and the page information distribution unit  24  distributes the page information including the newly collected working status information to update the Web page displayed on the Web browser. The working status information collecting unit  22  may monitor a change of the working state irrespective of the control by the working state controller  27  and newly collect the working status information if there is any change. 
     The working state controller  27  corresponds to the control signal supply module of the present invention, and the working status information collecting unit  22  and the page information distribution unit  24  correspond to the page information updating module of the present invention. 
     The following describes a procedure of setting various working conditions of the projector from the client computer CC with referring to  FIGS. 15 to 19 . In the Web browser executed by the client computer CC (hereinafter may simply be referred to as the ‘Web browser CC’), in response to input of a URL (Uniform Resource Locator) assigned to the Web server module  20 , the Web server module  20  distributes corresponding homepage information to the Web browser CC. The Web browser CC then opens a homepage shown in  FIG. 15 . 
     When the user selects and clicks a working state setting icon WC on the homepage displayed on the Web browser CC, the URL assigned to the clicked working state setting icon WC is specified. The Web server module  20  selects page information corresponding to the specified URL out of the page information database  25  and distributes the selected page information to the Web browser CC. The Web browser CC opens a working state setting menu window shown in  FIG. 16  as a Web page. FIG.  16  shows a Web Menu including five option buttons, a Video button VB, an Audio button AB, a Advanced Setting button HB, an Information button IB, and a Reset button RB. 
     When the user presses a desired option button among the five option buttons, the URL assigned to the pressed option button is specified. The Web server module  20  selects page information corresponding to the specified URL out of the page information database  25  and distributes the selected page information to the Web browser CC. A corresponding setting window is then displayed on the Web browser CC as the Web page. For example, in response to a press of the Video button VB, a video setting window shown in  FIG. 17  is open.  FIG. 17  shows a menu including four menu options, that is, ‘Brightness’, ‘Contrast’, ‘Sharpness’, and ‘Gamma Correction’ as image-related controllable working conditions. 
     A ‘Brightness’ field includes a working state display scale expressed by six brightness levels, as well as a Brightness Down button IDB on the left side of the working state display scale and a Brightness Up button IUB on the right side of the working state display scale. ‘Contrast’ and ‘Sharpness’ fields respectively have the same arrangement as that of the ‘Brightness’ field. 
     A ‘Gamma Correction’ field includes three radio buttons corresponding to three different levels, ‘Dynamic’, ‘Normal’, and ‘Natural’. 
     In another example, in response to a press of the Audio button AB in  FIG. 16 , an audio setting window shown in  FIG. 18  is open.  FIG. 18  shows a menu including three menu options ‘Volume’, ‘High Tone’ and ‘Low Tone’ as audio-related controllable working conditions. ‘Volume’, ‘High Tone’ and ‘Low Tone’ fields respectively have the same arrangement as that of the ‘Brightness’ field. 
     A corresponding Web window is displayed in response to a press of one of the other option buttons shown in  FIG. 16 , that is, the Advanced Setting button HB, the Information button IB, and the Reset button RB. In response to a press of the Advanced Setting button HB, various setting windows are open for projector-related settings, such as settings of color and projector installation environment (for example, suspended from the ceiling or rear projection). In response to a press of the Information button IB, projector-related information, for example, a lamp-on time, an image type, and a resolution, is displayed. In response to a press of the Reset button RB, a setting window is open to initialize the working conditions of the projector. 
     A process of changing the working condition of the projector  10  is discussed below with an example of changing the brightness of the image on the video setting window shown in  FIG. 17 . The Brightness Up button IUB is pressed to heighten the brightness, whereas the Brightness Down button IDB is pressed to lower the brightness. One press of the Brightness Up button IUB causes control information for heightening the brightness level by one step (brightness up command) to be transmitted to the Web server module  20 . Simultaneously a Web page update command is transmitted to once close the video setting window displayed on the Web browser CC as the Web page. 
     The working state controller  27  of the Web server module  20  (see  FIG. 14 ) identifies the transmitted control information (command) as either information addressed to the projector module  30  or information addressed to the ASP terminal module  20 . The brightness up command is identified as the command addressed to the projector module  30  and is thus transferred to the projector module  30 . The projector module  30  heightens the brightness of the image in response to this command. Namely the working condition of the projector module  30  is changed. The working status information collecting unit  22  ( FIG. 14 ) newly collects information representing the updated working condition of the projector module  30  as the working status information  23 . The page information distribution unit  24  ( FIG. 14 ) then distributes the page information including the newly collected working status information to the Web browser CC. The video setting window is open again on the Web browser CC as the Web page updated according to the newly collected working status information  23 .  FIG. 19  shows the video setting window after a rise of the brightness level by one step. The lit-up radio button on the brightness display scale is shifted to the one-step up position from the position of  FIG. 17  (namely, the position of the closed circle is shifted rightward by one from the position of  FIG. 17 ). 
     Although the above description regards the process of changing the brightness of the image in the video setting window, the similar procedure is applied for the setting in various other setting windows. 
     As described above, in the arrangement of the second embodiment, various working conditions of the projector  10  are regulated according to the user&#39;s input control information on the Web page distributed to and displayed on the Web browser, which is executed in the client computer CC, by the Web server module  20 . This arrangement enables the user who is apart from the projector  10  to readily control the working conditions of the projector  10 . Compared with the prior art projectors, the projector of this embodiment thus enhances the operatability for controlling the working conditions thereof. 
     The Web page discussed in the second embodiment is just an example for the purpose of describing the present invention, and the present invention is not restricted to this example in any sense. 
     F. Third Embodiment 
     The following describes still another projector in a third embodiment of the present invention.  FIG. 20  illustrates a projection display system in the third embodiment of the present invention. This projection display system includes a projector PJ 1  (that is, a projection-type display apparatus PJ 1 ) and a computer PC 1 , which are connected to each other via a network NW, such as a LAN. The computer PC 1  shown in  FIG. 20  corresponds to the external input apparatus of the present invention. 
     Referring to  FIG. 20 , the computer PC 1  is provided with a mouse MS as a pointing device. As discussed later, operation information OPS corresponding to an operation of the mouse MS is supplied to the projector PJ 1  via the network NW. The projector PJ 1  carries out a preset series of processing with regard to an image to be projected and displayed, based on the operation information OPS. For example, the projector PJ 1  causes a pointer image PPJ to be generated in an original image ORG displayed on a screen SC, based on the operation information OPS supplied via the network NW. In the embodiment of  FIG. 20 , the computer PC 1  supplies the operation information OPS to the projector PJ 1 , but does not supply video data representing the original image ORG and the pointer image PPJ. 
       FIG. 21  schematically illustrates the structure of the projector PJ 1  shown in  FIG. 20 . The projector PJ 1  includes a CPU  1100 , an external storage device  1102 , an internal storage device  1104  like a ROM and a RAM, an analog video signal input module  1108 , an image processing module  1110 , a liquid crystal light valve driving module  1120 , a liquid crystal light valve  1130 , an ornamental image processing module  1140 , a menu image processing module  1150 , a remote control signal processing module  1160 , a scanning device  1170  that reads, for example, video data stored in a memory card MC, and a network interface module  1180 . The CPU  1100 , the external storage device,  1102 , the internal storage device  1104 , the image processing module  1110 , the ornamental image processing module  1140 , the menu window processing module  1150 , the remote control signal processing module  1160 , the scanning device  1170 , and the network interface module  1180  are mutually connected via a bus  1100   b . The liquid crystal light valve  1130  is illuminated substantially uniformly with a lighting optical system  11200 . Image rays formed by the light crystal light valve  1130  are projected on the screen SC by the function of a projection optical system  1220 . In the illustration of  FIG. 21 , the optical systems  11200  and  1220  are simplified. 
     An input device, such as a keyboard and a mouse, may be connected to the projector PJ 1  of the embodiment via a non-illustrated interface. 
     The analog video signal input module  1108  receives an analog video signal AV 1  supplied from an external image supply apparatus (not shown). The analog video signal AV 1  may be, for example, an RGB signal representing a computer image supplied from a personal computer or a composite video signal representing a motion picture supplied from a video recorder or a television set. The analog video signal input module  1108  functions to carry out A-D conversion of the input analog video signal AV 1  and output a digital video data DV 1 . 
     The image processing module  1110  functions to combine original video data with ornamental video data and thereby generate composite video data. This causes the pointer image PPJ (see  FIG. 20 ) expressed by the ornamental video data to be superimposed on the original image ORG (see  FIG. 20 ) expressed by the original video data. The original video data are temporarily written into a non-illustrated frame memory included in the image processing module  1110 . The image processing module  1110  combines the original video data with the ornamental video data when reading the original video data from the frame memory, and supplies resulting composite video data DDV to the liquid crystal light valve driving module  1120 . 
     The original video data may be the video data DV 1  supplied from the analog video signal input module  1108 , video data supplied from the network via the network interface module  1180 , menu video data supplied from the menu image processing module  1150 , and video data read from the memory card MC supplied from the scanning device  1170 . The ornamental video data is supplied from the ornamental image processing module  1140 . 
     The ornamental image represents an image prepared independently of the original image (that is, an additional image), and is superimposed on (added to) the original image to be projected and displayed on the screen SC. 
     The liquid crystal light valve driving module  1120  generates image display data SD according to the composite video data DDV supplied from the image processing module  1110 . The liquid crystal light valve  1130  is driven in response to the image display data SD. The liquid crystal light valve  1130  modulates the light emitted from the lighting optical system  11200  to generate image rays representing an image. 
     The ornamental image processing module  1140  functions to generate ornamental video data representing an ornamental image and supply the ornamental video data to the image processing module  1110 . More concretely the ornamental image processing module  1140  generates diverse ornamental video data, for example, pointer video data representing the pointer image PPJ (see  FIG. 20 ) and data representing specific shaped images (for example, finger-pointing images) and drawing images (for example, box images and frame images) of desired sizes generated by specifying the range with the pointer image PPJ, and supplies the generated ornamental video data to the image processing module  1110 . 
     The menu image processing module  1150  functions to generate menu video data representing a menu image and supply the menu video data to the image processing module  1110 . The user specifies various settings relating to the projector PJ 1  according to the menu image. 
     The network interface module  1180  functions to connect the projector PJ 1  with the LAN and supply the operation information OPS, which has been transmitted from the computer PC 1  via the LAN, to the CPU  1100  via the bus  1100   b . The CPU  1100  controls the image processing module  1110 , the ornamental image processing module  1140 , and the menu image processing module  1150 , based on the supplied operation information OPS. In the case where the operation information OPS includes positional information representing the position of the pointer image PPJ ( FIG. 20 ) to be superimposed on the original image ORG, the ornamental image processing module  1140  transmits the pointer video data to the image processing module  1110 , based on the operation information (positional information) OPS. The image processing module  1110  combines the pointer video data with the original video data according to the operation information (positional information) OPS, so that the pointer image PPJ is superimposed at the preset position on the original image ORG. The network interface module  1180  also functions to supply video data, which has been transmitted via the LAN, to the image processing module  1110  as the original video data as discussed later. 
     The remote control signal processing module  1160  ( FIG. 21 ) controls the functions of the respective constituents of the projector PJ 1  in response to control signals sent from a remote control RM. For example, the remote control signal processing module  1160  controls the functions of the ornamental image processing module  1140  in response to a control signal sent from the remote control RM and causes the pointer image PPJ to be superimposed at a preset position on the original image ORG. In the projection display system of this embodiment, the mouse MS (see  FIG. 20 ) of the computer PC 1  connecting with the LAN may be operated in place of the remote control RM to superimpose the pointer image PPJ at the preset position on the original image ORG. 
     The CPU  1100 , the image processing module  1110 , and the ornamental image processing module  1140  shown in  FIG. 21  correspond to the video data generation module of the present invention. 
       FIG. 22  schematically illustrates the structure of the computer PC 1  shown in  FIG. 20 . The computer PC 1  includes a CPU  1300 , an external storage device  1310 , a ROM  1320 , a RAM  1330 , a display unit  1350 , and an input unit  1360  like a mouse MS and a keyboard KB. The computer PC 1  is also provided with a network interface module  1380  for connection with the LAN. 
     A programs for actualizing the functions of an operation information generation module  1332  is stored in the RAM  1330 . The operation information generation module  1332  functions to detect a user&#39;s operation of the input unit  1360  and generate the operation information OPS based on the result of the detection. The generated operation information OPS is supplied to the projector PJ 1  via the network interface module  1380 . 
     The computer program for actualizing the functions of the operation information generation module  1332  is recorded in a computer readable recording medium, such as a flexible disk or a CD-ROM. The computer reads the computer program from the recording medium and transfers the computer program to either the internal storage device or the external storage device. The computer program may be supplied to the computer via a communication path. A microprocessor in the computer executes the computer program stored in the internal storage device to actualize the functions of the computer program. Otherwise the computer may directly read and execute the computer program recorded in the recording medium. 
     In the specification hereof, the term ‘computer’ is the concept including the hardware structure and the operating system and represents the hardware structure working under control of the operating system. In the case where the operating system is not required but an application program alone actuates the hardware structure, the hardware structure itself is equivalent to the computer. The hardware structure includes at least a microprocessor like a CPU and means for reading a computer program recorded in a recording medium. The computer program includes program codes, which cause the computer to attain the functions of the respective means. Part of the functions may be actualized by the operating system, instead of the application program. 
     Available examples of the ‘recording medium’ in the present invention include flexible disks, CD-ROMs, magneto-optic discs, IC cards, ROM cartridges, punched cards, prints with barcodes or other codes printed thereon, internal storage devices (memories like a RAM and a ROM) and external storage devices of the computer, and a variety of other computer readable media. 
       FIG. 23  shows one application of the projection display system of  FIG. 20 . In the projection display system of  FIG. 23 , a plurality of computers PC 1 , PC 2 , . . . are connected to one projector PJ 1  via a LAN. In this projection display system, for example, when the mouse MS is moved in the first computer PC 1 , operation information OPS generated in response to the movement of the mouse MS is supplied to the projector PJ 1  via the LAN. The projector PJ 1  then moves the pointer image PPJ superimposed on the original image ORG displayed on the screen SC, in connection with the movement of the mouse MS. Such operations are also attained in the other computers PC 2 , PC 3  . . . . This projection display system is effectively used for sequential presentations made by a plurality of people with one projector PJ 1 . Since there is no need of transferring one remote control RM among the respective presenters, the sequential presentations are performed smoothly. 
       FIG. 24  is a flowchart showing series of processing executed by the projector PJ 1  and the computer PC 1 . The projector PJ 1  displays the original image ORG on the screen SC at step T 101 . 
     At step S 1101 , the computer PC 1  activates an operation information generation program to generate the operation information OPS in response to an operation of the input unit  1360 . The operation information generation program stored in the external storage device  1310  shown in  FIG. 22  is expanded in the RAM  1330  and works as the operation information generation module  1332 . Activation of the operation information generation program causes an Operation Detection window DW to be open on the display unit  1350  of the computer PC 1 . 
       FIG. 25  shows the Operation Detection window DW open on the display unit  1350  of the computer PC 1 . The Operation Detection window DW and a Memo window MW for a memorandum, for example, in which the contents of a presentation are written, are open on the display unit  1350  shown in  FIG. 25 . 
     The Operation Detection window DW includes a ‘PJ Selection’ button B 1 , a ‘Resolution Selection’ button B 2 , a ‘Menu’ button B 3 , a ‘Start’ button BS, an ‘End’ button BE, and an operation information generation area GA. The operation information generation area GA represents an area in which the operation information OPS is generated in response to each operation of the mouse MS. In the example of  FIG. 25 , a pointer image PPC corresponding to the mouse MS is movable over the whole area of the display unit  1350 . The operation information OPS in response to each operation of the mouse MS is generated, however, only when the pointer image PPC is present in the operation information generation area GA. While the user operates the mouse MS with the pointer image PPC out of the operation information generation area GA, the operation information OPS corresponding to the operation of the mouse MS is not generated. The user can thus perform other operations with the mouse MS, for example, an operation of changing the memorandum shown in the Memo window MW. 
     Referring back to  FIG. 24 , settings of the projector PJ 1  are specified at step S 1102 . In a concrete procedure, the user selects a desired projector and sets the resolution suitable for the selected projector. 
     The user actuates the ‘PJ Selection’ button B 1  included in the Operation Detection window DW to select the desired projector. A selection field (not shown) for selecting the projector is displayed in response to a click of the ‘PJ Selection’ button B 1  with the mouse MS. In the case where a plurality of projectors are connected to the LAN, information on the plurality of projectors is displayed in the selection field. The user selects the desired projector ‘PJ 1 ’ among one or plural projectors displayed in the selection field. 
     The user then actuates the ‘Resolution Selection’ button B 2  included in the Operation Detection window DW to set the resolution suitable for the projector PJ 1 . A selection field (not shown) for selecting the resolution is displayed in response to a click of the ‘Resolution Selection’ button B 2  with the mouse MS. For example, when the effective display area of the liquid crystal light valve  1130  ( FIG. 21 ) in the projector PJ 1  has a resolution XGA (1024×768), ‘XGA’ is selected as the resolution of the projector PJ 1 . Setting the resolution of the projector PJ 1  causes the image area of the original image ORG projected and displayed on the screen SC to be mapped to the operation information generation area GA. Namely the positional relation of the pointer image PPC in the operation information generation area GA is made substantially coincident with the positional relation of the pointer image PPJ in the original image ORG. 
     On conclusion of the settings with regard to the projector PJ 1  at step S 1102 , the computer PC 1  outputs start information representing a start of transmission of the operation information OPS at step S 1103 . This is executed when the user actuates the ‘Start’ button BS included in the Operation Detection window DW. When the user clicks the ‘Start’ button BS, the start information is output from the network interface module  1380  to the network interface module  1180  of the projector PJ 1  via the LAN. 
     When receiving the start information, the projector PJ 1  prepares for display of the pointer image PPJ on the original image ORG in a superimposing manner at step T 102 . In a concrete procedure, the CPU  1100  causes the ornamental image processing module  1140  to generate pointer video data, based on the start information transmitted to the network interface module  1180 . 
     In the application of  FIG. 23 , when the start information is transmitted from the first computer PC 1  to the projector PJ 1 , the projector PJ 1  carries out the processing only based on the operation information OPS output from the first computer PC 1  and ignores information sent from any other computers PC 2 , PC 3 , . . . until output of end information (step S 1108 ) discussed later. Namely the first computer PC 1  exclusively uses the projector PJ 1 . 
     At step S 1104 , the user operates the mouse MS functioning as the input unit  1360 . Here the operation of the mouse MS may be a motion of the mouse MS or a press of a switch on the mouse MS. 
     At step S 1105 , the computer PC 1  detects the operation of the mouse MS functioning as the input unit  1360 . At subsequent step S 1106 , the computer PC 1  generates the operation information OPS, based on the result of the detection at step S 1105 . 
     As described previously, the operation information generation module  1332  of this embodiment detects the operation of the mouse MS only when the pointer image PPC corresponding to the mouse MS is present in the operation information generation area GA on the Operation Detection window DW. The position of the pointer image PPC in the operation information generation area GA is specified by coordinate values according to the preset resolution of the projector PJ 1  (step S 1102 ). In this embodiment, XGA (1024×768) is set to the resolution of the projector PJ 1 . The pointer images PPC present on the upper left corner, on the center, and on the lower right corner of the operation information generation area GA are respectively expressed by coordinate values (1,1), coordinate values (512,384), and coordinate values (1024,768). Such coordinate value information represents the positional information of the mouse MS and is output as the operation information OPS. 
     At step S 1107 , the computer PC 1  transmits the operation information OPS. The operation information OPS is converted into a data format for the network and output by the network interface module  1380  (see  FIG. 22 ). 
     The projector PJ 1  displays an image based on the operation information OPS at step T 103 . In a concrete procedure, the pointer image PPJ is displayed at a predetermined position in the original image ORG (that is, a position corresponding to the position of the pointer image PPC in the operation information generation area GA), based on the operation information OPS. The computer PC 1  supplies the operation information OPS to the projector PJ 1 , but does not supply pointer video data representing the pointer image PPJ. 
     Iterative execution of steps S 1104  to S 1107  and T 103  enables the pointer image PPJ in the original image ORG projected and displayed on the screen SC to be moved in connection with the movement of the mouse MS. 
     At step S 1108 , end information representing an end of transmission of the operation information OPS is output. This is executed when the user actuates the ‘End’ button BE included in the Operation Detection window DW. When the user clicks the ‘End’ button BE, the end information is output from the network interface module  1380  to the network interface module  1180  of the projector PJ 1  via the LAN. 
     When receiving the end information, the projector PJ 1  eliminates the pointer image PPJ superimposed on the original image ORG at step T 104 . In a concrete procedure, the CPU  1100  causes the ornamental image processing module  1140  to stop the output of the pointer video data, based on the end information transmitted to the network interface module  1180 . 
     The above description regards the operation of simply moving the mouse MS at step S 1104 . In the case where the user moves the mouse MS while pressing the switch on the mouse MS, an area may be specified in the projected and displayed image ORG. In the projector PJ 1  of this embodiment, an ornamental image different from the pointer image, for example, a box image or a frame image, may be superimposed in the specified area on the original image ORG. As clearly understood from such discussion, not only the positional information of the mouse MS but switch information of the mouse MS is generated as the operation information OPS at step S 1106 . 
       FIGS. 26A-26F  show a process of superimposing a box image PB on the original image ORG by utilizing the pointer image PPJ in the original image ORG. The size of the box image PB is determined by specifying two opposing vertexes (a starting point and an end point) of the box image PB in the original image ORG.  FIGS. 26A-26C  show the operation information generation area GA included in the Operation Detection window DW ( FIG. 25 ).  FIGS. 26D-26F  show the original image ORG displayed on the screen SC by the projector PJ 1 . 
     In  FIG. 26A , the user operates the mouse MS of the computer PC 1  to specify a starting point P 1 C for defining an area. In a concrete procedure, the use moves the mouse MS to move the pointer image PPC to the starting point P 1 C and presses the switch on the mouse MS at the starting point P 1 C. At this moment, a starting point P 1 J is specified by the pointer image PPJ in the original image ORG as shown in  FIG. 26D . When the starting point P 1 J is specified in the original image ORG, a starting point image PS representing the starting point of the box image PB is superimposed at the position of the starting point P 1 J. 
     In  FIG. 26B , the user moves the mouse MS to an end point P 2 C of the area while pressing the switch on the mouse MS. At this moment, a frame defined by a line segment connecting the starting point P 1 C with the end point P 2 C as a diagonal is shown by the broken line in the operation information generation area GA. In response to the appearance of the starting point image PS, an end point image PE replaces the pointer image PPJ and is used to specify an end point P 2 J in the original image ORG as shown in  FIG. 26E . 
     In  FIG. 26C , the user stops pressing the switch on the mouse MS. At this moment, the box image PB is superimposed in the area defined by the starting point P 1 J and the end point P 2 J on the original image ORG as shown in  FIG. 26F . 
     Ornamental video data representing the ornamental images, that is, the starting point image PS, the end point image PE, and the box image PB are prepared by the ornamental image processing module  1140  ( FIG. 21 ) and supplied to the image processing module  1110 . 
     The type of the ornamental image, such as the box image PB, superimposed on the original image ORG is specified in advance by actuating the ‘Menu’ button B 3  included in the Operation Detection window DW ( FIG. 25 ). When the user clicks the ‘Menu’ button B 3  in the computer PC 1 , menu display start information is output to the projector PJ 1  via the LAN. The CPU  1100  in the projector PJ 1  controls the menu image processing module  1150  and the image processing module  1110 , based on the menu display start information transmitted to the network interface module  1180 , and projects and displays a menu image as the original image ORG on the screen SC. The user selects a desired type of the ornamental image with the pointer image PPJ superimposed on the original image ORG (menu image). One modified arrangement may use the remote control RM to display the menu image and select the desired type of the ornamental image. 
     The above description regards the case of operating the mouse MS as the input unit  1360  of the computer PC 1 . The operation information OPS is also generated in response to an operation of the keyboard KB functioning as the input unit  1360 . When the user operates the keyboard KB at step S 1104 , the operation information generation module  1332  detects the key operation and generates the operation information OPS including key information based on the result of the detection at steps S 1105  and S 1106 . At step T 103 , the projector PJ 1  displays an image, based on the operation information OPS transmitted from the computer PC 1  (step S 1107 ).  FIG. 27  shows an image projected and displayed in response to a user&#39;s operation of the keyboard KB as the input unit  1360 . In the example of  FIG. 27 , a symbol image PM consisting of letters ‘Here!’ corresponding to the key information is superimposed in the vicinity of the position specified by the pointer image PPJ on the original image ORG. When the operation information OPS includes the key information, a symbol image of letters and the like is superimposed on the original image ORG. This enhances the effects of the presentation. Symbol video data representing the symbol image is prepared by the ornamental image processing module  1140  and supplied to the image processing module  1110 . 
     In the third embodiment, the operation of the keyboard KB is also detected only when the pointer image PPC is present in the operation information generation area GA on the Operation Detection window DW ( FIG. 25 ). The pointer image PPC out of the operation information generation area GA thus enables the user to perform other operations with the keyboard KB, for example, an operation of editing the contents of the memorandum in the Memo window MW. 
     As described above, the projection display system of the third embodiment includes the external input apparatus PC 1  and the projector PJ 1  that are connected with each other via the network NW. The external input apparatus PC 1  has the operation information generation module  1332 , which detects a user&#39;s operation of the input unit  1360  and generates the operation information based on a result of the detection. The projector PJ 1  has the video data generation module  1100 ,  1110 , and  1140  that generates video data DDV representing a resulting image, which is obtained by superimposing an ornamental image expressed by ornamental video data at a predetermined position on an original image expressed by original video data, based on the operation information OPS transmitted via the network NW. As mentioned above, the external input apparatus PC 1  supplies the operation information OPS to the projector PJ 1 , but does not supply the ornamental video data representing the ornamental image to be displayed on the original image. The user can thus readily make the ornamental image superimposed on the original image by a simple operation of the input unit  1360  incorporated in the external input apparatus PC 1 . 
     G. Fourth Embodiment 
     The technique of the third embodiment causes the projector PJ 1  (or the projection display apparatus PJ 1 ) to superimpose the pointer image PPJ or an ornamental image different from the pointer image on the projected and displayed original image ORG, in response to a user&#39;s operation of the input unit  1360  of the computer PC 1  (see  FIG. 22 ). Another application allows the user to directly edit the contents of the projected and displayed original image ORG through operations of the input unit  1360  of the computer PC 1 . 
     The projector PJ 1  ( FIG. 21 ) stores an application program in the external storage device  1102  to attain such functions. When the projector PJ 1  activates the application program stored in the external storage device  1102 , the application program is expanded in the internal storage device (RAM)  1104  and executed by the CPU  1100 . Execution window data generated by the application program is supplied to the image processing module  1110  and used as the original video data. This arrangement enables the user to directly edit the contents of the original image (execution window) ORG generated by the application program through operations of the input unit  1360  of the computer PC 1 . 
     The recent trend promotes the use of application programs by the SBC (Server Based Computing) method, although the application programs have conventionally been used by the download method. In the download method, the user dynamically downloads a desired application program from a server to a client machine and installs the downloaded application program on the client machine, so as to attain use of the application program. 
     In the SBC method, on the other hand, the user causes an application program to be executed on a server and utilizes an execution window of the application program on the server via a client machine. In this application, operation information of a keyboard or a mouse is supplied from the client machine to the server, while update data of the execution window is supplied from the server to the client machine. This arrangement separates the operations of the application program from the client machine, thus ensuring the use of the application program irrespective of the performance of the client machine. The execution window data is supplied in a specific format, and the client machine displays the execution window based on the supplied data in the specific format. 
     In the structure of the fourth embodiment, the projector PJ 1  (projection-type display apparatus PJ 1 ) may function as the client machine. In this case, there is no need of storing the application program in the projector PJ 1 . This accordingly enables reduction of the required storage capacities of the external storage device  1102  and the internal storage device  1104 . 
       FIG. 28  shows a projection display system in the fourth embodiment. The projection display system includes a projector PJ 1  (projection-type display apparatus PJ 1 ), a computer PCs, and a server SB. The projector PJ 1 , the computer PC 1 , and the server SB are mutually connected via a network NW. 
     The projector PJ 1  functions as the client machine discussed above and causes an execution window of an application program supplied from the server SB to be projected and displayed on a screen SC. The internal structure of the projector PJ 1  is substantially similar to that of  FIG. 21  and is thus not specifically described here. The difference is that the network interface module  1180  (see  FIG. 21 ) has a non-illustrated internal viewer module, which prepares execution window data representing the execution window based on supplied data DT in a specific format. The execution window data is supplied to the image processing module  1110  (see  FIG. 21 ) and used as the original video data. 
     Like the system including the projector PJ 1  that stores the application program in its external storage device  1102 , in this projection display system, the user operates the input unit  1360  (see  FIG. 22 ) of the computer PC 1  to directly edit the contents of the projected and displayed original image (execution window) ORG. 
       FIGS. 29A-29C  show a series of processing to directly edit the contents of the original image ORG projected and displayed on the screen SC. In the example of  FIGS. 29A-29C , an execution window generated by a word processing program is displayed as the original image ORG. 
     In the state of  FIG. 29A , the user moves a mouse MS attached to the computer PC 1  to superimpose a pointer image PPJ at a desired position on the projected and displayed original image (execution window) ORG. Like the first embodiment, the operation information OPS that is supplied from the computer PC 1  and includes positional information is used for the process of superimposing the pointer image PPJ in the projector PJ 1 . In this state shown in  FIG. 29A , the pointer image PPJ is superimposed at the position of a letter ‘M’ on the original image ORG. 
     In the state of  FIG. 29B , the user presses (clicks) a switch mounted on the mouse MS and causes a cursor CS to be displayed at a desired position in the original image (execution window) ORG. The operation information that is supplied from the computer PC 1  and includes switch information is first supplied to the projector PJ 1 , which then transmits the supplied operation information OPS to the server SB via the network NW. The server SB causes the cursor to be displayed at a desired position in the execution window generated by the word processing program, based on the operation information OPS including the positional information of the mouse MS and the switch information. The server SB supplies the updated window with the cursor to the projector PJ 1  via the network NW, and the projector PJ 1  projects and displays the updated window as the original image ORG on the screen SC. In this state shown in  FIG. 29B , the projector PJ 1  superimposes the pointer image PPJ on the original image (updated window) ORG, based on the operation information OPS. 
     In the state of  FIG. 29C , the user operates a key on a keyboard KB attached to the computer PC 1 , so as to input a letter or symbol at the cursor position in the original image ORG. The operation information OPS that is supplied from the computer PC 1  and includes key information is first supplied to the projector PJ 1 , which then transmits the supplied operation information OPS to the server SB via the network NW. The server SB inputs the letter or symbol at the cursor position in the execution window generated by the word processing program, based on the operation information OPS including the key information of the keyboard KB. The server SB supplies the edited updated window to the projector PJ 1  via the network NW, and the projector PJ 1  projects and displays the updated window as the original image ORG on the screen SC. In this state shown in  FIG. 29C , the displayed original image (updated window) ORG includes a letter ‘L’ inserted between letters ‘K’ and ‘M’. 
     As shown in  FIGS. 29A to 29C , the user operates the input unit  1360  attached to the computer PC 1  to directly edit the contents of the projected and displayed image (execution window) ORG. In the example of  FIGS. 29A-29C , the projector PJ 1  projects and displays the execution window of the application program supplied from the server SB on the screen SC. The contents of the original image (execution window) ORG may also directly be edited when the projector PJ 1  projects and displays an execution window generated by an application program stored in the internal storage device  1104 . The advantage of the former arrangement is reduction of the required storage capacities of the external storage device  1102  and the internal storage device  1104  of the computer PC 1  as mentioned previously. The advantage of the latter arrangement is, on the other hand, that the projector PJ 1  is not required to transmit the operation information OPS, which has been supplied from the computer PC 1 , to the server SB. The CPU  1100  in the projector PJ 1  causes the network interface module  1180  to implement the supply of the operation information OPS from the projector PJ 1  to the server SB. 
     In the arrangement of the third embodiment, an ornamental image, which is different from the pointer image PPJ, is superimposed on the original image ORG through an operation of the input unit  1360  at the position of the pointer image PPJ superimposed on the original image ORG. In the arrangement of the fourth embodiment, on the other hand, the contents of the original image (execution window) ORG are edited through an operation of the input unit  1360  at the position of the pointer image PPJ superimposed on the original image ORG. The technique of the fourth embodiment may also superimpose an ornamental image, which is different from the pointer image PPJ, on the original image (execution window) ORG. The projector PJ 1  thus differentiates the process of superimposing the ornamental image on the original image ORG (ornament mode) from the process of directly editing the contents of the original image (execution window) ORG, based on the operation information OPS supplied after the superposition of the pointer image PPJ on the original image (ORG). The changeover of the processing mode is carried out on a menu window, and the CPU  1100  (see  FIG. 21 ) controls the respective elements according to the selected processing mode. 
     As described above, the projection display system of the fourth embodiment includes the external input apparatus PC 1  and the projector PJ 1  that are connected with each other via the network NW. The external input apparatus PC 1  has the operation information generation module  1332 , which detects a user&#39;s operation of the input unit  1360  and generates the operation information OPS based on a result of the detection. The projector PJ 1  has the video data processing module  1100 ,  1110 , and  1140  that generates video data DDV representing a resulting image, which is obtained by superimposing the pointer image at a predetermined position on the original image ORG and editing the contents of the original image (execution window) ORG, based on the operation information OPS supplied via the network NW. The user&#39;s operation of the input unit  1360  incorporated in the external input apparatus PC 1  enables the projector PJ 1  to readily execute the series of processing with regard to the contents of the image to be projected and displayed. 
     The projector, the projection display system, and the corresponding method and recording medium of the present invention are discussed above with the first through the fourth embodiments. These embodiments are, however, to be considered in all aspects as illustrative and not restrictive. There may be many modifications, changes, and alterations without departing from the scope or spirit of the main characteristics of the present invention. All changes within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Some examples of possible modification are given below. 
     (1) For example, in the first embodiment, the action of dragging and dropping the file ion FL onto the projector icon PJ on the display  54  sets the projector  10  as the destination of transfer and storage of the corresponding data file. The destination of transfer and storage may be set to the file server FS connecting with the network. For example, in the event that a large number of people make sequential presentations, the total capacity of file data may exceed the storage capacity of the external storage device  41  of the projector  10 . In such cases, required files may be stored in the file server FS. 
     (2) The following procedure may be applied for reproduction of a file. The projector  10  collects in advance the file information stored in the file server FS and displays the file information on the file selection window for selection of a file. When a file stored in the file server FS is selected, the projector  10  transmits a selected file transfer requirement to the file server FS. The projector  10  receives the selected file and carries out its projection and display. 
     (3) In the case where the personal computer PC has a PCMCIA slot, a PC memory card set in the PCMCIA slot may be set to the destination of the file transfer from the personal computer PC. In such cases, even when the projector  10  is not connected to the network, insertion of the PC memory card into the projector  10  after the file transfer from the personal computer PC to the PC memory card exerts the similar functions and effects to those discussed in the above embodiments. Setting a password is naturally required in the case of transferring a file to the PC memory card. 
     (4) The procedure of the first embodiment sets the password with the numerals 1 to 5. This range is set only corresponding to the available numerals on the remote control  40  as mentioned previously. The password may be set with numerals and letters other than 1 to 5 when the numerals and letters other than 1 to 5 are available on the remote control  40 . In one possible application, the remote control  40  has a liquid crystal window and a password of letters and numerals may be input through operations of the joy stick  402 . In another possible application, numerals and letters may be input through operations of a wireless keyboard. 
     (5) The technique of the first embodiment transfers the file with the password assigned thereto to the external storage device  41  of the projector  10 . In one modified arrangement, the personal computer PC encodes a file and transfers the encoded file to the projector  10 , which then decodes the transferred encoded file. Such modification enhances the security level in the process of the file transfer via the network line NL. 
     (6) The respective windows on the display  54  and on the projection display screen SR in the first embodiment are only illustrative and may adequately be changed and modified in practice. 
     (7) In the first embodiment, the ASP terminal module  20  is used as the representative of the network terminal module. The projector  10  is, however, not restricted to the ASP terminal. One modified arrangement receives application data (a file) via the network, opens the input file according to a viewer application, and projects and displays an image corresponding to the file. In such cases, the projector  10  may identify the type of the input file and automatically activate an optimum viewer application for the identified file type. Otherwise the server may transmit an activation command for activating an optimum viewer application simultaneously with the file to the projector  10 . 
     (8) In the first embodiment, each of the ASP terminal module  20  and the projector module  30  is provided with the CPU, the RAM, and the ROM. These elements may, however, be included in only the ASP terminal module  20 . In such cases, the CPU in the ASP terminal module  20  controls the projector module  30 . 
     (9) In the structure of the first embodiment, the projector module  30  includes the external video signal input terminal  312  and the external audio signal input terminal  322 . These elements may, however, be omitted in the case where the projector is exclusively used under the connection with the network. This is because the video data and the audio data are supplied via the network line NL in such cases. 
     (10) The various interface controllers are used in the structure of the first embodiment, but some of these internal controllers may be omitted according to the requirements, except the network interface controller  220 . 
     (11) In the third and the fourth embodiments, the computer PC 1  uses the mouse MS as the input unit  1360 . The mouse MS may be replaced by another pointing device, such as a tablet, track ball, a track pad, or a joy stick. These pointing devices have similar functions to those of the mouse MS and correspond to the pointing device of the present invention. 
     (12) In the third and the fourth embodiments, the superimposing position of the pointer image PPJ on the original image ORG is specified with the mouse MS functioning as the input unit  1360 . In the structure without the mouse MS as the input unit  1360 , the superimposing position of the pointer image PPJ may be specified with direction keys on the keyboard KB or with the ten keys on the keyboard KB. The direction keys and the ten keys on the keyboard KB also function as the pointing device of the present invention. 
     (13) In the third and the fourth embodiments, the positional information of the mouse MS included in the operation information OPS is expressed by coordinate values. The positional information may alternatively be expressed by vector values representing travels. In the latter case, two-way communication is desired. In the case where a series of positional information generated in response to a movement of the mouse MS is expressed by vector values, if part of the positional information is not transmitted to the projector PJ 1 , the positional relation of the pointer image PPC in the operation information generation area GA may not be coincident with the positional relation of the pointer image PPJ in the projected and displayed original image ORG. When the positional information is expressed by vector values representing travels, it is preferable that the projector PJ 1  transmits a receive signal to the computer PC every time the projector PJ 1  receives the operation information OPS. When no receive signal is given, the computer PC 1  again transmits the operation information OPS. In the case where a series of positional information generated in response to a movement of the mouse MS is expressed by coordinate values, on the other hand, even when part of the positional information is not transmitted to the projector PJ 1 , the positional relation of the pointer image PPC in the operation information generation area GA is substantially coincident with the positional relation of the pointer image PPJ in the projected and displayed original image ORG. Namely the expression of the positional information by coordinate values advantageously requires only one-way communication from the computer PC 1  to the projector PJ 1 . In general, the operation information OPS may be transmitted by one-way communication from the computer PC 1  to the projector PJ 1  or by two-way communication between the projector PJ 1  and the computer PC 1 . 
     (14) In the third and the fourth embodiments, the operation information generation module  1332  included in the RAM  1330  of the computer PC 1  causes the operation information generation area GA ( FIG. 25 ) to be displayed on the display unit  1350 . Display of the operation information generation area GA is, however, not essential. In the arrangement without the operation information generation area GA, the operation information OPS in response to an operation of the mouse MS is generated when the pointer image PPC is present at any place in the whole display area on the display unit  1350 . 
     (15) In the third and the fourth embodiments, the computer PC 1  has the display unit  1350 . The display unit  1350  may, however, be omitted. In general, the external input apparatus of the present invention should include the input unit, the operation information generation module for detecting a user&#39;s operation of the input unit and generating operation information based on the result of the detection, and the network interface module connecting with the network to supply the operation information to the projector via the network. 
     (16) In the third and the fourth embodiments, the user operates the input unit  1360  of the computer PC 1  to make an ornamental image, such as the pointer image PPJ, superimposed on the original image ORG or to directly edit the contents of the original image (execution window) ORG generated by an application program. The user may also cause the projector PJ 1  to carry out another series of processing on the image to be projected and displayed through operations of the input unit  1360  of the computer PC 1 . 
     When the projector PJ 1  requires input of the name of video data in the process of storing the video data in the external storage device  1102 , the user may operate the keyboard KB of the computer PC 1  to input and display the name of the video data on a data name input window. 
     When the projector PJ 1  requires input of a password in the process of using video data stored in a memory card MC as original video data, the user may operate the keyboard KB of the computer PC 1  to input and display the password on a password input window. It is preferable that a symbol like ‘*’ different from the symbol actually input by the user appears on the projected and displayed password input window. 
     In general, the video data generation module included in the projector of the present invention should carry out a predetermined process regarding contents of an image to be projected and displayed and generate resulting video data representing a projected and displayed image, based on the operation information generated in response to an operation of the input unit of the external input apparatus and transmitted to the network interface module via the network. 
     The predetermined process regarding the contents of the image to be projected and displayed, which is carried out by the video data generation module, represents a process of changing the display contents of the image (that is, the picture of the image) based on the operation information, for example, a process of causing an ornamental image expressed by ornamental video data to be superimposed at a predetermined position on an original image expressed by original video data. 
     (17) In the respective embodiments discussed above, part of the hardware structure may be replaced by the software configuration, while part of the software configuration may be replaced by the hardware structure. For example, part of the functions of the two CPUs  200  and  300  (see  FIG. 2 ) may be executed by specific hardware circuits. 
     (18) The above embodiments regard the projectors utilizing the transmission-type liquid crystal panel. The technique of the present invention is also applicable to other types of projectors, for example, those utilizing a reflection-type liquid crystal panel, those utilizing a Micromirror Device (trade mark by Texas Instruments Inc.), and those using a CRT.