Abstract:
An image display system in which an image display apparatus displays an image based on an image signal supplied from an image signal supply apparatus, wherein the image display apparatus includes: an image display unit displaying the image based on the image signal; an input source switching unit switching an input source of the image signal corresponding to the image displayed by the image display unit; a communication setup unit setting up a communication path with the image signal supply apparatus; a switching controller controlling the input source switching unit to switch the input source to the image signal supply apparatus in response to the notification that the communication setup unit sets up the communication path; and an image receiver receiving the image signal supplied from the image signal supply apparatus, and wherein the image signal supply apparatus includes an image transmitter transmitting the image signal to the image display apparatus via the communication path after the switching controller switches the input source.

Description:
[0001]    The entire disclosure of Japanese Patent Application No. 2009-015071 filed Jan. 27, 2009 is expressly incorporated by reference herein. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to an image display system having an image signal supply apparatus and an image display apparatus, and an image display apparatus. 
         [0004]    2. Related Art 
         [0005]    In presentations and the like, generally, a projector and a document camera are effectively used to project an image taken by the document camera by the use of the projector. As such an image display system, a configuration has been suggested in which the document camera and the projector are connected to a computer and the computer controls the document camera to take an image of an original material and controls the projector to project the image acquired by imaging when the document camera is turned on (see JP-A-2005-79730). According to this configuration, when the document camera is turned on, the original material can be automatically projected (see JP-A-2005-79730). 
         [0006]    However, in the related art, since the computer is disposed between the projector and the document camera, it is necessary to operate the computer and thus a user unaccustomed to a mechanical operation could not easily operate the system. 
       SUMMARY 
       [0007]    An advantage of some aspects of the invention is to allow a user unaccustomed to a mechanical operation to operate the system easily. 
         [0008]    The invention can be embodied in the following aspects. 
         [0009]    According to an aspect of the invention, there is provided an image display system in which an image display apparatus displays an image based on an image signal supplied from an image signal supply apparatus. Here, the image display apparatus includes: an image display unit displaying the image based on the image signal; an input source switching unit switching an input source of the image signal corresponding to the image displayed by the image display unit; a communication setup unit setting up a communication path with the image signal supply apparatus; a switching controller controlling the input source switching unit to switch the input source to the image signal supply apparatus in response to the notification that the communication setup unit sets up the communication path; and an image receiver receiving the image signal supplied from the image signal supply apparatus. In addition, the image signal supply apparatus includes an image transmitter transmitting the image signal to the image display apparatus via the communication path after the switching controller switches the input source. 
         [0010]    According to this configuration, when a communication path is set up between the image signal supply apparatus and the image display apparatus, the image display apparatus causes the switching controller to automatically switch the input source to the image signal supply apparatus. Thereafter, an image is transmitted from the image transmitter of the image signal supply apparatus and the image receiver of the image display apparatus receives the transmitted image. Accordingly, a user can simply display an image acquired by the image signal supply apparatus on the image display apparatus, only by connecting the image signal supply apparatus to the image display apparatus via a predetermined transmission cable. 
         [0011]    In the image display system, the image signal supply apparatus and the image display apparatus may include USB interfaces, respectively. In this case, the communication setup unit may include: a USB connection detector detecting a connection to the image signal supply apparatus via the USB interface; and a configuration setter acquiring a configuration descriptor of the image signal supply apparatus. Here, the image display apparatus may further include a stream negotiation unit determining a condition for transmitting and receiving the image on the basis of the configuration descriptor acquired by the configuration setter. 
         [0012]    According to this configuration, since the image display system includes the USB interfaces, it is possible to determine the condition for transmitting and receiving the image on the basis of the configuration descriptor based on the USB standard and acquired by the configuration setter, only by connecting the image signal supply apparatus to the image display apparatus via the USB cable as a predetermined transmission cable. As a result, the convenience to a user is excellent. 
         [0013]    In the image display system, the configuration descriptor may include at least type data for defining a color space of the image acquired by the image signal supply apparatus, and the image display apparatus may include an image color corrector correcting colors of the image received by the image receiver on the basis of the type data. 
         [0014]    According to this configuration, the image acquired by the image signal supply apparatus is corrected in color so as to be fully reproduced in the color gamut of the image display apparatus. Accordingly, the image display system is excellent in color reproducibility. 
         [0015]    In the image display system, the image display apparatus may further include: a standby state determining unit determining whether the image display apparatus is in a standby state until the switching controller switches the input source after the communication setup unit sets up the communication path; and an activation unit switching the image display apparatus from the standby state to an ON state when the standby state determining unit determines that the image display apparatus is in the standby state. 
         [0016]    According to this configuration, when the image display apparatus is in the standby state after the communication path is set up between the image signal supply apparatus and the image display apparatus, the image display apparatus is automatically changed to the ON state. Accordingly, it is possible to display the image acquired by the image signal supply apparatus on the image display apparatus simply and satisfactorily. 
         [0017]    According to another aspect of the invention, there is provided an image display apparatus displaying an image based on an image signal supplied from an image signal supply apparatus, including: an input source switching unit switching an input source of the image displayed by the image display unit; a communication setup unit setting up a communication due to the USB interface and a switching controller controlling the input source switching unit to switch the input source to the image signal supply apparatus in response to the notification that the communication setup unit sets up the communication. 
         [0018]    According to this configuration, when a communication path is set up between the image signal supply apparatus and the image display apparatus, the switching controller automatically switches the input source to the image signal supply apparatus. Accordingly, similarly to the image display system, a user can simply display an image acquired by the image signal supply apparatus on the image display apparatus, only by connecting the image signal supply apparatus to the image display apparatus. 
         [0019]    In another image display apparatus, the elements of the image display system may be added to the above-mentioned image display apparatus. 
         [0020]    The invention can be modified in various forms and can be embodied in the forms of a method for embodying the units of the image signal supply apparatus or the image display apparatus, a computer program for embodying the units, a recording medium having recorded thereon the computer program, and data signals embodied by carrier waves including the computer program. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
           [0022]      FIG. 1  is a diagram schematically illustrating a configuration of a projector system according to an embodiment of the invention. 
           [0023]      FIG. 2  is a diagram illustrating an internal configuration of a projector and a document camera. 
           [0024]      FIG. 3  is a flowchart illustrating a connecting process performed by controllers of the projector and the document camera. 
           [0025]      FIG. 4  is a diagram illustrating the internal configuration of a projection unit of the projector. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0026]    Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings. 
       1. Hardware Configuration 
       [0027]      FIG. 1  is a diagram schematically illustrating a projector system according to an embodiment of the invention. As shown in the drawing, the projector system  100  includes a projector  10  and four image input apparatuses connected to the projector  10 , such as a document camera  50 , a personal computer  90 , a video tape recorder (VTR)  91 , and a DVD player  92 . These image input apparatuses provide input sources of images to the projector  10 . Here, the image may be any of a still image and a moving image (that is, video). The document camera  50  acquires an image. The projector  10  selects a desired input source from the input sources and displays (projects) an image on a screen SC on the basis of the selected input source. 
         [0028]    The document camera  50  includes a base member  52 , a mounting plane  54 , an arm  56 , a camera head  58 , and an operation panel  60 . The mounting plane  54  is disposed on the base member  52  and a subject T such as a sheet of paper having characters or figures drawn thereon and a stereoscopic object is mounted thereon. The arm  56  holds the camera head  58 . The camera head  58  includes a lens, an LED, and a photoelectric conversion device such as a CCD and takes an image of the subject T mounted on the mounting plane  54 . The operation panel  60  includes plural buttons (button type switches) and allows a user to input an operating instruction to the document camera  50 . 
         [0029]    The arm  56  may extend upward from the base member  52  and then fixed, or may foldably rotate toward the base member  52 . By constructing the arm so as to be foldable, the document camera  50  can be compactly arranged. At the time of use, the folding of the arm  56  is released to unfold the arm. 
         [0030]    The document camera  50  having the above-mentioned configuration takes an image of the subject T mounted on the mounting plane  54  and outputs an image signal indicating the taken image to the projector  10 . The projector  10  and the document camera  50  are USB-connected to each other with a USB cable  62 . That is, the projector  10  and the document camera  50  are connected to each other directly via the USB interfaces. 
         [0031]      FIG. 2  is a diagram illustrating the internal configuration of the projector  10  and the document camera  50 . As shown in the drawing, the projector  10  includes a controller  20 , a storage unit  22 , an operation unit  24 , a USB interface unit  26 , an input interface unit  28 , an input source switching unit  30 , an image processor  32 , and a projection unit  34 . Reference numeral  36  represents a bus and connects the controller  20  to the units  22  to  32  other than the projection unit  34 . 
         [0032]    The controller  20  is constructed by a CPU or the like and operates in accordance with computer programs stored in the storage unit  22  to control the units  22  to  32 . The storage unit  22  stores image data or various computer programs. A known USB module, a USB video class driver, an image display program, and a program for a connecting process to be described later are stored as the computer programs. 
         [0033]    The operation unit  24  serves to input an operation instruction from the user to the projector  10  and includes an operation panel (not shown) and a remote controller receiver (not shown). The operation panel and the remote controller are provided with an input source switching button (not shown) for switching an input source of an image to be displayed by the projector  10 . 
         [0034]    The USB interface unit  26  is an interface used to transmit and receive control data or image data to and from an external device on the basis of a USB (Universal Serial Bus) standard. In this embodiment, the document camera  50  is connected to the USB interface unit  26 . 
         [0035]    The input interface unit  28  is an interface used to transmit and receive control data and image data to and from an external device other than a USB, and includes an RGB interface, a video interface, and an S-video interface. The RGB interface is connected to the personal computer  90 , the video interface is connected to the VTR  91 , and the S-video interface is connected to the DVD player  92 . 
         [0036]    The input source switching unit  30  switches the input source of the image to be displayed by the projector  10  by selecting one interface out of the USB interface unit  26  and the interfaces included in the input interface unit  28 . 
         [0037]    The image processor  32  generates display image data for image display on the basis of the image data or video data input from the interface selected by the input source switching unit  30 . As shown in  FIG. 4 , the projection unit  34  includes a light source  342 , light modulators  344  ( 344 R,  344 G, and  344 B), a projection lens  346 , a lighting optical system  341 , a color separating optical system  343 , a relay optical system  345 , and a synthesis optical system  347 . The projector  10  according to this embodiment includes a transmissive liquid crystal panel as the light modulators  344 . White light emitted from the light source  342  is separated into a beam, a green beam, and a blue beam while passing through the lighting optical system  341 , the color separating optical system  343 , and the relay optical system  345 , and the separated beams are modulated by the light modulators  344  on the basis of the display image data generated by the image processor  32  and are incident on the synthesis optical system  347 . The color image beams modulated by the light modulators  344  are synthesized by the synthesis optical system  347  and the synthesized image light is projected from the projection lens  346 . The synthesis optical system  347  can be constructed by a dichroic prism or the like. 
         [0038]    The document camera  50  includes a controller  70 , a storage unit  72 , an operation unit  74 , a USB interface unit  76 , a lighting unit  78 , a lighting controller  80 , an imaging unit  82 , an image processor  84 , and a resolution switching unit  86 . Reference numeral  88  represents a bus and connects the controller  70  to the units  72  to  76 ,  80 ,  84 , and  86  other than the lighting unit  78  and the imaging unit  82 . 
         [0039]    The controller  70  is constructed by a CPU or a DSP, and operates in accordance with computer programs stored in the storage unit  72  so as to control the units  70  to  86  included in the document camera  50 . The storage unit  72  stores image data or various computer programs. A known USB module, a USB class driver, and a program for a connecting process to be described later are stored as the computer programs. 
         [0040]    The operation unit  74  serves to input an operation instruction from a user to the document camera and includes an operation panel  60  (see  FIG. 1 ) disposed in the document camera  50 . 
         [0041]    The USB interface unit  76  serves to transmit and receive control data or image data to and from an external device on the basis of the USB standard. In this embodiment, the USB interface unit  76  is connected to the USB interface unit  26  of the projector  10 . Both USB interface units  26  and  76  correspond to the “USB interface” described in the claims. 
         [0042]    The lighting unit  78  includes a light source such as an LED emitting light to the subject T. The lighting controller  80  controls the turning-on and turning-off of the lighting unit  78 . The imaging unit  82  includes a photoelectric conversion device such as a CCD and a driving unit controlling an AE (automatic exposure)/AF (automatic focus) control operation. The imaging unit  82  is built in the camera head  58  (see  FIG. 1 ). The image processor  84  performs an image process such as white balancing on the image signal corresponding to the image taken by the imaging unit  82 . The resolution switching unit  86  switches the resolution of the image taken by the imaging unit  82  into a resolution requested by the projector  10 . The request of the projector  10  is sent from the projector  10  via the USB I/F unit  76 . 
         [0043]    The document camera  50  is supplied with power from the projector  10  via a USB interface unit  26 . 
         [0044]    The projector  10  and the document camera  50  having the above-mentioned configurations operate as follows to display an image of the subject T (see  FIG. 1 ). That is, when the operation unit  74  of the document camera  50  is operated, the controller  70  controls the lighting controller  80 , the image processor  84 , and the resolution switching unit  86  to take an image of the subject T mounted on the mounting plane  54  (see  FIG. 1 ), and temporarily stores the image signal (image data) acquired by imaging in the storage unit  72 . Thereafter, the controller  70  transmits the image signal stored in the storage unit  72  to the projector  10  via the USB I/F unit  76 . 
         [0045]    In the projector  10 , the controller  20  receives the image signal transmitted from the document camera  50  via the USB I/F unit  26  and controls the image processor  32  to generate the display image data on the basis of the received image signal. As a result, a projection beam modulated on the basis of the display image data is projected by the projection unit  34 . Finally, the image of the subject T is displayed on the screen SC (see  FIG. 1 ). 
         [0046]    As described above, the projector  10  includes various input sources in addition to the document camera  50 . When a user operates the input source switching button (not shown) included in the operation unit  24 , the controller  20  of the projector  10  activates the input source switching unit  30  to select one interface out of the USB interface unit  26  and the interfaces of the input interface unit  28 , whereby the input source of an image to be displayed by the projector  10  is switched. 
         [0047]    In this embodiment, when the document camera  50  is connected to the projector  10 , the projecting of the image taken by the document camera  50  using the projector is automatically started. The operations of the projector  10  and the document camera  50  when the projector  10  and the document camera  50  are connected to each other will be described in detail. 
       2. Software Configuration 
       [0048]      FIG. 3  is a flowchart illustrating a connecting process performed by the controllers  20  and  70  of the projector  10  and the document camera  50 . The right side of the drawing shows the connecting process in the controller  20  of the projector  10 , and the left side shows the connecting process in the controller  70  of the document camera  50 . 
         [0049]    When the flow of processes is started, the controllers (hereinafter, referred to as “projector controller” and “document camera controller”, respectively)  20  and  70  first perform a process of detecting the USB connection between the projector  10  and the document camera  50  (steps S 110  and S 210 ). In this process, it is detected that the USB interface unit  26  of the projector  10  and the USB interface unit  76  of the document camera  50  are connected using the USB cable  62 . Although not shown, the power supply from the projector  10  to the document camera  50  via the USB cable  62  is started by the connection. The controllers  20  and  70  wait for the detection of connection when the connection is not detected. 
         [0050]    The controllers  20  and  70  sets a configuration (steps S 120  and S 220 ) when the USB connection is detected. Specifically, the projector controller  20  requests a configuration descriptor from the document camera  50  and the document camera controller  70  returns the configuration descriptor to the projector  10  in response to the request. The projector controller  20  acquires the configuration descriptor transmitted from the document camera  50 . 
         [0051]    The descriptor includes the configuration descriptor indicating that the document camera  50  operates as an apparatus based on the USB standard. The configuration descriptor includes a list of functions for controlling the projector  10  by the functions of the document camera  50 , supported frame resolutions, supported frame formats (MJPEG/YUV), and types of color spaces (sRGB/BT.470-2(M)/BT.470-2(R,G)/SMPTE170M/SMPTE240M). As for the types of the color spaces, a color space used in the document camera  50  is determined and the determined color space is included in the configuration descriptor. 
         [0052]    The setting of configuration in steps S 120  and S 220  is performed actually in the process of enumeration started after the USB connection is detected. That is, the enumeration process based on the USB standard is actually performed, but only the setting of configuration which is an important element is described in the flowchart. 
         [0053]    The projector controller  20  loads a USB video class driver (step S 130 ) when the descriptor is normally acquired. Specifically, the USB video device class is detected on the basis of the device class information included in the descriptor and the USB video class driver is loaded. The following processes are performed using the loaded USB video class driver as needed. 
         [0054]    After performing the process of step S 130 , the projector controller  20  determines whether the projector  10  is in the standby state (step S 140 ), and turns on the projector  10  when it is determined that the projector is in the standby state (step S 150 ). After performing the process of step S 150 , the process of step S 160  is performed. When it is determined in step S 140  that the projector is not in the standby state, that is, that the projector is in the ON state, the process of step S 160  is performed. 
         [0055]    In step S 160 , the projector controller  20  determines whether the current input source of the projector  10 , that the current source, is the document camera  50 . Here, when it is determined that the current source is not the document camera  50 , a process of switching the input source of the projector  10  to the document camera  50  is performed (step S 170 ). Specifically, the input source switching unit  30  is activated to switch the input source of the image displayed by the projector  10  to the document camera  50 . The processes of steps S 160  and S 170  correspond to the “switching controller” in the claims. After the process of step S 170 , the process of step S 180  is performed. When it is determined in step S 160  that the current source is the document camera  50 , the process of step S 180  is performed. 
         [0056]    In step S 180 , the projector controller  20  performs a process of acquiring control parameters of the document camera  50 . In this process, various control parameters of the document camera  50  are requested and the various control parameters transmitted from the document camera  50  in response to the request are acquired. The control parameters include, for example, the set range values (Min/Max) of the functions (zoom, adjustment of contrast, adjustment of brightness, and the like) of the document camera  50  which can be controlled by the projector  10  and the current set values of the functions. The control parameters are used in the processes of the projector  10  not shown as needed. 
         [0057]    When the request for the control parameters is received from the projector controller  20 , the document camera controller  70  transmits the control parameters to the projector  10  in response to the request (step S 230 ). 
         [0058]    The projector controller  20  performs a stream negotiation process (step S 190 ) after performing the process of step S 180 . Here, the stream negotiation process is a process of setting the projector  10  on the basis of the configuration descriptor acquired in step S 120 . The document camera controller  70  similarly performs the stream negotiation process in cooperation with the projector controller  20  (step S 240 ). The processes of steps S 190  and S 240  serve to determine the conditions for transmitting a stream (image data), such as a frame resolution, a frame format, an interval, and a bandwidth. 
         [0059]    The document camera controller  70  transmits the stream (step S 250 ) under the conditions determined in step S 240  after performing the process of step S 240 . The projector controller  20  requests the document camera  50  to transmit a stream after performing the process of step S 190 , and receives the stream transmitted in step S 250  (step S 192 ). Thereafter, the projector controller  20  performs a process of correcting the colors of the image data which is the stream received in the step S 192  (step S 194 ) on the basis of the type of the color space included in the configuration descriptor acquired in step S 120 . That is, the projector controller  20  operates the image processor  32  to generate display image data by performing a color matching process so as to reproduce fully the target characteristic in the color gamut of the projector  10 , and sets the target characteristic in step S 194  on the basis of the type of the color space acquired in step S 180 . As a result, the display image data is corrected in color so as to be fully reproduced in the color gamut of the projector  10 . 
         [0060]    Subsequently, the projector controller  20  operates the projection unit  34  to project the display image data generated in step S 194  (step S 196 ). Thereafter, the projector controller  20  ends the connecting process. The document camera controller  70  ends the connecting process after performing the process of step S 250 . 
         [0061]    3. Operations and Advantages 
         [0062]    In the projector system  100  according to this embodiment having the above-mentioned configuration, when a communication path between the document camera  50  and the projector  10  is set up using the USB interface, the projector  10  automatically switches the input source to the document camera  50 . Thereafter, the stream is transmitted from the document camera  50  and the projector  10  receives the stream. Accordingly, a user can easily display the image taken by the document camera  50  by the use of the projector  10 , only by USB-connecting the projector  10  and the document camera  50 . 
         [0063]    In the projector system  100  according to this embodiment, when the projector  10  is in the standby state after the communication path between the document camera and the projector  10  is set up using the USB interface, the power source of the projector  10  is automatically changed to the ON state. The projector  10  automatically switches the input source to the document camera  50 . Accordingly, it is possible to display the image taken by the document camera  50  by the use of the projector  10  simply and satisfactorily. 
         [0064]    In this embodiment, since the projector  10  corrects the colors on the basis of the type of the color space included in the configuration descriptor acquired by the setting of configuration, the image taken by the document camera  50  is corrected in color so as to reproduce fully the image in the color gamut of the projector  10 . Accordingly, the color reproducibility in the projector  10  is excellent. 
       4. Modified Examples 
       [0065]    The invention is not limited to the above-mentioned embodiments or the modified examples thereof, but may be modified in various forms without departing from the spirit and scope of the invention. For example, the following modified examples can be employed. 
         [0066]    (1) Although it has been described in the above-mentioned embodiment that the control parameters of the document camera are acquired and transmitted (in steps S 180  and S 230 ) in the connecting process of the projector and the document camera  50  of the projector system  100 , the process of acquiring and transmitting the control parameters may not be performed. Although it has been described in the above-mentioned embodiment that the image color correcting process is performed in step S 194 , the image color correcting process may not be performed. The process of switching the input source to the document camera  50  in steps S 160  and S 170  may be performed just after step S 180  or just after step S 190 . 
         [0067]    (2) Although it has been described in the above-mentioned embodiment that the document camera  50  is used as the image signal supply apparatus, another image signal supply apparatus such as a web camera, a digital still camera, and a video camera having an imaging unit may be employed. 
         [0068]    (3) Although the projector  10  including the transmissive liquid crystal panels as the light modulators  344  has been exemplified as the image display apparatus in the above-mentioned embodiment, a reflective liquid crystal panel or a micro mirror device may be employed as the light modulators  344 . Although it has been described in the above-mentioned embodiment that the projector  10  employing three light modulators  344  is employed, the number of light modulators  344  is not limited to three. For example, a rotating color wheel may be disposed in the lighting optical system  341  and the color light beams may be generated in a time divisional manner using a single light modulator  344 . Four or more light modulators  344  may be employed. 
         [0069]    (4) Although the projector  10  projecting an image on an external screen SC is used as the image display apparatus in the above-mentioned embodiment, a projection television including a screen and a projector projecting an image to the back surface of the screen may be employed instead. Not limited to the projector, various image display apparatuses such as various direct-viewing flat panel display apparatuses may be employed. 
         [0070]    (5) it has been described in the above-mentioned embodiment that the projector  10  as the image display apparatus and the document camera  50  as the image signal supply apparatus are connected to each other by a USB cable  62 . Not limited to the wired connection, a wireless connection using a USB may be employed. 
         [0071]    (6) Some elements embodied by hardware in the above-mentioned embodiment may be replaced with software. On the contrary, some elements embodied by software may be replaced with hardware.