Abstract:
An information processing apparatus for communicating information with an information device. The information processing apparatus accesses virtual device image data representing an image of the information device, obtains status information representing a status of the information device from the information device through a bidirectional interface, and controls a display to display a virtual device image of the information device based on the accessed virtual device image data and the obtained status information. The virtual device image is a visual representation of the physical appearance of the information device in the status represented by the obtained status information.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an information processing apparatus for sending data to an output apparatus, such as a printer, which is connected through a bidirectional interface, and an output apparatus for receiving data from an information processing apparatus, such as a host computer, which is connected through a bidirectional interface, and performing output processing. 
     2. Related Background Art 
     Recently, a recording apparatus or a recording system capable of executing processing of the above sort is constructed by a host computer and a printer which is connected to the host computer through an interface (e.g., a Centronics interface). The recording apparatus or the recording system analyzes output information supplied from the host computer and develops bit-map data as output data of, e.g., a laser beam printer. The apparatus or the system then scan-exposes a photosensitive drum with a laser beam modulated on the basis of this developed data, thereby performing image recording. 
     In the case of a printer with an emulation function, a plurality of printer control language systems can be processed; the printer can execute printing while switching between an emulation mode and a native mode in accordance with applications that a user executes. The printer of this type has switches for switching the printer control languages and card slots for giving switching designation. 
     In addition, as the printing control functions of a printer have been increased in number in recent years, operations of an operation panel of a printer main body have become complicated. Therefore, a so-called “setup utility” by which a host computer performs various settings of a printer connected to the host computer generally has set items appearing in the form of a menu on a display. 
     Such a “setup utility” allows a host computer to perform operations which are usually performed from an operation panel of a printer. In many cases, however, the host computer performs operations for selecting items one-sidedly for the printer, so the status of the printer is not reflected on the display in real time. In addition, a real-time display of a paper feed condition of the printer is often performed on only the panel of the printer main body. 
     Furthermore, if some error occurs in a printer located apart from a host computer, an operator operating the host computer moves to the installation location of the printer to perform a recovery operation for that error, checking an error code displaying on a display panel of a printer operating unit while referring to a manual, and executing a necessary error recovery operation. 
     As described above, when the environment of a printer system is constructed by a host computer and a printer connected to the host computer through a predetermined interface, an operator cannot visually understand the settings, status, and error recovery of the printer. This results in very poor operability due to heavy loads of a printer environment setting operation and an error recovery operation on the operator. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to solve the above problems, and has as its object to provide an information processing apparatus and an output apparatus, in which the setting statuses of a printer connected and a virtually displayed printer are monitored and set to correspond to each other, operation designation for the printer can be realized by operation designation on the virtual printer by simulating the printing status and the printer panel display status of the printer on the virtual printer, and the status of a printing sequence of the printer can be visually checked on the virtual printer. 
     In order to achieve the above object of the present invention, there is provided an information processing apparatus comprising acquiring means for acquiring information from a printer connected through a bidirectional interface, and control means for controlling a display status of a virtual printer, which is displayed on a display screen and represents the printer, on the basis of the information acquired by the acquiring means. 
     In order to achieve the above object of the present invention, there is provided an output apparatus comprising setting means for setting an operating environment, and changing means for changing operating environment information set by the setting means on the basis of information acquired from an information processing apparatus connected through a bidirectional interface. 
     As described above, the operating environmental status information of a printer connected to a host computer via a bidirectional interface is acquired, and the simulated operation display status of a virtual printer displayed on the display screen of the host computer is controlled on the basis of the acquired operating environmental status information. In addition, designation information for the virtual printer is acquired from the host computer, and the operating environmental status of the printer is set to correspond to that of the virtual printer on the basis of the acquired designation information. Therefore, the connected printer can be displayed as a visual cubic image on the screen of the host computer by means of the virtual printer. It is also possible to display the status and settings of the printer on the virtual printer and reflect the settings of the virtual printer on the connected printer. 
     Furthermore, the panel setting status information of a printer connected to a host computer through a bidirectional interface is acquired, and the simulated operation display status of a virtual panel displayed on the display screen of the host computer is controlled on the basis of the acquired panel setting status information. The designation information for the virtual panel is also acquired from the host computer, and the panel setting status of the printer is set to correspond to that of the virtual panel on the basis of the acquired designation information. This makes it possible to display the panel status and settings of the printer on the virtual panel and reflect the settings of the virtual panel on the panel of the printer. 
     A user, therefore, can activate the panel simulation or the setup utility of the printer by a simple operation of designating a desired portion of the printer virtually displayed on the screen of the host computer. This enables the user to confirm the printer status and perform environmental setting of the printer without making any mistakes while visually monitoring the printer virtually displayed on the host computer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view showing the arrangement of a first recording apparatus to which the present invention is applicable; 
     FIG. 2 is a perspective view showing the outer appearance of a second recording apparatus to which the present invention is applicable; 
     FIG. 3 is a block diagram for explaining the control system of the second recording apparatus shown in FIG. 2; 
     FIG. 4 is a block diagram for explaining the arrangement of a printer control system according to one embodiment of the present invention; 
     FIG. 5 is a flow chart showing a virtual printer display sequence in the printer control system according to the present invention; 
     FIG. 6 is a view showing a virtual printer display transition status in the printer control system according to the present invention; 
     FIG. 7 is a view showing a virtual printer display transition status in the printer control system according to the present invention; 
     FIG. 8 is a view showing a virtual printer display transition status in the printer control system according to the present invention; 
     FIG. 9 is a view showing a virtual printer display transition status in the printer control system according to the present invention; 
     FIG. 10 is a flow chart showing a virtual panel simulation sequence shown in FIG. 5; 
     FIG. 11 is a flow chart showing a printer panel locking sequence shown in FIG. 5; 
     FIG. 12 is a flow chart showing another printer panel locking sequence different from that shown in FIG. 5; 
     FIG. 13 is a flow chart showing a power switch (P/S) simulation sequence shown in FIG. 5; 
     FIG. 14 is a flow chart showing an attached card simulation sequence shown in FIG. 5; 
     FIG. 15 is a flow chart showing an interface simulation sequence shown in FIG. 5; 
     FIG. 16 is a flow chart showing a paper feed cassette simulation sequence shown in FIG. 5; 
     FIG. 17 is a flow chart showing a paper feed tray simulation sequence shown in FIG. 5; 
     FIG. 18 is a flow chart showing an option slot simulation sequence shown in FIG. 5; 
     FIG. 19 is a flow chart showing a paper delivery tray simulation sequence shown in FIG. 5; and 
     FIG. 20 is a view showing contents in a cross section display mode of a virtual printer in the printer control system according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Before an explanation of the arrangement of this embodiment, the arrangements of a laser beam printer and an ink jet printer suitable for this embodiment will be described below with reference to FIGS. 1 to  3 . Note that a printer to which this embodiment is applied is not limited to the laser beam printer and the ink jet printer but may be a printer of another printing system. 
     FIG. 1 is a sectional view showing the arrangement of a first recording apparatus, for example, a laser beam printer (LBP), to which the present invention is applicable. 
     Referring to FIG. 1, an LBP main body  1500  receives and stores print information (e.g., character codes), form information, or macro instructions supplied from an externally connected host computer. The LBP main body  1500  forms character patterns or form patterns corresponding to the input information and forms images on recording paper as a recording medium. The LBP main body  1500  includes an operation panel  1501 , on which switches and LED indicators for operations are arranged, and a printer control unit  1000  for controlling the overall LBP main body  1500  and analyzing character information and the like supplied from the host computer. The printer control unit  1000  primarily converts character information into a video signal with the corresponding character pattern and applies the signal to a laser driver  1502 . The laser driver  1502  is a circuit for driving a semiconductor laser  1503 ; the laser driver  1502  switches on and off a laser beam  1504  emitted from the semiconductor laser  1503  in accordance with the input video signal. The laser beam  1504  scan-exposes an electrostatic drum  1506  while being oscillated sideways by a rotary polygon mirror  1505 . As a result, an electrostatic latent image of the character pattern is formed on the electrostatic drum  1506 . This latent image is developed by a developing unit  1507  arranged around the electrostatic drum  1506  and transferred onto recording paper. Cut sheets are used as the recording paper, and these cut sheets are housed in a paper cassette  1508  attached to the LBP main body  1500 . The cut sheets are fed into the printer and supplied to the electrostatic drum  1506  by a paper supply roller  1509  and paper feed rollers  1510  and  1511 . 
     FIG. 2 is a perspective view showing the outer appearance of a second recording apparatus, for example, an ink jet recording apparatus (IJRA), to which the present invention is applicable. 
     Referring to FIG. 2, a carriage HC engaging with a spiral groove  5004  of a lead screw  5005  which is rotated in association with the forward and backward rotations of a drive motor  5013  via driving force transmission gears  5011  and  5009  has a pin (not shown) and is therefore reciprocated in directions indicated by arrows a and b. An ink jet cartridge IJC is mounted on the carriage HC. A paper holding plate  5002  urges paper against a platen  5000  over the full width in the carriage moving direction. Photocouplers  5007  and  5008  function as home position detecting means for checking the presence of a lever  5006  of the carriage in this area and performing switching between the rotational directions of the motor  5013 . A support member  5016  supports a cap member  5022  for capping the entire surface of a recording head, and a sucking means  5015  for sucking the interior of the cap to perform suction-recovery for the recording head through an opening  5023  inside the cap. A cleaning blade  5017  can be moved forward and backward by a member  5019 . A main body support plate  5018  supports the members  5017  and  5019 . A lever  5012  for starting suction of the suction-recovery moves in association with the movement of a cam  5020  which engages with the carriage, controlling the driving force from the drive motor through a known transmitting means, such as clutch switching. 
     The apparatus is arranged such that capping, cleaning, and suction-recovery can be performed at their respective positions by the action of the lead screw  5005  when the carriage moves to an area on the home position side; that is, a desired operation need only be performed at a timing known to those skilled in the art. 
     FIG. 3 is a block diagram for explaining the control system of the second recording apparatus shown in FIG.  2 . 
     Referring to FIG. 3, this control system includes an interface  1700  for applying recording signals, an MPU  1701 , a program ROM  1702  for storing, e.g., control programs to be executed by the MPU  1701 , and a DRAM  1703  for storing various data (such as the recording signals and recording data to be supplied to a head). A gate array  1704  controls the supply of the recording data to a recording head  1708  and also controls the transfer of data between the interface  1700 , the MPU  1701 , and the DRAM  1703 . A carriage motor  1710  carries the recording head  1708 , and a paper feed motor  1709  feeds recording paper. A head driver  1705  drives the recording head, a motor driver  1706  drives the paper feed motor  1709 , and a motor driver  1707  drives the carriage motor  1710 . 
     In the recording apparatus with the above arrangement, when a recording signal is applied from a host computer  100  (to be described later) through the interface  1700 , this recording signal is converted into recording data for printing by the gate array  1704  and the MPU  1701 . Then the motor drivers  1706  and  1707  are driven, and the recording head is also driven by the recording data supplied to the head driver  1705 , thereby executing printing. 
     The MPU  1701  can perform communications with the host computer  100  (to be described later) through the interface  1700 ; the MPU  1701  can inform the host computer  100  (to be described later) of memory information related to the DRAM  1703  and resource data (including operating environmental status information and panel setting status information to be described later). 
     [Embodiment] 
     FIG. 4 is a block diagram for explaining the arrangement of a printer control system according to one embodiment of the present invention. The first embodiment will be described below by taking the laser beam printer (FIG. 1) as an example. Note that the present invention can be applied to any of a single apparatus, a system comprising a plurality of apparatuses, and a system in which processing is executed via a network, such as a LAN, provided that the functions of the present invention are executed. 
     Referring to FIG. 4, the host computer  100  has a CPU  1  for executing processing for documents consisting of graphics, images, characters, tables (including spreadsheets), and the like on the basis of document processing programs stored in a ROM  2 . The CPU  1  systematically controls individual devices connected to a system bus  4 . 
     The ROM  2  stores the control programs of the CPU  1  shown in the flow charts of FIG.  5  and the like. A RAM  3  serves as a main memory and a work area for the CPU  1 . A keyboard controller (KBC)  5  controls key inputs from a keyboard  9 . A CRT controller (CRTC)  6  controls a display on a CRT display (CRT)  10 . A disk controller (DKC)  7  controls access to a hard disk (HD)  11  and a floppy disk (FD)  12  which store boot programs, various applications, font data, user files, edit files, and virtual printer image data (to be described later). A printer controller (PRTC)  8  is connected to the printer  1500  through a predetermined bidirectional interface (interface)  13  and executes processing for controlling communications with the printer  1500 . Interface circuits  8   a  and  18   a  control command communication processing and recording information processing executed between the printer  1500  and the host computer  100  through the interface  13 . 
     The CPU  1  executes processing for developing (rasterizing) an outline font into a display information RAM set in the RAM  3 , allowing WYSIWYG on the CRT  10 . The CPU  1  also opens various registered windows on the basis of commands designated by a mouse cursor (not shown) or the like on the CRT  10 , executing various tasks of data processing. In addition, the CPU  1  manages the virtual printer image data or the virtual panel image data stored in the hard disk  11 . That is, the CPU  1  controls the setting of a printer mode on the basis of designation by a pointing device (not shown) for the virtual printer displayed on the CRT  10  and displays the setting status on the virtual display unit. The CPU  1  then transfers the mode setting information to the printer  1500 , and the CPU  14  controls the setting of the display status on the operation panel  1501  so that the printer setting statuses of the actual and virtual printers correspond to each other. The setting information (stored in the RAM  16 ) on the operation panel  1501  is also informed to the host computer  100 . The CPU  1  controls the display of the virtual printer so that the display status of the virtual printer also corresponds to the mode setting status of the printer. 
     In the printer  1500 , a printer CPU  14  systematically controls access to various devices connected to a system bus  17  on the basis of control programs and the like (indicated by the flow chart shown in FIG. 11) stored in a ROM  15  and outputs image signals as print data to a printer mechanism (printer engine)  20  connected through a printer interface  19 . The memory capacity of a RAM  16  can be extended by an optional RAM connected to an expansion port. Note that the RAM  16  stores operating environmental status information and panel set status information (to be described later), and the information is sequentially updated by the CPU  14 . 
     The printer control system also includes at least one card slot (not shown) so that optional font cards and cards (emulation cards) storing programs for interpreting printer control languages of different language systems can be connected and used, in addition to internally stored fonts. Note that the above-mentioned panel setting status information and the like may be stored in an NVRAM (not shown). 
     In the printer control system with the above arrangement, when the CPU  1  acquires operating environmental status information from the RAM  16  in the printer connected to the host computer  100  through the bidirectional interface  13 , the CPU  1  controls the simulated operation display status of the virtual printer displayed on the display screen (CRT  10 ) of the host computer  100 . In addition, when the CPU  14  acquires designation information for the virtual printer from the host computer  100 , the CPU  14  sets the matching between the operating environmental statuses of the printer and the virtual printer on the basis of the acquired designation information. Therefore, the connected printer can be displayed as a visual cubic image on the screen of the host computer by means of the virtual printer. It is also possible to display the status and settings of the printer on the virtual printer and reflect the settings of the virtual printer on the printer. 
     The virtual printer control operation will be described below with reference to the flow chart shown in FIG.  5  and the virtual display statuses shown in FIGS. 6 to  9 . 
     FIG. 5 is a flow chart showing a virtual printer display sequence performed by the CPU  1  in the printer control system according to the present invention, in which processing steps ( 1 ) to ( 15 ) are illustrated. 
     In step ( 1 ), the CPU  1  checks whether a display of the virtual printer is requested by designation by the pointing device (not shown) or the keyboard  9  of the host computer  100 . If YES in step ( 1 ), the flow advances to step ( 2 ), and, as shown in FIG. 6, the CPU  1  displays a 3D image (three-dimensional image) of the virtual printer corresponding to the connected printer  1500  in a window W 1  on the CRT  10 . 
     Subsequently, in step ( 3 ), the CPU  1  checks whether a viewpoint and scroll bars SB 1  and SB 2  are designated by a cursor K through the use of the pointing device (not shown). If YES in step ( 3 ), the CPU  1  rotates the cubic image of the virtual printer in the directions designated by the scroll bars SB 1  and SB 2  in step ( 6 ), and the flow returns to step ( 2 ). 
     In step ( 4 ), the CPU  1  checks whether any of desired positions P 1  to P 6  in virtual printer images PIM 1  to PIM 3  shown in FIGS. 6 to  8  is designated by the cursor. If NO in step ( 4 ), the CPU  1  executes other corresponding processes in step ( 5 ). If YES in step ( 4 ), the CPU  1  determines the position designated by the cursor K, activating one of simulators (to be described in detail later) corresponding to the designated position (steps ( 8 ) to ( 15 )), and ending the processing. 
     As described above, the operating environmental status information (stored in the RAM  16 ) of the printer  1500  connected to the host computer  100  through the bidirectional interface (e.g., RS232C)  13  is acquired, and the simulated operation display status of the virtual printer displayed on the display screen of the host computer  100  is controlled on the basis of the acquired operating environmental status information. In addition, the designation information for the virtual printer (virtual printer images PIM 1  to PIM 3 ) is acquired from the host computer  100 , and the operating environmental status of the printer  1500  is set to correspond to that of the virtual printer on the basis of the acquired designation information. Therefore, the printer  1500  connected can be displayed as a visual cubic image on the screen of the host computer  100  by means of the virtual printer. It is also possible to display the status and settings of the printer  1500  on the virtual printer and reflect the settings of the virtual printer on the printer  1500 . 
     Furthermore, the panel setting status information stored in the RAM  16  of the printer  1500  connected to the host computer  100  through the bidirectional interface  13  is acquired, and the simulated operation display status of the virtual panel (the panel image PI shown in FIG. 9) displayed on the display screen of the host computer is controlled on the basis of the acquired panel setting status information. The designation information for the virtual panel is also acquired from the host computer  100 , and the setting status of the operation panel  1501  of the printer  1500  is set to correspond to that of the virtual panel on the basis of the acquired designation information. This makes it possible to display the panel status and the panel settings of the printer  1500  on the virtual panel and reflect the settings of the virtual panel on the panel of the printer  1500 . 
     FIG. 10 is a flow chart showing a virtual panel simulation sequence shown in FIG. 5 that is performed by the CPU  1 , in which processing steps ( 1 ) to ( 10 ) are illustrated. 
     First, in step ( 1 ), the CPU  1  of the host computer  100  waits until current panel setting status information (stored in the RAM  16 ) set in the printer  1500  is transferred. In step ( 2 ), in accordance with the input panel setting data, the CPU  1  displays the virtual panel by using the virtual panel image PI such that the display on a display D and indications of indicators L 1  to L 5  shown in FIG. 9 correspond to those of the operation panel  1501  of the printer  1500 . 
     Subsequently, in step ( 3 ), the CPU  1  checks whether key-lock for disabling depression of all keys or keys except that for releasing errors of the printer  1500  is designated. If YES in step ( 3 ), the CPU  1  executes the routine of a printer panel locking process (to be described later) in step ( 10 ) and ends the processing. 
     If No in step ( 3 ), the CPU  1  checks in step ( 4 ) whether any of virtual keys KEY 1  to KEY 8  on the virtual panel image IP is designated. If NO in step ( 4 ), the flow returns to step ( 2 ). If YES in step ( 4 ), the CPU  1  displays items corresponding to the virtual keys KEY 1  to KEY 8  in a window or pulldown in step ( 5 ). In step ( 6 ), the CPU  1  updates the virtual panel mode display currently being set in accordance with the selected item. In step ( 7 ), the CPU  1  transfers the key setting status file corresponding to the settings of the keys KEY 1  to KEY 8  to the printer  1500 . The CPU  1  then updates the setting status of the operation panel  1501  of the printer  1500  in step ( 8 ) and waits until the display status of the operation panel  1501  of the  1500  is updated in step ( 9 ), thereby ending the processing. This enables the display status of the operation panel  1501  of the printer  1500  to correspond to that of the virtual panel in accordance with the key operations and the mode display on the virtual panel image PI. 
     As described above, since the display status of the virtual panel image IP on the CRT  10  of the host computer  100  changes in association with the operations on the operation panel  1501  of the printer  1500 , the operating environmental status of the printer  1500  can be easily confirmed on the screen of the host computer  100 . In addition, in operating the virtual keys KEY 1  to KEY 8  corresponding to the virtual panel image PI on the CRT  10  of the host computer  100 , an operator can perform the key operation while monitoring all items that can be set, and this key operation is reflected on the set result on the operation panel  1501  of the printer  1500 . Note that in transferring data between the host computer  100  and the printer  1500 , information may be exchanged between the host computer  100  and the printer  1500  whenever the key operation is performed. Furthermore, in this embodiment, the reaction (change in menu display or the like) for each key operation is simulated by the host computer  100 , and, after the setting is completed by the host computer  100 , the set contents are transferred to the printer  1500 . However, the processing for selecting and displaying set items may also be executed by receiving information from the printer  1500 . Consequently, a user can set the printer  1500  from the host computer  100  and can also check the environmental setting status of the printer  1500  without moving to the installation location of the printer. 
     FIG. 11 is a flow chart showing a printer panel locking sequence shown in FIG. 5 that is performed by the CPU  14 , in which processing steps ( 1 ) to ( 11 ) are illustrated. 
     First, in step ( 1 ), the CPU  14  of the printer  1500  checks whether some command is input from the host computer  100 . If NO in step ( 1 ), the CPU  14  checks in step ( 5 ) whether a flag for permitting inputs from the keys arranged on the operation panel  1501  of the printer  1500  is currently permissible. If NO in step ( 5 ), the flow returns to step ( 1 ). If YES in step ( 5 ), the CPU  14  waits until a key input is supplied from the keys arranged on the operation panel  1501  of the printer  1500 . If the key input is obtained in step ( 6 ), the CPU  14  executes a key input process in step ( 7 ), and the flow returns to step ( 1 ). 
     If YES in step ( 1 ), on the other hand, the CPU  14  checks in step ( 2 ) whether the input command is a command for permitting the panel operation on the operation panel  1501  of the printer  1500 . If YES in step ( 2 ), the CPU  14  sets the state “permissible” for the flag for permitting inputs from the keys arranged on the operation panel  1501  of the printer  1500  in step ( 3 ) and turns a panel lamp on in step ( 4 ), thereby ending the processing. 
     If NO in step ( 2 ), the CPU  14  checks in step ( 8 ) whether the input command is a command for inhibiting the panel operation on the operation panel  1501  of the printer  1500 . If NO in step ( 8 ), the CPU  14  executes other corresponding processes in step ( 11 ) and ends the processing. 
     If YES in step ( 8 ), the CPU  14  sets the state “inhibited” for a flag for inhibiting inputs from the keys arranged on the operation panel  1501  of the printer  1500  in step ( 9 ) and turns the panel lamp off in step ( 10 ), thereby ending the processing. 
     As described above, while the printer operating environment is being set from the virtual panel, the settings on the virtual panel are given priority by disabling the designation for the panel setting operation of the printer. Therefore, in a system in which the environment of the printer  1500  can be set from the setup utility, the panel simulation, or the like of the host computer  100 , the operation on the operation panel of the printer  1500  can be temporarily inhibited by a command from the host computer  100 . This effectively avoids an undesirable event in which another user carelessly changes the environmental settings of the printer  1500  in situations where the host computer and the printer  1500  are located apart from each other, i.e., where the printer functions as a so-called shared printer, thereby obtaining desired printing results. If, however, the panel operation inhibited state set in the printer  1500  continues for a long period of time, the function of the shared printer may be impaired. Therefore, as shown in FIG. 12, the system may be modified such that the inhibition time is managed by the counter function of the CPU  14 , and, if a predetermined inhibition release time has elapsed, operations of the keys of the printer  1500  are enabled. 
     FIG. 12 is a flow chart showing another printer panel locking sequence different from that shown in FIG. 5 that is performed by the CPU  14 , in which processing steps ( 1 ) to ( 15 ) are illustrated. 
     First, in step ( 1 ), the CPU  14  of the printer  1500  checks whether some command is input from the host computer  100 . If NO in step ( 1 ), the CPU  14  activates its internal counter in step ( 12 ) and checks in step ( 13 ) whether the value of the counter is equal to or larger than a count value which is set to release the panel operation inhibition. If NO in step ( 13 ), the flow advances to step ( 5 ) and the subsequent steps. If YES in step ( 13 ), the CPU  14  sets the state “permissible” for the flag for permitting inputs from the keys arranged on the operation panel  1501  of the printer  1500  in step ( 14 ) and turns the panel lamp on ( 15 ). 
     Subsequently, in step ( 5 ), the CPU  14  checks whether the flag for permitting inputs from the keys arranged on the operation panel  1501  of the printer  1500  is currently permissible. If NO in step ( 5 ), the flow returns to step ( 1 ). If YES in step ( 5 ), the CPU  14  waits until a key input is supplied from the keys arranged on the operation panel  1501  of the printer  1500  in step ( 6 ). If the key input is obtained in step ( 6 ), the CPU  14  executes a key input process in step ( 7 ), and the flow returns to step ( 1 ). 
     If YES in step ( 1 ), the CPU  14  checks in step ( 2 ) whether the input command is a command for permitting the panel operation on the operation panel  1501  of the printer  1500 . If YES in step ( 2 ), the CPU  14  sets the state “permissible” for the flag for permitting inputs from the keys arranged on the operation panel  1501  of the printer  1500  in step ( 3 ) and turns the panel lamp on in step ( 4 ), thereby ending the processing. 
     If NO in step ( 2 ), the CPU  14  checks in step ( 8 ) whether the input command is a command for inhibiting the panel operation on the operation panel  1501  of the printer  1500 . If NO in step ( 8 ), the CPU  14  executes other corresponding processes in step ( 11 ) and ends the processing. 
     If YES in step ( 8 ), the CPU  14  sets the state “inhibited” for the flag for inhibiting inputs from the keys arranged on the operation panel  1501  of the printer  1500  in step ( 9 ) and turns the panel lamp off in step ( 10 ), thereby ending the processing. 
     With the above arrangement, even when the key operation on the operation panel  1501  of the printer  1500  is disabled by the command designation from the host computer  100 , the key operation enable state can be automatically restored. Note that the control may be performed to enable the error release key operation on the operation panel  1501  of the printer  1500  if a paper feed jam or the like occurs during execution of the printer sequence by the printer mechanism  20  of the printer  1500 . 
     FIG. 13 is a flow chart showing a power source switch simulation sequence shown in FIG. 5 that is performed by the CPU  1  and the CPU  14 , in which processing steps ( 1 ) to ( 5 ) are illustrated. 
     This sequence is started when, for example, the position P 2  is designated by the pointing device (not shown) on the display screen shown in FIG.  6 . First, in step ( 1 ), the CPU  1  checks the ON/OFF state designated by the virtual switch. If ON is determined in step ( 1 ) and the printer is the laser beam printer shown in FIG. 1, power supply to H.V. is started and the printer mechanism  20  is warmed up in step ( 2 ). If the printer is the bubble jet printer as shown in FIG. 2, power supply to various drivers is started in order to activate the cleaning mechanism of the printer head. 
     Subsequently, when printing becomes possible in step ( 3 ), the CPU  14  transfers a printer status signal indicating a printer enable status to the host computer  100  in step ( 4 ) and ends the processing. 
     If OFF is determined in step ( 1 ), power supply to parts except a communication unit for performing communications with the host computer  100  is stopped, setting an apparent off-line status. 
     FIG. 14 is a flow chart showing an attached card simulation sequence shown in FIG. 5 that is performed by the CPU  1  and the CPU  14 , in which processing steps ( 1 ) to ( 9 ) are illustrated. 
     First, in step ( 1 ), the CPU  14  waits until card attachment data is acquired from the printer  1500 . In step ( 2 ), the CPU  14  analyzes the card attachment data acquired to determine the card type. After this determination, in step ( 3 ), the CPU  14  checks whether the card is attached to or detached from the printer  1500 . If YES in step ( 3 ), the CPU  14  waits until the card attachment data is again acquired in step ( 8 ). When the card attachment data is acquired, the CPU  1  updates the virtual card display status on the CRT  10  of the host computer  100  in step ( 9 ), and the flow returns to step ( 2 ). 
     If NO in step ( 3 ), the CPU  14  checks in step ( 4 ) whether the attached card is a font card (style font card for determining, e.g., the printed style or the Gothic type). If YES in step ( 4 ), the CPU  1  displays the type and contents of the font together with the virtual printer image PIM 1  in step ( 7 ) and ends the processing. 
     If NO in step ( 4 ), the CPU  14  checks in step ( 5 ) whether the attached card is a control card for, e.g., emulation. If NO in step ( 5 ), the flow returns to step ( 3 ). If YES in step ( 5 ), the CPU  1  displays the type and contents of the card together with the virtual printer image PIM 1  in step ( 6 ) and ends the processing. 
     FIG. 15 is a flow chart showing an interface simulation sequence shown in FIG. 5 that is performed by the CPU  1 , in which processing steps ( 1 ) and ( 2 ) are illustrated. 
     First, in step ( 1 ), the CPU  1  of the host computer  100  acquires interface status data from the printer  1500 . Subsequently, in step ( 2 ), the CPU  1  displays, e.g., the interface type, the communication protocol, and the buffer capacity allocated to that interface together with the printer image PIM 1  in step ( 2 ) and ends the processing. 
     FIG. 16 is a flow chart showing a paper feed cassette simulation sequence shown in FIG. 5 that is performed by the CPU  1 , in which processing steps ( 1 ) and ( 2 ) are illustrated. 
     First, in step ( 1 ), the CPU  1  of the host computer  100  acquires paper feed cassette status data from the printer  1500 . Subsequently, in step ( 2 ), the CPU displays the paper size and the number of remaining papers or paper sheets of the paper feed cassette which is enabled to perform paper feed, together with the virtual printer image PIM 1 , and ends the processing. If a plurality of paper feed cassettes can be stacked in a stack, the paper size and the number of remaining paper sheets of a paper feed cassette that is given priority for paper feed may be displayed together with the virtual printer image PIM 1 . 
     FIG. 17 is a flow chart showing a paper feed tray simulation sequence shown in FIG. 5 that is performed by the CPU  1 , in which processing steps ( 1 ) and ( 2 ) are illustrated. 
     First, in step ( 1 ), the CPU  1  of the host computer  100  acquires paper feed tray status data from the printer  1500 . Subsequently, in step ( 2 ), the CPU  1  displays the paper size and the number of remaining paper sheets of a paper feed tray which is enabled to perform paper feed, together with the virtual printer image PIM 1 , and ends the processing. 
     FIG. 18 is a flow chart showing an option slot simulation sequence shown in FIG. 5 that is performed by the CPU  1 , in which processing steps ( 1 ) and ( 2 ) are illustrated. 
     First, in step ( 1 ), the CPU  1  of the host computer  100  acquires paper feed tray status data from the printer  1500 . Subsequently, in step ( 2 ), the CPU  1  displays the contents of an optional ROM board and/or an optional RAM board attached to the option slot, together with the virtual printer image PIM 3 , in the message window MW as shown in FIG. 8, and ends the processing. 
     FIG. 19 is a flow chart showing a paper delivery tray simulation sequence shown in FIG. 5 that is performed by the CPU  1 , in which processing steps ( 1 ) to ( 11 ) are illustrated. 
     First, in step ( 1 ), the CPU  1  of the host computer  100  checks from printer status information acquired whether the printer  1500  is executing paper delivery. If NO in step ( 1 ), the CPU  1  checks whether the position P 6  corresponding to the paper delivery tray shown in FIG. 6 has been designated by the cursor K with the pointing device (not shown) for a predetermined time. If YES in step ( 2 ), the CPU  1  switches the 3-dimensional display of the virtual printer to a cross section display as shown in FIG. 20 in step ( 3 ), displaying paper feed paths PATH 1  to PATH 3 . If a paper feed jam occurs during the paper feed, the CPU  1  cause a corresponding lamp to flicker at the position of the jammed paper. Note that in this printer cross section display mode, the condition of paper being fed is displayed as graphics in real time. 
     Subsequently, in the same printer cross section display state, if the paper delivery unit is designated by the cursor in step ( 4 ), and, if a predetermined time has elapsed in this designation state in step ( 5 ), the CPU  1  releases the printer cross section display mode and acquires current printer status data of the printer  1500  in step ( 6 ). The CPU  1  then switches to the 3-dimensional display of the virtual printer in step ( 7 ) and ends the processing. Note that the switching between the printer cross section display mode and the virtual printer need not be executed by the designation described above but may be performed at any given timing by another designation on the screen or designation from the key board or by detecting the change in designation status of the printer  1500 . 
     If YES in step ( 1 ), the CPU  1  displays a paper deliver simulation on the CRT  10  of the host computer  100  in step ( 8 ). In this case, if the top page of virtual sheets of paper currently being delivered is designated by the cursor K with the pointing device (not shown), the CPU  1  displays the preview image of that page on the CRT  10  of the host computer  100  in step ( 10 ). The CPU  1  then waits until the paper delivery is ended in step ( 11 ), and, when the paper delivery is ended, ends the processing. 
     Although the printer  1500  and the host computer  100  are connected through an RS232C in the above embodiment, the present invention is, of course, applicable to any bidirectional interface regardless of whether the interface is of a wired or radio type. 
     In some cases, a printer that is additionally registered as a usable printer is present or the key shape or the key position of a printer is changed by changes in version or the like. Even in these situations, however, the virtual display processing can be realized for any such commercially available printer by registering or updating virtual printer image data or virtual panel image data from a floppy disk drive (not shown) connectable to the host computer  100  or from a network.