JP2008191405A - Image display device and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable even a user who does not have technical knowledge to easily and securely set a signal format of an output video signal matching an external display device in an image display device capable of outputting video signals of a plurality of signal formats. <P>SOLUTION: An image for operation explanation that requests a user to press an OK button when an image is correctly displayed on a television screen is displayed on a display unit provided to a main body, and encoded into a video signal of a temporarily set signal format, and the encoded video signal is output (steps S201 to S203). When the user presses a button other than the OK button, the processings are repeated while signal formats are changed in order (steps S204 to S206). Once the OK button is pressed, the current signal format is set to a following format (step S207). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display apparatus capable of outputting a video signal to an external display apparatus, and more particularly to an apparatus having a function of selectively outputting video signals of a plurality of signal formats.

  Some electronic devices such as photo printers and digital cameras are provided with relatively small display means such as a liquid crystal display for displaying images. In these devices, an external display device having a larger screen, For example, there is a user's request to display an image on a television receiver. In order to meet such a demand, for example, in the technology described in Patent Document 1, a video signal corresponding to a thumbnail image, a function selection image, or the like is output from an external output port of a stand-alone printer that is one of the electronic devices described above. The enlarged image is displayed on the external display device connected to the port.

Japanese Patent Application Laid-Open No. 2003-201557

  The signal format of the video signal to be input to the external display device is not completely standardized, and a plurality of incompatible types are used. For example, it is considered that a television receiver is often used as an external display device in a general home, but there are NTSC system, PAL system, SECAM system, etc. as signal formats of the television receiver. It is used properly by region.

  Many conventional apparatuses capable of outputting video signals in a plurality of signal formats are configured to allow a user to select and set a signal format in advance by using a switch or the like provided on an operation panel. However, such a setting method requires specialized technical knowledge from the user and cannot be said to be highly convenient for general users. In particular, in the case of a device characterized by portability, it may be used while changing the external display device in various ways, so that it is possible to more easily and reliably select and set a signal format suitable for the external display device. It is required to do so.

  The present invention has been made in view of the above problems, and in an image display device capable of outputting video signals in a plurality of types of signal formats, a signal of an output video signal adapted to an external display device even by a user having no specialized knowledge. An object of the present invention is to provide an image display device that can easily and reliably set a format and is excellent in user convenience.

  In order to achieve the above object, an image display device according to the present invention has a function of generating video signals conforming to a plurality of different signal formats, and the video signal conforming to one selected signal format is externally provided. Video signal output means for outputting to a display device; control means for designating the selection signal format for the video signal output means; display means for displaying an image; and accepting means for accepting an operation input from a user. The control means outputs the video signal corresponding to a predetermined test image from the video signal output means while sequentially switching the plurality of signal formats, and the test image is externally displayed to the user. An explanatory image that requests the receiving means to perform a predetermined operation input when displayed on the apparatus. Is displayed on the display means, and the signal format of the video signal output from the video signal output means when the user inputs the predetermined operation input to the receiving means is determined as the selection signal format. It is characterized by executing a decision process.

  In order to achieve the above object, a method for controlling an image display apparatus according to the present invention provides a plurality of types of signals from video signal output means having a function of generating video signals conforming to a plurality of different signal formats. The video signal corresponding to a predetermined test image is output to an external display device while switching the format in order, and the receiving means displays the image when the test image is displayed on the external display device. An explanatory image for requesting the user to perform a predetermined operation input is displayed, and the video signal output from the video signal output means when the user inputs the predetermined operation input to the receiving means. The signal format is determined as the selection signal format, and the signal format of the video signal output from the video signal output means thereafter. The Matto, is characterized by setting the determined the selection signal format.

  In the invention configured as described above, the video signal is output to the external display device while sequentially switching the signal format. Therefore, the correct image is displayed on the external display device during a period in which the signal format that is not suitable for the device is used. While it is not displayed, the image is displayed normally during the period in which the compatible signal format is used. Then, by allowing the user to perform a predetermined operation input when a normal image is displayed, it is possible to know which signal format is suitable for the external display device. At this time, by displaying an image for explaining the operation on the display means provided in the image display apparatus body, the user can select and set the signal format without hesitation in the operation. As described above, according to the present invention, even a user who does not have specialized knowledge can easily and surely set the signal format of the output video signal suitable for the external display device, and the image has excellent user convenience. A display device can be configured.

  Here, for example, the signal format of the video signal output from the video signal output means can be automatically switched at a predetermined cycle. In this way, a normal image can be displayed on the external display device for a certain period without any operation by the user. Therefore, even if the correct image is not displayed initially due to incompatibility of the signal format, the correct image is temporarily displayed after a while, so that the user can easily understand that there is no abnormality in the device or incorrect connection. . In this case, it is desirable to cyclically and repeatedly switch the output signal format.

  Further, for example, the signal format of the video signal output from the video signal output means may be switched according to a user switching operation. In this way, since the signal format can be switched while allowing the user to confirm the screen display, the signal format selection and setting can be surely performed without panicking a person unfamiliar with the operation of the device.

  Further, the display contents of the test image and the explanatory image may be the same. In this way, the user can easily determine whether the image is correct by comparing the image displayed on the external display device with the image displayed on the main body side. Further, by displaying the explanatory image on the external display device, the user can more easily grasp the operation to be performed by the user.

  The signal format switching order in the format determination process may be changed according to the result of the format determination process executed in the past. In this way, the signal format switching order is not uniform, but can be changed according to the past setting contents, so that the user can perform the setting in a shorter time. For example, in the first format determination process, the signal format is switched in a predetermined order. When the format determination process is executed again after being determined, the previously selected signal format is changed. If it is used first, the probability that a correct image is displayed from the first signal output is increased.

  The video signal output means further comprises detection means for detecting whether or not an external display device is connected, and when the detection means detects that the external display device is newly connected, The determination process may be executed. The selection of the signal format need not always be performed. Basically, once the selection setting is performed, the selection result may be maintained thereafter. However, if it is confirmed that the external display device is newly connected, the format determination process is executed again to avoid a situation in which the image is not correctly displayed on the new external display device. Can do.

  In this case, if the user performs a predetermined prohibition setting operation after determining the selection signal format by the format determination process, the subsequent execution of the format determination process is prohibited regardless of the detection result of the detection means. You may do it. In this way, it is possible to prevent the format determination process from starting until unnecessary. Even in this case, it is desirable to take measures for canceling the prohibition of execution of the format determination process.

  In addition, when the display unit is capable of displaying the explanation image in one language selected by the user among the plurality of explanation images described in characters of different languages, The signal format switching order in the format determination process may be changed according to the language selection by the user. This is because the region where the apparatus is used can be estimated to some extent from the language setting result by the user, and therefore a certain degree of estimation can be established for the signal format used. By doing so, the user can select an appropriate signal format in a shorter time with less effort.

  FIG. 1 is a perspective view showing a photo printer which is an embodiment of the image display apparatus of the present invention. FIG. 2 is a diagram showing an outline of the internal configuration of the photo printer. In this photo printer 10, a printing mechanism 50 (see FIG. 2) is built in the printer main body 12, and in response to an operation command from a controller 70 (see FIG. 2) that controls the entire photo printer 10. Printing on the paper P is executed. Then, the printed paper is discharged to the front surface of the printer main body 12.

  As shown in FIG. 1, a front door 14 is attached to the front surface of the printer main body 12 so as to be freely opened and closed. The front door 14 is a lid for opening and closing the front surface of the printer main body 12. In the open state, it functions as a paper discharge tray for receiving the paper P discharged from the print mechanism 50. In addition, various memory card slots 16 provided on the front surface of the printer main body 12 can be used by the user. That is, in this state, the user can insert the memory card M storing the image file to be printed into the memory card slot 16. The external medium for storing the image file data is not limited to the memory card, but may be another one such as a USB memory or a disk medium. Further, an electronic device such as a digital camera or a mobile phone that stores images may be connected to the photo printer 10 by communication using a cable or infrared rays so as to function as an external medium.

  An operation panel 20 is provided on the upper surface of the printer main body 12, and a cover 30 is attached to an inner side of the upper surface of the printer main body 12 so as to be freely opened and closed. The cover 30 is a resin plate formed in a size that can cover the upper surface of the printer main body 12, and exposes the surface of the operation panel 20 to the outside in the open state (see FIG. 1). On the other hand, when the cover 30 is closed, the entire operation panel 20 is covered.

  The operation panel 20 includes a display unit 22 configured by, for example, an LCD display for displaying characters, graphics, symbols, and the like, and a button group 24 arranged around the display unit 22. As shown in FIG. 2, the button group 24 includes a power button 24a for turning on / off the power, a menu button 24b for calling the main menu screen, canceling the operation in the middle, and interrupting the printing on the paper P in the middle. A cancel button 24c for printing, a print button 24d for instructing execution of printing on the paper P, a save button 24e for saving an edited image in the memory card M inserted in the memory card slot 16, a display unit Each of the up / down / left / right arrow buttons 24f to 24i operated when selecting a desired option from the plurality of options displayed on the screen 22 or moving the cursor, and the up / down / left / right arrow buttons 24f to 24i. An OK button for instructing that the option selected by the arrow buttons 24f to 24i arranged in the center is selected. 24j, a display switching button 24k for switching the screen display on the display unit 22, a left guide selection button 24l for selecting the left guide displayed on the display unit 22, and a right for selecting the right guide displayed on the display unit 22. It includes a guide selection button 24m, a paper discharge tray open button 24n for opening the front door 14 having a function as a paper discharge tray, and the like.

  Further, in order to confirm the display content of the display unit 22, the cover 30 is provided with a window 32 having the same size as the display unit 22. That is, when the cover 30 is in the closed state, the user can check the display content of the display unit 22 through the window 32. On the other hand, when the cover 30 is in the open state, the display unit 22 can be adjusted to a desired angle as shown in FIG.

  Thus, when the cover 30 is in the open state, the cover 30 is held while being inclined obliquely rearward with respect to the operation panel 20 and can be used as a tray for supplying the paper P to the print mechanism 50. . Further, at the back of the operation panel 20, a paper feed port 58 of the print mechanism 50 is provided, and a pair of paper guides 59 that are slid in the left-right direction so that the guide width matches the paper width are provided. .

  Then, the paper P is sent to the print mechanism 50 through the paper supply port 58 and printing is executed. As shown in FIG. 2, the carriage 53 is driven by a timing belt 51 spanned in a loop shape in the left-right direction and reciprocates left and right along the guide 52. The carriage 53 is provided with a paper edge detection sensor 57 for detecting the left and right edges and the upper and lower edges of the paper P. In other words, the paper edge detection sensor 57 detects the left and right edges of the paper set in the paper supply port 58 before the printing, and allows the paper width to be recognized by detecting the right and left edges of the paper. Or detecting the trailing edge of the paper during printing to enable recognition of the paper length.

  The carriage 53 is mounted with an ink cartridge 54 that individually accommodates ink of each color such as cyan, magenta, yellow, and black. Each of these ink cartridges 54 is connected to a print head 55. The print head 55 applies pressure to the ink from the ink cartridge 54 and ejects the ink from the nozzle (not shown) toward the paper P. In this embodiment, the print head 55 employs a method in which a voltage is applied to the piezoelectric element to deform the piezoelectric element and pressurize the ink. However, a voltage is applied to the heating resistor (for example, a heater) to apply the ink. You may employ | adopt the system which pressurizes ink with the bubble generated by heating. The printed paper P is sent out to the opened front door (paper discharge tray) 14 by the transport roller 56.

  Although not shown, a battery pack can be attached to the back surface of the printer main body 12, and the printer 10 can be operated by a battery without being connected to a commercial power source. Because of this point and the fact that the printer 10 is a stand-alone printer that can be used without being connected to a host computer, the printer 10 is easy to carry and can be used anywhere.

  FIG. 3 is a block diagram showing the configuration of the controller. As shown in FIG. 3, the controller 70 is configured as a microprocessor centered on a CPU 711, and includes a ROM 72 that stores various processing programs and various data, various programs and various tables, and a RAM 73 that temporarily stores data. And an interface (I / F) 75 that enables communication with the printer mechanism 50, the memory card slot 16, and the like. Further, the controller 70 stores an edited image or the like in the memory card M, and outputs a control signal to the print head 55 of the print mechanism 50 and a control signal to the display 22 of the operation panel.

  In addition, the controller 70 is provided with an image processing module 712 for performing necessary image processing on image data provided from an external storage medium such as a memory card M through the interface 75. The image processing module 712 also has a function of generating image data corresponding to a printer-specific image such as a menu screen to be displayed on the display unit 22. A video RAM (VRAM) 713 for temporarily storing image data is connected to the image processing module 712.

  The RGB image data output from the image processing module is sent to an LCD controller 771 for controlling the display of the display unit 22 and a video encoder 772 for converting the RGB image data into a video signal compliant with the television broadcasting system. Given in parallel or selectively. In the following, the number of pixels of the display unit 22 constituted by the LCD display is 320 dots × 240 dots in the QVGA (Quarter Video Graphics Array) format, and the number of pixels of the video signal output to an external device such as a television receiver is It is assumed that the size is 640 dots × 480 dots in VGA (Video Graphics Array) format.

  The video encoder 772 has a function of outputting video signals of a plurality of television broadcasting systems having different signal formats, that is, a PAL system, an NTSC system, and a SECAM system, and among these, a format selection signal given from the CPU 711 is used. A video signal conforming to one designated signal format is output. The video signal is output to the output terminal 774 via the video amplifier 773, and the user displays an image on the television screen by connecting an external television receiver TV to the output terminal 774 via the video cable VC. Let me enjoy it. In addition, since a plurality of television broadcasting systems can be supported, the user can carry the photo printer 10 and connect it to a television receiver at a desired location.

  The output terminal 774 is provided with a television connection detection circuit 775. The television connection detection circuit 775 detects whether or not a television receiver serving as a load is connected depending on whether the output terminal 774 is open or terminated with a predetermined impedance (typically 75Ω). More preferably, the television receiver connected to the output terminal 774 may be configured to detect whether or not an image can be displayed.

  When the television receiver TV is connected to the output terminal 774, an image can be displayed on the television receiver TV by outputting a video signal from the printer 10 side. However, a plurality of incompatible video signal formats for the television broadcasting system are used all over the world, and the television receiver TV can accept the images in order to display the images correctly on the television receiver TV. It is necessary to output a video signal conforming to the signal format. Even if the format of the video signal output from the printer can be selected, it is not user-friendly to have the user select and set it in accordance with each television receiver. This is because a user who does not have expertise does not always know the signal format of the television receiver. Also, if the signal format is not compatible, abnormal video will be displayed or nothing will be displayed on the TV screen, but for general users it is due to signal format incompatibility or due to device abnormality It is not easy to judge whether it is a thing.

  Therefore, in the photo printer 10 according to this embodiment, a video signal output adapted to the signal format of the television receiver can be easily and surely performed even by a user having no specialized knowledge by executing the initial operation described below. It is possible to set.

  FIG. 4 is a flowchart showing an initial operation in this photo printer. In the photo printer 10, when the apparatus is turned on, the CPU 70 executes a program stored in advance in the ROM 72 of the controller 70, whereby the initial operation shown in FIG. 4 is executed. Further, even immediately after the power is turned on, for example, when the television connection detection circuit 775 detects that a new television receiver is connected, or when the execution of the initial operation is instructed by a user operation, the initial operation is performed. The action is executed. An instruction for executing an initial operation by a user operation can be selected from a menu screen displayed when the menu button 24b is pressed, for example.

  In the initial operation, it is first determined whether or not the television receiver is connected based on the detection result of the television connection detection circuit 775 (step S101). When a television receiver is connected to output terminal 774 (YES in step S101), it is subsequently determined whether format setting is necessary (step S102). When it is determined that the format setting is necessary, the format determination process (step S103) is subsequently executed to determine the signal format of the output signal. Whether or not format setting is necessary can be determined as follows, for example.

  That is, if the format has never been set in the device, it is determined that the format setting is necessary. In addition, format setting is required even if settings have been made in the past but the prohibition setting operation described later has not been performed by the user, and when the initial operation has been started by a user operation. It is judged that. On the other hand, if the setting has been performed in the past and the prohibition setting operation has been performed by the user at that time, it is determined that the format setting is unnecessary.

  FIG. 5 is a flowchart showing the format determination process. In this process, first, an image for operation explanation to be displayed on the display unit 22 is created on the character image layer which is a virtual layer on the VRAM 713 by the image processing module 712 (step S201). In this operation explanation image, characters preliminarily stored in the ROM 72 such as characters for explaining the operation and cursor symbols are arranged at predetermined positions on a 320 dot × 240 dot plane corresponding to the size (QVGA) of the display unit 22. This is an image.

  Then, the CPU 711 outputs a format selection signal to the video encoder 772 and temporarily sets the signal format of the video signal output from the video encoder 772 to a predetermined initial format (step S202), and the operation description from the image processing module 712. RGB image data corresponding to the work image is sent in parallel to the LCD controller 771 and the video encoder 772 (step S203).

  FIG. 6 is a diagram illustrating an example of an operation explanation image. As shown in FIG. 6, the operation explanation image 22a to be displayed on the display unit 22 is a matter to be confirmed by the user that the output mode setting operation is currently being executed (in this example, “correctly displayed on the TV screen”). Message is displayed? ") And a message to the user such as a description of the button to be operated. Here, the user is guided to press the OK button 24j when a correct image is displayed on the television screen, and to press other buttons when nothing is displayed. In this way, by assigning a button that accepts an operation in the format determination process to a button that is used to realize another function in the normal operation, a special operation input for a format determination process with a low effective frequency is performed. There is no need to provide means.

  The operation image 22 a is displayed on the display unit 22. On the other hand, on the TV receiver TV side, the same image is displayed if the signal format of the video signal sent from the printer side is compatible with that of the TV receiver, but what if the signal format is not compatible? Also not reflected.

  Returning to FIG. 5, the description of the format determination process will be continued. Since the user performs a predetermined button operation in accordance with the operation image displayed on the display unit 22, the user waits for any button operation (step S204), and determines what the pressed button is (step S205). . If the pressed button is other than the OK button, it means that the correct image is not currently displayed on the TV screen, that is, the signal format is not compatible with the TV receiver. Therefore, in this case, the signal format is switched to another one (step S206), and the video signal is transmitted again. As described above, when a button other than the OK button is pressed, the video signal is transmitted while sequentially switching the signal format according to the operation. In this way, a video signal suitable for the television receiver TV is output and a correct image is displayed. In addition, since the signal format is switched according to the user's button operation, even a user who is unfamiliar with the operation can perform the operation without panicking.

  In this embodiment, the operation explanation image displayed on the display unit 22 and the image displayed on the external television receiver TV are the same. However, the present invention is not limited to this, and the images may be different from each other. However, if both images have the same content, the projected image may be output from the printer only by looking at the television screen. It is convenient because it understands. In addition, an image displayed on the television screen has a small QVGA size, but this is not a problem for the purpose of setting the signal format of the video signal. In order to avoid this, it is possible to display an enlarged image without degrading the image quality by performing character rearrangement on the screen by an enlargement operation of a character image layer described later.

  If the button pressed at a certain point in time is an OK button, it means that the currently set signal format is compatible with the TV receiver TV. The signal format is set (step S207). Thereby, since the subsequent video signals are transmitted in the selected signal format, the user can immediately display an image on the television receiver unless the setting is changed.

  Further, in order to use the signal format selected here for the first time when the format determination process is performed next, the current signal format is set as the initial format in the next format determination process (step S208). The television broadcasting system is often fixed for each region, and the frequency of selecting the signal format is not so high, but the next format is decided by setting the previously selected signal format as a new initial format. The probability that the signal format used first in the processing is the desired one becomes high, and it becomes possible to reduce the time and time required for setting by reducing the operation time.

  Further, the user is allowed to select whether or not the subsequent format setting is prohibited (step S209). Unless the device is moved between areas with different broadcasting systems, basically, once the format setting is performed, it is not necessary thereafter. For example, if the format determination process described above is automatically executed each time the power is turned on, the user It is cumbersome for me. Therefore, if the user selects prohibition, the subsequent format determination process is prohibited (step S210), and the format determination process is not executed unless necessary, so that such a problem can be solved. . When it is desired to set the signal format again, it can be selected from the menu screen.

  As described above, in the photo printer 10 of this embodiment, a video signal is output while sequentially switching a plurality of signal formats, and the user presses a predetermined button when an image is displayed on an externally connected television screen. By doing so, the format of the video signal suitable for the television receiver TV is specified. Therefore, the user can easily and surely select an appropriate signal format and display a correct image on the television receiver without knowing the signal format adopted for the television receiver used by the user.

  Further, simply outputting a video signal for confirming the display does not allow the user to know what is the cause when the image is not displayed on the television screen and what to do to display correctly. On the other hand, in this embodiment, since the operation to be performed by the user is clearly indicated on the display unit 22 provided in the printer main body 12, the user can select the correct signal format without hesitation in the operation. Further, by making the content of the image output to the television receiver the same as the content of the image to be displayed on the display unit 22, the image displayed on the television screen is output from the printer 10 for the user. In addition, since the next operation to be performed is displayed on the television screen, the user can be made to perform the correct operation. In addition, since it is not necessary to individually prepare images to be displayed on the respective screens in the printer 10, the processing is simplified and memory resources are also saved.

  Returning to FIG. 4, the description of the initial operation will be continued. When the television receiver is not connected, when the format setting is unnecessary, and when the format determination process ends, an image corresponding to one of the image files such as a photographic image subsequently stored in the external medium Data (hereinafter referred to as “external image data”) is read out and developed into an external image layer which is a virtual layer on the VRAM 713. The image size at this time is assumed to be equivalent to QVGA (320 × 240 dots) corresponding to the display unit 22 (step S104). In addition, in order to display the operation icons, the remaining battery level, and the like in combination with the image, character image data corresponding to an image in which these icons are arranged in the QVGA size character image layer is separately generated (step S105). This image is formed by arranging characters whose image patterns are stored in advance in the ROM 72 while designating their coordinate positions.

  Subsequently, it is determined whether or not a television receiver is connected to the output terminal 774 (step S106). When the television receiver is not connected, the image is displayed on the display unit 22 provided at the top of the printer. That is, the image processing module 712 creates composite image data by superimposing the image data of the external image layer and the character image layer created in the QVGA size, and outputs them to the LCD controller 771 (step S107). . Thus, the character image generated in the printer is superimposed on the image read from the external medium and displayed on the display unit 22.

  On the other hand, when a television receiver is connected, the following is performed. In order to display an image on a television receiver, image data corresponding to the VGA size must be regenerated. This is because the image to be displayed becomes smaller if the QVGA size is maintained, and the significance of displaying on a large screen is diminished. First, the external image data is re-developed as a VGA size image on the external image layer of the VRAM 713 (step S108). In this case, it is not preferable to enlarge and use the image once developed to the QVGA size in step S104. This is because mere enlargement causes the image to become rough and the image quality to deteriorate significantly. Therefore, it is desirable to use the external image data stored in the external medium again and re-expand the image to obtain a VGA size image.

  On the other hand, character image data is basically a combination of characters and symbols and does not require a high resolution from the start because it is sufficient to ensure a certain level of legibility. In addition to this, the image is created by designating the coordinates on the image plane and arranging the characters. Therefore, by re-designating the coordinates, the image quality is reduced unlike when the image is simply enlarged by interpolation. It is possible to easily enlarge an image without deteriorating.

  Therefore, the character image layer is enlarged to the VGA size by recalculating the coordinate position according to the VGA size and rearranging each character, and is superposed on the previously developed external image layer of the VGA size. Thus, composite image data is obtained (step S109). By sending the composite image data thus obtained to the video encoder 772, a video signal corresponding to a VGA size image is given to the television receiver and the image is displayed.

  FIG. 7 is a conceptual diagram showing a state of image composition. When the display destination of the image is the display unit 22 which is an LCD display, as shown in FIG. 7A, the character image layer and the external image layer both developed in the QVGA size on the VRAM 713 are the image processing module 712. The composite image data obtained in this manner is output to the LCD controller 771 and the composite image is displayed on the display unit 22.

  On the other hand, when the image display destination is an external television receiver TV, as shown in FIG. 7B, the image processing module 712 displays each character on the character image layer created in the QVGA size. By recalculating the coordinate position, it is rearranged on the image plane of VGA size, and this is superimposed on the external image layer developed to VGA size, thereby obtaining VGA size composite image data. The composite image data obtained in this manner is sent to the video encoder 772, and the video encoder 772 outputs the selected signal format video signal, whereby the composite image is displayed on the television receiver TV.

  As described above, in this embodiment, since the image read from the external medium is displayed based on the image data developed in accordance with the image size of the display destination, it is good in any display destination. Image quality is obtained. Further, since the character image generated in the printer is enlarged by rearrangement of each character, good image quality can be obtained. This also makes it possible to reduce the required VRAM capacity.

  FIG. 8 is a diagram showing a memory map of the VRAM. The VRAM 713 stores image data corresponding to each of the character image layer and the external image layer. As described above, the character image layer is created in the QVGA size regardless of the display destination of the image. It is sufficient that a data area of 320 × 240 dots is secured. As for the external image layer, when the image display destination is an external television receiver TV, the image is developed in the VGA size, so that a data area of 640 × 480 dots is required. Therefore, as the data capacity of the VRAM 713, it is sufficient that the capacity obtained by adding the QVGA size for one screen to the VGA size for one screen is a minimum. This is greatly reduced compared to the capacity for securing the VGA size data capacity for both image layers and the capacity for individually preparing the screens corresponding to each of the display unit 22 and the television receiver TV. Yes. In particular, the effect is great when there are a plurality of character image layers.

  FIG. 9 is a diagram showing image composition in the case of having a plurality of character image layers. More specifically, FIG. 9A is a conceptual diagram showing a state of image composition when a plurality of character image layers and an external image layer are overlapped to create VGA size composite image data. FIG. 9B is a diagram showing a VRAM map for enabling this. When a plurality of character image layers are provided, frames, characters, decorative parts, and the like to be displayed together with an image given from an external medium can be arranged on individual layers to increase the degree of freedom of image editing. In this case, as shown in FIG. 9A, each character image layer is created in a QVGA size. Then, each character image layer is synthesized while being enlarged to the VGA size by rearranging the characters, and is temporarily stored in a data area corresponding to the synthesized character image layer provided on the VRAM 713, and thus obtained VGA size synthesized character image is obtained. Composite image data is created by superimposing a layer and an external image layer of a VGA size separately developed.

  In this case, as shown in FIG. 9B, a data area of 640 × 480 dots is required on the VRAM 713 in order to save the composite character image layer. Compared with the case where images are individually developed on the VRAM 713, the memory size can be greatly reduced.

  As described above, in this embodiment, a character image layer having no image deterioration caused by enlargement / reduction is created with a small QVGA size regardless of the display destination, while an external image layer in which image quality is important. Develops images according to the size of the display destination, and superimposes them to create composite image data. Therefore, good image quality can be obtained at any display destination. Further, it is not necessary to provide an image processing module for each display destination, and image data processing for displaying an image on a different display destination can be performed efficiently.

  As described above, in the above embodiment, the CPU 711, the display unit 22, the video encoder 772, and the button group 24 are the “control unit”, “display unit”, “video signal output unit”, and “accepting unit” of the present invention, respectively. Is functioning. The television connection detection circuit 775 functions as the “detection means” of the present invention. In the above embodiment, the operation explanation image 22a output to the display unit 22 and the television receiver TV in the format determination process corresponds to the “description image” and the “test image” of the present invention. . That is, the above embodiment corresponds to the case where the “description image” and the “test image” of the present invention have the same contents. In the present embodiment, the television receiver TV corresponds to an “external display device” according to the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the format determination process of the above embodiment, the signal format is switched when the user presses a button other than the OK button. However, as shown below, the signal format is automatically switched. Also good.

  FIG. 10 is a flowchart showing a modification of the format determination process. In this format determination process (2), an image for explanation of operation is created in the QVGA size, and the image data is temporarily set to the initial format for the LCD controller 771 and the video signal format and sent to the video encoder 772. This is the same as the above embodiment (corresponding to steps S301 to S303 and steps S201 to S203 in FIG. 5).

  However, in this modification, the time for transmitting a video signal in one signal format is limited. That is, the operation when the OK button is pressed while sending a video signal in a certain signal format is the same as in the above embodiment (corresponding to steps S307 to S310, steps S207 to S210 in FIG. 5), but the button operation is If not, the signal format is cyclically switched when a predetermined time has elapsed (steps S304 to S306). As this predetermined time, it is necessary to give a sufficient time for the user to check the screen and perform the button operation, and can be, for example, about 5 seconds.

  In this way, even when the user does not perform any operation, a correct image is displayed on the television screen for a certain period by periodically changing the signal format. Therefore, for example, even when the user does not notice the screen display on the main body side and is not aware of the necessary operation, the user is made aware that the operation is necessary by the explanatory image displayed on the television screen in a short time. It becomes possible.

  Further, in the above embodiment, the signal format switching order in the format determination process that is executed first is fixed in advance, but it may be as follows. This type of printer 10 may be provided with a function for a user to select and set a use region or a display language in the initial setting of the apparatus. This is a function for making it possible to provide different menus depending on the region of use, and for allowing the display language on the menu screen or the like to match the user's wishes. When such a function is provided, the order of each signal format may be determined in conjunction with the setting.

  As described above, since the television broadcasting system is determined by the region, if the use region or the display language is determined, the signal format that may be used can be specified to some extent. In this way, it is possible to prioritize and output signal formats that are likely to be used in the region over other formats, so that it is possible to reduce the operation and complete the processing in a short time. It becomes possible. The use area may be set in advance at the time of shipment according to the destination of the product. Further, the order may be determined depending on the combination of the use area and the language.

  FIG. 11 is a diagram illustrating an example of a language used for each region and a television broadcasting system. As can be seen from the figure, for example, when the usage region is the Americas, the NTSC system is widely used, so the NTSC system may be used as the initial format regardless of the language setting. For example, when the language setting is English but the region is unknown, it is not possible to specify which of the NTSC and PAL methods is preferred, but at least these methods should be used preferentially over the SECAM method. . For example, when the language setting is French, the SECAM method should be given the highest priority if the use region is Europe, but the NTSC method is preferably given priority if the use region is the Americas.

  In addition, when the language and the broadcasting system have a one-to-one correspondence, such as when the display is in Japanese, the broadcasting system may be fixed, but it is taken out to other areas. Considering that the broadcasting system may be used, it is better in terms of convenience for the user that the broadcasting system is used as the initial format and that it is possible to change to another signal format.

  In the above embodiment, the signal format is switched between a plurality of incompatible television broadcasting systems. However, the present invention is not limited to this, for example, between an analog system and a digital system. It is possible to apply to the case of selecting the one that is suitable for the display device from different signal formats such as between the television broadcasting system and the high-definition broadcasting system, and between the QVGA system and the VGA system. This is particularly effective when selecting from formats that share the same output terminal and cable standards.

  In addition to the photo printer as in the above-described embodiment, the present invention has its own display means such as a digital camera or a PDA (Personal Digital Assistant) device and can also output a video signal to an external display device. The present invention can be applied to electronic devices configured as described above. Furthermore, since the image to be displayed is not limited to a still image, it can also be applied to a device that outputs moving images, such as a movie camera.

1 is a perspective view showing a photo printer which is an embodiment of an image display device of the present invention. FIG. 2 is a diagram illustrating an outline of an internal configuration of a photo printer. The block diagram which shows the structure of a controller. 3 is a flowchart showing an initial operation in this photo printer. The flowchart which shows a format determination process. The figure which shows an example of the image for operation description. The conceptual diagram which shows the mode of image composition. The figure which shows the memory map of VRAM. The figure which shows the image composition in the case of having a some character image layer. The flowchart which shows the modification of a format determination process. The figure which shows an example of the use language for every area, and a television broadcast system.

Explanation of symbols

  22 ... Display unit (display means), 22a ... Operation explanation image (description image, test image), 24 ... Button group (reception means), 711 ... CPU (control means), 772 ... Video encoder (video signal output means) 775, TV connection detection circuit (detection means), TV ... TV receiver (external display device)

Claims (9)

Video signal output means having a function of generating video signals conforming to a plurality of different signal formats, and outputting the video signal conforming to one of the selected signal formats to an external display device;
Control means for designating the selection signal format to the video signal output means;
Display means for displaying an image;
Receiving means for receiving an operation input from a user, the control means,
When the video signal corresponding to a predetermined test image is output from the video signal output means while sequentially switching the plurality of signal formats, and when the test image is displayed on an external display device to the user An explanation image for requesting the reception unit to perform a predetermined operation input is displayed on the display unit, and is output from the video signal output unit when the user inputs the predetermined operation input to the reception unit. An image display apparatus that executes a format determination process for determining a signal format of the video signal as the selection signal format.   The image display apparatus according to claim 1, wherein the control unit automatically switches a signal format of a video signal output from the video signal output unit in a predetermined cycle in the format determination process.   The image display apparatus according to claim 1, wherein the control unit switches a signal format of a video signal output from the video signal output unit in accordance with a user switching operation in the format determination process.   The image display device according to claim 1, wherein the test image and the explanation image have the same content.   5. The image display device according to claim 1, wherein the control unit changes a signal format switching order in the format determination process according to a result of the format determination process executed in the past. Detecting means for detecting whether an external display device is connected to the video signal output means;
6. The image display device according to claim 1, wherein the control unit executes the format determination process when the detection unit detects that an external display device is newly connected.   After the selection signal format is determined by the format determination process, the control unit prohibits subsequent execution of the format determination process regardless of the detection result of the detection unit when a user performs a predetermined prohibition setting operation. The image display device according to claim 6. The display means is capable of displaying the explanatory image in one language selected by a user among the plurality of explanatory images described in characters of different languages.
The image display device according to claim 1, wherein the control unit changes a signal format switching order in the format determination process according to a language selection by a user. From the video signal output means having a function of generating video signals conforming to a plurality of different signal formats, the video signal corresponding to a predetermined test image is displayed on the external display device while sequentially switching the plurality of signal formats. Output against
When the test image is displayed on the external display device, an explanation image for requesting the user to perform a predetermined operation input to the accepting means is displayed on the display means for displaying an image,
Determining the signal format of the video signal output from the video signal output means when the predetermined operation input from the user to the receiving means as a selection signal format;
Thereafter, a signal format of a video signal output from the video signal output means is set to the determined selection signal format.

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