JP2006011067A - Television and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of making sticking on the display screen inconspicuous without increasing the manufacturing cost. <P>SOLUTION: In response to prescribed operation from a remote controller 40, image data of a still picture causing the sticking are held in a frame memory 23f as a work area that a color decoder 23a can be used. In response to an indication to display a reversal image made with the remote controller 40, the luminance of the image data held in the frame memory 23f is inverted and the reversal image is displayed on a PDP panel 31 to make the whole display screen of the PDP 31 uniform. Consequently, there is no need for providing an extra memory for storing the image data of the image causing the sticking, so an increase in manufacturing cost can be suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device using a plasma display panel (PDP picture) or the like that displays an image by causing a light emitter to emit light.

  In a display device provided with a plasma display panel (PDP), each color signal R (red), G (green), and B (blue) is made to emit light to display a color image. In such a display device, there is a problem that burn-in occurs on the display screen in accordance with display contents and usage time because the light emitter emits light. For example, if the same OSD display is continuously performed for a long time, or a still image in the middle of a television game is continuously displayed for a long time, the burn-in based on the brightness difference of the still image is generated. Occurs and the display screen becomes difficult to see.

In order to solve such a problem, there has been disclosed a display device that can make the display screen image inconspicuous by displaying an inverted image obtained by inverting the luminance of the input video signal (for example, Patent Documents 1 and 2).
JP 11-298226 A JP 11-298226 A

  However, in the display devices described in Patent Documents 1 and 2, a configuration is provided in which a dedicated memory for storing a still image on which an inverted image is displayed, that is, a still image in which burn-in has occurred, is separately provided. This causes a problem that the cost for manufacturing the display device is increased.

  In view of such circumstances, the present invention provides a display device capable of making display screen image sticking less noticeable without increasing manufacturing costs.

In order to achieve the above object, the invention according to claim 2 includes a first display image display means for displaying a predetermined display image based on an input video signal,
A display device comprising: second display image display means for displaying an inverted image obtained by inverting the luminance of the input video signal;
In response to a predetermined stop operation, the image data of the display image displayed by the first display image display means is stored in a frame memory capable of storing one frame of image data. Image data storage means;
The image data storage means comprises display control means for displaying the inverted image on the second display image display means based on the image data stored in the frame memory. .

  In the second aspect configured as described above, the first display image display means displays a predetermined display image on the display unit based on the input video signal. The second display image display means displays an inverted image obtained by inverting the luminance of the input video signal.

  Further, the image data storage means stores the image data of the display image displayed by the first display image display means in accordance with a predetermined stop operation. The data is stored in a frame memory that can store the data. Further, the display control means causes the second display image display means to display the inverted image based on the image data stored in the frame memory by the image data storage means. The frame memory includes a video decoder for executing predetermined processing on an input video signal, a scaler for converting a digital video signal in accordance with the screen size of the display unit, and the like as a work area. It is possible to store image data of a still image when burn-in occurs using this frame memory. As a result, it is not necessary to provide an additional memory for storing image data of a still image when burn-in occurs, so that an increase in manufacturing cost can be suppressed.

Further, according to a third aspect of the present invention, the display control means includes a portion where the brightness of a still image based on the image data is high and low with respect to the image data stored in the image data storage means. The reverse image is displayed so as to make a boundary with the part.
In claim 3 configured as described above, when the image is reversed as a result of displaying the inverted image, the boundary between the high and low portions of the original still image is made inconspicuous. It becomes possible.

Furthermore, the invention according to claim 4 includes an all-white image display means for displaying an all-white image for visually confirming the burn-in of the display screen.
According to the fourth aspect configured as described above, it is possible to perform a visual confirmation of a display screen that has been made uniform by displaying a burn-in state of the display screen when a burn-in occurs or a reverse image.

Furthermore, the invention according to claim 5 detects the movement of the input video signal, and specifies a case where there is no movement over a predetermined time as a still image,
Comprising time measuring means for measuring the elapsed time since the still image is specified by the specifying means,
The display control means is configured to display the inverted image over the elapsed time measured by the time measuring means.
In claim 5 configured as described above, it is possible to display an inverted image over the same time as the time when a still image related to the occurrence of burn-in was displayed, so that the display screen can be made more uniform. This makes it possible to make the display screen image more inconspicuous.

Furthermore, the invention according to claim 6 comprises a still image display means for displaying a still image based on the image data stored in the frame memory by the image data storage means.
In the sixth aspect configured as described above, it is possible to confirm the original still image in which the burn-in has occurred.

Furthermore, the invention according to claim 7 includes a video input terminal capable of inputting an input video signal from an external device, and displays a game image based on the input video signal from the game device as the external device. The game mode to be displayed can be selected, and the display control means displays the inverted image on the second display image display means when the game mode is selected. is there.
In the seventh aspect configured as described above, even if burn-in occurs due to an input video signal from a television game or the like, burn-in of the display screen is made inconspicuous by displaying an inverted image. Is possible.

Furthermore, the invention according to claim 8 is configured such that the display unit includes a plasma display panel.
According to the eighth aspect configured as described above, it is possible to make the display screen of the plasma display panel inconspicuous.

In the invention according to claim 2 of the present invention, it is possible to make the display screen image sticking out while suppressing an increase in manufacturing cost.
In the invention according to claim 3, it becomes possible to make the boundary between the high-luminance portion and the low-luminance portion of the original still image where burn-in occurs inconspicuous.
In the invention according to claim 4, it is possible to perform visual confirmation of the display screen.
In the invention according to claim 5, it is possible to make the burn-in of the display screen less noticeable.
In the invention according to claim 6, it is possible to confirm the original still image in which the burn-in has occurred.
In the invention according to claim 7, even when burn-in occurs due to an input video signal from a television game or the like, it is possible to make the burn-in of the display screen inconspicuous by displaying an inverted image. Become.
In the invention according to the eighth aspect, it is possible to make the burn-in of the display screen of the plasma display panel inconspicuous.

  FIG. 1 is a block diagram showing a configuration of a display device (PDP display device) as a television provided with a plasma display panel according to the present invention. In the figure, the PDP display device 20 includes a tuner unit 22 for inputting a frequency signal from the antenna 10. The tuner unit 22 is configured as a so-called synthesizer type tuner, and PLL data as a channel selection control signal, that is, data of a frequency division ratio of a variable frequency dividing circuit in the PLL loop is selected. Given to part 22.

  The PDP display device 20 includes a video input terminal 24. A game device 50 as an external device is connected to the video input terminal 24, and a video signal and an audio signal from the game device 50 can be input via the video input terminal 24. A switch circuit 25 is connected to the tuner section 22 and the video input terminal 24 described above. The switch circuit 25 is for enabling either the video signal from the tuner unit 22 or the video signal from the video input terminal 24 to be supplied to the video signal processing unit 23 described later. That is, the display device 20 according to the present invention is configured to be able to perform both television broadcast reception and game video display from the game device.

  The output from the tuner unit 22 or the video input terminal 24 is supplied to the video signal processing unit 23. The video signal processing unit 23 includes a color decoder 23a, an IP conversion unit 23b, a scaler 23c, and a display image adjustment unit 23e. The color decoder 23a demodulates R, G, and B primary color signals from the input signal. The color decoder 23a includes an A / D converter (not shown), and converts the input R, G, B primary color signals into digital signals. Further, the color decoder 23a also separates the video signal and the audio signal and supplies the separated audio signal to a D / A converter 32 described later. The color decoder 23a further includes an OSD processing unit 23d. The OSD processing unit 23d can perform processing such as displaying a predetermined still image superimposed on a video or displaying a predetermined still image by replacing it. The OSD processing unit can input data such as character information from the CPU 28a, and can generate a still image based on the data such as the character information.

  The IP converter 23b converts a continuous interlaced video signal into a progressive video signal. The scaler 23 c converts the input digital video signal so as to match the screen size of the PDP panel 31. The color decoder 23a, the IP conversion unit 23b, and the scaler 23c can use the frame memories 23f, 23g, and 23h as work areas when performing the respective processes. Yes.

  A motion detector 26 is connected to a frame memory 23f as a work area that can be used by the color decoder 23a. The motion detector 26 detects a difference between frames (image data for one screen) of the video signal stored in the frame memory 23f, and there is no motion for a predetermined time or more based on this difference. The case is determined to be a still image, and the other cases are determined to be moving images. And the detection result of the motion detection part 26 is transmitted to CPU28a. When the CPU 28a receives a determination result indicating that the image is a still image from the motion detection unit 26, the CPU 28a measures an elapsed time (T) from that point. The PDP display device 20 according to the present invention displays a reverse image over the same time as this elapsed time (T).

  Further, based on a predetermined stop operation from the remote controller 40 or the like, the CPU 28a holds the image data stored in the frame memory 23f and displays a still image based on the image data on the PDP panel 31. To control. In this way, for example, a user who has noticed that a game image has been displayed over a long period of time can check a still image that may cause burn-in of the display screen. Become.

  The display image adjustment unit 23e includes a γ correction circuit, and generates a display image based on the input video signal and generates a reverse image based on a command from the CPU 28a. The display image adjusting unit 23e responds to a command from the CPU 28a based on a predetermined operation by the remote controller 40 or the like when image data is held in the frame memory 23f in response to a stop operation by the remote controller 40 or the like. Thus, a process of generating an inverted image in which the luminance of the image data is inverted is performed. The display image adjusting unit 23e will be described in detail later with reference to the drawing (FIG. 2).

  The PDP drive unit 30 includes an LVDS conversion circuit and the like, and performs a process of displaying various images on the PDP panel 31 in accordance with an output from the display image adjustment unit 23e. The audio signal output from the color decoder 23 a is input to the amplifier / speaker 33 via the D / A converter 32.

  The CPU 28a described above is connected to the bus 29, and executes control processing for realizing various functions of the PDP display device 2 while using the RAM 28b connected to the bus 29 as a work area. Further, a rewritable EEPROM 28d is connected to the bus 29, and control processing is executed using various data stored in the CPU 28a and the EEPROM 28d.

  Channel selection data 28d1 is stored in the EEPROM 28d. The channel selection data 28d1 is for selecting a frequency band received by the tuner unit 22 based on a channel selection instruction for a reception channel from the remote controller 40 or the like. The EEPROM 28d stores OSD data 28d2 for causing the OSD processing unit 23d described above to perform OSD processing.

  A remote control I / F 28e is connected to the bus 29, and an infrared blinking signal output from the remote control 40 can be input. This infrared blinking signal is sent to the CPU 28a via the bus 29, and the CPU 28a executes a corresponding control process.

  FIG. 2 is a block diagram showing a configuration of the display image adjustment unit shown in FIG. As shown in the figure, the display image adjustment unit 23e includes three display image generation circuits 60, 62, and 64, and three inverted image generation circuits 61, 63, and 65. The display image generation circuit 60 and the inverted image generation circuit 61 receive the R digital signal (R signal) demodulated by the color decoder 23a. The display image generation circuit 62 and the reverse image generation circuit 63, the display image generation circuit 64, and the reverse image generation circuit 65 receive the G signal and the B signal, respectively. The display image generation circuit 60 and the reverse image generation circuit 61 are connected to a switch circuit 66, and these two circuits can be switched. Similarly, the display image generation circuit 62, the reverse image generation circuit 63, the display image generation circuit 64, and the reverse image generation circuit 65 are connected to switch circuits 67 and 68, respectively.

  The display image generation circuit 60 includes a ROM 60a, and the ROM 60a stores a display image generation lookup table for generating a display image by performing γ correction. An example of this lookup table is shown in FIG. In the figure, the output gradation value after γ correction is associated with each input gradation value. That is, by using this lookup table, it is possible to uniquely obtain the output gradation value after γ correction from the input gradation value. When the display image generation circuit 60 is enabled by the switch circuit 66, γ correction based on the lookup table is performed on the R signal input to the display image generation circuit 60, and the correction is performed. The later R signal is output.

  On the other hand, the reverse image generation circuit 61 includes a ROM 61a, and the ROM 61a also stores a reverse image generation look-up table for performing γ correction. An example of this lookup table is shown in FIG. In the same figure, as in the display image generation lookup table shown in FIG. 3, output gradation values after γ correction are associated with each input gradation value. The brightness is inverted as compared with the look-up table. When there is an instruction to display a reverse image by operating the remote controller 40 or the like, the R signal obtained from the image data held in the frame memory 23f is used for the γ based on this lookup table. Correction is performed, and the corrected R signal is output.

  The display image generation circuit 62 and the reverse image generation circuit 63 to which the G signal is input, and the display image generation circuit 64 and the reverse image generation circuit 65 to which the B signal is input also include ROMs 62a, 63a, 64a, and 65a, respectively. Yes. The ROM 62a and 64a store a display image generation look-up table similar to that shown in FIG. 3, and the ROMs 63a and 65a have a reverse image generation look similar to that shown in FIG. The uptable is stored. When the γ correction is performed on the R, G, and B signals by the display image generation circuits 60, 62, and 64, a normal display image based on the video signal is obtained. When γ correction is performed on the G and B signals by the inverted image generation circuits 61, 63, and 65, respectively, an inverted image based on the image data held in the frame memory 23f is obtained. It is done.

  Next, the flow of the main process executed in the PDP display device 20 shown in FIG. 1 will be described based on the flowchart shown in FIG. First, in step S100, initial setting is performed. In this processing, initial settings such as clearing of the register in the CPU 28a, the RAM 28b, and reading of setting data for white balance adjustment from the EEPROM 28d are performed.

  Next, in step S110, it is specified whether or not the input is a television. In this processing, the switch circuit 25 shown in FIG. 1 specifies whether the video signal from the tuner section 22 is valid. That is, it is specified whether or not a television broadcast is being received.

  If it is determined in step S110 that the input is a television, a television broadcast image receiving process is performed in step S120. In this process, the CPU 28a controls each part and each circuit constituting the PDP display device 20 based on the currently set channel number, and displays a TV image corresponding to the channel number on the PDP panel 31. Execute the process. On the other hand, if it is determined in step S110 that the input is not TV input (video input), a process of displaying a display image based on the input video signal from the game apparatus 50 is executed in step S130. . As a result, the game image is displayed on the PDP panel 31.

  After the process of step S120 or step S130 is executed, it is next determined in step S140 whether or not there has been a stop operation. In this process, for example, a user who has noticed that a game image or an OSD image has been displayed for a long period of time, for example, to display an inverted image and perform maintenance of the display screen. Then, it is specified whether or not there is an operation for stopping the currently displayed image. If there is a stop operation, a reverse image display process is executed in step S150. This reverse image display processing will be described in detail later with reference to the drawing (FIG. 6).

  On the other hand, if it is determined in step S140 that no stop operation has been performed, it is specified in step S160 whether or not there is an instruction to turn off the power of the PDP display device 20. If there is no instruction to turn off the power of the PDP display device 20, the process returns to step S110, and if an instruction is input, the main process is terminated.

  Next, the flow of the reverse image display process that is called and executed in step S150 of the flowchart shown in FIG. 5 will be described with reference to FIG. First, in step S200, a process for holding the image data in the frame memory is executed. In this process, a process of holding the image data of the image displayed when the user performs a stop operation in the frame memory 23f is executed.

  Next, in step S210, a process of displaying a still image based on the image data held in the frame memory 23f by the process of step S200 on the PDP panel 31 is executed. By performing this process, it is possible to confirm the image that caused the burn-in of the display screen.

  Next, in step S220, a process for displaying the elapsed time (T) is performed. In this process, the elapsed time (T) from when the motion detection unit 26 determines that the image is a still image, that is, the time during which the image causing the burn-in of the display screen is displayed is displayed on the PDP panel 31. Process.

  Next, in step S230, it is specified whether or not there is an instruction to display an all-white image. In this process, it is determined whether or not an instruction to display an all white image on the PDP panel 31 for confirming the degree of burn-in of the display screen is made by operating the remote controller 40 or the like. If there is an instruction to display an all-white image, the all-white image is displayed on the PDP panel 31 in step S240.

  When the process of step S240 is executed, or when it is specified in step S230 that there is no instruction to display an all-white image, it is specified in step S250 whether an instruction to display an inverted image has been issued. In this process, it is specified whether or not an instruction to display a reverse image has been input by operating the remote controller 40 or the like. If there is no instruction to display the reverse image, the reverse image display process is terminated.

  On the other hand, if it is determined in step S250 that a reverse image display instruction has been issued, a process of displaying the reverse image is performed in step S260. Specifically, the switch circuits 66, 67, and 68 are switched by a command signal from the CPU 28a to enable the inverted image generation circuits 61, 63, and 65, and the image data stored in the frame memory 23f is displayed. The R, G, and B signals demodulated from the data are subjected to γ correction based on the inverted image generation lookup table, and the inverted image based on the corrected R, G, and B signals is displayed on the PDP panel. 31 is displayed. At this time, it is desirable to display an inverted image so that the boundary portion where the difference between the high luminance portion and the low luminance portion is equal to or higher than a predetermined level is obscured. Specifically, for example, for the boundary portion where the difference between the high luminance portion and the low luminance portion is equal to or higher than a predetermined level, the gradation value of a plurality of pixels adjacent to a certain pixel A and the gradation value of the pixel A Is corrected so as to be the gradation value of the pixel when displaying the inverted image, so that the boundary portion is uniformly blurred.

  If the process of step S260 is performed, the process which starts the measurement of display time (t) will be performed in step S270 next. This display time (t) is the time during which the reverse image is displayed on the PDP panel 31. Next, in step S280, whether or not t <T is specified for the display time (t) of the reverse image and the elapsed time (T) described above. If t <T, the process returns to step S280. If t <T is not satisfied (t = T), the display of the reverse image is terminated in step S290, and then the reverse image display process is performed. End. Although not shown in FIG. 6, it may be configured so that the uniformity of the display screen can be checked by displaying the all-white image after the display of the inverted image is completed.

  Hereinafter, a specific example when the reverse image display process shown in FIG. 6 is executed will be described. In response to the user's predetermined stop operation from the remote control 40 or the like, first, the image data of the image displayed on the PDP panel 31 when the stop operation is performed is stored in the frame memory. 23f (step S200). Then, a still image based on the stored image data is displayed on the PDP panel 31 (step S210), and the user can confirm the still image that caused the burn-in of the display screen. At the same time, it is displayed on the elapsed time (T) screen where the still image was displayed (step S220). Further, an all white image for confirming the degree of image sticking on the display screen is displayed in accordance with an instruction from the user (step S240). Thereafter, when the user gives an instruction to display the reverse image, the reverse image is displayed for the same time as the elapsed time (T) (steps S260 to S290).

  In the above-described embodiment, when the user performs a stop operation, the image data of the still image is held in the frame memory 23f that is the work area of the color decoder 23a. However, in the present invention, image data may be held in a frame memory used as a work area when performing predetermined processing on an input video signal. The display device may be configured such that the IP conversion unit 23b and the scaler 23c hold the image data.

  In the flow chart shown in FIG. 5, whether it is a TV input or a video input, it is shown in FIG. 6 according to the stop operation by the user. In the present invention, as shown in FIG. 7, a game mode for displaying a game image from a game device as an external device is described. Further, the PDP display device is configured such that the reverse image display processing is executed only in response to the above-described stop operation only when the game mode is selected. Also good.

  In the main process shown in FIG. 7, after the initial setting process of step S100 is executed, it is determined whether or not the game mode is selected in step S300, and the game mode is selected. Steps S130, S140, and S150 are performed, but when the game mode is not selected (TV input), the television broadcast reception process of Step S120 is performed. Then, since the process is moved to step S160, the reverse image display process of step S150 is not executed.

  As described above, in the PDP display device 10 according to the embodiment, based on a predetermined stop operation from the remote controller 40, the cause of burn-in in the frame memory 23f, which is a work area that can be used by the color decoder 23a. Since the image data of the still image is retained, it is not necessary to provide an additional memory for storing the image data of the still image when burn-in occurs. An increase in cost can be suppressed.

It is a block diagram which shows the structure of a PDP display apparatus. It is a block diagram which shows the structure of a display image adjustment part. It is a figure which shows an example of the look-up table for display image generation. It is a figure which shows an example of the look-up table for reverse image generation. It is a flowchart showing the flow of main processing. 6 is a flowchart showing the flow of the reverse image display process called in step S150 of the flowchart of FIG. It is a flowchart showing another example of the main processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Antenna 20 ... PDP display device 22 ... Tuner part 23 ... Video signal processing part 23a ... Color decoder 23b ... IP conversion part 23c ... Scaler
23d ... OSD processing unit 23e ... display image adjustment unit 23f ... frame memory 26 ... motion detection unit 28a ... CPU
28b ... RAM
28d ... EEPROM
DESCRIPTION OF SYMBOLS 30 ... PDP drive part 31 ... PDP panel 40 ... Remote control 60, 62, 64 ... Display image generation circuit 61, 63, 65 ... Reverse image generation circuit

Claims (8)

First display image display means for displaying a predetermined display image on the plasma display panel based on the input video signal;
In a television comprising second display image display means for displaying an inverted image obtained by inverting the luminance of the input video signal,
Identifying means for detecting the movement of the input video signal and identifying a case where there is no movement for a predetermined time as a still image;
A time measuring means for measuring an elapsed time after being identified as a still image by the identifying means;
In response to a predetermined stop operation, the image data of the display image displayed by the first display image display means is stored in a frame memory capable of storing one frame of image data. Image data storage means;
Still image display means for displaying a still image based on the image data stored in the frame memory by the image data storage means;
Based on the image data stored in the frame memory by the image data storage means, the luminance of the still image based on the image data is maintained over the elapsed time measured by the game timing means. With respect to the boundary between the high part and the low part, display control means for displaying the reverse image so as to make the boundary look like it,
A television comprising: an all-white image display means for displaying an all-white image for visually confirming burn-in of a display screen. First display image display means for displaying a predetermined display image on the display unit based on the input video signal;
A display device comprising: second display image display means for displaying an inverted image obtained by inverting the luminance of the input video signal;
In response to a predetermined stop operation, the image data of the display image displayed by the first display image display means is stored in a frame memory capable of storing one frame of image data. Image data storage means;
Display control means for causing the second display image display means to display the inverted image based on the image data stored in the frame memory by the image data storage means. Display device.   The display control means, for the image data stored in the image data storage means, takes a boundary between a high luminance portion and a low luminance portion of a still image based on the image data, The display device according to claim 2, wherein the reverse image is displayed.   4. The display device according to claim 2, further comprising an all-white image display unit that displays an all-white image for visually confirming burn-in of the display screen. Identifying means for detecting the movement of the input video signal and identifying a case where there is no movement for a predetermined time as a still image;
Comprising time measuring means for measuring the elapsed time since the still image is specified by the specifying means,
The display device according to claim 2, wherein the display control unit displays the inverted image over an elapsed time measured by the time measuring unit.   6. A still image display means for displaying a still image based on the image data stored in the frame memory by the image data storage means. The display device described. Provided with a video input terminal capable of inputting an input video signal from an external device,
A game mode for displaying a game image can be selected based on an input video signal from a game device as the external device,
7. The display control unit according to claim 2, wherein the display control unit causes the second display image display unit to display the reverse image when the game mode is selected. The display device described. The display device according to claim 2, wherein the display unit includes a plasma display panel.

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