JP2005202050A - Display device and display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device by which image persistence is prevented without degrading the quality of a display image, and also to provide a display method. <P>SOLUTION: The display device 10 is provided with an AC type color PDP 101, data driver circuits 102a to 102e and scan driver circuits 103a to 103c in a display element, and also is provided with: a video signal processing circuit for performing conversion and processing of the video signal inputted to the the driver circuit section; a driving signal generating circuit for outputting the driving signal to the respective circuits according to a synchronizing signal; and a high voltage driving circuit for supplying a high voltage powder source to the respective data driver circuits according to the driving signal inputted from the driving signal generating circuit. The input side of the video signal processing circuit of the driving circuit section is provided with an image persistence prevention processing circuit which subjects the video signal of the specific region to the image persistence prevention processing for the specific period. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a matrix display device such as a plasma display and a display method thereof, and more particularly to a display device and a display method capable of preventing image sticking.

  In a surface discharge type plasma display panel (PDP), a pair of glass substrates are arranged to face each other, one of which is provided with row electrodes extending in the row direction of the display surface, and the other is provided with the other. A column electrode serving as a data electrode is provided extending in the column direction of the display surface. A dielectric layer is provided on the row electrode, and a phosphor layer is provided on the column electrode. Further, a partition is provided between each column electrode on the phosphor layer, and a gap between the pair of glass substrates is held by the partition. As a result, a plurality of cells are formed which are partitioned by the partition between the pair of glass substrates and arranged in a matrix.

  In the PDP configured as described above, gas is sealed between a pair of substrates, and the row electrode and the column electrode are separately driven, whereby the intersection of the driven row electrode and the column electrode. Plasma discharge is generated in the gas in the cell located in the portion, and the phosphor provided on the column electrode is excited by this plasma discharge to emit light. Further, in the case of a PDP that performs color display, a phosphor layer that emits light of any one of R (red), G (green), and B (blue) is formed on each column electrode, and each column electrode is provided. Drive separately. As a driving method in this case, as a row electrode, for example, an X electrode provided in common for each row and a Y electrode provided for each row are alternately arranged, and between the X electrode and the Y electrode. A method in which voltage pulses are alternately applied to cause discharge whose polarity is inverted every half cycle, that is, an AC (alternating current) driving method is generally applied.

  In such an AC drive type PDP (hereinafter referred to as AC type PDP), once a discharge occurs in the cell, electrons and ions generated in the discharge space accumulate on the dielectric layer to form wall charges. However, after the wall charges are formed, the discharge is performed even at a low voltage due to the action of the electric field. Therefore, the discharge can be maintained by inverting the low voltage every half cycle. This function is called a memory function, and a discharge maintained at a low applied voltage based on this function is called a sustain discharge.

  In order to perform gradation display of an image in an AC type PDP, a subframe display for dividing an image signal of one field period into a plurality of subframes and controlling a time (number of times) to emit light by sustain discharge for each subframe. The method is adopted. Specifically, for example, a sustain discharge period that increases by a power of 2 is assigned to each subframe while resetting every frame. As a result, a cell having a larger number of sustain discharges emits light brighter, so that gradation display can be performed.

  A conventional display device using an AC type PDP for the display unit will be described below. FIG. 18 is a block diagram showing a conventional display device provided with an AC type PDP. As shown in FIG. 18, in the conventional display device 100 using the AC type PDP 101, a data driver circuit 102 a that is an integrated circuit for driving a column electrode (data electrode) is disposed at an end of the AC type PDP 101 in the column direction. Through 102e, and scan driver circuits 103a through 103c, which are integrated circuits for driving the row electrodes, are provided at the end of the AC type PDP 101 in the row direction. The conventional display device 100 includes a video signal processing circuit that converts and processes an input video signal, a drive signal generation circuit that outputs a drive signal in accordance with a synchronization signal, and a drive signal generation circuit. A high voltage drive circuit that supplies high voltage power to each data driver circuit based on the input drive signal is provided.

  Thus, in a display device using a display panel using a phosphor such as a PDP, when the same image is displayed for a long time, the phosphor characteristics change and burn-in occurs in a high-luminance part, and other images are displayed. Even when displayed, there is a problem that image sticking is conspicuous and the image quality is significantly impaired. Therefore, in conventional display devices, when an image that does not move, such as a still image, is displayed for a long time, the number of times of light emission is reduced, or the display position of the image is moved slightly every time the power is turned on or after a certain period of time has elapsed. Or by inverting the video signal to reduce damage to the phosphor (see, for example, Patent Documents 1 to 3). As a method of reducing the number of times of light emission, there are a method of reducing the number of sustain pulses as a whole in the long life mode, reducing the number of subfields, or doubling the light emission interval of the same pixel by interlace driving. For example, in the display device described in Patent Document 1, when a preset time is reached, a burn-in prevention circuit is activated to reduce the brightness of the display image or return the display image to a predetermined brightness. I'm trying to prevent it.

  Further, in the burn-in prevention circuit described in Patent Document 2, the image data is stored in the memory unit, and if there is no difference in the display image data even after a predetermined time has elapsed, the program read from the storage unit The display position of the image is moved by a predetermined number of pixels in the horizontal direction and the vertical direction. Further, the protection circuit described in Patent Document 3 reverses the polarity applied to the display unit when a state in which the display rate of the video signal is equal to or lower than a predetermined rate continues for a predetermined time. Such a burn-in prevention circuit or protection circuit is generally provided in a drive circuit or an image signal processing circuit.

Japanese Patent Laid-Open No. 9-266555 (page 4-8, FIG. 1-12) Japanese Patent No. 3454292 (Page 2, Fig. 1) JP-A-9-114418 (page 3, FIG. 1)

  However, the conventional techniques described above have the following problems. The method of reducing the number of times of light emission of the entire screen has problems that the display image becomes dark and the observer feels flickering in the display image (interlace driving). Further, the method of shifting the display position has an effect of blurring the boundary portion when burn-in occurs, but does not prevent the burn-in itself. Furthermore, the method of inverting the image signal has problems that it takes time to process and the driving efficiency is poor. As described above, the conventional image sticking prevention method has problems such as deterioration of image quality, and a sufficient effect is not obtained.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a display device and a display method capable of preventing image sticking without degrading the quality of a display image.

  The display device according to the first aspect of the present invention is a display device having a display unit for displaying an image and a drive circuit unit for driving the display unit, wherein the drive circuit unit performs the display on the input video signal. A burn-in prevention circuit for performing a burn-in prevention process for preventing image burn-in. The burn-in prevention circuit outputs a processing area control signal for designating a video area to be subjected to the burn-in prevention process in the entire display area. And a signal processing unit for performing a burn-in prevention process for a predetermined period of time on a video signal in a video region designated by the processing region control signal.

  The burn-in phenomenon in a PDP that performs color display occurs because a high-intensity signal that is fixed for a long time is displayed on a specific portion of the screen, and the phosphor in that portion burns. Therefore, not only a still image but also an image having the same screen configuration displayed repeatedly in units of time, day, or week causes burn-in. Therefore, the present inventors perform video signal processing that reduces burn-in only in video regions where burn-in is likely to occur when the screen configuration is known in advance or when the position for displaying time and captions is fixed. I found a way to do it.

  In the present invention, the drive circuit unit of the image display device designates or specifies the video area to be subjected to the burn-in prevention process, and performs the burn-in prevention process for a predetermined period on the image signal of the identified video area. In order to perform a burn-in prevention process only on a specific video area, an image having a high-luminance still image area is displayed on a display panel using a phosphor such as a PDP. Even when the image is displayed for a long time, the burn-in prevention process can be performed without degrading the quality of the display image.

  The display device according to the present invention includes a timer unit that sets a start time and an end time or a start time and a processing period of the burn-in prevention process, and the control unit includes a start time and an end time or a start time and a processing period of the timer unit. The process area control signal is output between the start time and the end time, and the signal processing unit inputs the process area control signal from the control unit while the burn-in process is performed. May be applied. Alternatively, it has a timer unit for setting the start time and end time or start time and processing period of the burn-in prevention process, and the control unit outputs the processing region control signal at the start time of the burn-in prevention process, and the signal The processing unit may input the processing area control signal from the control unit and then perform the burn-in process, and stop the burn-in process at the end time or after the processing period has elapsed. The timer unit can be provided in the burn-in prevention circuit.

  In the display device of the present invention, the control unit of the burn-in prevention circuit may be provided with a region setting unit that stores a video region to be subjected to burn-in prevention processing and outputs position data thereof. Or it has a storage part in which data of one or a plurality of mask patterns in which an opening is formed at a position corresponding to an image area to be subjected to a burn-in prevention process, and the control part stores the data in the storage part A pattern selection unit that selects one or a plurality of patterns from the mask patterns thus formed may be provided. As a result, it is possible to easily set the video area to be subjected to the burn-in prevention process.

  Further, as the burn-in prevention process performed in the signal processing unit, for example, a clip process for reducing a video signal with a higher luminance than a set value to a set value, a level of the video signal with a higher luminance is reduced at a certain rate Thus, it is possible to apply contrast compression processing for reducing the maximum luminance or luminance level reduction processing for reducing the level of the video signal at a constant rate.

  The display method according to the second aspect of the present invention is a display unit for displaying an image, a drive circuit unit for driving the display unit, and a burn-in of the display unit with respect to a video signal provided in the drive circuit unit. A display method of a display device having a burn-in prevention circuit for performing a burn-in prevention process for specifying a video area to be subjected to a burn-in prevention process in the entire display area from a control unit of the burn-in prevention circuit A step of outputting an area control signal; and a step of performing a burn-in prevention process for a predetermined period on a video signal in a video area specified by the processing area control signal in a signal processing unit of the burn-in prevention circuit. .

  According to the present invention, video areas that are likely to be burned in such as a time display area, a caption display area, and a high-luminance still image area are identified, and video signal processing is performed only on the identified areas. The burn-in of the display portion can be prevented without degrading the display image quality of the area.

  Hereinafter, a display device according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. First, a display device according to a first embodiment of the present invention will be described. FIG. 1 is a block diagram showing a display device of this embodiment. In FIG. 1, the same components as those of the conventional display device 100 shown in FIG. 18 are denoted by the same reference numerals, and detailed description thereof is omitted. In the display device 10 of the present embodiment, an AC type color PDP 101 is provided as a display panel in the display unit, and data driver circuits 102a to 102e are provided at the end of the AC type PDP 101 in the column direction. Scan driver circuits 103a to 103c are provided in the sections. The data driver circuits 102a to 102e are connected to column electrodes (data electrodes), and the scan driver circuits 103a to 103c are connected to row electrodes. In addition, the drive circuit unit includes a video signal processing circuit that converts and processes the input video signal, a drive signal generation circuit that outputs a drive signal to each circuit in response to a synchronization signal, and a drive signal generation circuit A high voltage drive circuit that supplies high voltage power to each data driver circuit based on the input drive signal is provided. Further, a burn-in prevention circuit is provided on the input side of the video signal processing circuit, and the video signal is input to the video signal processing circuit via the burn-in prevention circuit.

  Hereinafter, the burn-in prevention circuit will be described in detail. FIG. 2 is a block diagram showing the configuration of the burn-in prevention circuit in the display device of this embodiment. As shown in FIG. 2, the burn-in prevention circuit includes a video signal processing circuit 1, a time / region control circuit 2, and a programmable timer circuit 3. The video signal processing circuit 1 is arranged immediately after the video signal input terminal. Has been. FIG. 3 is a block diagram showing the configuration of the programmable timer circuit 3. As shown in FIG. 3, the programmable timer circuit 3 includes a time generation circuit, a time setting input circuit, and a timer control circuit such as a microprocessor. The programmable timer circuit 3 is set in advance with a display start time and a display end time of a video that is likely to be burned. When the same image is displayed every day or every week, the programmable timer circuit 3 can be set to operate at a predetermined time every day or every week, and can also be set to always operate. Then, the programmable timer circuit 3 outputs a time control signal to the time / region control circuit 2 at the set time.

  Next, the operation of the burn-in prevention circuit configured as described above will be described. In this burn-in prevention circuit, the input video signal and synchronization signal are output via the video signal processing circuit 1. In addition, the clock and the horizontal and vertical synchronization signals that serve as the reference of the video signal are also input to the time / region control circuit 2. Furthermore, when the preset time is reached, a time control signal is output from the programmable timer circuit 3 to the time / region control circuit 2, and in accordance with this time control signal, a processing region set in advance from the time / region control circuit 2 is output. A designated signal processing control signal G is output to the video signal processing circuit 1. The video signal processing circuit 1 performs signal processing such as clipping, contrast compression, or luminance level reduction on the input video signal only during a period in which the signal processing control signal G is input from the time / region control circuit 2.

  4A and 4B are waveform diagrams showing clip processing, FIG. 4A shows a video signal at the time of input, and FIG. 4B shows a video signal at the time of output. As shown in FIGS. 4A and 4B, the clipping process is a process of outputting a video signal that is equal to or higher than a predetermined value (clip level) to the clip level, and the clip level is constant at the peripheral pixel level. A value obtained by adding a value, a fixed level, or the like can be adopted.

  5A and 5B are waveform diagrams showing the contrast compression processing, FIG. 5A is a video signal at the time of input, and FIG. 5B is a video signal at the time of output. As shown in FIGS. 5A and 5B, the contrast compression process is a process of reducing the video signal level on the high luminance side at a constant rate and keeping the maximum luminance lower than the original video signal. As the compression method, various methods such as a method of preventing the decrease of the entire video signal level by making the waveform non-linear can be employed in addition to a method of decreasing the signal level at a constant rate. Note that it is not always necessary to compress the high luminance side. If the entire video signal is bright, the video signal level on the low luminance side may be increased.

  Further, FIGS. 6A and 6B are waveform diagrams showing luminance level reduction processing, FIG. 6A is a video signal at the time of input, and FIG. 6B is a video signal at the time of output. . As shown in FIGS. 6A and 6B, the brightness level reduction process is a process of subtracting a certain value from the input video signal to lower the brightness level, and has the effect of reducing burn-in in the high brightness region. There is. When this process is performed, the entire area becomes dark, but the relative luminance difference of the video is preserved.

  As described above, in the display device 10 of the present embodiment, the above-described processing is performed only during the period in which the signal processing control signal G is input from the time / region control circuit 2. For this reason, since the above-described processing is not performed for a period in which the signal processing control signal G is not input, that is, a signal in an area where no image sticking countermeasure is necessary, image burn-in is prevented without degrading the overall image quality. be able to.

  Next, the operation of the time / region control circuit 2 will be described. FIG. 7 is a block diagram showing the time / region control circuit 2. FIG. 8 is a block diagram showing the region setting input circuit, and FIG. 9 is a diagram showing the operation of the region setting input circuit. First, a processing area setting method will be described. When setting a processing region, a signal processing range (a range where burn-in is expected to occur) is designated by an input device such as a rotary encoder and a push button switch. Specifically, as shown in FIG. 9, in the region setting input circuit of the time / region control circuit 2, the scanning line a is set as the start position and the scanning line b is set as the end position based on the vertical synchronization signal in the column direction. It is specified. On the other hand, in the row direction, the dot p is designated as the start position and the dot q is designated as the end position based on the horizontal synchronization signal. Thereby, a rectangular area in units of pixels is designated as the processing area. A plurality of signal processing areas can be set. As shown in FIG. 8, data relating to the processing area is input to a switch input editing circuit such as a microcomputer provided in the area setting input circuit, edited into setting data, and stored and held.

  In the display device 10 of the present embodiment, the signal processing control signal G is output from the time / region control circuit 2 even when the time control signal is not output from the programmable timer circuit 3 when the processing region is set. Thereby, the operator can visually confirm the range while inputting the processing range. In addition, the method of setting the processing area in the display device of the present embodiment is not limited to the above-described method. For example, as the input device, various devices capable of human interface, such as a mouse and a touch panel, are used. Can be used. Further, the shape of the processing area does not have to be a rectangle, may be matched with a shape in which image sticking occurs, and by adding a circuit, a more complicated shape can be specified by a bitmap or the like.

  Next, a method for outputting the signal processing control signal G based on the set processing region data will be described. As shown in FIG. 7, the block selection signal, the setting mode signal, the horizontal range signal, and the vertical range signal output from the region setting input circuit 5 are input to the two-dimensional region specifying circuits 4a, 4b, and 4c. FIG. 10 is a block diagram showing the two-dimensional area designating circuit 4. The two-dimensional area designating circuit 4 designates the decode value and the designating circuit itself based on each input signal. Specifically, for the horizontal section of the processing area, the start position and end position are decoded from the value of the horizontal counter, and a horizontal timing pulse is generated by the set / reset flip-flop. Similarly, in the vertical section of the processing area, the start position and the end position are decoded from the value of the vertical counter, and the timing pulse in the vertical direction is generated by the set / reset flip-flop. Then, by taking these two logical products, a signal processing control signal G1 corresponding to the processing region set in the region setting input circuit is obtained. As shown in FIG. 7, when a plurality of two-dimensional area specifying circuits are provided, the signal processing control signals obtained by the respective circuits are synthesized by logical sum. The logical product of the signal processing control signal G1 and the time control signal output from the programmable timer circuit 3 is output as the final signal processing control signal G.

  Thus, when a time control signal is input from the programmable timer circuit 3 at the set time, the video signal processing control signal G corresponding to the set processing area is output to the video signal processing circuit 1 only during the set period. . FIG. 11 is a diagram showing the waveform of the control signal and the shape of the processing region at that time. From the time / region control circuit 2, a control signal corresponding to the shape of the processing setting region 6 is output from the screen display range 7 as the video signal processing control signal G. Specifically, as shown in FIG. 11, for example, control signals having different levels in the signal processing area and the other areas are input to the scanning line a and the scanning line b, respectively.

  12A is a schematic diagram showing a display image before the burn-in process, FIG. 12B is a schematic diagram showing a display image during processing area setting, and FIG. 12C is in operation of the burn-in prevention circuit. It is a schematic diagram which shows a display image. In FIG. 12C, the burn-in prevention process area is hatched to distinguish it from the process setting area. As described above, the display device according to the present embodiment includes the time display, subtitles, high-intensity still image, and the like shown in FIG. ), An area where time or subtitles are displayed and an area where burn-in is expected to occur such as a high brightness still image area is specified and registered in advance in the area setting input circuit 5 of the time / area control circuit 2 Keep it. Then, based on the position data of the process setting area 6 registered in the area setting input circuit 5 and the data of the process start and end times registered in the programmable timer circuit 3, the image of the area where occurrence of burn-in is predicted Only the signal is selectively subjected to video signal processing for preventing burn-in. Therefore, in the display device according to the present embodiment, as shown in FIG. 12C, the image signal in the portion other than the burn-in prevention process area 9 is not subjected to the burn-in prevention process, so that the deterioration in the quality of the display image is minimized. To the limit. As a result, the quality of the display image during the burn-in prevention process can be improved as compared with the case where the burn-in prevention process is performed on all video signals as in the conventional display device.

  In addition, since the display device 10 of the present embodiment does not need to change the structure, manufacturing method, driving method, and the like of the color PDP that is the display unit, the above-described burn-in prevention circuit is added to the video signal processing circuit of the conventional display device. It can also be manufactured by being incorporated or externally attached. In the display device of this embodiment, a burn-in prevention circuit is provided on the input side of the video signal processing circuit. This burn-in prevention circuit is provided on the output side of the video signal processing circuit and supplies a video signal to the PDP. The same processing can also be performed on the side.

  Next, a display device according to a second embodiment of the present invention will be described. FIG. 13 is a block diagram showing a configuration of a burn-in prevention circuit in the display device according to the second embodiment of the present invention. FIG. 14 is a block diagram showing the time / region control circuit 12. As shown in FIGS. 13 and 14, the display device according to the present embodiment includes a ROM in which a plurality of burn-in prevention mask pattern data that can correspond to a typical video signal is stored. The area control circuit 12 is provided with a mask pattern selection circuit 15. The configuration other than the time / region control circuit 12 in the display device of this embodiment is the same as that of the display device of the first embodiment described above.

  Next, the operation of the time / region control circuit 12 in the display device of this embodiment will be described. FIG. 15 is a block diagram illustrating the mask pattern selection circuit 15, and FIGS. 16A to 16C are diagrams illustrating mask patterns. FIG. 17 is a block diagram showing the two-dimensional area specifying circuit 14. In the time / area control circuit 12, for example, as shown in FIGS. 16A to 16C, a plurality of mask patterns in which openings are formed in the video area (processing setting area 8) to be subjected to the burn-in prevention process. One pattern is selected according to the display image by an input device such as a push button switch. Then, as shown in FIG. 15, the mask pattern selection circuit 15 edits the input mask pattern selection data by a switch editing circuit such as a microcomputer and outputs it as a mask pattern selection signal.

  As shown in FIG. 17, the mask pattern selection signal output from the mask pattern selection circuit 15 is input to the two-dimensional area designation circuit 14 together with the clock signal, the horizontal synchronization signal, and the vertical synchronization signal. The two-dimensional area designating circuit 14 reads the mask pattern data selected from the mask data memory (ROM) based on the mask pattern selection signal. As a result, the time / region control circuit 12 outputs a signal processing control signal G in accordance with the time control signal input from the programmable timer circuit 13. With such a configuration, although there may be some redundancy, the processing region setting operation is easier than the display device 10 of the first embodiment described above.

  In the display devices of the first and second embodiments described above, the programmable timer circuit is provided in the burn-in prevention circuit. However, the present invention is not limited to this, for example, connected to the display device. A time signal may be input to the time / region control circuit from a commercially available timer or the like. Further, in the display devices of the first and second embodiments described above, the burn-in prevention process is performed on a previously set area, but the present invention is not limited to this. For example, the input video signal For areas where there is no or little change in the image, a circuit that outputs the position data to the video signal processing circuit is provided to prevent burn-in in areas other than the preset area as necessary. Processing can be performed.

It is a block diagram which shows the display apparatus of 1st Embodiment of this invention. It is a block diagram which shows the structure of the burn-in prevention circuit in the display apparatus of 1st Embodiment of this invention. 3 is a block diagram showing a configuration of a programmable timer circuit 3. FIG. (A) And (b) is a wave form diagram which shows a clip process, (a) is a video signal at the time of input, (b) is a video signal at the time of output. (A) And (b) is a wave form diagram which shows contrast compression processing, (a) is a video signal at the time of input, (b) is a video signal at the time of output. (A) And (b) is a wave form diagram which shows a luminance level reduction process, (a) is a video signal at the time of input, (b) is a video signal at the time of output. 3 is a block diagram showing a time / region control circuit 2. FIG. 3 is a block diagram showing a region setting input circuit 5. FIG. FIG. 6 is a diagram illustrating an operation of a region setting input circuit 5. 3 is a block diagram showing a two-dimensional area specifying circuit 4. FIG. It is a figure which shows the waveform of a control signal, and a process area | region shape. (A) is a schematic diagram showing a display image before burn-in processing, (b) is a schematic diagram showing a display image during processing region setting, and (c) is a schematic diagram showing a display image during operation of the burn-in prevention circuit. FIG. It is a block diagram which shows the structure of the burn-in prevention circuit in the display apparatus of the 2nd Embodiment of this invention. 3 is a block diagram showing a time / region control circuit 12. FIG. 3 is a block diagram showing a mask pattern selection circuit 15. FIG. (A) thru | or (c) are figures which show a mask pattern. 3 is a block diagram showing a two-dimensional area designating circuit 14. FIG. It is a block diagram which shows the conventional display apparatus provided with AC type color PDP.

Explanation of symbols

1, 11; video signal processing circuits 2, 12; time / region control circuits 3, 13; programmable timer circuits 4, 4a to 4c, 14; two-dimensional region designation circuit 5; region setting input circuits 6, 8; 7; screen display range 9; burn-in prevention processing areas 10 and 100; display device 15; mask pattern selection circuit 101; AC type PDP panels 102a to 102e; data driver circuits 103a to 103c;

Claims (17)

In a display device having a display unit for displaying an image and a drive circuit unit for driving the display unit, the drive circuit unit prevents burn-in for preventing burn-in of the display unit with respect to an input video signal. A burn-in prevention circuit for performing processing, and the burn-in prevention circuit includes a control unit for outputting a processing area control signal for designating a video area to be subjected to the burn-in prevention process in the entire display area, and the processing area control signal. And a signal processing unit that performs a burn-in prevention process on a video signal in a designated video region for a predetermined period. It has a timer unit that sets the start time and end time or start time and processing period of the burn-in prevention process, and the control unit inputs a signal indicating the start time and end time or start time and processing period of the timer unit. The processing region control signal is output between the start time and the end time, and the signal processing unit performs the burn-in processing while inputting the processing region control signal from the control unit. The display device according to claim 1. A timer unit that sets a start time and an end time or a start time and a processing period of the burn-in prevention process, and the control unit outputs the processing region control signal at the start time of the burn-in prevention process, and the signal processing unit The burn-in process is performed after the processing area control signal is input from the control unit, and the burn-in process is stopped at the end time or after the processing period has elapsed. Display device. The display device according to claim 2, wherein the timer unit is provided in the burn-in prevention circuit. 5. The control unit according to claim 1, wherein the control unit is provided with a region setting unit that stores a video region to be subjected to burn-in prevention processing and outputs position data thereof. 6. Display device. A storage unit storing data of one or a plurality of mask patterns in which openings are formed at positions corresponding to video regions to be subjected to burn-in prevention processing; and the control unit stores the data in the storage unit The display device according to claim 1, further comprising a pattern selection unit that selects one or more patterns from the mask patterns. 7. The burn-in prevention process performed by the signal processing unit is a clip process for reducing a video signal having a luminance higher than a set value to a set value. Display device. 7. The burn-in prevention process performed by the signal processing unit is a contrast compression process for reducing the maximum brightness by reducing the level of a high brightness video signal at a constant rate. The display device according to any one of the above. 7. The display device according to claim 1, wherein the burn-in prevention process performed by the signal processing unit is a luminance level reduction process for reducing the level of the video signal at a constant rate. 8. . A display unit for displaying an image, a drive circuit unit for driving the display unit, and a burn-in prevention process for performing a burn-in prevention process to prevent the display unit from being burned into the input video signal provided in the drive circuit unit A display method of a display device comprising: a process for outputting a processing area control signal for designating a video area to be subjected to a burn-in prevention process in the entire display area from the control unit of the burn-in prevention circuit; and And a step of performing a burn-in prevention process for a predetermined period on the video signal of the video area specified by the processing area control signal in the signal processing unit of the burn-in prevention circuit. The timer unit has a step of setting the start time and end time or start time and processing period of the burn-in prevention process, and the control unit inputs a signal indicating the start time and end time or start time and processing period of the timer unit. Then, the processing region control signal is output between the start time and the end time, and the signal processing unit performs the burn-in process while the processing region control signal is input from the control unit. The display method according to claim 10. A step of setting a start time and an end time or a start time and a processing period of the burn-in prevention process in the timer unit, and the control unit outputs the processing region control signal at the start time of the burn-in prevention process, and the signal The processing unit, after inputting the processing region control signal from the control unit, performs the burn-in process, and stops the burn-in process at the end time or after the processing period has elapsed. Display method of description. 13. The controller according to claim 10, further comprising an area setting unit, wherein the area setting unit stores an area on which the burn-in prevention process is performed and outputs position data thereof. Display method described in. The control unit is provided with a pattern selection unit. In the pattern selection unit, one or more openings are formed at positions corresponding to video areas to be subjected to the burn-in prevention process stored in the storage unit. The display method according to claim 10, wherein one or a plurality of patterns are selected from the mask patterns. 15. The display according to claim 10, wherein the signal processing unit performs a clip process for reducing a video signal having a luminance higher than a set value to a set value as a burn-in prevention process. Method. 15. The signal processing unit according to claim 10, wherein the signal processing unit performs a contrast compression process for reducing the maximum luminance by reducing the level of the high-luminance video signal at a constant rate as the burn-in prevention process. The display method according to Item 1. The display method according to claim 10, wherein the signal processing unit performs a luminance level reduction process for reducing the level of the video signal at a constant rate as the burn-in prevention process.

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