JP6202892B2 - Display device - Google Patents

Description

  The present invention adds an additional value to the gradation value of each pixel of the one frame based on the gradation value change between one frame of the pixel row to be displayed and the immediately preceding frame immediately before the one frame. The present invention relates to a display device that performs overdrive processing.

  In order to improve the response speed of the liquid crystal, a so-called overdrive process is widely used. Specifically, the overdrive process is to obtain a difference between the pixel value of the immediately preceding frame and the pixel value of the current frame, and drive the liquid crystal with a value obtained by adding a so-called overdrive amount according to the difference. .

  In relation to the overdrive processing, for example, Patent Document 1 discloses a liquid crystal display device that can effectively compensate for dynamic capacitance and effectively improve the quality of a stop image and / or a moving image. Has been.

  Further, Patent Document 2 discloses an image display device that can suppress a phenomenon in which a noise component or a temporally isolated point is emphasized by overdrive processing and improve image quality degradation such as flickering when using overdrive processing. ing.

JP 2012-93790 A JP 2011-164429 A

  On the other hand, as described above, in the overdrive process, the gradation value of the current frame to be displayed is compared with the gradation value of the immediately preceding frame, and a predetermined overdrive amount is added according to the change of the gradation value. More specifically, a positive overdrive amount is added to a pixel whose gradation value has increased compared to the previous frame, and a pixel of the current frame is added to a pixel whose gradation value has decreased. The response speed of the liquid crystal is improved by adding a negative overdrive amount to the adjustment value and inputting a value obtained by adding the overdrive amount.

  However, when the gradation value is in the range of 0 to 255, in the conventional overdrive processing, for example, the gradation value obtained by adding the overdrive amount exceeds the maximum value (255) or the minimum value (0). In this case, it cannot be input as it is, and is input as the maximum value or the minimum value. That is, in such a pixel, the overdrive amount is not correctly added.

  FIG. 14 is an explanatory diagram for explaining a problem when the conventional overdrive process is applied. In the current frame of the input image data (input image gradation value), in the case of the second pixel from the left in the drawing, the gradation value is changed from the gradation value “64” of the previous frame to “0”. When the overdrive processing is applied, the negative overdrive amount should be added to “0”, but in this case, the gradation value is lower than the minimum value, so the gradation value after the overdrive processing The driving is carried out with “post-processing gradation value” set to “0”. This also applies to the third pixel from the right in the drawing of FIG. (See arrow in Fig. 14)

  Thus, when the overdrive amount is not correctly added, there is a problem that the contrast of the displayed image is lowered, or a color image may look different. However, the liquid crystal display device of Patent Literature 1 and the image display device of Patent Literature 2 cannot solve such problems.

  The present invention has been made in view of such circumstances, and an object of the present invention is to change a gradation value between one frame of a pixel column to be displayed and the immediately preceding frame immediately before the one frame. Based on this, in a display device that performs an overdrive process for adding an additional value to the gradation value of each pixel of the one frame, the gradation value obtained by adding the additional value to the target pixel is the first. It is determined whether the threshold value is exceeded or the second threshold value lower than the first threshold value is not reached, and when it is determined that the first threshold value is exceeded or the second threshold value is not reached, Added during overdrive processing by calculating the excess exceeding 1 threshold or the shortage up to the second threshold and reflecting the excess or shortage on the neighboring pixels of the target pixel Value (overdrive amount) added Therefore gradation value obtained is to provide a display device capable of preventing the problems caused by the the additional value can not be correctly added from exceeding a predetermined threshold.

  Another object of the present invention is to change the gradation value between one frame of a pixel column to be displayed and the immediately preceding frame immediately before the one frame, for each pixel of the one frame. In a display device that performs an overdrive process for adding an additional value to a gradation value, a reached gradation value that can actually be reached is calculated based on the processed gradation value obtained by the overdrive process for the pixel of interest, and By subtracting the reached gradation value from the gradation value of the pixel of interest and reflecting the result of the subtraction on the adjacent pixels of the pixel of interest, an additional value (overdrive amount) can be obtained during overdrive processing. An object of the present invention is to provide a display device capable of preventing problems caused by the fact that the additional value is not added correctly because the gradation value obtained by the addition exceeds a predetermined threshold value.

  The display device according to the present invention adds to the gradation value of each pixel of the one frame based on the gradation value change between one frame of the pixel row to be displayed and the immediately preceding frame immediately before the one frame. In a display device that performs an overdrive process for adding a value, a gradation value obtained by adding the additional value to a target pixel exceeds a first threshold value or is lower than the first threshold value. Determining means for determining whether or not two threshold values have been reached, and when the determining means determines that the first threshold value is exceeded or the second threshold value has not been reached, the excess value exceeding the first threshold value, or the It is characterized by comprising a calculating means for calculating the shortage up to the second threshold and a reflecting means for reflecting the excess or shortage to the neighboring pixels of the target pixel.

  The display device according to the present invention adds to the gradation value of each pixel of the one frame based on the gradation value change between one frame of the pixel row to be displayed and the immediately preceding frame immediately before the one frame. In a display device that performs an overdrive process for adding a value, an arrival value calculation unit that calculates an reached gradation value that can actually be reached based on a post-process gradation value obtained by the overdrive process for a target pixel; and Subtracting means for subtracting the reached gradation value from the gradation value of the target pixel; and reflecting means for reflecting the subtraction result of the subtracting means to adjacent pixels of the target pixel.

  The display device according to the present invention is characterized in that the reflecting means performs the reflection on the pixel to be overdriven after the pixel of interest.

  In the display device according to the present invention, the reflection means is configured to perform the reflection on adjacent pixels in the moving direction of the moving object when the image related to the one frame is a moving image. And

  The display device according to the present invention is characterized in that the reflecting means is configured to perform the reflection on both pixels sandwiching the pixel of interest in the one frame.

  The display device according to the present invention reflects the reflection on a pixel corresponding to the target pixel in the immediately preceding frame and a pixel corresponding to the target pixel in the immediately following frame to be processed immediately after the one frame. It is comprised so that it may perform.

  The display device according to the present invention is configured such that the subtraction result of the subtraction unit is corrected according to a use temperature, and the reflection unit performs the reflection using the corrected subtraction result of the subtraction unit. It is characterized by that.

  According to the present invention, during the overdrive process, the gradation value obtained by adding the additional value exceeds a predetermined threshold value, and therefore, the additional value is not added correctly. It is possible to prevent the color image from being lowered or appearing in a color image.

It is a functional block diagram which shows the principal part structure of the display apparatus 1 which concerns on Embodiment 1 of this invention. It is an illustration figure which shows an example of the look-up table used in the display apparatus 1 which concerns on Embodiment 1 of this invention. FIG. 3 is a functional block diagram illustrating a main configuration of a control unit 10 in the display device 1 according to Embodiment 1 of the present invention. 6 is a flowchart illustrating correction of overdrive processing in the display device 1 according to Embodiment 1 of the present invention. It is an illustration figure explaining the result of amendment of overdrive processing in display 1 concerning Embodiment 1 of the present invention. It is a functional block diagram which shows the principal part structure of the control part 10 in the display apparatus 1 which concerns on Embodiment 2 of this invention. It is an illustration figure which shows an example of an arrival value table and an excess and deficiency table. It is a flowchart explaining correction | amendment of the overdrive process in the display apparatus 1 which concerns on Embodiment 2 of this invention. It is a functional block diagram which shows the principal part structure of the control part 10 in the display apparatus 1 which concerns on Embodiment 2 of this invention. It is an illustration figure explaining the result of amendment of overdrive processing in display 1 concerning Embodiment 3 of the present invention. FIG. 6 is an exemplary diagram illustrating a case where only overdrive processing is performed and correction according to the present invention is not performed. It is a functional block diagram which shows the principal part structure of the display apparatus 1 which concerns on Embodiment 4 of this invention. It is a functional block diagram which shows the principal part structure of the control part 10 in the display apparatus 1 which concerns on Embodiment 4 of this invention. It is explanatory drawing explaining the problem in the case of applying the conventional overdrive process.

  Hereinafter, a display device according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a functional block diagram showing a main configuration of a display device 1 according to Embodiment 1 of the present invention.

  A display device 1 according to Embodiment 1 of the present invention includes a liquid crystal panel 100, a gate line driving circuit 90 that drives the gate lines of the liquid crystal panel 100, a storage unit 20 that can store a plurality of image data for one frame, a floor A voltage generation circuit 70 for generating a regulated voltage, a data line driving circuit 50 for driving the data lines of the liquid crystal panel 100, a data line driving circuit 50, and a clock signal for instructing display timing are output to the gate line driving circuit 90. A clock 80, an overdrive correction processing unit 40 that performs overdrive processing on the gradation value of each pixel of a frame to be displayed, a frame to be processed by the overdrive correction processing unit 40, and a frame that stores a frame immediately before the frame Setting instruction of gradation voltage to memory 60 and voltage generation circuit 70, and image display timing to clock 80 And a control unit 10 for instructing the like grayed.

  Hereinafter, for convenience of explanation, when a predetermined image is displayed from input image gradation values (0 to 255) of a plurality of frames, overdrive processing should be actually performed by the overdrive correction processing unit 40 among the plurality of frames. A frame is called a current frame (one frame), a frame immediately before the current frame is called a previous frame, and a frame immediately after the current frame is called a next frame.

  The case where the current frame is overdriven is referred to as the current frame after processing, the case where the immediately preceding frame is overdriven is referred to as the immediately preceding frame after processing, and the case where the immediately following frame is overdriven is processed. It is called a frame immediately after.

  Here, the overdrive processing compares the gradation value of the current frame with the gradation value of the immediately preceding frame, and a predetermined overdrive amount (hereinafter referred to as an additional value) according to the change of the gradation value. ). More specifically, for a pixel whose gradation value has increased compared to the previous frame, a predetermined additional value (positive) is added to the gradation value of the current frame, and the liquid crystal panel is driven by a higher liquid crystal driving voltage. For a pixel whose gradation value is reduced, a predetermined additional value (negative) is added to the gradation value of the current frame to drive the liquid crystal panel with a lower liquid crystal driving voltage. is there. Thereby, the response speed of the liquid crystal panel 100 can be increased.

The overdrive correction processing unit 40 receives the current frame data Fn input from the storage unit 20 and the previous frame data Fn−1 input from the frame memory 60. And a change in gradation between the two image data is detected. Further, the overdrive correction processing unit 40 performs the overdrive processing as described above with reference to the lookup table.

  FIG. 2 is an exemplary diagram showing an example of a lookup table used in the display device 1 according to Embodiment 1 of the present invention. In the lookup table, the horizontal axis represents the gradation value of the immediately preceding frame, and the vertical axis represents the gradation value of the current frame. The overdrive correction processing unit 40 selects the gradation value corresponding to the combination of gradations between the data Fn of the current frame and the data Fn-1 of the previous frame, and the gradation value of the target pixel of the current frame is selected. A current frame is generated after the processing replaced with the gradation value.

  The frame memory 60 includes an n frame memory 62 and an n−1 frame memory 61. The n frame memory 62 stores the current frame and the processed current frame, and the n−1 frame memory 61 stores the corrected current frame obtained by performing the correction described later on the processed current frame. . That is, display based on the corrected current frame is performed, the next frame is read as the current frame from the storage unit 20, and the corrected current frame is stored in the n−1 frame memory 61.

  The storage unit 20 is configured by a nonvolatile storage medium such as flash memory, EEPROM (registered trademark), HDD, MRAM (magnetoresistance memory), FeRAM (ferroelectric memory), or OUM, for example. The image data (gradation value) to be displayed on the liquid crystal panel 100 is stored.

  The data line driving circuit 50 sequentially receives the corrected current frames output from the frame memory 60, latches image data for one frame, and generates the voltage generation circuit 70 according to the clock signal instructed from the clock 80. A voltage selected according to image data from the gradation voltage is applied to the liquid crystal panel 100. Further, the gate line driving circuit 90 applies a gate pulse to the liquid crystal panel 100 in accordance with a clock signal instructed from the clock 80 to drive the liquid crystal panel 100.

  FIG. 3 is a functional block diagram showing the main configuration of the control unit 10 in the display device 1 according to Embodiment 1 of the present invention. The control unit 10 includes a CPU 11, a ROM 12, a RAM 13, a determination unit 14, a calculation unit 15, and a reflection unit 16.

  The ROM 12 stores in advance fundamentally fixed data among various control programs and calculation parameters, and the RAM 13 temporarily stores the data and reads it regardless of the storage order, storage position, etc. Is possible. The RAM 13 stores, for example, a program read from the ROM 12, various data generated by executing the program, parameters that change as appropriate during the execution, and the like.

  The CPU 11 loads the control program stored in advance in the ROM 12 onto the RAM 13 and executes it, thereby controlling the various hardware described above and operating the entire device as the display device 1 of the present invention. Further, the control unit 10 corrects the overdrive process as described below. This will be described in detail below.

  As already described, among the gradation values of each pixel in the current frame, the floor corresponding to or near the highest value (255) (first threshold value) or the lowest value (0) (second threshold value). Tone values cannot be added with additional values like other pixels. As shown in FIG. 14, in the current frame before the overdrive process, the pixels whose input image gradation values are “0” and “255” are added values (“+16” or “ When “−16”) is added, the result is below the minimum value or above the maximum value, respectively. However, since an image cannot be displayed based on such a gradation value, the gradation value of the pixel is set to the lowest value or the highest value in the current frame after the actual overdrive processing (current frame after the processing). ing.

  In such a case, there is a problem that the contrast of the image displayed on the liquid crystal panel 100 is lowered, or the color image may appear different.

  On the other hand, in the display device 1 according to the first embodiment of the present invention, only the part of the additional value that cannot be added to the target pixel is added to the adjacent pixel of the target pixel.

  That is, in the overdrive process for each pixel of the current frame, the determination unit 14 determines whether the gradation value exceeds the maximum value or less than the minimum value when the additional value is added. To do.

  For example, when the determination unit 14 determines that the gradation value exceeds the maximum value or less than the minimum value, the calculation unit 15 calculates the amount that could not be added to the target pixel. In the example of FIG. 14, in the gradation values “0” and “255”, the portions that cannot be added to the target pixel are “−16” and “+16”, respectively. Hereinafter, the amount that cannot be added to the pixel of interest and that exceeds the maximum value is referred to as the excess, and the amount that is less than the minimum value, in other words, the amount that is insufficient to the minimum value. The shortage.

  In this way, when the excess or deficiency is calculated by the calculation unit 15, the reflection unit 16 reflects the excess or deficiency on the adjacent pixel of the target pixel. That is, the reflection unit 16 adds the excess amount to the adjacent pixel of the target pixel or subtracts the shortage amount.

  FIG. 4 is a flowchart for explaining correction of overdrive processing in the display device 1 according to the first embodiment of the present invention. FIG. 5 is a flowchart of overdrive processing in the display device 1 according to the first embodiment of the present invention. It is an illustration figure explaining the result of amendment.

  FIG. 5 shows input image gradation values representing an image in which the moving object moves from the left to the right of the display screen. Frame 2 in FIG. 5 is the current frame, frame 1 is the immediately preceding frame, and frame 3 is the immediately following frame. This will be described as a frame.

  In FIG. 5, circles indicate pixels whose gradation value exceeds the maximum value or falls below the minimum value when the additional value is added as a result of overdrive processing. In FIG. 5, an ellipse is a pixel reflected by the reflection unit 16 with the excess or deficiency. That is, in the present embodiment, in the moving image, the reflection portion 16 reflects the excess or deficiency on adjacent pixels in the moving direction of the moving object.

  First, the gradation value for one frame is read from the storage unit 20 as the current frame (step S101), and the overdrive correction processing unit 40 performs overdrive processing on the gradation value of each pixel of the read current frame. This is performed (step S102). In this embodiment, an overdrive process is performed on the frame 2, and the frame 1 is stored in the n−1 frame memory 61. The overdrive processing is performed on each pixel in the current frame, for example, from the left to the right in the drawing.

  At this time, the determination unit 14 of the control unit 10 determines whether the gradation value when the additional value is added exceeds the maximum value or less than the minimum value (step S103). . The determination by the determination unit 14 is performed for each pixel.

  If the determination unit 14 determines that the gradation value when adding an additional value to the target pixel does not exceed the maximum value or less than the minimum value (step S103: NO), the process proceeds to step S106. .

  On the other hand, when the determination unit 14 determines that the gradation value when the additional value is added to the target pixel is greater than the maximum value or less than the minimum value (step S103: YES), the calculation unit 15 The amount that cannot be added to the pixel of interest, that is, the excess or deficiency is calculated (step S104). The calculation of excess or deficiency by the calculation unit 15 has already been described, and detailed description thereof will be omitted.

  Next, the reflection unit 16 reflects the excess or deficiency calculated by the calculation unit 15 in the moving direction of the moving object with respect to the target pixel in the current frame, that is, the adjacent pixel in the right direction in the drawing. (Step S105).

  For example, when the second pixel from the left of frame 2 in FIG. 5 is the target pixel, the gradation value of the target pixel is “0”, and an additional value is added during the overdrive process. The gradation value is less than the minimum value “0”. Accordingly, the calculation unit 15 calculates the deficiency related to the target pixel, and the deficiency is “−16”. Next, the reflecting unit 16 reflects the shortage “−16” on the adjacent pixel in the right direction in the drawing with respect to the target pixel.

  That is, the gradation value of the adjacent pixel in the right direction with respect to the target pixel has changed from “128” immediately before to “64”, and the gradation after overdrive processing is based on the lookup table of FIG. The value should be “48”. However, in the display device 1 according to the present invention, since the deficient “−16” is reflected as described above, the gradation value of the pixel after correction is “32”.

  Thereafter, the CPU 11 determines whether or not the overdrive process and the above-described correction for all the pixels in the current frame are completed (step S106).

  If the CPU 11 determines that the overdrive process for all the pixels in the current frame and the above correction are not completed (step S106: NO), the process returns to step S102. Thereafter, the overdrive process and the above-described correction are performed on the pixel on the right side of the target pixel.

  When the CPU 11 determines that the overdrive processing and the above correction have been completed for all the pixels of the current frame (step S106: YES), the corrected current frame (corrected current frame) obtained by the overdrive processing and the above correction is determined. ) Is output to the data pre-drive circuit 50 and stored in the n-1 frame memory 61 of the frame memory 60 (step S107). Thereafter, the process ends.

  FIG. 5 shows a gradation value (hereinafter referred to as a corrected gradation value) obtained by performing the overdrive process and the above correction on the frame 1 and the frame 2, and a liquid crystal based on the corrected gradation value. The gradation values of the actual liquid crystal panel when an image is displayed on the panel 100 are shown.

The gradation value of the liquid crystal panel according to the embodiment is obtained by the following formula, for example.
Tone value of liquid crystal panel of implementation = Y + (Z−Y) × 0.8
Here, Y is the value of the pixel in the immediately preceding frame corresponding to the target pixel, and Z is the corrected gradation value corresponding to the target pixel.

  For example, in the three pixels on the left side of the frame 2 as viewed in the drawing, the actual gradation values of the liquid crystal panel are “64”, “13”, and “51”, respectively, and the average is “42.6”. On the other hand, the input image gradation values of the three pixels are “64”, “0”, and “64”, respectively, the average is “42.6”, and the actual gradation value of the liquid crystal panel. Are the same.

  When an image is viewed with the human eye, it is averaged with the tone values of adjacent pixels, so that after the processing according to the present invention, it is similar to the target input image tone value compared to the case of only overdrive processing Looks like to do.

  In the above description, the case where the reflection portion 16 reflects the excess or deficiency on adjacent pixels in the moving direction of the moving object has been described as an example, but the present invention is not limited to this. For example, the excess or deficiency may be reflected on adjacent pixels in the direction opposite to the direction in which the moving object moves.

  Note that the determination unit 14, the calculation unit 15, and the reflection unit 16 described above may be configured by hardware logic, or may be constructed in software by the CPU 11 executing a predetermined program.

(Embodiment 2)
In the first embodiment, when overdrive processing is performed on each pixel of the current frame, an excess or deficiency when an additional value is added is calculated, and the excess or deficiency is calculated as an adjacent pixel of the target pixel. The problem that the above-mentioned problem in the overdrive process is solved by reflecting the above in the above has been described. In the second embodiment of the present invention, this problem is solved by a different method.

  The display device 1 according to the second embodiment of the present invention has the same configuration as that of the first embodiment, but differs in the configuration of the control unit 10.

  FIG. 6 is a functional block diagram showing a main configuration of the control unit 10 in the display device 1 according to Embodiment 2 of the present invention. The control unit 10 includes a CPU 11, a ROM 12, a RAM 13, an arrival value calculation unit 17, a subtraction unit 18, and a reflection unit 19.

  The arrival value calculation unit 17 has an arrival value table (see FIG. 7), and uses the arrival value table to calculate an arrival value for each pixel of the current frame. Here, the reached value is a gradation that can be actually reached when the overdrive processing is performed on each pixel of the current frame and display is performed on the liquid crystal panel 100 based on the processed gradation value obtained thereby. Value.

  The subtraction unit 18 subtracts the corresponding arrival value calculated by the arrival value calculation unit 17 from the gradation value of each pixel in the current frame, and calculates the difference between the gradation value of each pixel in the current frame and the arrival value. Ask. That is, such a difference actually corresponds to a shortage that has not reached the gradation value of the current frame, or an excess that has exceeded the gradation value of the current frame. The subtraction unit 18 may perform such subtraction each time, and has a subtraction result as a table (hereinafter referred to as an excess / deficiency table) in advance, and the subtraction result is obtained based on the excess / deficiency table. You may comprise so that it may obtain (refer FIG. 7).

  The reflecting unit 19 reflects the subtraction result obtained by the subtracting unit 18 on the corresponding pixel of the current frame. The reflection unit 19 adds the subtraction result (absolute value) to an adjacent pixel of the target pixel when the subtraction result is positive, or applies to the adjacent pixel of the target pixel when the subtraction result is negative. Subtract the subtraction result (absolute value).

  FIG. 7 is an exemplary diagram showing an example of the above-described reached value table and excess / deficiency table. FIG. 7A is a table of gradation values of the current frame, FIG. 7B is an arrival value table, and FIG. 7C is an excess / deficiency table. Hereinafter, as described above, the description will be made on the assumption that “the gradation value of the liquid crystal panel according to the embodiment = Y + (Z−Y) × 0.8”.

In order to match the actual gradation value of the liquid crystal panel, in other words, the transmittance of the liquid crystal panel with the gradation value (X) of the current frame,
X = Y + (Z−Y) × 0.8
Therefore, the gradation value (Z) after the processing by the overdrive processing (see FIG. 2)
Z = 1.25X−0.25Y = Y + (XY) × 1.25
255 for Z> 255
0 if Z <0
And it is sufficient.

And the reached value and excess and deficiency are
Achieving value = Y + (Z−Y) × 0.8
Deficiency = X-reached value.

  The reached values and excess / deficiency obtained by the above method are shown in FIG. 7 (B) arrival value table and (C) excess / deficiency table, respectively.

  FIG. 8 is a flowchart for explaining correction of overdrive processing in the display device 1 according to Embodiment 2 of the present invention.

  First, the gradation value for one frame is read from the storage unit 20 as the current frame (step S201), and the overdrive correction processing unit 40 performs overdrive processing on the gradation value of each pixel of the read current frame. This is performed (step S202). The overdrive process is performed on the current frame, for example, from the left to the right in the drawing.

  At this time, the reaching value calculation unit 17 calculates the reaching value for the target pixel using the reaching value table or by calculation (step S203). The process of calculating the arrival value by the arrival value calculation unit 17 has already been described, and a detailed description thereof will be omitted.

  Next, the subtraction unit 18 subtracts the corresponding arrival value calculated by the arrival value calculation unit 17 from the gradation value of the pixel of interest in the current frame, and the gradation value of the pixel of interest in the current frame and the arrival value Is obtained (step S204). Such subtraction processing by the subtraction unit 18 has already been described, and detailed description thereof will be omitted.

  Next, the reflection unit 19 reflects the subtraction result obtained by the subtraction unit 18 on the adjacent pixel in the right direction in the drawing with respect to the target pixel in the current frame, for example, as in the first embodiment (step S205). .

  Thereafter, the CPU 11 determines whether or not the overdrive process and the above-described correction for all the pixels of the current frame are completed (step S206).

  If the CPU 11 determines that the overdrive processing for all the pixels in the current frame and the above correction have not been completed (step S206: NO), the CPU 11 returns the processing to step S202. Thereafter, the overdrive process and the above-described correction are performed on the pixel on the right side of the target pixel.

  When the CPU 11 determines that the overdrive processing and the above correction have been completed for all the pixels of the current frame (step S206: YES), the corrected current frame (corrected current frame) obtained by the overdrive processing and the above correction is determined. ) To the data line driving circuit 50 and stored in the n-1 frame memory 61 of the frame memory 60 (step S207). Thereafter, the process ends.

  The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The reached value calculation unit 17, the subtraction unit 18, and the reflection unit 19 described above may be configured by hardware logic, or may be constructed in software by the CPU 11 executing a predetermined program.

  The present invention is not limited to this. You may comprise so that the difference of the gradation value and arrival value of the said attention pixel of the present flame | frame calculated | required by the subtraction part 18 may be correct | amended according to the operating temperature of the display apparatus 1. FIG. For such correction, the subtraction unit 18 may have an excess / deficiency table for each use temperature in advance, and the difference may be obtained based on the excess / deficiency table for each temperature.

(Embodiment 3)
In the first embodiment, the excess or deficiency calculated by the calculation unit 15 is used to indicate the direction in which the moving object moves relative to the target pixel in the current frame, that is, adjacent to the right in the drawing. Although the case of reflecting on a pixel has been described, the present invention is not limited to this. In the third embodiment of the present invention, the reflection process by the reflection unit 16 is different from the first embodiment.

  The display device 1 according to the third embodiment of the present invention has the same configuration as that of the first embodiment, but differs in the configuration of the control unit 10.

  FIG. 9 is a functional block diagram showing a main configuration of the control unit 10 in the display device 1 according to Embodiment 2 of the present invention. The control unit 10 includes a CPU 11, a ROM 12, a RAM 13, a determination unit 14, a calculation unit 15, and a reflection unit 16A.

  As in the first embodiment, the determination unit 14 determines whether the gradation value to which the additional value is added exceeds the maximum value or less than the minimum value. When the determination unit 14 determines that the gradation value to which the additional value has been added exceeds the maximum value or is below the minimum value, the calculation unit 15 cannot add to the target pixel, that is, the excess Calculate minutes and shortages.

  As described above, when the excess or deficiency is calculated by the calculation unit 15, the reflection unit 16A reflects the excess or deficiency on the adjacent pixel of the target pixel. In the present embodiment, the reflecting unit 16A adds the excess amount or subtracts the shortage amount to both adjacent pixels sandwiching the target pixel.

  More specifically, the reflection unit 16A reflects the excess or deficiency calculated by the calculation unit 15 by ½ on each of the adjacent pixels in the horizontal direction in the drawing with respect to the target pixel.

  FIG. 10 is an exemplary diagram for explaining the result of overdrive processing correction in the display device 1 according to Embodiment 3 of the present invention. FIG. 11 shows only the overdrive processing, and the correction according to the present invention is performed. It is an illustration figure which illustrates the case where it is not.

  10 will be described as the current frame, frame 1 as the immediately preceding frame, and frame 3 as the immediately following frame.

  In FIG. 10, a circle indicates a pixel whose gradation value exceeds the maximum value or is below the minimum value when the additional value is added as a result of the overdrive process. In FIG. 10, an ellipse is a pixel in which the excess or deficiency is reflected by the reflection unit 16A.

  For example, when the second pixel from the left of frame 2 in FIG. 10 is the target pixel, the gradation value of the target pixel is “0”, and an additional value is added during the overdrive process. The gradation value is less than the minimum value “0”. Therefore, the calculation unit 15 calculates the shortage related to the target pixel. In the present embodiment, the shortage is assumed to be “−20” for convenience of explanation.

  Next, the reflecting unit 16A reflects “−10” that is ½ of the shortage “−20” to the adjacent pixel in the horizontal direction in the drawing with respect to the target pixel.

  That is, with respect to the target pixel, the gradation value of the adjacent pixel in the left direction changes from “0” immediately before to “64”, and the gradation value of the adjacent pixel in the right direction changes to “128”. "" To "64". Therefore, the gradation values after the overdrive processing should be “80” and “48” in the left direction and the right direction, respectively, based on the lookup table of FIG. However, in the display device 1 according to the present invention, as described above, each of the two pixels after correction according to the present invention is reflected in each pixel by “−10” which is ½ of the shortage. The gradation values are “70” and “38”.

  When such correction processing is performed, for example, in the three pixels on the left side of the frame 2 in the drawing, the actual gradation values of the liquid crystal panel are “56”, “13”, and “56”, respectively. The average is “41.6”. On the other hand, the input image gradation values of the three pixels are “64”, “0”, and “64”, respectively, the average is “42.6”, and the average value of the actual gradation values of the liquid crystal panel And approximate.

  On the other hand, when only the overdrive processing is performed and the correction according to the present invention is not performed (see FIG. 11), the actual liquid crystal panel gradation values in these three pixels are “64”, “ 13 ”and“ 64 ”, and the average is“ 47 ”, which is greatly different from the average value“ 42.6 ”of the three pixels of the input image gradation value.

  When an image is viewed with the human eye, it is averaged with the tone values of adjacent pixels, so that after the processing according to the present invention, it is similar to the target input image tone value compared to the case of only overdrive processing Looks like to do.

  The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  Note that the determination unit 14, the calculation unit 15, and the reflection unit 16 </ b> A described above may be configured by hardware logic, or may be constructed in software by the CPU 11 executing a predetermined program.

(Embodiment 4)
In the first embodiment, the excess or deficiency calculated by the calculation unit 15 is used to indicate the direction in which the moving object moves relative to the target pixel in the current frame, that is, adjacent to the right in the drawing. Although the case of reflecting on a pixel has been described, the present invention is not limited to this. In the fourth embodiment of the present invention, the reflection process by the reflection unit is different from the first embodiment.

  FIG. 12 is a functional block diagram showing the main configuration of the display device 1 according to Embodiment 4 of the present invention. As in the case of the first embodiment, the display device 1 according to the fourth embodiment of the present invention includes the liquid crystal panel 100, the gate line driving circuit 90, the storage unit 20, the voltage generation circuit 70, the data line driving circuit 50, the clock. 80, an overdrive correction processing unit 40, a frame memory 60, and a control unit 10.

  Furthermore, the display device 1 according to Embodiment 4 of the present invention includes a next frame changing unit 30. The next frame changing unit 30 has an n + 1 frame memory 31 and stores a frame immediately after the current frame.

  Further, the next frame changing unit 30 performs a process of reflecting the excess or the shortage calculated by the calculation unit 15 on the immediately following frame in response to an instruction from the reflection unit 16B described later. The frame immediately after such processing is set as the target of the overdrive processing as the current frame.

  In the fourth embodiment of the present invention, the frame memory 60 is configured to output the frame immediately before correction to the data line driving circuit 50. Here, the immediately preceding frame is a frame after the immediately preceding frame is corrected according to the overdrive process and the present invention.

  In other words, in the fourth embodiment of the present invention, the corrected current frame is output to the data line driving circuit 50 instead of being stored in the frame memory 60 after being output to the data line driving circuit 50. Instead, it is replaced as a frame immediately before correction and stored in the n-1 frame memory 61. The frame immediately before correction is output to the data line driving circuit 50 after overdrive processing for the current frame and correction according to the present invention, that is, after the corrected current frame is generated.

  The display device 1 according to Embodiment 4 of the present invention has the same configuration as that of Embodiment 1, but differs in the configuration of the control unit 10.

  FIG. 13 is a functional block diagram showing a main configuration of the control unit 10 in the display device 1 according to Embodiment 4 of the present invention. The control unit 10 includes a CPU 11, a ROM 12, a RAM 13, a determination unit 14, a calculation unit 15, and a reflection unit 16B.

  As in the first embodiment, the determination unit 14 determines whether the gradation value to which the additional value is added exceeds the maximum value or less than the minimum value. When the determination unit 14 determines that the gradation value to which the additional value has been added exceeds the maximum value or is below the minimum value, the calculation unit 15 cannot add to the target pixel, that is, the excess Calculate minutes and shortages.

  In this way, when the excess or deficiency is calculated by the calculation unit 15, the reflection unit 16B reflects the excess or deficiency on the adjacent pixel of the target pixel. In the present embodiment, the reflection unit 16B adds the excess to the pixel corresponding to the target pixel in the immediately preceding frame and the pixel corresponding to the target pixel in the immediately following frame, or the insufficient amount. Is subtracted. In other words, when displaying one image, when a plurality of frames are sequentially scanned in the vertical direction of the display screen, the reflection is performed on both adjacent pixels sandwiching the target pixel in the vertical direction.

  More specifically, the reflection unit 16B adds 1/2 of the excess or deficiency calculated by the calculation unit 15 to the pixel corresponding to the target pixel in the immediately preceding correction frame stored in the n-1 frame memory 61. reflect. In addition, the reflection unit 16B adds the excess or deficiency calculated by the calculation unit 15 to the pixel corresponding to the target pixel in the immediately subsequent frame stored in the n + 1 frame memory 31 of the next frame changing unit 30. Reflect. That is, in the next frame changing unit 30, in accordance with an instruction from the reflecting unit 16B, processing for reflecting the excess or ½ of the excess is performed on the immediately following frame.

  As described above, the frame immediately before correction is stored in the n−1 frame memory 61, and is output to the data line driving circuit 50 after the reflection processing by the reflection unit 16 </ b> B is performed. Thereby, when one image is displayed, the reflection is performed on both adjacent pixels sandwiching the target pixel in the vertical direction.

  The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  Note that the determination unit 14, the calculation unit 15, and the reflection unit 16 </ b> B described above may be configured by hardware logic, or may be constructed in software by the CPU 11 executing a predetermined program.

  The display device 1 according to the present invention converts the gradation value of each pixel of the one frame based on the gradation value change between one frame of the pixel row to be displayed and the immediately preceding frame immediately before the one frame. In the display device 1 that performs an overdrive process for adding an additional value, the gradation value obtained by adding the additional value for the pixel of interest exceeds the first threshold value, or from the first threshold value. Determining means 14 for determining whether or not the low second threshold has been reached, and exceeding the first threshold when the determining means 14 determines that the first threshold has been exceeded or has not reached the second threshold Minutes, or a calculation means 15 for calculating the shortage up to the second threshold, and reflection means 16, 16A, 16B, 19 for reflecting the excess or deficiency on the neighboring pixels of the target pixel. It is characterized by that.

  In the present invention, the determination means has a second gradation value obtained by adding the additional value to the pixel of interest that exceeds the first threshold or is lower than the first threshold. It is determined whether the threshold has been reached. In addition, when it is determined by the determination unit that the first threshold value is exceeded or the second threshold value is not reached, the calculation unit determines whether the excess value exceeds the first threshold value or the second threshold value. Calculate the shortage. The reflection unit reflects the excess or deficiency calculated by the calculation unit on the adjacent pixel of the target pixel.

  The display device 1 according to the present invention converts the gradation value of each pixel of the one frame based on the gradation value change between one frame of the pixel row to be displayed and the immediately preceding frame immediately before the one frame. In the display device 1 that performs an overdrive process for adding an additional value, an arrival value calculation means 17 that calculates a reachable gradation value that can actually be reached based on the processed gradation value obtained by the overdrive process for the target pixel. And subtracting means 18 for subtracting the reached gradation value from the gradation value of the target pixel, and reflecting means 16, 16A, 16B for reflecting the subtraction result of the subtracting means to adjacent pixels of the target pixel. , 19.

  In the present invention, the reached value calculation means calculates a reachable gradation value that can actually be reached based on the processed gradation value obtained by the overdrive processing for the target pixel. The subtracting unit subtracts the reached gradation value from the gradation value of the target pixel. The reflection unit reflects the subtraction result obtained by the subtraction unit on the adjacent pixel of the target pixel.

  The display device 1 according to the present invention is characterized in that the reflection means 16, 16A, 16B, and 19 are configured to perform the reflection on the pixel to be overdriven after the pixel of interest. To do.

  In the present invention, the reflection means reflects the excess or deficiency or the subtraction result on the pixel to be overdriven after the pixel of interest.

  In the display device 1 according to the present invention, the reflection means 16, 16A, 16B, and 19 perform the reflection on adjacent pixels in the moving direction of the moving object when the image related to the one frame is a moving image. It is comprised by these.

  In the present invention, the reflection means reflects the excess or deficiency, or the subtraction result, and when the image related to the one frame is a moving image, the adjacent pixel in the moving direction of the moving object The above reflection is performed.

  The display device 1 according to the present invention is characterized in that the reflection means 16, 16A, 16B, and 19 are configured to perform the reflection on both pixels sandwiching the pixel of interest in the one frame. And

  In the present invention, the reflecting means performs the reflection on both pixels sandwiching the pixel of interest in the one frame when reflecting the excess or deficiency or the subtraction result.

  The display device 1 according to the present invention reflects the reflection on the pixel corresponding to the pixel of interest in the immediately preceding frame and the pixel corresponding to the pixel of interest in the immediately following frame to be processed immediately after the one frame. It is comprised so that it may perform.

  In the present invention, the reflection means reflects the excess or deficiency, or the subtraction result, and a pixel corresponding to the pixel of interest in the immediately preceding frame and immediately after the one frame. The reflection is performed on the pixel corresponding to the target pixel in the immediately subsequent frame to be processed.

  In the display device 1 according to the present invention, the subtraction result of the subtraction unit is corrected according to the operating temperature, and the reflection units 16, 16A, 16B, and 19 use the corrected subtraction result of the subtraction unit for the reflection. It is comprised so that it may perform.

  In the present invention, the subtraction result of the subtraction means is corrected according to the operating temperature, and the reflection means performs the reflection using the corrected subtraction result of the subtraction means.

1 Display device 11 CPU
14 determining unit 15 calculating unit 16, 16A, 16B, 19 reflecting unit 17 reaching value calculating unit 18 subtracting unit

Claims (6)

Overdrive processing for adding an additional value to the gradation value of each pixel of the one frame based on the gradation value change between one frame of the pixel row to be displayed and the immediately preceding frame immediately before the one frame. In the display device to perform,
An arrival value calculation means for calculating a reached gradation value that can actually be reached based on the processed gradation value obtained by the overdrive processing for the target pixel;
Subtracting means for subtracting the reached gradation value from the gradation value of the target pixel;
Reflecting means for reflecting the subtraction result of the subtracting means to a pixel adjacent to the pixel of interest. The display device according to claim 1, wherein the reflection unit is configured to perform the reflection on a pixel to be overdriven after the pixel of interest. Said reflecting means, when an image according to the one frame is a moving, according to claim 1, characterized in that it is configured to perform the reflection with respect to the direction of movement of the adjacent pixels of the moving Display device. The display device according to claim 1, wherein the reflection unit is configured to perform the reflection on both pixels sandwiching the target pixel in the one frame. The reflection is performed on the pixel corresponding to the target pixel in the immediately preceding frame and the pixel corresponding to the target pixel in the immediately following frame to be processed immediately after the one frame. The display device according to claim 1 . The subtraction result of the subtracting means is corrected according to the operating temperature,
The display device according to claim 1 , wherein the reflection unit is configured to perform the reflection using the corrected subtraction result of the subtraction unit.

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