JP2010262240A - Display device and display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device and a display method, wherein the image quality of moving image displayed by a liquid crystal display panel can be improved by estimating accurate temperature of each pixel of the liquid crystal display panel. <P>SOLUTION: A first correction table R1 to a third correction table R3 of three kinds are stored in a ROM 13. An operation part 21 estimates accurate temperature of each pixel of the liquid crystal display panel 12 based on respective detected results of a plurality of temperature sensors 23, 23, ... and illumination status of respective pixels of the liquid crystal panel 12 by a backlight 32. Moreover, based on the estimated result, the operation part selects any one of the first correction table R1 to the third correction table R3. An image processing part 11 generates control data based on the image data, and corrects the generated control data by using an optimum correction table R selected by the operation part 21. The liquid crystal display panel 12 displays moving image the image quality of which is improved according to the control data corrected appropriately by the image processing part 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a display device and a display method for displaying a moving image.

A liquid crystal display panel is widely used as a non-light emitting display panel illuminated by a backlight. The liquid crystal display panel is provided in a liquid crystal display device such as a liquid crystal television device.
In the liquid crystal display panel, an image is displayed by applying a voltage to the liquid crystal. Control data for controlling the voltage to be applied to the liquid crystal is generated based on the image data.

  In order to improve the image quality of moving images displayed on the liquid crystal display panel, conventionally, by referring to a conversion table for converting image data (hereinafter referred to as input image data) input to the liquid crystal display device into control data. Techniques for generating control data have been proposed (see Patent Documents 1 and 2). In this case, each control value included in the control data is determined based on each pixel value included in the input image data and each pixel value included in the image data input one frame before the input image data. .

  The response speed of the liquid crystal is very temperature dependent. However, the temperature distribution of the liquid crystal display panel is not uniform. Therefore, in order to greatly improve the image quality, it is necessary to appropriately obtain the representative temperature of the liquid crystal display panel and switch the conversion table to be referred to when generating the control data according to the obtained representative temperature level. .

  In the liquid crystal display devices disclosed in Patent Documents 1 and 2, a temperature sensor is disposed corresponding to each of rectangular areas obtained by virtually dividing the liquid crystal display panel into four. Such a liquid crystal display device has an average value, a maximum value, or a minimum value of detection results of four temperature sensors, or a detection result of a temperature sensor corresponding to a rectangular region where the motion of the displayed moving image is the largest. Is used as the representative temperature of the liquid crystal display panel.

Conventionally, a backlight having a plurality of light sources (for example, LEDs) arranged in a matrix is used. The plurality of light sources are arranged corresponding to a plurality of display areas obtained by virtually dividing the display panel.
For such a backlight, local dimming control for turning on / off each light source and adjusting the luminance of the light source that is lit is executed based on the image data. As a result, each display area is illuminated with a luminance suitable for the color and brightness of the moving image displayed in each display area.

JP 2004-163870 A JP 2007-226262 A

In order to switch the conversion table appropriately, it is desirable to obtain a detailed temperature distribution of the liquid crystal display panel.
For this purpose, for example, the detection result of each of the plurality of temperature sensors is regarded as the temperature of a pixel corresponding to the position of each temperature sensor in the liquid crystal display panel (hereinafter referred to as a sensor-corresponding pixel). It is conceivable to estimate the temperature of each pixel located between the pixel and another sensor-corresponding pixel by linear interpolation using the temperature of one sensor-corresponding pixel and the temperature of another sensor-corresponding pixel.

However, in the case of a backlight in which local dimming control is performed, the temperature of the display area illuminated by a light source that is lit (or a light source with high luminance) is a light source that is turned off (or a light source with low luminance). ) Higher than the temperature of the display area illuminated.
Therefore, there is a possibility that the estimated temperature and the actual temperature of the liquid crystal display panel differ greatly only by simple linear interpolation.

  The present invention has been made in view of such circumstances, and the main object of the present invention is based on the detection results of each of the plurality of temperature sensors and the illumination status of each pixel of the display panel by the backlight. By estimating the temperature of each pixel, generating control data based on the estimation result and image data, and displaying the moving image according to the generated control data, the image quality of the displayed moving image can be improved. An object of the present invention is to provide a display device and a display method that can be used.

  A display device according to the present invention includes a display panel that displays a moving image according to control data generated based on image data input in time series, a backlight that individually illuminates each part of the display panel, and an arrangement In a display device comprising a plurality of temperature sensors that respectively detect the temperature of a position and a plurality of types of generating means for generating the control data, the detection results of each of the temperature sensors and the display panel by the backlight Temperature estimating means for estimating the temperature of each pixel of the display panel based on the illumination state of each pixel, and selecting means for selecting any one of the generating means based on the estimation result of the temperature estimating means; The control data is generated using the generation means selected by the selection means.

  In the display device according to the present invention, the temperature estimation unit is configured to estimate a temperature of a pixel corresponding to the arrangement position of the temperature sensor based on a detection result of each temperature sensor, and the backlight has a first luminance. The temperature of each of the pixels located at the boundary between the first region where the pixels to be illuminated are adjacent to each other and the second region where the pixels where the backlight illuminates at a second luminance different from the first luminance is adjacent, The estimation is based on the temperature of the first pixel that is included in the first region and whose temperature has already been estimated, and the temperature of the second pixel that is included in the second region and whose temperature has already been estimated. Means for estimating a temperature of a pixel excluding a pixel located at the boundary portion included in the first area based on a temperature of the first pixel; and a position located at the boundary portion included in the second area. The pixel temperature excluding the And having a means for estimating, based on the temperature of the second pixel.

  The display device according to the present invention further includes a fluctuation detection unit that detects a fluctuation of a moving image displayed on the display panel, and the selection unit uses the estimation result of the temperature estimation unit and the detection result of the fluctuation detection unit. Based on the above, any one of the generating means is selected.

  A display method according to the present invention includes a display panel that displays a moving image according to control data generated based on image data input in time series, a backlight that individually illuminates each part of the display panel, and an arrangement In a display method for displaying a moving image on a display device comprising a plurality of temperature sensors for detecting the temperature of each position and a plurality of types of generating means for generating the control data, the detection results of each of the temperature sensors And estimating the temperature of each pixel of the display panel based on the illumination status of each pixel of the display panel by the backlight, and selecting one of the generating means based on the estimated temperature, and selecting The control data is generated using the generating means.

In the present invention, for example, the display method of the present invention is executed using the display device of the present invention.
The display device of the present invention includes a display panel, a backlight, a plurality of temperature sensors, and a plurality of types of generating means. In addition, the display device of the present invention further includes a temperature estimation unit and a selection unit.

The backlight illuminates each part of the display panel individually. Hereinafter, each part of the display panel illuminated by the backlight is referred to as each display area of the display panel.
Such a backlight can be regarded as a heat source having a non-uniform temperature. This is because the portion of the backlight that illuminates the display area with high luminance (or low luminance) can be regarded as a high-temperature (or low-temperature) heat source.
Each temperature sensor detects the temperature of its own arrangement position. If the temperature of each pixel of the display panel is estimated based only on the detection result of the temperature sensor, a detailed temperature distribution of the display panel can be obtained. However, since the presence of a backlight which is a heat source with non-uniform temperatures is not taken into consideration, the estimated temperature of each pixel may be significantly different from the actual temperature.

  Therefore, the temperature estimation unit is configured to detect the temperature of each pixel of the display panel based on the detection result of each of the plurality of temperature sensors and the illumination state of each pixel of the display panel using the backlight (for example, the brightness level of each pixel). Is estimated. In this case, an accurate and detailed temperature distribution of the display panel can be obtained.

Here, each generation means is for generating control data based on image data input in time series. Based on the same image data, control data generated using each of a plurality of types of generating means are different from each other.
The selection means selects any one of a plurality of types of generation means based on the estimation result of the temperature estimation means. Since the accurate and detailed temperature distribution of the display panel can be taken into account when selecting the generation means, the selection means can select an optimal generation means according to the temperature dependence of the response speed of the display panel. .
Control data is generated using the generation means selected as described above. The display panel displays a moving image according to the generated control data.

In the present invention, the temperature estimating means first estimates the temperature of the pixel corresponding to the arrangement position of each temperature sensor based on the detection result of each temperature sensor. Therefore, the temperature of each of at least the same number of pixels as the number of temperature sensors is estimated.
Hereinafter, the temperature estimated by the temperature estimation means is referred to as an estimated temperature.
After estimating the temperature of the pixel corresponding to the arrangement position of each temperature sensor, the temperature estimation means estimates the temperature of pixels other than the pixel corresponding to the arrangement position of each temperature sensor.

For this purpose, the temperature estimation means uses the temperature of each pixel located at the boundary between the first area and the second area as the estimated temperature of the first pixel included in the first area and the second area included in the second area. Estimate based on the estimated temperature of the pixel.
Further, the temperature estimation means estimates the temperature of the pixels excluding the pixels located at the boundary part included in the first region (that is, the pixel located at the center of the first region) based on the estimated temperature of the first pixel. . Further, the temperature estimation means estimates the temperature of the pixels excluding the pixels located at the boundary part included in the second region (that is, the pixel located at the center of the second region) based on the estimated temperature of the second pixel. .

The first region is a region where pixels that the backlight illuminates at the first luminance are adjacent to each other. For this reason, it can be considered that the temperature of each pixel located in the central portion of the first region is substantially equal.
On the other hand, the temperature of each pixel located at the boundary between the first region and the second region is considered to be different from the temperature of each pixel located at the center of the first region. This is because the boundary with the second region is strongly influenced by the second region.

  Similarly, the second region is a region where pixels that the backlight illuminates with the second luminance are adjacent to each other. For this reason, it can be considered that the temperature of each pixel located in the center of the second region is substantially equal. In addition, it is considered that the temperature of each pixel located at the boundary between the second region and the first region is different from the temperature of each pixel located at the center of the second region. This is because the boundary with the first region is strongly influenced by the first region.

  Therefore, an accurate temperature can be estimated by estimating the temperature of each pixel located at the boundary portion based on the estimated temperature of the first pixel and the estimated temperature of the second pixel. On the other hand, the temperature of each pixel located in the central portion of the first region (or the second region) is that of the first pixel (or the second pixel) regardless of the estimated temperature of the second pixel (or the first pixel). By estimating based on the estimated temperature, an accurate temperature can be estimated.

In the present invention, the fluctuation detecting means detects the fluctuation of the moving image displayed on the display panel.
The user of the display device tends to pay attention to a portion where the variation of the moving image displayed on the display panel is large. Therefore, it is desirable to select the generation means based on the temperature of the portion that is easily noticed by the user of the display panel.
Therefore, the selection means selects any one of the generation means based on the estimation result of the temperature estimation means and the detection result of the fluctuation detection means.
As a result, it is possible to sufficiently improve the image quality of the moving image displayed on the portion of the display panel that is easily noticed by the user.

In the case of the display device of the present invention and the display method of the present invention, the backlight is regarded as a heat source with non-uniform temperatures, and when estimating the temperature of each pixel, the arrangement of the high-temperature part and the low-temperature part of the backlight, respectively. The position can be taken into account.
Therefore, an accurate and detailed temperature distribution of the display panel can be obtained based on the detection result of each of the plurality of temperature sensors and the illumination state of each pixel by the backlight.

Furthermore, based on the accurate and detailed temperature distribution of the display panel, it is possible to appropriately switch the table or function used when generating the control data. Appropriate control data according to the temperature distribution of the display panel can be generated.
As a result, the image quality of the moving image displayed on the display panel can be improved.

It is a block diagram which shows the principal part structure of the display apparatus which concerns on Embodiment 1 of this invention. It is a characteristic view which shows the temperature distribution of the liquid crystal display panel with which the display apparatus which concerns on Embodiment 1 of this invention is provided. It is a schematic diagram which shows an example of the temperature LUT memorize | stored in RAM with which the display apparatus which concerns on Embodiment 1 of this invention is provided. It is a flowchart which shows the procedure of the image calculation process performed with the display apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the procedure of the image calculation process performed with the display apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the subroutine of the temperature distribution estimation process procedure performed with the display apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the subroutine of the temperature distribution estimation process procedure performed with the display apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the subroutine of the correction table selection process procedure performed with the display apparatus which concerns on Embodiment 1 of this invention. It is a characteristic view which shows the temperature distribution of the liquid crystal display panel with which the display apparatus which concerns on Embodiment 2 of this invention is provided. It is a block diagram which shows the principal part structure of the display apparatus which concerns on Embodiment 3 of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

Embodiment 1.
FIG. 1 is a block diagram showing a main configuration of a display device 1 according to Embodiment 1 of the present invention.
The display device 1 includes an image receiving unit 10, an image processing unit 11, a liquid crystal display panel 12, a ROM 13, a frame memory 14, a calculation unit 21, a RAM 22, temperature sensors 23, 23,. Is provided.
The display device 1 is connected to an image transmission device (not shown) such as a tuner, a DVD player, a server, or a personal computer main body.

  The image receiving unit 10 receives image data transmitted from the image transmitting device to the display device 1 in time series, and the received image data for each frame, the image processing unit 11, the frame memory 14, and the backlight control. Output to each of the units 31. Note that the image receiving unit 10 may have a tuner function and output image data obtained by converting the received television broadcast signal to predetermined units. Or the structure which outputs the image data read from the external memory | storage device which is not shown in figure with which the display apparatus 1 is equipped, a secondary storage device, etc. may be sufficient.

The frame memory 14 is a first-in first-out type image memory capable of storing image data for one frame input to itself. The image data stored in the frame memory 14 is read from the frame memory 14 and output to the image processing unit 11 when the image data after one frame of the image data is input to the frame memory 14. .
In other words, the image processing unit 11 receives image data output from the image receiving unit 10 (hereinafter referred to as current image data) and image data output from the frame memory 14 (hereinafter referred to as past image data). The The past image data is image data one frame before the current image data. Hereinafter, when the current image data and the past image data are not distinguished, they are simply referred to as image data.

  The liquid crystal display panel 12 includes a large number of liquid crystal units (“LC” in the figure) 121, 121,... Arranged in a matrix between two light-transmitting substrates (not shown). Each liquid crystal unit 121 corresponds to a pixel of the liquid crystal display panel 12. Each liquid crystal unit 121 corresponds to each pixel of image data.

  Control data corresponding to the image data is input to the liquid crystal display panel 12 for each frame in time series. The control data includes a control value corresponding to each pixel. Here, the control value corresponding to each pixel is for the liquid crystal display panel 12 to control the voltage to be applied to each liquid crystal unit 121. The liquid crystal display panel 12 applies a voltage to each liquid crystal unit 121 according to the input control data. If the voltage value of the voltage applied to each liquid crystal unit 121 is appropriate, a high-quality moving image is displayed on the liquid crystal display panel 12.

The image processing unit 11 should generate temporary control data based on the input current image data, and then output the generated temporary control data to the liquid crystal display panel 12 by correcting as will be described later. Generate control data. Next, the image processing unit 11 outputs the generated control data to the liquid crystal display panel 12.
The ROM 13 stores three types of first correction table R1, second correction table R2, and third correction table R3. Hereinafter, when these are not distinguished, they are simply referred to as a correction table R. The correction table R is for compensating the optical response characteristics of the liquid crystal display panel 12, and the degree of compensation is different from each other.

  Each correction table R is used to obtain a correction value for correcting temporary control data based on a combination of each pixel value of the current image data and each pixel value of the past image data. Even if the combination of the pixel value of the current image data and the pixel value of the past image data is the same, the case where the first correction table R1 is referenced, the case where the second correction table R2 is referenced, and the third The correction value obtained may differ from the case of referring to the correction table R3. Such first correction table R1, second correction table R2, and third correction table R3 function as a plurality of types of generating means of the present invention.

The selection of the correction table R is executed by the calculation unit 21 as will be described later. The calculation unit 21 outputs a selection signal indicating the type of the correction table R to be selected for each pixel included in the current image data to the image processing unit 11.
When correcting the temporary control data, the image processing unit 11 refers to the correction table R corresponding to the selection signal input to itself, and inputs each pixel value of the current image data and each pixel value of the past image data. Based on the combination, the correction value for correcting the temporary control data is obtained. Then, the image processing unit 11 corrects each control value of the temporary control data using the obtained correction value.

Incidentally, the selection signal input to the image processing unit 11 may be different for each pixel. That is, the correction table R may be switched for each pixel. Therefore, each control value included in the temporary control data may be corrected with reference to a different correction table R, or may be corrected with reference to the same correction table R. As a result, each control value included in the provisional control data can be finely corrected for each pixel.
Note that the number of types of the correction table R is not limited to three, and may be two or four or more.

In addition, the configuration is not limited to the configuration in which all three types of correction tables R are stored in one ROM 13, but the first correction tables R1 and the second correction tables R1 and R2 have a one-to-one correspondence with the three ROMs 13, 13,. The correction table R2 and the third correction table R3 may be stored.
Further, the generation means is not limited to the correction table R, and may be a function for correcting the control value. The generating means is a table or function for directly obtaining the control value of the control data (that is, without generating temporary control data) using the pixel values of the current image data and the past image data. May be.

  Furthermore, the display device 1 is not limited to a configuration in which a selection signal is input / output for each pixel. The display device 1 may have a configuration in which a selection signal is input / output for each rectangular block including a plurality of pixels, for example. In this case, since the correction table R is switched at most for each block, flickering of the moving image displayed on the liquid crystal display panel 12 is suppressed. Alternatively, the display device 1 may be configured such that a selection signal is input / output for each frame. In this case, since the correction table R is switched every frame at most, flickering of the moving image displayed on the liquid crystal display panel 12 is further suppressed.

  The display device 1 is not limited to the configuration including the image processing unit 11 and the ROM 13. For example, the display device 1 includes three types of image processing units that include a first correction table R1, a second correction table R2, and a third correction table R3 in a one-to-one correspondence, and the calculation unit 21 selects an image to be selected. The selection signal indicating the type of the processing unit may be output to each of the image receiving unit 10 and the frame memory 14.

  In this case, each of the image receiving unit 10 and the frame memory 14 outputs the current image data and the past image data to the image processing unit corresponding to the selection signal input thereto. The image processing unit to which the current image data and past image data are input generates control data based on the input current image data and past image data. Such an image processing unit functions as a generation unit.

Incidentally, in general, the liquid crystal display panel 12 has a low response speed. For this reason, there is a problem that afterimages are easily generated and it is difficult to accurately display halftones. The control data correction process executed by the image processing unit 11 is for solving this problem.
However, the slow response speed of the liquid crystal display panel 12 largely depends on the temperature of the liquid crystal display panel 12.
For this reason, if the temperature distribution of the liquid crystal display panel 12 is uniform, the display device 1 detects the temperature of a part of the liquid crystal display panel 12 and performs control data correction processing according to the detected temperature. The correction table R may be selected and each control value of the temporary control data may be corrected with reference to the selected correction table R.

However, the temperature of the liquid crystal display panel 12 is not uniform. Therefore, in order to appropriately correct each control value, the correction table R is selected using the detailed temperature distribution of the liquid crystal display panel 12, and each control of the temporary control data is referred to with reference to the selected correction table R. The value needs to be corrected.
In order to obtain the most accurate and detailed temperature distribution of the liquid crystal display panel 12, a temperature sensor may be arranged for each pixel of the liquid crystal display panel 12 to detect the temperature of each pixel. Such a configuration is practical. is not.

In the present embodiment, N temperature sensors (“TS” in the figure) 23, 23,... Are arranged in a matrix so as to face the back surface of the liquid crystal display panel 12. More specifically, the N temperature sensors 23, 23,... Are arranged corresponding to N rectangular display areas obtained by virtually dividing the liquid crystal display panel 12.
However, “N” is a natural number equal to or greater than “2”, and the number N is significantly smaller than the number of liquid crystal units 121, 121,... Of the liquid crystal display panel 12.

Each temperature sensor 23 detects the temperature of its arrangement position at every predetermined sampling time, and outputs the detected temperature (hereinafter referred to as a temperature detection result) to the calculation unit 21.
In the present embodiment, it is assumed that the temperature detection result of each temperature sensor 23 is equal to the temperature of the pixel located at the center of the rectangular display area corresponding to the arrangement position of the temperature sensor 23.

Each rectangular display area of the liquid crystal display panel 12 includes the same number of liquid crystal units 121, 121,... (For example, 5 vertical × 5 horizontal liquid crystal units 121, 121,...).
Note that the number of liquid crystal units 121, 121,... Included in each rectangular display area may be different. In this case, for example, the rectangular display area at the center of the liquid crystal display panel 12 includes 3 × 3 liquid crystal parts 121, 121,..., And the rectangular display area at the peripheral edge of the liquid crystal display panel 12 has 5 pieces. × 5 liquid crystal units 121, 121,... Are included.

By the way, the main cause of the non-uniform temperature distribution of the liquid crystal display panel 12 is the presence of the backlight 32.
The backlight 32 individually illuminates N rectangular display areas. Therefore, the backlight 32 faces the back surface of the liquid crystal display panel 12, and N light emitting diodes (LEDs) 321, 321,... Are arranged in a matrix. More specifically, the N LEDs 321, 321,... Are arranged corresponding to the N rectangular display areas. Each LED 321 illuminates a corresponding rectangular display area.

  In addition, the backlight 32 is not limited to the structure by which N LED321,321, ... is arrange | positioned at matrix form. For example, the backlight 32 may have a configuration in which a plurality of fluorescent lamps are arranged in parallel to each other.

The rectangular display area corresponding to each temperature sensor 23 and the rectangular display area illuminated by each LED 321 may be different in arrangement position, shape, number, or the like.
However, it is desirable that the number of temperature sensors 23, 23,... Be equal to or greater than the number of LEDs 321, 321,. In this case, if at least one temperature sensor 23 is arranged corresponding to the rectangular display area illuminated by each LED 321, the liquid crystal display panel 12 is processed in the same procedure as the image calculation processing shown in FIGS. 4 and 5 described later. The temperature of each pixel can be estimated.

  In the present embodiment, in order to simplify the description, a case where a rectangular display area corresponding to each temperature sensor 23 and a rectangular display area illuminated by each LED 321 coincide is illustrated.

  A luminance signal indicating the luminance of each LED 321 is input to the backlight 32 from a backlight control unit 31 described later. The backlight 32 lights each LED 321 with the luminance according to the input luminance signal. However, when the input luminance signal indicates zero luminance, the backlight 32 turns off each LED 321.

The backlight control unit 31 performs local dimming control on the backlight 32. For this purpose, the backlight control unit 31 calculates the luminance of each of the LEDs 321, 321,... Based on the current image data input to the backlight control unit 31, and outputs the luminance signal according to the calculation result to the calculation unit 21 and the backlight. 32 to each. More specifically, the backlight control unit 31 determines the brightness and color of an image displayed in each rectangular display area when the current image data is input to the liquid crystal display panel 12 based on the pixel value of the current image data. And the luminance of the LED 321 that proves each rectangular display area is calculated according to the calculation result, and a luminance signal corresponding to the calculation result is output to the calculation unit 21 and the backlight 32, respectively.
Therefore, the luminance of each LED 321 changes for each frame at the maximum.

  As a result, the backlight 32 illuminates each rectangular display area with a luminance suitable for the color and brightness of the moving image displayed in each rectangular display area. Specifically, a rectangular display area where a bright video or a video with a conspicuous color is displayed (that is, a rectangular display area that is easy for the user to pay attention) is illuminated with high brightness, and a dark video or a video with an inconspicuous color is displayed. The displayed rectangular display area (that is, the rectangular display area that is difficult for the user to pay attention) is illuminated with low luminance.

The high-luminance (or low-luminance) LED 321 acts as a high-temperature (or low-temperature) heat source. As a result, the temperature of the rectangular display area illuminated by the LED 321 that is a high-temperature (or low-temperature) heat source tends to be high (or low). Therefore, the temperature distribution of the liquid crystal display panel 12 is non-uniform and changes over time.
Here, let the main scanning direction and the sub-scanning direction of the liquid crystal display panel 12 (or image data) be the x coordinate direction and the y coordinate direction. At this time, the coordinates (x, y) indicate the position of each pixel. In other words, each pixel can be specified by the coordinates (x, y). In the following, the maximum values of the coordinate values x and y in the x direction and y direction are the maximum coordinate values x _max and y _max , respectively, and the values of the coordinate values x and y are 1 ≦ x, y ≦ x _max , y _{max, respectively.} Is a natural number of.

FIG. 2 is a characteristic diagram showing the temperature distribution of the liquid crystal display panel 12.
More specifically, the temperature distribution shown in FIG. 2 is a temperature distribution in the x-axis direction at the position of the y coordinate value y ₁ . In the figure, the horizontal axis indicates the x coordinate value of each pixel of the liquid crystal display panel 12. The vertical axis indicates the temperature of each pixel and the luminance of the backlight 32 that illuminates each pixel. Temperature is represented by a line graph, and brightness is represented by a bar graph. The luminances L ₁ and L ₂ are 0 <L ₁ <L ₂ .

A graph G1 indicated by a broken line represents an actual temperature distribution.
A graph G2 indicated by a thin solid line represents a temperature distribution estimated by linearly complementing the temperature detection results of the N temperature sensors 23, 23,.
A graph G3 indicated by a thick solid line shows a temperature distribution estimated based on the temperature detection result of each of the N temperature sensors 23, 23,... And the illumination state of each pixel of the liquid crystal display panel 12 by the backlight 32. It represents.

In the figure, the pixel of coordinates (x ₁ , y ₁ ), (x ₂ , y ₁ ),... Is the central pixel of the rectangular display area to which the temperature sensors 23, 23,.
The temperature of the pixel at the coordinates (x ₁ , y ₁ ), (x ₂ , y ₁ ),... Is the temperature T ₁₁ , T ₂₁ , ..., and the coordinates (x ₁ , y ₁ ), (x ₂ , y ₁ ) The temperature sensors 23, 23,... Corresponding to the rectangular display area including the pixels... Detect the temperatures T ₁₁ , T ₂₁ ,.

For example, when it is desired to estimate the temperature of each pixel located between the coordinates (x ₁ , y ₁ ) and the coordinates (x ₂ , y ₁ ), the coordinates (x ₁ , T ₁₁ ) and the coordinates (x ₂ , T _21). The simplest method is to calculate the estimated temperature T by substituting the x coordinate value of the pixel whose temperature is to be estimated into the following equation (1), which is the obtained linear function. .
_{T = {(T 21 -T 11} ) / (x 2 -x 1)} x + (T 11 × x 2 -T 21 × x 1) / (x 2 -x 1) ... (1)

Such a method is applied between coordinates (x ₂ , y ₁ ) and coordinates (x ₃ , y ₁ ), between coordinates (x ₃ , y ₁ ) and coordinates (x ₄ , y ₁ ), and so on. By repeatedly executing, a temperature distribution in the x-axis direction at the position of the y coordinate value y ₁ is obtained. A graph G2 shown in FIG. 2 is obtained by this method.

By the way, LEDs 321, 321,... That illuminate rectangular display areas each including pixels of coordinates (x ₁ , y ₁ ), (x ₄ , y ₁ ), (x ₆ , y ₁ ), (x ₈ , y ₁ ). Respectively have a luminance of 0 (ie, they are turned off). Further, the LEDs 321, 321,... That illuminate the rectangular display areas including the pixels of the coordinates (x ₂ , y ₁ ), (x ₃ , y ₁ ), (x ₅ , y ₁ ) respectively have the luminance L ₂ . . Further, the LED 32 that illuminates the rectangular display area including the pixel at the coordinates (x ₇ , y ₁ ) has the luminance L ₁ .
Here, the comparison between the graph G1 indicating the actual temperature distribution and the graphs G2 and G3 indicating the estimated temperature distribution will be specifically described.

The rectangular display area including the coordinates (x ₃ , y ₁ ) is illuminated by the backlight 32 with the luminance L ₂ , and the rectangular display area including the coordinates (x ₄ , y ₁ ) is the backlight 32 having the luminance 0. Illuminated by lighting.
As the graph G1 shows, the actual temperature distribution in the center of the rectangular display area including the coordinates (x ₃ , y ₁ ) is substantially uniform at high temperatures. Further, the actual temperature distribution in the central portion of the rectangular display area including the coordinates (x ₄ , y ₁ ) is substantially uniform at a low temperature. The level of the temperature in each rectangular display area corresponds to the level of the brightness of the backlight 32 that illuminates each rectangular display area.

On the other hand, the actual temperature distribution at the boundary between the rectangular display area including the coordinates (x ₃ , y ₁ ) and the rectangular display area including the coordinates (x ₄ , y ₁ ) is gradual from the higher luminance to the lower luminance. The temperature has dropped.
Therefore, comparing the graph G1 and the graph G2, it can be seen that the temperature distribution obtained by linear interpolation is significantly different from the actual temperature distribution.

Therefore, the calculation unit 21 calculates the temperature of each pixel of the liquid crystal display panel 12 based on the temperature detection result input from each of the temperature sensors 23, 23,... And the luminance signal input from the backlight control unit 31. presume.
The luminance signal input from the backlight control unit 31 indicates the luminance of each LED 321. Each LED 321 corresponds to each rectangular display area of the liquid crystal display panel 12. The calculation unit 21 in the present embodiment uses the luminance of the LED 321 corresponding to the rectangular display region including each pixel as the illumination state of each pixel of the liquid crystal display panel 12 by the backlight 32.
Such a calculation part 21 functions as a temperature estimation means in the present invention.

  The computing unit 21 generates a temperature LUT (Look Up Table) by storing the estimated temperature of each pixel in the RAM 22 in association with the coordinates (x, y) of each pixel.

FIG. 3 is a schematic diagram illustrating an example of the temperature LUT stored in the RAM 22.
Like the pixels at coordinates (3, 3), (3, 8),..., The pixels indicated by hatching are pixels corresponding to the temperature sensors 23, 23,.
Referring to the temperature LUT, for example, it can be easily understood that the temperature of the pixel at the coordinates (1, 1) is 10 ° C. and the temperature of the pixel at the coordinates (2, 3) is 20 ° C.
The calculating unit 21 refers to the generated temperature LUT, determines the type of the correction table R to be selected, and outputs a selection signal indicating the determination result to the image processing unit 11.
Such a calculation part 21 functions as a selection means in the present invention.

Note that the calculation unit 21 may be configured to use not the luminance of the LED 321 but the on / off state of the LED 321 as the illumination state of each pixel. Or the structure using the change of the brightness | luminance of LED321 may be sufficient as the calculating part 21. FIG.
In addition, the calculation unit 21 may have a function of not only a function of estimating the temperature and a function of selecting the correction table R but also a function as a control center of the display device 1.

4 and 5 are flowcharts showing a procedure of image calculation processing executed by the calculation unit 21. FIG.
As shown in FIG. 4, the calculating unit 21 first initializes the temperature LUT (S11). In this case, the calculation unit 21 writes a meaningless numerical value to each pixel of the temperature LUT as shown in FIG.
Next, the calculation unit 21 determines whether or not a luminance signal is input from the backlight control unit 31 (S12). If the luminance signal is not input yet (NO in S12), the processing of S12 is repeatedly executed.

When a luminance signal is input from the backlight control unit 31 (YES in S12), the calculation unit 21 acquires temperature detection results from the temperature sensors 23, 23,... (S13), and the acquired temperature detection results are Write to the temperature LUT (S14). More specifically, the calculation unit 21 writes the temperature detection result of each temperature sensor 23 in the temperature LUT as the estimated temperature of the pixel located at the center of the rectangular display area corresponding to the position where the temperature sensor 23 is arranged.
Hereinafter, a pixel in which the estimated temperature is written in the temperature LUT is referred to as an estimated pixel. A pixel in which the estimated temperature is not written in the temperature LUT is referred to as an unestimated pixel.
After the process of S14 ends, the calculation unit 21 moves the process to S15.

The computing unit 21 resets the variables i and j to “1” (S15), and moves the process to S16.
Next, the computing unit 21 selects the j-th line of the temperature LUT (S16), scans the selected line in the x-axis direction, and determines whether both the estimated pixel and the unestimated pixel exist. (S17). When both the estimated pixel and the non-estimated pixel exist (YES in S17), the calculation unit 21 executes a subroutine (see FIGS. 6 and 7) that performs a temperature distribution estimation process for estimating the temperature distribution of the jth line. Call and execute (S18).

6 and 7 are flowcharts showing a subroutine of the temperature distribution estimation processing procedure executed by the calculation unit 21. FIG.
As shown in FIG. 6, the computing unit 21 resets each of the variables m and n to “1” (S41).
Next, the computing unit 21 determines whether or not the m-th pixel of the j-th line is an estimated pixel (S42). If the pixel is an unestimated pixel (NO in S42), the variable m is set to “1”. "Increment (S43) and return to S42.

  When the m-th pixel is an estimated pixel (YES in S42), the calculation unit 21 identifies the m-th pixel as the n-th pixel (S44), and determines the luminance of the identified n-th pixel in S12. It calculates | requires based on the input luminance signal (S45). Further, the calculation unit 21 scans the temperature LUT in the x-axis direction centering on the nth pixel, and sets a range in which pixels illuminated with the luminance equal to the luminance obtained in S45 are continuous as the nth region. Specify (S46). Note that the calculation unit 21 in S46 may be configured to specify, as the nth region, a range in which pixels illuminated with a predetermined range of luminance including the luminance obtained in S45 are continuous.

Referring to FIG. 2, an example of the nth area is a rectangular display area (one rectangular display area in which the LED 321 is turned off) including coordinates (x ₁ , y ₁ ). Another example of the n-th region is a rectangular display region including coordinates (x ₂ , y ₁ ) and a rectangular display region including coordinates (x ₃ , y ₁ ) ( _two illuminated with luminance L ₂ Rectangular display area).

Next, the computing unit 21 determines whether or not there is an estimated pixel other than the nth pixel (hereinafter also referred to as another estimated pixel) in the nth region specified in S46 in the temperature LUT ( S47).
When the estimated pixel included in the n-th region is only the n-th pixel (NO in S47), the calculation unit 21 adds the n-th pixel to each non-estimated pixel included in the n-th region in the temperature LUT. The estimated temperature is written (S48). Hereinafter, the non-estimated pixel in which the estimated temperature is written in the process of S48 is referred to as a temporary estimated pixel.

When there is an estimated pixel other than the nth pixel in the nth region specified in S46 (YES in S47), the calculation unit 21 calculates the estimated temperature of the nth pixel (S49). The calculation unit 21 in S49 calculates the average value of the estimated temperature of the nth pixel and the estimated temperature of other estimated pixels, and sets the calculation result as the estimated temperature of the nth pixel. However, the estimated temperature obtained in S49 is not significantly different from the estimated temperature of the nth pixel.
In addition, the calculating part 21 in S49 is not limited to the structure which calculates an average value, The structure which calculates the maximum value, the minimum value, or the mode value etc. may be sufficient.

Next, the calculation unit 21 writes the calculation result of S49 to each of the non-estimated pixel and the estimated pixel included in the nth region in the temperature LUT (S50). In the process of S50, the non-estimated pixel in which the estimated temperature as the calculation result of S49 is written is also referred to as a temporary estimated pixel below.
After the process of S48 is completed or after the process of S50 is completed, the calculation unit 21 determines whether there are still unestimated pixels in the jth line (S51).
When an unestimated pixel exists in the j-th line (YES in S51), the calculation unit 21 adds “1” to the x coordinate value of the pixel having the largest x coordinate value among the pixels included in the nth region. The added result is substituted into the variable m (S52), and then the calculation unit 21 increments the variable n by “1” (S53), and returns the process to S42.

When only the estimated pixel and the temporary estimated pixel exist in the j-th line (NO in S51), as shown in FIG. 7, the calculation unit 21 resets the variable h to “1” (S61), and the temperature Referring to the LUT, the absolute value of the difference between the estimated temperature T _hj of the h-th pixel and the estimated temperature T _{h + 1j} of the h + 1-th pixel is calculated (S62). Hereinafter, the calculation result of S62 is referred to as a temperature difference ΔT. That is, the calculation unit 21 in S62 performs calculation using the following equation (2).
ΔT = | T _hj −T _{h + 1j} | (2)

Next, as will be described later, the calculation unit 21 calculates a range k at the boundary between the h-th region and the h + 1-th region (S63).
In the present embodiment, the calculation unit 21 calculates the boundary range k in the h-th region or the boundary range k in the h + 1 region (see FIG. 2). A range k indicates a distance from a boundary position between the h-th region and the h + 1-th region. The calculation unit 21 in S63 calculates the range k by substituting the temperature difference ΔT calculated in S62 for a variable Δt included in the following equation (3).
k = f (Δt) (3)

Here, the function f (Δt) is an appropriate function depending on at least the heat transfer rate in the liquid crystal display panel 12. Note that the function f (Δt) may be a function that depends on the heat transfer rate, the luminance difference of the backlight 32 that irradiates the hth region and the h + 1 region, and the like. In addition, the calculation unit 21 uses a function for calculating the boundary range k _h in the h-th region and the boundary range k _{h + 1} in the h + 1 region, instead of the function f (Δt). Also good.

In FIG. 2, the first area is a rectangular display area including coordinates (x ₁ , y ₁ ). The second area is a rectangular display area including coordinates (x ₂ , y ₁ ) and a rectangular display area including coordinates (x ₃ , y ₁ ).
The computing unit 21 in S62 and S63 computes the range k by computing the following equation (4) and substituting the computation result into the variable Δt in the equation (3).
ΔT = | T ₁₁ −T ₂₁ | (4)

Among the x coordinate values of the pixels located in the first area, the maximum x coordinate value x _max1 is the x coordinate value x ₁ +2, and is the smallest of the x coordinate values of the pixels located in the second area. The x coordinate value x _min2 is the x coordinate value x ₂ -2.
The boundary position between the first area and the second area is coordinates ({x _max1 + x _min2 } / 2, y ₁ ). Therefore, the range from the coordinate ({x _max1 + x _min2 } / 2−k, y ₁ ) to the coordinate ({x _max1 + x _min2 } / 2 + k, y ₁ ) is the boundary between the h th region and the h + 1 th region. is there.

  After the process of S63 ends, the calculation unit 21 determines whether or not the range k is “0.5” or more (S64). The process of S64 is a process of determining whether or not a pixel is included in the boundary between the h-th area and the h + 1-th area.

  When k ≧ 0.5 (YES in S64), at least one pixel is included in the boundary between the h-th area and the h + 1-th area. Therefore, the calculation unit 21 sets each pixel within the range k included in the h-th region and each pixel within the range k included in the h + 1 region as unestimated pixels (S65), and unestimated pixels at the boundary portion The estimated temperature is calculated again (S66), and the calculation result is written in the temperature LUT (S67).

  The calculation unit 21 in S66 obtains a linear function by using the coordinate value of the boundary position between the h-th region and the h + 1 region, the range k, and the estimated temperatures of the h-th pixel and the h + 1-th pixel, and obtains the linear function obtained. The estimated temperature T is calculated by substituting the x coordinate value X of the unestimated pixel into the function. As described above, in the present embodiment, the calculation unit 21 performs linear approximation in the process of S66, but the calculation unit 21 may perform broken line approximation or curve approximation.

When the process of S66 is executed, the estimated temperature T at the boundary between the first region and the second region shown in FIG. 2 is calculated by the following equations (5) to (9).
X ₁ = {x _max1 + x _min2 } / 2−k (5)
X ₂ = {x _max1 + x _min2 } / 2 + k (6)
T ₁ = T ₁₁ (7)
T ₂ = (T ₂₁ + T ₃₁ ) / 2 (8)
T = {(T ₂ −T ₁ ) / (X ₂ −X ₁ )} X + (T ₁ × X ₂ −T ₂ × X ₁ ) / (X ₂ −X ₁ ) (9)

When the process of S67 ends, the calculation unit 21 moves the process to S68.
When k <0.5 (NO in S64), since the pixel is not included in the boundary between the h-th area and the h + 1-th area, the calculation unit 21 does not execute the processes of S65 to S67. The process proceeds to S68.
Next, the calculation unit 21 determines whether or not the (h + 1) th region is the final region of the j-th line (S68). If it is not the final region (NO in S68), the variable h is incremented by “1”. (S69), the process is returned to S62.
If the (h + 1) th region is the final region of the jth line (YES in S68), the computing unit 21 ends the temperature distribution estimation process and returns the process to the original routine.

  After completion of the processing of S18 shown in FIG. 4 or when at least one of the estimated pixel and the non-estimated pixel does not exist in the j-th line (NO in S17), the calculation unit 21 determines that the j-th line has the temperature LUT. Is not the last line (S19). If it is not the last line (NO in S19), the variable j is incremented by "1" (S20), and the process returns to S16.

  When the j-th line is the final line of the temperature LUT (YES in S19), as shown in FIG. 5, the calculation unit 21 selects the i-th column of the temperature LUT (S31) and scans in the y-axis direction. Then, it is determined whether both the estimated pixel and the non-estimated pixel exist (S32). When both the estimated pixel and the non-estimated pixel exist (YES in S32), the calculation unit 21 calls and executes a subroutine for performing a temperature distribution estimation process for estimating the temperature distribution of the i-th column (S33).

  The subroutine for the temperature distribution estimation process to be called in S33 is substantially the same as the subroutine for the temperature distribution estimation process shown in FIGS. However, in the temperature distribution estimation process shown in FIGS. 6 and 7, various processes are executed in the x-axis direction for the j-th line, but in the temperature distribution estimation process to be called in S33, for the i-th column. Various processes are executed in the y-axis direction. For this reason, detailed description of the subroutine to be called in S33 is omitted.

After the processing of S33 is completed, or when at least one of the estimated pixel and the non-estimated pixel does not exist in the i-th column (NO in S32), the calculation unit 21 determines that the i-th column is the final column of the temperature LUT. (S34), if not the last column (NO in S34), the variable i is incremented by "1" (S35), and the process returns to S31.
When the i-th column is the last column of the temperature LUT (YES in S34), the calculation unit 21 determines whether or not the estimated temperature has been written in all the pixels of the temperature LUT (S36).

When a pixel for which the estimated temperature has not yet been written exists in the temperature LUT (NO in S36), the calculation unit 21 copies the temperature LUT generated at the present time (S37), thereby calculating the first temperature LUT and the first temperature LUT. 2 is generated, and the process returns to S15 shown in FIG.
Thereafter, the calculation unit 21 executes a series of processes S16 to S20 for the first temperature LUT, and executes a series of processes S31 to S35 for the second temperature LUT. As a result, the first temperature LUT describes the temperature distribution estimated by scanning in the x-axis direction, and the second temperature LUT describes the temperature distribution estimated by scanning in the y-axis direction. The

When the estimated temperature has been written to all the pixels of the temperature LUT (YES in S36), the calculation unit 21 averages each pixel value of the first temperature LUT and each pixel value of the second temperature LUT. (S38) A final temperature LUT is generated.
Finally, the calculation unit 21 calls and executes a subroutine (see FIG. 8) for performing correction table selection processing for selecting the correction table R (S39).
After the process of S39 ends, the calculation unit 21 returns the process to S11.

FIG. 8 is a flowchart showing a subroutine of the correction table selection processing procedure executed by the calculation unit 21.
The calculation unit 21 resets the coordinate values x and y to “1” (S71), and reads the estimated temperature T _xy of the coordinates (x, y) with reference to the temperature LUT (S72).
Here, the threshold values T _L1 and T _L2 are appropriate real numbers of T _L1 <T _L2 , and are given to the calculation unit 21 in advance.
The computing unit 21 determines whether or not the estimated temperature T _xy read in S72 is equal to or less than the threshold threshold value T _L1 (S73). If T _xy > T _L1 (NO in S73), the estimated temperature T _xy is It is determined whether or not the threshold value is T _L2 or more (S74).

When T _xy ≦ T _L1 (YES in S73), the calculation unit 21 selects the first correction table R1 (S75).
When T _L1 <T _xy <T _L2 (NO in S74), the calculation unit 21 selects the second correction table R2 (S76).
If T is a _xy ≧ T _L2 (YES in S74), calculation unit 21 selects the third correction table R3 (S77).
When the processing in S75, S76, or S77 is completed, the calculation unit 21 associates the selection signal indicating the type of the correction table R selected in S75, S76, or S77 with the coordinates (x, y), and performs image processing. It outputs to the part 11 (S78).

When the selection signal is input / output for each rectangular block including a plurality of pixels, the estimated temperature to be compared with the threshold values T _L1 and T _{L2 in} the processing of S73 and S74 is included in the rectangular block. The average temperature, the maximum value, the minimum value, or the mode value of the estimated temperature of each pixel.
Further, when the display device 1 has a configuration in which a selection signal is input / output for each frame, the estimated temperature to be compared with the threshold values T _L1 and T _{L2 in} the processing of S73 and S74 is all pixels included in the temperature LUT. The average value, the maximum value, the minimum value, or the mode value of the estimated temperature.

After the processing of S78 is completed, the calculation unit 21 determines whether or not the coordinate value x is greater than or equal to the maximum coordinate value x _max (S79). If x <x _max (NO in S79), the calculation unit 21 determines the coordinate value x. “1” is incremented (S80), and the process returns to S72.
When x ≧ x _max (YES in S79), the calculation unit 21 determines whether or not the coordinate value y is greater than or equal to the maximum coordinate value y _max (S81), and when y <y _max (in S81). NO), the coordinate value x is reset to “1” (S82), the coordinate value y is incremented by “1” (S83), and the process returns to S72.
If y ≧ y _max (YES in S81), the calculation unit 21 ends the correction table selection process and returns the process to the original routine.

The display device 1 as described above is based on the temperature detection results of the N temperature sensors 23, 23,... And the illumination status of each pixel of the liquid crystal display panel 12 by the backlight 32. In addition, a detailed temperature distribution can be obtained.
Further, the correction table R can be appropriately switched for each pixel based on the accurate and detailed temperature distribution of the liquid crystal display panel 12. Therefore, each control value of temporary control data can be corrected appropriately.
As a result, the image quality of the moving image displayed on the liquid crystal display panel 12 can be sufficiently improved.

By the way, the display device 1 turns off the entire display device 1 or turns off the backlight 32 when the temperature of the liquid crystal display panel 12 exceeds a predetermined upper limit temperature in order to suppress adverse effects on each part of the device due to high temperatures. Or a temperature protection function for cooling the liquid crystal display panel 12.
For this purpose, the calculation unit 21 is given in advance a coordinate value corresponding to an arrangement position of a component or circuit that is vulnerable to high temperatures.

For example, during the execution of the correction table selection process illustrated in FIG. 8, the calculation unit 21 determines whether or not the coordinates (x, y) from which the estimated temperature T _xy is read in S72 correspond to an arrangement position of a component or circuit that is vulnerable to high temperatures. Determine whether. If there is a component or circuit that is vulnerable to high temperatures at the coordinate (x, y), and the estimated temperature T _xy exceeds a predetermined upper limit value, the computing unit 21 enables the temperature protection function.

Embodiment 2. FIG.
FIG. 9 is a characteristic diagram showing a temperature distribution of the liquid crystal display panel 12 included in the display device 1 according to Embodiment 2 of the present invention. The characteristic diagram shown in FIG. 9 corresponds to the characteristic diagram shown in FIG. 2 of the first embodiment.
The display device 1 of the present embodiment has substantially the same configuration as the display device 1 of the first embodiment. For this reason, parts corresponding to those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the display device 1 according to the present embodiment, among the rectangular display areas illuminated by the respective LEDs 321, there is a rectangular display area where no temperature sensor 23 is arranged (hereinafter referred to as a non-sensor area).

  When the brightness of the backlight 32 that illuminates the non-sensor area is equal to the brightness of the backlight 32 that illuminates at least one of the rectangular display areas on both sides of the non-sensor area, the image calculation processing shown in FIGS. The temperature of each pixel of the liquid crystal display panel 12 can be estimated in exactly the same procedure.

  However, as shown in FIG. 9, when the luminance of the backlight 32 that illuminates the non-sensor area is different from the luminance of the backlight 32 that illuminates the rectangular display areas on both sides of the non-sensor area, FIG. It is necessary to estimate the temperature of each pixel of the liquid crystal display panel 12 by a similar procedure slightly different from the image calculation processing shown in FIG.

In this case, the calculation unit 21 ignores the non-sensor area and executes the processes of S41 to S63 shown in FIGS. 6 and 7. If YES in S64, it executes the process of S65.
In S66, the calculation unit 21 calculates the coordinate value of the boundary position between the h-th region and the non-sensor region, the coordinate value of the boundary position between the non-sensor region and the h + 1 region, the range k, the h-th pixel, and the h + 1-th pixel. A linear function is obtained using the estimated temperature, and the estimated temperature T is calculated by substituting the x coordinate value X of the unestimated pixel into the obtained linear function. As a result, a graph G3 shown in FIG. 9 is obtained.
After the process of S66 is completed, the calculation unit 21 executes the processes of S67 to S69.

In the case of NO in S64, for example, the calculation unit 21 uses the average value of the estimated temperatures of the h-th pixel and the (h + 1) -th pixel as the estimated temperature of each pixel in the non-sensor area, and executes the processes after S68.
That is, the calculation unit 21 according to the present embodiment calculates the sum of the boundary range k in the hth region, the no-sensor region, and the boundary range k in the h + 1 region, as the hth region and the h + 1 region. And the estimated temperature of each of the h-th pixel and the (h + 1) -th pixel is used to estimate the temperature of each pixel located at the boundary. The same effect as the apparatus 1 is produced.

  In addition, the structure which has a complement means, such as a table or a function which shows the relationship between the brightness | luminance of an unsensor area | region and estimated temperature, may be sufficient as the calculating part 21. In this case, the calculation unit 21 calculates the estimated temperature of the non-sensor area based on the estimated temperatures of the first pixel and the second pixel and the complementing means. Such a complement means may be given to the calculation unit 21 in advance. Or the structure by which the calculating part 21 produces | generates beforehand such a complementing means based on the brightness | luminance and estimated temperature of each 1st pixel and 2nd pixel, and the brightness | luminance of a sensorless area | region may be sufficient.

Embodiment 3. FIG.
FIG. 10 is a block diagram showing a main configuration of the display device 1 according to Embodiment 3 of the present invention. The block diagram shown in FIG. 10 corresponds to the block diagram shown in FIG.
The display device 1 of the present embodiment has substantially the same configuration as the display device 1 of the first embodiment. For this reason, parts corresponding to those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The display device 1 according to the present embodiment further includes a fluctuation detection unit 41, a position filter processing unit 42, an area filter processing unit 43, and a speed filter processing unit 44.

The image receiving unit 10 receives image data transmitted from the image transmitting device to the display device 1 in time series, and the received image data for each frame, an image processing unit 11, a frame memory 14, and a backlight control unit. 31 and the fluctuation detection unit 41.
The image data stored in the frame memory 14 is read from the frame memory 14 when the image data after one frame of the image data is input to the frame memory 14, and the image processing unit 11 and the fluctuation detecting unit 41 respectively.

The user is more likely to pay attention to an area in which the moving image fluctuates more than an area in which the moving image fluctuates small in the entire display area of the liquid crystal display panel 12.
Therefore, the fluctuation detection unit 41 detects the fluctuation amount of each pixel of the current image data based on the difference between the respective pixel values of the current image data and the past image data (see Patent Documents 1 and 2). Such a fluctuation | variation detection part 41 functions as a fluctuation | variation detection means in this invention.
Next, the variation detection unit 41 outputs a table indicating the variation detection result of each pixel to the position filter processing unit 42.

The user is more likely to focus on the central portion than on the peripheral portion of the liquid crystal display panel 12.
Therefore, the position filter processing unit 42 removes pixels located in the peripheral portion of the liquid crystal display panel 12 from the input table. Next, the position filter processing unit 42 outputs to the area filter processing unit 43 a table indicating the result of detecting the variation of the pixels located in the central portion of the liquid crystal display panel 12.

The user is more likely to pay attention to a region where the area of the moving image changes is larger than a region where the area of the moving image changes is smaller.
Therefore, the area filter processing unit 43 refers to the input table, calculates the area of the region where the pixels with similar variation detection results are adjacent, and the area is relatively compared from the input table. Pixels located in a narrow area are removed. Next, the area filter processing unit 43 outputs to the speed filter processing unit 44 a table indicating the variation detection result of pixels located in a region having a relatively large area.

The user is more likely to focus on an area where the moving image is changing faster than an area where the moving image is changing more slowly.
Therefore, the speed filter processing unit 44 removes pixels having a fluctuation detection result equal to or less than a predetermined value from the input table. Next, the speed filter processing unit 44 outputs a table having the fluctuation detection results of the remaining pixels to the calculation unit 21.
The data amount of the table output from the speed filter processing unit 44 is smaller than the data amount of the table output from the fluctuation detection unit 41. Accordingly, it is possible to reduce the calculation load in the subsequent stage.

The computing unit 21 determines the final temperature LUT generated by the process of S38 shown in FIG. 5 of the first embodiment according to the magnitude of the fluctuation detection result shown in the table input from the speed filter processing unit 44. Weight. In this case, the estimated temperature of a pixel having a large variation detection result is heavily weighted, the estimated temperature of a pixel having a small variation detection result is weighted small, and the estimated temperature of a pixel not corresponding to the variation detection result is not weighted.
Thereafter, the arithmetic unit 21 executes the process of S39 shown in FIG. 5 as in the first embodiment.
At this time, the image processing unit 11 generates temporary control data, and corrects the generated temporary control data while switching the correction table R for each pixel.

Alternatively, the calculation unit 21 refers to the input table and estimates an estimated temperature of a pixel having the largest variation detection result or an estimated temperature obtained by averaging estimated temperatures of pixels included in a block having the largest variation detection result. Is obtained from the final temperature LUT generated in the process of S38 shown in FIG. 5 of the first embodiment.
In this case, the process of S39 shown in FIG. 5 is not executed. Instead, the calculation unit 21 executes processing corresponding to the processing of S73 to S77 shown in FIG. 8 of the first embodiment based on the estimated temperature acquired from the final temperature LUT, and the selected correction table R A selection signal indicating the type is output to the image processing unit 11.
At this time, the image processing unit 11 generates temporary control data, and corrects the generated temporary control data while referring to only one of the correction tables R.

  In the display device 1 as described above, it is possible to sufficiently improve the image quality of the portion that is most easily noticed by the user. Even if the image quality of the portion that is not noticed by the user is hardly improved, it does not matter.

By the way, the calculating part 21 in Embodiments 1-3 considers the backlight 32 as a heat source, and estimates the temperature of the liquid crystal display panel 12. However, the backlight 32 is not the only heat source disposed in the vicinity of the liquid crystal display panel 12. Examples of such a heat source include a power supply circuit that supplies power to each unit of the display device 1.
Therefore, it is conceivable to give the arrangement position of each heat source to the calculation unit 21 in advance. In this case, a more accurate temperature distribution can be obtained by correcting the estimated temperature of each pixel described in the generated temperature LUT based on the arrangement position of each heat source.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not intended to include the above-described meanings, but is intended to include meanings equivalent to the claims and all modifications within the scope of the claims. For example, in the present embodiment, a liquid crystal display device is exemplified as the display device 1, but the present invention is not limited to this.
Moreover, as long as the effect of the present invention is obtained, the display device 1 may include components that are not disclosed in the first to third embodiments.

DESCRIPTION OF SYMBOLS 1 Display apparatus 11 Image processing part 12 Liquid crystal display panel (display panel)
21 Calculation unit (temperature estimation means, selection means)
23 Temperature Sensor 32 Backlight 41 Fluctuation Detection Unit (Fluctuation Detection Unit)
R1 first correction table (generating means)
R2 Second correction table (generating means)
R3 Third correction table (generation means)

Claims (4)

A display panel for displaying a moving image according to control data generated based on time-series input image data;
A backlight for individually illuminating each part of the display panel;
A plurality of temperature sensors that respectively detect the temperature of the arrangement position;
In a display device comprising a plurality of types of generating means for generating the control data,
Temperature estimation means for estimating the temperature of each pixel of the display panel based on the detection result of each of the temperature sensors and the illumination status of each pixel of the display panel by the backlight;
Selecting means for selecting any one of the generating means based on the estimation result of the temperature estimating means,
The display device is characterized in that the control data is generated using the generation means selected by the selection means. The temperature estimating means includes
Means for estimating a temperature of a pixel corresponding to an arrangement position of the temperature sensor based on a detection result of each temperature sensor;
At the boundary between the first region where the pixels illuminated by the backlight with the first luminance are adjacent to each other and the second region where the pixels illuminated by the backlight with the second luminance different from the first luminance are adjacent to each other The temperature of each pixel positioned is included in the first region and the temperature of the first pixel whose temperature has already been estimated, and the second pixel that is included in the second region and whose temperature has already been estimated Means for estimating based on the temperature of
Means for estimating a temperature of a pixel excluding a pixel located at the boundary included in the first region based on a temperature of the first pixel;
The display device according to claim 1, further comprising: means for estimating a temperature of a pixel excluding a pixel located in the boundary portion included in the second region based on a temperature of the second pixel. It further comprises a change detection means for detecting a change in a moving image displayed on the display panel,
3. The selection unit according to claim 1, wherein the selection unit selects any one of the generation units based on an estimation result of the temperature estimation unit and a detection result of the fluctuation detection unit. Display device. A display panel for displaying a moving image according to control data generated based on time-series input image data;
A backlight for individually illuminating each part of the display panel;
A plurality of temperature sensors that respectively detect the temperature of the arrangement position;
In a display method for displaying a moving image on a display device comprising a plurality of types of generating means for generating the control data,
Based on the detection result of each of the temperature sensors and the illumination status of each pixel of the display panel by the backlight, the temperature of each pixel of the display panel is estimated,
Based on the estimated temperature, select one of the generating means,
A display method characterized in that the control data is generated using the selected generation means.

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