JP2015082023A - Display device, electronic apparatus, and driving method of display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device, electronic apparatus, and driving method of a display device with which unevenness of luminance of a specific part can be reduced in controlling the brightness independently for each light source of a side light source.SOLUTION: A display device stores a correction look-up table for each light source obtained by suppressing, with respect to a look-up table for each light source having information on a light intensity distribution in which a plane of an image display panel is irradiated with incident light made incident from light sources from a light guide plate, a peak component of the light intensity distribution when all the light sources are lit at the same degree of light source lighting quantity; and controls the light source lighting quantity of the light sources on the basis of information on the correction look-up table for each light source and an input signal of an image.

Description

  The present invention relates to a display device, an electronic apparatus, and a display device driving method.

  In recent years, the demand for display devices for mobile devices such as mobile phones and electronic paper has increased. In a display device, one pixel includes a plurality of sub-pixels, each of the plurality of sub-pixels outputs light of a different color, and the display of the sub-pixel is switched on and off, so that one pixel can perform various operations. The color is displayed. Such display devices have improved display characteristics such as resolution and luminance year by year. However, since the aperture ratio decreases as the resolution increases, there is a problem that, when trying to achieve high luminance, it is necessary to increase the luminance of the backlight, and the power consumption of the backlight increases. In order to improve this, there is a technique of adding a white pixel as a fourth subpixel to a conventional red, green, and blue subpixel (for example, Patent Document 1). This technology reduces the current value of the backlight and the power consumption by the amount that the white pixel improves the luminance.

  Further, in Patent Document 2, a target luminance value that is not uniform over the entire surface of the display panel is set as a target luminance value for the video signal value so that the distribution of the target luminance value for each display panel plane position is a curved distribution. The technology to do is described.

JP 2010-33014 A JP 2010-127994 A

  When the technique of Patent Document 2 is applied to a sidelight light source in which at least one side surface of a light guide plate is an incident surface and a plurality of independently controlled light sources are arranged at a position facing the incident surface, Since the luminance distribution changes in a complicated manner, it cannot be applied.

  An object of the present disclosure is to provide a display device, an electronic device, and a driving method of the display device that can reduce luminance unevenness in a specific portion when controlling brightness independently for each light source of a sidelight light source.

  The display device according to this aspect includes an image display panel, a light guide plate that illuminates the image display panel from the back, and at least one side surface of the light guide plate as an incident surface, and a plurality of light sources at positions facing the incident surface. A planar light source comprising: an arrayed sidelight light source; and a control unit that controls brightness independently for each light source, wherein the control unit receives incident light from the light source from the light guide plate. A light source that suppresses the peak component of the light intensity distribution when all the light sources are turned on with the same light source lighting amount with respect to the lookup table for each light source having information on the light intensity distribution irradiated on the plane of the image display panel A separate correction lookup table is stored, and the light source lighting amount of each light source is controlled based on the correction lookup table for each light source and information on the input signal of the image.

  The electronic apparatus according to this aspect includes the display device according to this aspect described above.

  The display device driving method according to this aspect includes a plurality of image display panels, a light guide plate that illuminates the image display panel from the back, and at least one side surface of the light guide plate as an incident surface, at a position facing the incident surface. A planar light source comprising: a sidelight light source in which light sources are arranged; and a display device driving method comprising: an input signal detection step for detecting an input signal of an image; and an image analysis step for analyzing the image And with respect to a look-up table for each light source having information on a light intensity distribution in which incident light incident from the light source is irradiated onto the plane of the image display panel from the light guide plate, all the light sources have similar light source lighting amounts. Light source lighting amount calculation that calculates the light source lighting amount of the light source from the correction look-up table for each light source that suppresses the peak component of the intensity distribution when turned on, and the result of the analysis of the image Includes a step, a.

  According to the present disclosure, it is possible to provide a display device, an electronic apparatus, and a display device driving method that can reduce luminance unevenness in a specific portion when controlling brightness independently for each light source of a sidelight light source.

FIG. 1 is a block diagram illustrating an example of a configuration of a display device according to the present embodiment. FIG. 2 is a diagram showing a pixel array of the image display panel according to the present embodiment. FIG. 3 is an explanatory diagram of the light guide plate and the sidelight light source according to the present embodiment. FIG. 4 is an explanatory diagram illustrating an example of an intensity distribution of light acting by one light source of the sidelight light source according to the present embodiment. FIG. 5 is an explanatory diagram for explaining an example of the intensity distribution of light acted by one light source of the sidelight light source according to the present embodiment. FIG. 6 is a conceptual diagram of a reproduction HSV color space that can be reproduced by the display device of the present embodiment. FIG. 7 is a conceptual diagram showing the relationship between the hue and saturation of the reproduction HSV color space. FIG. 8 is a block diagram for explaining the signal processing unit according to the present embodiment. FIG. 9 is a flowchart of the driving method of the display device according to the present embodiment. FIG. 10 is a schematic diagram for explaining information of light intensity distribution in which incident light incident from a specific light source is irradiated from the light guide plate onto the plane of the image display panel. FIG. 11 is a schematic diagram for explaining a lookup table for each light source. FIG. 12 is an explanatory diagram for explaining the calculation of linear interpolation. FIG. 13 is an explanatory diagram for explaining the calculation of polynomial interpolation. FIG. 14 is a flowchart for explaining a process for correcting luminance unevenness according to the present embodiment. FIG. 15 is an explanatory diagram for explaining the intensity distribution of the light incident on the plane of the image display panel from the light guide plate when the incident light enters when all the light sources according to the present embodiment are turned on with the same light source lighting amount. FIG. FIG. 16 is an explanatory diagram for explaining a correction table according to the present embodiment. FIG. 17 is an explanatory diagram for explaining the reciprocal distribution of the correction table according to the present embodiment. FIG. 18 is an explanatory diagram for describing a lookup table for each light source according to the present embodiment. FIG. 19 is an explanatory diagram for explaining a correction lookup table for each light source according to the present embodiment. FIG. 20 is an explanatory diagram for explaining the luminance distribution of the image display panel according to the present embodiment. FIG. 21 is an explanatory diagram for explaining the luminance distribution of the image display panel according to the comparative example. FIG. 22 is an explanatory diagram for explaining the inverse distribution of FIG. FIG. 23 is an explanatory diagram for explaining the luminance distribution of the image display panel according to the comparative example. FIG. 24 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 25 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 26 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 27 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 28 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 29 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 30 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 31 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied. FIG. 32 is a diagram illustrating an example of an electronic apparatus to which the display device according to this embodiment is applied.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Configuration of display device)
FIG. 1 is a block diagram illustrating an example of a configuration of a display device according to the present embodiment. FIG. 2 is a diagram showing a pixel array of the image display panel according to the present embodiment.

  As shown in FIG. 1, the display device 10 receives an image input signal SRGB from the image output unit 11, sends an output signal SRGBW to each unit of the display device 10, and a signal processing unit 20 that controls the operation, An image display panel (display unit) 30 that displays an image based on the output signal SRGBW output from the processing unit 20, an image display panel drive unit 40 that controls driving of the image display panel 30, and the image display panel 30 on the back side A planar light source device 50 that illuminates the surface light source, and a planar light source device controller 60 that controls the driving of the planar light source device 50. The display device 10 has the same configuration as the image display device assembly described in Japanese Patent Application Laid-Open No. 2011-154323 in Patent Literature, and various modifications described in Japanese Patent Application Laid-Open No. 2011-154323. Is applicable.

  The signal processing unit 20 is an arithmetic processing unit that controls operations of the image display panel 30 and the planar light source device 50. The signal processing unit 20 is connected to an image display panel driving unit 40 for driving the image display panel 30 and a planar light source device control unit 60 for driving the planar light source device 50. The signal processing unit 20 processes an input signal input from the outside to generate an output signal and a planar light source device control signal. That is, the signal processing unit 20 reproduces an input value (input signal) of the input HSV color space of the input signal in the first color, the second color, the third color, and the fourth color. It is generated by converting to a reproduction value (output signal) of the space, and the generated output signal is output to the image display panel 30. The signal processing unit 20 outputs the generated output signal to the image display panel driving unit 40 and outputs the generated planar light source device control signal to the planar light source device control unit 60.

As shown in FIG. 1, the image display panel 30 has pixels 48 arranged in P ₀ × Q ₀ (P _{0 in} the row direction and Q _{0 in} the column direction) in a two-dimensional matrix (matrix). Has been. The example shown in FIG. 1 shows an example in which a plurality of pixels 48 are arranged in a matrix in an XY two-dimensional coordinate system. In this example, the row direction is the X direction and the column direction is the Y direction.

  The pixel 48 includes a first sub pixel 49R, a second sub pixel 49G, a third sub pixel 49B, and a fourth sub pixel 49W. The first sub-pixel 49R displays a first primary color (for example, red). The second subpixel 49G displays a second primary color (for example, green). The third subpixel 49B displays a third primary color (for example, blue). The fourth subpixel 49W displays a fourth color (specifically, white). As described above, the pixels 48 arranged in a matrix on the image display panel 30 include the first sub-pixel 49R that displays the first color, the second sub-pixel 49G that displays the second color, and the third color. It includes a third sub-pixel 49B for displaying and a fourth sub-pixel 49W for displaying a fourth color. The first color, the second color, the third color, and the fourth color are not limited to the first primary color, the second primary color, the third primary color, and the white color, and may be different colors such as complementary colors. The fourth sub-pixel 49W that displays the fourth color, when irradiated with the same light source lighting amount, the first sub-pixel 49R that displays the first color, the second sub-pixel 49G that displays the second color, It is preferable to be brighter than the third sub-pixel 49B that displays the third color. Hereinafter, the first sub-pixel 49R, the second sub-pixel 49G, the third sub-pixel 49B, and the fourth sub-pixel 49W are referred to as sub-pixels 49 when it is not necessary to distinguish them from each other.

  More specifically, the display device 10 is a transmissive color liquid crystal display device. As shown in FIG. 2, the image display panel 30 is a color liquid crystal display panel, and a first color filter that passes the first primary color is disposed between the first sub-pixel 49R and the image observer, and the second sub-pixel is arranged. A second color filter that passes the second primary color is arranged between the pixel 49G and the image observer, and a third color filter that passes the third primary color is arranged between the third sub-pixel 49B and the image observer. ing. In the image display panel 30, no color filter is disposed between the fourth sub-pixel 49W and the image observer. The fourth subpixel 49W may be provided with a transparent resin layer instead of the color filter. As described above, by providing the transparent resin layer, the image display panel 30 can suppress the occurrence of a large step in the fourth subpixel 49W by not providing the color filter in the fourth subpixel 49W.

  The image display panel drive unit 40 shown in FIGS. 1 and 2 is included in the control unit of the present embodiment, and includes a signal output circuit 41 and a scanning circuit 42. The image display panel driving unit 40 holds the video signal by the signal output circuit 41 and sequentially outputs it to the image display panel 30. The signal output circuit 41 is electrically connected to the image display panel 30 through a signal line DTL. The image display panel driving unit 40 selects a subpixel in the image display panel 30 by the scanning circuit 42 and controls a switching element (for example, a thin film transistor (TFT)) for controlling the operation (light transmittance) of the subpixel. )) On and off. The scanning circuit 42 is electrically connected to the image display panel 30 by the scanning line SCL.

  The planar light source device 50 is disposed on the back surface of the image display panel 30 and illuminates the image display panel 30 by irradiating light toward the image display panel 30. FIG. 3 is an explanatory diagram of the light guide plate and the sidelight light source according to the present embodiment. The planar light source device 50 includes a light guide plate 54 and a plurality of light sources 56A, 56B, 56C, 56D, 56E, and 56F at positions facing the entrance surface E with at least one side surface of the light guide plate 54 as an entrance surface E. And arranged sidelight light sources 52. The plurality of light sources 56A, 56B, 56C, 56D, 56E, and 56F are, for example, light emitting diodes (LEDs) of the same color (for example, white). The plurality of light sources 56A, 56B, 56C, 56D, 56E, and 56F are arranged along one side surface of the light guide plate 54, and the light source arrangement direction in which the light sources 56A, 56B, 56C, 56D, 56E, and 56F are arranged is LY. In this case, incident light from the light sources 56A, 56B, 56C, 56D, 56E, and 56F enters the light guide plate 54 from the incident surface E in the light incident direction LX orthogonal to the light source arrangement direction LY.

  The planar light source device controller 60 controls the amount of light output from the planar light source device 50. The planar light source device controller 60 is included in the controller of this embodiment. Specifically, the planar light source device control unit 60 adjusts the current or duty ratio (duty ratio) supplied to the planar light source device 50 based on the planar light source device control signal SBL output from the signal processing unit 20. As a result, the amount of light (light intensity) irradiating the image display panel 30 is controlled. Then, the planar light source device controller 60 controls the current or the duty ratio (duty ratio) independently for each of the plurality of light sources 56A, 56B, 56C, 56D, 56E and 56F shown in FIG. It is possible to perform split drive control of the light source that controls the amount of light (light intensity) emitted by the light sources 56A, 56B, 56C, 56D, 56E, and 56F.

  FIG. 4 and FIG. 5 are explanatory diagrams for explaining an example of the intensity distribution of light acted on by one light source of the sidelight light source according to the present embodiment. FIG. 4 shows information on light intensity distribution in which incident light incident from the light source 56A is irradiated from the light guide plate 54 onto the plane of the image display panel 30 when only the light source 56A shown in FIG. When the incident light of the light source 56A enters the light guide plate 54 from the incident surface E to the light guide plate 54 in the light incident direction LX orthogonal to the light source arrangement direction LY, the light guide plate 54 illuminates the image display panel 30 from the back. Irradiate in the illumination direction LZ. In the present embodiment, the illumination direction LZ is orthogonal to the light source arrangement direction LY and the light incident direction LX.

  FIG. 4 shows information on the light intensity distribution in which incident light incident from the light source 56C is irradiated from the light guide plate 54 onto the plane of the image display panel 30 when only the light source 56C shown in FIG. When the incident light of the light source 56C enters the light guide plate 54 from the incident surface E to the light guide plate 54 in the light incident direction LX orthogonal to the light source arrangement direction LY, the light guide plate 54 illuminates the image display panel 30 from the back. Irradiate in the illumination direction LZ.

  Since the light guide plate 54 reflects light at both end faces appearing in the light source arrangement direction LY, the light intensity distribution of the light source 56A and the light source 56F that is close to both end faces appearing in the light source arrangement direction LY, the light source 56A, and the light source For example, the intensity distribution of the light emitted between the light sources 56C disposed between the light sources 56F is different. For this reason, as will be described later, the planar light source device controller 60 according to the present embodiment independently supplies current or current independently to the light sources 56A, 56B, 56C, 56D, 56E, and 56F shown in FIG. It is necessary to control the duty ratio (duty ratio) and to control the amount of light (light intensity) to be irradiated according to the light intensity distribution of each of the light sources 56A, 56B, 56C, 56D, 56E, and 56F. Next, processing operations executed by the display device 10, more specifically, the signal processing unit 20, will be described.

(Processing of display device)
FIG. 6 is a conceptual diagram of a reproduction HSV color space that can be reproduced by the display device of the present embodiment. FIG. 7 is a conceptual diagram showing the relationship between the hue and saturation of the reproduction HSV color space. FIG. 8 is a block diagram for explaining the signal processing unit according to the present embodiment. As shown in FIG. 1, the signal processing unit 20 receives an input signal SRGB that is image information to be displayed from an external image output unit 11. FIG. 9 is a flowchart of the driving method of the display device according to the present embodiment. The input signal SRGB includes information of an image (color) displayed at the position for each pixel as an input signal. Specifically, in the image display panel 30 in which P ₀ × Q ₀ pixels 48 are arranged in a matrix, the (p, q) -th pixel 48 (where 1 ≦ p ≦ P ₀ , 1 ≦ q ≦ Q ₀ ), the input signal of the first subpixel 49R whose signal value is x _{1− (p, q)} , the input signal of the second subpixel 49G whose signal value is x _{2− (p, q)} , and A signal including an input signal (see FIG. 1 ₎ of the third subpixel 49B having a signal value of x _{3- (p, q)} is input to the signal processing unit 20. As shown in FIG. 8, the signal processing unit 20 includes a timing generation unit 21, an image processing unit 22, an image analysis unit 23, a light source drive calculation unit 24, a light source data storage unit 25, and a light source drive value determination unit. 26.

The signal processing unit 20 shown in FIGS. 1 and 8 detects the input signal SRGB as shown in FIG. 9 (step S11). Then, the timing generation unit 21 processes the input signal SRGB to drive the synchronization signal STM for synchronizing the timings of the image display panel drive unit 40 and the planar light source device control unit 60 for each frame to the image display panel drive. To the unit 40 and the planar light source device controller 60. The image processing unit 22 of the signal processing unit 20 processes the input signal SRGB to thereby determine the output signal of the first subpixel (signal value X _{1- (p, q)} ), the output signal of the second subpixel (signal value _{X2- (p, q)} ) for determining the display gradation of the second subpixel 49G, and the display gradation of the third subpixel 49B. Output signal (signal value X _{3- (p, q)} ) for the fourth sub-pixel and signal output from the fourth sub-pixel for determining the display gradation of the fourth sub-pixel 49W (signal value X _{4- ( p, q)} ) is generated, and the display data calculation step (step S16) to be output to the image display panel drive unit 40 is processed. Hereinafter, the calculation step (step S16) of the display data according to the present embodiment will be described in detail.

  The display device 10 includes the fourth sub-pixel 49W that outputs the fourth color (white) to the pixel 48, thereby providing a dynamic range of brightness in the HSV color space (reproduction HSV color space) as shown in FIG. Can be spread. That is, as shown in FIG. 6, the maximum value of the brightness V increases as the saturation S increases in the cylindrical HSV color space that can be displayed by the first subpixel 49R, the second subpixel 49G, and the third subpixel 49B. It becomes a shape on which a solid body having a substantially trapezoidal shape with a low value is placed.

  The image processing unit 22 of the signal processing unit 20 adds the fourth color (white), so that the maximum value Vmax (S) of the brightness with the saturation S in the expanded HSV color space as a variable is the signal processing unit. 20 is stored. That is, the signal processing unit 20 stores the value of the maximum brightness value Vmax (S) for each coordinate (value) of the saturation S and the hue H with respect to the three-dimensional shape of the HSV color space shown in FIG. Since the input signal includes the input signals of the first sub-pixel 49R, the second sub-pixel 49G, and the third sub-pixel 49B, the HSV color space of the input signal has a cylindrical shape, that is, a cylindrical portion of the reproduction HSV color space. It becomes the same shape.

Next, the image processing unit 22 of the signal processing unit 20 outputs the output of the first sub-pixel 49R based on at least the input signal (signal value x _{1-(p, q)} ) of the first sub-pixel 49R and the expansion coefficient α. A signal (signal value X _{1- (p, q)} ) is calculated and output to the first sub-pixel 49R. Further, the signal processing unit 20 outputs an output signal (signal value X ₂₋ ) of the second sub-pixel 49G based on at least the input signal (signal value x _{2− (p, q)} ) and the expansion coefficient α of the second sub-pixel 49G. _{(P, q)} ) is calculated and output to the second sub-pixel 49G. The signal processing unit 20 has at least an input signal (signal value _{x 3- (p, q))} of the third sub-pixel 49B and the output signal of the third sub-pixel 49B based on the expansion coefficient alpha (signal value _{X 3- (P, q)} ) is calculated and output to the third sub-pixel 49B. Further, the signal processing unit 20, an input signal of the first sub-pixel 49R (signal value _{x 1- (p, q))} , the input signal of the second sub-pixel 49G (signal value _{x 2- (p, q))} and Based on the input signal (signal value x _{3-(p, q)} ) of the third sub-pixel 49B, the output signal (signal value X _{4- (p, q)} ) of the fourth sub-pixel 49W is calculated _, and the fourth sub-pixel is calculated. Output to the pixel 49W.

  Specifically, the image processing unit 22 of the signal processing unit 20 calculates the output signal of the first subpixel 49R based on the expansion coefficient α of the first subpixel 49R and the output signal of the fourth subpixel 49W, and Based on the expansion coefficient α of the second subpixel 49G and the output signal of the fourth subpixel 49W, the output signal of the second subpixel 49G is calculated, and the expansion coefficient α of the third subpixel 49B and the output signal of the fourth subpixel 49W Based on the above, the output signal of the third sub-pixel 49B is calculated.

That is, the signal processing unit 20 sets (p, q) -th pixel (or first sub-pixel 49R, second sub-pixel 49G, and third sub-pixel 49B as a set when χ is a constant depending on the display device. ), The signal value X _{1- (p, q)} that is the output signal of the first sub-pixel 49R, the signal value X _{2- (p, q)} that is the output signal of the second sub-pixel 49G, and the third sub-pixel 49B. The signal value X _{3- (p, q)} that is the output signal of is obtained from the following equations (1) to (3).

_{X1- (p, q)} = [alpha] .x1- _{(p, q)-[} chi] .X4- _{(p, q)} (1)

_{X2- (p, q)} = [alpha] .x2- _{(p, q)-[} chi] .X4- _{(p, q)} (2)

X _{3-(p, q)} = α · x _{3-(p, q)} -χ · X _{4-(p, q)} (3)

  The signal processing unit 20 obtains the maximum value Vmax (S) of the brightness with the saturation S in the HSV color space expanded by adding the fourth color as a variable, and the input signal of the sub-pixel 49 in the plurality of pixels 48. Based on the values, the saturation S and the lightness V (S) in the plurality of pixels 48 are obtained.

Saturation S and lightness V (S) are represented by S = (Max−Min) / Max and V (S) = Max. The saturation S can take a value from 0 to 1, and the lightness V (S) can take a value from 0 to (2 ⁿ −1). n is the number of display gradation bits. Further, Max is the maximum value among the input signal value of the first sub-pixel 49R, the input signal value of the second sub-pixel 49G, and the input signal value of the third sub-pixel 49B to the pixel 48. Min is the minimum value among the input signal value of the first sub-pixel 49R, the input signal value of the second sub-pixel 49G, and the input signal value of the third sub-pixel 49B to the pixel 48. Further, the hue H is represented by 0 ° to 360 ° as shown in FIG. From 0 ° to 360 °, the colors are red (Red), yellow (Yellow), green (Green), cyan (Cyan), blue (Blue), magenta (Magenta), and red.

In the present embodiment, the signal value X _{4− (p, q)} can be obtained based on the product of Min _{(p, q)} and the expansion coefficient α. Specifically, the signal value X _{4- (p, q)} can be obtained based on the following equation (4). In Expression (4), the product of Min _{(p, q)} and the expansion coefficient α is divided by χ, but the present invention is not limited to this. χ will be described later.

X _{4− (p, q)} = Min _{(p, q)} · α / χ (4)

Generally, in the (p, q) th pixel, the input signal of the first sub-pixel 49R (signal value _{x 1- (p, q))} , the input signal of the second sub-pixel 49G (signal value _{x 2-(p , Q)} ) and the input signal (signal value _{x3- (p, q)} ) of the third sub-pixel 49B, saturation S _{(p, q)} and brightness in the HSV color space of the cylinder V (S) _{(p, q)} can be obtained from the following equations (5) and (6).

S _{(p, q)} = (Max _{(p, q)} −Min _{(p, q)} ) / Max _{(p, q)} (5)

V (S) _{(p, q)} = Max _{(p, q)} (6)

Here, Max _{(p, q)} is an input signal value of three sub-pixels 49 of (x _{1- (p, q)} , x _{2- (p, q)} , x _{3- (p, q)} ). Min _{(p, q)} is an input of three subpixels 49 (x _{1-(p, q)} , x _{2-(p, q)} , x _{3-(p, q)} ) 3 This is the minimum signal value. In this embodiment, n = 8. That is, the number of display gradation bits is 8 bits (the display gradation value is 256 gradations from 0 to 255).

No color filter is arranged in the fourth sub-pixel 49W that displays white. The fourth sub-pixel 49W that displays the fourth color, when irradiated with the same light source lighting amount, the first sub-pixel 49R that displays the first color, the second sub-pixel 49G that displays the second color, Brighter than the third sub-pixel 49B that displays the third color. A signal having a value corresponding to the maximum signal value of the output signal of the first subpixel 49R is input to the first subpixel 49R, and the signal value corresponding to the maximum signal value of the output signal of the second subpixel 49G is input to the second subpixel 49G. When a signal having a value is input and a signal having a value corresponding to the maximum signal value of the output signal of the third subpixel 49B is input to the third subpixel 49B, the pixel 48 or the group of pixels 48 includes The luminance of the aggregate of the first sub-pixel 49R, the second sub-pixel 49G, and the third sub-pixel 49B is BN _1-3 . The luminance of the fourth subpixel 49W when a signal having a value corresponding to the maximum signal value of the output signal of the fourth subpixel 49W is input to the fourth subpixel 49W included in the pixel 48 or the group of pixels 48. Assume that BN ₄ is set. That is, the maximum luminance white is displayed by the aggregate of the first sub-pixel 49R, the second sub-pixel 49G, and the third sub-pixel 49B, and this white luminance is represented by BN _1-3 . Then, when χ is a constant depending on the display device, the constant χ is represented by χ = BN ₄ / BN _1-3 .

Specifically, a signal value x _{1− (p, q) is} input to the aggregate of the first subpixel 49R, the second subpixel 49G, and the third subpixel 49B as an input signal having the next display gradation value. = 255, relative to the signal value _{x 2- (p, q) =} 255, the white luminance _{BN 1-3} at the time when the signal value _{x 3- (p, q) =} 255 is input, the fourth subpixel 49W For example, the luminance BN ₄ when the input signal having the display gradation value 255 is input is 1.5 times. That is, in this embodiment, χ = 1.5.

By the way, when the signal value X _{4- (p, q)} is given by the above-described equation (4), Vmax (S) can be expressed by the following equations (7) and (8).

If S ≦ S ₀ ,
Vmax (S) = (χ + 1) · (2 ⁿ −1) (7)

If S ₀ <S ≦ 1:
Vmax (S) = (2 ⁿ −1) · (1 / S) (8)
Here, S ₀ = 1 / (χ + 1).

  The maximum value Vmax (S) of lightness obtained by adding the fourth color and using the saturation S in the HSV color space as a variable, for example, is given to the signal processing unit 20 as a kind of look. Stored as an uptable. Alternatively, the maximum value Vmax (S) of lightness with the saturation S in the enlarged HSV color space as a variable is obtained in the signal processing unit 20 each time.

Next, signal values X _{1- (p, q)} , X _{2- (p, q)} , X _{3- (p, q)} , X ₄₋ which are output signals at the (p, q) -th pixel 48. _A method for _{obtaining (p, q)} (extension processing) will be described. The next processing is the luminance of the first primary color displayed by (first subpixel 49R + fourth subpixel 49W), the luminance of the second primary color displayed by (second subpixel 49G + fourth subpixel 49W), ( This is performed so as to maintain the luminance ratio of the third primary color displayed by the third subpixel 49B + the fourth subpixel 49W). In addition, the color tone is maintained (maintained). Furthermore, the gradation-luminance characteristics (gamma characteristics, γ characteristics) are maintained (maintained). In addition, when all of the input signal values are zero or small in any one of the pixels 48 or the group of pixels 48, the expansion coefficient α may be obtained without including such a pixel 48 or the group of pixels 48. .

(First step)
First, the signal processing unit 20 obtains the saturation S and the lightness V (S) in the plurality of pixels 48 based on the input signal values of the sub-pixels 49 in the plurality of pixels 48. Specifically, a signal value x _{1− (p, q)} that is an input signal of the first subpixel 49R to the (p, q) th pixel 48, and a signal value that is an input signal of the second subpixel 49G. Based on x _{2- (p, q)} , signal value x _{3- (p, q)} that is an input signal of the third sub-pixel 49B, S _{(p, q)} , V from Formula (7) and Formula (8) (S) _{Find (p, q)} . The signal processing unit 20 performs this process for all the pixels 48.

(Second step)
Next, the signal processing unit 20 obtains the expansion coefficient α (S) based on Vmax (S) / V (S) obtained in the plurality of pixels 48.

  α (S) = Vmax (S) / V (S) (9)

(Third step)
Next, the signal processing unit 20 converts the signal value X _{4- (p, q)} in the (p, q) -th pixel 48 to at least the signal value x _{1- (p, q)} , the signal value x ₂₋ It is determined based on _{(p, q)} and the signal value x _{3- (p, q)} . In the present embodiment, the signal processing unit 20 determines the signal value X _{4− (p, q) based} on Min _{(p, q)} , the expansion coefficient α, and the constant χ. More specifically, as described above, the signal processing unit 20 obtains the signal value X _{4- (p, q) based} on the above equation (4). The signal processing unit 20 obtains a signal value X _{4− (p, q)} in all of the P ₀ × Q ₀ pixels 48.

(4th process)
Thereafter, the signal processing unit 20 converts the signal value X _{1- (p, q)} in the (p, q) -th pixel 48 to the signal value x _{1- (p, q)} , the expansion coefficient α, and the signal value X _{4. - (p, q)} obtained based on, the (p, q) th pixel 48 the signal value _X 2 in _{- (p, q)} and the signal value _{x 2 - (p, q)} , expansion coefficient α and the signal value X _{4- (p, q)} , and the signal value X _{3- (p, q)} at the (p, q) -th pixel 48 is converted to the signal value x _{3- (p, q)} , the expansion coefficient α, and _Obtained based on the signal value X _{4− (p, q)} . Specifically, the signal processing unit 20 outputs the signal value X _{1- (p, q)} , the signal value X _{2- (p, q),} and the signal value X _{3- ( p, q)} is obtained based on the above formulas (1) to (3).

The signal processing unit 20 expands the value of Min _{(p, q)} by the expansion coefficient α as shown in Expression (4). As described above, the value of Min _{(p, q)} is expanded by the expansion coefficient α, so that not only the luminance of the white display subpixel (fourth subpixel 49W) increases, but also the red color as shown in the above equation. The luminance of the display subpixel, the green display subpixel, and the blue display subpixel (corresponding to the first subpixel 49R, the second subpixel 49G, and the third subpixel 49B, respectively) also increases. For this reason, the problem that the dullness of color generate | occur | produces can be avoided. That is, as compared with the case where the value of Min _{(p, q)} is not expanded, the value of Min _{(p, q)} is expanded by the expansion coefficient α, so that the luminance of the entire image becomes α times. Therefore, for example, an image display such as a still image can be performed with high luminance, which is preferable.

  As shown in FIG. 9, the signal processing unit 20 processes the display data calculation step (step S16) and performs image analysis of the input signal SRGB (step S12).

The image analysis unit 23 outputs a signal value X _{1- (p, q)} , a signal value X _{2- (p, q)} , a signal value X _{3- (p, q)} in the (p, q) -th pixel 48 _, and It is analyzed that the signal value X _{4− (p, q)} is expanded α times. For this reason, the display device 10 sets the luminance of the planar light source device 50 to the expansion coefficient in order to obtain the same image luminance as that of the unexpanded image based on the information of the image input signal SRGB. What is necessary is just to reduce based on (alpha). Specifically, a plurality of light sources 56A, 56B, 56C, 56D, so that the light driving value calculation unit 24 and the light driving value determination unit 26 increase the luminance of the planar light source device 50 by (1 / α) times. The current or the duty ratio (duty ratio) may be controlled independently for 56E and 56F.

  FIG. 10 is a schematic diagram for explaining information of light intensity distribution in which incident light incident from a specific light source is irradiated from the light guide plate onto the plane of the image display panel. FIG. 11 is a schematic diagram for explaining a lookup table for each light source. In the light source data storage unit 25, a lookup table (LUT) for each light source, which is data storing representative values of light intensity for each of M arrays in the light source array direction LY and N arrays in the light incident direction LX. : Lookup table). For example, as illustrated in FIG. 11, when only the light source 56 </ b> A illustrated in FIG. 3 is turned on, the incident light incident from the light source 56 </ b> A is irradiated from the light guide plate 54 onto the plane of the image display panel 30. The light intensity distribution information (see FIG. 4) is stored as a lookup table LUTA for each light source. Further, in the light source data storage unit 25, when only the light source 56B shown in FIG. 3 is turned on, the light intensity distribution information on the incident light incident from the light source 56B from the light guide plate 54 to the plane of the image display panel 30 is stored. It is stored as a lookup table LUTB for each light source. Further, in the light source data storage unit 25, when only the light source 56C shown in FIG. 3 is turned on, the light intensity distribution information on the incident light incident from the light source 56C from the light guide plate 54 to the plane of the image display panel 30 is stored. It is stored as a lookup table LUTC for each light source. Further, in the light source data storage unit 25, when only the light source 56D shown in FIG. 3 is turned on, information on the light intensity distribution in which the incident light incident from the light source 56D is irradiated from the light guide plate 54 onto the plane of the image display panel 30 is stored. It is stored as a lookup table LUTD for each light source. In the light source data storage unit 25, when only the light source 56E shown in FIG. 3 is turned on, the light intensity distribution information on the incident light incident from the light source 56E from the light guide plate 54 to the plane of the image display panel 30 is stored. It is stored as a lookup table LUTE for each light source. Further, in the light source data storage unit 25, when only the light source 56F shown in FIG. 3 is turned on, information on the light intensity distribution in which the incident light incident from the light source 56F is irradiated from the light guide plate 54 onto the plane of the image display panel 30 is stored. It is stored as a lookup table LUTF for each light source.

  The look-up tables by light source LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF of this embodiment correspond to each of the light sources 56A, 56B, 56C, 56D, 56E, and 56F. In the lookup table for each light source according to the present embodiment, among the light sources 56A, 56B, 56C, 56D, 56E, and 56F, for example, a set of light sources 56A and 56B, a set of light sources 56C and 56D, and a set of light sources 56E and 56F are provided. You may memorize | store the lookup table classified by light source at the time of lighting simultaneously. As a result, it is possible to save labor for creating a lookup table for each light source and reduce the storage capacity of the light source data storage unit 25. As a result, the integrated circuit that stores the light source data storage unit 25 can be downsized. Further, among the lookup tables by light source LUTA, LUTB, LUTC, LUTD, LUTE and LUTF, the lookup tables by light source LUTA, LUTB and LUTC which are one side of the center line in the light source arrangement direction LY are generated and stored. The other light source look-up tables LUTD, LUTE, and LUTF are axisymmetric with respect to the center line and may be omitted.

  The light source drive value calculation unit 24 refers to the lookup tables for each light source LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF in the light source data storage unit 25, and is close to the (1 / α) value analyzed by the image analysis unit 23. As described above, the light source lighting amounts of the light sources 56A, 56B, 56C, 56D, 56E, and 56F are calculated by superimposing the lookup tables for each light source LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF (step S13). For example, the representative luminance (where 1 ≦ i ≦ N, 1 ≦ j ≦ M) obtained by superimposing the (i, j) th light source look-up tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF is as follows: It can be calculated by equation (10).

  As a result, the light source drive value calculation unit 24 can reduce the amount of calculation by replacing complicated calculation processing with simple reference processing of the lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF for each light source.

  As described above, in order for the image display panel drive unit 40 to display the image display panel 30, a luminance distribution in units of 48 pixels is required. Therefore, the light source drive value determination unit 26 uses the light source lighting amounts of the light sources 56A, 56B, 56C, 56D, 56E, and 56F obtained in step S13 and the light source-specific lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF. Based on this, the luminance distribution in units of 48 pixels is calculated (step S14). In the calculation processing of the luminance distribution of the pixel 48 unit, the luminance information of the pixel 48 unit is calculated by interpolation calculation. As a result, the information for each pixel 48 unit has a very large amount of information, but in this embodiment, the light source-specific lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF are created with the thinned representative values. Therefore, the size of the lookup table can be reduced. Further, the light source driving value determination unit 26 can reduce the calculation load by performing linear interpolation calculation.

  In the luminance information for each pixel 48, the change in the light source arrangement direction LY is steep, and the change in the light incident direction LX is a gentle change. FIG. 12 is an explanatory diagram for explaining the calculation of linear interpolation. FIG. 13 is an explanatory diagram for explaining the calculation of polynomial interpolation. The luminance information in each pixel 48 in the light incident direction LX is subjected to the linear interpolation process shown in FIG. 12, and the luminance information in each pixel 48 in the light source arrangement direction LY is subjected to the polynomial interpolation process shown in FIG. Interpolation calculation. Polynomial interpolation is, for example, cubic interpolation. As a result, the light source-specific lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF need only be M in the light source arrangement direction LY, that is, an added value of at least the number of light sources and the number of light sources. Thereby, the size of the lookup table can be significantly reduced.

  Information on the luminance of each pixel 48 of the image display panel 30 is stored (held) in a lookup table for one side of the center line in the light source arrangement direction LY, and the luminance of the other side is symmetrical with respect to the center line. By using the information, the light source drive value determination unit 26 can significantly reduce the lookup table capacity.

Next, the light source driving value determination unit 26 sends the luminance information for each pixel 48 to the image processing unit 22, and the image processing unit 22 corrects the luminance based on the luminance information for each pixel 48, and The signal value X _{1- (p, q)} , signal value X _{2- (p, q)} , signal value X _{3- (p, q)} and signal value X _{4- (p, q)} A synchronization process for calculating the output signal SRGBW is performed so as to output _q) (step S15). Based on the synchronization signal STM, the image display panel driving unit 40 displays an image on the image display panel 30 for each frame, and the planar light source device control unit 60 uses the light sources 56A, 56B, and 56C of the planar light source device 50. , 56D, 56E and 56F are driven independently.

  As described above, the display device includes the planar light source device 50 that is a planar light source including the image display panel 30, the light guide plate 54, and the sidelight light source 52. As the control unit, the image display panel driving unit 40 and the planar light source device control unit 60 are synchronized according to the calculation of the signal processing unit, and the information of the image input signal SRGB and the lookup tables LUTA, LUTB for each light source, Based on the LUTC, LUTD, LUTE, and LUTF, the light source lighting amounts of the light sources 56A, 56B, 56C, 56D, 56E, and 56F are individually controlled. Thereby, it becomes possible to control so that the total amount of light source lighting of the light sources 56A, 56B, 56C, 56D, 56E, and 56F can be reduced, and the power consumption can be reduced.

  However, even if the luminance information for each pixel 48 is sent to the image processing unit 22 and the image processing unit 22 corrects it based on the luminance information for each pixel 48, the luminance information exceeds the luminance that can be emitted from the planar light source device 50. Therefore, when complete correction is performed, the luminance is made uniform in accordance with the darkest portion of the planar light source device 50, and the image is darkly displayed as a whole. (Power efficiency may be reduced). If the luminance is made uniform in accordance with the darkest part of the planar light source device 50, the power consumption of the display device 10 may increase. Therefore, the display device 10 according to the present embodiment can reduce a portion to be corrected and suppress an increase in power consumption.

  FIG. 14 is a flowchart for explaining a process for correcting luminance unevenness according to the present embodiment. The light source drive value determination unit 26 reads the correction table for all lighting distributions (step S21). FIG. 15 is an explanatory diagram for explaining the intensity distribution of the light incident on the plane of the image display panel from the light guide plate when the incident light enters when all the light sources according to the present embodiment are turned on with the same light source lighting amount. FIG. FIG. 16 is an explanatory diagram for explaining a correction table according to the present embodiment. FIG. 17 is an explanatory diagram for explaining the reciprocal distribution of the correction table according to the present embodiment. FIG. 18 is an explanatory diagram for describing a lookup table for each light source according to the present embodiment. FIG. 19 is an explanatory diagram for explaining a correction lookup table for each light source according to the present embodiment. FIG. 20 is an explanatory diagram for explaining the luminance distribution of the image display panel according to the present embodiment.

  In order not to correct the luminance distribution, it is preferable that the luminance distribution generated by the signal processing unit 20 is apparently uniform. The light intensity distribution when all the light sources are turned on at the same light source lighting amount is the luminance distribution at the time of all lighting, and the light source lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF are all overlaid. The all-lighting look-up table LUTQT shown in FIG. 15 can be calculated. In the all-light-up look-up table LUTQT shown in FIG. 15, brightness unevenness QT having a brightness higher than the overall average brightness is generated near each of the light sources 56A, 56B, 56C, 56D, 56E, and 56F. The luminance unevenness QT is a bright spot that appears as a concentration of luminance, where the presence of the light sources 56A, 56B, 56C, 56D, 56E, and 56F can be recognized. As other luminance unevenness, there is a possibility that line-like bright lines with high luminance appear in a concentrated manner in parallel with the incident light direction LX by turning on the light sources 56A, 56B, 56C, 56D, 56E and 56F.

  The light source drive value calculation unit 24 performs a correction process as a light intensity distribution lookup table LUTQF having a corrected luminance QF in which the region including the peak component of the luminance unevenness QT shown in FIG. The lookup table LUTQF is processed as a correction table LUTQFR shown in FIG. FIG. 18 is a three-dimensional display showing the illumination direction LZ of the light source look-up tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF shown in FIG. As shown in FIG. 14, the light source drive value calculation unit 24 includes the correction table LUTQFR described above for each of the light source lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF shown in FIG. Is used to correct the light source lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF for each light source to obtain light source correction lookup tables LUT AH, LUTBH, LUTCH, LUTDH, LUTEH, and LUTFH. Is performed (step S22). In FIG. 19, the correction lookup table LUTCH for each light source is described as a representative, but the process of multiplying the correction table LUTQFR is performed to correct the lookup tables LUTA, LUTB, LUTD, LUTE, and LUTF for each light source. Similarly, the correction lookup tables for each light source LUTAH, LUTBH, LUTDH, LUTEH and LUTFH are also possible. The correction look-up tables LUTAH, LUTBH, LUTCH, LUTDH, LUTEH, and LUTFH for each light source are partially corrected for luminance near the light sources 56A, 56B, 56C, 56D, 56E, and 56F. As a result, it is possible to output an image subjected to the target correction without a calculation load for correction.

  The light source driving value calculation unit 24 refers to the light source specific correction look-up tables LUTAH, LUTBH, LUTCH, LUTDH, LUTEH, and LUTFH, and sets the light source driving value calculation unit 24 so as to be close to the (1 / α) value analyzed by the image analysis unit 23. The correction look-up tables LUTah, LUTBH, LUTCH, LUTDH, LUTEH, and LUTFH are overlapped to calculate the light source lighting amounts of the light sources 56A, 56B, 56C, 56D, 56E, and 56F. For example, the representative luminance (1 ≦ i ≦ N, 1 ≦ j ≦ M) obtained by superimposing the (i, j) th light source-specific correction lookup tables LUTah, LTBH, LUTCH, LUTDH, LUTEH, and LUTFH is as follows: It can calculate with following formula (11).

  As a result, the light source drive value calculation unit 24 can reduce the amount of calculation by replacing complicated calculation processing with reference processing of a simple correction lookup table for each light source LUTAH, LUTBH, LUTCH, LUTDH, LUTEH, and LUTHF.

  The light source drive value determination unit 26 is based on the light source lighting amounts of the light sources 56A, 56B, 56C, 56D, 56E, and 56F obtained in step S13, and the light source-specific correction lookup tables LUTAH, LUTBH, LUTCH, LUTDH, LUTEH, and LUTFH. Thus, luminance information for each pixel 48 is calculated by interpolation.

Next, the light source driving value determination unit 26 sends the luminance information for each pixel 48 to the image processing unit 22, and the image processing unit 22 corrects the luminance based on the luminance information for each pixel 48, and The signal value X _{1- (p, q)} , signal value X _{2- (p, q)} , signal value X _{3- (p, q)} and signal value X _{4- (p, q) The} output signal SRGBW is calculated so as to output _q) (step S23). Based on the synchronization signal STM, the image display panel driving unit 40 displays an image on the image display panel 30 for each frame, and the planar light source device control unit 60 uses the light sources 56A, 56B, and 56C of the planar light source device 50. , 56D, 56E and 56F are driven independently. The image display panel 30 can display an image in a state where the peak component of the luminance distribution is reduced and the power consumption is suppressed as in the luminance distribution LUTV shown in FIG. The correction lookup table for each light source created by the correction processing in the flowchart shown in FIG. 14 can be configured not to be performed by the light source driving value determination unit 26. For example, by using a correction look-up table for each light source that has already been corrected instead of the look-up table for each light source, it is possible to output an image that has been subjected to the target correction without the computational burden for correction. it can.

  FIG. 21 is an explanatory diagram for explaining the luminance distribution of the image display panel according to the comparative example. As shown in FIG. 21, when the correction is made with the luminance distribution at the time of all lighting shown in FIG. 15, the luminance unevenness can be corrected over the entire area, but like the luminance distribution LUTV1 shown in FIG. The surface light source device 50 cannot generate a luminance higher than the luminance that can be emitted. For this reason, if the light source driving value determination unit 26 tries to perform complete correction, the light source driving value determination unit 26 makes the luminance uniform in accordance with the darkest portion of the planar light source device 50, and the image is darkly displayed as a whole. It is exemplified that the power efficiency is reduced.

  FIG. 22 is an explanatory diagram for explaining the inverse distribution of FIG. FIG. 23 is an explanatory diagram for explaining the luminance distribution of the image display panel according to the comparative example. The reciprocal distribution shown in FIG. 22 is processed into a correction table LUTQTR by processing to take the reciprocal of the light intensity of the lookup table LUTQF shown in FIG. The drive value calculation unit 24 may perform a process of multiplying each of the light source lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF shown in FIG. 18 or FIG. 11 by the correction table LUTQTR. As shown in the luminance distribution LUTV2 in FIG. 23, the power consumption is suppressed, but the luminance unevenness is not corrected.

  As described above, the display device 10 uses the light intensity distribution information that the incident light incident from the light sources 56A, 56B, 56C, 56D, 56E, and 56F is irradiated from the light guide plate 54 onto the plane of the image display panel 30. Each is stored as a lookup table for each light source LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF. In the light source data storage unit 25, the peak component of the light intensity distribution when all the light sources are turned on with the same light source lighting amount with respect to the lookup tables LUTA, LUTB, LUTC, LUTD, LUTE, and LUTF for each light source. The corrected correction lookup tables for each light source LUTAH, LUTBH, LUTCH, LUTDH, LUTEH, and LUTFH are calculated and stored. The display device 10 controls the light source lighting amount of each light source based on the information of the correction lookup tables for each light source LUTAH, LUTBH, LUTCH, LUTDH, LUTEH and LUTFH and the input signal SRGB of the image. According to the display device according to the present embodiment, for example, by performing luminance unevenness correction in the vicinity of the light source, the luminance distribution can be improved without any demerits in terms of power and circuit scale.

(Application example)
Next, an application example of the display device 10 described in this embodiment will be described with reference to FIGS. Hereinafter, this embodiment and a modification will be described as this embodiment. 24 to 32 are diagrams illustrating examples of electronic devices to which the display device according to this embodiment is applied. The display device 10 according to the present embodiment is an electronic device in various fields such as a mobile terminal device such as a mobile phone or a smartphone, a television device, a digital camera, a notebook personal computer, a video camera, or a meter provided in a vehicle. It is possible to apply to. In other words, the display device 10 according to the present embodiment can be applied to electronic devices in all fields that display an externally input video signal or an internally generated video signal as an image or video. The electronic device includes a control device that supplies a video signal to the display device 10 and controls the operation of the display device 10.

(Application example 1)
The electronic device shown in FIG. 24 is a television device to which the display device 10 according to this embodiment is applied. This television apparatus has, for example, a video display screen unit 510 including a front panel 511 and a filter glass 512, and the video display screen unit 510 is the display device 10 according to the present embodiment.

(Application example 2)
The electronic apparatus shown in FIGS. 25 and 26 is a digital camera to which the display device 10 according to the present embodiment is applied. The digital camera includes, for example, a flash light emitting unit 521, a display unit 522, a menu switch 523, and a shutter button 524, and the display unit 522 is the display device 10 according to the present embodiment. As shown in FIG. 25, this digital camera has a lens cover 525, and a photographing lens appears by sliding the lens cover 525. The digital camera can take a digital photograph by imaging light incident from the taking lens.

(Application example 3)
The electronic device shown in FIG. 27 represents the appearance of a video camera to which the display device 10 according to the present embodiment is applied. This video camera has, for example, a main body 531, a subject photographing lens 532 provided on the front side surface of the main body 531, a start / stop switch 533 during photographing, and a display 534. The display unit 534 is the display device 10 according to the present embodiment.

(Application example 4)
The electronic apparatus shown in FIG. 28 is a notebook personal computer to which the display device 10 according to this embodiment is applied. The notebook personal computer includes, for example, a main body 541, a keyboard 542 for inputting characters and the like, and a display unit 543 that displays an image. The display unit 543 is the display device 10 according to the present embodiment. is there.

(Application example 5)
29 and 30 is a mobile phone to which the display device 10 is applied. FIG. 29 is a front view of the cellular phone when it is opened. FIG. 30 is a front view of the cellular phone folded. For example, the mobile phone includes an upper housing 551 and a lower housing 552 connected by a connecting portion (hinge portion) 553, and includes a display 554, a sub-display 555, a picture light 556, and a camera 557. Yes. The display device 10 is attached to the display 554. Note that the display 554 of the mobile phone may have a function of detecting a touch operation in addition to a function of displaying an image.

(Application example 6)
The electronic device illustrated in FIG. 31 is an information portable terminal that operates as a portable computer, a multifunctional portable phone, a portable computer capable of voice communication, or a portable computer capable of communication, and is sometimes referred to as a so-called smartphone or tablet terminal. . This information portable terminal has a display unit 562 on the surface of a housing 561, for example. The display unit 562 is the display device 10 according to the present embodiment.

(Application example 7)
FIG. 32 is a schematic configuration diagram of a meter unit according to the present embodiment. The electronic device shown in FIG. 32 is a meter unit mounted on a vehicle. A meter unit (electronic device) 570 shown in FIG. 32 includes a plurality of display devices 10 according to the present embodiment described above as a display device 571, such as a fuel gauge, a water temperature gauge, a speedometer, and a tachometer. The plurality of display devices 571 are all covered by a single exterior panel 572.

  Each of the display devices 571 shown in FIG. 32 has a configuration in which a panel 573 as display means and a movement mechanism as analog display means are combined with each other. The movement mechanism has a motor as driving means and a pointer 574 rotated by the motor. As shown in FIG. 32, the display device 571 can display a scale display, a warning display, etc. on the display surface of the panel 573, and the movement mechanism pointer 574 rotates on the display surface side of the panel 573. Is possible.

  In FIG. 32, a plurality of display devices 571 are provided on one exterior panel 572, but the present invention is not limited to this. One display device 571 may be provided in a region surrounded by the exterior panel 572, and a fuel gauge, a water temperature gauge, a speedometer, a tachometer, or the like may be displayed on the display device.

DESCRIPTION OF SYMBOLS 10 Display apparatus 20 Signal processing part 30 Image display panel 40 Image display panel drive part 41 Signal output circuit 42 Scan circuit 48 Pixel 49 Sub pixel 49R 1st sub pixel 49G 2nd sub pixel 49B 3rd sub pixel 49W 4th sub pixel 50 Planar light source device 52 Side light source 54 Light guide plates 56A, 56B, 56C, 56D, 56E, 56F Light source 60 Planar light source device controller

Claims (9)

An image display panel;
A planar light source comprising: a light guide plate that illuminates the image display panel from the back; and a sidelight light source in which a plurality of light sources are arranged at positions opposite to the incident surface with at least one side surface of the light guide plate as an incident surface. When,
A control unit that controls brightness independently for each light source,
The control unit has a light source in which all light sources are of the same level with respect to a lookup table for each light source having information on a light intensity distribution in which incident light incident from the light source is irradiated from the light guide plate onto the plane of the image display panel. A correction lookup table for each light source that suppresses the peak component of the light intensity distribution when the lighting amount is turned on is stored, and the light source lighting of each light source is based on the information for the correction lookup table for each light source and the input signal of the image A display device that controls the amount.   The control unit obtains the correction lookup table for each light source by multiplying the lookup table for each light source by a correction table obtained by taking an inverse number so as to partially include the peak component. The display device described.   3. The control unit according to claim 1, wherein the control unit obtains luminance information in each pixel of the image display panel from the information on the light source lighting amount and the information on the correction look-up table for each light source by interpolation calculation. Display device.   The luminance information in each pixel of the image display panel is subjected to interpolation by processing polynomial interpolation for the light source array direction in which the light sources are arranged, and linear interpolation is processed for the direction orthogonal to the light source array direction. The display device according to claim 1.   The luminance information in each pixel of the image display panel is stored for one side of the center line in the light source array direction, and the other side is luminance information axisymmetric with respect to the center line. Item 4. The display device according to Item 3.   5. The control unit according to claim 2, wherein the control unit performs a correction process on an input signal of the image based on information on luminance in each pixel of the image display panel, and displays the image on the image display panel. Item 1. A display device according to item 1.   The pixels arranged in a matrix on the image display panel include a first subpixel that displays a first color, a second subpixel that displays a second color, a third subpixel that displays a third color, and The display device according to claim 1, further comprising a fourth sub-pixel that displays a fourth color.   An electronic apparatus comprising the display device according to any one of claims 1 to 7. An image display panel;
A planar light source comprising: a light guide plate that illuminates the image display panel from the back; and a sidelight light source in which a plurality of light sources are arranged at positions opposite to the incident surface with at least one side surface of the light guide plate as an incident surface. A method of driving a display device comprising:
An input signal detection step for detecting an input signal of the image;
An image analysis step for analyzing the image;
When all the light sources are turned on at the same light source lighting amount with respect to the look-up table for each light source having information on the light intensity distribution in which the incident light incident from the light source is irradiated from the light guide plate onto the plane of the image display panel And a light source lighting amount calculation step of calculating a light source lighting amount of the light source based on a result of the analysis of the image and a correction look-up table for each light source in which a peak component of the intensity distribution is suppressed.

Images