JP4494765B2 - Image display control apparatus and image display control method - Google Patents

Description

  The present invention controls the transmittance of a liquid crystal display screen that displays an image based on an input image signal, and the amount of light emitted from a backlight that illuminates from the back side of the liquid crystal display screen based on the image signal. The present invention relates to an image display control device and the like that are controlled in accordance with

    2. Description of the Related Art In recent years, a device for adjusting a liquid crystal display screen has been widely used as an image display device in a portable information device such as a so-called notebook personal computer (hereinafter abbreviated as a notebook personal computer). Such an image display device adjusts the transmissivity of the liquid crystal for each pixel of the liquid crystal display screen based on the image data, and illuminates the liquid crystal display screen from the back side with the backlight, whereby the image is displayed on the liquid crystal display screen. Is displayed.

  Since the liquid crystal display screen is thin and compact, it is widely used in portable information devices such as notebook computers. However, the power consumption of the backlight is about 5 W. Taking a notebook computer as an example, the entire notebook computer It has reached about 1/4 to 1/2 of the power consumption. Since portable information devices are usually configured to operate on batteries or the like, how to save power is a big problem.

A conventional image display apparatus will be described with reference to the drawings.
FIG. 20 is a block diagram showing a configuration of a conventional image display apparatus.
The image display device includes a liquid crystal display screen 920 and an image display control device 900 that controls the amount of light emitted from the backlight 921. In the image display control device 900, the data analysis unit 901 obtains a margin that can increase the luminance of the image from the image data input from the image memory 910, and the data adjustment unit 902 based on the obtained margin. The brightness of the image data is adjusted, the image controller 903 generates a drive signal based on the adjusted image data, and the image is displayed on the liquid crystal display screen 920. Further, the light control unit 904 adjusts the amount of light emitted from the backlight 921 according to the margin obtained by the data analysis unit 901.

As a result, the image display control device 900 adjusts the image data so as to increase the transmittance of the liquid crystal display screen 920 as much as possible, and adjusts the light emission amount of the backlight 921 accordingly, thereby adjusting the image data and the back light. An image that is the same as when the light emission amount is not adjusted is displayed to save power (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-65531 (full text)

  However, the image display control apparatus 900 in such an image display apparatus uses many resources such as multipliers in the data analysis unit 901, the data adjustment unit 902, and the like. For this reason, the circuit scale of the image display control device becomes large, and when the image display control device is mounted on a portable information device such as a notebook computer, there is a problem that the portable information device becomes large.

  Accordingly, the present invention has been made in view of such problems, and an object thereof is to provide an image display control device and an image display device having a small circuit scale.

  In order to achieve the above object, an image display control device according to the present invention controls the liquid crystal transmittance of a liquid crystal display screen that displays an image based on an input image signal, and the above-described image signal based on the image signal. An image display control device that controls the amount of light emitted from a backlight that illuminates from the back side of a liquid crystal display screen in accordance with the transmittance of the liquid crystal, the image state detecting means for detecting an image state from the image signal, and Based on the state of the image detected by the image state detection means, the image signal is subjected to certain signal processing to convert the image signal, and the transmittance of the liquid crystal is controlled based on the converted image signal. Image signal converting means to perform, and resources for exclusively assigning arithmetic operation resources for performing arithmetic operations to each of the image state detecting means and the image signal converting means at a predetermined timing And the image state detection means detects the state of the image using the assigned arithmetic operation resource, and the image signal conversion means uses the assigned arithmetic operation resource to output the image signal. It is characterized by converting.

  Thus, the resource control means exclusively assigns arithmetic operation resources to each of the image state detection means and the image signal conversion means at a predetermined timing, and the image state detection means uses the assigned arithmetic operation resources to Since the image signal conversion means converts the image signal using the assigned arithmetic operation resource, the image state detection means and the image signal conversion means can use the arithmetic operation resource jointly. There is no need to provide an arithmetic operation resource for each of the state detection means and the image signal conversion means. Therefore, the arithmetic operation resources of the image display control device can be greatly reduced, and the circuit scale of the image display control device can be reduced.

  The image display control device further converts a color component signal composed of RGB in the image signal into a color information signal including at least a luminance signal and a saturation signal of the color and outputs the color information signal to the image signal conversion means Space conversion means, wherein the resource control means exclusively assigns the arithmetic operation resources to the color space conversion means at a predetermined timing, and the color space conversion means uses the assigned arithmetic operation resources to The color component signal may be converted into the color information signal.

  As a result, in addition to the image state detection means and the image signal conversion means, the color space conversion means jointly uses the arithmetic operation resources described above, so that the arithmetic operation resources of the image display control device can be significantly reduced. The circuit scale of the image display control device can be reduced.

  The image display control device further converts the image signal converted by the image signal conversion means from a color information signal including at least a luminance signal and a saturation signal into a color component signal composed of RGB and outputs the signal. 2 color space conversion means, wherein the resource control means exclusively assigns the arithmetic operation resource to the second color space conversion means at a predetermined timing, and the second color space conversion means is assigned The color information signal may be converted into the color component signal using the arithmetic resource.

  As a result, in addition to the image state detection means, the image signal conversion means, and the color space conversion means, the second color space conversion means jointly uses the above-described arithmetic calculation resources. The circuit scale of the image display control device can be reduced.

The image display control device further includes a clock signal oscillating means for generating a clock signal, and the resource control means counts the passage of the period of the clock signal generated by the clock signal oscillating means to obtain the count number. Accordingly, the arithmetic operation resource may be allocated accordingly.
As a result, the resource control means can allocate arithmetic operation resources at a predetermined timing.

  Further, the image state detection means, the image signal conversion means, the color space conversion means, and the second color space conversion means perform predetermined processing for each pixel in the image signal, and each of the image signal in the image signal The time interval at which the pixels are input may be longer than the period of the clock signal generated by the clock signal oscillating means.

  As a result, the resource control unit allows the image state detection means, the image signal conversion means, the color space conversion means, and the second color space conversion means to perform the respective processes according to the count of the clock signal period elapsed. Arithmetic resources can be allocated as possible.

  Further, the image display control method according to the present invention controls the liquid crystal transmittance of a liquid crystal display screen that displays an image based on an input image signal, and from the back side of the liquid crystal display screen based on the image signal. An image display control method by an image display control device for controlling the amount of light emitted from an illuminating backlight in accordance with the transmittance of the liquid crystal, the image state detecting step for detecting an image state from the image signal, and the image Based on the state of the image detected in the state detection step, the image signal is subjected to certain signal processing to convert the image signal, and the transmittance of the liquid crystal is controlled based on the converted image signal. Image signal conversion step, image state detection means for performing the image state detection step, and arithmetic for performing arithmetic operations on the image signal conversion means for performing the image signal conversion step A resource control step for allocating arithmetic resources exclusively at a predetermined timing, wherein in the image state detection step, the image state detection means detects the state of the image using the assigned arithmetic operation resource, and In the signal conversion step, the image signal conversion means converts the image signal using the assigned arithmetic operation resource.

The present invention is also realized as a program that causes a computer to execute all the steps in the image display control method, a storage medium that stores the program, and an image display device that includes the image display control device and a liquid crystal display screen. can do.
When realized as an image display device, the entire image display device can be downsized.

  The image display control apparatus according to the present invention has the effect that the arithmetic operation resources can be greatly reduced by sharing the arithmetic operation resources, and the circuit scale of the image display control apparatus can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the image display apparatus of the present invention.
The image display device 100 is mounted on a portable information device such as a mobile phone or a notebook computer, and illuminates the liquid crystal display screen 101 that displays an image according to the transmittance of the liquid crystal and the liquid crystal display screen 101 from the back side. And an image display control unit having a function of adjusting the liquid crystal transmittance of the liquid crystal display screen 101 based on the input image signal and adjusting the amount of light emitted from the backlight in accordance with the liquid crystal transmittance 103.

  The image display control unit 103 includes a color increase processing unit 111, a first color space conversion unit 112, an image signal conversion unit 140 including a luminance conversion unit 113 and a saturation conversion unit 114, and a second color space conversion unit 115. A color reduction processing unit 116, an output signal selection unit 117, an image state detection unit 120 including a maximum value detection unit 118 and a total value calculation unit 119, a parameter determination unit 121, a display controller 122, and a data analysis unit 123. A backlight adjustment unit 124, a resource control unit 131, a clock unit 135, a resource unit 132 including a plurality of resource units 610 each including a multiplier table 604 and a multiplier 605, and the like.

  In such an image display control unit 103, one still image (hereinafter referred to as one frame) is based on the image signal acquired by the image state detection unit 120 via the color increase processing unit 111 and the first color space conversion unit 112. ) Detects the state of each image, and the image signal converter 140 converts the luminance signal and saturation signal of the image according to the state of the image. As a result, the image display control unit 103 outputs a control signal for adjusting the transmittance of the liquid crystal of the liquid crystal display screen 101, and adjusts the amount of light emitted from the backlight 102 according to the state of the image. Output a control signal.

  The resource control unit 131 counts the period of the operation clock (clock signal) oscillated from the clock unit 135 at a predetermined time interval, and performs arithmetic operations such as the multiplier table 604 and the multiplier 605 of the resource unit 132 according to the counted number. Arithmetic resources are allocated to each unit such as the luminance conversion unit 113 and the saturation conversion unit 114 in the image display control unit 103 so as to be usable. That is, each unit of the image display control unit 103 uses the arithmetic operation resource of the resource unit 132 jointly. Further, each unit of the image display control unit 103 is operated based on the operation clock oscillated from the clock unit 135.

Here, an image signal input to the image display control unit 103 will be described with reference to FIG.
FIG. 2 is an explanatory diagram showing an image signal of one frame in the image signal input to the image display control unit 103.
As shown in FIG. 2, the image signal of one frame is divided in the horizontal direction and the vertical direction, respectively, and the minimum unit of the divided rectangle is called a pixel. Each pixel has one attribute uniquely represented by R component, G component, and B component which are color components.

  As shown in FIG. 2, if the horizontal direction is the X axis and the vertical direction is the Y axis in the image signal of one frame, and the coordinates of the upper left corner of one frame are (0, 0), the position of each pixel is a coordinate value (x, y). In FIG. 2, the image signal of one frame is divided into M + 1 pixels (M + 1 is a positive integer of 2 or more) in the horizontal direction, and divided into N + 1 pixels (N + 1 is a positive integer of 2 or more) in the vertical direction. Has been.

  The image signal of one frame is obtained by firstly expressing the pixel indicated by the uppermost coordinate (0, 0), coordinate (1, 0), coordinate (2, 0),..., Coordinate (M, 0) in the horizontal direction. Next, in the order of pixels indicated by coordinates (0,1), coordinates (1,1), coordinates (2,1),..., Coordinates (M, 1) in the next stage, from left to right From the upper stage to the lower stage, the image display control unit 103 sequentially inputs and processes them. The following pixels are sequentially processed in the same manner, and finally the lowest coordinate (0, N), coordinate (1, N), coordinate (2, N), ..., coordinate (M, N) in the horizontal direction. ) Are processed in the order of pixels.

  As described above, in the image signal for one frame of the image signal input to the image display control unit 103, the individual pixels representing the attributes of each pixel are serially arranged in the order in which the above-described processing is performed.

Next, each part of the image display control unit 103 will be described in detail.
FIG. 3 is a block diagram illustrating a configuration of the color increase processing unit 111. The color increase processing unit 111 includes a color separation unit 301, an R component color increase unit 302, a G component color increase unit 303, and a B component color increase unit 304. The input image signal is color-coded for each pixel. Are decomposed into component signal R, component signal G, and component signal B, which are RGB components, and the gradation of the component signals of each color is changed and output.

The color separation unit 301 includes a component signal R, a component signal G, and a component, each of which represents the input image signal in 5 bits or 6 bits, according to the parameter value determined by the parameter determination unit 121 shown in FIG. Decompose into signal B.
This parameter value is determined by calculation according to a value determined based on the input from the user by the parameter determination unit 121 from an operation unit (not shown) such as a keyboard and the state of the image for each frame. It is the value.

Here, the instruction by the input from the user corresponds to the color separation unit 301 separating the image signal into component signals represented by 5 bits or 6 bits.
FIG. 4A is a diagram illustrating an image signal for each pixel before the gradation of the component signal of each color is changed. As shown in FIG. 4A, each pixel of coordinates (0, 0), coordinates (1, 0), and coordinates (2, 0) has a bit depth of component signal R of 5 bits and a bit of component signal G. The depth is represented by 6 bits, and the bit depth of the component signal B is represented by 5 bits. The representation in bits in each pixel has a format corresponding to the display on the liquid crystal display screen 101.

  With regard to the component signals of the respective colors obtained by such separation, the above-described R component color increase unit 302, G component color increase unit 303, and B component color increase unit 304 each have a high gradation of each component signal. As described above, the format is changed based on the parameter value determined by the parameter determination unit 121.

FIG. 4B is a diagram illustrating an example of the image signal for each pixel after the gradation of the component signal of each color is changed. As shown in FIG. 4B, each pixel of coordinates (0, 0), coordinates (1, 0), and coordinates (2, 0) has a bit depth of component signal R, component signal G, and component signal B. Is represented by 8 bits.
As an example of changing the color gradation, a description will be given of a state in which the R component color increasing unit 302 has changed from a component signal having a color gradation of 5 bits to a component signal having a color gradation of 8 bits.

FIG. 5 is a schematic diagram illustrating an example when the gradation of the color component is changed.
As shown in FIG. 5, the component signal 311 is a signal whose gradation of the color input to the R component color increase unit 302 is 5 bits, and the component signal 312 is output from the R component color increase unit 302. This is a signal whose color gradation is 8 bits.

At this time, the R component color increasing unit 302 adds the upper 3 bits of the component signal 311 having a color gradation of 5 bits to the lower order of the component signal 311, and the component signal 312 having a color gradation of 8 bits. Has been changed.
Here, an instruction by the user input to the parameter determination unit 121 is that the R component color increase unit 302, the G component color increase unit 303, and the B component color increase unit 304 determine the color gradation in the component signal of each color. This corresponds to changing from 5 bits or 6 bits to 8 bits.
In this way, the color increase processing unit 111 changes the color gradation to a high level, so that it is possible to perform highly accurate processing in the subsequent processing, and the image signal that is finally output becomes high quality. .

FIG. 6 is a block diagram illustrating a configuration of the first color space conversion unit 112.
The first color space conversion unit 112 includes a magnitude relationship detection unit 501, a hue calculation unit 502, a luminance calculation unit 503, a first saturation calculation unit 504, and a second saturation calculation unit 505. The component signal R, component signal G, and component signal B output from the color processing unit 111 are converted into information signals having color information such as hue, luminance, and saturation.

  The magnitude relation detection unit 501 determines which of the component signal R, component signal G, and component signal B output from the color increase processing unit 111 is the maximum value, the intermediate value, and the minimum value. Detect magnitude relationship. When the magnitude relation detection unit 501 detects that the component signal R has the maximum value for the input image signal, the pixel is reddish.

The hue calculation unit 502 determines the signal values of the component signal R, the component signal G, and the component signal B output from the color increase processing unit 111, the magnitude relationship detected by the magnitude relationship detection unit 501, and the parameter determination unit 121. The hue signal H, which is a color information signal, is calculated from the parameter values thus obtained and output to the second color space conversion unit 115.
The luminance calculation unit 503 is determined by the parameter determination unit 121, the signal values of the component signal R, the component signal G, and the component signal B output from the color increase processing unit 111, the magnitude relationship detected by the magnitude relationship detection unit 501, and the magnitude determination unit 121. A luminance signal I, which is a color information signal, is calculated from the obtained parameter values, and is output to the luminance conversion unit 113, the maximum value detection unit 118 of the image state detection unit 120, and the total value calculation unit 119.

The first saturation calculation unit 504 includes the signal values of the component signal R, the component signal G, and the component signal B output from the color increase processing unit 111, the magnitude relationship detected by the magnitude relationship detection unit 501, and the parameter determination unit. A saturation signal S1 that is a color information signal is calculated from the parameter value determined by 121 and output to the saturation conversion unit 114 and the total value calculation unit 119 of the image state detection unit 120.
The second saturation calculation unit 504 includes the signal values of the component signal R, the component signal G, and the component signal B output from the color increase processing unit 111, the magnitude relationship detected by the magnitude relationship detection unit 501, and the parameter determination unit. From the parameter value determined by 121, a saturation signal S2 that is a color information signal is calculated and output to the second color space conversion unit 105.

FIG. 7 is a block diagram illustrating the internal configuration of the hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505.
The hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505 each include a calculation unit 600 as shown in FIG. The calculation unit 600 includes a multiplier determination unit 601, a multiplicand determination unit 602, and a calculation control unit 603. Based on the acquired multiplier data and multiplicand data, and the parameter value determined by the parameter determination unit 121, multiplication is performed. The multiplication result is output to the outside.

On the other hand, the resource unit 132 includes a plurality of resource units 610 including a multiplier table 604 in the form of a memory table and a multiplier 605 that performs multiplication, and these resource units 610 are used in calculations performed by the calculation unit 600.
The multiplier determining unit 601 acquires the multiplier data and the parameter value determined by the parameter determining unit 121, and determines the multiplier with reference to the multiplier table 604 using them as arguments. The multiplicand determining unit 602 acquires multiplicand data and the parameter value determined by the parameter determining unit 121, and determines the multiplicand based on these.

The calculation control unit 603 outputs the multiplier determined by the multiplier determination unit 601 and the multiplicand determined by the multiplicand determination unit 602 to the multiplier 605, and the multiplier 605 multiplies the result of the multiplication processing from the multiplier and the multiplicand. Acquired from 605 and output to the outside.
In the above-described hue calculation unit 502, luminance calculation unit 503, first saturation calculation unit 504, and second saturation calculation unit 505, multiplier data input to the multiplier determination unit 601 is output from the color increase processing unit 111. The multiplicand input as multiplicand data to the multiplicand determining unit 602 is a value based on the magnitude relationship detected by the magnitude relationship detecting unit 501.

The parameter values determined by the parameter determination unit 121 and output to the hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505 vary depending on each unit. The parameter value changes according to the image signal for each frame input to the image display control unit 103.
In each of the hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505, the calculation result output from the calculation control unit 603 of the calculation unit 600 is the hue signal H. , Luminance signal I, saturation signal S1, and saturation signal S2.

  A plurality of resource units 610 including the multiplier table 604 and the multiplier 605 described above are provided in the resource unit 132, and each unit of the image display control unit 103 can be used jointly. Then, the resource control unit 131 assigns the resource unit 610 to the first color space conversion unit 112 at a predetermined timing described later. As a result, the hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505 of the first color space conversion unit 112 have the multiplier table 604 and the multiplier 605 at that timing. Can be used. The number of resource units 610 that the resource control unit 131 allocates to each unit varies depending on the processing performed by each unit.

  That is, the first color space conversion unit 112 according to the present embodiment as a whole causes the resource unit 610 of the resource unit 132 to execute the multiplication shown in the following equation (1), so that the component signals R, G, B Are converted into a hue signal H, a luminance signal I, a saturation signal S1, and a saturation signal S2. Note that Sc shown in Expression (1) is a value determined from the multiplication table 604 based on the component signals R, G, B and the parameter values.

  Next, the image state detection unit 120 that detects the state of the image for each frame in the image signal input to the image display control unit 103 will be described. The image state detection unit 120 includes a maximum value detection unit 118 and a total value calculation unit 119.

  FIG. 8 is a block diagram showing the configuration of the maximum value detection unit 118. The maximum value detecting unit 118 includes a horizontal low-pass filter unit 551, a horizontal maximum value detecting unit 552, a vertical low-pass filter unit 553, a vertical maximum value detecting unit 554, and a maximum value holding unit 555. The maximum luminance of each pixel for each frame is detected and output from the luminance signal I output from the first color space conversion unit 112.

The horizontal low-pass filter unit 551 removes a high-frequency component in the horizontal direction of the luminance signal I output from the first color space conversion unit 112 based on the parameter value output from the parameter determination unit 121.
At this time, the horizontal low-pass filter unit 551 determines the multiplier and the multiplicand based on the luminance signal I output from the first color space conversion unit 112 and the parameter value output from the parameter determination unit 121. The multiplier and multiplicand are output to the resource unit 132, and the multiplication result obtained by the multiplication by the multiplier 605 of the resource unit 132 is obtained from the multiplier 605. Then, the horizontal low-pass filter 551 removes a high frequency component from the luminance signal I serially input from the first color space conversion unit 112 based on the acquired multiplication result and outputs the result.

FIG. 9 is an explanatory diagram for explaining the operation of the horizontal low-pass filter unit 551.
When the change rate of the luminance signal I of each pixel along the horizontal direction in the frame becomes equal to or greater than a predetermined value, the horizontal low-pass filter unit 551 sets the change rate to a constant value, thereby setting the luminance signal I The high frequency component is removed.
That is, as shown in FIG. 9, the horizontal low-pass filter unit 551 acquires the luminance signal I of each pixel from the first color space conversion unit 112, and the change rate ΔIi of the luminance signal I of each pixel in the horizontal direction is X1. If it is less, the change rate ΔIi is converted to the change rate ΔIo by causing the multiplier 605 to execute the calculation of ΔIo = a1 × ΔIi + b1. Here, a1 and b1 are determined based on the parameter values output from the parameter determination unit 121. Further, when the change rate ΔIi is equal to or greater than X1, the horizontal low-pass filter unit 551 causes the multiplier 605 to execute the calculation of ΔIo = a1 × X1 + b1 (= Y1), thereby setting the change rate ΔIi to a constant value. Convert. The horizontal low-pass filter unit 551 outputs a luminance signal I corresponding to the change rate ΔIo to the horizontal maximum value detection unit 552.

The horizontal maximum value detection unit 552 detects the maximum value for each pixel in the horizontal direction for each frame in the luminance signal I output from the horizontal low-pass filter unit 551, and displays the detection result together with the luminance signal I in the vertical direction. The result is output to the low pass filter unit 553.
The vertical low-pass filter unit 553 removes the high-frequency component in the vertical direction of the luminance signal I output from the horizontal maximum value detection unit 552 based on the parameter value output from the parameter determination unit 121.

  At this time, the vertical low-pass filter unit 553 determines the multiplier and the multiplicand based on the luminance signal I output from the horizontal maximum value detection unit 552 and the parameter value output from the parameter determination unit 121. The multiplier and multiplicand are output to the resource unit 132, and the multiplication result obtained by the multiplication by the multiplier 605 of the resource unit 132 is obtained from the multiplier 605. The vertical low-pass filter 553 removes a high frequency component from the luminance signal I serially input from the horizontal maximum value detection unit 552 based on the acquired multiplication result and outputs the result.

The operation of removing the high frequency component of the vertical low-pass filter unit 553 is the same as the operation of the horizontal low-pass filter unit 551 described above. The vertical low-pass filter unit 553 is arranged along the vertical direction in the frame. The multiplier 605 is caused to perform multiplication on the change rate of the luminance signal I of the pixel.
The vertical maximum value detection unit 554 acquires the luminance signal I output from the vertical low-pass filter unit 553, detects the maximum value for each pixel in the vertical direction for each frame, and stores the maximum value in the maximum value holding unit 555. Output.

The maximum value holding unit 555 holds the value output from the vertical direction maximum value detecting unit 554, that is, the maximum value of the luminance signal I of each pixel in each frame, and outputs it to the data analyzing unit 123.
The multiplier 605 used in the maximum value detection unit 118 is provided in the resource unit 132, and each unit of the image display control unit 103 can be used jointly. Then, the resource control unit 131 allocates the resource unit 610 including the multiplier 605 to the maximum value detection unit 118 at a predetermined timing described later. As a result, the maximum value detection unit 118 can use the multiplier 605 at the timing.

FIG. 10 is a block diagram illustrating a configuration of the total value calculation unit 119. The total value calculation unit 119 includes a data limit unit 651, an adder 652, and a total value holding unit 653, and obtains the total value of the saturation signal and the luminance signal of each pixel for each frame. By taking the average of the total values, approximate values of luminance and saturation of the frame are specified for each frame.
The data limit unit 651 limits the luminance signal I and the saturation signal S1 for each pixel output from the first color space conversion unit 112 to valid upper limit values, and outputs them to the adder 652.

  At this time, the data limit unit 651 is effective in the luminance signal I for each pixel from the parameter value output from the parameter determination unit 121 and the luminance signal I for each pixel output from the first color space conversion unit 112. A certain upper limit value is calculated, and an upper limit value that is effective in the saturation signal S1 for each pixel is calculated from the parameter value and the saturation signal S1 for each pixel output from the first color space conversion unit 112. The data limit unit 651, when the luminance signal I and the saturation signal S1 for each pixel output from the first color space conversion unit 112 exceed the calculated upper limit value, the luminance signal I and the saturation signal. S1 is set to the above calculated upper limit value and output to the adder 652.

  When calculating the upper limit value of the luminance signal I, the data limit unit 651 obtains a multiplier and a multiplicand from the luminance signal I and the parameter value for each pixel and outputs them to the resource unit 132, and a multiplier 605 of the resource unit 132. Obtains the multiplication result obtained by multiplying the multiplier and the multiplicand from the multiplier 605 and sets it as the upper limit value. The same applies to the saturation signal S1.

FIG. 11 is an explanatory diagram for explaining an operation of performing upper limit setting on the luminance signal I acquired by the data limit unit 651.
As shown in FIG. 11, the data limit unit 651 acquires the luminance signal I of each pixel from the first color space conversion unit 112, and when the luminance Ii indicated by the acquired luminance signal I is less than X2, , Io = a2 × Ii + b2 is executed by the multiplier 605 to convert the luminance Ii into the luminance Io. Here, a2 and b2 are determined based on the parameter value output from the parameter determination unit 121. Further, when the luminance Ii is equal to or greater than X2, the data limit unit 651 converts the luminance Ii into a constant value by causing the multiplier 605 to execute the calculation of Io = a2 × X2 + b2 (= Y1). Then, the data limit unit 651 outputs a luminance signal I corresponding to the luminance Io to the adder 652.

FIG. 12 is an explanatory diagram for explaining an operation of performing upper limit setting on the saturation signal S1 acquired by the data limit unit 651.
As shown in FIG. 12, the data limit unit 651 acquires the saturation signal S1 of each pixel from the first color space conversion unit 112, and the saturation S1i indicated by the acquired saturation signal S1 is less than X3. In this case, the saturation S1i is converted into the saturation S1o by causing the multiplier 605 to execute the calculation of S1o = a3 × S1i + b3. In addition, when the saturation S1i is equal to or greater than X3 and less than X4, the data limit unit 651 causes the multiplier 605 to execute the calculation of S1o = a3 × X3 + b3 (= Y3) to obtain a constant value for the saturation S1i Convert to Further, when the saturation S1i is equal to or greater than X4, the data limit unit 651 converts the saturation S1i into the saturation S1o by causing the multiplier 605 to perform an operation of S1o = a4 × S1i + b4. Here, a3, a4, b3, and b4 described above are determined based on the parameter values output from the parameter determination unit 121. Then, the data limit unit 651 outputs a saturation signal S1 corresponding to the saturation S1o to the adder 652.

The adder 652 adds the luminance signal I of each pixel output from the data limit unit 651 for each frame, calculates a total value, outputs the total value to the total value holding unit 653, and outputs the saturation signal S1 of each pixel. The sum is calculated for each frame, and the total value is calculated and output to the total value holding unit 653.
The total value holding unit 653 holds the total value of the luminance signal I for each pixel in each frame output from the adder 652 and the total value of the saturation signal S1 in each frame, and outputs them to the data analysis unit 123.

  The multiplier 605 used in the total value calculation unit 119 is provided in the resource unit 132, and each unit of the image display control unit 103 can be used jointly. Then, the resource control unit 131 allocates the resource unit 610 including the multiplier 605 to the total value calculation unit 119 at a predetermined timing described later. Thereby, the total value calculation unit 119 can use the multiplier 605 at the timing.

  The data analysis unit 123 calculates the average value of the luminance signal I at each pixel for each frame from the total value of the luminance signal I at each pixel and the total value of the saturation signal S1 output from the total value calculation unit 119. And the average value of the saturation signal S1, respectively, and the state of the image for each frame is analyzed from each average value and the maximum value of the luminance signal I in each pixel output from the maximum value detection unit 118 for each frame. To do. The data analysis unit 123 outputs a signal indicating a control amount for appropriately controlling the luminance signal and the saturation signal according to the state of the image to the parameter determination unit 121 and appropriately sets the light emission amount of the backlight 102. A signal indicating a control amount for control is output to the backlight adjustment unit 124.

The backlight adjustment unit 124 calculates an adjustment value for adjusting the light emission amount of the backlight 102 according to the signal (control amount) output from the data analysis unit 123 and outputs the adjustment value to the backlight 102.
Next, the image signal converter 140 will be described. The image signal conversion unit 140 includes a luminance conversion unit 113 and a saturation conversion unit 114, and converts the luminance signal I and the saturation signal S1 of each pixel based on the state of the image detected by the image state detection unit 120.

The luminance conversion unit 113 performs an arithmetic process on the luminance signal I output from the first color space conversion unit 112 based on the parameter value determined by the parameter determination unit 121, thereby converting the luminance signal I into the luminance signal I ′. And output to the second color space conversion unit 115.
That is, the luminance conversion unit 113 includes a calculation unit 600 shown in FIG. In this luminance conversion unit 113, both the multiplier data input to the multiplier determination unit 601 of the calculation unit 600 and the multiplicand data input to the multiplicand determination unit 602 are for each pixel output from the first color space conversion unit 112. Luminance signal I.

Further, as described above, the data analysis unit 123 sets a parameter indicating a signal indicating a control amount for appropriately controlling the luminance signal and the saturation signal according to the state of the image for each frame detected by the image state detection unit 120. The data is output to the determination unit 121. The parameter determination unit 121 determines a parameter value for converting the luminance signal I based on the control amount.
The calculation unit 600 included in the luminance conversion unit 113 refers to the multiplier table 604 of the resource unit 132 on the basis of the luminance signal I that is input multiplier data and the parameter value determined by the parameter determination unit 121. At the same time, the multiplicand is determined based on the luminance signal I that is input multiplicand data and the parameter value determined by the parameter determination unit 121. Then, the calculation control unit 603 of the calculation unit 600 outputs the multiplier and the multiplicand to the multiplier 605 of the resource unit 132, obtains the result of multiplication by the multiplier 605 from the multiplier 605, and uses it as the converted luminance signal I ′. The data is output to the second color space conversion unit 115.

That is, the luminance conversion unit 113 multiplies the multiplier 605 by (multiplier specified from the multiplier table 604 based on the luminance signal I and the parameter value) × (multiplicand specified based on the luminance signal I and the parameter value). By executing, the luminance signal I is converted into the luminance signal I ′.
Thus, the luminance conversion unit 113 converts the luminance signal I according to the state of the image for each frame. For example, if the image for each frame is an image having a low luminance as a whole, the luminance conversion unit 113 converts the luminance signal I so as to increase the luminance, assuming that there is room for increasing the luminance. At this time, the backlight adjustment unit 124 reduces the amount of light emitted from the backlight 102 in accordance with the increased luminance by the control signal from the data analysis unit 123. As a result, it is possible to save power by reducing the amount of light emitted from the backlight without changing the state of the actually visible image.

  A resource unit 610 including a multiplier table 604 and a multiplier 605 used by the luminance conversion unit 113 is provided in the resource unit 132, and each unit of the image display control unit 103 can be used jointly. Then, the resource control unit 131 allocates the resource unit 610 to the luminance conversion unit 113 at a predetermined timing described later. Thereby, the luminance conversion unit 113 can use the multiplier table 604 and the multiplier 605 at the timing.

  Here, the luminance conversion unit 113 converts the luminance signal I based on the state of the image for each frame detected by the image state detection unit 120, but the detection is performed based on the state of the image detected in the previous frame. The luminance signal I in the next frame of the obtained image is converted. Since the image signal is inputted for 10 to 15 frames per second, there is almost no difference in the image signal between one frame. Therefore, there is no visual problem even if the luminance signal I is converted in the next frame based on the state of the image detected in the previous frame.

  Note that the luminance signal I in the same frame may be converted based on the state of the detected image (frame). In this case, an image signal of one frame is stored in a memory or the like, the state of the frame is detected, and the luminance signal I of the frame is converted based on the detected result.

  Next, the saturation conversion unit 114 will be described. The saturation conversion unit 114 performs an arithmetic process on the saturation signal S1 output from the first color space conversion unit 112 based on the parameter value determined by the parameter determination unit 121, thereby converting the saturation signal S1 into saturation. The signal is converted into a signal S1 ′ and output to the second color space conversion unit 115.

  That is, the saturation conversion unit 114 includes a calculation unit 600 shown in FIG. In the saturation conversion unit 114, both the multiplier data input to the multiplier determination unit 601 of the calculation unit 600 and the multiplicand data input to the multiplicand determination unit 602 are pixels output from the first color space conversion unit 112. This is based on each saturation signal S1.

  Further, as described above, the data analysis unit 123 outputs a signal indicating a control amount for appropriately controlling the luminance signal and the saturation signal according to the state of the image for each frame detected by the image state detection unit 120 as a parameter determination unit. It outputs to 121. The parameter determination unit 121 determines a parameter value for converting the saturation signal S1 based on the control amount.

  The calculation unit 600 included in the saturation conversion unit 114 refers to the multiplier table 604 of the resource unit 132 based on the saturation signal S1 that is input multiplier data and the parameter value determined by the parameter determination unit 121. In addition to determining the multiplier, the multiplicand is determined based on the saturation signal S1, which is input multiplicand data, and the parameter value determined by the parameter determination unit 121. Then, the calculation control unit 603 of the calculation unit 600 outputs the multiplier and multiplicand to the multiplier 605 of the resource unit 132, acquires the result of multiplication by the multiplier 605 from the multiplier 605, and converts the converted saturation signal S1 ′. Is output to the second color space conversion unit 115.

That is, the saturation conversion unit 114 multiplies multiplication by (multiplier specified from the multiplier table 604 based on the saturation signal S1 and the parameter value) × (multiplicand specified based on the saturation signal S1 and the parameter value). The saturation signal S1 is converted into a saturation signal S1 ′ by causing the controller 605 to execute the saturation signal S1.
Thus, the saturation conversion unit 114 converts the saturation signal S1 according to the state of the image for each frame. For example, if the image for each frame is an image with low saturation as a whole, the saturation conversion unit 114 determines that there is room for increasing the saturation as a whole, and the saturation conversion unit 114 increases the saturation so as to increase the saturation. Convert. At this time, the backlight adjustment unit 124 reduces the amount of light emitted from the backlight 102 in accordance with the increased saturation by the control signal from the data analysis unit 123. As a result, it is possible to save power by reducing the amount of light emitted from the backlight without changing the state of the actually visible image.

  A resource unit 610 including a multiplier table 604 and a multiplier 605 used by the saturation conversion unit 114 is provided in the resource unit 132, and each unit of the image display control unit 103 can be used jointly. Then, the resource control unit 131 allocates the resource unit 610 to the saturation conversion unit 114 at a predetermined timing described later. Thereby, the saturation conversion unit 114 can use the multiplier table 604 and the multiplier 605 at the timing.

  Here, the saturation conversion unit 114 converts the saturation signal S1 based on the state of the image for each frame detected by the image state detection unit 120, but based on the state of the image detected in the previous frame, The saturation signal S1 in the next frame of the detected image is converted. Since the image signal is inputted for 10 to 15 frames per second, there is almost no difference in the image signal between one frame. For this reason, there is no visual problem even if the saturation signal S1 in the next frame is converted based on the state of the image detected in the previous frame.

  Note that the saturation signal S1 in the same frame may be converted based on the state of the detected image (frame). In this case, an image signal of one frame is stored in a memory or the like, the state of the frame is detected, and the saturation signal S1 of the frame is converted based on the detected result.

Next, the second color space conversion unit 115 will be described.
FIG. 13 is a block diagram illustrating an example of an internal configuration of the second color space conversion unit 115. The second color space conversion unit 115 includes a maximum value calculation unit 701, an intermediate value calculation unit 702, a minimum value calculation unit 703, and a data selection unit 704.
The second color space conversion unit 115 has a luminance signal I ′ output from the luminance conversion unit 113, a saturation signal S1 ′ output from the saturation conversion unit 114, and a first color space conversion unit 112. Based on the output hue signal H and saturation signal S2 and the parameter value output from the parameter determination unit 121, the component signal R ′, the component signal G ′, and the component signal B ′, which are component signals of colors, And output to the color reduction processing unit 116.

Here, the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703 each include a calculation unit 600 shown in FIG.
In each of the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703, the multiplier data input to the multiplier determination unit 601 of the calculation unit 600 and the multiplicand data input to the multiplicand determination unit 602 are Each of the values is based on any combination of the luminance signal I ′, the saturation signal S1 ′, and the saturation signal S2 described above.

  In each of the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703, the calculation unit 600 includes a value based on the above-described combination that is input multiplier data, and a parameter value determined by the parameter determination unit 121. Based on the above, the multiplier is determined with reference to the multiplier table 604 of the resource unit 132, and based on the value based on the above-described combination that is the multiplicand data to be input and the parameter value determined by the parameter determination unit 121 Determine the multiplicand.

  In each of the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703, the calculation control unit 603 of the calculation unit 600 outputs the determined multiplier and multiplicand to the multiplier 605 of the resource unit 132, The multiplier 605 obtains the result of multiplication from the multiplier 605 and outputs the maximum value, the intermediate value, and the minimum value, which are the respective calculation results, to the data selection unit 704.

  That is, each of the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703 includes a multiplier from a value based on the combination of the luminance signal I ′, the saturation signal S1 ′, and the saturation signal S2 and the parameter value. Multiplier 605 is multiplied by a multiplier specified with reference to table 604) × (a multiplicand specified from a value based on a combination of luminance signal I ′, saturation signal S1 ′ and saturation signal S2 and a parameter value). Let it run.

  The maximum value calculation unit 701 outputs the maximum value among the multiplication results obtained by changing the combination, and the intermediate value calculation unit 702 outputs the intermediate value among the multiplication results obtained by changing the combination. The minimum value calculation unit 703 outputs the minimum value among the multiplication results obtained by changing the above combinations. The parameter values described above are different values in the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703.

The data selection unit 704 is a calculation result output from the maximum value calculation unit 701, the intermediate value calculation unit 702, and the minimum value calculation unit 703 based on the hue signal H output from the first color space conversion unit 112. One of the maximum value, the intermediate value, and the minimum value is selected and output to the color reduction processing unit 116 as a component signal R ′, a component signal G ′, and a component signal B ′ indicating the RGB components of the color.
A resource unit 610 including a multiplier table 604 and a multiplier 605 used by the second color space conversion unit 115 is provided in the resource unit 132, and each unit of the image display control unit 103 can be used jointly. Then, the resource control unit 131 allocates the resource unit 610 to the second color space conversion unit 115 at a predetermined timing described later. Thereby, the second color space conversion unit 115 can use the multiplier table 604 and the multiplier 605 at the timing.

Next, the color reduction processing unit 116 will be described.
FIG. 14 is a block diagram illustrating a configuration of the color reduction processing unit 116. The color reduction processing unit 116 includes an R component color reduction unit 801, a G component color reduction unit 802, and a B component color reduction unit 803. The color reduction processing unit 116 acquires the color component signal R ′, the component signal G ′, and the component signal B ′ output from the second color space conversion unit 115, and performs color gradation in each component signal. And output to the output signal selection unit 117. For example, when each component signal is an 8-bit signal, it is changed to a 5-bit signal that can be displayed on the liquid crystal display screen 101 by performing dither processing.

  The R component color reduction unit 801, the G component color reduction unit 802, and the B component color reduction unit 803 are respectively color component signals output from the second color space conversion unit 105 according to the parameter values determined by the parameter determination unit 121. The color tone of R ′, component signal G ′, and component signal B ′ is changed, and an image signal composed of component signal R ″, component signal G ″, and component signal B ″ is output to output signal selection section 117. At this time, the parameter determination unit 121 sets a parameter value according to the input from the user, and the parameter determination unit 121 can change the parameter value according to the state of the image for each frame.

FIG. 15 is a diagram illustrating an example of a state in which the color gradation is changed for the color component signal output from the second color space conversion unit 115.
In this example, the R component color reduction unit 801, the G component color reduction unit 802, and the B component color reduction unit 803 perform effective color reduction processing (for example, dither processing) on the component signal 851 whose color gradation is 8 bits. As a result, the component signal 851 is changed to a component signal 852 having a color gradation of 5 bits.

The output signal selection unit 117 includes an image signal input to the image display control unit 103 and an image signal output from the color reduction processing unit 116 based on the parameter value determined by the parameter determination unit 121 according to a user instruction. One of the image signals is selected for each frame, and the selected image signal is output to the display controller 122.
The display controller 122 calculates the transmittance of the liquid crystal on the liquid crystal display screen 101 based on the image signal selected by the output signal selection unit 117 and outputs it to the liquid crystal display screen 101.

Here, the resource control unit 131 in the present embodiment will be described.
FIG. 16 is a time chart illustrating the operation clock input to the resource control unit 131, the input timing of the image signal, and the distribution state in which the resource units 610 are allocated to each unit.
In FIG. 16, the uppermost stage shows the operation clock input to the resource control unit 131, and the next stage shows the input timing of the image signal input to the image display control apparatus 103 in pixel units. The lower part shows the distribution state of the resource units 610 according to the count number of the operation clock period input to the resource control unit 131.

As shown in FIG. 16, time t1 and time t2 are input times of image signals in units of pixels, and image signals are input every 8 cycles of the operation clock in units of pixels.
When an image signal is input in pixel units to the image display control unit 103 (time t1), the resource control unit 131 starts counting the period of the operation clock input from the clock unit 135. The resource control unit 131 assigns the resource unit 610 of the resource unit 132 to the first color space conversion unit 112 when the count number is 1, and replaces the first color space conversion unit 112 when the count number is 2. When the resource unit 610 is assigned to the luminance conversion unit 113 and the count number is 3, the resource unit 610 is assigned to the saturation conversion unit 114 instead of the luminance conversion unit 113 and the count number is 4. Assigns a resource unit 610 to the second color space conversion unit 115 instead of the saturation conversion unit 114, and when the count number is 5, the maximum value detection unit instead of the second color space conversion unit 115 When a resource unit 610 is assigned to 118 and the count number is 6, a total value calculation unit 119 is used instead of the maximum value detection unit 118 Assign resource units 610 for.

  That is, at the allocated time, each unit such as the luminance conversion unit 113 can use resources such as the multiplier 605 in the resource unit 610. At this time, the resource control unit 131 is performed by the first color space conversion unit 112, the luminance conversion unit 113, the saturation conversion unit 114, the second color space conversion unit 115, the maximum value detection unit 118, and the total value calculation unit 119. The number of resource units 610 to be allocated is changed according to processing. For example, when the processing performed by the first color space conversion unit 112 requires two resource units 610 and the processing performed by the luminance conversion unit 113 requires three resource units 610, the resource control unit 131 counts The two resource units 610 are allocated to the first color space conversion unit 112 when the number 1 and then the allocation to the first color space conversion unit 112 is prohibited when the count number is 2, and the luminance conversion unit 113 is The two resource units 610 and one other resource unit 610 are allocated.

  Further, the resource unit 610 is sequentially provided for each of the hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505 provided in the first color space conversion unit 112. Assigned. The resource control unit 131 assigns resource units 610 to the hue calculation unit 502, the luminance calculation unit 503, the first saturation calculation unit 504, and the second saturation calculation unit 505 of the first color space conversion unit 112, respectively. Each unit to which the resource unit 610 is allocated may execute processing simultaneously using the resource unit 610.

Next, an operation in which the resource control unit 131 assigns the resource unit 610 of the resource unit 132 will be described.
FIG. 17 is a flowchart showing the operation of the resource control unit 131.
First, the resource control unit 131 determines whether or not a pixel signal indicating one pixel of the image signals is input to the image display control unit 103 (step S1), and determines that a pixel signal is input (step S1). Y), the count number C of the built-in counter is reset (step S2). In the example shown in FIG. 17, it is assumed that the pixel signal is input every six cycles of the operation clock.

Next, the resource control unit 131 determines whether or not the cycle of the operation clock input from the clock unit 135 has been completed (step S3). If it is determined that the cycle has been completed (Y in step S3), the counter counts up Is started (step S4).
The resource control unit 131 determines whether or not the count number C of the counter is 1 (step S5). If the count number C is 1 (Y in step S5), the first color space conversion unit 112 is determined. The resource unit 610 of the resource unit 132 is assigned to (step S6), and it is determined again whether or not the cycle of the operation clock has been completed (step S3).

  When the resource control unit 131 determines that the count number C of the counter is not 1 (N in step S5), the resource control unit 131 determines whether the count number C is 2 (step S7). Is determined to be 2, the resource unit 610 of the resource unit 132 is allocated to the luminance conversion unit 113 instead of the first color space conversion unit 112 (step S8), and the cycle of the operation clock has been cycled again. It is determined whether or not (step S3).

  Further, when the resource control unit 131 determines that the count number C of the counter is not 2 (N in Step S7), the resource control unit 131 determines whether or not the count number C of the counter is 3 (Step S9). If it is determined that C is 3, the resource unit 610 of the resource unit 132 is allocated to the saturation conversion unit 114 instead of the luminance conversion unit 113 (step S10), and whether or not the cycle of the operation clock has been completed once again. Is determined (step S3).

  Further, when the resource control unit 131 determines that the count number C of the counter is not 3 (N in Step S9), the resource control unit 131 determines whether or not the count number C of the counter is 4 (Step S11). If it is determined that C is 4, the resource unit 610 of the resource unit 132 is allocated to the second color space conversion unit 115 instead of the saturation conversion unit 114 (step S12), and the cycle of the operation clock is cycled again. It is determined whether or not it has been done (step S3).

  Further, when the resource control unit 131 determines that the count number C of the counter is not 4 (N in step S11), the resource control unit 131 determines whether or not the count number C of the counter is 5 (step S13). When it is determined that C is 5, the resource unit 610 of the resource unit 132 is allocated to the maximum value detection unit 118 instead of the second color space conversion unit 115 (step S14), and the cycle of the operation clock is cycled again. It is determined whether or not it has been done (step S3).

Further, when the resource control unit 131 determines that the count number C of the counter is not 5 (N in step S13), the resource unit 610 of the resource unit 132 is compared with the total value calculation unit 119 instead of the maximum value detection unit 118. Is assigned (step S15), and it is determined again whether a pixel signal is input (step S1).
According to the image display apparatus 100 in the present embodiment, the resource control unit 131 determines the first color space conversion unit 112, the luminance conversion unit 113, the saturation conversion unit 114, the maximum value according to the count number of the period of the operation clock. A resource unit 610 including a multiplier table 604 and a multiplier 605 is sequentially assigned to each unit such as the detection unit 118, the total value calculation unit 119, and the second color space conversion unit 115, and each unit such as the luminance conversion unit 113 performs processing. Since the resource unit 610 assigned at the time of performing is used, each unit such as the luminance conversion unit 113 can use the same resource unit 610 in common. Therefore, the resource unit 610 of the image display control unit 103 can be significantly reduced, and the circuit scale of the image display apparatus 100 can be reduced.

  When the image display device 100 according to the present embodiment is mounted on a portable terminal such as a cellular phone, the screen size of the liquid crystal display screen 101 is small, so that the pixel of the image signal input to the image display control unit 103 and the pixel The interval is very long compared to the period of the operation clock of the mobile terminal. In addition, since the transfer rate of the memory storing the image signal input to the image display control unit 103 to the image display control unit 103 is also slower than the cycle of the operation clock of the portable terminal, the input to the image display control unit 103 is performed. The interval between pixels of the image signal to be processed is generally very long.

  In this way, when the interval between the pixels of the image signal input to the image display control unit 103 is long, the resource unit 610 is switched to and assigned to each unit at a timing according to the count number of the operation clock, etc. A small number of resource units 610 can be used in common by each unit. Thereby, the redundant resource unit 610 can be omitted, and the circuit scale of a device such as a portable terminal in which the image display control unit 103 is mounted can be reduced. The present embodiment is extremely realistic and very effective for mounting on a mobile terminal represented by a mobile phone.

On the other hand, when the transfer rate of the memory storing the image signal input to the image display control unit 103 is high and the interval between the pixels of the image signal input to the image display control unit 103 is short The resource control unit 131 may increase the number of resource units 610 allocated to each unit such as the luminance conversion unit 113 and the maximum value detection unit 118.
That is, when the transfer rate is high, the resource control unit 131 assigns the resource unit 610 to each unit such as the first color space conversion unit 112 and the luminance conversion unit 113 at the same time, and the resource unit 610 assigned to each unit. Multiplication by is executed in parallel.

FIG. 18 is an operation explanatory diagram illustrating an example of an operation in which the resource control unit 131 allocates three resource units 610 in parallel. Here, in order to distinguish the three resource units 610, they are represented as resource units 610a, 610b, and 610c, respectively.
For example, as illustrated in FIG. 18, the resource control unit 131 allocates the resource unit 610 a to the first color space conversion unit 112 and allocates the resource unit 610 b to the luminance conversion unit 113 between time t10 and t11. 610 c is assigned to the saturation conversion unit 114. Accordingly, the first color space conversion unit 112, the luminance conversion unit 113, and the saturation conversion unit 114 cause the three resource units 610a, 610b, and 610c to perform multiplication in parallel.

  Next, between time t11 and t12, the resource control unit 131 reassigns the resource unit 610a from the first color space conversion unit 112 to the second color space conversion unit 115, and sets the resource unit 610b from the luminance conversion unit 113 to the maximum value. The resource unit 610c is reassigned from the saturation conversion unit 114 to the total value calculation unit 119. As a result, the second color space conversion unit 115, the maximum value detection unit 118, and the total value calculation unit 119 cause the three resource units 610a, 610b, and 610c to perform multiplication in parallel.

After time t12, the allocation of the three resource units 610a, 610b, and 610c performed at time t10 to t12 is repeatedly executed.
The image display apparatus 100 according to the present invention has been described above using the present embodiment, but the present invention is not limited to these.
For example, in the present embodiment, the image display apparatus 100 includes only one set of the liquid crystal display screen 101 and the backlight 102. However, a plurality of sets of the liquid crystal display screen 101 and the backlight 102 may be provided. You may vary the size.

  For example, when two sets of liquid crystal display screens 101 and backlights 102 having different sizes are provided in the image display device 100, the parameter determination unit 121 determines which one of the liquid crystal display screens 101 is based on a user operation. Select whether to display an image. Then, each unit provided in the image display control unit 103 executes processing according to the size of the selected liquid crystal display screen 101 to display an image on the liquid crystal display screen 101.

Here, when the two sets of the liquid crystal display screen 101 and the backlight 102 having different sizes are used as described above, the resource control unit 131 sets the first color space conversion unit 112 according to the size. And the number of resource units 610 allocated to each unit such as the luminance conversion unit 113 are varied.
That is, when an image is displayed on the larger liquid crystal display screen 101, the resource control unit 131 assigns a large number of resource units 610 to each unit such as the first color space conversion unit 112, and the smaller liquid crystal display screen 101. When an image is displayed, a small number of resource units 610 are allocated because the input interval of pixels included in the image signal becomes long.

FIG. 19 is an application example diagram showing an example in which the image display device 100 including two liquid crystal display screens having different sizes is applied to a mobile phone.
The cellular phone device 500 has an operation unit 520 provided with operation buttons for inputting a telephone number, and two liquid crystal display screens 101a and 101b, and is rotatably attached to one side of the operation unit 520. The display unit 510 is provided. A larger liquid crystal display screen 101 a is attached to the front surface side of the display unit 510, and a smaller liquid crystal display screen 101 b is attached to the back surface side of the display unit 510.

In such a cellular phone device 500, when the display unit 510 is rotated, the display unit 510 is superimposed on the operation unit 520 and the liquid crystal display screen 101a and the operation buttons are stored, and the liquid crystal display screen 101a. The mode is changed to a call state in which the operation buttons are exposed and a call can be made.
That is, when the cellular phone device 500 on which the image display device 100 according to the present embodiment is mounted is in a call state by a user operation, the larger liquid crystal display screen 101a is selected by the parameter determination unit 121, and the liquid crystal display screen 101a is selected. Display an image on.

  Here, when the user places the cellular phone device 500 in a folded state, the smaller liquid crystal display screen 101b is selected by the parameter determination unit 121, and the cellular phone device 500 switches from the liquid crystal display screen 101a to the liquid crystal display screen 101b to display an image. Is displayed. At this time, since the size of the liquid crystal display screen is reduced, the resource control unit 131 stops the operation of the unnecessary resource unit 610 among the plurality of resource units 610 allocated in the call state.

Thus, power saving can be achieved by stopping the operation of the resource unit 610 according to the state of the mobile phone device 500.
Further, when the cellular phone device 500 is folded, the resource unit 610 may be used for multiplication processing for other purposes instead of stopping the operation of the resource unit 610 that is no longer necessary for image display. Thereby, the resource unit 610 can be used effectively, and the mobile phone device 500 as a whole can be downsized.

In the above description, an image is displayed on either one of the liquid crystal display screens 101a and 101b depending on the state of the mobile phone 500. However, when in a call state, the image is displayed on each of the two liquid crystal display screens 101a and 101b. May be displayed and an image may be displayed only on the liquid crystal display screen 101b in the folded state.
Further, although a plurality of resource units 610 are provided in the present embodiment, only one resource unit 610 may be provided. In this case, the resource unit 610 is assigned to each unit in the image display control unit 103 in order and used.

  The image display control device according to the present invention can greatly reduce resources and reduce the circuit scale, and can be applied to mobile terminals such as mobile phones and laptop computers.

It is a block diagram which shows the structure of the image display apparatus in embodiment of this invention. It is explanatory drawing explaining an image signal same as the above. It is a block diagram which shows the structure of a color increase process part same as the above. (A) is explanatory drawing explaining the component signal of the color for every pixel input into an image display apparatus same as the above, (b) is the color component signal for every pixel after a gradation was changed. It is explanatory drawing demonstrated. It is explanatory drawing explaining the change of the gradation of a color by the color increase process part same as the above. It is a block diagram which shows the structure of the 1st color space conversion part same as the above. It is a block diagram which shows the structure of the calculation part and resource part which are used for each part of an image display apparatus same as the above. It is a block diagram which shows the structure of the maximum value detection part same as the above. It is explanatory drawing for demonstrating operation | movement of a horizontal direction low-pass filter part same as the above. It is a block diagram which shows the structure of a total value calculation part same as the above. It is explanatory drawing for demonstrating the operation | movement with respect to the luminance signal of a data limit part same as the above. It is explanatory drawing for demonstrating the operation | movement with respect to the saturation signal of a data limit part same as the above. It is a block diagram which shows the structure of the 2nd color space conversion part same as the above. It is a block diagram which shows the structure of a color reduction process part same as the above. It is explanatory drawing explaining the change of the gradation of a color by the color reduction process part same as the above. It is distribution state explanatory drawing which shows the distribution state of the resource by the input timing of the operation clock same as the above, and the count number of the operation clock. It is a flowchart which shows operation | movement of the resource control part same as the above. It is a flowchart which shows other operation | movement of a resource control part same as the above. It is an application example figure which shows an example which applied this Embodiment to the mobile telephone device. It is a block diagram which shows the structure of the conventional image display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image display apparatus 101 Liquid crystal display screen 102 Backlight 103 Image display control part 111 Color increase process part 112 1st color space conversion part 113 Luminance conversion part 114 Saturation conversion part 115 2nd color space conversion part 116 Subtractive color process part 117 Output Signal selection unit 118 Maximum value detection unit 119 Total value calculation unit 120 Image state detection unit 121 Parameter determination unit 122 Display controller 123 Data analysis unit 124 Backlight adjustment unit 131 Resource control unit 132 Resource unit 135 Clock unit 604 Multiplier table 605 Multiplier 610 Resource unit

Claims (13)

Controls the liquid crystal transmittance of a liquid crystal display screen that displays an image based on an input image signal, and transmits the amount of light emitted from a backlight that illuminates from the back side of the liquid crystal display screen based on the image signal. An image display control device that controls the rate according to the rate,
Image state detecting means for detecting an image state from the image signal;
Based on the state of the image detected by the image state detection means, the image signal is subjected to a certain signal processing to convert the image signal, and the transmittance of the liquid crystal is determined based on the converted image signal. Image signal conversion means for controlling;
Resource control means for exclusively assigning arithmetic operation resources for performing arithmetic operations to each of the image state detection means and the image signal conversion means at a predetermined timing;
The image state detection means detects the state of the image using the assigned arithmetic operation resource,
The image display control device, wherein the image signal conversion means converts the image signal using the assigned arithmetic operation resource. The image display control device further converts a color component signal composed of RGB in the image signal into a color information signal including at least a color luminance signal and a saturation signal, and outputs the color information signal to the image signal conversion means. With means,
The resource control means exclusively allocates the arithmetic resource at a predetermined timing to the color space conversion means,
The image display control apparatus according to claim 1, wherein the color space conversion unit converts the color component signal into the color information signal using the assigned arithmetic operation resource. The image display control device further converts the image signal converted by the image signal conversion means from a color information signal including at least a luminance signal and a saturation signal into a color component signal of RGB and outputs the second component signal. Color space conversion means,
The resource control means exclusively allocates the arithmetic resource to the second color space conversion means at a predetermined timing;
The image display control apparatus according to claim 2, wherein the second color space conversion unit converts the color information signal into the color component signal using the allocated arithmetic operation resource. The image signal conversion unit includes a luminance conversion unit that converts a luminance signal output from the color space conversion unit based on the image state detected by the image state detection unit, and an image detected by the image state detection unit. A saturation conversion unit that converts the saturation signal output by the color space conversion unit based on the state;
The resource control means exclusively allocates the arithmetic operation resource to the luminance conversion unit at a predetermined timing, and exclusively allocates the arithmetic operation resource to the saturation conversion unit at a predetermined timing,
The luminance conversion unit converts the luminance signal using the assigned arithmetic resource,
The image display control device according to claim 3, wherein the saturation conversion unit converts the saturation signal using the assigned arithmetic operation resource. The image display control device further includes clock signal oscillation means for generating a clock signal,
The image display control apparatus according to claim 4, wherein the resource control unit counts a lapse of a cycle of the clock signal generated by the clock signal oscillation unit and allocates the arithmetic operation resource according to the count number. The image state detection means, the image signal conversion means, the color space conversion means, and the second color space conversion means perform predetermined processing for each pixel in the image signal,
The image display control apparatus according to claim 5, wherein a time interval at which the pixels are input in the image signal is longer than a cycle of the clock signal generated by the clock signal oscillating means. The image display control device includes a plurality of resource units including the arithmetic operation resources,
The image display control apparatus according to claim 6, wherein the resource control unit allocates, to the allocation target, a number of the resource units corresponding to processing performed by the allocation target to which the arithmetic operation resource is allocated. The image display control apparatus according to claim 7, wherein the arithmetic operation unit is a multiplier. The image state detection means detects the state of the image for each frame from the image signal,
9. The image display according to claim 8, wherein the image signal conversion unit converts an image signal of a frame input after that based on the state of one frame image detected by the image state detection unit. Control device. Controls the liquid crystal transmittance of a liquid crystal display screen that displays an image based on an input image signal, and transmits the amount of light emitted from a backlight that illuminates from the back side of the liquid crystal display screen based on the image signal. An image display control method by an image display control device that controls according to a rate,
An image state detection step of detecting an image state from the image signal;
Based on the state of the image detected in the image state detection step, the image signal is converted by performing certain signal processing on the image signal, and the transmittance of the liquid crystal is determined based on the converted image signal. An image signal conversion step to be controlled;
An image state detection unit that performs the image state detection step, and a resource control step that exclusively allocates arithmetic operation resources for performing arithmetic operations to the image signal conversion unit that performs the image signal conversion step at a predetermined timing,
In the image state detection step, the image state detection means detects the state of the image using the assigned arithmetic resource,
In the image signal conversion step, the image signal conversion means converts the image signal using the assigned arithmetic operation resource. 11. The image display control method according to claim 10, wherein in the resource control step, the elapsed time of the clock signal output from the clock signal oscillator is counted, and the arithmetic operation resource is allocated according to the count number. Controls the liquid crystal transmittance of a liquid crystal display screen that displays an image based on an input image signal, and transmits the amount of light emitted from a backlight that illuminates from the back side of the liquid crystal display screen based on the image signal. A program executed by an image display control device that controls the rate according to the rate,
An image state detection step of detecting an image state from the image signal;
Based on the state of the image detected in the image state detection step, the image signal is converted by performing certain signal processing on the image signal, and the transmittance of the liquid crystal is determined based on the converted image signal. An image signal conversion step to be controlled;
An image state detection unit that performs the image state detection step, and a resource control step that exclusively allocates arithmetic operation resources for performing arithmetic operations to the image signal conversion unit that performs the image signal conversion step at a predetermined timing,
In the image state detection step, the image state detection means detects the state of the image using the assigned arithmetic resource,
In the image signal conversion step, the image signal conversion means converts the image signal using the assigned arithmetic operation resource. A liquid crystal display screen that displays an image, a backlight that illuminates from the back side of the liquid crystal display screen, and controls the liquid crystal transmittance of the liquid crystal display screen based on the input image signal, and based on the image signal An image display device comprising an image display control device that controls the amount of light emitted from a backlight in accordance with the transmittance of the liquid crystal,
The image display control device includes:
Image state detecting means for detecting an image state from the image signal;
Based on the state of the image detected by the image state detection means, the image signal is converted by performing certain signal processing on the image signal, and the transmittance of the liquid crystal is determined based on the converted image signal. Image signal conversion means for controlling;
Resource control means for exclusively assigning arithmetic operation resources for performing arithmetic operations to each of the image state detection means and the image signal conversion means at a predetermined timing;
The image state detection means detects the state of the image using the assigned arithmetic operation resource,
The image display device, wherein the image signal conversion means converts the image signal using the assigned arithmetic operation resource.

Images