WO2012023326A1 - Contrôleur de rétroéclairage et dispositif d'affichage d'image - Google Patents

Contrôleur de rétroéclairage et dispositif d'affichage d'image Download PDF

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Publication number
WO2012023326A1
WO2012023326A1 PCT/JP2011/061951 JP2011061951W WO2012023326A1 WO 2012023326 A1 WO2012023326 A1 WO 2012023326A1 JP 2011061951 W JP2011061951 W JP 2011061951W WO 2012023326 A1 WO2012023326 A1 WO 2012023326A1
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Prior art keywords
value
backlight
backlight controller
reference value
light
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PCT/JP2011/061951
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English (en)
Japanese (ja)
Inventor
西村　晃一
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シャープ株式会社
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Publication of WO2012023326A1 publication Critical patent/WO2012023326A1/fr

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
    • G09G3/3426—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines the different display panel areas being distributed in two dimensions, e.g. matrix
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G09G2320/064—Adjustment of display parameters for control of overall brightness by time modulation of the brightness of the illumination source
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G09G2320/0646—Modulation of illumination source brightness and image signal correlated to each other
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/16—Calculation or use of calculated indices related to luminance levels in display data

Definitions

  • the present invention relates to a backlight controller used to control a backlight, and an image display apparatus provided with the same.
  • a backlight controller used to control a backlight is used as one of components of an image display device, for example.
  • correspondsly controls the light emission luminance of each light source is proposed as what respond
  • the screen is divided into a plurality of areas (each located in front of the corresponding light source) to correspond one-to-one with each light source, and the light emission luminance of each light source is set. It has been proposed to control the signal according to the luminance component of the corresponding area (the luminance indicated by the image signal).
  • the light emission luminance of all the light sources is increased by increasing the light emission luminance for the light source corresponding to the region where the luminance component is high and decreasing the light emission luminance for the light source corresponding to the region where the luminance component is low. Compared to the case of equalizing, an efficient backlight unit is realized.
  • Patent Document 1 discloses, for example, a technique for more appropriately controlling the light emission luminance of each light source in consideration of this.
  • Patent Document 1 a plurality of light sources of the backlight are provided, and further, a region (A1 to A6) is provided.
  • data of the luminance contribution rate to each area for each light source is stored. Then, it is supposed that the luminous rate of each light source can be obtained by solving the multiple simultaneous equations (inequalities) shown in the equations (2) to (7).
  • the light emission rates of the respective light sources are calculated using the data of the luminance contribution rate provided to correspond to each region in a plurality of light sources.
  • the number of light sources is small with respect to the size of the display screen, that is, when the area of each area is large, the actual position may be determined depending on the point within that area, even within the same area.
  • the luminance contribution rates differ greatly. Therefore, according to the related art, there is a possibility that the calculation for obtaining the light emission luminance can not be performed accurately (finely).
  • the present invention calculates the light emission luminance of each light source in consideration of the diffusion of the backlight emitted by each light source, but provides the necessary amount of backlight to each part of the display screen. It is an object of the present invention to provide a backlight controller that can reduce power consumption as much as possible.
  • the backlight controller is a backlight controller provided in an image display apparatus having a plurality of light sources for emitting backlight and a display screen for displaying an image by adjusting the degree of transmission of the backlight.
  • a reference value setting unit configured to set, for each of a plurality of points provided on the display screen, a reference value regarding the amount of backlight based on an image signal representing the image;
  • a light emission luminance calculation unit for calculating the light emission luminance of each of the light sources using reference data, wherein the reference data includes, for each of the light sources, the light emission luminance of the light source and each of the light sources at the points.
  • Data indicating the relationship between the amount of backlight given to the light source and the light emission luminance calculation unit, and the light emission luminance calculation unit uses the predetermined calculation method to determine the back light given to each of the points.
  • Emission luminance of each of the light sources does not exceed a predetermined maximum value, and the emission luminance of each of the light sources is controlled so as not to fall below the corresponding reference value.
  • the light emission luminance of each of the light sources is calculated so as to minimize the sum of
  • the reference value setting unit detects the luminance component represented by the image signal for each point, and sets the reference value for each point to a predetermined peak value for the point. The value calculated by multiplying the ratio of the luminance component to the maximum value of the luminance component is set.
  • the reference value setting unit detects the luminance component represented by the image signal for each point, and sets the reference value for each point to a predetermined peak value for the point.
  • the value temporarily calculated by multiplying the ratio between the luminance component and the maximum value of the luminance component is provisionally set, and when the average value of the values temporarily set does not exceed a predetermined upper limit value, the provisional value
  • Each set value is set as the reference value, and when it exceeds the upper limit value, each temporarily set value is multiplied by a fixed value so that the average value does not exceed the upper limit value.
  • Each value may be set as the reference value.
  • this configuration it is possible to restrict the reference value to the determined peak value and further restrict the average value of the reference values to the determined upper limit value while adjusting the ratio of the reference value of each point to the image signal. It becomes possible. Therefore, according to the present configuration, by appropriately determining the peak value and the upper limit value, it is possible to more reliably ensure that the power consumption abnormally increases while matching the reference value of each point to the image signal as much as possible. It is possible to prevent.
  • the constant value may be a ratio of the upper limit value and the average value. According to this configuration, it is possible to prevent the reference value from being reduced more than necessary by performing excessive correction.
  • a weight coefficient relating to the amount of backlight is set for each of the points, and the reference value setting unit detects, for each of the points, the luminance component represented by the image signal.
  • the reference value of is set to a value calculated by multiplying a predetermined peak value by the ratio of the luminance component at that point to the maximum value of the luminance component and the weight coefficient for that point It may be
  • the weight coefficient is relatively small for the portion with low degree of attention, thereby giving the observer as little discomfort as possible. As a result, it is possible to further reduce power consumption.
  • the weight coefficient may be set to a smaller value as it approaches the outer edge from the approximate center of the display screen.
  • the points may be provided more than the light sources. According to this configuration, the calculation for obtaining the light emission luminance is performed more accurately (in the case where the points correspond to the light sources in one-to-one correspondence (in this case, the points and the light sources become the same number)) Can be done finely).
  • the light emission luminance calculation unit may calculate the sum of the calculated light emission luminances such that the sum does not exceed the limit value if the sum exceeds the predetermined limit value. Each of the light emission luminances may be corrected.
  • light emission of the light source may be controlled by PWM control, and light emission luminance of the light source may be represented as a duty ratio in the PWM control.
  • An image display apparatus includes the backlight controller according to the above configuration, the light source, and the display screen. According to this configuration, it is possible to receive the advantage of the backlight controller according to the above configuration. Further, more specifically, the image display device having the configuration may be a liquid crystal display device in which the display screen is formed as a liquid crystal display panel.
  • the required amount of backlight is provided to each part of the display screen by causing each of the light sources to emit light in accordance with the light emission luminance calculated by the light emission luminance calculator. Power consumption can be reduced as much as possible.
  • the image display device of the present invention it is possible to receive the advantages of the backlight controller of the present invention.
  • FIG. 1 is a block diagram of a television broadcast receiver according to an embodiment of the present invention. It is an explanatory view about a configuration of a liquid crystal panel unit and a back light unit concerning an embodiment of the present invention. It is explanatory drawing regarding a diffusion coefficient. It is a flowchart regarding operation
  • FIG. 1 is a schematic block diagram of the television broadcast receiver.
  • the television broadcast receiver 1 includes a control unit 10, an operation unit 11, a broadcast receiving unit 12, a broadcast signal processing unit 13, an image signal processing unit 14, a liquid crystal panel unit 15, a backlight unit 16 and the like. Is equipped.
  • the control unit 10 controls each unit of the television broadcast receiver 1 to execute various processes necessary to exhibit the function of the television broadcast receiver 1 (such as the function of displaying an image of television broadcast).
  • the operation unit 11 also includes a switch operated by the user, and transmits the operation content to the control unit 10. As a result, it is possible to reflect the user's intention on various operations of the television broadcast receiver 1.
  • the broadcast receiving unit 12 includes an antenna, a tuner device, and the like, and continuously receives a broadcast signal transmitted from a television broadcast station.
  • the broadcast channel to be selected is controlled by the control unit 10.
  • the received broadcast signal is sent to the broadcast signal processing unit 13.
  • the broadcast signal processing unit 13 extracts an image signal and an audio signal from the broadcast signal and sends the image signal to the image signal processing unit 14, and generates an audio signal by a speaker device (not shown based on the audio signal Device)).
  • the image signal processing unit 14 performs necessary processing (for example, processing for canceling compression and processing for correcting color tone) on the image signal received from the front stage side.
  • the image signal subjected to such processing is continuously transmitted to the liquid crystal panel unit 15 and the backlight unit 16.
  • the image signal is composed of a signal representing the luminance (luminance component) of each pixel, a synchronization signal, a clock signal, and the like.
  • the information of each frame constituting the moving image (information specifying the display content of each frame, the timing to be displayed, etc.) is continuously transmitted to the liquid crystal panel unit 15 and the backlight unit 16. .
  • the liquid crystal panel unit 15 includes a liquid crystal display panel 15a and a panel driver 15b.
  • the backlight unit 16 further includes a backlight controller 21, an LED driver 22, a plurality of LEDs 23, an LED mounting board 24, and the like.
  • the configuration of the liquid crystal panel unit 15 and the backlight unit 16 is as shown in FIG.
  • the liquid crystal display panel 15a has the same configuration as a general liquid crystal display panel having a plurality of pixels (having pixel electrodes disposed opposite to each other with liquid crystal interposed therebetween), an RGB color filter corresponding to each pixel, and the like. It has become.
  • the voltage of each pixel electrode is adjusted, and as a result, the transmission degree (aperture ratio) of a given backlight is adjusted for each pixel.
  • the target pixels 15c are provided with m pieces from the first to the m-th, and are arranged at substantially constant intervals so as to be evenly arranged on the liquid crystal display panel 15a. ing.
  • the meaning of the pixel of interest 15c will be clarified in the following description.
  • the panel driver 15 b adjusts the voltage of each pixel electrode in the liquid crystal display panel 15 a based on the image signal received from the image signal processing unit 14. More specifically, the panel driver 15b sets the voltage of each pixel electrode according to the data after obtaining image data of a new one frame. Accordingly, when the backlight is illuminated from the back side of the liquid crystal display panel 15a, an image is displayed on the liquid crystal display panel 15a.
  • Each LED 23 is connected to the LED driver 22, and the light emission of each LED 23 is controlled by PWM control. More specifically, the LED driver 22 is set so that the duty ratio in PWM control (hereinafter, simply referred to as "duty ratio”) can be updated for each LED 23, and the current is supplied to each LED 23 according to this duty ratio Let's do it.
  • duty ratio the duty ratio in PWM control
  • each LED 23 emits light with emission luminance according to the duty ratio corresponding to itself.
  • the setting of the duty ratio for each LED 23 is updated according to the transmission of the PWM signal (which represents the duty ratio for each LED 23 as described later) from the backlight controller 21.
  • the LED 23 functions as a light source of the backlight, and is disposed on the LED mounting substrate 24 (a substrate attached to the back side of the liquid crystal display panel 15a).
  • the LED 23 for example, a white LED that emits white light is used. Further, as the amount of current supplied to the LED 23 is larger (in the case of PWM control, the duty ratio is larger), the light emission luminance is higher.
  • the LED 23 is an example of a light source, and other types of light sources may be adopted as long as the emission brightness can be controlled.
  • each of the LEDs 23 can also be viewed as being arranged to correspond to a certain area on the liquid crystal display panel 15a (the area indicated by the broken line in FIG. 2). Although each LED 23 provides backlighting around an area corresponding to itself, the light emitted from the LED 23 diffuses more widely, so that backlighting is provided outside the area corresponding to itself.
  • the number (m) of the target pixels 15 c is sufficiently larger than the number (n) of the LEDs 23.
  • the position and the number of the target pixel 15 c can be set arbitrarily, independently of the position and the number of the LEDs 23.
  • the backlight controller 21 generates a PWM signal based on the image signal received from the image signal processing unit 14 so that the emission luminance of each LED 23 becomes appropriate, and outputs the PWM signal to the LED driver 22.
  • the backlight controller 21 has a function of controlling the light emission luminance of each LED 23 (in other words, the brightness of the backlight). The operation performed by the backlight controller 21 will be described again in detail. Further, as described above, the television broadcast receiver 1 can be viewed as a kind of liquid crystal display device.
  • the amount of backlight (the amount of light) given to each pixel (point) on the liquid crystal display panel 15a is the total amount of backlights given to each pixel (total Can be viewed as
  • the amount of backlight given to a certain pixel is larger, it is possible to make that pixel have higher luminance. Therefore, the amount of backlight that the LED 23 applies to a pixel can also be viewed as the degree of contribution to the luminance of the pixel.
  • the amount of backlight given to each pixel by this light emission (which can also be regarded as the degree of diffusion of the backlight) is determined by the light emission luminance at that time. Therefore, in the present embodiment, when the i-th (where 1 ⁇ i ⁇ n) LED 23 emits light with a duty ratio of 100%, this light is j-th (where 1 ⁇ j ⁇ m).
  • the amount of backlight to be given to the pixel of interest 15c may be used as the diffusion coefficient p (i, j).
  • the total amount S (j) of backlights given to the j-th target pixel 15c when each LED 23 emits light is expressed by the following equation (1).
  • d (i) represents the duty ratio in the i-th LED 23.
  • the diffusion coefficient usually takes one or a plurality of local maximum values in the vicinity of the lighting point (a pixel located approximately right in front of the LED 23), and monotonously decreases as it goes away from the local point. Moreover, since the light emitted from the LED 23 is reflected by a wall surface or the like, the diffusion coefficient fluctuates depending on where the same LED 23 is disposed.
  • FIG. 3 shows an example of the diffusion coefficient p ( ⁇ , j) for the ⁇ -th LED 23 (which is assumed to be disposed at a corner on the LED mounting substrate 24).
  • the maximum value of the diffusion coefficient in one area is 0.06273 (coordinate 0, 0), the minimum value is 0.053788 (coordinate 9, 9), and the ratio of these is 0.875. It has become.
  • the difference in the diffusion coefficient in one area increases as the number of areas (that is, the number of LEDs 23) decreases.
  • the diffusion coefficient can be obtained in advance by experiment or calculation as soon as the main specifications of the liquid crystal display panel 15a and the backlight unit 16 are determined.
  • the diffusion coefficients for all the target pixels 15 c for all the LEDs 23 are obtained in advance, and the information is recorded in the backlight controller 21.
  • the information on the diffusion coefficient recorded is used to calculate the light emission luminance of the LED 23 as described later.
  • the backlight controller 21 executes a predetermined series of operations (steps S1 to S5) as an operation of appropriately controlling the light emission luminance of the LED 23.
  • the series of operations will be described below with reference to the flowchart shown in FIG.
  • the backlight controller 21 sets a reference value L (j) regarding the amount of backlight for each of the pixels of interest 15c (step S1).
  • the reference value L (j) represents the amount of backlight to be given to the target pixel 15c when the liquid crystal display panel 15a displays an image.
  • the reference value L (j) is set as follows (an example in which a different form is adopted will be described later as the second and third embodiments).
  • the backlight controller 21 detects the luminance component Y (j) for each pixel of interest 15 c represented by the image signal received from the image signal processing unit 14. Further, the backlight controller 21 specifies the maximum value Y_max in the luminance component Y (j).
  • the backlight controller 21 calculates the reference value L (j) of each target pixel 15 c using the following equation (2).
  • L (j) L_peak ⁇ ⁇ Y (j) / Y_max ⁇ ...
  • L_peak is predetermined as a value to be used as the peak value of the reference value L (j).
  • L_peak is, for example, a total amount of backlight given to a pixel at a certain position or a corresponding amount (for example, a certain margin) when all LEDs 23 emit light with the maximum duty ratio. It is defined as a value representing a reduction by a fixed amount.
  • the backlight controller 21 sets the reference value L (j) to each value calculated using the equation (2). Thus, the operation of step S1 is realized. Thereafter, the backlight controller 21 calculates the duty ratio for each LED 23 using the information of the diffusion coefficient p (i, j) and the reference value L (j) described above (step S2).
  • d (i) represents the duty ratio of the i-th LED 23
  • S (j) represents the total amount of backlight given to the j-th target pixel 15c (see the equation (1) described above). It represents.
  • this calculation is performed using a predetermined calculation method (algorithm), and an optimum solution is obtained by this calculation method.
  • a calculation method a simplex method, an internal division method, and the like are already known, and one of them may be used, or another calculation method may be used. Further, as apparent from the contents of this calculation, the amount of calculation increases as the number of pixels of interest 15c increases, but each value of d (i) is more accurately determined (at each position of the liquid crystal display panel 15a). It is possible to determine the situation more carefully.
  • the backlight controller 21 determines whether the calculation result is in an excess state (step S3). More specifically, the backlight controller 21 determines whether the calculated sum of d (i) exceeds the preset limit value (that is, the exceeded state is regarded as an excess state). Do.
  • the limit value is a value set for ensuring safety so that the power handled by the backlight unit 16 is not excessive.
  • the limit value may be a value corresponding to the time when all the LEDs 23 are lit.
  • the backlight controller 21 corrects the calculation result so that the excess state is eliminated (step S4).
  • This correction is realized, for example, by multiplying (that is, scaling) each of d (i) with a fixed correction value such that the sum of d (i) is equal to or less than the limit value.
  • the backlight controller 21 After the correction is performed, or when the calculation result is not in the excessive state (N in step S3), the backlight controller 21 generates a PWM signal reflecting the current calculation result, and the LED is generated. It outputs to the driver 22 (step S5). Thereby, the duty ratio for each LED 23 set in the LED driver 22 is updated according to this PWM signal. As a result, thereafter, the i-th LED 23 emits light at the emission luminance corresponding to d (i) calculated this time.
  • information (for example, a PWM signal) which can determine the brightness of the backlight determined by the backlight controller 21 is transmitted to the panel driver 15b.
  • the panel driver 15b changes the amount of change in the amount of backlight provided for each pixel or area of the liquid crystal display panel 15a based on the transmitted information (for example, when the emission luminance of all the LEDs 23 is maximum) Specify the amount of change when using
  • the panel driver 15b corrects the voltage of each pixel electrode in the liquid crystal display panel 15a according to the amount of change. That is, the aperture ratio of each pixel is corrected as much as the amount of backlight changes. Thereby, the image is correctly displayed on the liquid crystal display panel 15a.
  • the method of expressing the duty ratio in the PWM signal is not particularly limited.
  • the timing of executing the above-described series of operations can be in various forms. For example, it may be performed periodically, such as every one or a plurality of frames of an image signal to be sent, or every certain time.
  • the duty ratio d (i) is set in consideration of the diffusion of the backlight emitted from each LED 23 (extending outside the corresponding area). It is calculated. Therefore, it is possible to reduce the average value of the duty ratio d (i) and to reduce the power consumption for the backlight, while ensuring the necessary brightness in the image display.
  • the duty ratio for each LED 23 is calculated based on the average brightness value of the image in the corresponding area, that is, a method for calculating the duty ratio without considering the diffusion of the backlight (hereinafter, for convenience)
  • the duty ratio d (i) is calculated to the values shown in the table of FIG.
  • Each position (9 horizontal ⁇ 5 vertical) in the table corresponds to the position of the LED 23. That is, the value of the i-th position in the table represents the duty ratio d (i).
  • the duty ratio d (i) is represented by a value from 0 (0%) to 4095 (100%).
  • the average value of the calculated duty ratio d (i) is about 31%. That is, in this case, the power consumption required for the light emission of all the LEDs 23 is theoretically about 31% of the total lighting state (the state in which all the LEDs 23 are lit at a duty ratio of 100%).
  • the duty ratio d (i) is calculated to the value shown in the table of FIG.
  • the average value of the calculated duty ratio d (i) is about 18%. That is, in this case, the power consumption required for light emission of all the LEDs 23 is theoretically about 18% of the total lighting state. Therefore, when the present calculation method is used, the power consumption required for light emission of all the LEDs 23 is suppressed to about 58% of when the general calculation method is used.
  • the duty ratio d (i) is calculated to the value shown in the table of FIG. According to FIG. 9, when the general calculation method is used, the average value of the calculated duty ratio d (i) is about 49%. That is, in this case, the power consumption required for the light emission of all the LEDs 23 is theoretically about 49% of the total lighting state.
  • the duty ratio d (i) is calculated to the value shown in the table of FIG. According to FIG. 10, when this calculation method is used, the average value of the calculated duty ratio d (i) is about 44%. That is, in this case, the power consumption required for the light emission of all the LEDs 23 is theoretically about 44% of the total lighting state. Therefore, when the present calculation method is used, the power consumption required for light emission of all the LEDs 23 is suppressed to about 90% of when the general calculation method is used.
  • the backlight controller 21 detects a luminance component Y (j) for each target pixel 15c represented by the image signal received from the image signal processing unit 14 (step S11). Further, the backlight controller 21 specifies the maximum value Y_max in the luminance component Y (j).
  • the backlight controller 21 calculates a temporary reference value L ′ (j) of each target pixel 15c using the following equation (5) (step S12).
  • L ′ (j) L_peak ⁇ ⁇ Y (j) / Y_max ⁇ ... (5)
  • L_peak is predetermined as a value to be a peak value of L (j).
  • the backlight controller 21 determines whether the average value AVE of the temporary reference values L '(j) is larger than the upper limit L_white (step S13).
  • the upper limit L_white represents the amount of backlight desired to be given to each pixel, assuming that the luminance components of the image signal are all maximum (so-called all white state).
  • the upper limit L_white is determined in advance to a predetermined value.
  • the backlight controller 21 sets each of the temporary reference values L ′ (j) to the formal reference value L (j). The setting is made (step S15).
  • the backlight controller 21 performs a predetermined correction on each of the temporary reference values L ′ (j) (step S14).
  • the set value is set to a formal reference value L (j) (step S15). More specifically, each of the reference values L (j) is calculated using the following equation (6).
  • L (j) L '(j) ⁇ ⁇ L_white / AVE ⁇ ... (6)
  • the average value of L (j) substantially matches the upper limit L_white (that is, the upper limit of the average value is limited to this value).
  • each reference value L (j) is set, and the operation of step S1 is achieved.
  • the backlight controller 21 detects the luminance component Y (j) for each pixel of interest 15 c represented by the image signal received from the image signal processing unit 14. Further, the backlight controller 21 specifies the maximum value Y_max in the luminance component Y (j).
  • the backlight controller 21 calculates the reference value L (j) of each target pixel 15c using the following equation (7).
  • L (j) L_peak ⁇ ⁇ Y (j) / Y_max ⁇ ⁇ rate (j) (7)
  • L_peak is predetermined as a value to be a peak value of L (j).
  • Rate (j) represents a weight factor related to the amount of backlight for the j-th target pixel 15c.
  • the weight coefficient rate (j) is set to a predetermined value for all the pixels of interest 15c.
  • the weight coefficient is set to a smaller value as it gets closer to the outer edge from the center of the screen (liquid crystal display panel 15a) as shown in an example in FIG.
  • the weight coefficient does not lower the display brightness at the center of the screen (generally, the part at which the viewer most gazes at most), while decreasing the brightness toward the outer edge of the screen, Power reduction is set to be realized.
  • the backlight controller 21 sets the reference value L (j) to each value calculated using the equation (7). By performing the operation up to this point, each reference value L (j) is set, and the operation of step S1 is achieved.
  • the backlight controller 21 includes a plurality of LEDs 23 (light sources) that emit backlights, and a liquid crystal display panel 15a (display screen) that adjusts the degree of transmission of the backlights to display an image. And a television broadcast receiver 1 (image display device).
  • the backlight controller 21 sets a reference value L (j) relating to the amount of backlight to each of the plurality of target pixels 15c (plural points) set on the liquid crystal display panel 15a.
  • Function unit reference value setting unit
  • a function unit light emission to calculate the emission brightness of each of the LEDs 23 using the diffusion coefficient p (i, j) (reference data) preset for each of the LEDs 23 And a luminance calculation unit).
  • the diffusion coefficient p (i, j) is data representing, for each of the LEDs 23, the relationship between the emission luminance of the LED 23 and the amount of backlight given by the LED 23 to each of the target pixels 15c.
  • the light emission luminance calculation unit uses a predetermined calculation method so that the sum of the amounts of backlight given to the respective target pixels 15c does not fall below the corresponding reference value L (j) (the equation (3) described above is ) And the emission luminance of each of the LEDs 23 does not exceed a predetermined maximum value (duty ratio 100%) (refer to the above-mentioned equation (4)), and the emission luminance of each of the LEDs 23 is satisfied.
  • the light emission luminance of each of the LEDs 23 is calculated so as to minimize the sum of.
  • the backlight controller 21 calculates an optimal solution that conforms to these equations and conditions. That is, the backlight controller 21 can calculate the light emission luminance for each LED 23 so that the power consumption can be as small as possible while providing the necessary amount of backlight to each part of the liquid crystal display panel 15a. It has become.
  • the target value of the reference value L (j) is a part of a plurality of pixels included in each of the pixels of interest 15c, that is, the display screen (liquid crystal display panel 15a). I do not care.
  • the target value of the reference value L (j) is a part of a plurality of pixels included in each of the pixels of interest 15c, that is, the display screen (liquid crystal display panel 15a). I do not care.
  • the luminance component represented by the image signal is detected for each pixel of interest 15c.
  • the reference value L (j) for each pixel of interest 15c is a value calculated by multiplying the ratio of the luminance component Y (j) to the maximum value Y_max of the luminance component by a predetermined L_peak (peak value), It is set (see the equation (2) described above).
  • the backlight controller 21 it is possible to match the ratio of the reference value L (j) of each target pixel 15c to the image signal while limiting the reference value L (j) to L_peak. Therefore, according to the backlight controller 21, by appropriately determining L_peak, power consumption is abnormally increased while matching the reference value L (j) of each pixel of interest 15c to the image signal as much as possible. It is possible to prevent as much as possible.
  • the luminance component represented by the image signal is detected for each pixel of interest 15c.
  • the reference value L (j) for each pixel of interest 15c is obtained by multiplying the ratio of the luminance component Y (j) for the pixel of interest 15c to the maximum value Y_max of the luminance component by a predetermined L_peak (peak value).
  • the temporary calculated reference value L '(j) is calculated using the previously calculated value (that is, the temporary reference value L' (j) is calculated).
  • each value of L ′ (j) is set as the reference value L (j) and exceeds the upper limit L_white. If the average value AVE does not exceed the upper limit L_white, each value of L ′ (j) is multiplied by a fixed value (the ratio of the upper limit L_white to the average value AVE) and each value corrected is a reference value It sets as L (j) (refer to (6) Formula mentioned above).
  • the reference value L (j) is limited to L_peak while matching the ratio of the reference value L (j) of each pixel of interest 15c to the image signal, and further the reference value L (j) It is possible to limit the average value to L_white. Therefore, according to the backlight controller 21, by appropriately determining L_peak and L_white, the power consumption is abnormally large while the reference value L (j) of each pixel of interest 15c is matched to the image signal as much as possible. Can be prevented as much as possible.
  • a weight coefficient rate (j) related to the amount of backlight is set for each pixel of interest 15c. Then, the luminance component represented by the image signal is detected for each pixel of interest 15c. Further, the reference value L (j) for each pixel of interest 15c is a predetermined L_peak (peak value), the ratio of the luminance component Y (j) to the maximum value Y_max of the luminance component, and the weight coefficient rate j) is set to the value calculated by multiplying (refer to the previously described equation (7)).
  • the weight coefficient rate (j) is set to a smaller value as the outer edge is approached from the center of the display screen (liquid crystal display panel 15a). Generally, when the observer looks at the image on the display screen, the degree of attention of the observer decreases as the outer edge is approached from the center of the display screen.
  • the brightness of the display is not lowered as much as possible at the center of the display screen, and the viewer is not as uncomfortable as possible, while the brightness is closer to the outer edge of the display screen. Power consumption can be realized.
  • how to set the weight coefficient is not limited to such a form, and can be freely determined according to various circumstances.
  • the diffusion coefficient p (i, j) is the area even in the same area (one area corresponds to one LED 23) on the liquid crystal display panel 15a. It depends on where in the house. In particular, when the number of LEDs 23 is small with respect to the size of the display screen, that is, when the area of each area is wide, the difference becomes remarkable.
  • the number of target pixels 15c is larger than that of the LEDs 23, and a plurality of target pixels 15c are allocated to one area. Therefore, according to the backlight controller 21 of the present embodiment, it is possible to perform the calculation for obtaining the light emission luminance of each LED 23 more accurately (more finely).
  • the present invention can be used for various image display devices that display an image using a backlight.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Liquid Crystal (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

La présente invention se rapporte à un contrôleur de rétroéclairage comprenant : un module de paramétrage de valeurs de référence qui paramètre, sur la base de signaux d'image, des valeurs de référence pour une pluralité de points sur un écran d'affichage, respectivement ; et un module de calcul de luminosité d'émission de lumière qui calcule la luminosité d'émission de lumière de chacune des sources de lumière au moyen de données de référence de chacune des sources de lumière. Les données de référence indiquent, en rapport avec chacune des sources de lumière, une relation entre la luminosité d'émission de lumière de chacune des sources de lumière et la quantité de rétroéclairage appliqué sur chacun des points par la source de lumière. Le module de calcul de luminosité d'émission de lumière calcule des luminosités d'émission de lumière au moyen d'un procédé de calcul prédéterminé, de telle sorte que le total des luminosités d'émission de lumière soit minimum tout en remplissant les conditions selon lesquelles la quantité totale du rétroéclairage appliqué sur les points ne doit pas être inférieure à la valeur de référence correspondante et selon lesquelles la luminosité d'émission de lumière de chacune des sources de lumière ne doit pas dépasser la valeur maximale.
PCT/JP2011/061951 2010-08-17 2011-05-25 Contrôleur de rétroéclairage et dispositif d'affichage d'image WO2012023326A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015072257A1 (fr) * 2013-11-12 2015-05-21 富士フイルム株式会社 Dispositif d'affichage et son procédé de commande

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI492012B (zh) * 2012-07-24 2015-07-11 Himax Media Solutions Inc 背光亮度調整方法及裝置
CN103594061A (zh) * 2012-08-17 2014-02-19 承景科技股份有限公司 背光亮度调整方法及装置
US9311863B2 (en) 2013-07-02 2016-04-12 Novatek Microelectronics Corp. Dimming method and dimming device for backlight module

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007034251A (ja) * 2005-03-24 2007-02-08 Sony Corp 表示装置及び表示方法
JP2008026816A (ja) * 2006-07-25 2008-02-07 Toshiba Corp カラー表示装置およびカラー表示方法
WO2009004574A1 (fr) * 2007-07-04 2009-01-08 Koninklijke Philips Electronics N.V. Ppprocédé et système pour commander un rétro-éclairagerétroéclairage dans un dispositif d'affichage

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007034251A (ja) * 2005-03-24 2007-02-08 Sony Corp 表示装置及び表示方法
JP2008026816A (ja) * 2006-07-25 2008-02-07 Toshiba Corp カラー表示装置およびカラー表示方法
WO2009004574A1 (fr) * 2007-07-04 2009-01-08 Koninklijke Philips Electronics N.V. Ppprocédé et système pour commander un rétro-éclairagerétroéclairage dans un dispositif d'affichage

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015072257A1 (fr) * 2013-11-12 2015-05-21 富士フイルム株式会社 Dispositif d'affichage et son procédé de commande
JP6023349B2 (ja) * 2013-11-12 2016-11-09 富士フイルム株式会社 表示装置及びその制御方法
US9818346B2 (en) 2013-11-12 2017-11-14 Fujifilm Corporation Display device and control method for same

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TWI430240B (zh) 2014-03-11

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