JP6351376B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of suppressing a change in white balance (chromaticity) due to age-related deterioration of a light source, temperature characteristics, and the like.

  The liquid crystal display element included in the liquid crystal display device does not emit light by itself. For this reason, the liquid crystal display device includes a backlight device on the back surface of the liquid crystal display element as a light source that emits light to the liquid crystal display element. For example, in Patent Document 1, a light emitting diode (LED) of three primary colors is provided in a backlight device, and the chromaticity of backlight light (illumination light) is adjusted by adjusting the light amount (light emission intensity) of each color LED. A liquid crystal display device is disclosed.

JP 2001-135118 A

  Now, in recent years, a light source that emits light of one primary color among the three primary colors of red, green, and blue by an LED and the like, and causes the phosphor to absorb the light to emit light of other primary colors or two primary colors, Devices for use in backlights have been proposed. However, in general, when a phosphor is used for a long time, the luminance of light emitted from the phosphor deteriorates, and the luminance and chromaticity of the entire backlight change.

  In particular, in the configuration in which light of two primary colors is emitted using two phosphors, the deterioration rates of the phosphors that generate light in the wavelength regions of the respective primary colors are different, so the balance of the light amounts of the three primary colors (light emission characteristics). The secular change of becomes remarkable. Further, since the temperature characteristics of the phosphors are also different, the balance (light emission characteristics) of the light amounts of the three primary colors also exists in the temperature dependence. For this reason, in the liquid crystal display device using the light source as described above, the balance (light emission characteristics) of the light amounts of the three primary colors, that is, the white balance (chromaticity) deteriorates no matter how appropriately the light emission intensity of the light source is adjusted. There was a problem of doing.

  Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a technique capable of suppressing a change in chromaticity of a liquid crystal display device.

  The liquid crystal display device according to the present invention includes at least one of light of the first primary color among the three primary colors of red, green, and blue and the second primary color and the third primary color having an intensity depending on the intensity of the light of the first primary color. A first light source that emits light of one primary color, and a light amount detector that detects a light amount of the first primary color emitted from the first light source and a light amount of the at least one primary color. Further, the liquid crystal display device is a light source that controls the intensity of light emitted by the first light source based on the light amount of the first primary color detected by the light amount detection unit or the light amount of the at least one primary color. Based on the light amount of the first primary color detected by the control unit and the light amount detection unit and the light amount of the at least one primary color, the liquid crystal display unit displays the light emitted from the first light source. An image controller configured to adjust a dynamic range of the first primary color or the at least one primary color of an image.

  ADVANTAGE OF THE INVENTION According to this invention, the change of the chromaticity of a liquid crystal display device can be suppressed.

2 is a block diagram schematically showing functions of the liquid crystal display device according to Embodiment 1. FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal display device according to Embodiment 1. FIG. 1 is a plan view showing a schematic configuration of a liquid crystal display device according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a spectral distribution of a light source according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a spectral distribution of a light source according to Embodiment 1. FIG. 3 is a flowchart illustrating an operation of the liquid crystal display device according to the first embodiment.

<Embodiment 1>
FIG. 1 is a block diagram schematically showing a function (configuration) of a liquid crystal display device 10 according to Embodiment 1 of the present invention. In FIG. 1, a liquid crystal display device 10 includes a first light source 11, a second light source 12, a light source driving unit 13, a reference value storage unit 14, a light mixing unit 15, a display control unit 16, and a liquid crystal display unit. 17, a light amount detection unit 18, and an MPU (Micro-Processing Unit) 19 that comprehensively controls them.

  The first light source 11 includes light of the first primary color among the three primary colors of red, green, and blue, and at least one primary color of the second primary color and the third primary color having an intensity depending on the intensity of the light of the first primary color. Emits light. In the following, the first light source 11 emits blue light (first primary color light) and green light (second primary color light) having an intensity depending on the intensity of the blue light at the same time. A configuration for emitting the color light CL will be described as an example. In the following description, it is assumed that the light intensity and the light amount have substantially the same meaning.

  In the first embodiment, the first light source 11 absorbs part of the emitted light from the blue LED light source group, which is a semiconductor light emitting element that emits light in the blue wavelength range, and the blue LED light source group as excitation light. And a green phosphor that emits light in the green wavelength range. The green phosphor is filled in the light emission region of the blue LED light source group. According to the 1st light source 11 comprised in this way, the emitted light (blue light) of a blue LED light source group and the excitation light (green light) of the green fluorescent substance whose intensity depends on the said emitted light are mixed. Thus, it becomes possible to emit cyan light (blue-green light) CL.

  The second light source 12 emits red light (third primary color light) RL having an intensity independent of the intensity of the blue light of the first light source 11. As the second light source 12, for example, a red laser light source group that emits light in a red wavelength region is applied. In addition, according to the structure which applied the red laser light source group to the 2nd light source 12, in the image (display image) which the liquid crystal display part 17 displays, the purity of red can be raised and the color reproduction range can be expanded. It becomes possible.

  The light source drive unit 13 includes a first drive circuit 13 a that drives the first light source 11 and a second drive circuit 13 b that drives the second light source 12. The light source driving unit 13 configured as described above controls the intensity of the cyan light CL emitted from the first light source 11 and the intensity of the red light RL emitted from the second light source 12 under the control of the MPU 19.

  The reference value storage unit 14 includes a reference value for the MPU 19 to control the light emitted from the first light source 11 and the second light source 12 via the light source driving unit 13, and white balance (chromaticity) in the liquid crystal display device 10. Is stored as a reference value. Here, as these reference values, a reference value Br for blue light, a reference value Gr for green light, and a reference value Rr for red light are stored in the reference value storage unit 14.

  The light mixing unit 15 mixes the cyan light CL emitted from the first light source 11 and the red light RL emitted from the second light source 12 to generate white illumination light ML, and the illumination light ML is liquid crystal. The light is emitted to the display unit 17.

  The display control unit 16 generates a control signal for controlling the liquid crystal display unit 17 by performing image processing on a digital or analog input image signal (video signal) under the control of the MPU 19.

  The liquid crystal display unit 17 includes, for example, a liquid crystal panel and the like, and uses the illumination light ML (cyan light emitted from the first light source 11 and red light emitted from the second light source 12) from the display control unit 16. An image corresponding to the control signal is displayed.

  The light amount detector 18 detects the amount of cyan light CL (blue light and green light) emitted from the first light source 11. Here, it is assumed that the light amount detection unit 18 detects a light amount of the cyan light CL included in a part of the illumination light ML by receiving a part of the illumination light ML. Similarly, the light amount detector 18 also detects the light amount of the red light RL included in a part of the illumination light ML.

<Mechanical structure>
Next, a part of the mechanical structure of the liquid crystal display device 10 will be described. FIG. 2 is a cross-sectional view illustrating an example of a schematic configuration of part of the liquid crystal display device 10. The light mixing unit 15 is disposed on the back side of the liquid crystal display unit 17, and the liquid crystal display device 10 includes a first and a first that disperse the traveling direction of light between the light mixing unit 15 and the liquid crystal display unit 17. Second optical sheets 21 and 22 are provided.

  The first light source 11, the second light source 12, and the light mixing unit 15 constitute a surface light source device that irradiates light to the back surface of the liquid crystal display unit 17 through the first and second optical sheets 21 and 22. 2 includes a light guide plate 23, a light guide plate 24, and a reflection sheet 25. A first optical sheet 21, a second optical sheet 22, a light guide plate 23, a light guide plate 24, and a reflection sheet 25 are arranged in order from the liquid crystal display unit 17.

  The first light source 11 is disposed to face a pair of both side surfaces of the light guide plate 23. The cyan light CL that is incident on the side surface of the light guide plate 23 from the first light source 11 is converted by the light guide plate 23 into planar light that travels in the Z-axis direction (the vertical direction on the paper surface).

  Similarly, the second light source 12 is disposed to face both side surfaces of the light guide plate 24. The red light RL incident on the side surface of the light guide plate 24 from the second light source 12 is converted by the light guide plate 24 into planar light that goes in the Z-axis direction (vertical direction on the paper surface).

  The light mixing unit 15 including the light guide plates 23 and 24 mixes two types of light (cyan light CL and red light RL) emitted from the first light source 11 and the second light source 12 to form a planar shape. White illumination light ML is generated, and the illumination light ML is supplied to the liquid crystal display unit 17.

  FIG. 3 is a plan view showing an example of a schematic configuration of a part of the liquid crystal display device 10 when the light guide plate 23 (light mixing unit 15) is viewed from the liquid crystal display unit 17 side. The light guide plate 24 and the like disposed below the light guide plate 23 are hidden by the light guide plate 23 in a plan view of FIG. As shown in FIG. 3, the first light source 11 and the second light source are alternately arranged along both side surfaces of the light guide plate 23 (light guide plate 24) in plan view. According to such a configuration, the distribution of the light amount of the planar illumination light ML can be made uniform.

  The first light source 11 may be disposed on the reflection sheet 25 so that the cyan light CL can be irradiated in the Z-axis direction, and a lens or the like for diffusing the cyan light CL may be used instead of the light guide plate 23. . Further, the first light source 11 may be arranged in the same manner as in FIG. 2, and a plurality of columnar light guides arranged on a single plane may be used instead of the light guide plate 23. Note that these modifications can be applied to the second light source 12 and the light guide plate 24 in the same manner.

  Returning to FIG. 2, the reflection sheet 25 reflects the light that travels in the direction opposite to the liquid crystal display unit 17 out of the illumination light ML that travels in the Z-axis direction so as to travel in the direction of the liquid crystal display unit 17. According to such a reflection sheet 25, the illumination light ML can be used as much as possible. Here, a through hole 25a is provided in a part of the reflection sheet 25, and the light amount detector 18 can receive a part of the illumination light ML through the through hole 25a. Yes.

  The light amount detection unit 18 converts, for example, an optical sensor having a red color filter, an optical sensor having a blue color filter, an optical sensor having a green color filter, and outputs of these optical sensors into three digital signals. A color sensor provided with an A / D converter is applied. The light amount detection unit 18 includes a digital signal indicating a light amount detection value Rd which is a detection result of a light component in the red wavelength region, a digital signal indicating a light amount detection value Bd which is a detection result of the light component in the blue wavelength region, and a green wavelength. The digital signal indicating the light amount detection value Gd, which is the detection result of the light component in the region, is output to the MPU 19 in parallel. Here, the light amount detection values Bd and Gd are detection values mainly obtained from the cyan light CL emitted from the first light source 11, and the light amount detection value Rd is derived from the red light RL emitted from the second light source 12. This is the detection value obtained mainly.

<Light source control unit>
In the first embodiment, the light source driving unit 13, the reference value storage unit 14, and the MPU 19 constitute a light source control unit. The light source control unit controls the intensity of light emitted from the first light source 11 based on the light amount detection value Gd (green light amount) detected by the light amount detection unit 18. The light source control unit controls the intensity of the light emitted from the second light source 12 based on the light amount detection value Rd (red light amount) detected by the light amount detection unit 18.

  Hereinafter, the light source drive unit 13, the reference value storage unit 14, and the MPU 19 that constitute the light source control unit having such a function will be described.

  The MPU 19 individually drives the first and second drive circuits 13a and 13b of the light source drive unit 13 according to the light quantity detection values Gd and Rd input from the light quantity detection unit 18, thereby increasing the intensity of the illumination light ML. adjust. Here, the MPU 19 calculates a difference ΔG indicating a deviation of the light amount detection value Gd from the reference value Gr from the light amount detection value Gd and the reference value Gr stored in the reference value storage unit 14. Similarly, the MPU 19 calculates a difference ΔR indicating a deviation of the light amount detection value Rd from the reference value Rr from the light amount detection value Rd and the reference value Rr stored in the reference value storage unit 14. The differences ΔG and ΔR are calculated according to the following equation (1), for example.

  When the first drive circuit 13a of the light source drive unit 13 receives a control value for keeping the value of ΔG calculated by the MPU 19 within a certain range from the MPU 19, the blue LED light source of the first light source 11 according to the control value. The light intensity of the first light source 11 is adjusted by controlling the drive current Ic supplied to the group. That is, the first drive circuit 13a adjusts the intensity of green light of the first light source 11. However, since the intensity of the green light depends on the intensity of the blue light, adjusting the intensity of one of the green light and the blue light is substantially the intensity of the other light, and thus the intensity of both lights. Will also adjust.

  Similar to the first drive circuit 13a, the second drive circuit 13b of the light source drive unit 13 receives a control value for keeping the value of ΔR calculated by the MPU 19 within a certain range from the MPU 19, and according to the control value. The intensity of red light of the second light source 12 is adjusted by controlling the drive current Ir supplied to the second light source 12 (red laser light source group).

  According to the light source control unit configured by the light source driving unit 13, the reference value storage unit 14, and the MPU 19 as described above, the light amount of the green component and the light amount of the red component included in the illumination light ML mixed by the light mixing unit 15. Can be controlled to be constant.

  However, here, the first light source 11 is assumed to be a cyan light source composed of a blue LED light source group and a green phosphor. In general, such a cyan light source has aging deterioration and temperature characteristics of the phosphor, so that even if the green phosphor absorbs blue light of the same intensity, it emits green light that is excitation light. The intensity changes. As a result, the balance between the light amount of the blue component and the light amount of the green component changes. Therefore, even if the above-described light source control unit can keep the light amount of the green component and the light amount of the red component of the illumination light ML substantially constant, the light amount of the blue component relatively changes with time. Therefore, there is a problem that the white balance (chromaticity) of the illumination light ML output from the light mixing unit 15 changes with time.

<Related equipment>
This will be described by taking a liquid crystal display device (hereinafter referred to as “related device”) related to the liquid crystal display device according to the first embodiment as an example. In the following description of the related apparatus, the same components as those of the liquid crystal display device according to the first embodiment are denoted by the same reference numerals.

  4 and 5 are diagrams illustrating an example of the spectrum of the first light source 11 in the related apparatus. The solid line in FIG. 4 shows the spectrum of the first light source 11 in the initial state, and the dotted line in FIG. As can be seen from FIG. 4, even when the intensity of the blue light absorbed by the green phosphor is the same, the emission intensity of the green light in the aged deterioration state is lower than the emission intensity of the green light in the initial state.

  Both the dotted line and the solid line in FIG. 5 indicate the spectrum of the first light source 11 in an aged deterioration state. However, the dotted line in FIG. 5 indicates a spectrum in a state where the control by the light source control unit is not performed, and the solid line in FIG. 5 indicates a spectrum in a state where the control by the light source control unit is performed. The light source control unit described above is configured so that the emission intensity of the green light that has decreased due to deterioration over time falls within a certain range from the reference value Gr (so that it is approximately the same as the emission intensity in the initial state). The emission intensity of blue light emitted from the blue LED light source group is increased.

  As a result, the emission intensity of blue light becomes relatively higher than the emission intensity of green light and the emission intensity of red light, and the white balance (chromaticity) of the illumination light ML changes. Therefore, it is difficult to keep the chromaticity constant only by controlling the first light source 11 and the second light source 12 as in the related apparatus.

<Image control unit>
On the other hand, the liquid crystal display device according to the first embodiment can solve the above problem by including an image control unit described below. The image control unit includes a reference value storage unit 14, a display control unit 16, and an MPU 19. The light amount detection value Bd (blue light amount) detected by the light amount detection unit 18 and the light amount detection value Gd (green). The dynamic range of blue in the display image on the liquid crystal display unit 17 is adjusted based on the amount of light).

  Specifically, the image control unit uses the degree of change in the ratio between the light amount detection value Bd and the light amount detection value Gd detected by the light amount detection unit 18 to display the video of the blue component of each pixel of the liquid crystal display unit 17. Correct the value. For example, when the emission intensity of blue light increases as shown in FIG. 5, the image control unit corrects the blue component of the display image on the liquid crystal display unit 17 so as to reduce the white balance of the display image. (Chromaticity) can be made constant.

  Hereinafter, the reference value storage unit 14, the display control unit 16, and the MPU 19 that constitute the image control unit having such a function will be described.

  The MPU 19 calculates a ratio GB (= Bd / Gd) from the light quantity detection values Bd and Gd input from the light quantity detection unit 18, and uses the ratio GBr (from the reference values Br and Gr stored in the reference value storage unit 14. = Br / Gr). Then, the MPU 19 calculates the blue correction coefficient Bcoef for correcting the video display value of the blue component by applying the ratio GB and the ratio GBr to the following equation (2), for example, and displays the blue correction coefficient Bcoef Output to the control unit 16. Note that TB in the following equation (2) is a constant.

  In accordance with the input image signal (video signal), the display control unit 16 displays video display values Bin, Gin, Blue (B), green (G), and red (R) of the three primary colors in each pixel of the liquid crystal display unit 17. Rin is generated respectively. Then, the display control unit 16 corrects the video display value Bin of the blue component of each pixel of the liquid crystal display unit 17 using the blue correction coefficient Bcoef calculated by the MPU 19. Here, the display control unit 16 calculates the blue component correction value Bout that is the corrected video display value Bin, for example, according to the following equation (3).

  The display control unit 16 uses the blue component correction value Bout as the control value of the blue component of the image display in the liquid crystal display unit 17, and the video display value Gin, as the control value of the green component and red component of the image display in the liquid crystal display unit 17. Rin is used. And the display control part 16 controls the image which the liquid crystal display part 17 displays based on these control values (control signal). According to the above configuration, for example, when the blue component (light quantity detection value Bd) in the illumination light ML increases relative to the green component (light quantity detection value Gd), the above equation (2) Since the blue component correction value Bcoef is reduced, a change in white balance (chromaticity) of the display image on the liquid crystal display unit 17 can be suppressed.

<Operation>
FIG. 6 is a flowchart showing the operation of the liquid crystal display device 10 according to the first embodiment. This operation is realized by the control of the light source driving unit 13, the display control unit 16, and the MPU 19.

  When the power of the liquid crystal display device 10 is turned on, the operation of step S1 in the flowchart of FIG. 6 starts at regular intervals as an interrupt process using a timer (not shown) built in the MPU 19. .

  In step S1, the light quantity detection unit 18 detects the light quantity detection values Bd, Gd, and Rd, and the MPU 19 detects the light quantity detection value Gd for the green component, the light quantity detection value Rd for the red component, and the light quantity detection value Bd for the blue component. From the light quantity detection unit 18. Thereafter, the process proceeds to step S2.

  In step S2, the MPU 19 reads the reference value Gr for the green component, the reference value Rr for the red component, and the reference value Br for the blue component from the reference value storage unit 14. Thereafter, the process proceeds to step S3.

  In step S3, the MPU 19 calculates the difference ΔG between the green component reference value Gr and the light amount detection value Gd according to the above equation (1), and calculates the difference ΔR between the red component reference value Rr and the light amount detection value Rd. calculate. Thereafter, the process proceeds to step S4.

  In step S4, the MPU 19 compares the difference ΔG with the upper limit value TU1 of the above-described certain range set for the difference ΔG. If the difference ΔG exceeds the upper limit value TU1, the process proceeds to step S5, and if it is equal to or less than the upper limit value TU1, the process proceeds to step S6.

  In step S5, the difference ΔG exceeds the upper limit value TU1, that is, the light amount detection value Gd is too large compared to the reference value Gr. Therefore, the MPU 19 outputs a control value to the first drive circuit 13a so as to reduce the amount of green light (light amount detection value Gd) by reducing the amount of blue light of the first light source 11. Thereafter, the process proceeds to step S8.

  In step S6, the MPU 19 compares the difference ΔG with the lower limit value TL1 of the above-described certain range set for the difference ΔG. If the difference ΔG is less than the lower limit value TL1, the process proceeds to step S7, and if the difference ΔG is equal to or greater than the lower limit value TL1, the process proceeds to step S8.

  In step S7, the difference ΔG is below the lower limit value TL1, that is, the light amount detection value Gd is too small compared to the reference value Gr. Therefore, the MPU 19 outputs a control value to the first drive circuit 13a so as to increase the amount of green light (light amount detection value Gd) by increasing the amount of blue light of the first light source 11. Thereafter, the process proceeds to step S8.

  In step S8, the MPU 19 compares the difference ΔR with the upper limit value TU2 of the above-described certain range set for the difference ΔR. If the difference ΔR exceeds the upper limit value TU2, the process proceeds to step S9, and if it is equal to or less than the upper limit value TU2, the process proceeds to step S10.

  In step S9, the difference ΔR exceeds the upper limit value TU2, that is, the light amount detection value Rd is too large compared to the reference value Rr. For this reason, the MPU 19 outputs a control value to the second drive circuit 13b so as to reduce the amount of red light (light amount detection value Rd) of the second light source 12. Thereafter, the process proceeds to step S12.

  In step S10, the MPU 19 compares the difference ΔR with the lower limit value TL2 of the predetermined range set for the difference ΔR. If the difference ΔR is less than the lower limit value TL2, the process proceeds to step S11. If the difference ΔR is greater than or equal to the lower limit value TL2, the process proceeds to step S12.

  In step S11, the difference ΔR is below the lower limit value TL2, that is, the light amount detection value Rd is too small compared to the reference value Rr. Therefore, the MPU 19 outputs a control value to the second drive circuit 13b so as to increase the amount of red light (light amount detection value Rd) of the second light source 12. Thereafter, the process proceeds to step S12.

  Through the above steps S1 to S11, the green component light amount detection value Gd is controlled to be within a certain range of the reference value Gr, and the red component light amount detection value Rd is controlled to be within the certain range of the reference value Rr. Is done. For this reason, the light amounts of the green and red components of the first and second light sources 11 and 12 are kept substantially constant.

  Then, in steps S12 to S15, the ratio of the blue component light amount detection value Bd and the green component light amount detection value Gd of the first light source 11 and the ratio of the green component reference value Gr and the blue component reference value Br are described above. The blue correction coefficient Bcoef is calculated. Thereafter, the blue component of the video signal is corrected by the blue correction coefficient Bcoef, so that the white balance (chromaticity) of the image (video) actually displayed on the liquid crystal display unit 17 is kept substantially constant. Become. Hereinafter, steps S12 to S15 will be described in detail.

  In step S12, the MPU 19 calculates a ratio GBr (= Br / Gr) from the reference values Gr and Br read from the reference value storage unit 14 in step S2. Thereafter, the process proceeds to step S13.

  In step S13, the MPU 19 calculates a ratio GB (= Bd / Gd) from the light quantity detection values Gd and Bd captured from the light quantity detection unit 18 in step S1. Thereafter, the process proceeds to step S14.

  In step S14, the MPU 19 calculates the blue correction coefficient Bcoef by applying the ratio GBr and the ratio GB to the above equation (2). Thereafter, the process proceeds to step S15.

  In step S <b> 15, the blue correction coefficient Bcoef is output from the MPU 19 to the display control unit 16. Then, the display control unit 16 corrects the blue component of the video signal using the blue correction coefficient Bcoef according to the above equation (3), and uses the blue component correction value Bout obtained thereby to control the blue component control value (video display Value). Then, the series of timer interrupt processing shown in FIG. 6 ends.

<Effect>
According to the liquid crystal display device 10 according to the first embodiment as described above, the first light source 11 emits light based on the green light amount (green component light amount detection value Gd) detected by the light amount detection unit 18. The intensity of light emitted from the second light source 12 is controlled on the basis of the light quantity detection value Rd of the red component detected by the light quantity detection unit 18. Thus, the luminance of the illumination light ML generated by mixing the light from the first light source 11 and the second light source 12 can be prevented from being lowered, and a certain amount of white balance (chromaticity) is adjusted. It becomes possible.

  Further, based on the blue light quantity (blue component light quantity detection value Bd) and green light quantity (green component light quantity detection value Gd) detected by the light quantity detection unit 18, the image of the image displayed by the liquid crystal display unit 17 is displayed. Adjust the blue dynamic range. Accordingly, the phenomenon of FIG. 5 in which the emission intensity of blue light becomes relatively larger than the emission intensity of green light can be suppressed, so that the white balance (color) of the display image on the liquid crystal display unit 17 can be suppressed. Degree) can be suppressed.

  That is, in the configuration using the first light source 11 that emits blue light and green light having an intensity depending on the intensity of the blue light as in the related device, only the control of the emission intensity of the first light source 11 is performed. Then, although the light quantity balance of blue light and green light could not be changed and the chromaticity could not be adjusted, according to the liquid crystal display device 10 according to the first embodiment, the blue color in the image of the liquid crystal display unit 17 Since the balance with green can be changed, the chromaticity can be adjusted.

<Modification 1>
In the first embodiment, the image control unit adjusts the blue dynamic range in the image on the liquid crystal display unit 17 based on the blue light amount detected by the light amount detection unit 18 and the green light amount. Specifically, the blue dynamic range in the image on the liquid crystal display unit 17 is adjusted to be low so that the blue light emission intensity does not become too large relative to the green light emission intensity. .

  However, the present invention is not limited to this, and the image control unit sets the green dynamic range in the image on the liquid crystal display unit 17 based on the blue light amount and the green light amount detected by the light amount detection unit 18. You may adjust. Specifically, the green dynamic range in the image on the liquid crystal display unit 17 is adjusted to be high so that the blue light emission intensity does not become too large relative to the green light emission intensity. Also good. In this case, the green component correction value Gout corresponding to the blue component correction value Bout may be calculated by the following equation (4), for example. In the following formula (4), TG is a constant.

  Also according to the first modification, it is possible to suppress a change in white balance (chromaticity) of a display image on the liquid crystal display unit 17.

<Modification 2>
In the first embodiment, the first light source 11 emits blue light (first primary color light) and green light (second primary color light) having an intensity depending on the intensity of the blue light, and the second light source. 12 is described as emitting red light (third primary color light).

  However, the present invention is not limited to this. For example, the first light source 11 emits blue light and red light having an intensity depending on the intensity of the blue light, and the second light source 12 emits green light. Also good. That is, a combination of three primary colors (blue, green, and red) can be applied to the first primary color, the second primary color, and the third primary color.

<Modification 3>
Further, the first light source 11 may include a blue LED light source group that emits blue light, a green phosphor, and a red phosphor. That is, the first light source 11 includes blue light (first primary color light), green light (second primary color light) having an intensity depending on the intensity of the blue light, and intensity depending on the intensity of the blue light. White light may be emitted by simultaneously emitting red light having a color (light of the third primary color).

  In this case, the light source control unit may suppress the light intensity of the first light source 11 based on the amount of green light detected by the light amount detection unit 18 or the red light detected by the light amount detection unit 18. The light intensity of the first light source 11 may be suppressed based on the light amount.

  Then, the image control unit adjusts the blue dynamic range in the image on the liquid crystal display unit 17 based on the blue light amount, the green light amount, and the red light amount detected by the light amount detection unit 18. Alternatively, the green and red dynamic ranges may be adjusted.

  According to the third modification, the second light source 12 and the components that control the second light source 12 are not necessary. In the third modification, a combination of the three primary colors (blue, green, and red) can be applied to the first primary color, the second primary color, and the third primary color.

<Modification 4>
In the first embodiment, the light source control unit controls the intensity of light emitted from the first light source 11 based on the light amount detection value Gd (green light amount) detected by the light amount detection unit 18. However, the present invention is not limited to this, and the light source control unit controls the intensity of the light emitted from the first light source 11 based on the light amount detection value Bd (the amount of blue light) detected by the light amount detection unit 18. Also good.

<Modification 5>
In the configuration described above, for example, color adjustment using a spectral radiance meter or the like is performed at a predetermined reference temperature at the manufacturing stage of the liquid crystal display device 10, and color measurement measured immediately thereafter is performed. The values may be stored in the reference value storage unit 14 as reference values Gr, Rr, Br. By using such values, even if the emission intensity of the phosphor of the first light source 11 changes due to aging or temperature characteristics, fluctuations from the chromaticity adjusted at the manufacturing stage can be suppressed.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

  DESCRIPTION OF SYMBOLS 10 Liquid crystal display device, 11 1st light source, 12 2nd light source, 13 Light source drive part, 14 Reference value memory | storage part, 15 Light mixing part, 16 Display control part, 17 Liquid crystal display part, 18 Light quantity detection part, 19 MPU

Claims (3)

The first primary color light out of the three primary colors of red, green, and blue, and the first primary color light that has an intensity depending on the intensity of the first primary color light and the light of at least one primary color of the third primary color are emitted. One light source,
A light amount detector that detects the light amount of the first primary color emitted from the first light source and the light amount of the at least one primary color;
A light source controller that controls the intensity of light emitted by the first light source based on the light amount of the first primary color detected by the light amount detector or the light amount of the at least one primary color;
Based on the light amount of the first primary color detected by the light amount detection unit and the light amount of the at least one primary color, the image displayed by the liquid crystal display unit using the light emitted from the first light source, A liquid crystal display device comprising: a first primary color or an image control unit that adjusts a dynamic range of the at least one primary color. The liquid crystal display device according to claim 1,
The light of the at least one primary color is the light of the second primary color;
A second light source that emits light of a third primary color having an intensity independent of the intensity of the light of the first primary color;
The light of the first primary color and the second primary color emitted from the first light source and the light of the third primary color emitted from the second light source are mixed to generate illumination light, and the illumination light is A light mixing unit that emits light to the liquid crystal display unit;
The light amount detector
Detecting light amounts of the first primary color, the second primary color and the third primary color included in the illumination light;
The light source controller is
Based on the light quantity of the first primary color detected by the light quantity detection unit or the light quantity of the second primary color, the intensity of light emitted from the first light source is controlled and detected by the light quantity detection unit. A liquid crystal display device that controls the intensity of light emitted from the second light source based on the amount of light of the third primary color. The liquid crystal display device according to claim 2,
The first light source emits cyan light by simultaneously emitting blue light and green light as the first primary color light and the second primary color light,
The liquid crystal display device, wherein the second light source emits red light as the light of the third primary color.

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