JP4780123B2 - Liquid crystal display device and head-up display - Google Patents

Description

  The present invention relates to a liquid crystal display device and a head-up display, and more particularly to a field sequential drive liquid crystal display device and a head-up display in which a plurality of light sources emit light sequentially.

  2. Description of the Related Art Conventionally, a field sequential drive liquid crystal display device in which a plurality of light sources emit light sequentially is known (for example, see Patent Document 1).

  Patent Document 1 discloses a liquid crystal display device (head-up display) including two types of light-emitting diode light sources that are complementary to each other and a liquid crystal display device. In Patent Document 1, color display is performed by field sequential driving in which two types of light emitting diode light sources are alternately emitted and a color image is recognized by the afterimage phenomenon of the human eye.

JP 2003-295105 A

  However, in the liquid crystal display device described in Patent Document 1, two types of light-emitting diode light sources are used when inversion driving is performed in which the application direction of the voltage applied to the liquid crystal is alternately switched each time the light emission of the light-emitting diode light source is switched. Since it is (even), when one of the two colors is displayed, the application direction of the voltage applied to the liquid crystal is always the same. Therefore, while the same image is continuously displayed, the voltage in the same application direction is continuously applied to the liquid crystal of the pixel corresponding to the image. As a result, there is a problem that the image sticking of the liquid crystal and the color reproducibility are lowered.

  The present invention has been made to solve the above-described problems, and one object of the present invention is a liquid crystal display capable of suppressing liquid crystal burn-in and color reproducibility deterioration. Is to provide a device.

Means for Solving the Problems and Effects of the Invention

A liquid crystal display device according to a first aspect of the present invention includes a pixel including a liquid crystal, a pixel electrode that applies a voltage to the liquid crystal, and a common electrode, a display unit in which a plurality of pixels are arranged in a matrix, and a light emission color. The pixels are driven in response to light emission in which even light sources emit light sequentially, and the number of light sources is the same as the number of even light sources. When the same video signal is input to the pixel by switching the application direction of the voltage for driving the liquid crystal every several vertical scanning periods, the light emission of the light source of the first color in the application direction of the first voltage first and brightness of the first color displayed on the pixel, the first of the first color displayed on the pixel by the emission of the first-color light sources when the application direction of the second voltage Average the second brightness different from the brightness of It is configured.

In the liquid crystal display device according to the first aspect of the present invention, as described above, a non-video signal is not input to a pixel, but a video signal is input, and the pixel responds to light emission in which even-numbered light sources emit light sequentially. When the same video signal is input to the pixel by switching the application direction of the voltage that drives the liquid crystal every vertical scanning period of the same number as the number of even light sources, the first voltage application direction The first brightness of the first color displayed on the pixel by the light emission of the first color light source and the light emission of the first color light source when the second voltage is applied on the pixel. The second brightness different from the first brightness of the displayed first color is averaged to drive the liquid crystal when the same light source among the even number of light sources emits next time. When the same light source emits light It is possible to prevent the application direction of the voltage applied to the liquid crystal element is always the same. Thereby, it is possible to prevent liquid crystal burn-in and color reproducibility from being lowered. In addition, when a video signal for the same image is input to the pixel, the brightness of the color displayed on the pixel varies depending on the potential difference fluctuation occurring before and after the application direction of the voltage for driving the liquid crystal is switched, but the liquid crystal is driven. Brightness can be averaged by repeatedly switching the voltage application direction.

  In the liquid crystal display device according to the first aspect, preferably, the even number of light sources includes a first light source that emits a first color and a second light source that emits a second color different from the first color. The period in which the first light source and the second light source sequentially emit light once is defined as one unit period, and the application direction of the voltage for driving the liquid crystal is switched for each unit period. With this configuration, after the first light source and the second light source sequentially emit light, the application direction of the voltage for driving the liquid crystal is switched, so that the next time the first light source and the second light source emit light, it is ensured that the pixel The application direction of the voltage applied to the liquid crystal is switched. As a result, it is possible to prevent the application direction of the voltage applied to the liquid crystal from always being the same, so that it is possible to prevent the liquid crystal burn-in and the color reproducibility from being lowered.

  In the liquid crystal display device according to the first aspect, it is preferable that the voltage applied to the common electrode is a constant voltage, and the voltage applied to the pixel electrode is common to the same number of vertical scanning periods as the number of even light sources. The high potential and the low potential are switched with respect to the voltage applied to the electrode. With this configuration, it is possible to perform DCCOM driving in which the voltage applied to the common electrode is constant and the voltage applied to the pixel electrode is switched between a high potential and a low potential. With the configuration according to the first aspect, it is possible to suppress liquid crystal burn-in and color reproducibility from being lowered.

  In the liquid crystal display device according to the first aspect, preferably, the voltage applied to the common electrode is configured to be switched between a high potential and a low potential every vertical scanning period equal to the number of even light sources. ing. With this configuration, ACCOM driving in which the voltage applied to the common electrode and the pixel electrode is switched between a high potential and a low potential can be performed. Therefore, in the ACCOM driving, the configuration according to the first aspect described above is used. Liquid crystal burn-in and color reproducibility can be suppressed from decreasing.

  The liquid crystal display device according to the first aspect is preferably configured such that the application direction of the voltage applied to the liquid crystal is switched for each horizontal line of a plurality of pixels arranged in a matrix. With this configuration, the voltage applied to the liquid crystal can be subjected to line inversion driving with different horizontal lines. Therefore, in the line inversion driving, the liquid crystal burn-in and color can be achieved by the configuration according to the first aspect described above. It can suppress that the reproducibility of this falls.

  In the liquid crystal display device including the first light source and the second light source, the colors emitted from the first light source and the second light source are preferably different colors selected from red, green, and blue. If comprised in this way, a color image can be easily displayed by additive color mixing.

  A head-up display according to a second aspect of the present invention includes the liquid crystal display device according to any one of claims 1 to 6. With such a configuration, it is possible to obtain a head-up display capable of suppressing liquid crystal burn-in and color reproducibility.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the overall configuration of a field sequential liquid crystal display device according to an embodiment of the present invention. 2 and 3 are diagrams showing a detailed configuration of the liquid crystal display device according to the embodiment of the present invention. FIG. 4 is a view for explaining a video output signal of the liquid crystal display device according to the embodiment of the present invention. FIG. 5 is a diagram illustrating a configuration of a pixel according to an embodiment of the present invention. First, the structure of the field sequential liquid crystal display device 100 according to the present embodiment will be described with reference to FIGS. In the present embodiment, a case where the present invention is applied to a field sequential liquid crystal display device 100 which is an example of a liquid crystal display device will be described.

  As shown in FIG. 1, the field sequential liquid crystal display device 100 according to the present embodiment includes a drive unit 1 and a display unit 2. Details will be described below.

  As shown in FIG. 1, the drive unit 1 includes a microcomputer unit 11, an A / D converter 12, a PLL (phase synchronization) circuit 13, a memory 14, an analog driver 15, a SYNC processor 16, and a level conversion circuit. 17, a common electrode driver 18, and an LED control circuit 19.

  The microcomputer unit 11 is connected to all the circuits included in the driving unit 1 and has a function of controlling the operation of the entire driving unit 1. The A / D converter 12 is connected to the memory 14. The A / D converter 12 has a function of converting an analog VIDEO signal (video signal) into a digital signal. The memory 14 has a function of storing RG digital signals. As shown in FIG. 2, the memory 14 includes a memory 14a, a memory 14b, a memory 14c, and a memory 14d. The memory 14a is connected in parallel with the memory 14b. The memory 14c is connected in parallel with the memory 14d. The memories 14a and 14b are configured to receive an R (red) digital VIDEO signal. The memories 14c and 14d are configured to receive a G (green) digital VIDEO signal.

  The PLL circuit 13 is connected to the SYNC processor 16. The PLL circuit 13 has a function of generating a clock necessary for field sequential driving. The SYNC processor 16 has a function of generating a signal for driving a pixel 22 described later. As shown in FIG. 2, the SYNC processor 16 includes a memory timing circuit 16a and an inverting circuit 16b. The inversion circuit 16b has a function of switching the application direction of a voltage for driving the liquid crystal 224 described later between positive (+) and negative (−). Further, the inversion circuit 16b applies a voltage for driving the liquid crystal 224 for each unit period (two vertical scanning periods), with a period (two vertical scanning periods) of LEDs 26a and 26b, which will be described later, sequentially emitting light once as one unit period. It has a function of switching the direction between positive (+) and negative (−). In addition, the memory timing circuit 16a has a function of generating a timing signal for storing the VIDEO signal converted into an RG digital signal in the memory 14 for each RG and generating a timing signal for calling necessary for field sequential driving. .

  As shown in FIG. 3, the inverting circuit 16b includes a DFF circuit (D flip-flop circuit) 16c, a DFF circuit 16d, a DFF circuit 16e, and a synchronous switching circuit 16f. The DFF 16c is connected to the synchronous switching circuit 16f. The DFF circuit 16c is configured such that an internal HD signal (horizontal synchronization signal) is input to the input unit 161c. The DFF circuit 16c is configured such that a RESET signal or a SET signal is input from the synchronous switching circuit 16f. The output unit 162c is configured to output a switching signal to the analog driver 15. The output unit 163c is configured to output an inverted signal of the signal output from the output unit 162c. The input unit 164c is configured to receive this inverted signal.

  The DFF circuit 16d is configured such that an internal VD signal (vertical synchronization signal) is input to the input unit 161d. The output unit 162d is connected to the input unit 161e of the DFF circuit 16e. The input unit 163d is connected to the output unit 162e of the DFF circuit 16e.

  The DFF circuit 16e is configured such that an internal VD signal (vertical synchronization signal) is input to the input unit 163e. The output unit 164e is connected to the synchronization switching circuit 16f. The synchronization switching circuit 16f is configured to receive an internal VD signal (vertical synchronization signal). The DFF circuits 16d and 16e are configured to count two vertical scanning periods (vertical synchronization signals).

  As shown in FIG. 1, the memory 14 is connected to an analog driver 15. The analog driver 15 has a function of converting an RG digital signal into an RG analog signal and supplying the RG analog signal to the display unit 2. As shown in FIG. 2, the analog driver 15 includes a D / A conversion circuit 15a, a D / A conversion circuit 15b, an inverting circuit 15c, and a changeover switch 15d. The D / A conversion circuit 15a is connected to the changeover switch 15d. The D / A conversion circuit 15a has a function of converting an input digital signal into an analog signal and outputting the analog signal as a high-side signal of the VIDEO signal. The inversion circuit 15c is connected to the D / A conversion circuit 15b. The inverting circuit 15c has a function of inverting and outputting the input digital signal. The D / A conversion circuit 15b is connected to the changeover switch 15d. The D / A conversion circuit 15b has a function of converting an input digital signal into an analog signal and outputting it as a Low-side signal. The changeover switch 15d is configured to switch the connection of the D / A conversion circuits 15a and 15b based on a changeover signal output from the inverting circuit 16b of the SYNC processor 16.

  Also, pixel data (VIDEO signal) is output as shown in FIG. 4 in conjunction with the changeover of the changeover switch 15d. Specifically, in this embodiment, the voltage applied to the common electrode 223 (see FIG. 5) described later is a constant voltage (DCCOM). Further, the voltage (VIDEO signal) applied to the pixel electrode 222 (see FIG. 5) is switched between a high potential and a low potential with respect to the voltage applied to the common electrode 223 every two vertical scanning periods. Has been. This VIDEO signal is configured so that the High side and the Low side of the VIDEO signal are output in positive (+) and negative (−) respectively with DCCOM as the center. In the present embodiment, the voltage applied to the common electrode 223 may be a voltage (ACCOM) that switches between a high potential and a low potential every two vertical scanning periods.

  As shown in FIG. 1, the SYNC processor 16 is connected to a memory 14, an analog driver 15, a level conversion circuit 17, and an LED control circuit 19. The level conversion circuit 17 has a function of generating pulses (horizontal / vertical control signals, field sequential drive control signals) for driving the pixels 22. The LED control circuit 19 has a function of controlling light emission and stoppage of light emission of the LED 26 described later in accordance with the timing of field sequential driving. The common electrode driver 18 has a function of determining a voltage to be applied to the common electrode 223 described later and supplying the voltage to the pixel 22.

  As shown in FIG. 1, the display unit 2 drives the substrate 21, the plurality of pixels 22, the H driver 23 and the V driver 24 connected to the plurality of pixels 22, and the H driver 23 and the V driver 24. And an LED 26 (26a and 26b) that emits red (R) and green (G) as a backlight (light source) of the pixel 22. The LED 26 is an example of the “light source” in the present invention. The LED 26a that emits red (R) is an example of the “first light source” in the present invention, and the LED 26b that emits green (G) is an example of the “second light source” in the present invention.

  Further, as shown in FIG. 5, a plurality of signal lines 31 and a plurality of scanning lines 32 are arranged on the substrate 21 so as to be orthogonal to each other. The signal line 31 is connected to the H driver 23, and the scanning line 32 is connected to the V driver 24. Pixels 22 are arranged at positions where the signal lines 31 and the scanning lines 32 intersect. FIG. 5 shows only the configuration for four pixels for the sake of simplicity. Each pixel 22 includes an n-channel transistor 221, a pixel electrode 222, a common electrode 223 disposed opposite to the pixel electrode 222, and a liquid crystal disposed so as to be sandwiched between the pixel electrode 222 and the common electrode 223. 224 and an auxiliary capacitor 225. The drain region D of the n-channel transistor 221 is connected to the signal line 31, and the source region S is connected to the pixel electrode 222 and one electrode of the auxiliary capacitor 225. The gate G of the n-channel transistor 221 is connected to the scanning line 32.

  6 and 7 are diagrams for explaining the operation of the field sequential liquid crystal display device according to the present embodiment. Next, the operation of the field sequential liquid crystal display device 100 according to the present embodiment will be described with reference to FIGS. 1, 2, 6, and 7.

  First, as shown in FIG. 1, an analog VIDEO signal is input to the A / D converter 12, and the analog VIDEO signal is converted into an RG digital signal. A horizontal / vertical synchronization signal is input to the PLL circuit 13. Further, the RG digital signal is stored in the memory 14 in accordance with the timing signal generated by the memory timing circuit 16a (see FIG. 2) of the SYNC processor 16 and stored in the memory 14 for each of the red and green signals. Further, VD (vertical synchronization signal) is counted twice by the inverting circuit 16 b (see FIG. 2) of the SYNC processor 16, and a switching signal is output to the analog driver 15. Thereby, in this embodiment, the application direction of the voltage for driving the liquid crystal 224 is switched between positive (+) and negative (−) every two vertical scanning periods.

  In addition, the SYNC processor 16 generates RG image data write timing and LED 26 light emission timing signals. Based on the timing signal generated by the SYNC processor 16, a horizontal / vertical control signal and a field sequential drive control signal are supplied to the display unit 2 via the level conversion circuit 17. The voltage applied to the common electrode 223 (see FIG. 5) is determined by the common electrode driver 18 and supplied to the display unit 2. The LED control circuit 19 controls the light emission of the LED 26 in accordance with the field sequential drive timing.

  Further, in the present embodiment, as shown in FIG. 6, the application direction of the voltage applied to the liquid crystal 224 is switched for each horizontal line of the plurality of pixels 22 arranged in a matrix. Specifically, a voltage that switches between a high potential and a low potential with respect to the common electrode 223 is applied to the pixel electrode 222 (see FIG. 4) (VIDEO signal), and a voltage that is applied to the liquid crystal 224 for each horizontal line. Different line inversion driving is performed for positive (+) voltage and negative (-) voltage. Note that a constant voltage is applied to the common electrode 223 of the pixel 22.

  Next, the operation of the field sequential liquid crystal display device 100 when an image is displayed on the display unit 2 will be described.

  First, as shown in FIG. 6, the pixel electrodes 222 of the pixels 22 in the odd-numbered rows (first line, third line,...) Of the pixels 22 arranged in a matrix in the vertical scanning period A and the vertical scanning period B. A positive (+) voltage is applied to. Further, a negative (−) voltage is applied to the pixel electrodes 222 of the pixels 22 in the even-numbered rows (second line, fourth line...) Of the pixels 22 arranged in a matrix. On the other hand, the pixel electrodes 222 of the pixels 22 in the odd-numbered rows (first line, third line,...) Of the pixels 22 arranged in a matrix in the vertical scanning period C and the vertical scanning period D are negative. (−) A voltage is applied. Further, a positive (+) voltage is applied to the pixel electrodes 222 of the pixels 22 in the even-numbered rows (second line, fourth line,...) Of the pixels 22 arranged in a matrix.

  Further, as shown in FIG. 4, when a video signal for the same image is input to the pixel 22, the potential difference between the voltage applied to the pixel electrode (VIDEO signal) and the voltage applied to the common electrode 223 (DCCOM). Are configured to be different before and after the application direction of the voltage for driving the liquid crystal 224 is switched. Specifically, the potential difference V1 between DCCOM and the High-side VIDEO signal is different from the potential difference V2 between DCCOM and the Low-side VIDEO signal. Further, the potential differences V1 and V2 vary due to the variation of the VIDEO signal or DCCOM. Thus, before and after the application direction of the voltage for driving the liquid crystal 224 is switched, the brightness of the color displayed on the pixel 22 is different even when a video signal for the same image is input to the pixel 22.

  In FIG. 7, the brightness of red and green displayed on the display unit 2 is illustrated by the thickness of the line, and the thick line indicates that light is emitted brighter than the thin line. The red and green light emission displayed on the display unit 2 is displayed in red on the pixels 22 of the display unit 2 in the vertical scanning period A (red light emission period). The red color displayed on the third line (...) is bright (potential difference V1 shown in FIG. 4), and the red color displayed on the even-numbered rows (second line, fourth line ...) of the pixel 22 is dark ( The potential difference V2) shown in FIG. 4 is displayed.

  Next, in the vertical scanning period B (green light emission period), green is displayed on the pixels 22 of the display unit 2 as in the light emission in the vertical scanning period A (red light emission period). The green color displayed on the first line, the third line... Is bright, and the green color displayed on the even-numbered rows (second line, fourth line...) Of the pixels 22 is dark.

  In the vertical scanning period C (red light emitting period), unlike the light emission in the vertical scanning period A (red light emitting period) and the vertical scanning period B (green light emitting period), the odd-numbered rows (first line, 3) of the pixels 22 are used. The red color displayed on the line (...) is dark, and the red color displayed on the even-numbered lines (second line, fourth line ...) of the pixels 22 is displayed brightly.

  Next, in the vertical scanning period D (green light emitting period), the light is displayed in the odd-numbered rows (first line, third line,...) Of the pixels 22 as in the light emission in the vertical scanning period C (red light emitting period). The green color displayed in the even rows (second line, fourth line,...) Of the pixels 22 is displayed brightly. Thereafter, in the vertical scanning period E (not shown), light emission similar to that in the vertical scanning period A is performed.

  The liquid crystal display device 100 according to the present embodiment can be used for a head-up display 400 as shown in FIG. The liquid crystal display device 100 is attached to a predetermined device so that the display light L1 can be projected onto a display target body 401 (for example, a windshield of an automobile) 401. Specifically, the liquid crystal display device 100 includes a display unit 2 and an LED 26, and the display unit 2 is disposed between the LED 26 and the concave mirror 402. The display light L <b> 1 emitted from the liquid crystal display device 100 is generated when the light L <b> 2 from the LED 26 is incident on the display unit 2.

  Further, the display light L <b> 1 emitted from the liquid crystal display device 100 is reflected by the concave mirror 402 toward the display target 401 and is projected onto the display target 401. The liquid crystal display device 100 and the concave mirror 402 described above are housed in a case 403 having a window portion 403a for transmitting the display light L1. Such an in-vehicle head-up display 400, as shown in FIG. 9, displays information necessary for driving a car (for example, direction indication, inter-vehicle distance, travel distance, various warning information, road information and road guidance information, Such information display is different from natural images and the like, and the number of colors used for display may be small. Since the liquid crystal display device 100 of the present invention is a display device that displays red, green, and additive color mixture of red and green, it can be a liquid crystal display device suitable for such a head-up display 400. .

  In the present embodiment, as described above, the period in which the red LED 26a and the green LED 26b sequentially emit light once is set as one unit period, and the application direction of the voltage for driving the liquid crystal 224 is switched for each unit period. As a result, the application direction of the voltage for driving the liquid crystal 224 is switched after the red LED 26a and the green LED 26b emit light sequentially, so the next time the red LED 26a and the green LED 26b emit light, the liquid crystal of the pixel 22 is surely obtained. The application direction of the voltage applied to 224 is switched. Accordingly, it is possible to prevent the application direction of the voltage applied to the liquid crystal 224 from being always the same, and thus it is possible to suppress the burn-in of the liquid crystal 224 and the deterioration of color reproducibility.

  In the present embodiment, as described above, the voltage applied to the common electrode 223 is a constant voltage, and the voltage applied to the pixel electrode 222 is equal to the voltage applied to the common electrode 223 every two vertical scanning periods. In contrast, the voltage applied to the common electrode 223 is constant and the voltage applied to the pixel electrode 222 with respect to the voltage applied to the common electrode 223 is configured such that the high potential and the low potential are switched. Since it is possible to perform DCCOM driving that switches between a high potential and a low potential, in the DCCOM driving, it is possible to suppress the burn-in of the liquid crystal 224 and the color reproducibility from being lowered by the configuration according to the present embodiment.

  In the present embodiment, as described above, the voltage applied to the common electrode 223 is configured so that the voltage applied to the common electrode 223 is switched between a high potential and a low potential every two vertical scanning periods. Therefore, ACCOM driving that switches between a high potential and a low potential can be performed. Therefore, in the ACCOM driving, it is possible to suppress the burn-in and color reproducibility of the liquid crystal 224 from being reduced by the configuration according to the present embodiment.

  Further, in the present embodiment, as described above, the liquid crystal 224 is configured by switching the application direction of the voltage applied to the liquid crystal 224 for each horizontal line of the plurality of pixels 22 arranged in a matrix. Since the applied voltage can be different for each horizontal line, line inversion driving can be performed, and therefore, in the line inversion driving, the configuration according to the present embodiment prevents the liquid crystal 224 from burning and the color reproducibility from being lowered. Can do.

  In the present embodiment, as described above, the colors emitted from the LEDs 26 (26a and 26b) are made different from each other selected from red, green, and blue. A color image can be displayed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, as an example of the present invention, an example in which two colors of red (R) and green (G) are applied to an even number of light sources has been shown. It is also possible to apply 4 colors other than colors.

  Further, as an example of the light source of the present invention, an example using LEDs that emit red (R) and green (G) light has been shown, but the present invention is not limited to this, and red (R) and blue (B). Or you may comprise by the combination of green (G) and blue (B).

  Further, as an example of the light source of the present invention, an example using LEDs emitting red (R) and green (G) light has been shown, but the present invention is not limited to this, and light of cyan, magenta and yellow colors is shown. An LED that emits light may be used. Thereby, a color image can be easily displayed by subtractive color mixing.

  In this embodiment, an example in which the voltage applied to the pixel electrode of the pixel performs line inversion driving is shown. However, the present invention is not limited thereto, and frame inversion driving, source inversion driving, and dot are not limited thereto. Other inversion driving such as inversion driving may be performed.

  Moreover, although the example using LED was shown as an example of the light source of this invention, this invention is not restricted to this, For example, you may use light-emitting bodies like organic EL.

1 is a block diagram illustrating an overall configuration of a field sequential liquid crystal display device according to an embodiment of the present invention. It is a figure which shows the detailed structure of the liquid crystal display device by one Embodiment of this invention. It is a figure which shows the detailed structure of the liquid crystal display device by one Embodiment of this invention. FIG. 4 is a diagram for explaining a video output signal of a liquid crystal display device according to an embodiment of the present invention. It is a figure which shows the structure of the pixel by one Embodiment of this invention. It is a figure for demonstrating operation | movement of the field sequential liquid crystal display device by one Embodiment of this invention. It is a figure for demonstrating operation | movement of the field sequential liquid crystal display device by one Embodiment of this invention. It is a figure for demonstrating the head-up display using the liquid crystal display device by one Embodiment of this invention. It is a figure for demonstrating the head-up display using the liquid crystal display device by one Embodiment of this invention.

Explanation of symbols

2 Display unit 22 pixels 26 LED (light source)
26a LED (first light source)
26b LED (second light source)
DESCRIPTION OF SYMBOLS 100 Liquid crystal display device 222 Pixel electrode 223 Common electrode 224 Liquid crystal 400 Head-up display

Claims (7)

A pixel including a liquid crystal, a pixel electrode for applying a voltage to the liquid crystal, and a common electrode;
A display unit in which a plurality of the pixels are arranged in a matrix;
With even-numbered light sources with different emission colors,
A non-video signal is not input to the pixel, but a video signal is input.
The pixels are driven according to the light emission of the even light sources sequentially, and the application direction of the voltage for driving the liquid crystal is switched every vertical scanning period equal to the number of the even light sources. When the same video signal is input, the first brightness of the first color displayed on the pixel by the light emission of the light source of the first color when the first voltage is applied, and the second The second brightness different from the first brightness of the first color displayed on the pixel by the light emission of the light source of the first color when the voltage is applied in the direction of the voltage is averaged. A liquid crystal display device comprising: The even number of light sources includes a first light source that emits a first color and a second light source that emits a second color different from the first color;
The period in which the first light source and the second light source sequentially emit light once is defined as one unit period, and the application direction of a voltage for driving the liquid crystal is switched for each unit period. A liquid crystal display device according to 1. The voltage applied to the common electrode is a constant voltage,
The voltage applied to the pixel electrode is configured to be switched between a high potential and a low potential with respect to the voltage applied to the common electrode every number of vertical scanning periods equal to the number of even light sources. The liquid crystal display device according to claim 1 or 2.   The voltage applied to the common electrode is configured to be switched between a high potential and a low potential every number of vertical scanning periods equal to the number of even-numbered light sources. The liquid crystal display device according to item.   5. The liquid crystal according to claim 1, wherein an application direction of a voltage applied to the liquid crystal is switched for each horizontal line of a plurality of pixels arranged in a matrix. 6. Display device.   The liquid crystal display device according to claim 2, wherein colors emitted from the first light source and the second light source are different colors selected from red, green, and blue.   A head-up display comprising the liquid crystal display device according to claim 1.

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