JP5003767B2 - Display device and display method - Google Patents

Description

  The present application provides a display device that performs color display by synchronizing incidence of white light to a display element provided with a plurality of color filters and light control in the display element by display data of each color according to a display image; It relates to the display method.

  With the progress of the so-called information society in recent years, electronic devices represented by personal computers, PDA (Personal Digital Assistants) and the like are widely used. With the spread of such electronic devices, there is a demand for portable devices that can be used both in the office and outdoors, and there is a demand for reduction in size and weight. Liquid crystal display devices are widely used as one of means for achieving such an object. A liquid crystal display device is an indispensable technology for reducing power consumption of a battery-driven portable electronic device as well as reducing the size and weight.

  Liquid crystal display devices are roughly classified into a reflection type and a transmission type. The reflective type is a configuration in which light incident from the front of the liquid crystal panel is reflected on the back of the liquid crystal panel and the image is visually recognized by the reflected light. The transmissive type is from a light source (backlight) provided on the back of the liquid crystal panel. In this configuration, an image is visually recognized with transmitted light. Since the reflective type does not have a constant amount of reflected light depending on environmental conditions and is inferior in visibility, in particular, as a display device such as a personal computer for performing multi-color or full-color display, a transmissive color liquid crystal using a color filter is generally used. A display device is in use.

  Currently, color liquid crystal display devices of a TN (Twisted Nematic) type using a switching element such as a TFT (Thin Film Transistor) are widely used. This TFT-driven TN type liquid crystal display device has a higher display quality than the STN (Super Twisted Nematic) type, but the liquid crystal panel currently has a light transmittance of only about 4%. Requires a high-brightness backlight. For this reason, the power consumption by a backlight will become large. In addition, since color display using a color filter is used, one pixel must be composed of three sub-pixels, and it is difficult to achieve high definition, and the display color purity is not sufficient.

  In order to solve such a problem, the present inventors have developed a field sequential type liquid crystal display device (see, for example, Non-Patent Documents 1 and 2). This field-sequential liquid crystal display device does not require sub-pixels as compared with a color filter-type liquid crystal display device, so that it is possible to easily realize a display with higher accuracy and without using a color filter. In addition, since the emission color of the light source can be used as it is for display, the display color purity is excellent. Furthermore, since the light utilization efficiency is high, there is an advantage that less power consumption is required. However, in order to realize a field-sequential liquid crystal display device, high-speed response of liquid crystal (2 ms or less) is essential.

  Therefore, the present inventors have established a field-sequential type liquid crystal display device or a color filter type liquid crystal display device having excellent advantages as described above in order to increase the response speed by 100 to 1000 as compared with the prior art. We are researching and developing driving of switching devices such as TFTs for liquid crystals such as ferroelectric liquid crystals having spontaneous polarization that can be expected to achieve double the speed response. As shown in FIG. 13, in the ferroelectric liquid crystal, the major axis direction of the liquid crystal molecules changes by the tilt angle θ when a voltage is applied. A liquid crystal panel sandwiching a ferroelectric liquid crystal is sandwiched between two polarizing plates whose polarization axes are orthogonal to each other, and the transmitted light intensity is changed using birefringence due to a change in the major axis direction of liquid crystal molecules.

  FIG. 14 is an example of a time chart showing display control in a conventional field-sequential liquid crystal display device. FIG. 14A is a scanning timing of each line of the liquid crystal panel, and FIG. Indicates the lighting timing of red, green, and blue colors. One frame is divided into three subframes. For example, as shown in FIG. 14B, red is emitted in the first subframe, green is emitted in the second subframe, and the third subframe is emitted. Blue light is emitted in the frame.

  On the other hand, as shown in FIG. 14A, image data writing scanning and erasing scanning are performed on the liquid crystal panel in each of the sub-frames of red, green, and blue. However, the timing is adjusted so that the start timing of the write scan coincides with the start timing of each subframe, and the end timing of the erase scan coincides with the end timing of each subframe, and is required for the write scan and the erase scan. Each time is set to half of each subframe. In writing scanning and erasing scanning, voltages having the same magnitude and different polarities based on the same image data are applied to the liquid crystal panel. The light emission time of each color is equal to the time of the subframe (see, for example, Patent Document 1).

JP 11-119189 A T.A. Yoshihara, et. al. : AM-LCD'99 Digest of Technical Papers, 185 (1999) T.A. Yoshihara, et. al. : SID'00 Digest of Technical Papers, 1176 (2000)

  Field sequential liquid crystal display devices have the advantages of high light utilization efficiency and reduced power consumption. Reduction is required. Such a demand for reduction in power consumption is not limited to a field sequential display device using a liquid crystal display element as a display element, but a field sequential method using another display element such as a digital microdevice (DMD). The same applies to the display device, and also to the color filter type display device.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a display device and a display method capable of reducing power consumption without causing deterioration of display image quality, particularly luminance.

The present application relates to a display device that performs color display by synchronizing white light incident on a display element provided with a plurality of color filters and light control in the display element by display data of each color corresponding to a display image. Detecting means for detecting a gradation level of the maximum brightness of the display data in a predetermined period, and when obtaining the maximum brightness based on a detection result of the detection means, Adjusting the light control amount in the display element so as to maximize the transmittance or the reflectance, and adjusting means for adjusting the intensity of the incident white light according to the adjusted light control amount, the color a plurality of color filters, red, a green and blue, each color of said display data discloses red, green, the display device and a display method wherein the blue and white der Rukoto.

  The present application detects the gradation level of display data corresponding to light incident on the display element, and adjusts the intensity of light incident on the display element and the light control amount in the display element based on the detection result. As a result, it is possible to adjust the intensity of light incident on the display element and the light control amount in the display element according to the display data. For example, for display data that does not require the brightest display, The intensity of incident light and the amount of light control are not adjusted by suppressing the intensity of light incident on the display element and adjusting the light control amount so that the transmittance or reflectance of incident light by the display element is increased. By maintaining the same screen brightness, power consumption can be reduced without degrading the display image quality, in particular, lowering the luminance.

It is a block diagram which shows the circuit structure of the liquid crystal display device (1st, 2nd embodiment) of this invention. It is typical sectional drawing of a liquid crystal panel and a backlight. It is a schematic diagram which shows the structural example of the whole liquid crystal display device. It is a figure which shows the structural example of a LED array. It is a graph which shows the electro-optical response characteristic of the liquid-crystal material used by this invention. It is a time chart which shows the display control in the liquid crystal display device (1st Embodiment) of this invention. It is a figure which shows the example of a division | segmentation of the backlight in the liquid crystal display device (2nd, 3rd embodiment) of this invention. It is a time chart which shows the display control in the liquid crystal display device (2nd Embodiment) of this invention. It is a figure which shows the conversion example of the image data in the liquid crystal display device (3rd Embodiment) of this invention. It is a block diagram which shows the circuit structure of the liquid crystal display device (3rd Embodiment) of this invention. It is a time chart which shows the display control in the liquid crystal display device (3rd Embodiment) of this invention. FIG. 2 is a schematic cross-sectional view of a liquid crystal panel and a backlight in a color filter type liquid crystal display device. It is a figure which shows the alignment state of the liquid crystal molecule in a ferroelectric liquid crystal panel. It is a time chart which shows the display control in the conventional liquid crystal display device. It is a figure for demonstrating the concept of the display device of the conventional field sequential system. It is a figure for demonstrating the concept of the display apparatus of the field sequential system of this invention.

  The present invention will be specifically described with reference to the drawings showing embodiments thereof. Hereinafter, a field-sequential liquid crystal display device in which the display element is a transmissive liquid crystal display element and the light source is an LED array will be described as an example. However, the present invention is limited to the following embodiments. It is not a thing.

(First embodiment)
FIG. 1 is a block diagram showing a circuit configuration of the liquid crystal display device according to the first embodiment, FIG. 2 is a schematic sectional view of a liquid crystal panel and a backlight, and FIG. 3 is a schematic diagram showing an example of the overall configuration of the liquid crystal display device. FIG. 4 is a diagram illustrating a configuration example of an LED array that is a light source of a backlight.

  In FIG. 1, reference numerals 21 and 22 denote a liquid crystal panel and a backlight whose cross-sectional structure is shown in FIG. As shown in FIG. 2, the backlight 22 includes an LED array 7 that emits red, green, and blue light and a light guide and light diffusion plate 6.

  As shown in FIG. 2 and FIG. 3, the liquid crystal panel 21 includes a polarizing film 1, a glass substrate 2, a common electrode 3, a glass substrate 4, and a polarizing film 5 from the upper layer (front surface) side to the lower layer (back surface) side. .. Are formed in this order, and pixel electrodes (pixel electrodes) 40, 40... Arranged in a matrix are formed on the surface of the glass substrate 4 on the common electrode 3 side.

  A driving unit 50 including a data driver 32 and a scan driver 33 is connected between the common electrode 3 and the pixel electrodes 40. The data driver 32 is connected to the TFT 41 via the signal line 42, and the scan driver 33 is connected to the TFT 41 via the scanning line 43. The TFT 41 is on / off controlled by the data driver 32 and the scan driver 33. The individual pixel electrodes 40, 40... Are connected to the TFT 41. Therefore, the transmitted light intensity of each pixel is controlled by a signal from the data driver 32 given via the signal line 42 and the TFT 41.

  An alignment film 12 is disposed on the upper surface of the pixel electrodes 40, 40... On the glass substrate 4, and an alignment film 11 is disposed on the lower surface of the common electrode 3, and a liquid crystal material is filled between the alignment films 11 and 12. A liquid crystal layer 13 is formed. Reference numeral 14 denotes a spacer for maintaining the layer thickness of the liquid crystal layer 13.

  The backlight 22 is located on the lower layer (rear) side of the liquid crystal panel 21, and the LED array 7 is provided in a state where the backlight 22 faces the end face of the light guide and light diffusion plate 6 constituting the light emitting region. As shown in FIG. 4, the LED array 7 emits light of three primary colors, that is, red (R), green (G), and blue (B) on the surface facing the light guide and light diffusion plate 6. The LEDs are arranged sequentially and repeatedly. Then, red, green, and blue LEDs are turned on in the red, green, and blue subframes, respectively. The light guide and light diffusing plate 6 functions as a light emitting region by guiding light emitted from each LED of the LED array 7 to its entire surface and diffusing it to the upper surface.

  The liquid crystal panel 21 and a backlight 22 capable of time division light emission of red, green, and blue are overlapped. The lighting timing and emission color of the backlight 22 are controlled in synchronization with the writing scan / erasure scanning of the image data on the liquid crystal panel 21.

  In FIG. 1, reference numeral 23 denotes a gradation level detection circuit that receives image data PD corresponding to a display image from an external personal computer, for example, and detects the gradation level for each color (red, green, blue). The gradation level detection circuit 23 outputs a gradation level signal GL indicating the gradation level of the image data PD detected for each color (red, green, blue) to the control signal generation circuit 31. The control signal generation circuit 31 receives the synchronization signal SYN from the personal computer and generates various control signals CS necessary for display. Image data PD is output from the image memory unit 30 to the data driver 32 in units of pixels. Based on the image data PD and the control signal CS for changing the polarity of the applied voltage, a voltage having a different polarity and a substantially equal voltage is applied to the liquid crystal panel 21 via the data driver 32 during the data write scan and the data erase scan. Applied each time.

  The reference voltage generation circuit 34 generates reference voltages VR1 and VR2, and outputs the generated reference voltage VR1 to the data driver 32 and the reference voltage VR2 to the scan driver 33, respectively. The data driver 32 outputs a signal to the signal line 42 of the pixel electrode 40 based on the image data PD from the image memory unit 30 and the control signal CS from the control signal generation circuit 31. In synchronization with the output of this signal, the scan driver 33 sequentially scans the scanning lines 43 of the pixel electrodes 40 line by line. The backlight control circuit 35 applies drive voltage to the backlight 22 and causes the LEDs of the red, green, and blue colors included in the LED array 7 of the backlight 22 to emit light in a time-sharing manner.

  A control signal CS generated by the control signal generation circuit 31 based on the gradation level signal GL from the gradation level detection circuit 23 is sent to the backlight control circuit 35 and the data driver 32, and according to the control signal CS. The intensity of light incident on the liquid crystal panel 21 as the display element from the backlight 22 as the light source and the light control amount (switching amount) in the liquid crystal panel 21 are adjusted.

  Next, the operation of the liquid crystal display device according to the present invention will be described. The image data PD for display is input from the personal computer to the gradation level detection circuit 23, the gradation levels in red, green and blue are detected, and the gradation level signal GL indicating the detection result is the control signal generation circuit 31. Sent to. The image memory unit 30 temporarily stores the image data PD and then outputs the image data PD in units of pixels when receiving the control signal CS output from the control signal generation circuit 31. The control signal CS generated by the control signal generation circuit 31 is supplied to the data driver 32, the scan driver 33, the reference voltage generation circuit 34, and the backlight control circuit 35. When receiving the control signal CS, the reference voltage generation circuit 34 generates reference voltages VR1 and VR2, and outputs the generated reference voltage VR1 to the data driver 32 and the reference voltage VR2 to the scan driver 33, respectively.

  When receiving the control signal CS, the data driver 32 outputs a signal to the signal line 42 of the pixel electrode 40 based on the image data PD output from the image memory unit 30. When receiving the control signal CS, the scan driver 33 sequentially scans the scanning lines 43 of the pixel electrodes 40 line by line. The TFT 41 is driven in accordance with the output of the signal from the data driver 32 and the scan of the scan driver 33, a voltage is applied to the pixel electrode 40, and the transmitted light intensity of the pixel is controlled. The transmittance at this time is adjusted based on the gradation level of the image data.

  When the backlight control circuit 35 receives the control signal CS, the backlight control circuit 35 gives the drive voltage adjusted based on the gradation level of the image data to the backlight 22, and the LED array 7 of the backlight 22 has red. , Green and blue LEDs are time-divided to emit light, and red light, green light, and blue light are sequentially emitted over time.

Hereinafter, specific examples will be described. After the TFT substrate having the pixel electrodes 40, 40... (Number of pixels 640 × 480, diagonal 3.2 inches) and the glass substrate 2 having the common electrode 3 are washed, polyimide is applied and baked at 200 ° C. for 1 hour. As a result, a polyimide film of about 200 mm was formed as the alignment films 11 and 12. Furthermore, these alignment films 11 and 12 are rubbed with a cloth made of rayon, these two substrates are overlapped so that the rubbing directions are parallel, and a spacer made of silica having an average particle diameter of 1.8 μm between them. A blank panel was produced by superposing the gaps at 14 while maintaining the gap. A ferroelectric liquid crystal material having a half V-shaped electro-optical response characteristic as shown in FIG. 5 is encapsulated between the alignment films 11 and 12 of this empty panel when the TFT is driven to form a liquid crystal layer 13. The magnitude of spontaneous polarization of the encapsulated liquid crystal material was 8 nC / cm ² . The produced panel was sandwiched between two polarizing films 1 and 5 in a crossed Nicol state to form a liquid crystal panel 21 so that it was in a dark state when no electric field was applied.

  The liquid crystal panel 21 manufactured in this manner and the backlight 22 using the LED array 7 capable of single-color surface emission switching of red, green, and blue as a light source are overlapped, and field sequential is performed according to a drive sequence as described later. Color display by the method was performed.

  Based on the concept of the present invention shown in FIG. 16 described above, the gradation levels of the red, green and blue image data are detected for each subframe, and the backlight 22 to the liquid crystal panel 21 is detected based on the detection result. The intensity of incident light and the transmittance of the liquid crystal panel 21 were adjusted. Specifically, the transmittance is adjusted so that the transmittance of the liquid crystal panel 21 is maximized for image data that requires the maximum amount of transmitted light in each of the red, green, and blue subframes, and the transmittance is adjusted. Depending on the result, the intensity of the incident light was reduced.

  FIG. 6 is a time chart showing display control. FIG. 6A shows scanning timing of each line of the liquid crystal panel 21, and FIG. 6B shows lighting of the red, green, and blue colors of the backlight 22 (LED). Indicates timing. One frame (1/60 s) is divided into three subframes. For example, the red LED is turned on in the first subframe in one frame to perform writing / erasing scanning of red image data. In the second sub-frame, the green LED is turned on to perform writing / erasing scanning of green image data, and in the last third sub-frame, the blue LED is turned on to write / erase scanning of blue image data. I do. That is, image data is scanned twice in each subframe, and its color and intensity are switched every subframe period.

  The voltage applied to the liquid crystal of each pixel in the writing scan and the erasing scan is a voltage having opposite polarities and substantially the same magnitude. As a result, since the sealed liquid crystal material has the characteristics shown in FIG. 5, an image with high transmittance is displayed in the first scan (data writing scan), and the second scan (data In the erasure scan, an image having a lower transmittance (substantially 0) than that in the first scan is obtained. Therefore, an image having no display unevenness can be obtained, and the bias of the applied voltage can be suppressed, so that display burn-in can be prevented.

  As described above, the gradation levels of the red, green, and blue image data are detected for each subframe, and based on the detection result, the intensity of incident light on the liquid crystal panel 21 and the transmittance of the liquid crystal panel 21 are determined. By adjusting, the power consumption of the backlight 22 can be suppressed as compared with the comparative example described below, and the power consumption can be reduced. The display characteristics were the same as in the comparative example, and no image quality degradation was observed.

(Comparative example)
Using the same liquid crystal panel and backlight as in the first embodiment described above, color display was performed according to the drive sequence shown in FIG. 6 as in the first embodiment. However, as shown in FIG. 15 described above, the intensity of incident light in each color on the liquid crystal panel is always constant for each color.

  As a result, most of the display images require higher power consumption than the first embodiment. This is because the light emission intensity of each color of the backlight is constant regardless of the gradation level of the image data, that is, even in a very dark image, the light emission intensity is the same as that of a bright image display, which is wasteful. Is attributed.

(Second Embodiment)
In the second embodiment, the light emission area of the backlight is divided into a plurality of areas, and the incident light intensity and transmittance are adjusted based on the gradation level of the image data according to the present invention for each of the divided areas. The configuration of the liquid crystal panel to be used and the circuit configuration of the liquid crystal display device are the same as those in the first embodiment described above, and a description thereof will be omitted.

  As shown in FIG. 7, the region of the backlight 22 is divided into four small regions 22a to 22d, thereby dividing the light incident region on the liquid crystal panel 21 into four small incident regions. Then, the gradation levels of the red, green, and blue image data are detected for each small region in each subframe, and based on the detection result, the intensity of incident light from the backlight 22 to the liquid crystal panel 21; The transmittance of the liquid crystal panel 21 was adjusted. Specifically, the transmittance of the liquid crystal panel 21 is adjusted so that the transmittance of the image data that requires the maximum amount of transmitted light in each small region in each of the red, green, and blue subframes is maximized, The intensity of incident light was reduced according to the result of adjusting the transmittance.

  FIG. 8 is a time chart showing display control. FIG. 8A shows scanning timing of each line of the liquid crystal panel 21, and FIG. 8B shows lighting of red, green and blue colors of the backlight 22 (LED). Indicates timing. The lighting of the backlight 22 is controlled for every four small areas in one subframe. Then, image data is scanned twice in each subframe, and the intensity of light incident on the liquid crystal panel 21 and the transmittance of the liquid crystal panel 21 are switched for each small area in each subframe. The contents of the two data scans in each subframe are the same as those in the first embodiment shown in FIG. In the second scan of the image data in the second embodiment, the first scan end timing is matched with the second scan start timing.

  As described above, the gradation levels of the red, green, and blue image data are detected for each divided small area in each subframe, and based on the detection result, the intensity of the incident light on the liquid crystal panel 21 and the liquid crystal By adjusting the transmittance of the panel 21, the power consumption of the backlight 22 can be further suppressed as compared with the first embodiment, and the power consumption can be further reduced. The display characteristics are the same as those in the first embodiment and the comparative example, and no image quality deterioration was observed.

(Third embodiment)
In the third embodiment, input red, green, and blue color image data is converted into red, green, blue, and white four-color image data, and the converted four-color image data is used for full color. Display. First, this conversion method will be described.

  9A shows the original red (r), green (g), and blue (b) gradation levels in each frame, and FIG. 9B shows the converted red (r ′) in each frame. ), Green (g ′), blue (b ′), and white (w). In each frame, the gradation levels of red, green, and blue pixel data are compared to detect the lowest gradation level. For example, in the first frame shown in FIG. 9A, the gradation level of the green display data is the lowest. In this case, in the red and blue display sub-frames, the gradation level (r ′ = r−) obtained by subtracting the green gradation level (g) from the red and blue gradation levels (r, b) before comparison. g, b ′ = b−g), red display and blue display are performed.

  In the white display subframe which is a mixed color of red, green and blue, white display (w = g) corresponding to the green gradation level (g) is performed. In the green display sub-frame, green display corresponding to the gradation level (g ′ = g−g) obtained by subtracting the green gradation level (g) from the green gradation level (g) before comparison is also performed. However, since the subtracted gradation level (g ′) is 0, this is generally “black” display. With such a conversion process, the maximum amount of transmitted light in each subframe becomes smaller than when such a conversion process is not performed, so that the power consumption can be further reduced.

  FIG. 10 is a block diagram showing a circuit configuration of the liquid crystal display device according to the third embodiment. In FIG. 10, the same or similar members as those in FIG. The configuration of the liquid crystal panel 21 is the same as that of the first embodiment, and the backlight 22 is divided into four small regions as in the second embodiment. In the white subframe, the red, green, and blue LEDs in the LED array 7 are turned on simultaneously.

  In FIG. 10, reference numeral 24 denotes an image data conversion circuit 24 that converts three-color image data PD input from an external personal computer, for example, into four-color image data PD ′ for display according to the above-described method. The data conversion circuit 24 outputs the converted image data PD ′ to the gradation level detection circuit 23. The gradation level detection circuit 23 outputs a gradation level signal GL representing the gradation level of the image data PD ′ detected for each color (red, green, blue, white) to the control signal generation circuit 31. Then, the control signal CS generated by the control signal generation circuit 31 based on the gradation level signal GL from the gradation level detection circuit 23 is sent to the backlight control circuit 35 and the data driver 32, and the control signal CS is sent to the control signal CS. Accordingly, the intensity of light incident on the liquid crystal panel 21 from the backlight 22 and the transmittance of the liquid crystal panel 21 are adjusted for each small region in each subframe.

  Note that the configuration and operation of other members such as the data driver 32, the scan driver 33, and the reference voltage generation circuit 34 only change the image data PD to the converted image data PD ′, and are basically the same as those in the first embodiment. The description is omitted here.

  FIG. 11 is a time chart showing display control. FIG. 11A shows scanning timing of each line of the liquid crystal panel 21, and FIG. 11B shows red, green, blue, and white colors of the backlight 22 (LED). The lighting timing of is shown. The lighting of the backlight 22 is controlled for every four small areas in one subframe. Then, image data is scanned twice in each subframe, and the intensity of light incident on the liquid crystal panel 21 and the transmittance of the liquid crystal panel 21 are switched for each small area in each subframe.

  The contents of the two data scans in each subframe and the timing of each data scan are the same as those in the second embodiment shown in FIG.

  As described above, after converting red, green, and blue image data into red, green, blue, and white image data, the gradation level of the converted image data is set for each divided small area in each subframe. By detecting and adjusting the intensity of the incident light to the liquid crystal panel 21 and the transmittance of the liquid crystal panel 21 based on the detection result, the consumption of the backlight 22 compared to the first and second embodiments. Electric power can be further suppressed, and further reduction of power consumption can be realized. The display characteristics are the same as those in the first and second embodiments and the comparative example, and no image quality deterioration was observed.

  In each of the above-described embodiments, a field-sequential liquid crystal display device using a transmissive liquid crystal display element as a display element has been described as an example. However, other display elements such as a digital micromirror device (DMD), etc. Of course, the present invention can be similarly applied to other display devices using the. When this DMD is used, the intensity of incident light on the display element and the reflectance at the display element are adjusted based on the detected gradation level of the display data. Further, although the light source used is an LED light source, it is not particularly limited to an LED light source as long as it is a switchable light source such as an EL.

  Further, it goes without saying that the same effect can be obtained in a color display device using a color filter. This is because, in the color filter system, if the red, green, and blue emission colors in the first and second embodiments are set to white and a color filter is provided on the liquid crystal panel, the present invention can be similarly applied. It is.

  FIG. 12 is a schematic cross-sectional view of a liquid crystal panel and a backlight in a liquid crystal display device using a color filter. In FIG. 12, the same parts as those in FIG. Three color filters 60, 60,... Of three primary colors (R, G, B) are provided below the respective pixel electrodes (pixel electrodes) 40, 40,. Alternatively, a color filter is provided between the common electrode 3 and the glass substrate 2 facing each pixel electrode (pixel electrode) 40, 40. The backlight 22 includes a white light source 70 that emits white light and a light guide and light diffusion plate 6.

  In such a color filter type display device, the intensity of incident light on the display element based on the gradation level of the display data in each subframe in the field-sequential system and the light control amount in the display element. By performing the same adjustment as the above adjustment in each frame, it is possible to reduce the power consumption without causing deterioration of the display image quality (brightness).

(Supplementary note 1) Field sequential method in which display is performed by synchronizing sequential switching of light of a plurality of colors incident on a display element and light control on the display element by display data of each color corresponding to a display image In the display device, the detection means for detecting the gradation level of the display data, and the intensity of light incident on the display element and the light control amount in the display element are adjusted based on the detection result of the detection means And a display unit.
(Appendix 2) The detection of the gradation level by the detection means and the adjustment of the light intensity and the light control amount by the adjustment means are performed for each color light incident on the display element. The display device according to appendix 1.
(Additional remark 3) The said detection means detects the gradation level of the maximum brightness of the display data in a predetermined period, and when the said maximum brightness is obtained, the said adjustment means transmits the incident light in the said display element. The light control amount in the display element is adjusted so that the reflectance or the reflectance is maximized, and the intensity of incident light is adjusted in accordance with the adjusted light control amount. Or the display apparatus of 2.
(Supplementary Note 4) The supplementary note is characterized in that, when obtaining brightness at a gradation level other than the gradation level having the maximum brightness, the adjustment means adjusts a light control amount in the display element. 3. The display device according to 3.
(Supplementary Note 5) The intensity of light incident on the display element after the adjustment of the light intensity and the light control amount by the adjusting means is the intensity of the light incident on the display element when the adjustment is not performed. The display device according to any one of appendices 1 to 4, wherein the display device is smaller in strength.
(Additional remark 6) The incident area of the light incident on the display element is divided, and the gradation level is detected by the detection means, and the light intensity and the light control amount are adjusted by the adjustment means. The display device according to any one of appendices 1 to 5, wherein the display device is performed for each incident region.
(Supplementary note 7) The display device according to any one of supplementary notes 1 to 6, wherein the display element is a liquid crystal display element.
(Additional remark 8) The liquid crystal material used for the said liquid crystal display element has spontaneous polarization, The display apparatus of Additional remark 7 characterized by the above-mentioned.
(Supplementary note 9) The display device according to any one of supplementary notes 1 to 6, wherein the display element is a digital microdevice.
(Supplementary note 10) The display device according to any one of supplementary notes 1 to 9, wherein the light of a plurality of colors incident on the display element is red light, green light, and blue light.
(Supplementary note 11) The display device according to any one of supplementary notes 1 to 9, wherein light of a plurality of colors incident on the display element is red light, green light, blue light, and white light.
(Additional remark 12) It is provided with the conversion means which converts red, green, and blue image data into red, green, blue, and white image data, The said detection means has the gradation level of the image data obtained by this conversion means The display device according to appendix 11, wherein the display device is detected.
(Additional remark 13) Display apparatus which performs color display by synchronizing incidence of white light to a display element provided with a plurality of color filters and light control on the display element by display data of each color corresponding to a display image And detecting the gray level of the display data, and adjusting the intensity of white light incident on the display element and the light control amount in the display element based on the detection result of the detection means And a display device.
(Supplementary Note 14) Field sequential display is performed by synchronizing the sequential switching of the light of a plurality of colors incident on the display element and the light control on the display element by the display data of each color corresponding to the display image. In the display method, the gradation level of the display data is detected, and the intensity of light incident on the display element and the light control amount in the display element are adjusted based on the detection result of the gradation level. A display method characterized by.
(Supplementary Note 15) A display method for performing color display by synchronizing white light incident on a display element provided with a plurality of color filters and light control on the display element by display data of each color corresponding to a display image And detecting the gradation level of the display data and adjusting the intensity of white light incident on the display element and the light control amount in the display element based on the detection result of the gradation level. Display method.

3 Common electrode 7 LED array 21 Liquid crystal panel 22 Backlight 23 Gradation level detection circuit 24 Image data conversion circuit 31 Control signal generation circuit 32 Data driver 35 Backlight control circuit 60 Color filter 70 White light source

Claims (5)

In a display device for performing color display by synchronizing white light incident on a display element provided with a plurality of color filters and light control in the display element by display data of each color according to a display image for a predetermined period Detecting means for detecting the gradation level of the maximum brightness of the display data in the display, and when obtaining the maximum brightness based on the detection result of the detection means, the transmittance of incident light in the display element or Adjusting the light control amount in the display element so as to maximize the reflectance, and adjusting means for adjusting the intensity of the incident white light according to the adjusted light control amount, and a plurality of the color filters the color red is green and blue, each color of said display data, a display device for red, green, characterized in blue and white der Rukoto.   2. The light-emitting device according to claim 1, wherein when the brightness at a gradation level other than the maximum brightness gradation level is obtained, the adjustment unit adjusts a light control amount in the display element. Display device.   The intensity of light incident on the display element after adjusting the light intensity and the light control amount by the adjusting means is smaller than the intensity of light incident on the display element when the adjustment is not performed. The display device according to claim 1 or 2.   The incident area of light incident on the display element is divided, and the detection of the gradation level by the detecting means and the adjustment of the light intensity and the light control amount by the adjusting means are performed for each incident area. The display device according to claim 1, wherein the display device is performed. Red, red corresponding to the white light incident to the display image of the display device provided with color filters of green and blue, green, and is synchronized with the light control in the display device by the blue and white color display data a display method for performing color display, and detects the maximum brightness gradation level of the display data in a predetermined period, based on the detection result of the grayscale level, when obtaining the brightness of the maximum, Adjusting the light control amount in the display element so that the transmittance or reflectance of the incident light in the display element is maximized, and adjusting the intensity of the incident white light according to the adjusted light control amount. Characteristic display method.

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