JP2005292434A - Field sequential liquid crystal display - Google Patents

Abstract

A field sequential liquid crystal display device capable of displaying a high-quality color image without color shift or flickering is provided.
Three fields obtained by dividing one frame into three are divided into two periods, and each odd-numbered pixel of a liquid crystal display element is divided into first divided periods t _1a , t _2a , and t _3a for each field. Write unit color image data of one of red, green, and blue to the pixels in the row, and emit illumination light of the color corresponding to the unit color image data from the surface light source to correspond to each odd pixel row A unit color image of one color is displayed on the portion to be reset, reset data is written to the pixels of each even-numbered pixel row, the previous writing state of these pixels is reset, and the second divided period t for each field _{1b, t 2b,} the t _3b, to reset the previous write state of these pixels write the reset data to the odd-numbered pixel in each pixel row, red even-numbered pixels in each pixel row, green, blue Unit color image data of one of the colors , The illumination light of the color corresponding to the unit color image data is emitted from the surface light source, and the unit color image of one color is displayed in the portion corresponding to each previous even-numbered pixel row.
[Selection] Figure 2

Description

  The present invention relates to a field sequential liquid crystal display device.

  A field sequential liquid crystal display device displays a color image using a liquid crystal display element that does not include a color filter, and is a liquid crystal display element having a display area in which a plurality of pixels are arranged in a matrix in a row direction and a column direction. By sequentially writing unit color image data of three colors of red, green, and blue to the pixels of each pixel row and sequentially emitting illumination light of a color corresponding to the unit color image data from the surface light source, the liquid crystal display element The three unit color images of red, green, and blue are displayed in order, and a full color image is displayed by visual mixing of the respective colors.

In the field sequential liquid crystal display device, the red, the pixels of all the rows of the liquid crystal display element are divided into the red, red, and red for each of three fields obtained by dividing one frame for displaying one color image having a plurality of colors. The unit color image data of one color of green and blue is written, and illumination light of a color corresponding to the unit color image data is emitted from the surface light source (see Patent Document 1).
JP 2002-221700 A

  By the way, the field sequential liquid crystal display device displays a color image by changing the display color of each pixel of the liquid crystal display element to red, green, and blue every three fields obtained by dividing one frame into three fields. Since the response speed of the liquid crystal is not sufficiently high, the unit color in which the transmittance of each pixel of the liquid crystal display element is written before the liquid crystal sufficiently responds to the writing of the unit color image data. Before the value corresponding to the image data is reached, illumination light of a color corresponding to the unit color image data is emitted from the surface light source, and the brightness of the display color of each field becomes different from the unit color image data. Thus, color misregistration occurs in the color image displayed by the three unit color images of the three fields.

  Therefore, in the field sequential liquid crystal display device, before the unit color image data is written, the reset data is written to the pixels in each pixel row of the liquid crystal display element to reset the previous writing state, and then the pixels in each pixel row are reset. By writing the unit color image data, it is desired that the response of the liquid crystal to the writing of the unit color image data is made faster so that the brightness of the display color of each field becomes the brightness corresponding to the unit color image data. Yes.

  However, the writing state is reset in a conventional field sequential liquid crystal display device that writes unit color image data of one of red, green, and blue to pixels in all rows of the liquid crystal display elements for each field. In each field, first, reset data is written to pixels in all rows of the liquid crystal display elements, and the liquid crystal molecules of these pixels are aligned in a state where the previous writing state is reset in response to the writing of the reset data. The unit color image data must be written after waiting for this.

  Therefore, in the conventional field sequential liquid crystal display device, for each field, the reset data is written to the pixels of all rows and the response period of the liquid crystal, the unit color image data is written to the pixels of all rows and the liquid crystal is written. The response period and the display period of the unit color image due to the lighting of the surface light source must be ensured. For this purpose, the frame frequency must be lowered, which causes display flicker.

  An object of the present invention is to provide a field sequential liquid crystal display device capable of displaying a high-quality color image without color shift or flicker.

  The field sequential liquid crystal display device of the present invention has a display area in which a plurality of pixels are arranged in a matrix in the row direction and the column direction, and unit color image data of three colors of red, green, and blue is stored in each pixel row. A liquid crystal display element that is sequentially written in pixels and displays an image of each unit color according to these image data, and is arranged on the opposite side of the liquid crystal display element from the observation side, and is in three colors of red, green, and blue A surface light source that selectively emits the illumination light toward the liquid crystal display element and three fields divided into three frames for displaying one color image composed of a plurality of colors are divided into two periods, respectively. In the first division period for each of the three fields, the pixels in each pixel row of one pixel row group out of two pixel row groups obtained by grouping each pixel row of the liquid crystal display element into approximately half of each other. To the red, The unit color image data of one color of blue is written, and the illumination light of the color corresponding to the unit color image data is emitted from the surface light source to the portion corresponding to each pixel row of the one pixel row group The unit color image of one color is displayed, reset data is written in the pixels of each pixel row of the other pixel row group of the liquid crystal display element to reset the previous writing state of these pixels, and the three fields In each second divided period, reset data is written to the pixels of each pixel row of the one pixel row group to reset the previous writing state of these pixels, and each pixel row of the other pixel row group is reset. The unit color image data of one color of red, green, and blue is written to the pixels of the pixel, and the illumination light of the color corresponding to the unit color image data is emitted from the surface light source to each of the other pixel row groups Pair to pixel row Characterized by comprising a display control means for displaying the unit color images of the one color in a portion.

  In this field sequential liquid crystal display device, it is desirable that one pixel row group of the liquid crystal display element is an odd-numbered pixel row group and the other pixel row group is an even-numbered pixel row group.

  In that case, the display control means selects the pixel rows of the liquid crystal display element in order and supplies a scanning signal, and selects the odd-numbered pixel rows and the even-numbered pixel rows of the liquid crystal display elements. Correspondingly, the unit color image data signal and the reset data signal are alternately supplied to each pixel column, and the unit color image data and the reset data are supplied to the pixels of the odd-numbered pixel rows and the pixels of the even-numbered pixel rows. It is preferable to have a configuration including data writing means for alternately writing.

  In addition, the display control unit is configured so that, for each of the three fields, the pixels in one pixel row group of the liquid crystal display element and the pixels in each pixel row of the other pixel row group have different colors. The unit color image data is preferably written.

  In the field sequential liquid crystal display device of the present invention, three fields obtained by dividing one frame into three are divided into two periods, respectively, and each pixel row of the liquid crystal display element is substantially omitted during the first divided period for each of the three fields. Of the two pixel row groups divided into groups of half, unit color image data of one color of red, green, and blue is written to the pixels of each pixel row of one pixel row group, and the unit color image data Corresponding color illumination light is emitted from a surface light source, the unit color image of one color is displayed in a portion corresponding to each pixel row of the one pixel row group, and the other pixel row group of the liquid crystal display element is displayed. Reset data is written to the pixels in each pixel row to reset the previous writing state of these pixels, and each image in the one pixel row group is reset in the second divided period for each of the three fields. Reset data is written to the pixels in the row to reset the previous writing state of these pixels, and the unit color image of one color of red, green, and blue is applied to the pixels in each pixel row of the other pixel row group Data is written, and illumination light of a color corresponding to the unit color image data is emitted from the surface light source, and the unit color image of one color is displayed in a portion corresponding to each pixel row of the other pixel row group. Therefore, the brightness of the display color of each field is set to the brightness corresponding to the unit color image data to eliminate the color shift of the color image, and the frame frequency is sufficiently increased to eliminate the display flicker. be able to.

  Therefore, according to this field sequential liquid crystal display device, it is possible to display a high-quality color image without color shift or flicker.

  In this field sequential liquid crystal display device, it is preferable that one pixel row group of the liquid crystal display element is an odd-numbered pixel row group, and the other pixel row group is an even-numbered pixel row group. Thus, the display of the liquid crystal display element in the first divided period and the second divided period for each field is written in the unit color image display unit and the reset data corresponding to the pixel row in which the unit color image data is written. A non-display portion corresponding to the inserted pixel row is displayed alternately in each row, and a unit color image with good image quality in which the unit color image display portion and the non-display portion are arranged in a well-balanced manner is displayed. Can do.

  In that case, the display control means selects the pixel rows of the liquid crystal display element in order and supplies a scanning signal, and selects the odd-numbered pixel rows and the even-numbered pixel rows of the liquid crystal display elements. Correspondingly, the unit color image data signal and the reset data signal are alternately supplied to each pixel column, and the unit color image data and the reset data are supplied to the pixels of the odd-numbered pixel rows and the pixels of the even-numbered pixel rows. Are preferably provided with data writing means for alternately writing the unit color image data in the first divided period and the second divided period for each field. The reset data can be written within the same period, and the frame frequency can be further increased.

  In addition, the display control unit is configured so that, for each of the three fields, the pixels in one pixel row group of the liquid crystal display element and the pixels in each pixel row of the other pixel row group have different colors. It is preferable that the unit color image data is written, and by doing so, the visual mixing of each color of the unit color image of three colors of red, green, and blue for each of the three fields is excellent. In addition, a higher quality color image can be displayed.

  1 and 2 show an embodiment of the present invention, and FIG. 1 is an exploded perspective view of a field sequential liquid crystal display device.

  This field sequential liquid crystal display device has a display area A in which a plurality of pixels (not shown) are arranged in a plurality of rows as shown in FIG. A liquid crystal display element 1 which is sequentially written in a plurality of pixels and displays an image corresponding to the image data, a surface light source 6 disposed on the opposite side of the observation side of the liquid crystal display element 1, and the liquid crystal display There is provided display control means 12 for writing unit color image data of the three colors red, green and blue into the element 1 and emitting illumination light of a color corresponding to the unit color image data from the surface light source 6.

  The liquid crystal display element 1 is an active matrix liquid crystal display element having, for example, a TFT (thin film transistor) as an active element, and the internal structure thereof is not shown, but a pair of transparent substrates 2 joined through a frame-shaped sealing material 2 3, a plurality of transparent pixel electrodes arranged in a matrix in the row direction and the column direction on one substrate, for example, a surface of the incident side substrate 2 facing the observation side substrate 3, and connected to these pixel electrodes, respectively. A plurality of TFTs, a plurality of gate wirings for supplying gate signals to the TFTs in each row, and a plurality of gate wirings for supplying gate signals to the TFTs in each column, respectively. A single film that forms a plurality of pixels arranged in a matrix on the surface facing the incident side substrate 2 by regions facing the pixel electrodes, respectively. Transparent counter electrodes are provided for, has a structure in which the liquid crystal layer is provided in a region surrounded by the sealing material between the substrates 2 and 3.

  The incident-side substrate 2 has driver mounting portions 2a and 2b extending outward from the observation-side substrate 3 at one end edge in the row direction and one end edge in the column direction, and the plurality of gates The wiring is connected to the gate side driver 4 mounted on the driver mounting portion 2a in the row direction, and the plurality of data wirings are connected to the data side driver 5 mounted on the driver mounting portion 2b in the column direction. The electrode is connected to the gate driver 4 and the data driver 5 via a cross connection portion provided at a substrate bonding portion by the sealing material and a counter electrode connection wiring formed on one or both of the driver mounting portions 2a and 2b. Are connected to one or both of the reference potentials.

  The liquid crystal display element 1 is, for example, a TN (twisted nematic) type in which liquid crystal molecules are twisted in a state of being tilted with respect to the surfaces of the substrates 2 and 3, or a liquid crystal molecule having a molecular long axis in one direction. Are non-twisted and homogeneously oriented, and are omitted in the figure, but on the outer surfaces of the pair of substrates 2 and 3, the incident side polarizing plate and the display side polarizing plate are respectively The liquid crystal display element of the normally white mode is arranged so that its transmission axis is directed in a predetermined direction.

  The surface light source 6 is composed of a plate-like transparent member such as an acrylic resin plate having an area facing the entire display area A of the liquid crystal display element 1, and is formed on one end surface of the transparent member so that light is incident thereon. The incident end face 8, the exit face 9 that emits the light that is incident from the incident end face 8 and guided through the transparent member, and the light that enters the transparent member from the incident end face 8 enters the exit face 9. A light guide plate 7 having a reflective surface 10 that reflects toward the light source, and an incident end face 8 of the light guide plate 7 are disposed so as to face each other, and light of three colors of red, green, and blue is selectively directed toward the incident end face 8. And a light emitting element 11 that emits light.

  Although omitted in FIG. 1, the reflective surface 10 of the light guide plate 7 has a plurality of groove portions having a width of about 10 to 30 μm along the direction parallel to the incident end surface 8 over the entire area of 50 to 100 μm. The light incident from the incident end face 8 is formed at a certain pitch, and the interface between the exit surface 9 and the outside air (air layer) and the interface between the flat surface and the outside air between the plurality of grooves of the reflecting surface 10. The light guide plate 7 is guided in its length direction while being totally reflected, and is totally reflected in the direction in which the angle with respect to the normal line of the exit surface 9 becomes smaller at the interface between the plurality of grooves of the reflective surface 10 and the outside air, The light is emitted toward the liquid crystal display element 1 from the entire emission surface 9 with a uniform luminance distribution.

  The light emitting element 11 is a solid light emitting element having a red LED (light emitting diode) that emits red light, a green LED that emits green light, and a blue LED that emits blue light, although the internal structure thereof is not shown. Yes, the LEDs of the three colors red, green, and blue are selectively driven to light, and light of the three colors red, green, and blue is selectively emitted toward the incident end face 8 of the light guide plate 7.

  That is, the surface light source 6 selectively emits illumination light of three colors of red, green, and blue from the light emitting element 11, guides the light by the light guide plate 7, and the liquid crystal display element from the emission surface 9. The light is emitted toward 1.

  In this embodiment, the light emitting element of the surface light source 6 is a solid light emitting element 11 including LEDs of three colors of red, green, and blue, but is disposed to face the incident end face 8 of the light guide plate 7. The light emitting element to be used may be three cold cathode tubes that respectively emit light of red, green, and blue colors.

  Further, the display control means 12 divides three fields obtained by dividing one frame for displaying one color image composed of a plurality of colors into two periods, respectively, and divides the first field for each of the three fields. Of the two pixel row groups in which the pixel rows of the liquid crystal display element 1 are grouped into approximately half of the pixel rows in the divided period, the pixels in each pixel row of one pixel row group are selected from the red, green, and blue pixels. One unit color image data is written, illumination light of a color corresponding to the unit color image data is emitted from the surface light source 6, and the one color row data is applied to a portion corresponding to each pixel row of the one pixel row group. A unit color image is displayed, reset data is written to the pixels in each pixel row of the other pixel row group of the liquid crystal display element 1 to reset the previous writing state of these pixels, and the third field for each of the three fields. In the divided period, reset data is written to the pixels in each pixel row of the one pixel row group to reset the previous writing state of these pixels, and the pixels in each pixel row of the other pixel row group are The unit color image data of one color of red, green, and blue is written, and illumination light of a color corresponding to the unit color image data is emitted from the surface light source 6 to each pixel row of the other pixel row group. The unit color image of one color is displayed in the corresponding part.

  In this embodiment, one pixel row group of the liquid crystal display element 1 is defined as an odd-numbered pixel row group of the first row, third row, fifth row,..., And the other pixel row group is defined as second row, second row. Although the specific configuration of the display control unit 12 is not shown, the pixel control unit 12 sequentially selects each pixel row of the liquid crystal display element 1 one by one. A unit color image data signal and a reset data signal are alternately supplied to each pixel column in response to the selection of the odd-numbered pixel row and the even-numbered pixel row of the liquid crystal display element 1 and the means for supplying the scanning signal. Data writing means for alternately writing unit color image data and reset data to the pixels of the odd-numbered pixel rows and the pixels of the even-numbered pixel rows, and after the writing of the unit color image data and the reset data The liquid crystal molecules of each pixel of the liquid crystal display element 1 are The color corresponding to the unit color image data written in the liquid crystal display element 1 after elapse of the liquid crystal response time for alignment in the display alignment state corresponding to the unit color image data and the reset alignment state corresponding to the reset data. A surface light source surface driving unit that emits illumination light from the surface light source 6 for a predetermined display time is provided.

  In other words, in this embodiment, the display control means 12 sequentially selects each pixel row of the liquid crystal display element 1 one by one in the first divided period for each of the three fields, so that the odd number and the even number. After writing the unit color image data of one color of red, green, and blue to the pixels of any one of the pixel rows, reset data to the pixels of the other pixel rows, and after the liquid crystal response time has elapsed, Illumination light of a color corresponding to the unit color image data written in the liquid crystal display element 1 is emitted from the surface light source 6 and the unit color image of one color is displayed in a portion corresponding to the one pixel row. In the second division period for each of the three fields, each pixel row of the liquid crystal display element 1 is sequentially selected, and one pixel unit of red, green, and blue is selected for each pixel of the other pixel row. The color image data is reset to the pixels of the one pixel row. After the liquid crystal response time has elapsed, the illumination light of the color corresponding to the unit color image data written in the liquid crystal display element 1 is emitted from the surface light source 6 to correspond to the other pixel row. The unit color image of one color is displayed on the portion to be displayed.

  The unit color image data of each color of red, green, and blue is the luminance data of each color of red, green, and blue corresponding to the color image information supplied from the external circuit (not shown) to the display control unit 12, the reset The data is sufficiently high voltage data for aligning the liquid crystal molecules of the liquid crystal display element 1 substantially perpendicular to the planes of the substrates 2 and 3, and the liquid crystal display element 1 is in a normally white mode as described above. Therefore, each pixel in which the reset data is written, that is, each pixel in which liquid crystal molecules are substantially vertically raised and oriented is in a black non-display state.

FIG. 2 is a display sequence diagram of one field of the field sequential liquid crystal display device, where t _1a and t _1b are first and second divided periods obtained by dividing the first field of one frame into two, t _2a , t _2b is a first and second divided period obtained by dividing the second field of the one frame into two, and t _3a and t _3b are first and second divided periods obtained by dividing the third field of the one frame into two. .

In this embodiment, one frame is set to 40 msec, the first to third fields are set to about 13.34 msec, and the divided periods t _1a , t _1b , t _2a , t _2b , t _3a , and t _3b are set to about It is set to 6.67 msec.

The display sequence of one field of the field sequential liquid crystal display device will be described. In the field sequential liquid crystal display device of this embodiment, first, at the initial _stage of the first divided period t _1a of the first field, the liquid crystal display element 1 Each pixel row is sequentially selected, red unit color image data is written to the pixels of the odd-numbered pixel rows, and reset data is written to the pixels of the even-numbered pixel rows, and then each pixel of the liquid crystal display element 1 is written. After the liquid crystal molecules have passed the liquid crystal response time in which the liquid crystal molecules are aligned in the display alignment state corresponding to the unit color image data and the reset alignment state corresponding to the reset data, red illumination light is emitted from the surface light source 6 and the odd number A red unit color image is displayed in a portion corresponding to each pixel row. At this time, the portion corresponding to each even-numbered pixel row in which the reset data is written is in a non-display state (black).

Next, at the initial _stage of the second division period _t1b of the first field, each pixel row of the liquid crystal display element 1 is sequentially selected, and green unit color image data is supplied to the pixels of each even-numbered pixel row. The reset data is written to the pixels in each odd-numbered pixel row, and after the liquid crystal response time has elapsed, the green illumination light is emitted from the surface light source 6 to the portions corresponding to the even-numbered pixel rows. Display the green unit color image. At this time, the portion corresponding to each odd-numbered pixel row in which the reset data is written is in a non-display state (black).

Next, in the initial _stage of the first division period _t2a of the second field, the pixel rows of the liquid crystal display element 1 are sequentially selected, and the blue unit color image data is supplied to the pixels of the odd-numbered pixel rows. Write reset data to the pixels in each even-numbered pixel row, and then, after the liquid crystal response time has elapsed, blue illumination light is emitted from the surface light source 6 and blue is applied to the portions corresponding to the odd-numbered pixel rows. The unit color image is displayed. At this time, the portion corresponding to each even-numbered pixel row in which the reset data is written is in a non-display state (black).

Next, in the initial _stage of the second division period _t2b of the second field, each pixel row of the liquid crystal display element 1 is sequentially selected, and red unit color image data is supplied to the pixels of each even-numbered pixel row. The reset data is written to the pixels in each odd-numbered pixel row, and after the liquid crystal response time has elapsed, red illumination light is emitted from the surface light source 6 to the portions corresponding to the even-numbered pixel rows. A red unit color image is displayed. At this time, the portion corresponding to each odd-numbered pixel row in which the reset data is written is in a non-display state (black).

Next, at the beginning of the first division period _t3a of the third field, the pixel rows of the liquid crystal display element 1 are sequentially selected, and the green unit color image data is supplied to the pixels of the odd-numbered pixel rows. Write reset data to the pixels in each even-numbered pixel row, and then after the liquid crystal response time has elapsed, green illumination light is emitted from the surface light source 6 and green in the portion corresponding to each odd-numbered pixel row. The unit color image is displayed. At this time, the portion corresponding to each even-numbered pixel row in which the reset data is written is in a non-display state (black).

Next, at the initial _stage of the second division period _t3b of the third field, the pixel rows of the liquid crystal display element 1 are sequentially selected, and the blue unit color image data is supplied to the pixels of the even-numbered pixel rows. The reset data is written to the pixels of each odd-numbered pixel row, and after the liquid crystal response time has elapsed, blue illumination light is emitted from the surface light source 6 to the portions corresponding to the even-numbered pixel rows. A blue unit color image is displayed. At this time, the portion corresponding to each odd-numbered pixel row in which the reset data is written is in a non-display state (black).

The following is a repetition of the display sequence, and is displayed in a portion corresponding to each odd-numbered pixel row in the first divided period t _1a , t _2a , t _3a of the first to third fields for each frame. Unit color images of three colors of red, blue, and green, and green displayed in portions corresponding to even-numbered pixel rows in the second divided periods t _1b , t _2b , and t _3b of the first to third fields A full-color image is displayed with unit color images of three colors, red and blue.

  As described above, the field sequential liquid crystal display device divides three fields obtained by dividing one frame into three, respectively, into two periods, and each pixel of the liquid crystal display element 1 in the first divided period for each of the three fields. Write unit color image data of one color of red, green, and blue to the pixels of each pixel row of one pixel row group out of two pixel row groups in which the rows are grouped by approximately half, and the unit color Illumination light of a color corresponding to image data is emitted from the surface light source 6 to display the unit color image of one color in a portion corresponding to each pixel row of the one pixel row group, and the other of the liquid crystal display element 1 The reset data is written to the pixels in each pixel row of the pixel row group to reset the previous writing state of these pixels, and the one pixel row group is set in the second divided period for each of the three fields. Reset data is written to the pixels of each pixel row of the group to reset the previous writing state of these pixels, and one of the red, green, and blue is added to the pixels of each pixel row of the other pixel row group. Unit color image data of color is written, illumination light of a color corresponding to the unit color image data is emitted from the surface light source 6, and the unit of the one color is applied to a portion corresponding to each pixel row of the other pixel row group Since the color image is displayed, the brightness of the display color of each field is set to the brightness corresponding to the unit color image data to eliminate color shift of the color image, and the frame frequency is sufficiently increased. The display flicker can be eliminated.

For example, when the number of pixel rows of the liquid crystal display element 1 is 160, the first and second divided periods t _1a , t _2a , t _3a, and t _1b , t _2b of the first to third fields in the display sequence. , T _3b unit color image data and reset data writing period of about 1 msec is sufficient, and the display period in which illumination light of each color of red, green and blue is emitted from the surface light source 6 is about 1.5 msec. Therefore, as described above, when the divided periods t _1a , t _1b , t _2a , t _2b , t _3a , and t _3b of the first to third fields are set to about 6.67 msec, respectively. The liquid crystal molecule response period after the writing of the unit color image data and the reset data can be secured sufficiently long as about 4.17 msec.

Therefore, each of the divided periods t _1a , t _1b , t _2a , t _2b , t _3a , and t _3b is sufficient according to the unit color image data and the reset data in which the liquid crystal of the liquid crystal display element 1 is written. Can respond.

  That is, the liquid crystal molecules of the pixels in which the unit color image data has been written correspond to the unit color image data from the previous reset alignment state, that is, the state in which the liquid crystal molecules are aligned substantially perpendicular to the surfaces of the substrates 2 and 3. Since the alignment state is changed in the direction of tilting with respect to the surfaces of the substrates 2 and 3, the liquid crystal molecule response period of about 4.17 msec can be sufficiently caused to respond.

  In addition, the liquid crystal molecules of the pixel in which the reset data is written change the alignment state from the previous writing alignment state to the direction of rising with respect to the substrates 2 and 3, but the reset data is sufficiently high voltage data. Therefore, it is possible to sufficiently respond within a liquid crystal molecule response period of about 4.17 msec.

  Further, the response speed of the liquid crystal of the liquid crystal display element 1 is slowed as the temperature is lowered, but the liquid crystal molecule response period is sufficiently long as about 4.17 msec. It is possible to sufficiently respond according to the unit color image data and the reset data.

  Therefore, according to the field sequential liquid crystal display device, it is possible to eliminate the color shift of the color image by setting the brightness of the display color of each field to the brightness corresponding to the unit color image data.

In the field sequential liquid crystal display device, each of the divided periods t _1a , t _1b , t _2a , t _2b , t _3a , and t _{3b of the} first to third fields is about 6.67 msec. Is sufficiently high at 25 Hz (1 frame = 40 msec), and flickering of the display can be eliminated.

  Therefore, according to the field sequential liquid crystal display device, it is possible to display a high-quality color image without color shift or flicker.

In the field sequential liquid crystal display device of the above embodiment, one pixel row group of the liquid crystal display element 1 is an odd-numbered pixel row group and the other pixel row group is an even-numbered pixel row group. Pixels in which unit color image data is written are displayed on the liquid crystal display element 1 in the first divided periods t _1a , t _2a , t _3a , and the second divided periods t _1b , t _2b , t _3b , respectively. The unit color image display unit corresponding to the row and the non-display unit corresponding to the pixel row in which the reset data is written are alternately displayed for each row, and the unit color image display unit and the non-display unit are Unit color images with good image quality arranged in a balanced manner can be displayed.

In the above-described embodiment, the display control unit 12 is configured to sequentially select each pixel row of the liquid crystal display element 1 and supply a scanning signal, and the odd-numbered pixel rows and the even-numbered pixel rows of the liquid crystal display element 1. In response to the selection of the pixel row, the unit color image data signal and the reset data signal are alternately supplied to each pixel column, and the unit is supplied to the pixel of the odd-numbered pixel row and the pixel of the even-numbered pixel row. Since the data writing means for alternately writing the color image data and the reset data is provided, the first divided period t _1a , t _2a , t _3a and the second divided period t _1b , for each field, The unit color image data and the reset data are written in t _2b and t _3b within the same period, and the frame frequency can be further increased.

  Further, in the field sequential liquid crystal display device of the above embodiment, the display control means 12 performs the pixel control unit 12 for each of the three fields and the pixel row of one pixel row group of the liquid crystal display element 1 and the other pixel row. Since the unit color image data of different colors is written to the pixels of each pixel row of the group, each color of the unit color image of three colors of red, green, and blue for each of the three fields is written. The visual mixing can be improved and a higher quality color image can be displayed.

  In the above embodiment, as shown in FIG. 2, unit color images are displayed in the order of red, blue, and green on each odd-numbered pixel row of the liquid crystal display element 1 in one frame, and even-numbered The unit color images are displayed in the order of green, red, and blue in each pixel row, but the color order of the unit color images displayed in the odd-numbered pixel rows and the even-numbered pixel rows are displayed. The color order of the unit color images to be generated may be other orders.

  In the above embodiment, one pixel row group of the liquid crystal display element 1 is an odd-numbered pixel row group, and the other pixel row group is an even-numbered pixel row group. May be grouped into one pixel row group and the other pixel row group alternately, for example, two to several pixel rows.

1 is an exploded perspective view of a field sequential liquid crystal display device showing an embodiment of the present invention. FIG. 3 is a display sequence diagram of one field of the liquid crystal display device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display element, 6 ... Surface light source, 12 ... Display control means.

Claims (4)

A plurality of pixels have a display area arranged in a matrix in the row direction and the column direction, and unit color image data of three colors of red, green, and blue are sequentially written in the pixels of each pixel row, and these images A liquid crystal display element that displays an image of each unit color according to data;
A surface light source that is disposed on the opposite side of the liquid crystal display element from the observation side and selectively emits illumination light of three colors of red, green, and blue toward the liquid crystal display element;
Three fields obtained by dividing one frame for displaying one color image composed of a plurality of colors into three are each divided into two periods, and in the first divided period for each of the three fields, the liquid crystal display element The unit color image data of one color of red, green, and blue is written to the pixels of each pixel row of one pixel row group among the two pixel row groups in which each pixel row is divided into approximately half. Illuminating light of a color corresponding to the unit color image data is emitted from the surface light source, and the unit color image of one color is displayed in a portion corresponding to each pixel row of the one pixel row group, and the liquid crystal display element Reset data is written to the pixels of each pixel row of the other pixel row group to reset the previous writing state of these pixels, and the one pixel row group is reset during the second divided period for each of the three fields. Reset data is written to the pixels in each pixel row to reset the previous writing state of these pixels, and one of the red, green and blue colors is applied to the pixels in each pixel row of the other pixel row group. Unit color image data is written, illumination light of a color corresponding to the unit color image data is emitted from the surface light source, and the unit color image of one color is applied to a portion corresponding to each pixel row of the other pixel row group A field sequential liquid crystal display device comprising display control means for displaying the display.   2. The field sequential liquid crystal display device according to claim 1, wherein one pixel row group of the liquid crystal display element is an odd-numbered pixel row group, and the other pixel row group is an even-numbered pixel row group.   The display control means sequentially selects each pixel row of the liquid crystal display element and supplies a scanning signal, and each pixel corresponds to selection of the odd-numbered pixel row and the even-numbered pixel row of the liquid crystal display element. The unit color image data signal and the reset data signal are alternately supplied to the column, and the unit color image data and the reset data are alternately written into the pixels of the odd-numbered pixel rows and the pixels of the even-numbered pixel rows. 3. The field sequential liquid crystal display device according to claim 2, further comprising data writing means.   The display control means has unit color image data of different colors for each pixel in each pixel row of one pixel row group of the liquid crystal display element and for each pixel row of the other pixel row group for every three fields. The field sequential liquid crystal display device according to claim 1, wherein:

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