JP5397334B2 - Driving method of display device - Google Patents

Description

This invention relates to a method of driving a field-controlled Viewing device.

The liquid crystal display device is irradiated on the opposite side a plurality of pixels for controlling the transmittance of light and the observation side of the liquid crystal display device having a screen area that is arranged in a matrix, the illumination light toward the liquid crystal display element surface A light source is arranged (see Patent Document 1).

By the way, for example, in a liquid crystal display device mounted on an electronic device such as a mobile phone, the display field of view is a wide field of view, and a narrow field of view so that the display cannot be seen by others other than the user of the liquid crystal display device , The visual field controllability that can be switched to is required.

As a field-control liquid crystal display device, conventionally, a liquid crystal is sealed between a pair of substrates on one surface side of the liquid crystal display element, and a plurality of regions corresponding to the screen of the liquid crystal display element are arranged on the liquid crystal molecules. An alignment state having a visual field in a direction inclined in one direction with respect to the normal line of the liquid crystal display element and an alignment state having a visual field in a direction inclined in the opposite direction to each normal region of the liquid crystal display element If, oriented in each opposing inner surface of the pair of substrates, said to correspond to each partitioned area has been proposed that place the view restrictor liquid crystal device provided with electrodes of a predetermined shape (See Patent Document 2).

  The liquid crystal display device is configured to limit visibility of the display of the liquid crystal display element by reducing visibility from an oblique direction by applying a voltage between electrodes of the visual field limiting liquid crystal element. When a voltage is not applied between the electrodes of the liquid crystal element for display, that is, when the visual field limiting liquid crystal element is in a non-display state, the display image of the liquid crystal display element can be seen in a wide visual field.

  On the other hand, when a voltage is applied between the electrodes of the visual field limiting liquid crystal element, when viewed from one direction with respect to the front direction and a direction inclined in the opposite direction, the display image of the liquid crystal display element is Display of each segmented region having a field of view in a direction inclined in one direction of the liquid crystal element for limiting the field of view and display corresponding to the electrode of the predetermined shape in each segmented region having a field of view in a direction inclined in the opposite direction Since it is hidden, the display image of the liquid crystal display element cannot be recognized from the one direction and the direction inclined in the opposite direction, the field of view of the display image is apparently limited, and the field of view of the display is narrowed. .

JP 2003-149599 A JP 2004-133334 A

  However, the field-of-view-limiting liquid crystal element must be subjected to complicated alignment processing (rubbing processing of the alignment film) in which the direction is different for each of the divided regions on the inner surfaces of the pair of substrates. difficult.

  Therefore, the conventional visual field control type liquid crystal display device provided with the visual field limiting liquid crystal element has a problem of high cost.

The purpose of the present invention is to provide a method of driving a field-controlled Viewing apparatus can be obtained at low cost.

In order to achieve the above-described object, one aspect of the driving method of the display device of the present invention is to guide light emitted from each of two light emitting elements arranged at different positions and A display device driving method comprising: a light source unit that irradiates the display panel with directivity in different directions between light emitting elements, the display image data sequentially supplied from the outside, and the display A step of switching the image data and selected image data selected from any one of the pre-registered fixed image data in a time-division manner and outputting the selected image data to the display panel; and the display image data and the selected image data The first irradiation state in which one of the two light emitting elements is in a light emitting state and the other is in a non-light emitting state, and the two Switching one of the light emitting elements to a non-light-emitting state and a second irradiation state in which the other is in a light-emitting state, and irradiating from the light source unit toward the display panel The light from the two light emitting elements includes light that is given directivity by the light source unit such that the light emission surface is in a normal direction to the light source unit, and the light emission surface is normal to the light source unit. The light source is light that is given directivity by the light source unit so as to be symmetrical in the left-right direction about the axis.
In order to achieve the above-described object, one aspect of the driving method of the display device according to the present invention is to guide the light emitted from each of the two light emitting elements arranged at different positions and to the light. A driving method of a display device comprising a light source unit that irradiates the display panel with directivity in two different directions between two light emitting elements, display image data sequentially supplied from the outside, A step of switching the display image data and selected image data selected from any one of pre-registered fixed image data in a time-division manner and outputting the selected image data to the display panel; and the display image data and the selection In synchronization with the output switching timing with image data, a first irradiation state in which one of the two light emitting elements is in a light emitting state and the other is in a non-light emitting state, Switching one of the two light emitting elements to a second irradiation state in which one of the two light emitting elements is in a non-light emitting state and the other is in a light emitting state, and the display image data is output to the display panel. Sometimes, the light-emitting element that gives directivity to light is set in a light-emitting state so that the light-emitting surface of the two light-emitting elements is in a normal direction to the light source unit, and the selected image data is sent to the display panel. When the light is output, the light emitting element in which the directivity is given to the light so that the light emission surface of the two light emitting elements is symmetric with respect to the light source unit in the left-right direction with respect to the normal line as an axis. It is characterized by that.
In order to achieve the above-described object, one aspect of the driving method of the display device according to the present invention is to guide the light emitted from each of the two light emitting elements arranged at different positions and to the light. A driving method of a display device, comprising: a light source unit that irradiates the display panel with the directivity in two different directions between the two light emitting elements, and irradiates the display panel from the light source unit The light emitted from the two light emitting elements is light having directivity given by the light source unit such that the light emitting surface is in a normal direction to the light source unit, and the light emitting surface is directed to the light source unit. Te is the light given directivity by the light source unit to be symmetrical in the lateral direction normal to an axis, a fixed image data that are sequentially display image data supplied, pre-registered and the display image data from the outside The selected image data selected from any one of them is time-divisionally switched and output to the display panel, and is synchronized with the output switching timing between the display image data and the selected image data. A first irradiation state in which one of the two light-emitting elements is in a light-emitting state and the other is in a non-light-emitting state, and the one of the two light-emitting elements is in a non-light-emitting state and the other is A step of switching between the second irradiation state to be in a light emitting state, and when the narrow viewing angle display is selected, the pre-registered fixed image data is selected as the selected image data, and the wide viewing angle display is performed. when selected is the display image data is selected as the selected image data, the two light emitting element when the display image data is output to the display panel When the selected image data is output to the display panel, the light emitting element that gives directivity to the light is set in a light emitting state so that the light emission surface of the light source is normal to the light source unit. One of the light emitting elements is characterized in that the light emitting element that gives directivity to the light is in a light emitting state so that the light emission surface is symmetrical in the left-right direction with the normal line as an axis with respect to the light source unit .

According to the present invention, it is possible to provide a driving method of a visual field control type display device that can be obtained at low cost.

1 is an exploded perspective view of a liquid crystal display device showing an embodiment of the present invention. The expansion side of a part of surface light source of the said liquid crystal display device. FIG. 3 is an outgoing ray diagram of first and second illumination light from the surface light source. The intensity distribution figure in the left-right direction of the screen of the 1st and 2nd illumination light from the said surface light source. The intensity distribution figure in the up-down direction of the screen of the 1st and 2nd illumination light from the said surface light source. FIG. 3 is a block circuit diagram of driving means of the liquid crystal display device. FIG. 4 is a drive sequence diagram of a liquid crystal display element and a surface light source during wide-field display and narrow-field display in a field sequential liquid crystal display device. FIG. 5 is a drive sequence diagram of a liquid crystal display element and a surface light source in a wide-field display and a narrow-field display in a liquid crystal display device provided with three color filters of red, green, and blue in the liquid crystal display element. The figure which shows an example of the display seen from the front direction at the time of the wide-field display of the said liquid crystal display device, and the display seen from the direction inclined in the left direction and the right direction. The figure which shows an example of the display seen from the direction which looked at the front direction at the time of the narrow-field display of the said liquid crystal display device, and the direction inclined in the left direction and the right direction.

  1 to 7 show an embodiment of the present invention, and FIG. 1 is an exploded perspective view of a liquid crystal display device.

The liquid crystal display device, as shown in FIG. 1, a plurality of pixels for controlling the transmittance of light (not shown) having a screen area 1a arranged in a matrix form, the image data signals to the plurality of pixels Applied to the liquid crystal display element 1 for displaying an image corresponding to the image data, and disposed on the opposite side of the liquid crystal display element 1 from the observation side (upper side in FIG. 1). The first intensity distribution is higher in intensity of the front light emitted in the normal direction of the liquid crystal display element 1 than the intensity of the oblique light emitted in one direction and the opposite direction with respect to the normal. driving the illumination light, and a second illumination light with high intensity distributions than the strength of the intensity of the oblique light the front light, the surface light source 8 for selectively irradiating the liquid crystal display device 1 and the surface light source 8 a drive means 22 for, and is composed of.

Although the internal structure of the liquid crystal display element 1 is not shown, a pair of transparent substrates 2 and 3 joined via a frame-shaped sealing material 4 surrounding the screen region 1a and the substrates 2 and 3 are opposed to each other. Liquid crystal sealed in a region surrounded by the sealing material 4 between the pair of substrates 2 and 3 and a transparent electrode which is provided on each inner surface and forms a plurality of pixels arranged in a matrix by regions facing each other. a layer, a pair of polarizing plates 5 and 6 respectively disposed on an outer surface of the pair of substrates 2 and 3, is made of.

  The liquid crystal display element 1 includes a plurality of pixel electrodes arranged in a matrix in the row direction and the column direction on the inner surface of one substrate 2, and the arrangement region of the plurality of pixel electrodes on the inner surface of the other substrate 3. An active matrix liquid crystal display element provided with a single film-like counter electrode facing each other, and an inner surface of the one substrate 2 is provided with an active element comprising TFTs respectively connected to the plurality of pixel electrodes, and each row A plurality of scanning lines for supplying gate signals to the TFTs and a plurality of data lines for supplying data signals to the TFTs in each column are provided.

  The one substrate 2 has a driver mounting portion 2a extending outward from the other substrate 3, and the plurality of gate lines and data lines are formed from an LSI mounted on the driver mounting portion 2a. Connected to the display driver 7.

  Further, an alignment film is provided on the inner surfaces of the pair of substrates 2 and 3 so as to cover the electrodes, and the liquid crystal molecules of the liquid crystal layer are defined by the alignment film between the pair of substrates 2 and 3. It is oriented in the orientation state.

The liquid crystal display device 1, the liquid crystal molecules a TN or STN type were twisted, the liquid crystal molecules with respect to the substrate 2 side vertically into oriented so the vertical alignment type, the substrate 2 without twisting the liquid crystal molecules, and to three sides flat horizontal alignment type has been oriented to the row, a liquid crystal or a liquid crystal display device of the molecule a bend alignment type to bend or ferroelectric or anti-ferroelectric liquid crystal display device, the pair The polarizing plates 5 and 6 are arranged with their transmission axes oriented so as to obtain good contrast characteristics.

  In the liquid crystal display element 1, a vertical electric field (electric field in the thickness direction of the liquid crystal layer) is generated between the electrodes provided on the inner surfaces of the pair of substrates 2 and 3 to change the alignment state of the liquid crystal molecules. For example, a comb-like first and second electrode for forming a plurality of pixels is provided on the inner surface of one of the pair of substrates 2 and 3, and a horizontal electric field ( A lateral electric field control type that changes the alignment state of the liquid crystal molecules by generating an electric field in a direction along the substrate surface may be used.

  Further, the liquid crystal display element 1 may be a normally white mode display element or a normally black mode display element.

The surface light source 8 includes first and second incident end surfaces 11 and 15 formed on one end surface and the opposite end surface, and the first and second incident end surfaces on the surface facing the liquid crystal display element 1. An exit surface 12 for emitting light incident from the first incident end surface 11 is formed, and the first incident light from the first entrance end surface 11 is incident on the first incident surface with respect to the normal line of the liquid crystal display element 1 from the exit surface 12. The second light that is emitted in a direction inclined in the direction opposite to the end surface 11 and incident from the second incident end surface 15 is incident on the second incident surface from the emission surface 12 with respect to the normal line of the liquid crystal display element 1. a light guide 9 for emitting in a direction inclined in the opposite direction to the end face 15, the to face the exit surface 12 of the light guide 9 is disposed, said first emitted from the emission surface 12 of the light guide 9 One of the second light and the second light is directed in the direction near the normal line of the liquid crystal display element 1 Shines, the other light, a prism sheet 19 to be emitted in one direction and the direction thereof inclined in the opposite direction to the normal line of the liquid crystal display device 1, a first incident end face 11 of the light guide 9 When arranged respectively to face the second incident end face 15, first and second light emitting elements 21a that are selectively lit, which consists of a 21b,.

Figure 2 is an enlarged side view of a portion of the surface light source 8, the light guide 9, a plate-like transparent member such as an acrylic resin plate, a first incident end face 11 is formed on one end face, A first exit surface 12 is formed on one of the two opposing plate surfaces, and the light incident from the first incident end surface 11 is internally reflected on the other plate surface by total reflection at the interface with the outside air. Light emitted from the first emission surface 12 in a direction inclined in the direction opposite to the first incident end surface 11 with respect to the normal line of the liquid crystal display element 1 and incident from the outer surface side of the other plate surface A first light guide plate 10 having a first reflection surface 13 that is transmitted through the first output surface 12 and a plate such as an acrylic resin plate that is separate from the first light guide plate 10. The first light guide plate 10 is formed on the end surface of the first light guide plate 10 opposite to the first incident end surface 11. The incident end face 15 is formed, the second exit face 16 is formed on one of the two opposing plate faces, and the second incident face 15 reflects the light incident from the second incident end face 15 to the second face. The second reflecting surface 17 is formed so as to emit light from the light emitting surface 16 in a direction inclined in the direction opposite to the second incident end surface 15 with respect to the normal line of the liquid crystal display element 1, and the second light emitting surface 17 is formed. a second light guide plate 14 that is disposed to face 16 is opposed to the first reflecting surface of the first light guide plate, and is made of.

  In this embodiment, the reflection surface (second reflection surface) 17 of the second light guide plate 14 is formed by providing a reflection film 18 on the other plate surface. Further, it may be an internal reflection surface that totally reflects light incident from the incident end face (second incident end face) 15 of the second light guide plate 14 at the interface with the outside air.

The first light guide plate 10 has an emission surface (first emission surface) 12 formed as a flat surface, and a reflection surface (first reflection surface) 13 from the first incident end surface 11 side to the light guide plate 10. The wedge-shaped plate is formed on an inclined surface that is inclined in a direction close to the emission surface 12 toward the other end of the liquid crystal display device, the emission surface 12 is opposed to the liquid crystal display element 1, and the emission surface 12 is wherein while the liquid crystal display element 1 and the flat row and the first incident end face 11 is positioned toward the left direction of the liquid crystal display device 1 screen.

Further, the second light guide plate 14 has a reflection surface (second reflection surface) 17 formed as a flat surface, and an emission surface (second emission surface) 16 guided from the second incident end surface 15 side. It consists of the wedge-shaped board formed in the inclined surface inclined at the same angle as the reflective surface 13 of the said 1st light-guide plate 10 in the direction close | similar to the said reflective surface 17 toward the other end side of the optical plate 14, The said output surface 16 are opposed to exist a gap a to the reflecting surface 13 of the first light guide plate, and thereby the emission surface 16 to the reflecting surface 13 and the flat line of the first light guide plate 10, the second The incident end face 15 is arranged facing the right direction of the screen of the liquid crystal display element 1.

  1 and 2, the inclination angle of the reflection surface 13 of the first light guide plate 10 and the inclination angle of the emission surface 16 of the second light guide plate 14 are greatly exaggerated. Is set to about 2 to 10 degrees with respect to the emission surface 12 of the first light guide plate 10 and the reflection surface 17 of the second light guide plate 14.

Meanwhile, the prism sheet 19, on one surface of a transparent film, wherein the first light guide body 9 1 and the second entrance end face 11, 15 and flat row with and the first incident end face 11 side first A plurality of elongated prisms 20 in which the side surface 20a and the second side surface 20b on the second incident end surface 15 side are formed in different shapes are arranged at a pitch that is the same as or smaller than the pixel pitch of the liquid crystal display element 1. The plurality of elongated prisms 20 are arranged in the direction of the first incident end face 11 from the film surface toward the prism top, for example, the first side face 20a on the first incident end face 11 side. The second side surface 20b on the second incident end surface 15 side is formed in the direction of the second incident end surface 15 from the film surface toward the top of the prism. 30-40 ° flat It is formed in a shape formed on a curved surface of an outward bulge having a uniform inclination and a radius of 50 to 90 mm.

Then, the prism sheet 19 is disposed with its prism forming surface the exit surface of the light guide 9, that is to face the exit surface 12 of the first light guide plate 10.

  The first and second light emitting elements 21a and 21b are solid light emitting elements made of LEDs (light emitting diodes), and the first incident end face 11 of the first light guide plate 10 and the second light guiding element. A plurality of the incident end faces 11 and 15 are arranged at intervals in the length direction so as to face the second incident end face 15 of the optical plate 14.

  The surface light source 8 emits light from the first light emitting element 21a when the first and second light emitting elements 21a and 21b are selectively turned on and the first light emitting element 21a is turned on. The first light guided by the first light guide plate 10 and emitted from the emission surface 12 is emitted by the prism sheet 19 in the direction near the normal line of the liquid crystal display element 1.

  Further, the surface light source 8 emits from the second light emitting element 21b when the second light emitting element 21b is turned on, and is guided by the second light guide plate 14 and emitted from the emission surface 16. Further, the second light transmitted through the first light guide plate 10 and emitted from the emission surface 12 is further elongated by the prism sheet 19 with respect to the normal line of the liquid crystal display element 1. The light is emitted in one direction along the direction orthogonal to the vertical direction and a direction inclined in the opposite direction, that is, a direction inclined in the left-right direction of the screen of the liquid crystal display element 1.

FIGS. 3A and 3B are diagrams of outgoing light rays of the first and second illumination lights from the surface light source 8. FIG. 3A shows the outgoing light rays of the first illumination light, and FIG. 3B shows the outgoing light of the second illumination light. Shows light rays.

  As shown in FIG. 3A, the first light emitted from the first light emitting element 21a and incident on the first light guide plate 10 from the first incident end face 11 is the first light guide plate. 10 is reflected by the interface between the reflecting surface 13 and the outside air (air in the gap A between the second light guide plate 14) and the interface between the emitting surface 12 and the outside air (air between the prism sheet 19). Then, the light is emitted from the emission surface 12 of the first light guide plate 10 in a direction inclined in the direction opposite to the first incident end surface 11 with respect to the normal line of the liquid crystal display element 1.

  The first light is incident on the plurality of elongated prisms 20 of the prism sheet 19 from the first side surface 20a made of the linear surface, and is refracted by the second side surface 20b made of the curved surface on the opposite side. Then, the light is emitted from the opposite surface of the prism sheet 19 in the direction near the normal line of the liquid crystal display element 1.

  Further, as shown in FIG. 3B, the second light emitted from the second light emitting element 21b and incident on the second light guide plate 14 from the second incident end face 15 is the second light. The light guide plate 14 is guided while being reflected by the interface between the reflection surface 17 and the emission surface 16 thereof and the outside air (air in the gap A with the first light guide plate 10), and is emitted from the second light guide plate 14. The light is emitted from the surface 16 in a direction tilted in the direction opposite to the second incident end face 15 with respect to the normal line of the liquid crystal display element 1, and further passes through the first light guide plate 10 to transmit the first light. The light is emitted from the first emission surface 12 of the light guide plate 10.

  Then, the second light is incident on the plurality of elongated prisms 20 of the prism sheet 19 from the second side surface 20b made of a curved surface and incident on the first side surface 20a made of the opposite linear surface. Depending on the angle, the liquid crystal display element 1 is reflected by the first side surface 20a, or refracted and transmitted through the first side surface 20a at the interface with the outside air. The light is emitted in the direction inclined to the left and right of the screen with respect to the normal line.

  As described above, the surface light source 8 has the intensity of the front light emitted in the normal direction of the liquid crystal display element 1 with respect to the normal line of the liquid crystal display element 1 by turning on the first light emitting element 21a. The first illumination light having an intensity distribution higher than the intensity of the oblique light emitted in the direction tilted to the left and right of the screen is irradiated toward the liquid crystal display element 1, and the second light emitting element 21b is turned on. Thus, the second illumination light having an intensity distribution in which the intensity of the oblique light is higher than the intensity of the front light is emitted toward the liquid crystal display element 1.

  4 and 5 are intensity distribution diagrams of the first and second illumination lights from the surface light source 8, FIG. 4 is an intensity distribution in the horizontal direction of the screen viewed from the liquid crystal display element 1, and FIG. The intensity distribution in the vertical direction of the screen viewed from the liquid crystal display element 1 side is shown. In FIG. 4, a negative angle is an angle in the left direction of the screen, a positive angle is an angle in the right direction of the screen. In FIG. 5, a positive angle is an upward angle in the screen, a negative angle. The angle is a downward angle of the screen.

  As shown in FIGS. 4 and 5, the first illumination light has the intensity of the front light emitted in the normal direction (0 ° direction) of the liquid crystal display element 1 in the horizontal and vertical intensity distributions. Is sufficiently higher than the intensity of the oblique light emitted in the horizontal and vertical directions with respect to the normal line of the liquid crystal display element 1, and in particular, the intensity distribution in the horizontal direction is about −10 ° to 10 °. The intensity of the front light in a narrow angle range of 0 ° is high, and the intensity of the outgoing light of the oblique light outside the angle range is 20% or less of the intensity of the front light.

  Further, the second illumination light has an intensity distribution in the horizontal direction and the vertical direction, and the intensity of the front light emitted in the normal direction of the liquid crystal display element 1 is the intensity of the front light of the first illumination light. When the intensity distribution in the left-right direction is 20% or less, the intensity of the oblique light in the angle ranges of about −40 ° to −70 ° and about 40 ° to 70 ° is the front light (front light of the second illumination light). The intensity distribution in the vertical direction is light having a distribution with a very small intensity difference depending on the angle.

Next, the driving means 22 for driving the liquid crystal display element 1 and the surface light source 8 will be described. The driving means 22 sends a display image data signal corresponding to an image signal to each pixel of the liquid crystal display element 1, and applying a selection data signal either one is selected from among the fixed image data signal corresponding to the fixed image of the pre-registered pattern display image data signals, are alternately synchronized with the application of the display image data signals Then, the first illumination light is emitted from the surface light source 8 and the second illumination light is emitted from the surface light source 8 in synchronization with the application of the selection data signal.

FIG. 6 is a block circuit diagram of the driving means 22. The driving means 22 includes a fixed image data generator 23 for generating fixed image data corresponding to a fixed image registered in advance, and first and second images. Data memory 24 and 25, and display image data corresponding to an image signal supplied from the outside are written into first memory 24 of first and second image data memories 24 and 25, and the display image data and A memory write control unit 26 that selectively writes fixed image data to the second memory 25 in accordance with a visual field selection signal, and alternately reads the image data written to the first memory 24 and the second memory 25. The memory read controller 27 supplied to the data line controller 7a of the display driver 7 mounted on the liquid crystal display element 1 and the first and second light emitting elements 21a and 21b of the surface light source 8 are selectively used. A light source driving unit 28 for lit, consists with the memory write controller 26 and the memory read controller 27 and the light source driving unit 28 and the drive control unit 29 controls the scanning line control unit 7b of the display driver 7, .

  The driving means 22 is supplied to the drive control unit 29 from a circuit unit (not shown) of the electronic device by operating a visual field selection key provided in the electronic device such as a mobile phone equipped with a liquid crystal display device. The same display image corresponding to the display image data is alternately displayed on the liquid crystal display element 1 according to a field selection signal, or a display image corresponding to the display image data and a fixed image data corresponding to the fixed image data are displayed. Display images alternately.

  That is, the driving means 22 writes display image data corresponding to the image signal to the first memory 24 and the second memory 25 when a visual field selection signal for selecting wide-field display is input. The display image data is read from the first memory 24 and supplied to the data line driver in one of two divided periods obtained by dividing one frame for displaying the image of the image into two, and a display corresponding to the display image data is displayed. An image data signal is applied to each pixel of the liquid crystal display element 1, and the first illumination light is irradiated from the surface light source 8 by turning on the first light emitting element 21 a in synchronization therewith, and in the other divided period. The display image data read from the second memory 25 is supplied to the data line driving unit, and a display image data signal corresponding to the display image data is applied to each pixel of the liquid crystal display element 1. It irradiates the second illumination light from the surface light source 8 is synchronized with lighting of the second light emitting element 21b in.

  The driving means 22 writes the display image data into the first memory 24 and reads out the fixed image data from the fixed image data generator 23 when a visual field selection signal for selecting narrow-field display is input. The fixed image data is written into the second memory 25, and the display image data is read from the first memory 24 and supplied to the data line driving unit in one of two divided periods obtained by dividing the one frame into two, A display image data signal corresponding to the display image data is applied to each pixel of the liquid crystal display element 1, and the first illumination light is emitted from the surface light source 8 by turning on the first light emitting element 21a in synchronization therewith. In the other divided period, the fixed image data is read from the second memory 25 and the fixed image data is supplied to the data line driving unit. Applying a fixed image data signal corresponding to data to each pixel of the liquid crystal display device 1, it is irradiated with the second illuminating light from the surface light source 8 is synchronized with lighting of the second light emitting element 21b in.

  In the liquid crystal display device, the liquid crystal display element 1 is a display element that does not include a color filter, and the first and second light emitting elements 21a and 21b of the surface light source 8 are respectively a red LED, a green LED, and a blue LED. In the field sequential liquid crystal display device, the first illumination light and the second illumination light of the three colors red, green, and blue are sequentially emitted from the surface light source 8. The liquid crystal display element 1 is provided with color filters of three colors of red, green, and blue respectively facing the plurality of pixels, and white first illumination light and second illumination light are emitted from the surface light source 8. A liquid crystal display device which is selectively irradiated may be used.

  7A and 7B are driving sequence diagrams of the liquid crystal display element 1 and the surface light source 8 in the field sequential liquid crystal display device. FIG. 7A shows a driving sequence for wide-field display, and FIG. 7B shows a driving sequence for narrow-field display. The drive sequence is shown.

In the case of this field sequential liquid crystal display device, one frame is divided into six fields t _{1 to} t _6, and in the case of wide-field display, the one frame is divided into two as shown in FIG. On the other hand, for example, for each of the first to third fields t ₁ , t ₂ , and t ₃ that are the first divided period, a red unit color display image data signal and a green color are displayed on each pixel of the liquid crystal display element 1. and display image data signals of unit colors, the display image data signals of unit colors of blue, sequentially applies the, in synchronization with the application of these display image data signals of each unit color, from the surface light source 8, red a first illumination light, a first illumination light green, the first illumination light of blue, sequentially emit.

Further, a red unit color is displayed on each pixel of the liquid crystal display element 1 for each of the _{fourth to} sixth fields t ₄ , t ₅ , and t ₆ , which is the latter half of the one frame divided into two. the image data signals, and the display image data signals of green unit colors, sequentially applies the display image data signals of unit colors of blue, and in synchronization with the application of these display image data signals of each unit color, the from the surface light source 8, and the second illumination light red, and a second illumination light green, and a second illumination light blue, sequentially emit.

In the narrow-field display, as shown in FIG. 7B, for example, the liquid crystal display element is used for each of the first to third fields t ₁ , t ₂ , and t ₃ that are the first divided period. to each pixel of 1, and the unit color display image data signals of red, a unit color display image data signals of green, and the display image data signals of unit colors of blue, sequentially applying, each unit color of these in synchronization with the application of the display image data signals, from the surface light source 8, a first illumination light red, first illumination light green, the first illumination light of blue, sequentially emit the second half divided period For each of the _{fourth to} sixth fields t ₄ , t ₅ and t ₆ , a fixed image data signal of red unit color and a fixed image of green unit color are applied to each pixel of the liquid crystal display element 1. A data signal and a blue unit color fixed image data signal are sequentially applied , and the fixed image data of each unit color is applied. In synchronization with the application of the data signal, from the surface light source 8, and the second illumination light red, and a second illumination light green, and a second illumination light blue, sequentially emit.

  FIG. 7 shows a driving sequence in which the sequential application of the display image data signals in the unit colors of red, green, and blue and the sequential application of the fixed image data signals in the unit colors of red, green, and blue are alternately performed. However, the present invention is not limited to this, for example, application of a display image data signal of one unit color of red, green, and blue, and application of a fixed image data signal of one unit color of red, green, and blue The first illumination light of the unit color is emitted in synchronization with the application of the display image data signal, and the second illumination light of the unit color is synchronized with the application of the fixed image data signal. May be emitted.

  FIG. 8 is a drive sequence diagram of the liquid crystal display element 1 and the surface light source 8 in the liquid crystal display device in which the liquid crystal display element 1 is provided with color filters of three colors of red, green, and blue that face the plurality of pixels. A, (a) shows a driving sequence for wide-field display, and (b) shows a driving sequence for narrow-field display.

For this liquid crystal display device, the one frame is divided into two periods, when the wide-field display, as shown in FIG. 8 (a), the example in the first divided period t _11, the liquid crystal display device 1 A display image data signal of each color of red, green, and blue is applied to each pixel corresponding to each of the red, green, and blue color filters, and in synchronization with the application of the display image data signal, white light is emitted from the surface light source 8. to emit the first illumination light color, similarly to the second divided period t _12, the each pixel of the liquid crystal display device 1, is applied red, green, and color display image data signals of blue, the display in synchronization with the application of image data signals to emit the second illumination light in white color from the surface light source 8.

Also, when the narrow-angle view, as in FIG. 8 (b), for example, the the first divided period t _11, the liquid crystal display device 1, red, green, and each pixel corresponding to the blue color filter , red, green, and applying a respective color display image data signals of blue, in synchronism with application of the display image data signals, to emit the second illumination light white color from the surface light source 8, the second divided period to t _12, the each pixel of the liquid crystal display device 1, the red, green, and applying a respective color fixed image data signals of blue, the fixed image data signals in synchronism with the application of, the white color from the surface light source 8 Second illumination light is emitted.

The liquid crystal display device has a screen area 1a in which a plurality of pixels arranged in a matrix to control the transmittance of light, the image data signal is applied to each of the plurality of pixels, an image corresponding to the image data The intensity of the front light emitted in the normal direction of the liquid crystal display element 1 toward the liquid crystal display element 1 is opposite to the observation side of the liquid crystal display element 1 to be displayed in one direction with respect to the normal line. And the first illumination light having an intensity distribution higher than the intensity of the oblique light emitted in the opposite direction, that is, the direction inclined to the left and right, and the intensity of the oblique light is higher than the intensity of the front light. a second illumination light distribution, the surface light source 8 selectively irradiating arranged, by driving means 22 for driving the surface light source 8 and the liquid crystal display device 1, each pixel of the liquid crystal display device 1 Display image data corresponding to the image signal No. and the and any selection data signal one of which is selected in the display image data with a previously registered pattern fixed image data signal corresponding to the fixed image, is applied alternately, the display image data signals The first illumination light is irradiated from the surface light source 8 in synchronization with the application, and the second light source 8 is applied from the surface light source 8 in synchronization with the application of the selection data signal (display image data signal or fixed image data signal). Since the illumination light is irradiated, the display field of the liquid crystal display element 1 can be controlled to a wide field and a narrow field.

That is, the liquid crystal display device, an image corresponding to the display image data, and image either one corresponding to the selected selection data of the fixed image data and the display image data, in which alternately displays A first illumination having an intensity distribution in which the intensity of the front light from the surface light source 8 is higher than the intensity of the oblique light by applying the display image data signal to each pixel of the liquid crystal display element 1 and synchronizing it; An image corresponding to the display image data is displayed by irradiating light, the selection data signal is applied to each pixel of the liquid crystal display element 1, and the intensity of the oblique light from the surface light source 8 is synchronized with it. An image corresponding to the selection data is displayed by irradiating the second illumination light having an intensity distribution higher than the intensity of the front light.

  Therefore, the display corresponding to the display image data is a display having a luminance distribution peak in the front direction (direction near the normal line of the liquid crystal display element 1), that is, a display in which the field of view is limited to the front direction. The display corresponding to the selection data is a display having a peak of luminance distribution in a direction inclined in one direction (left direction) and the opposite direction (right direction) with respect to the front direction, that is, the field of view is the front side. The display is limited to the direction tilted leftward and rightward with respect to the direction.

  Therefore, when display image data is selected as the selection data, images corresponding to the same display image data are alternately displayed and tilted from the front direction to the left and right directions with respect to the front direction. It is possible to perform wide-field display that allows a display image corresponding to an image signal to be observed from a different direction.

  FIG. 9 shows an example of the display viewed from the front direction and the display viewed from the direction tilted leftward and rightward in the wide-field display.

  On the other hand, when the fixed image data is selected as selection data, an image corresponding to the display image data and an image corresponding to the fixed image data are alternately displayed, and the fixed image data is Since the data corresponds to the fixed image of the pattern registered in advance, the display image corresponding to the display image data cannot be viewed from the direction inclined with respect to the front direction, and the display image However, since a fixed image having a pattern corresponding to the fixed image data is displayed, the display image cannot be viewed at all, and a narrow field display in which the field of view of the display image corresponding to the image signal is limited to the front direction can be performed. .

  FIG. 10 shows an example of the display viewed from the front direction and the display viewed from the direction tilted leftward and rightward in the narrow-field display. Here, a display image corresponding to the display image data is shown. And a checkered fixed image are alternately displayed.

  The checkered fixed image may be an image of a pattern in which square patterns of a plurality of colors of red, green, blue, or mixed colors of yellow, magenta, cyan, and black are alternately arranged in a row direction and a column direction. Alternatively, an image of a pattern in which white and black rectangular patterns of mixed colors of red, green, and blue are alternately arranged in a row direction and a column direction may be used.

  Furthermore, the fixed image is not limited to a checkered pattern, and may be a stripe pattern, a mark, a character, or the like.

In this liquid crystal display device, the intensity of the front light emitted in the normal direction of the liquid crystal display element 1 toward the liquid crystal display element 1 is opposite to the observation side of the liquid crystal display element 1. First illumination light having an intensity distribution higher than the intensity of the oblique light emitted in one direction with respect to the line and the direction inclined in the opposite direction, and the intensity of the oblique light is higher than the intensity of the front light a second illumination light distribution, the surface light source 8 selectively irradiating arranged, by driving means 22 for driving the liquid crystal display element 1 and the surface light source 8, to each pixel of the liquid crystal display device 1, and display image data signal corresponding to an image signal, and applies the selected data signal selects one of the fixed image data signal corresponding to the fixed image of the display image data signals with a previously registered pattern, alternately, Mark of the display image data signal The first illumination light is emitted from the surface light source 8 in synchronization with the second illumination light, and the second illumination light is emitted from the surface light source 8 in synchronization with the application of the selection data signal. Therefore, it can be obtained at a much lower cost than a conventional visual field control type liquid crystal display device provided with a liquid crystal element for visual field limitation that is difficult to manufacture.

  In this liquid crystal display device, the intensity of the front light of the second illumination light is desirably set to 20% or less of the intensity of the front light of the first illumination light, as described above. Thereby, the contrast of the display image observed from the front direction in the narrow-field display can be sufficiently increased.

In the liquid crystal display device, the surface light source 8 includes first and second incident end surfaces 11 and 15 formed on one end surface and the opposite end surface, and the surface facing the liquid crystal display element 1 An emission surface 12 for emitting light incident from the first and second incident end surfaces 11 and 15 is formed, and the first light incident from the first incident end surface 11 is transmitted from the emission surface 12 to the liquid crystal display element 1. The liquid crystal display element 1 emits second light incident from the second incident end face 15 through the second incident end face 15 in a direction inclined in the direction opposite to the first incident end face 11 with respect to the normal line. opposite the light guide 9 is emitted in a direction inclined to the direction, the first and second entrance end face 11, 15 and the flat line of the light guide 9 and the second entrance end face 15 with respect to the normal to the In addition, the side surface on the first incident end surface 11 side and the side surface on the second incident end surface 15 side are mutually interchanged. A plurality of elongated prisms 20 formed in different shapes, the to face the exit surface 12 of the light guide 9 is arranged, wherein said first emitted from the emission surface 12 of the light guide 9 and the second Out of the plurality of elongated prisms 20, one light incident from one side surface (first side surface) 20 a thereof is emitted toward a direction near the normal line of the liquid crystal display element 1, The other light incident on the elongated prism 20 from the other side surface (second side surface) 20b is along the direction perpendicular to the length direction of the elongated prism 20 with respect to the normal line of the liquid crystal display element 1. a prism sheet 19 to be emitted in one direction and the direction thereof inclined in the opposite direction, are arranged respectively to face the first incident end face 11 and the second entrance end face 15 of the light guide 9, selectively lighting First and second light emitting elements 21a Due to the configuration and 21b, the first illumination light of higher intensity distribution than the strength of the intensity of the front light is the oblique light, high strength distribution than the strength of the intensity of the oblique light the front light second illumination light selectively irradiates the toward the liquid crystal display device 1 of, and simplify the manufacturing of the surface light source 8, the liquid crystal display device can be obtained further low cost.

Further, the liquid crystal display device, a light guide 9 of the surface light source 8, a plate-shaped transparent member, the first incident end face 11 on one end surface is formed, on one of the two plate surfaces facing A first exit surface 12 is formed, and the light incident from the first incident end surface 11 is internally reflected on the other plate surface, so that the first exit surface 12 and the normal line of the liquid crystal display element 1 are reflected. Thus, a first reflecting surface 13 is formed that is emitted in a direction inclined in a direction opposite to the first incident end surface 11 and transmits light incident from the outer surface side and is emitted from the first emission surface 12. The first light guide plate 10 and the first light guide plate 10 are made of a plate-like transparent member that is a separate body, and the first light guide plate 10 has a first end face on the opposite side to the first incident end face 11. 2 incident end faces 15 are formed, a second exit face 16 is formed on one of the two opposing plate faces, and the other The light incident on the surface from the second incident end face 15 is reflected and tilted in the direction opposite to the second incident end face 15 with respect to the normal line of the liquid crystal display element 1 from the second emitting face 16. A second reflection surface 17 is formed to emit in the direction, and the second light guide plate 14 is disposed so that the second emission surface 16 faces the first reflection surface 13 of the first light guide plate 10. , constituted by, is opposed to the first is opposed to the incident end face 11 of the first light emitting element 21a arranged, a second entrance end face 15 of the second light guide plate 14 of the first light guide plate 10 It is preferable to arrange the second light emitting element 21b, and by doing so, the light from the first and second light emitting elements 21a, 21b is transmitted by the first and second light guide plates 10, 14. Efficiently guiding, from the first exit surface 12 of the first light guide plate 10, the First illumination light of sufficiently high intensity distribution than the strength of the intensity of the surface light the oblique light, and the second illumination light sufficiently high intensity distribution than the intensity of the oblique light intensity of the front light , it can be irradiated toward the selectively the liquid crystal display device 1.

In this embodiment, the light guide body 9 of the surface light source 8 constituted by the first and second light guide plates 10 and 14, but the light guide 9, a plate-like transparent member The first incident end surface and the second incident end surface are formed on one end surface and the other end surface facing each other, the exit surface is formed on one of the two opposing plate surfaces, and the first plate is formed on the other plate surface. The light incident from the first incident end face is internally reflected and emitted from the emission face in a direction inclined to the direction opposite to the first incident end face with respect to the normal line of the liquid crystal display element 1. A light guide plate configured to reflect the light incident from the incident end face on the inner surface and emit the light from the emission face in a direction inclined to the direction opposite to the second incident end face with respect to the normal line of the liquid crystal display element 1. The first incident end face and the second incident end face of the light guide plate are respectively opposed to the first incident end face. An optical element 21a and the second light-emitting element 21b may be disposed.

1 ... liquid crystal display device, 1a ... screen area, 8 ... surface light source, 9 ... lightguide 10 ... first light guide plate, 11 ... first entrance end face, 12 ... of the first light exit surface (light guide (Exit surface), 13 ... first reflective surface, 14 ... second light guide plate, 15 ... second incident end surface, 16 ... second output surface, 17 ... second reflective surface, 19 ... prism sheet, 20 ... elongated prisms, 21a, 21b ... light emitting elements, 22 ... driving means.

Claims (17)

The light emitted from each of the two light emitting elements arranged at different positions is guided, and the display panel is irradiated with the light with directivity in different directions between the two light emitting elements. A driving method of a display device including a light source unit,
The display image data sequentially supplied from the outside, and the display image data and the selected image data selected from one of the pre-registered fixed image data are switched in a time division manner and output to the display panel. And steps to
In synchronization with the output switching timing between the display image data and the selected image data, a first irradiation state in which one of the two light emitting elements is in a light emitting state and the other is in a non-light emitting state, Switching between a second irradiation state in which one of the two light emitting elements is in a non-light emitting state and the other is in a light emitting state;
Have
Light from the two light emitting elements irradiated from the light source unit toward the display panel is light that is given directivity by the light source unit such that a light emission surface is in a normal direction with respect to the light source unit. And light that is given directivity by the light source unit such that the light exit surface is symmetrical in the left-right direction with respect to the light source unit as a normal line.
A driving method of a display device. When the display image data is output to the display panel, a light emitting element that emits directivity to light is emitted so that a light emission surface of the two light emitting elements is in a normal direction to the light source unit. State
When the selected image data is output to the display panel, the light has directivity so that the light emission surface of the two light emitting elements is symmetrical with respect to the light source unit in the horizontal direction with respect to the normal line. 2. The method for driving a display device according to claim 1, wherein a given light emitting element is brought into a light emitting state.   When the narrow viewing angle display is selected, the fixed image data registered in advance is selected as the selected image data, and when the wide viewing angle display is selected, the display image data is selected as the selected image data. The method for driving a display device according to claim 1, wherein the display device is a driving method. The light emitted from each of the two light emitting elements arranged at different positions is guided, and the display panel is irradiated with the light with directivity in different directions between the two light emitting elements. A driving method of a display device including a light source unit,
The display image data sequentially supplied from the outside, and the display image data and the selected image data selected from one of the pre-registered fixed image data are switched in a time division manner and output to the display panel. And steps to
In synchronization with the output switching timing between the display image data and the selected image data, a first irradiation state in which one of the two light emitting elements is in a light emitting state and the other is in a non-light emitting state, Switching between a second irradiation state in which one of the two light emitting elements is in a non-light emitting state and the other is in a light emitting state;
Have
When the display image data is output to the display panel, a light emitting element that emits directivity to light is emitted so that a light emission surface of the two light emitting elements is in a normal direction to the light source unit. State
When the selected image data is output to the display panel, the light has directivity so that the light emission surface of the two light emitting elements is symmetrical with respect to the light source unit in the horizontal direction with respect to the normal line. A given light emitting element is in a light emitting state,
A driving method of a display device.   Light from the two light emitting elements irradiated from the light source unit toward the display panel is light that is given directivity by the light source unit such that a light emission surface is in a normal direction with respect to the light source unit. 5. The display device according to claim 4, wherein the light emitting surface is light that is given directivity by the light source unit such that the light emission surface is symmetrical in the left-right direction with respect to the light source unit as a normal line. Driving method.   When the narrow viewing angle display is selected, the fixed image data registered in advance is selected as the selected image data, and when the wide viewing angle display is selected, the display image data is selected as the selected image data. 6. The method for driving a display device according to claim 4, wherein the display device is driven. The light emitted from each of the two light emitting elements arranged at different positions is guided, and the display panel is irradiated with the light with directivity in different directions between the two light emitting elements. A driving method of a display device including a light source unit,
Light from the two light emitting elements irradiated from the light source unit toward the display panel is light that is given directivity by the light source unit such that a light emission surface is in a normal direction with respect to the light source unit. And light that is given directivity by the light source unit such that the light exit surface is symmetrical in the left-right direction with the normal line as an axis with respect to the light source unit,
The display image data sequentially supplied from the outside, and the display image data and the selected image data selected from one of the pre-registered fixed image data are switched in a time division manner and output to the display panel. And steps to
In synchronization with the output switching timing between the display image data and the selected image data, a first irradiation state in which one of the two light emitting elements is in a light emitting state and the other is in a non-light emitting state, Switching between a second irradiation state in which one of the two light emitting elements is in a non-light emitting state and the other is in a light emitting state;
Have
When the narrow viewing angle display is selected, the pre-registered fixed image data is selected as the selected image data, and when the wide viewing angle display is selected, the display image data is selected as the selected image data ,
When the display image data is output to the display panel, a light emitting element that emits directivity to light is emitted so that a light emission surface of the two light emitting elements is in a normal direction to the light source unit. State
When the selected image data is output to the display panel, the light has directivity so that the light emission surface of the two light emitting elements is symmetrical with respect to the light source unit in the horizontal direction with respect to the normal line. A given light emitting element is in a light emitting state,
A driving method of a display device. The display image data and the selected image data are each composed of a red component, a green component, and a blue component,
The driving method of a display device according to any one of claims 1 to 7, characterized in that the output the to the display panel in a time division manner switched each color component. Each of the two light emitting elements includes a red LED, a green LED, and a blue LED,
9. The display device drive according to claim 8 , wherein an LED having a color corresponding to a color component output to the display panel is turned on and the other LEDs are turned off for the light emitting element in the light emitting state. Method. The display image data and the selected image data are red, green, and blue color data corresponding to the red, green, and blue pixels of the display panel, respectively.
The driving method of the display device according to any one of claims 1 to 7, characterized in that the components a time division manner switched output to the display panel. Each of the two light emitting elements is a white LED,
11. The display device according to claim 10 , wherein a white LED corresponding to each component output to the display panel is turned on and the other white LEDs are turned off for the light emitting element in the light emitting state. Driving method. Each of the two light emitting elements includes a red LED, a green LED, and a blue LED,
The light emitting element of the light-emitting state, the red LED corresponding to each component to be output to the display panel, a green LED and a blue LED causes simultaneously turned in claim 10, characterized in that turns off the other LED A driving method of the display device. The fixed image data driving method of a liquid crystal display device according to any one of claims 1 to 12, characterized in that it corresponds to the mosaic image. The two light emitting elements, the driving method of a display device according to any one of claims 1 to 13, characterized in that it is arranged so as to emit light toward the different end surfaces of the light source unit. The said two light emitting elements are arrange | positioned so that the emission direction of the light inject | emitted toward the said light source part may become an antiparallel direction mutually, The one of Claims 1 thru | or 14 characterized by the above-mentioned. Method for driving the display device. The driving method of a display device according to any one of claims 1 to 15, characterized in that the two light emitting elements are arranged opposite. The light source unit driving method of a display device according to any one of claims 1 to 16, characterized in that it consists of a first light guide plate and the second light guide plate and a prism sheet.

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