JP2005024627A - Display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus which improves the display grade of a three-dimensional image. <P>SOLUTION: When a first light source 13 is lighted up at first, light emitted from a light-emitting surface 15 of a first light transmission plate 2 is transmitted through a liquid crystal display panel 1 and a second light transmission plate 3. Thereby, image light corresponding to drive of the liquid crystal display panel 1 at that time is emitted as front display light using a front face of the liquid crystal display panel 1 as a virtual screen. On the other hand, when a second light source 14 is lighted up, light emitted from a light-emitting surface 17 of the second light transmission plate 3 is transmitted through the liquid crystal display panel 1 and the first light transmission plate 2 and then is reflected by a reflection plate 4. Reflected light is transmitted through the first light transmission plate 2, the liquid crystal display panel 1 and the second light transmission plate 3 and thereby, image light corresponding to drive of the liquid crystal display panel 1 at that time is emitted as backward display light using a reflecting surface of the reflection plate 4 as the virtual screen. The three-dimensional picture is displayed by an afterimage phenomenon of the front display light and the backward display light. Since the front display light and the backward display light are separately obtained in this case, display grade can be improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device that displays a stereoscopic image.
[0002]
[Prior art]
For example, in a liquid crystal display device that displays a three-dimensional image, a right-eye image and a left-eye image are alternately displayed at high speed on a liquid crystal display panel, and a three-dimensional image is displayed by an afterimage phenomenon. There are some (see, for example, Patent Document 1). The method described in Patent Document 1 is based on the fact that the characteristic of transmitted light intensity with respect to the viewing angle of the liquid crystal changes depending on the driving voltage, and is determined as a reference for the liquid crystal display panel when displaying the right-eye image. When displaying a left-eye image by applying a driving voltage that gives the highest contrast at an angle from the position of the right eye with respect to the normal from the (reference point), the angle from the position of the left eye A driving voltage that gives the highest contrast is applied to the liquid crystal display panel.
[0003]
[Patent Document 1]
JP-A-9-127462
[0004]
[Problems to be solved by the invention]
However, in the conventional liquid crystal display device, since the characteristic of the transmitted light intensity with respect to the viewing angle of the liquid crystal changes depending on the driving voltage, when the right eye image is displayed, the right eye image is displayed on the left side. The image for the left eye is not invisible at all, just because it becomes difficult to see with the eye. Also, when the image for the left eye is displayed, the image for the left eye is not only invisible with the right eye, so it is not visible at all. There was a problem that would decrease. . Further, in this method, only the point where the viewing angle determined by the positional relationship between the line of sight and the image has a predetermined positional relationship, that is, the reference point and the display image in the vicinity thereof can be viewed stereoscopically. Since the viewing angle is different for each display position on the screen, in order to visually recognize a good stereoscopic display, observation must be performed including the movement of the neck in the horizontal direction corresponding to the display position. There was also a problem of being very tired.
[0005]
Accordingly, an object of the present invention is to provide a display device capable of improving the display quality of a stereoscopic image.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 drives one or more display panels that display a front display image and a rear display image, one or more light source panels that irradiate the display panel with light, and the display panel. Display driving means for alternately displaying a front display image and a rear display image; and a light source control means for turning on the light source panel in accordance with the display of the front display image and the rear display image of the display panel. A stereoscopic image can be visually recognized by adding a luminance difference to the image and the rear display image.
According to a second aspect of the present invention, in the first aspect of the present invention, the display panel is driven by a field sequential method.
According to a third aspect of the present invention, in the first aspect of the present invention, the display panel is a homogeneously oriented liquid crystal display panel.
According to a fourth aspect of the present invention, in the first aspect of the invention, the light source panel includes a light guide plate and a light source disposed on one end surface of the light guide plate.
According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the light guide plate refracts the light emitted from the light source toward a surface opposite to the light emission surface from which light is emitted. And an optical path changing optical surface.
According to a sixth aspect of the invention, in the first aspect of the invention, the light source panel includes a first light source panel disposed in front of the display panel and a second light source panel disposed in the rear of the display panel. A reflective layer is disposed behind the second light source panel, the second light source panel is turned on while the display panel is displaying a front display image, and the display panel is The first light source panel is turned on while a rear display image is being displayed, and is reflected by the reflective layer.
The invention according to claim 7 is the invention according to claim 6, wherein the reflective layer is a concave mirror.
According to an eighth aspect of the present invention, in the first aspect of the invention, the display panel includes a first display panel that displays a front display image and a second display panel that is disposed behind the display panel and displays a rear display image. A display panel is included.
The invention according to claim 9 is the invention according to claim 8, wherein the light source panel is disposed between the first display panel and the second display panel, and the front of the first display panel. It includes a first light source panel that is lit while displaying a display image, and a second light source panel that is lit while displaying a rear display image on the second display panel.
The invention according to claim 10 is the invention according to claim 8, wherein the first display panel, the second display panel, and the light source panel are arranged in this order, and the front display image is displayed on the first display panel. , The rear display image is displayed on the second display panel, and the light source panel is turned on while the front display image and the rear display image are displayed.
According to an eleventh aspect of the present invention, in the first aspect of the invention, the display panel includes a liquid crystal display panel having substrates disposed opposite to each other and having electrodes on the inner surface thereof. One of the substrates is provided with a reflective electrode disposed adjacent to the electrode.
According to a twelfth aspect of the present invention, in the invention according to the eleventh aspect, an area corresponding to one of the front display image and the rear display image on the liquid crystal display panel corresponding to the electrode adjacent to the reflective electrode by the display driving unit. An area corresponding to the reflective electrode is displayed in a non-transmissive state during display in the LCD, and an electrode adjacent to the reflective electrode is displayed during display of the other of the front display image and the rear display image on the liquid crystal display panel in the area corresponding to the reflective electrode. The liquid crystal display panel is driven and controlled so that a region corresponding to the above is in a transmissive state.
A thirteenth aspect of the invention is characterized in that, in the invention of the twelfth aspect, a reflective layer is disposed behind the light source panel.
And according to this invention, a three-dimensional image can be displayed by the afterimage phenomenon with the front display light and back display light obtained alternately. In this case, no back display light is generated at the time of display with the front display light, and no front display light is generated at the time of display with the back display light, so that the display quality is improved. be able to. Further, there is no reference point when observing, and therefore it is not necessary to move the neck in the horizontal direction, and it is possible to reduce fatigue.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a plan view of a main part of a liquid crystal display device as a first embodiment of the present invention. In this liquid crystal display device, the first light guide plate 2 is disposed on the rear side of the liquid crystal display panel 1 disposed perpendicular to the horizontal plane, and the second light guide plate 3 is disposed on the front side of the liquid crystal display panel 1. A reflector 4 is disposed on the rear side of the first light guide plate 2.
[0008]
The first and second light guide plates 2 and 3 are formed in a square plate shape with a transparent resin, and the right end surfaces thereof are plane incidence surfaces 11 and 12. First and second light sources comprising light emitting diode arrays and the like incorporating red (R), green (G), and blue (B) light emitting diodes at positions facing substantially the entire incident surfaces 11 and 12, respectively. 13 and 14 are arranged.
[0009]
The front surface (the surface facing the liquid crystal display panel 1) of the first light guide plate 2 is a flat emission surface 15, and the rear surface is an optical path changing optical surface 16. The rear surface of the second light guide plate 3 (the surface facing the liquid crystal display panel 1) is a flat emission surface 17, and the front surface is an optical path changing optical surface 18. Details of the optical path changing optical surfaces 16 and 18 will be described later. In FIG. 1, an image displayed on the liquid crystal display panel 1 by driving to be described later is observed by an observer from the front (lower side in FIG. 1) of the second light guide plate 3.
[0010]
Next, FIG. 2 shows an enlarged cross-sectional plan view of a part of the liquid crystal display panel 1. The liquid crystal display panel 1 is an active matrix type, and includes an active substrate 21 and a counter substrate 22 made of a glass substrate or the like. In this case, the active substrate 21 is arranged on the rear side and the counter substrate 22 is arranged on the front side, but this arrangement may be reversed.
[0011]
On the inner surface of the active substrate 21 (the surface facing the counter substrate 22), a plurality of pixel electrodes 23 arranged in a matrix in the row direction and the column direction, and a plurality of thin film transistors respectively connected to the pixel electrodes 23 24, a plurality of gate lines (not shown) for supplying gate signals to the thin film transistors 24 in each row, a plurality of data lines (not shown) for supplying data signals to the thin film transistors 24 in each column, An alignment film 25 is provided.
[0012]
On the inner surface of the counter substrate 22 (the surface on the side facing the active substrate 21), a solid counter electrode 26 disposed so as to oppose all the pixel electrodes 23 of the active substrate 21 and an orientation covering the counter electrode 26. A film 27 is provided. In this case, the alignment films 25 and 27 are aligned in parallel with each other and in opposite directions.
[0013]
The active substrate 21 and the counter substrate 22 are bonded to each other via a seal material (not shown). A liquid crystal 28 is sealed between the alignment films 25 and 27 of both the substrates 21 and 22 inside the sealing material. In this case, the liquid crystal 28 is a nematic liquid crystal having a positive dielectric anisotropy, and the alignment film 25, with its liquid crystal molecules 28a tilted at a predetermined pretilt angle with respect to the alignment films 25 and 27, It is homogeneously oriented along 27 orientation treatment directions.
[0014]
A polarizing plate 29 is attached to the outer surface of the active substrate 21. A phase difference plate 30 is attached to the outer surface of the counter substrate 22, and a polarizing plate 31 is attached to the outer surface. In this case, the transmission axes of the polarizing plates 29 and 31 are aligned with the direction of approximately 45 ° with respect to the homogeneous alignment direction of the liquid crystal molecules 28a (the alignment treatment direction of the alignment films 25 and 27), and the respective transmission axes. Are arranged so as to be substantially orthogonal to each other. The phase difference plate 30 is for increasing the display contrast and widening the viewing angle, and is arranged so that the slow axis thereof is substantially orthogonal to the homogeneous alignment direction of the liquid crystal molecules 28a.
[0015]
Next, FIG. 3 shows an enlarged plan view of a part of the first light guide plate 2. The optical path changing optical surface 16 of the first light guide plate 2 is an inclined surface on the incident surface 11 side (right side in FIG. 3) of the projection having a triangular cross-section formed in parallel with the incident surface 11 shown in FIG. A high-angle inclined surface 16a having a high inclination angle θ1 with respect to the emission surface 15 and a low-angle inclination surface 16b having a low inclination angle θ2 with respect to the emission surface 15 and made of an inclined surface on the opposite side.
[0016]
Next, FIG. 4 shows an enlarged plan view of a part of the second light guide plate 3. The optical path changing optical surface 18 of the second light guide plate 3 is an inclined surface on the incident surface 12 side (right side in FIG. 4) of protrusions having a triangular cross section formed at a constant pitch parallel to the incident surface 12 shown in FIG. A high-angle inclined surface 18a having a high inclination angle θ1 with respect to the emission surface 17 and a low-angle inclination surface 18b having a low inclination angle θ2 with respect to the emission surface 17 and made of an inclined surface on the opposite side.
[0017]
Here, as an example, the inclination angle θ1 of the high-angle inclined surfaces 16a and 18a of the optical path changing optical surfaces 16 and 18 of the first and second light guide plates 2 and 3 with respect to the emission surfaces 15 and 17 is 50 to 70 °. It has become. The inclination angle θ2 of the low-angle inclined surfaces 16b and 18b of the optical path changing optical surfaces 16 and 18 of the first and second light guide plates 2 and 3 with respect to the emission surfaces 15 and 17 is 1 to 5 °.
[0018]
Next, the operation of the first and second light guide plates 2 will be described. In this case, since the first and second light guide plates 2 are disposed symmetrically on both front and rear sides of the liquid crystal display panel 1, the front and rear operations are only reversed. Therefore, as an example, the operation of the first light guide plate 2 will be described, and the operation of the second light guide plate 2 will be described with the same arrows and symbols as in FIG.
[0019]
Now, when the first light source 13 shown in FIG. 1 is turned on, the light emitted from the first light source 13 enters the incident surface 11 of the first light guide plate 2. This incident light typically travels in the first light guide plate 2 as indicated by arrows A and B in FIG. Among these, the light indicated by the arrow A travels in the first light guide plate 2 toward the side where the optical path changing optical surface 16 exists, and is reflected by one of the high-angle inclined surfaces 16 a of the optical path changing optical surface 16. The optical path is changed in a direction substantially perpendicular to the emission surface 15.
[0020]
The light indicated by the arrow B travels in the first light guide plate 2 toward the side where the exit surface 15 exists, is totally reflected at the interface between the exit surface 15 and the air, and then passes through any of the optical path changing optical surfaces 16. The light is reflected by the high-angle inclined surface 16 a and the optical path is changed in a direction substantially perpendicular to the emission surface 15.
[0021]
As described above, the light indicated by the arrows A and B is reflected by one of the high-angle inclined surfaces 16 a of the optical path changing optical surface 16, and the optical path is changed in a direction substantially perpendicular to the emission surface 15. These lights are emitted from the emission surface 15 of the first light guide plate 2 in a direction substantially perpendicular to the emission surface 15.
[0022]
Next, an outline of stereoscopic image display of the liquid crystal display device having the above-described configuration will be described. First, a front display image corresponding to the front display image data is displayed on the front display virtual screen formed on the front surface of the liquid crystal display panel 1, and then the rear display virtual screen formed on the front surface (reflection surface) of the reflector 4. The rear display image corresponding to the rear display image data is displayed. A three-dimensional image is displayed by the afterimage phenomenon between the front display image and the rear display image.
[0023]
Explaining the principle of stereoscopic display in this case, two identical images arranged apart in the depth direction are not seen by the observer as two images having different depths, but are merged and appear as one image. . Further, when the ratio of the luminance of two identical images is changed, the depth position at which one fused image can be seen changes. That is, the depth position at which one fused image can be seen varies slightly depending on individual differences. For example, as shown in FIG. 5, the front display virtual screen (front surface in FIG. 5) formed from the front surface of the liquid crystal display panel 1 is reflected. When the luminance of the front display image is higher than the luminance of the rear display image between the rear display virtual screen (the rear surface in FIG. 5) formed from the front surface of the board 4, the rear display image is closer to the front, and vice versa. Get closer. In this case, the perceived depth is approximately proportional to the luminance ratio between the front and rear surfaces. When a background is displayed on the rear display virtual screen and a person is displayed on the front display virtual screen, a pop-up screen is obtained.
[0024]
Next, the stereoscopic image display of the liquid crystal display device having the above configuration will be described in detail. As shown in FIG. 1, the liquid crystal display panel 1 is driven by the display driving unit 101, and the first light source 13 and the second light source 14 are controlled to be turned on by the light source driving unit 102. The display driving unit 101 displays on the liquid crystal display panel 1 an image corresponding to the image data supplied from the multiplexer 103 that alternately switches and outputs the front display image data and the rear display image data. The display control unit 104 controls the display driving unit 101 and the light source driving unit 102 to match the first display image display and the rear display image display displayed on the liquid crystal display panel 1 in accordance with the switching timing. The lighting of the light source 13 and the second light source 14 is switched.
[0025]
As will be described later, this liquid crystal display device is driven by a field sequential method. First, image data for front display is supplied to the display drive unit 101, and a front display image is displayed on the liquid crystal display panel 1. At this time, the first light source 13 is turned on by being driven by the light source driving unit 102, and the first light source plate 2 is turned on by turning on the first light source 13, for example, as indicated by arrows A and B in FIG. 3. The light exits from the exit surface 15 in a direction substantially perpendicular to the exit surface 15, that is, forward. The emitted light is transmitted through the liquid crystal display panel 1 and the second light guide plate 3, and a front display image corresponding to the front display image displayed on the liquid crystal display panel 1 at that time is displayed. The displayed front display image is observed by the observer as if the front surface of the liquid crystal display panel 1 (near the boundary surface with the second light guide plate 3) is displayed as a front display virtual screen surface.
[0026]
In this case, most of the light transmitted through the second light guide plate 3 and emitted from the optical path changing optical surface 18 passes through the low-angle inclined surface 18a, so that its refraction is small, and the optical path changing optical surface 18 Since the light emitted from the light distribution has a width, the observation from the front direction of the liquid crystal display panel 1 is not greatly affected.
[0027]
Next, the rear display image data is supplied to the display driving unit 101, and the rear display image is displayed on the liquid crystal display panel 1. At this time, the second light source 14 is turned on by being driven by the light source driving unit 102, and the second light guide plate 3 is turned on by turning on the second light source 14 as indicated by arrows A and B in FIG. 4, for example. The light exits from the exit surface 17 in a direction substantially perpendicular to the exit surface 17, that is, backward. The emitted light passes through the liquid crystal display panel 1 and the first light guide plate 2 and is reflected by the reflection plate 4. The reflected light passes through the first light guide plate 2, the liquid crystal display panel 1, and the second light guide plate 3, and a rear display image corresponding to the rear display image displayed on the liquid crystal display panel 1 at that time is displayed. . The displayed rear display image is observed by the observer as the reflection surface of the reflecting plate 4 displayed as a rear display virtual screen surface.
[0028]
Also in this case, most of the light transmitted through the first light guide plate 2 and emitted from the optical path changing optical surface 16 passes through the low-angle inclined surface 16a, so that its refraction is small, and the optical path changing optical surface Since the light emitted from 16 has a wide light distribution, it does not greatly affect the observation of the liquid crystal display panel 1 from the front direction.
[0029]
As described above, when the first light source 13 is turned on, the observer observes the front display image with the front surface of the liquid crystal display panel 1 as the front display virtual screen surface, and when the second light source 14 is turned on, the reflection plate 4 is observed by the observer as a rear display image in which the reflection surface 4 is a rear display virtual screen surface. When the first light source 13 and the second light source 14 blink alternately at high speed, a stereoscopic image is observed by the observer due to the afterimage phenomenon.
[0030]
In this case, the front display image is displayed on the front surface of the liquid crystal display panel 1 by turning on the first light source 13, and then the rear display image is displayed on the reflection surface of the reflector 4 by turning on the second light source 14. Therefore, when observing the front display image, the rear display image is not displayed at all, and when observing the rear display image, the front display image is not displayed at all, thus improving the display quality. Can do. Further, there is no reference point when observing, and therefore it is not necessary to move the neck in the horizontal direction, and it is possible to reduce fatigue.
[0031]
By the way, in the homogeneous alignment type liquid crystal display device, since the response speed is extremely slow, when the first light source 13 and the second light source 14 are alternately blinked at high speed, that is, when driven at a high duty, the frame frequency Becomes low, image flickering occurs, and display of moving images becomes difficult. That is, when gradation display is performed by controlling the transmittance of the liquid crystal 28, the response time when a high write voltage is applied is short, and thus the response speed is fast, but when the write voltage is changed within a low voltage range. The response time is extremely long, and therefore the response speed is extremely slow.
[0032]
This is because the liquid crystal molecules 28a are subjected to forces in a direction opposite to the mutual force between the alignment films 25 and 27 and the liquid crystal molecules 28a (the force for homogeneous alignment) and the force for rising alignment due to the electric field. When a high voltage is applied, the liquid crystal molecules 28a are inclined at a large angle with respect to the alignment films 25 and 27, so that the mutual force becomes relatively weaker than the force for rising and aligning by the electric field. Since the molecules 28a easily move according to the applied voltage, the response speed is fast. However, when the applied voltage is changed in the low voltage range, the liquid crystal molecules 28a are aligned substantially parallel to the film surfaces of the alignment films 25 and 27. For this reason, since the mutual force is relatively stronger than the force for rising and aligning by an electric field, the response speed becomes slow.
[0033]
In the active matrix liquid crystal display device, pixels in each row of the liquid crystal display panel 1 are sequentially selected, and a write voltage corresponding to the write data is applied between the electrodes 23 and 26 in the row for each pixel selection period of each row. However, in such a driving method, the selection period of the pixels in each row must be set to be longer than the longest response time among the response times between the gradations. Can not be driven by.
[0034]
Therefore, in this embodiment, in the homogeneous alignment type active matrix type liquid crystal display device, first, the reset voltage for aligning the liquid crystal molecules 28a so as to rise substantially perpendicularly to the alignment films 25 and 27 between the electrodes 23 and 26. Is applied, and then a write voltage corresponding to the write data is applied between the electrodes 23 and 26, thereby making it possible to respond at a high speed and to drive with a high duty.
[0035]
That is, in the driving method of this embodiment, before applying the write voltage between the electrodes 23 and 26, by applying the reset voltage between the electrodes 23 and 26, the alignment state according to the previously applied write voltage. The liquid crystal molecules 28a are aligned so as to rise substantially perpendicular to the surfaces of the alignment films 25 and 27, the previous writing state is reset, and then a writing voltage corresponding to the writing data is applied between the electrodes 23 and 26. The liquid crystal molecules 28a are caused to behave from the reset state in which the liquid crystal molecules 28a are vertically aligned with respect to the alignment films 25 and 27 to the alignment state corresponding to the current writing voltage.
[0036]
In this case, since the liquid crystal molecules 28a mainly behave in a range where the mutual force with the alignment films 25 and 27 is weak from a state where the liquid crystal molecules 28a are aligned at a large angle with respect to the alignment films 25 and 27, the write voltage is reduced. The response speed when changing in the low voltage range can be sufficiently increased.
[0037]
In this driving method, a reset voltage is applied between the electrodes 23 and 26, and then a write voltage corresponding to the write data is applied between the electrodes 23 and 26. A high voltage for rising and aligning substantially perpendicularly to the surfaces of the alignment films 25 and 27 and the response speed are very fast, so the reset voltage application time may be very short.
[0038]
Next, a specific example of the driving method will be described. FIG. 6 shows waveform diagrams of the applied voltage between the electrodes and the light source drive signal of the pixels in the first and last rows of the liquid crystal display panel as an example of the field sequential drive method. In this case, the first and second light sources 13 and 14 are configured to sequentially emit light of three colors of red, green, and blue.
[0039]
As shown in FIG. 6, the initial stages of the first, second, and third fields for sequentially displaying the images of red, green, and blue in one frame are the initial values of the pixels in each row of the liquid crystal display panel 1, respectively. The write state is set as a reset period for collectively resetting, and after the reset period of each field, write data corresponding to one color of red, green, and blue is sequentially written to the pixels in each row of the liquid crystal display panel 1. A light source lighting period for emitting light of the color corresponding to the write data from the first and second light sources 13 and 14 is secured at the end of each field.
[0040]
In this case, light of three colors of red, green, and blue is sequentially emitted from the first light source 13, and then light of three colors of red, green, and blue is sequentially emitted from the second light source 14, and this is repeated. . The first and second light sources 13 and 14 are the time until the liquid crystal molecules 28a of the pixels in the last row selected at the end of the writing period are aligned according to the writing voltage applied between the electrodes 23 and 26. After the elapse of time, the light turns on and turns off immediately before the reset period of the next field.
[0041]
Then, for each of the first, second, and third fields for sequentially displaying red, green, and blue color images, first, between the electrodes 23 and 26 of the pixels in all rows of the liquid crystal display panel 1. A reset voltage is applied to collectively reset the previous writing state of the pixels in all rows. Next, in the writing period, a writing voltage corresponding to writing data of one color of red, green, and blue is sequentially applied between the electrodes 23 and 26 of the pixels in each row to perform writing to the pixels in each row.
[0042]
Next, when light of a color corresponding to the writing data is emitted from the first light source 13, single color image light of red, green, and blue is emitted from the front surface of the liquid crystal display panel 1 for each field. The observer observes the full-color image light combined with the image light as being displayed on the front display virtual screen formed from the front surface of the liquid crystal display panel 1. Next, when light of the color corresponding to the writing data is emitted from the second light source 14, single color image light of red, green, and blue is emitted from the front surface of the liquid crystal display panel 1 for each field. The full color image light combined with the image light is observed by the observer as being displayed on the rear display virtual screen formed from the front surface of the reflector 4. Then, a stereoscopic image is observed by the observer due to the afterimage phenomenon.
[0043]
Here, as an example, if the number of gate lines is 240 and the application time of the gate signals supplied to the gate lines in each column is 6 μsec, the writing period is 1.44 msec. If the reset period is 0.3 msec and the light source lighting period is less than 1 msec, the period of one field is about 2.74 msec, and it can be driven with a high duty.
[0044]
By the way, the reset voltage is preferably a voltage having the same value as the highest write voltage (the highest write voltage of the plurality of gradations) among the write voltages corresponding to the write data. In this way, the reset voltage can be obtained using the existing write voltage generating means without newly providing the reset voltage generating means.
[0045]
For example, when using a liquid crystal display panel 1 having a color filter provided on the inner surface of the counter substrate 22, a liquid crystal display panel 1 that emits white light is used as the first and second light sources 13 and 14. When the first light source 13 is blinked at the end of one frame and the second light source 14 is blinked at the end of the next frame, a stereoscopic full-color image can be displayed.
[0046]
(Second Embodiment)
FIG. 7 is a plan view of the main part of a liquid crystal display device as a second embodiment of the present invention. In this liquid crystal display device, a first light guide plate 42 is disposed on the rear side of the first liquid crystal display panel 41 disposed perpendicular to the horizontal plane, and a second liquid crystal is disposed on the rear side of the first light guide plate 42. A display panel 43 is disposed, and a second light guide plate 44 is disposed on the rear side of the second liquid crystal display panel 43.
[0047]
First and second light sources 47 and 48 are arranged at positions facing almost the entire entrance surfaces 45 and 46 formed by the right end surfaces of the first and second light guide plates 42 and 44, respectively. A front surface of the first light guide plate 42 (a surface facing the first liquid crystal display panel 41) is an emission surface 49, and a rear surface is an optical path changing optical surface 50. The front surface (the surface facing the second liquid crystal display panel 43) of the second light guide plate 44 is an emission surface 51, and the rear surface is an optical path changing optical surface 52.
[0048]
Next, stereoscopic image display of this liquid crystal display device will be described. First, when the first light source 47 is turned on, light is emitted forward from the emission surface 49 of the first light guide plate 42. The emitted light passes through the first liquid crystal display panel 41, and a front display image corresponding to the front display image displayed on the first liquid crystal display panel 41 at that time is displayed. The displayed front display image is observed by an observer as if the front surface of the first liquid crystal display panel 41 is displayed as a front display virtual screen surface.
[0049]
Thereafter, when the front display image displayed on the first liquid crystal display panel 1 and the first light source 47 are turned off and then the second light source 48 is turned on, the emission surface of the second light guide plate 44 is turned on. Light is emitted forward from 51. This emitted light is transmitted through the second liquid crystal display panel 43, the first light guide plate 42, and the first liquid crystal display panel 41, and at that time, becomes a rear display image displayed on the second liquid crystal display panel 43. A corresponding rear display image is displayed. The displayed rear display image is observed by an observer as if the front surface of the second liquid crystal display panel 43 is displayed as a rear display virtual screen surface.
[0050]
In this way, when the first light source 47 is turned on, the front display image displayed with the front surface of the first liquid crystal display panel 41 as the front display virtual screen surface is observed by the observer, and the second light source 48 is turned on. Then, a rear display image in which the front surface of the second liquid crystal display panel 43 is displayed as a rear display virtual screen surface is observed by an observer. When the first light source 47 and the second light source 48 blink alternately at high speed, a stereoscopic image is observed by the observer due to the afterimage phenomenon.
[0051]
(Third embodiment)
FIG. 8 is a plan view of the main part of a liquid crystal display device as a third embodiment of the present invention. In this liquid crystal display device, the difference from the case shown in FIG. 7 is that the first light guide plate 42 and the first light source 47 are omitted, and the light guide plate 44 and the light source 48 are provided only on the rear side of the second liquid crystal display panel 43. Is the point where
[0052]
Next, stereoscopic image display of this liquid crystal display device will be described. In this case, the light source 48 alternately repeats the first blinking and the second blinking at high speed. When the light source 48 is turned on during the first blinking period, light is emitted forward from the emission surface 51 of the light guide plate 44. The emitted light is transmitted through the second liquid crystal display panel 43 and the first liquid crystal display panel 41, and a front display image corresponding to the front display image displayed on the first liquid crystal display panel 41 at that time is displayed. . The displayed front display image is observed by an observer as if the front surface of the first liquid crystal display panel 1 was displayed as a front display virtual screen surface.
[0053]
On the other hand, when the light source 48 is turned on in the second blinking period, light is emitted forward from the emission surface 51 of the light guide plate 44. The emitted light passes through the second liquid crystal display panel 43 and the first liquid crystal display panel 41, and a rear display image corresponding to the rear display image displayed on the second liquid crystal display panel 43 at that time is displayed. The The displayed rear display image is observed by an observer as if the front surface of the second liquid crystal display panel 43 is displayed as a rear display virtual screen surface.
[0054]
As described above, when the light source 48 is turned on in the first blinking period, the front display image displayed with the front surface of the first liquid crystal display panel 41 as the front display virtual screen surface is observed by the observer, and the second blinking is performed. When the light source 48 is turned on during the period, a rear display image in which the front surface of the second liquid crystal display panel 43 is displayed as a rear display virtual screen surface is observed by an observer. When the light source 48 alternately repeats the first blinking and the second blinking at a high speed, a stereoscopic image is observed by the observer due to the afterimage phenomenon.
[0055]
(Fourth embodiment)
FIG. 9 shows a plan view of the main part of a liquid crystal display device as a fourth embodiment of the present invention. In this liquid crystal display device, a light guide plate 62 is arranged on the rear side of the liquid crystal display panel 61 arranged perpendicular to the horizontal plane, and a reflector plate 63 is arranged on the rear side of the light guide plate 2. A light source 65 is disposed at a position facing substantially the entire incident surface 64 that is the right end surface of the light guide plate 62. The light guide plate 2 has a front surface (a surface facing the liquid crystal display panel 1) as an emission surface 66 and a rear surface as an optical path changing optical surface 67.
[0056]
Next, FIG. 10 shows an enlarged cross-sectional plan view of a part of the liquid crystal display panel 61. The liquid crystal display panel 61 is a simple matrix type, and includes a rear substrate 71 and a front substrate 72 made of a glass substrate or the like. A plurality of rear electrodes 73 made of a transparent conductive material such as ITO are provided to extend in the left-right direction in FIG. 10 at each predetermined location on the inner surface of the rear substrate 71 (the surface on the side facing the front substrate 72). ing. Red, green, and blue color filter elements 74R, 74G, and 74B are provided at predetermined positions on the surface of the rear electrode 73, respectively. An alignment film 75 is provided on the inner surface of the rear substrate 71 including the rear electrode 73 and the color filter elements 74R, 74G, and 74B.
[0057]
A plurality of first and second front electrodes 76a and 76b made of a transparent conductive material such as ITO are provided at predetermined positions on the inner surface of the front substrate 72 (the surface facing the rear substrate 71). Are extended alternately in the direction perpendicular to the plane of the drawing. In this case, the first and second front electrodes 76a and 76b are arranged corresponding to the color filter elements 74R, 74G and 74B. A reflective layer 77 made of a highly reflective metal such as Al is provided between the second front electrode 76 b and the front substrate 72. An alignment film 78 is provided on the inner surface of the front substrate 72 including the first and second front electrodes 76a and 76b.
[0058]
In this case, a transmissive electrode is constituted by the first front electrode 76a, and a reflective electrode is constituted by the second front electrode 76b and the reflective layer 77. The first front electrode 76a is made of a transparent conductive material such as ITO. The second front electrode 76b may be formed of a highly reflective metal such as Al, and the reflective layer 77 may be omitted.
[0059]
The rear substrate 71 and the front substrate 72 are bonded to each other via a sealing material (not shown). A liquid crystal 79 is sealed between the alignment films 75 and 78 of both substrates 71 and 72 inside the sealing material. A polarizing plate 80 is attached to the outer surface of the rear substrate 71. A phase difference plate 81 is attached to the outer surface of the front substrate 72, and a polarizing plate 82 is attached to the outer surface thereof.
[0060]
Next, stereoscopic image display of this liquid crystal display device will be described. In this case, the light source 65 alternately repeats the first blinking and the second blinking at high speed. Then, when the light source 65 is turned on during the first blinking period, light is emitted forward from the emission surface 66 of the light guide plate 62. Part of the emitted light is transmitted through the rear electrode 73 and the first front electrode 76a of the liquid crystal display panel 61, and between the rear electrode 73 of the liquid crystal display panel 61 and the first front electrode 76a at that time. The forward display image is displayed through the liquid crystal 79 driven in accordance with the applied voltage, that is, forward display image data. The displayed front display image is observed by an observer as if the front surface of the liquid crystal display panel 61 is displayed as a front display virtual screen surface.
[0061]
In this case, the remaining part of the emitted light emitted from the emission surface 66 of the light guide plate 62 passes through the rear electrode 73 and the second front electrode 76 b of the liquid crystal display panel 61 and is reflected by the reflective layer 77. . Therefore, if the liquid crystal 79 between the rear electrode 73 and the second front electrode 76b is set in a non-transmissive state, the remaining part of the emitted light is absorbed here, so that the front display light is hardly observed. There is no impact.
[0062]
On the other hand, when the light source 65 is turned on during the second blinking period, light is emitted forward from the emission surface 66 of the light guide plate 62. A part of the emitted light is directly transmitted through the rear electrode 73 and the first front electrode 76a of the liquid crystal display panel 61. Therefore, in this case, if the liquid crystal 79 between the rear electrode 73 and the first front electrode 76a is set in a transmissive state, the observation of the rear display light described later is hardly affected.
[0063]
The remaining part of the emitted light emitted from the emission surface 66 of the light guide plate 62 passes through the rear electrode 73 and the second front electrode 76 b of the liquid crystal display panel 61 and is reflected by the reflective layer 77. The reflected light passes through the second front electrode 76b and the rear electrode 73 of the liquid crystal display panel 61, further passes through the light guide plate 62, and is reflected by the reflection plate 63. The reflected light passes through the rear electrode 73 and the first front electrode 76a of the liquid crystal display panel 61 and is emitted forward of the liquid crystal display panel 61.
[0064]
The emitted light then passes through the liquid crystal 79 driven corresponding to the voltage applied between the rear electrode 73 of the liquid crystal display panel 61 and the second front electrode 76b, that is, the image data for rear display, A rear display image is displayed. The displayed rear display image is observed by the observer as the reflection surface of the reflection plate 63 displayed as the rear display virtual screen surface.
[0065]
Thus, when the light source 65 is turned on during the first blinking period, the front display image displayed with the front surface of the liquid crystal display panel 61 as the front display virtual screen surface is observed by the observer, and the light source is displayed during the second blinking period. When 65 is turned on, the rear display image in which the reflection surface of the reflection plate 63 is used as the rear display virtual screen surface is observed by the observer. When the light source 65 alternately repeats the first blinking and the second blinking at a high speed, a stereoscopic image is observed by the observer due to the afterimage phenomenon.
[0066]
(Other embodiments)
For example, in FIG. 7, as shown in FIG. 1, the reflection plate 4 is disposed behind the second light guide plate 44, and the first light guide plate 42 and the first light source 47 are connected to the first display panel 41. It is also possible to combine the above-described embodiments as appropriate, such as disposing them in front of each other. Further, in the cases shown in FIGS. 1 and 9, concave mirrors may be used as the reflecting plates 4 and 63. In this case, when the background is displayed on the virtual screen for rear display made of the concave surface of the concave mirror and the person is displayed on the virtual screen for front display made of the front surface of the liquid crystal display panels 1 and 61, the background is slightly parallax. Therefore, it is possible to obtain a screen that pops out with good separation before and after. In each of the above embodiments, the light source device including the light guide plate and the light source may be a flat light source panel formed of, for example, a transparent organic EL (electroluminescence).
[0067]
【The invention's effect】
As described above, according to the present invention, a three-dimensional image is displayed due to an afterimage phenomenon between the front display light and the rear display light obtained alternately, so when displaying with the front display light, No rear display light is generated, and no front display light is generated at the time of display with the rear display light, so that the display quality can be improved. Further, there is no reference point when observing, and therefore it is not necessary to move the neck in the horizontal direction, and it is possible to reduce fatigue.
[Brief description of the drawings]
FIG. 1 is a plan view of a main part of a liquid crystal display device as a first embodiment of the invention.
FIG. 2 is an enlarged cross-sectional plan view of a part of the liquid crystal display panel shown in FIG.
FIG. 3 is an enlarged plan view of a part of the first light guide plate shown in FIG. 1;
4 is an enlarged plan view of a part of a second light guide plate shown in FIG.
FIG. 5 is a diagram for explaining a depth perceived in a stereoscopic display.
FIG. 6 is a waveform diagram of an inter-electrode applied voltage and a light source driving signal for pixels in the first row and the last row of a liquid crystal display panel according to an example of a field sequential driving method.
FIG. 7 is a plan view of a main part of a liquid crystal display device as a second embodiment of the invention.
FIG. 8 is a plan view of a main part of a liquid crystal display device as a third embodiment of the invention.
FIG. 9 is a plan view of a main part of a liquid crystal display device as a fourth embodiment of the invention.
10 is an enlarged cross-sectional plan view of a part of the liquid crystal display panel shown in FIG.
[Explanation of symbols]
1 LCD panel
2 First light guide plate
3 Second light guide plate
4 reflectors
13 First light source
14 Second light source

Claims (13)

One or more display panels for displaying a front display image and a rear display image, one or more light source panels for irradiating light to the display panel, and driving the display panel to alternate the front display image and the rear display image Display drive means to be displayed on the display panel, and light source control means for turning on the light source panel according to the display of the front display image and the rear display image of the display panel, and a luminance difference between the front display image and the rear display image. A display device characterized in that a stereoscopic image can be visually recognized by being attached to. 2. The display device according to claim 1, wherein the display panel is driven by a field sequential method. 2. The display device according to claim 1, wherein the display panel is a homogeneously oriented liquid crystal display panel. 2. The display device according to claim 1, wherein the light source panel includes a light guide plate and a light source disposed on one end surface of the light guide plate. 5. The light guide plate according to claim 4, wherein the light guide plate has an optical path changing optical surface that refracts the light emitted from the light source toward the emission surface side on a surface opposite to the emission surface that emits light. Characteristic display device. In the invention according to claim 1, the light source panel includes a first light source panel disposed in front of the display panel, and a second light source panel disposed in the rear of the display panel, A reflective layer is disposed behind the second light source panel, the second light source panel is turned on while the display panel is displaying a front display image, and the second light source panel is displayed while the display panel is displaying a rear display image. A light source panel is turned on and reflected by the reflection layer. 7. The display device according to claim 6, wherein the reflective layer is a concave mirror. In the first aspect of the present invention, the display panel includes a first display panel that displays a front display image, and a second display panel that is disposed behind the display panel and displays a rear display image. Display device. 9. The light source panel according to claim 8, wherein the light source panel is disposed between the first display panel and the second display panel, and is turned on while a front display image is displayed on the first display panel. 1. A display device comprising: one light source panel; and a second light source panel that is turned on while a rear display image is displayed on the second display panel. 9. The invention according to claim 8, wherein the first display panel, the second display panel, and the light source panel are arranged in this order, a front display image is displayed on the first display panel, and the second display is displayed. A display device, wherein a rear display image is displayed on a panel, and the light source panel is turned on while a front display image and a rear display image are displayed. In the invention according to claim 1, each of the display panels includes a liquid crystal display panel having substrates opposite to each other having electrodes on the inner surface, and one substrate of the liquid crystal display panel is adjacent to the electrodes. A display device, characterized in that a reflective electrode is provided. 12. The invention according to claim 11, wherein the display driving means corresponds to the reflective electrode while displaying one of the front display image and the rear display image on the liquid crystal display panel in an area corresponding to the electrode adjacent to the reflective electrode. The region to be transmitted is made non-transmissive, and the region corresponding to the electrode adjacent to the reflective electrode is made transparent while the other of the front display image and the rear display image is displayed on the liquid crystal display panel in the region corresponding to the reflective electrode. A display device characterized in that the liquid crystal display panel is driven and controlled. The display device according to claim 12, wherein a reflective layer is disposed behind the light source panel.

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