Stereoscopic display system and liquid crystal shutter device

Abstract

To provide a stereoscopic display system and a liquid crystal shutter device, which can prevent a delay in the timing of a change in a polarization state of light by the liquid crystal shutter device with respect to the display timing of a display panel.SOLUTION: A stereoscopic display system 100 comprises a display panel 2 and a liquid crystal shutter device 1. The liquid crystal shutter device 1 includes a liquid crystal layer 30, a segment electrode 11, a counter electrode 21, an auxiliary electrode 23, an insulating layer 24, and a driving circuit 3. The driving circuit 3 applies a driving voltage to the segment electrode 11 in synchronization with the switching of the display of the display panel 2. Also, the driving circuit 3 applies a voltage having an opposite phase to the voltage applied to the segment electrode 11 to the auxiliary electrode 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a stereoscopic display system and a liquid crystal shutter device. [Background technology]

[0002] Conventionally, stereoscopic display systems and liquid crystal shutter devices are known. Such a stereoscopic display system is disclosed in, for example, Patent Document 1. The stereoscopic display system of Patent Document 1 includes a display panel, a liquid crystal shutter device, and polarized glasses. The display panel alternately displays left-eye images and right-eye images in a time-division manner. The liquid crystal shutter device converts display light into left-handed circularly polarized light or right-handed circularly polarized light in synchronization with the display periods of the left-eye images and right-eye images. The polarized glasses block the right-eye image and deliver only the left-eye image to the left eye of an observer wearing the polarized glasses, and block the left-eye image and deliver only the right-eye image to the observer's right eye. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-235208 A Summary of the Invention [Problem to be solved by the invention]

[0004] A conventional liquid crystal shutter device such as that described in Patent Document 1 includes a liquid crystal layer, and a first electrode and a second electrode sandwiching the liquid crystal layer. In the liquid crystal shutter device, a voltage is applied to the first electrode and the second electrode is set to a fixed potential, thereby generating a potential difference on both sides of the liquid crystal layer and driving the liquid crystal in the liquid crystal layer.

[0005] However, conventional liquid crystal shutter devices have resistance in the wiring for supplying a voltage from a power source to the first electrode, and resistance in the wiring and common transfer material for connecting the second electrode to a fixed potential. Therefore, when a voltage is supplied to the first electrode, the potential of the second electrode changes from the fixed potential due to the resistance of the wiring and the resistance of the common transfer material, and the electric capacitance of the liquid crystal layer, and the time constant of the waveform of the voltage applied to the liquid crystal layer (the potential difference between the first electrode and the second electrode) becomes large. As a result, there is a problem that the switching of the polarization state of light by the liquid crystal shutter device is delayed with respect to the display timing of the display panel.

[0006] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a stereoscopic display system and a liquid crystal shutter device that can prevent a delay in the timing of the change in the polarization state of light by the liquid crystal shutter device relative to the display timing of the display panel. [Means for solving the problem]

[0007] In order to solve the above problem, a stereoscopic display system according to a first aspect of the present disclosure includes a display panel that alternately displays an image for the left eye and an image for the right eye, and a liquid crystal shutter device that switches between a state in which light incident from the display panel is changed to output light having a first polarization state and a state in which light incident from the display panel is changed to output light having a second polarization state, and the liquid crystal shutter device has a first electrode, a second electrode connected to a fixed potential, a liquid crystal layer disposed between the first electrode and the second electrode, and a liquid crystal shutter device that changes the polarization state of the output light. a drive circuit that applies to the first electrode either a first voltage that changes the polarization state of the emitted light to the first polarization state or a second voltage that changes the polarization state of the emitted light to the second polarization state, the drive circuit switching the voltage applied to the first electrode between the first voltage and the second voltage in synchronization with switching of the display of the left eye image and the right eye image by the display panel, and a third electrode arranged on the opposite side of the second electrode to the side on which the liquid crystal layer is arranged, and the drive circuit applies to the third electrode a third voltage having an opposite phase to the voltage applied to the first electrode.

[0008] A liquid crystal shutter device according to a second aspect is a liquid crystal shutter device that switches between a state in which light incident from a display panel that alternately displays left-eye images and right-eye images is changed into output light having a first polarization state and a state in which light incident from the display panel is changed into output light having a second polarization state and output, and includes a first electrode, a second electrode connected to a fixed potential, a liquid crystal layer disposed between the first electrode and the second electrode, a first voltage that changes the polarization state of the output light to the first polarization state, and a drive circuit that applies to the first electrode either a first voltage or a second voltage that changes the polarization state of the emitted light to the second polarization state, and that switches the voltage to be applied to the first electrode between the first voltage and the second voltage in synchronization with switching of the display of the left eye image and the right eye image by the display panel, and a third electrode that is arranged on the opposite side of the second electrode to the side on which the liquid crystal layer is arranged, and the drive circuit applies to the third electrode a third voltage having an opposite phase to the voltage applied to the first electrode. Effect of the Invention

[0009] Here, the potential of the second electrode changes with respect to a fixed potential due to the application of the first voltage to the first electrode. In contrast, according to the above configuration, the third voltage having a phase opposite to that of the voltage applied to the first electrode is applied to the third electrode. This allows the potential of the second electrode to be changed in a phase opposite to that of the change in potential due to the first voltage. As a result, the change in potential due to the third voltage cancels out the change in potential due to the first voltage, so that it is possible to prevent an increase in the time constant of the waveform of the voltage applied to the liquid crystal layer (dulling of the waveform). This prevents a delay in the timing at which the polarization state of the light emitted from the liquid crystal shutter device is switched relative to the timing at which the voltage applied to the first electrode is switched between the first voltage and the second voltage. Furthermore, the timing at which the voltage applied to the first electrode is switched between the first voltage and the second voltage is synchronized with the timing at which the image for the left eye and the image for the right eye are switched (display timing), so it is possible to prevent a delay in the timing at which the polarization state of the light is changed by the liquid crystal shutter device relative to the display timing of the display panel. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a stereoscopic display system 100 in the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the liquid crystal shutter device 1 according to the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing the configuration of the connection portion between the counter electrode 21 and the wiring portion 40 of the liquid crystal shutter device 1 according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of the connection portion between the auxiliary electrode 23 and the wiring portion 40 of the liquid crystal shutter device 1 according to the first embodiment. [Diagram 5] FIG. 5 is a plan view of the liquid crystal shutter device 1 according to the first embodiment. [Figure 6] FIG. 6 is a plan view of the auxiliary electrode 23. As shown in FIG. [Figure 7] FIG. 7 is a schematic diagram for explaining the capacitances Cs and CL. [Figure 8] FIG. 8 is a circuit diagram showing a schematic diagram of the electrical relationship between the segment electrode 11, the counter electrode 21, and the auxiliary electrode 23. As shown in FIG. [Figure 9] FIG. 9 is a timing chart for explaining the relationship between the voltage applied to each electrode and the polarization direction of the light emitted from the liquid crystal shutter device 1. As shown in FIG. [Figure 10] FIG. 10 is a diagram showing waveforms of voltages applied to the segment electrodes, the counter electrode, and the liquid crystal layer at the time of transition from period T2 to period T3 in a stereoscopic display system according to a comparative example. [Figure 11] FIG. 11 is a diagram showing waveforms of voltages applied to the segment electrode 11, the counter electrode 21, the auxiliary electrode 23, and the liquid crystal layer 30 at the time of transition from period T2 to period T3 in the stereoscopic display system 100 according to the first embodiment. [Figure 12] FIG. 12 is a diagram showing changes in voltage applied to the liquid crystal layer in each of the first to fifth embodiments. [Figure 13] FIG. 13 is a plan view of a liquid crystal shutter device 301 according to the second embodiment. [Figure 14] FIG. 14 is a cross-sectional view of a liquid crystal shutter device 301 according to the second embodiment. [Figure 15] FIG. 15 is a diagram showing a liquid crystal shutter device 401 according to a first modified example of the first and second embodiments. [Figure 16] FIG. 16 is a diagram showing a liquid crystal shutter device 501 according to a second modified example of the first and second embodiments. [Figure 17] FIG. 17 is a diagram showing an auxiliary electrode 623 according to a third modification of the first and second embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described based on the drawings. Note that the present disclosure is not limited to the following embodiments, and appropriate design changes can be made within the scope of satisfying the configuration of the present disclosure. In addition, in the following description, the same parts or parts having similar functions are commonly used with the same reference numerals in different drawings, and repeated explanations thereof will be omitted. In addition, each configuration described in the embodiment and the modified example may be appropriately combined or changed within the scope of the gist of the present disclosure. In addition, in order to make the description easier to understand, in the drawings referred to below, the configuration is shown in a simplified or schematic manner, and some components are omitted. In addition, the dimensional ratio between the components shown in each figure does not necessarily indicate the actual dimensional ratio.

[0012] [First embodiment] Fig. 1 is a schematic diagram showing the configuration of a stereoscopic display system 100 in the first embodiment. As shown in Fig. 1, the stereoscopic display system 100 is a system (apparatus) that allows a user wearing polarized glasses 200 to visually recognize a stereoscopic image.

[0013] The stereoscopic display system 100 alternately switches between displaying an image for the left eye and an image for the right eye. The polarization state of the image for the left eye output from the stereoscopic display system 100 is different from that of the image for the right eye. For example, the light output from the stereoscopic display system 100 is linearly polarized, and the polarization direction of the image for the left eye is different from that of the image for the right eye by 90 degrees. In the first embodiment, one of the polarization directions of the image for the left eye and the image for the right eye is −45 degrees, and the other is +45 degrees, but one of the polarization directions of the image for the left eye and the image for the right eye may be 0 degrees, and the other may be 90 degrees. A polarizing film 201 that transmits light in the polarization direction of the image for the left eye and blocks light in the polarization direction of the image for the right eye is disposed in the left eye rim of the polarizing glasses 200. Also, a polarizing film 202 that transmits light in the polarization direction of the image for the right eye and blocks light in the polarization direction of the image for the left eye is disposed in the right eye rim of the polarizing glasses 200. That is, stereoscopic display system 100 is an active retarder type stereoscopic image display system (3D image display system).

[0014] As shown in Fig. 1, the stereoscopic display system 100 includes a liquid crystal shutter device 1, a display panel 2, a liquid crystal shutter drive circuit 3 (hereinafter referred to as "drive circuit 3"), and a display panel drive circuit 4 (hereinafter referred to as "drive circuit 4"). In Fig. 1, the liquid crystal shutter device 1, the display panel 2, the drive circuit 3, and the drive circuit 4 are shown separated from each other for the sake of explanation, but at least two of the liquid crystal shutter device 1, the display panel 2, the drive circuit 3, and the drive circuit 4 may be integrally arranged in contact with each other. For example, the liquid crystal shutter device 1, the display panel 2, the drive circuit 3, and the drive circuit 4 may be arranged in a housing not shown.

[0015] The display panel 2 alternately displays an image for the left eye and an image for the right eye. The display panel 2 alternately displays an image for the left eye and an image for the right eye for each frame. This is not limiting, and the display panel 2 may be configured to alternately display an image for the left eye and an image for the right eye for each predetermined period (for each plurality of frames). The display panel 2 is configured as a liquid crystal display panel or an organic EL panel.

[0016] The drive circuit 4 controls the driving of the display panel 2 by supplying drive signals (gate signals and source signals) to the display panel 2. The drive circuit 4 also updates images on the display panel 2 at a predetermined display timing (refresh rate). The drive circuit 4 then transmits a synchronization signal to the drive circuit 3 in synchronization with the display timing.

[0017] (Configuration of liquid crystal shutter device 1) FIG. 2 is a cross-sectional view of the liquid crystal shutter device 1 according to the first embodiment. FIG. 3 is a cross-sectional view showing the configuration of the connection portion between the counter electrode 21 and the wiring section 40 of the liquid crystal shutter device 1 according to the first embodiment. FIG. 4 is a cross-sectional view showing the configuration of the connection portion between the auxiliary electrode 23 and the wiring section 40 of the liquid crystal shutter device 1 according to the first embodiment. FIG. 5 is a plan view of the liquid crystal shutter device 1 according to the first embodiment. FIG. 6 is a plan view of the auxiliary electrode 23. The liquid crystal shutter device 1 is a panel that switches between a state in which the light incident from the display panel 2 is changed to an outgoing light having a polarization direction of −45 degrees and outputted, and a state in which the light incident from the display panel 2 is changed to an outgoing light having a polarization direction of +45 degrees and outputted. The liquid crystal shutter device 1 includes a first substrate 10 and a second substrate 20 arranged opposite to the first substrate 10. The liquid crystal shutter device 1 also includes a plurality of segment electrodes 11, an alignment film 12, a plurality of counter electrodes 21, an alignment film 22, a plurality of auxiliary electrodes 23, an insulating layer 24, a liquid crystal layer 30, a seal section 31, and a wiring section 40. The wiring section 40 is, for example, a flexible printed circuit board, and has a plurality of wirings (not shown) provided therein. The first substrate 10 and the second substrate 20 are, for example, a glass substrate or a resin substrate that transmits light. The plurality of segment electrodes 11 are an example of a "plurality of first electrode portions." The plurality of counter electrodes 21 are an example of a "plurality of second electrode portions." The plurality of auxiliary electrodes 23 are an example of a "plurality of third electrode portions."

[0018] As shown in FIG. 2, the segment electrodes 11 are disposed on the first substrate 10. The segment electrodes 11 are connected to the drive circuit 3 via the wiring section 40. The alignment film 12 covers an area Ra (see FIG. 5) of the segment electrodes 11 that transmits light from the display panel 2 and causes the light to exit from the liquid crystal shutter device 1. The alignment film 12 is disposed between the segment electrodes 11 and the liquid crystal layer 30. The alignment film 12 transmits light having a predetermined polarization direction. The segment electrodes 11 are made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The segment electrodes 11 may be made of a metal conductive material configured in a mesh shape.

[0019] As shown in FIG. 3, the counter electrodes 21 are disposed on the second substrate 20. The counter electrodes 21 are disposed at positions overlapping with any one of the segment electrodes 11 in a plan view of the liquid crystal shutter device 1 (viewed in the Z direction). The counter electrodes 21 are connected to a wiring section 40, a part of which is disposed on the first substrate 10, via a seal section 31 (common transfer) disposed between the first substrate 10 and the second substrate 20. The seal section 31 includes a seal material 31a that seals the liquid crystal layer 30 between the first substrate 10 and the second substrate 20, and conductive beads 31b contained in the seal material 31a. The counter electrodes 21 are connected to the wiring section 40 disposed on the first substrate 10 side via the conductive beads 31b. The counter electrodes 21 are connected to a ground (GND) having a fixed potential via the wiring section 40. The alignment film 22 covers a region Ra (see FIG. 5) of the counter electrodes 21. The alignment film 22 is disposed between the counter electrode 21 and the liquid crystal layer 30. The alignment film 22 transmits light having a predetermined polarization direction. The counter electrode 21 is disposed opposite the plurality of segment electrodes 11 via the liquid crystal layer 30. The counter electrode 21 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The counter electrode 21 may be made of a metallic conductive material or a transparent conductive material configured in a mesh shape.

[0020] In the first embodiment, as shown in FIG. 4, the auxiliary electrode 23 is disposed at a position in the Z direction with respect to the counter electrode 21. That is, the auxiliary electrode 23 is disposed on the opposite side of the counter electrode 21 from the side where the liquid crystal layer 30 is disposed. The auxiliary electrode 23 is disposed between the counter electrode 21 and the second substrate 20. The insulating layer 24 is disposed between the counter electrode 21 and the auxiliary electrode 23 in the normal direction. As a result, the auxiliary electrode 23 is disposed opposite the counter electrode 21 via the insulating layer 24. In the first embodiment, the auxiliary electrode 23 is disposed within the region Ra (see FIG. 5). The auxiliary electrode 23 is disposed at a position overlapping with any of the multiple counter electrodes 21 in a plan view. The multiple auxiliary electrodes 23 are connected to a wiring section 40, a part of which is disposed on the first substrate 10, via a seal section 31 (common transfer) disposed between the first substrate 10 and the second substrate 20. The multiple auxiliary electrodes 23 are connected to the drive circuit 3 via the wiring section 40.

[0021] As shown in Fig. 6, in the first embodiment, each of the auxiliary electrodes 23 is configured in a mesh shape. For example, the auxiliary electrodes 23 have a structure in which a plurality of linear conductors aligned along the arrangement direction of pixels (not shown) of the display panel 2 (the vertical and horizontal directions of the paper surface in Fig. 6) intersect. The auxiliary electrodes 23 are made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The auxiliary electrodes 23 may be made of a metallic conductive material. The insulating layer 24 is made of an insulating inorganic film or an insulating organic film.

[0022] FIG. 7 is a schematic diagram for explaining capacitances Cs and CL. FIG. 8 is a circuit diagram showing the electrical relationship between the segment electrode 11, the counter electrode 21, and the auxiliary electrode 23. As shown in FIG. 8, a wiring resistance R1 exists between the segment electrode 11 and the drive circuit 3. A wiring resistance R2a and a resistance R2b due to common transfer exist between the counter electrode 21 and the ground (GND). A wiring resistance R3a and a resistance R3b due to common transfer exist between the auxiliary electrode 23 and the drive circuit 3. The liquid crystal shutter device 1 also includes a segment electrode input terminal 5a, a counter electrode input terminal 5b, and an auxiliary electrode input terminal 5c. The liquid crystal shutter drive circuit 3 supplies a voltage to the segment electrode 11 by inputting a voltage to the segment electrode input terminal 5a. The liquid crystal shutter drive circuit 3 supplies a voltage to the auxiliary electrode 23 by inputting a voltage to the auxiliary electrode input terminal 5c. The counter electrode input terminal 5b is connected to the ground (GND). 7, the plurality of counter electrodes 21 form electric capacitances CL with the plurality of segment electrodes 11. Moreover, the auxiliary electrode 23 forms electric capacitances Cs with the counter electrode 21.

[0023] (Configuration of liquid crystal shutter drive circuit 3) Fig. 9 is a timing diagram for explaining the relationship between the voltage applied to each electrode and the polarization direction of light emitted from the liquid crystal shutter device 1. Note that in Fig. 9, for the sake of explanation, the voltage waveform is simplified and depicted as a rectangular wave.

[0024] As shown in FIG. 9, the drive circuit 3 applies a voltage to the segment electrode 11 during a period in which the display panel 2 displays an image for the left eye (periods T2, T4, and T6 in FIG. 9) so that the polarization direction of the light emitted from the liquid crystal shutter device 1 becomes −45 degrees. For example, the drive circuit 3 inputs a voltage V1H to the segment electrode input terminal 5a during the period T2, thereby changing the absolute value of the voltage applied to the liquid crystal layer 30 from a state equal to or lower than the off threshold Voff to a state equal to or higher than the on threshold Von due to the potential difference between the segment electrode 11 and the counter electrode 21. Then, the drive circuit 3 applies a voltage to the segment electrode 11 during a period in which the display panel 2 displays an image for the right eye (periods T1, T3, and T5 in FIG. 9) so that the polarization direction of the light emitted from the liquid crystal shutter device 1 becomes +45 degrees. For example, the drive circuit 3 sets the potential of the segment electrode input terminal 5a to the ground (GND) potential, thereby reducing the potential difference between the segment electrode 11 and the counter electrode 21, and changing the absolute value of the voltage applied to the liquid crystal layer 30 from a state equal to or greater than the on-threshold Von to a state equal to or less than the off-threshold Voff. The light of the left eye image having a polarization direction of -45 degrees emitted from the liquid crystal shutter device 1 passes through the polarizing film 201 of the polarized glasses 200, and the light of the right eye image having a polarization direction of +45 degrees passes through the polarizing film 202 of the polarized glasses 200. The drive circuit 3 then repeats the above operations, allowing the viewer wearing the polarized glasses 200 to view a stereoscopic image (stereoscopic video).

[0025] Here, as shown in FIG. 9, in the first embodiment, the drive circuit 3 applies to the auxiliary electrode 23 a voltage having an opposite phase to the voltage applied to the segment electrode 11. For example, during a period in which a voltage V1H having a positive polarity is input to the segment electrode input terminal 5a (periods T2 and T6 in FIG. 9), the drive circuit 3 inputs a voltage V3L having a negative polarity to the auxiliary electrode input terminal 5c. Also, during a period in which a voltage V1L having a negative polarity is input to the segment electrode input terminal 5a (period T4 in FIG. 9), the drive circuit 3 inputs a voltage V3H having a positive polarity to the auxiliary electrode input terminal 5c. Also, during a period in which the potential of the segment electrode input terminal 5a is set to the ground (GND) potential (periods T3 and T5 in FIG. 9), the drive circuit 3 sets the potential of the auxiliary electrode input terminal 5c to the ground (GND) potential. The absolute value Vc of the voltage value of the voltage V3L is equal to the absolute value of the voltage value of the voltage V3H. Moreover, the absolute value Vs of the voltage value of the driving voltage V1H is equal to the absolute value of the voltage value of the driving voltage V1L. In the first embodiment, the absolute value Vc is smaller than the absolute value Vs. Note that the absolute value Vc may be equal to the absolute value Vs.

[0026] In addition, if the capacitance between the segment electrode 11 and the counter electrode 21 is CL, and the capacitance between the counter electrode 21 and the auxiliary electrode 23 is Cs, then the absolute value Vc satisfies the following formula (1). Vc≦Vs × (CL / Cs) (1)

[0027] (Comparison Results Between First Embodiment and Comparative Example) Next, a comparison result of the electrode waveforms between the stereoscopic display system 100 according to the first embodiment and a stereoscopic display system according to a comparative example will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a diagram showing waveforms of voltages applied to the segment electrodes, counter electrodes, and liquid crystal layer at the time of transition from period T2 to period T3 in the stereoscopic display system according to the comparative example. Fig. 11 is a diagram showing waveforms of voltages applied to the segment electrodes 11, counter electrodes 21, auxiliary electrodes 23, and liquid crystal layer 30 at the time of transition from period T2 to period T3 in the stereoscopic display system 100 according to the first embodiment. Fig. 11 shows an example of each waveform inside the liquid crystal shutter device 1 (inside the panel).

[0028] The stereoscopic display system according to the comparative example is not provided with an auxiliary electrode 23. The other configurations (configurations of the display panel, segment electrodes, counter electrodes, etc.) of the stereoscopic display system according to the comparative example are the same as those of the first embodiment. Note that the stereoscopic display system according to the comparative example is illustrated to explain the effects of the stereoscopic display system 100 according to the first embodiment, and does not represent the prior art.

[0029] As shown in FIG. 10, in the stereoscopic display system of the comparative example, a driving voltage V1H is supplied to the segment electrodes during a period T2. The driving voltage V1H is a positive voltage with respect to the ground potential. During the period T2, the potential of the counter electrode becomes equal to the ground potential. Then, in the stereoscopic display system of the comparative example, during a period T3 following the period T2, the potential of the segment electrodes becomes equal to the ground potential. Here, as the potential of the segment electrodes changes from V1H to the ground potential, the potential of the counter electrodes changes to a negative potential with respect to the ground potential (fixed potential). As a result, the rate at which the voltage applied to the liquid crystal layer decreases is slowed (the waveform becomes dull), and the time required for the voltage to decrease below the off threshold Voff is increased.

[0030] As shown in FIG. 11, in the first embodiment, the drive circuit 3 supplies a drive voltage V1H to the segment electrode 11 in a period T2. Also, the drive circuit 3 applies a voltage V3L having a polarity opposite to that of the voltage applied to the segment electrode 11 to the auxiliary electrode 23 in the period T2. The potential of the counter electrode 21 becomes equal to the ground potential. Then, the drive circuit 3 makes the potential of the segment electrode 11 equal to the ground potential in the period T3. Also, the drive circuit 3 makes the potential of the segment electrode 11 equal to the ground potential in the period T3. That is, in the first embodiment, the drive circuit 3 applies a voltage having a phase opposite to that of the voltage applied to the segment electrode 11 to the auxiliary electrode 23. Here, as the potential of the segment electrode 11 becomes the ground potential from V1H, the potential of the counter electrode 21 changes to a negative potential with respect to the ground potential (fixed potential). Furthermore, the potential of the portion of the auxiliary electrode 23 that overlaps with the segment electrode 11 in a plan view also becomes lower than the voltage V3L due to the change in the potential of the segment electrode 11.

[0031] However, in the first embodiment, a voltage having a phase opposite to that of the voltage input to the segment electrode input terminal 5a is input to the auxiliary electrode input terminal 5c (see FIG. 9). This makes it possible to change the potential of the counter electrode 21 in a phase opposite to that of the potential change caused by the segment electrode 11. As a result, as shown in FIG. 11, in the liquid crystal shutter device 1 (inside the panel), the potential change caused by the auxiliary electrode 23 cancels out the potential change caused by the segment electrode 11, so that the potential change of the counter electrode 21 can be suppressed. That is, according to the first embodiment, the rate at which the voltage applied to the liquid crystal layer 30 decreases is higher (waveform dulling is prevented) than in the stereoscopic display system according to the comparative example, and the time until the voltage falls below the off threshold Voff can be shortened. As a result, it is possible to prevent the timing of changing the polarization direction of light by the liquid crystal shutter device 1 from being delayed with respect to the display timing of the display panel 2.

[0032] (Example according to the first embodiment) Next, first to fifth examples according to the first embodiment will be described with reference to Fig. 12. The stereoscopic display system according to the first example is a stereoscopic display system 100 in which the capacitance Cs1 is set to capacitance CL (Cs1 = CL), and the absolute value Vc1 of the voltage value applied to the auxiliary electrode 23 is set to be equal to the absolute value Vs of the voltage value applied to the segment electrode 11 (Vc1 = Vs). The stereoscopic display system according to the second example is a stereoscopic display system 100 in which the capacitance Cs2 is set to twice the capacitance CL (Cs2 = 2 x CL), and the absolute value Vc2 of the voltage value applied to the auxiliary electrode 23 is set to 0.5 times the absolute value Vs of the voltage value applied to the segment electrode 11 (Vc2 = Vs x 0.5). The stereoscopic display system according to the third embodiment is a stereoscopic display system 100 in which the capacitance Cs3 is four times the capacitance CL (Cs3=4×CL), and the absolute value Vc3 of the voltage applied to the auxiliary electrode 23 is 0.25 times the absolute value Vs of the voltage applied to the segment electrode 11 (Vc3=Vs×0.25). The stereoscopic display system according to the fourth embodiment is a stereoscopic display system 100 in which the capacitance Cs4 is ten times the capacitance CL (Cs4=10×CL), and the absolute value Vc4 of the voltage applied to the auxiliary electrode 23 is 0.1 times the absolute value Vs of the voltage applied to the segment electrode 11 (Vc4=Vs×0.1). The stereoscopic display system according to the fifth embodiment is a stereoscopic display system 100 in which the capacitance Cs5 is set to capacitance CL (Cs5=CL), and the absolute value Vc5 of the voltage applied to the auxiliary electrode 23 is set to 0.75 times (Vc5=Vs×0.75) the absolute value Vs of the voltage applied to the segment electrode 11. For example, CL=5 μF and Vs=10 V can be used, but the present disclosure is not limited to these numerical examples.

[0033] FIG. 12 is a diagram showing the change in voltage applied to the liquid crystal layer in each of the first to fifth examples. FIG. 12 shows the measurement results of the voltage value applied to the liquid crystal layer in the first to fifth examples when the period T2 is changed to the period T3. In the first example among the first to fifth examples, the voltage value of the voltage applied to the liquid crystal layer became lower than the off threshold Voff at the earliest point after the start of the period T3 (the time constant became smaller). In addition, the order from the smallest time constant is the first example, the second example, the fifth example, the third example, and the fourth example. In addition, in the fifth example among the first to fifth examples, the magnitude (overshoot voltage) at which the voltage value applied to the liquid crystal layer exceeds the ground potential after the start of the period T3 is the smallest. In addition, in the fifth example, the order from the smallest overshoot voltage is the fifth example, the fourth example, the third example, the second example, and the first example.

[0034] From the results of Fig. 12, it was found that the smaller the capacitance Cs and the larger the absolute value Vc, the smaller the time constant of the voltage applied to the liquid crystal layer. It was also found that the smaller the absolute value Vc, the smaller the overshoot voltage. It was also found that the fifth embodiment is an embodiment that can reduce the overshoot voltage while reducing the time constant of the voltage applied to the liquid crystal layer.

[0035] [Second embodiment] Next, the configuration of a liquid crystal shutter device 301 according to a second embodiment will be described with reference to Fig. 13 and Fig. 14. The same components as those in the first embodiment are given the same reference numerals and will not be described. Fig. 13 is a plan view of the liquid crystal shutter device 301 of the second embodiment. Fig. 14 is a cross-sectional view of the liquid crystal shutter device 301 of the second embodiment.

[0036] As shown in FIG. 13, the liquid crystal shutter device 301 according to the second embodiment includes an auxiliary electrode 323. The auxiliary electrode 323 is disposed outside the region Ra from which the liquid crystal shutter device 301 emits light in a plan view. For example, the auxiliary electrode 323 is disposed in the frame region Rb. This makes it possible to prevent the auxiliary electrode 323 from blocking light from the display panel 2 according to the second embodiment. This makes it possible to improve the light transmittance of the liquid crystal shutter device 301. The auxiliary electrode 323 is formed in a U-shape in a plan view. For example, a wiring portion (not shown) is disposed at the bottom of the U-shaped auxiliary electrode 323 (below the paper surface of FIG. 13). The auxiliary electrode 323 is connected to the drive circuit 3 via the wiring portion. The auxiliary electrode 323 is made of, for example, a metal material (any of copper, silver, gold, aluminum, etc.).

[0037] As shown in FIG. 14, the auxiliary electrode 323 is disposed opposite to the counter electrode 21 via an insulating layer 324. The drive circuit 3 (see FIG. 1) applies a voltage having an opposite phase to the voltage applied to the segment electrode 11 to the auxiliary electrode 323. This suppresses the change in the potential of the counter electrode 21, thereby shortening the time required for the voltage applied to the liquid crystal layer 30 to change from a state greater than the off threshold Voff to a state equal to or less than the off threshold Voff. As a result, it is possible to prevent the timing of the change in the polarization direction of light by the liquid crystal shutter device 301 from being delayed with respect to the display timing of the display panel 2. The other configurations and effects are similar to those of the first embodiment.

[0038] [Variations] Although the embodiment of the invention has been described above, the above-mentioned embodiment is merely an example for carrying out the invention. Therefore, the present invention is not limited to the above-mentioned embodiment, and can be appropriately modified and carried out without departing from the spirit of the invention. Below, a modified example of the above-mentioned embodiment will be described.

[0039] (1) In the above first and second embodiments, the counter electrode of the present disclosure is configured as a plurality of parts (a plurality of counter electrodes) spaced apart from each other, but the present disclosure is not limited to this. For example, as in a liquid crystal shutter device 401 according to a first modified example shown in FIG. 15, a single counter electrode 421 may be provided in a liquid crystal shutter device 401.

[0040] (2) In the above first and second embodiments, the auxiliary electrode of the present disclosure is configured as a plurality of parts (a plurality of auxiliary electrodes) spaced apart from each other, but the present disclosure is not limited to this. For example, as in a liquid crystal shutter device 501 according to a second modified example shown in FIG. 16, a single auxiliary electrode 523 may be provided in a liquid crystal shutter device 501.

[0041] (3) In the above first and second embodiments, the auxiliary electrode has a structure in which a plurality of linear conductors aligned along the pixel arrangement direction (the vertical and horizontal directions in FIG. 6) intersect, but the present disclosure is not limited to this. For example, like an auxiliary electrode 623 according to a third modification shown in FIG. 17, an auxiliary electrode 523 may have a structure in which a plurality of linear conductors intersect in a direction intersecting the pixel arrangement direction (the diagonal direction in the paper).

[0042] (4) In the above first and second embodiments, the counter electrode is connected to the ground (GND), but the present disclosure is not limited to this. That is, the counter electrode may not be connected to the ground (GND), and a predetermined voltage having a potential (fixed potential) other than the ground (GND) may be applied from the drive circuit.

[0043] (5) In the above first and second embodiments, an example was shown in which a ground voltage was applied to the segment electrodes, but the present disclosure is not limited to this. In other words, if the polarization direction of the light emitted from the liquid crystal shutter device can be switched, a voltage value different from the ground potential may be applied to the segment electrodes during the period in which the above-mentioned ground voltage is applied.

[0044] (6) In the first embodiment, the auxiliary electrodes are disposed within the region Ra, and in the second embodiment, the auxiliary electrodes are disposed outside the region Ra (within the region Rb), but the present disclosure is not limited to this. For example, the auxiliary electrodes may be disposed both within the region Ra and within the region Rb.

[0045] (7) In the second embodiment, the auxiliary electrode is U-shaped in a plan view, but the present disclosure is not limited to this. For example, the auxiliary electrode may be I-shaped, circular, or rectangular.

[0046] (8) In the above first and second embodiments, the polarization direction of linearly polarized light is switched as an example of the polarization state of the emitted light that is switched by the liquid crystal shutter device, but the present disclosure is not limited to this. For example, the rotation direction of circularly polarized light may be switched by the liquid crystal shutter device. In this case, an optical element that blocks one of left-handed circularly polarized light and right-handed circularly polarized light is arranged in the left-eye rim of the polarized glasses, and an optical element that blocks the other is arranged in the right-eye rim of the polarized glasses, so that the user can view a stereoscopic image.

[0047] The above-described stereoscopic display system and liquid crystal shutter device can also be explained as follows.

[0048] A stereoscopic display system according to a first configuration includes a display panel that alternately displays an image for a left eye and an image for a right eye, and a liquid crystal shutter device that switches between a state in which light incident from the display panel is changed to output light having a first polarization state and a state in which light incident from the display panel is changed to output light having a second polarization state and output, the liquid crystal shutter device including a first electrode, a second electrode connected to a fixed potential, a liquid crystal layer disposed between the first electrode and the second electrode, and a liquid crystal layer that changes the polarization state of the output light to the first polarization state. a drive circuit that applies to the first electrode either a first voltage that changes the polarization state of the emitted light to the second polarization state, and a second voltage that changes the polarization state of the emitted light to the second polarization state, the drive circuit switching the voltage to be applied to the first electrode between the first voltage and the second voltage in synchronization with switching of the display of the left eye image and the right eye image by the display panel, and a third electrode that is arranged on the opposite side of the second electrode to the side on which the liquid crystal layer is arranged, and the drive circuit applies to the third electrode a third voltage having an opposite phase to the voltage applied to the first electrode (first configuration).

[0049] Here, the potential of the second electrode changes with respect to a fixed potential due to the application of the first voltage to the first electrode. In contrast, according to the first configuration, the third voltage having a phase opposite to that of the voltage applied to the first electrode is applied to the third electrode. This allows the potential of the second electrode to be changed in a phase opposite to that of the change in potential due to the first voltage. As a result, the change in potential due to the third voltage cancels out the change in potential due to the first voltage, so that it is possible to prevent an increase in the time constant of the waveform of the voltage applied to the liquid crystal layer (dulling of the waveform). This prevents a delay in the timing at which the polarization state of the light emitted from the liquid crystal shutter device is switched relative to the timing at which the voltage applied to the first electrode is switched between the first voltage and the second voltage. And, since the timing at which the voltage applied to the first electrode is switched between the first voltage and the second voltage is synchronized with the timing at which the image for the left eye and the image for the right eye are switched (display timing), it is possible to prevent a delay in the timing at which the polarization state of the light is changed by the liquid crystal shutter device relative to the display timing of the display panel.

[0050] In the first configuration, the driving circuit may be configured to apply the third voltage, having an absolute value of a voltage value less than or equal to either the absolute value of the voltage value of the first voltage or the absolute value of the voltage value of the second voltage, to the third electrode (second configuration).

[0051] According to the second configuration, it is possible to prevent the change in the potential of the second electrode caused by the third voltage from exceeding a magnitude that offsets the change in the potential of the second electrode caused by the first voltage.

[0052] In the first or second configuration, when the absolute value of the voltage value of the first voltage or the absolute value of the voltage value of the second voltage is Vs, the capacitance between the first electrode and the second electrode is CL, and the capacitance between the second electrode and the third electrode is Cs, the drive circuit applies the third voltage having an absolute value Vc that satisfies the following formula (1a) to the third electrode (third configuration). Vc≦Vs × (CL / Cs) (1a)

[0053] According to the third configuration, it is possible to minimize the time constant of the waveform of the voltage applied to the liquid crystal layer while preventing the change in the potential of the second electrode caused by the third voltage from exceeding a magnitude that offsets the change in the potential of the second electrode caused by the first voltage.

[0054] In any one of the first to third configurations, the third electrode may be formed in a mesh shape (fourth configuration).

[0055] According to the fourth configuration, the gaps in the mesh of the third electrode do not block light, so that the light transmittance of the liquid crystal shutter device can be improved.

[0056] In any one of the first to fourth configurations, the third electrode may be disposed at a position of the liquid crystal shutter device outside an area from which the liquid crystal shutter device emits light (fifth configuration).

[0057] According to the fifth configuration, the third electrode is disposed at a position outside the area that affects the display, so that the third electrode can be prevented from affecting the display.

[0058] In any one of the first to fifth configurations, the first electrode may include a plurality of first electrode portions arranged apart from one another. The second electrode may include a plurality of second electrode portions arranged opposite the plurality of first electrode portions. The third electrode may include a plurality of third electrode portions arranged opposite the plurality of second electrode portions (sixth configuration).

[0059] According to the sixth configuration, it is possible to reduce the electric capacitance between the first electrode and the second electrode, and the electric capacitance between the second electrode and the third electrode, thereby making it possible to reduce the time constant of the waveform of the voltage applied to the liquid crystal layer.

[0060] A liquid crystal shutter device according to a seventh configuration is a liquid crystal shutter device that switches between a state in which light incident from a display panel that alternately displays left-eye images and right-eye images is changed into output light having a first polarization state and a state in which light incident from the display panel is changed into output light having a second polarization state and output, and includes a first electrode, a second electrode connected to a fixed potential, a liquid crystal layer disposed between the first electrode and the second electrode, a first voltage that changes the polarization state of the output light to the first polarization state, and a second voltage that changes the polarization state of the emitted light to the second polarization state, the drive circuit switching the voltage to be applied to the first electrode between the first voltage and the second voltage in synchronization with switching of the display of the left eye image and the right eye image by the display panel, and a third electrode arranged on the opposite side of the second electrode to the side on which the liquid crystal layer is arranged, and the drive circuit applies a third voltage having an opposite phase to the voltage applied to the first electrode to the third electrode (seventh configuration).

[0061] According to the seventh configuration, it is possible to provide a liquid crystal shutter device that can prevent a delay in the timing of changing the polarization state of light by the liquid crystal shutter device relative to the display timing of the display panel. [Explanation of symbols]

[0062] 1,301,401,501... liquid crystal shutter device, 2... display panel, 3... liquid crystal shutter device drive circuit, 4... display panel drive circuit, 11... segment electrode, 21,421... counter electrode, 23,323,523,623... auxiliary electrode, 24,324... insulating layer, 30... liquid crystal layer, 100... stereoscopic display system

Claims

1. a display panel that alternately displays an image for the left eye and an image for the right eye; a liquid crystal shutter device that switches between a state in which light incident from the display panel is changed to output light having a first polarization state and a state in which light incident from the display panel is changed to output light having a second polarization state, The liquid crystal shutter device is A first electrode; A second electrode connected to a fixed potential; a liquid crystal layer disposed between the first electrode and the second electrode; a drive circuit that applies to the first electrode either a first voltage that changes the polarization state of the emitted light to the first polarization state or a second voltage that changes the polarization state of the emitted light to the second polarization state, and that switches the voltage applied to the first electrode between the first voltage and the second voltage in synchronization with switching of display of the left eye image and the right eye image by the display panel; a third electrode disposed on a side of the second electrode opposite to a side on which the liquid crystal layer is disposed, The driving circuit applies a third voltage to the third electrode, the third voltage having an opposite phase to the voltage applied to the first electrode.

2. 2. The stereoscopic display system according to claim 1, wherein the driving circuit applies the third voltage, which has an absolute value that is less than or equal to either one of the absolute value of the voltage value of the first voltage or the absolute value of the voltage value of the second voltage, to the third electrode.

3. 2. The stereoscopic display system according to claim 1, wherein the drive circuit applies to the third electrode the third voltage having an absolute voltage value Vc that satisfies the following formula (1), where Vs is an absolute value of the voltage value of the first voltage or the absolute value of the voltage value of the second voltage, CL is an electric capacitance between the first electrode and the second electrode, and Cs is an electric capacitance between the second electrode and the third electrode. Vc≦Vs×(CL / Cs)...(1)

4. 4. The stereoscopic display system according to claim 1, wherein the third electrode is formed in a mesh shape.

5. 4. The stereoscopic display system according to claim 1, wherein the third electrode is disposed at a position of the liquid crystal shutter device outside an area from which the liquid crystal shutter device emits light.

6. the first electrode includes a plurality of first electrode portions spaced apart from one another; the second electrode includes a plurality of second electrode portions disposed opposite the plurality of first electrode portions; 4. The stereoscopic display system according to claim 1, wherein the third electrode includes a plurality of third electrode portions arranged opposite the plurality of second electrode portions.

7. A liquid crystal shutter device that switches between a state in which light incident from a display panel that alternately displays a left eye image and a right eye image is changed into output light having a first polarization state and a state in which light incident from the display panel is changed into output light having a second polarization state and the output light is A first electrode; A second electrode connected to a fixed potential; a liquid crystal layer disposed between the first electrode and the second electrode; a drive circuit that applies to the first electrode either a first voltage that changes the polarization state of the emitted light to the first polarization state or a second voltage that changes the polarization state of the emitted light to the second polarization state, and that switches the voltage applied to the first electrode between the first voltage and the second voltage in synchronization with switching of display of the left eye image and the right eye image by the display panel; a third electrode disposed on a side of the second electrode opposite to a side on which the liquid crystal layer is disposed, The drive circuit applies a third voltage to the third electrode, the third voltage having an opposite phase to the voltage applied to the first electrode.

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