Liquid crystal light deflector and driving method of liquid crystal light deflector

Abstract

To provide a liquid crystal light deflector and a driving method of the liquid crystal light deflector that can suppress unevenness in optical characteristics occurring during the transition from a state causing deflection to a state causing no deflection, and can shorten the response time for transition from the state causing deflection to the state causing no deflection.SOLUTION: A liquid crystal light deflector includes a liquid-crystal light deflection panel 10 and a controller. The liquid-crystal light deflection panel 10 includes liquid crystals 60 and electrodes 40, 50 to apply an electric field to the liquid crystals 60. The controller applies, to the liquid crystals 60, a predetermined electric field for driving the liquid crystals 60 in a direction orthogonal to an initial alignment direction of the liquid crystals 60, and thus causes the liquid-crystal light deflection panel 10 to transition to a first state causing deflection. The controller applies, to the liquid crystals 60, a uniform electric field for driving at least some of the liquid crystals 60 in the direction orthogonal to the initial alignment direction, and thus causes the liquid-crystal light deflection panel 10 to transition from the first state to a second state causing no deflection.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a liquid crystal optical deflection device and a method for driving a liquid crystal optical deflection device. [Background technology]

[0002] Liquid crystal light deflection elements are known that deflect light by changing the orientation of liquid crystals, and act as a lens, prism, etc. For example, Patent Document 1 discloses a liquid crystal lens that includes two electrode structures (a first electrode structure and a second electrode structure) spaced apart from each other and a liquid crystal layer disposed between the two electrode structures.

[0003] In Patent Document 1, the first electrode structure includes a plurality of first linear electrodes extending along a first extension direction, and the second electrode structure includes a plurality of second linear electrodes extending along a second extension direction intersecting the first extension direction, and a planar electrode. A first electric field is generated by forming a voltage difference between the first linear electrodes, the second linear electrodes, and the planar electrode. The first electric field changes the alignment direction of the liquid crystal layer, thereby providing a lens effect to the liquid crystal layer. A second electric field is generated by forming a voltage difference between the planar electrode and the second linear electrode. The second electric field returns the liquid crystal layer to its initial alignment direction, eliminating the lens effect from the liquid crystal layer.

[0004] In Patent Document 1, a second electric field is applied to the liquid crystal layer to return the liquid crystal layer to its initial alignment direction, thereby shortening the time it takes for the liquid crystal molecules in the liquid crystal layer to return to the non-lens effect state (initial alignment state). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5536004 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, three electrodes are required to generate the first and second electric fields: a first linear electrode, a second linear electrode, and a plane electrode, which makes the electrode configuration of the liquid crystal lens complex, and also makes the drive circuit for driving the liquid crystal lens complex.

[0007] In Patent Document 1, the second electric field generated between the plane electrode and the second linear electrode and used to return the liquid crystal layer to its initial alignment direction is a horizontal electric field. However, when the second electric field (horizontal electric field) is generated between the plane electrode and the second linear electrode, a vertical electric field (electric field in the thickness direction of the liquid crystal layer) is also generated between the second linear electrode and the first linear electrode facing the second linear electrode. Therefore, when the liquid crystal layer is returned to its initial alignment direction, the alignment of the liquid crystal layer is disturbed by the vertical electric field. As a result, in the liquid crystal lens of Patent Document 1, when the liquid crystal lens (liquid crystal molecules) returns to its non-lensing state, the refractive index distribution of the liquid crystal layer is disturbed, causing uneven optical characteristics in the liquid crystal lens.

[0008] The present disclosure has been made in consideration of the above circumstances, and aims to provide a liquid crystal optical deflection device and a method for driving a liquid crystal optical deflection device that can suppress unevenness in optical characteristics that occurs when changing the state from one in which a deflection effect is produced to one in which no deflection effect is produced, and can shorten the response time from one in which a deflection effect is produced to one in which no deflection effect is produced. [Means for solving the problem]

[0009] A liquid crystal optical deflection device according to a first aspect of the present invention comprises: a liquid crystal optical deflection panel including a first substrate onto which light is incident, a second substrate facing the first substrate, a liquid crystal sandwiched between the first substrate and the second substrate, and a plurality of electrodes that apply an electric field to the liquid crystal; a control unit that controls the deflection action of the liquid crystal light deflection panel on the light, The control unit a predetermined electric field is applied to the liquid crystal to drive the liquid crystal in a direction perpendicular to an initial alignment direction of the liquid crystal, and to the liquid crystal to generate a refractive index distribution corresponding to the deflection effect, thereby bringing the liquid crystal optical deflection panel into a first state in which the deflection effect is exerted; By applying a uniform electric field to the liquid crystal that drives at least a portion of the liquid crystal in the direction perpendicular to the initial alignment direction, the state of the liquid crystal optical deflection panel is switched from the first state to a second state in which the deflection effect is not exerted.

[0010] A method for driving a liquid crystal optical deflection device according to a second aspect includes: a step of applying a predetermined electric field to the liquid crystal of the liquid crystal optical deflection panel, which drives the liquid crystal in a direction perpendicular to the initial alignment direction of the liquid crystal, and generates a refractive index distribution in the liquid crystal according to the deflection effect, thereby bringing the state of the liquid crystal optical deflection panel into a first state in which the deflection effect is exhibited; and applying a uniform electric field to the liquid crystal that drives at least a portion of the liquid crystal in the direction perpendicular to the initial alignment direction, thereby switching the state of the liquid crystal optical deflection panel from the first state to a second state in which the deflection effect is not exerted. [Effects of the Invention]

[0011] By applying an electric field that drives at least a portion of the liquid crystal in a direction perpendicular to the initial alignment direction, the state of the liquid crystal optical deflection panel is switched from a first state in which a deflection effect is exerted to a second state in which a deflection effect is not exerted, thereby suppressing unevenness in the optical characteristics that occurs when the state is changed from a state in which a deflection effect is exerted to a state in which a deflection effect is not exerted, and shortening the response time from a state in which a deflection effect is exerted to a state in which a deflection effect is not exerted. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing a liquid crystal optical deflection device, a liquid crystal display panel, and a display device according to a first embodiment. [Figure 2] 2 is a cross-sectional view of the liquid crystal optical deflection panel shown in FIG. 1 taken along line AA. [Figure 3] FIG. 2 is a plan view showing a first electrode according to the first embodiment. [Figure 4] FIG. 3 is a plan view showing a second electrode according to the first embodiment. [Figure 5]FIG. 2 is a diagram illustrating a hardware configuration of a control unit according to the first embodiment. [Figure 6] FIG. 2 is a schematic diagram showing the alignment state of liquid crystal in the initial state according to the first embodiment. [Figure 7] 4 is a diagram showing a refractive index distribution for linearly polarized light in an initial state according to the first embodiment. FIG. [Figure 8] 3 is a schematic diagram showing the alignment state of liquid crystal in a first state according to the first embodiment. FIG. [Figure 9] FIG. 4 is a diagram showing the potential of a first electrode according to the first embodiment. [Figure 10] 4 is a diagram showing a refractive index distribution for linearly polarized light in a first state according to the first embodiment. FIG. [Figure 11] 4 is a schematic diagram showing the alignment state of liquid crystal in a second state according to the first embodiment. FIG. [Figure 12] 6 is a diagram showing a refractive index distribution for linearly polarized light in a second state according to the first embodiment. FIG. [Figure 13] 3A to 3C are schematic diagrams illustrating the disturbance of the alignment of liquid crystal molecules according to the first embodiment. [Figure 14] 5 is a diagram showing the potential of the first electrode when a predetermined electric field is applied to the liquid crystal according to the first embodiment. FIG. [Figure 15] 4 is a diagram showing a change in refractive index distribution for linearly polarized light according to the first embodiment. FIG. [Figure 16] 10 is a diagram showing a change in refractive index distribution for linearly polarized light according to Comparative Example 1. FIG. [Figure 17] FIG. 4 is a diagram showing the relationship between the voltage applied to the liquid crystal and the response time according to the first embodiment. [Figure 18] 4 is a diagram showing a change in refractive index distribution for linearly polarized light according to the first embodiment. FIG. [Figure 19] 5 is a flowchart showing a driving process of the liquid crystal optical deflection device according to the first embodiment. [Figure 20] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in the initial state according to the second embodiment. [Figure 21] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in an initial state according to the second embodiment. [Figure 22] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in a first state according to the second embodiment. [Figure 23] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in a first state according to the second embodiment. [Figure 24] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in a second state according to the second embodiment. [Figure 25] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in a second state according to the second embodiment. [Figure 26] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in the initial state according to the third embodiment. [Figure 27] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in an initial state according to the third embodiment. [Figure 28] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in a first state according to a third embodiment. [Figure 29] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in a first state according to the third embodiment. [Figure 30] FIG. 10 is a plan view showing a second electrode according to a fourth embodiment. [Figure 31] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in an initial state according to the fourth embodiment. [Figure 32] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in a first state according to a fourth embodiment. [Figure 33] FIG. 10 is a diagram showing the potential of a second electrode according to the fourth embodiment. [Figure 34] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in a first state according to the fourth embodiment. [Figure 35] FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in a second state according to the fourth embodiment. [Figure 36] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in a first state according to a fifth embodiment. [Figure 37] FIG. 10 is a diagram showing the potential of the first electrode according to the fifth embodiment. [Figure 38]FIG. 10 is a diagram showing a refractive index distribution for linearly polarized light in a first state according to the fifth embodiment. [Figure 39] FIG. 10 is a cross-sectional view of a liquid crystal optical deflection panel according to a sixth embodiment. [Figure 40] FIG. 10 is a plan view showing an electrode according to a sixth embodiment. [Figure 41] FIG. 13 is a schematic diagram showing the alignment state of liquid crystal in a first state according to a sixth embodiment. [Figure 42] FIG. 13 is a schematic diagram showing the alignment state of liquid crystal in a second state according to the sixth embodiment. [Figure 43] 13 is a flowchart showing a driving process of a liquid crystal optical deflection device according to a seventh embodiment. [Figure 44] FIG. 13 is a diagram showing the potential of the first electrode according to the eighth embodiment. [Figure 45] FIG. 13 is a diagram showing the potential of the first electrode when a first electric field is applied to the liquid crystal according to the eighth embodiment. [Figure 46] FIG. 13 is a diagram showing a change in refractive index distribution for linearly polarized light according to the eighth embodiment. [Figure 47] 10 is a diagram showing a change in refractive index distribution for linearly polarized light according to Comparative Example 2. FIG. [Figure 48] FIG. 13 is a schematic diagram showing the alignment state of liquid crystal in a second state according to the eighth embodiment. [Figure 49] FIG. 13 is a diagram showing a change in refractive index distribution for linearly polarized light according to the eighth embodiment. [Figure 50] FIG. 10 is a diagram showing a change in refractive index distribution for linearly polarized light according to Comparative Example 3. [Figure 51] 13 is a flowchart showing a driving process of a liquid crystal optical deflection device according to an eighth embodiment. [Figure 52] FIG. 20 is a diagram showing the relationship between elapsed time and the potential of the first electrode, and the magnitude relationship of the potential at each of the first electrodes at each elapsed time, according to the ninth embodiment. [Figure 53] 13 is a flowchart showing a driving process of a liquid crystal optical deflection device according to a ninth embodiment. [Figure 54] FIG. 10 is a plan view showing a first electrode according to a modified example. [Figure 55] FIG. 10 is a plan view showing a first electrode according to a modified example. [Figure 56] FIG. 10 is a schematic diagram showing the alignment state of liquid crystal in a second state according to a modified example. [Figure 57] FIG. 10 is a diagram showing the relationship between elapsed time and the period during which a voltage is applied to the first electrode, according to a modified example. [Figure 58] FIG. 10 is a diagram showing the relationship between elapsed time, the potential of the first electrode, and the period during which the first electrode is applied, according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a liquid crystal optical deflection device according to an embodiment will be described with reference to the drawings.

[0014] <Embodiment 1> A liquid crystal light deflection device 100 according to this embodiment will be described with reference to FIGS. 1 to 17. As shown in FIG. 1, the liquid crystal light deflection device 100 includes a liquid crystal light deflection panel 10 and a control unit 90. The liquid crystal light deflection panel 10 deflects light by changing the orientation of liquid crystals 60, which will be described later. The liquid crystal light deflection panel 10 functions as, for example, a lenticular lens. The control unit 90 controls the deflection action of the liquid crystal light deflection panel 10.

[0015] For example, the liquid crystal optical deflection panel 10 is disposed on the display surface side of the liquid crystal display panel 200. The liquid crystal optical deflection device 100, together with the liquid crystal display panel 200, constitutes a display device 300 that displays two-dimensional images and three-dimensional images. For ease of understanding, in this specification, the right direction of the liquid crystal optical deflection panel 10 in Fig. 1 (the right direction on the paper) is defined as the +X direction, the upward direction (the upward direction on the paper) is defined as the +Y direction, and the direction perpendicular to the +X and +Y directions (toward the viewer on the paper) is defined as the +Z direction.

[0016] The liquid crystal light deflection panel 10 can be in an initial state, a first state, or a second state. The initial state refers to a state in which the liquid crystal 60 is in an initial alignment state, has a uniform refractive index distribution, and does not deflect light (linearly polarized light). The first state refers to a state in which the liquid crystal 60 is aligned in a predetermined manner by a predetermined electric field (voltage) that drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction, the refractive index distribution changes at a predetermined period, and the liquid crystal 60 deflects light. The second state refers to a state in which the liquid crystal 60 is aligned uniformly, has a uniform refractive index distribution, and does not deflect light by applying a uniform electric field (voltage) to the liquid crystal 60 and driving at least a portion of the liquid crystal 60 in a direction perpendicular to the initial alignment direction (the same direction as when the first state is formed from the initial state). In the first state of this embodiment, the refractive index distribution of the liquid crystal optical deflection panel 10 changes at a predetermined cycle along the X direction, and the liquid crystal optical deflection panel 10 functions as a lenticular lens array in which cylindrical lenses extending in the Y direction are arranged in the X direction. Note that the initial alignment direction of the liquid crystal refers to the alignment direction of the liquid crystal 60 (liquid crystal molecules) when the liquid crystal 60 in the initial alignment state (state in which no electric field is applied) is viewed in a planar or cross-sectional view.

[0017] When the liquid crystal optical deflection panel 10 is in the initial state or the second state, the liquid crystal optical deflection panel 10 does not function as a lenticular lens array, and the display device 300 displays a two-dimensional image. When the liquid crystal optical deflection panel 10 is in the first state, the liquid crystal optical deflection panel 10 functions as a lenticular lens array, and the display device 300 displays a three-dimensional image.

[0018] A specific configuration of the liquid crystal optical deflection panel 10 will be described. As shown in Fig. 2, the liquid crystal optical deflection panel 10 includes a first substrate 20, a second substrate 30, a plurality of first electrodes 40, a second electrode 50, and a liquid crystal 60. The first substrate 20 and the second substrate 30 sandwich the liquid crystal 60. The plurality of first electrodes 40 and the second electrode 50 face each other, and apply an electric field (voltage) to the liquid crystal 60.

[0019] The first substrate 20 of the liquid crystal optical deflection panel 10 transmits visible light. The first substrate 20 is, for example, a flat glass substrate. A plurality of first electrodes 40 are arranged on a first main surface 20a of the first substrate 20 facing the liquid crystal 60. An alignment film 22 is also provided on the first substrate 20. The alignment film 22 covers the first main surface 20a of the first substrate 20 and the plurality of first electrodes 40, and aligns the liquid crystal 60 in a predetermined direction. The alignment film 22 is, for example, a polyimide alignment film that has been subjected to an alignment treatment.

[0020] Linearly polarized light L1 is incident from the -Z side onto the second major surface 20b opposite to the first major surface 20a of the first substrate 20. In this embodiment, the polarization direction of the linearly polarized light L1 is the Y direction.

[0021] The second substrate 30 of the liquid crystal optical deflection panel 10 transmits visible light. The second substrate 30 is, for example, a flat glass substrate. The second substrate 30 faces the first substrate 20 and is attached to the first substrate 20 with a sealant 70. A second electrode 50 is disposed on a first main surface 30a of the second substrate 30 on the liquid crystal 60 side. An alignment film 32 is also provided on the second substrate 30. The alignment film 32 covers the second electrode 50 and aligns the liquid crystal 60 in a predetermined direction. The alignment film 32 is also a polyimide alignment film that has been subjected to an alignment treatment.

[0022] As shown in FIGS. 2 and 3, the first electrodes 40 of the liquid crystal optical deflection panel 10 are provided on the first main surface 20a of the first substrate 20. The first electrodes 40 are linear electrodes having a rectangular shape, extending along the Y direction, and arranged at predetermined intervals in the X direction. Each of the first electrodes 40 is connected to the control unit 90 via wiring (not shown). The first electrodes 40 are formed of a conductive film that transmits visible light. The first electrodes 40 are formed of, for example, ITO (Indium Tin Oxide). In this embodiment, the Y direction corresponds to the predetermined first direction.

[0023] As shown in FIGS. 2 and 4, the second electrode 50 of the liquid crystal optical deflection panel 10 is provided on the first main surface 30a of the second substrate 30. The second electrode 50 is formed in a rectangular shape and faces the plurality of first electrodes 40. The second electrode 50 is connected to the control unit 90 via wiring (not shown). The second electrode 50 is formed of a conductive film that transmits visible light. The second electrode 50 is formed from, for example, ITO.

[0024] The liquid crystal 60 of the liquid crystal optical deflection panel 10 is sandwiched between the first substrate 20 and the second substrate 30. The liquid crystal 60 is, for example, a positive nematic liquid crystal. The liquid crystal 60 in an initial alignment state is aligned in the Y direction by the alignment film 22 and the alignment film 32.

[0025] The control unit 90 switches the state of the liquid crystal optical deflection panel 10 by controlling the electric field (voltage) applied to the liquid crystal 60 via the multiple first electrodes 40 and second electrodes 50. In this embodiment, the control unit 90 switches the state of the liquid crystal optical deflection panel 10 from an initial state in which the liquid crystal 60 is in an initial alignment state, has a uniform refractive index distribution, and does not deflect linearly polarized light L1, to a first state in which the liquid crystal 60 is driven by a predetermined electric field in a direction perpendicular to the initial alignment direction, aligns in a predetermined manner, changes its refractive index distribution at a predetermined period, and deflects light. The predetermined electric field (voltage) drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60, causing the liquid crystal 60 to produce a refractive index distribution in the liquid crystal 60 corresponding to the deflection effect.

[0026] The control unit 90 also switches the state of the liquid crystal optical deflection panel 10 from the first state to a second state in which at least a portion of the liquid crystal 60 is driven by a uniform electric field in a direction perpendicular to the initial alignment direction, resulting in a uniform alignment of the liquid crystal 60, a uniform refractive index distribution, and no deflection of light. The direction perpendicular to the initial alignment direction along which the liquid crystal 60 is driven when switching from the initial state to the first state is the same as the direction perpendicular to the initial alignment direction along which at least a portion of the liquid crystal 60 is driven when switching from the first state to the second state. The control unit 90 also switches the state of the liquid crystal optical deflection panel 10 from the second state to the initial state. Details of the control by the control unit 90 and the operation of the liquid crystal optical deflection panel 10 will be described later.

[0027] FIG. 5 shows the hardware configuration of the control unit 90. The control unit 90 includes, for example, a CPU (Central Processing Unit) 92, a ROM (Read Only Memory) 93, a RAM (Random Access Memory) 94, a power supply circuit 96, and an input / output interface 98. The CPU 92 executes programs stored in the ROM 93. The ROM 93 stores programs, data, etc. The RAM 94 stores data. The power supply circuit 96 is connected to the first electrode 40 and the second electrode 50, and applies an electric field to the liquid crystal 60 via the first electrode 40 and the second electrode 50. The input / output interface 98 inputs and outputs signals to and from external devices. The functions of the control unit 90 are realized by the CPU 92 executing the programs stored in the ROM 93.

[0028] The following describes the control of the control unit 90 and the operation of the liquid crystal optical deflection panel 10. The liquid crystal optical deflection panel 10 functions as a lenticular lens array by changing the orientation of the liquid crystals 60.

[0029] First, the initial state of the liquid crystal optical deflection panel 10 will be described. In the initial state of the liquid crystal optical deflection panel 10, the control unit 90 applies no electric field to the liquid crystal 60 by setting the potential of the first electrode 40 and the potential of the second electrode 50 to the same potential (e.g., ground potential), thereby maintaining the liquid crystal 60 in the initial orientation state (alignment in the Y direction) shown in FIG. 6. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction becomes uniform as shown in FIG. 7 (a state in which the refractive index for linearly polarized light L1 is constant at the extraordinary refractive index n e of the liquid crystal 60), and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array. Note that n e in FIG. 7 indicates the ordinary refractive index of the liquid crystal 60.

[0030] When the liquid crystal light deflection panel 10 is made to function as a lenticular lens array, the control unit 90 controls the potentials (voltages) of the plurality of first electrodes 40 and the potentials (voltages) of the second electrodes 50, and applies a predetermined electric field to the liquid crystal 60 to drive the liquid crystal 60 in a direction perpendicular to the initial alignment direction, thereby driving the liquid crystal 60 in a direction perpendicular to the initial alignment direction and aligning the liquid crystal 60 in a predetermined manner, thereby switching to a first state in which the liquid crystal 60 exhibits a deflecting effect on linearly polarized light L1. The predetermined electric field is an electric field that drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60 and generates a refractive index distribution in the liquid crystal 60 according to the deflecting effect.

[0031] Specifically, the control unit 90 sets the potential of the second electrode 50 to ground potential, and sets the potentials of the first electrodes 40a and 40e shown in FIG. 8 to potentials ±Va1 and ±Ve1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action (FIG. 9). The control unit 90 also sets the potentials of the first electrodes 40b and 40d to potentials ±Vb1 and ±Vd1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action, and sets the potential of the first electrode 40c to potential ±Vc1 that causes the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action (FIG. 9). The magnitudes of the potentials ±Va1 to ±Ve1 are in the following order: absolute value of ±Va1 = absolute value of ±Ve1 > absolute value of ±Vb1 = absolute value of ±Vd1 > absolute value of ±Vc1. As a result, a predetermined electric field is applied to the liquid crystal 60, and the liquid crystal 60 is driven in the +Z direction. As shown in FIG. 8, the liquid crystal molecules rise more in the +Z direction relative to the first major surface 20a of the first substrate 20 from the first electrode 40c toward the first electrode 40a, and also rise more in the +Z direction relative to the first major surface 20a of the first substrate 20 from the first electrode 40c toward the first electrode 40e. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction is such that a quadratic curve-like refractive index change is repeated at a predetermined period along the X direction, as shown in FIG. 10, and the liquid crystal optical deflection panel 10 functions as a lenticular lens array extending in the Y direction and arranged in the X direction. Note that FIG. 8 omits liquid crystal molecules near the interface between the alignment films 22 and 32, which are less responsive to an electric field. Liquid crystal molecules near the interface between the alignment films 22 and 32 are also omitted in the following figures.

[0032] When switching the state of the liquid crystal optical deflection panel 10 from a state in which it functions as a lenticular lens array to a state in which it does not function as a lenticular lens array, the control unit 90 applies a uniform electric field (voltage) to the liquid crystal 60 to drive the liquid crystal 60 in a direction similar to the direction in which the liquid crystal 60 is driven, in order to form the first state from the initial state, by controlling the potentials (voltages) of the plurality of first electrodes 40 and the potentials (voltages) of the second electrodes 50. As a result, at least a portion of the liquid crystal 60 is driven in the same direction (direction perpendicular to the initial alignment direction) as when the first state is formed from the initial alignment state, and the liquid crystal optical deflection panel 10 is switched to the second state in which it does not deflect the linearly polarized light L1.

[0033] Specifically, in order to apply a uniform electric field to the liquid crystal 60, the control unit 90 sets the potential of the second electrode to ground potential and the potential of the first electrodes 40a-40e to the same predetermined potential (for example, a potential that aligns the liquid crystal 60 in the Z direction). As a result, at least a portion of the liquid crystal 60 (the liquid crystal 60 located in the region between the first electrode 40a and the first electrode 40e in a plan view) is driven toward the +Z direction, and the liquid crystal molecules are oriented, for example, in the Z direction, resulting in a uniform alignment of the liquid crystal 60 (FIG. 11). In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 becomes uniform (a state in which the refractive index for linearly polarized light L1 is constant at the ordinary refractive index n of the liquid crystal 60), as shown in FIG. 12, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0034] In this embodiment, the control unit 90 switches the state of the liquid crystal optical deflection panel 10 from a first state in which the liquid crystal 60 is oriented in a predetermined manner and exhibits a deflecting effect to a second state in which the deflecting effect is not exhibited by applying a uniform electric field to the liquid crystal 60 and driving the liquid crystal 60 in a direction perpendicular to the initial alignment direction (the same direction as when forming the first state from the initial state), thereby switching the state of the liquid crystal optical deflection panel 10 from a first state in which the liquid crystal 60 is oriented in a predetermined manner and exhibits a deflecting effect to a second state in which the deflecting effect is not exhibited. Therefore, compared to when the state of the liquid crystal optical deflection panel 10 is returned from the first state in which the deflecting effect is exhibited to the initial state in which the deflecting effect is not exhibited by not applying an electric field, the liquid crystal optical deflection device 100 can shorten the response time from a state in which the deflecting effect is exhibited to a state in which the deflecting effect is not exhibited.

[0035] Furthermore, the control unit 90 applies a uniform electric field to the liquid crystal 60 and drives the liquid crystal 60 in a direction perpendicular to the initial orientation direction, thereby uniformly aligning the liquid crystal 60. This makes it possible to suppress disturbances in the orientation of the liquid crystal 60 when the state of the liquid crystal optical deflection panel 10 changes from a state in which it exerts a deflection effect to a state in which it does not exert a deflection effect, thereby suppressing unevenness in the optical characteristics of the liquid crystal optical deflection panel 10.

[0036] For example, in a configuration including first linear electrodes, second linear electrodes, and plane electrodes, such as the liquid crystal lens described in Japanese Patent No. 5536004, when the liquid crystal layer is returned to its initial alignment direction, a vertical electric field is generated in addition to a horizontal electric field, resulting in a disturbance in the alignment of the liquid crystal layer (liquid crystal molecules) as shown in FIG. 13. This disturbance in the alignment of the liquid crystal layer occurs because the liquid crystal molecules in the area where the horizontal electric field is strong (between the second linear electrodes) and the liquid crystal molecules in the area where the vertical electric field is strong (above the second linear electrodes) rise to different degrees in the +Z direction. As a result, the liquid crystal lens exhibits uneven optical characteristics. The liquid crystal optical deflection device 100 can suppress such uneven optical characteristics caused by the disturbance in the alignment of the liquid crystal layer (the alignment of the liquid crystal 60).

[0037] Furthermore, in this embodiment, the electrodes (first electrode 40 and second electrode 50) that apply an electric field to the liquid crystal 60 to cause the liquid crystal optical deflection panel 10 to have a deflection effect are the same as the electrodes (first electrode 40 and second electrode 50) that apply an electric field to the liquid crystal 60 to cause the liquid crystal optical deflection panel 10 to have no deflection effect. Therefore, the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90 can be simplified.

[0038] In this embodiment, the control unit 90 may switch the state of the liquid crystal optical deflection panel 10 from the second state in which no deflection action is exerted to the initial state in which no deflection action is exerted by controlling the potential of the first electrode 40 and the potential of the second electrode 50 and stopping the application of the uniform electric field to the liquid crystal 60. Since the liquid crystal 60 is uniformly oriented in the second state, when the state of the liquid crystal optical deflection panel 10 changes from the second state to the initial state, the refractive index of the liquid crystal 60 for linearly polarized light L1 changes uniformly from the ordinary refractive index no to the extraordinary refractive index ne due to the change in the orientation state of the liquid crystal 60, but no deflection action is exerted in the liquid crystal optical deflection panel 10.

[0039] The following describes in detail the response time τoff from a deflection state (a state where the liquid crystal functions as a lenticular lens) to a non-deflection state (a state where the liquid crystal does not function as a lenticular lens) and the voltage Vs applied to the liquid crystal 60, using an example in which the refractive index anisotropy Δn of the liquid crystal 60 is 0.2 (extraordinary refractive index n e: 1.71, ordinary refractive index n o: 1.51, 589 nm), the dielectric anisotropy Δε of the liquid crystal 60 is 8.9, the thickness of the liquid crystal 60 is 100 μm, and the width of the first electrode 40 is 6.25 μm, forming one lenticular lens (lens pitch: 300 μm) with 17 first electrodes 40 aligned in the X direction. The following description is based on a simulation (LCD Master liquid crystal simulator manufactured by Shintech Co., Ltd.).

[0040] First, the response time τoff will be described. Here, the potential of the second electrode 50 was set to ground potential, and the potentials of the first through seventeenth first electrodes 40, ordered from the -X direction, were controlled to the potentials shown in FIG. 14 . A predetermined electric field was applied to the liquid crystal 60, thereby creating a first state in which the liquid crystal 60 exhibits a deflecting effect. After creating the first state, the potentials of the first through seventeenth first electrodes 40 were set to 10 V (voltage Vs applied to the liquid crystal 60: 10 V), thereby driving at least a portion of the liquid crystal 60 toward the +Z direction and creating a second state in which the liquid crystal 60 does not exhibit a deflecting effect. When changing from the first state to the second state, the refractive index distribution for linearly polarized light L1 changes as shown in FIG. 15 . The response time τoff from the deflecting state to the non-deflecting state was defined as the time it took for the difference between the maximum and minimum values ​​of the refractive index for linearly polarized light L1 to become 0.005. The response time τoff of the liquid crystal optical deflector 100 was 1 second.

[0041] On the other hand, in the same manner as above, when the first state exhibiting a deflection effect is formed, and then the potentials of the 1st to 17th first electrodes 40 are set to ground potential to form an initial state exhibiting no deflection effect (hereinafter referred to as Comparative Example 1), the refractive index distribution for linearly polarized light L1 changes as shown in Fig. 16. The response time τoff of Comparative Example 1 was 25 seconds.

[0042] As described above, by switching the state of the liquid crystal optical deflection panel 10 from the first state in which a deflection effect is exerted to the second state in which a deflection effect is not exerted, the response time τoff from the state in which a deflection effect is exerted to the state in which a deflection effect is not exerted can be shortened.

[0043] Next, the voltage Vs applied to the liquid crystal 60 when changing from a first state in which deflection is exerted to a second state in which deflection is not exerted will be described. Fig. 17 shows the relationship between the voltage Vs and the response time τoff of the liquid crystal optical deflection device 100. As shown in Fig. 17, under the above conditions of the liquid crystal 60, the first electrodes 40, etc., if the voltage Vs is set to 2.2V or higher, the response time τoff of the liquid crystal optical deflection device 100 can be made shorter than the response time τoff of Comparative Example 1. When the voltage Vs is set to 2.2V (the potential of the second electrode is ground potential, and the potentials of the 1st to 17th first electrodes 40 are 2.2V), the refractive index distribution for linearly polarized light L1 changes as shown in Fig. 18.

[0044] 19, the driving process of the liquid crystal optical deflection device 100 will be described. First, when power is supplied to the liquid crystal optical deflection device 100, the control unit 90 resets the state of the liquid crystal optical deflection panel 10 to an initial state. After that, the control unit 90 receives a signal indicating the presence or absence of a deflection action from an external device (for example, the control unit of the liquid crystal display panel 200) (step S110).

[0045] Next, the control unit 90 determines the received signal (step S120). If the received signal indicates "deflection effect present" (step S120; YES), the control unit 90 determines the state of the liquid crystal optical deflection panel 10 before receiving the signal (step S130).

[0046] If the liquid crystal optical deflection panel 10 is in the initial state or the second state before receiving the signal (step S130: initial state or second state), the control unit 90 applies a predetermined electric field to the liquid crystal 60 of the liquid crystal optical deflection panel 10 to drive the liquid crystal 60 in a direction perpendicular to the initial alignment direction, thereby switching the state of the liquid crystal optical deflection panel 10 from the initial state or the second state to the first state (a state in which the liquid crystal optical deflection panel 10 functions as a lenticular lens) in which the liquid crystal 60 deflects the linearly polarized light L1 (step S140). The predetermined electric field drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60, thereby generating a refractive index distribution in the liquid crystal 60 according to the deflection effect. If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S150; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the driving process from an external device (step S150; NO), the driving process of the liquid crystal optical deflection device 100 returns to receiving a signal indicating the presence or absence of deflection action (step S110), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state until it receives the next signal.

[0047] If the state of the liquid crystal optical deflection panel 10 before receiving the signal is the first state (step S130: first state), the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state (step S160). If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S150; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S150; NO), the drive process of the liquid crystal optical deflection device 100 returns to receiving a signal indicating the presence or absence of deflection action (step S110), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state until receiving the next signal.

[0048] If the received signal indicates "no deflection effect" (step S120; NO), the control unit 90 determines the state of the liquid crystal optical deflection panel 10 before receiving the signal (step S170). If the state of the liquid crystal optical deflection panel 10 before receiving the signal is the initial state or the second state (step S170: initial state or second state), the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 (initial state or second state) (step S180). If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S150; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S150; NO), the drive process of the liquid crystal optical deflection device 100 returns to receiving a signal indicating the presence or absence of deflection effect (step S110), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 until it receives the next signal.

[0049] If the state of the liquid crystal optical deflection panel 10 before receiving the signal is the first state (step S170: first state), the control unit 90 applies a uniform electric field to the liquid crystal 60 to drive the liquid crystal 60 in the same direction as the direction in which the liquid crystal 60 is driven (a direction perpendicular to the initial alignment direction) to form the first state from the initial state by controlling the potentials of the plurality of first electrodes 40 and the second electrode 50. As a result, the control unit 90 switches the state of the liquid crystal optical deflection panel 10 from the first state to a second state (a state in which the liquid crystal optical deflection panel 10 does not function as a lenticular lens) in which it does not deflect the linearly polarized light L1 (step S190). If the control unit 90 receives a signal indicating the end of the driving process from an external device (step S150; YES), the driving process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the driving process from an external device (step S150; NO), the driving process of the liquid crystal optical deflection device 100 returns to receiving a signal indicating the presence or absence of deflection action (step S110), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the second state until it receives the next signal.

[0050] In the driving process of the liquid crystal optical deflection device 100, the control unit 90 switches the state of the liquid crystal optical deflection panel 10 from a first state in which deflection is exerted to a second state in which deflection is not exerted by applying a uniform electric field to the liquid crystal 60 and driving at least a part of the liquid crystal 60 in a direction perpendicular to the initial alignment direction (the same direction as when forming the first state from the initial state). Therefore, compared to returning the state of the liquid crystal optical deflection panel 10 from the first state in which deflection is exerted to the initial state in which deflection is not exerted, the driving process of the liquid crystal optical deflection device 100 can shorten the response time from a state in which deflection is exerted to a state in which deflection is not exerted.

[0051] Furthermore, the control unit 90 applies a uniform electric field to the liquid crystal 60 and drives at least a portion of the liquid crystal 60 in a direction perpendicular to the initial alignment direction, thereby uniformly aligning the liquid crystal 60. Therefore, when the state of the liquid crystal optical deflection panel 10 changes from a state in which it has a deflecting effect to a state in which it does not have a deflecting effect, the drive process of the liquid crystal optical deflection device 100 can suppress disturbance in the alignment of the liquid crystal 60. As a result, the drive process of the liquid crystal optical deflection device 100 can suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10.

[0052] As described above, the liquid crystal optical deflection device 100 can shorten the response time from a deflecting state to a non-deflecting state. Furthermore, the liquid crystal optical deflection device 100 can suppress disturbance of the alignment of the liquid crystal 60 when the liquid crystal optical deflection panel 10 transitions from a deflecting state to a non-deflecting state, thereby suppressing unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 can simplify the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90.

[0053] The drive process of the liquid crystal optical deflection device 100 can shorten the response time from a deflection state to a non-deflection state, and can suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10 when the liquid crystal optical deflection panel 10 transitions from a deflection state to a non-deflection state.

[0054] <Embodiment 2> In the first embodiment, the liquid crystal 60 of the liquid crystal light deflection panel 10 is a positive nematic liquid crystal, but the liquid crystal 60 may also be a negative nematic liquid crystal.

[0055] The liquid crystal optical deflection panel 10 of this embodiment includes a liquid crystal 60, which is a negative nematic liquid crystal. The configuration of the liquid crystal optical deflection device 100 of this embodiment is the same as that of the liquid crystal optical deflection device 100 of embodiment 1, except for the orientation state and refractive index distribution of the liquid crystal 60. Here, the orientation state of the liquid crystal 60 and the refractive index distribution of the liquid crystal optical deflection panel 10 will be described.

[0056] The liquid crystal 60 of the liquid crystal optical deflection panel 10 of this embodiment is a negative type nematic liquid crystal, and is oriented in the Z direction by the alignment film 22 and the alignment film 32 .

[0057] In the initial state of the liquid crystal optical deflection panel 10 in this embodiment, the control unit 90 applies no electric field to the liquid crystal 60 by making the potential of the first electrode 40 and the potential of the second electrode 50 the same, thereby maintaining the liquid crystal 60 in the initial alignment state (alignment in the Z direction) shown in Fig. 20. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction becomes uniform (a state in which the refractive index for linearly polarized light L1 is constant at the ordinary refractive index no of the liquid crystal 60) as shown in Fig. 21, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0058] In the first state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a predetermined electric field to the liquid crystal 60, as in the first embodiment, to orient the liquid crystal 60 in a predetermined manner. Specifically, the control unit 90 sets the potential of the second electrode 50 to ground potential and sets the potentials of the first electrodes 40a and 40e shown in FIG. 22 to potentials ±Va1 and ±Ve1 that cause a refractive index distribution in the liquid crystal 60 according to the deflection action. The control unit 90 also sets the potentials of the first electrodes 40b and 40d to potentials ±Vb1 and ±Vd1 that cause a refractive index distribution in the liquid crystal 60 according to the deflection action, and sets the potential of the first electrode 40c to potential ±Vc1 that causes a refractive index distribution in the liquid crystal 60 according to the deflection action. The magnitudes of the potentials ±Va1 to ±Ve1 are in the following order: absolute value of ±Vc1 > absolute value of ±Vb1 = absolute value of ±Vd1 > absolute value of ±Va1 = absolute value of ±Ve1. As a result, a predetermined electric field is applied to the liquid crystal 60, and the liquid crystal 60 is driven in the +Y direction. Then, as shown in Fig. 22, the tilt of the liquid crystal molecules with respect to the +Z direction increases from first electrode 40a to first electrode 40c, and also the tilt of the liquid crystal molecules with respect to the +Z direction increases from first electrode 40e to first electrode 40c. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 with respect to linearly polarized light L1 polarized in the Y direction changes at a predetermined period along the X direction, as shown in Fig. 23, and the liquid crystal optical deflection panel 10 functions as a lenticular lens array extending in the Y direction and arranged in the X direction.

[0059] In the second state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a uniform electric field to the liquid crystal 60 in the same direction as the direction in which the liquid crystal 60 is driven to change from the initial state to the first state, as in the first embodiment. As a result, at least a portion of the liquid crystal 60 is driven in the same direction (a direction perpendicular to the initial alignment direction) as when changing from the initial state to the first state. Specifically, the potential of the second electrode is set to ground potential, and the potentials of the first electrodes 40a to 40e are set to the same predetermined potential (for example, a potential that aligns the liquid crystal 60 in the Y direction). As a result, at least a portion of the liquid crystal 60 is driven in the +Y direction, and the liquid crystal molecules are aligned in, for example, the Y direction, resulting in a uniform alignment of the liquid crystal 60 (FIG. 24). In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 becomes uniform (the refractive index for linearly polarized light L1 is constant at the extraordinary refractive index ne of the liquid crystal 60) as shown in Figure 25, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0060] In this embodiment, the control unit 90 also applies a uniform electric field to the liquid crystal 60 and drives at least a portion of the liquid crystal 60 in a direction perpendicular to the initial alignment direction (the same direction as when the first state is formed from the initial state). This switches the state of the liquid crystal optical deflection panel 10 from a first state in which deflection is achieved to a second state in which deflection is not achieved. This allows the liquid crystal optical deflection device 100 to shorten the response time from a state in which deflection is achieved to a state in which deflection is not achieved. Furthermore, the control unit 90 applies a uniform electric field to the liquid crystal 60 and drives at least a portion of the liquid crystal 60 in a direction perpendicular to the initial alignment direction, thereby aligning the liquid crystal 60 uniformly. This allows the liquid crystal optical deflection device 100 to suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 allows for a simplified electrode configuration of the liquid crystal optical deflection panel 10 and a simplified configuration of the control unit 90.

[0061] <Embodiment 3> In the first embodiment, the liquid crystal 60 of the liquid crystal optical deflection panel 10 is aligned in the Y direction. The liquid crystal 60 of the liquid crystal optical deflection panel 10 may be aligned in a TN (Twisted Nematic) orientation.

[0062] The configuration of the liquid crystal optical deflector 100 of this embodiment is the same as that of the liquid crystal optical deflector 100 of embodiment 1, except for the orientation state of the liquid crystal 60 and the refractive index distribution of the liquid crystal optical deflector panel 10. Here, the orientation state of the liquid crystal 60 and the refractive index distribution of the liquid crystal optical deflector panel 10 will be described.

[0063] The liquid crystal 60 of the liquid crystal optical deflection panel 10 of this embodiment is a positive nematic liquid crystal, and is oriented at 90° TN by the alignment film 22 and the alignment film 32. In this embodiment, the alignment film 22 aligns the liquid crystal 60 in the Y direction, and the alignment film 32 aligns the liquid crystal in the X direction.

[0064] In the initial state of the liquid crystal optical deflection panel 10 in this embodiment, the control unit 90 applies no electric field to the liquid crystal 60 by making the potential of the first electrode 40 and the potential of the second electrode 50 the same, thereby maintaining the liquid crystal 60 in the initial alignment state (TN alignment) shown in Fig. 26. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 having a polarization direction in the Y direction becomes uniform (a state in which the refractive index for linearly polarized light L1 is a constant value between the ordinary refractive index no and the extraordinary refractive index ne of the liquid crystal 60) as shown in Fig. 27, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0065] In the first state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a predetermined electric field to the liquid crystal 60, as in the first embodiment, to orient the liquid crystal 60 in a predetermined manner. Specifically, the control unit 90 sets the potential of the second electrode 50 to ground potential and sets the potentials of the first electrodes 40a and 40e shown in FIG. 28 to potentials ±Va1 and ±Ve1 that cause a refractive index distribution in the liquid crystal 60 according to the deflection action. The control unit 90 also sets the potentials of the first electrodes 40b and 40d to potentials ±Vb1 and ±Vd1 that cause a refractive index distribution in the liquid crystal 60 according to the deflection action, and sets the potential of the first electrode 40c to potential ±Vc1 that causes a refractive index distribution in the liquid crystal 60 according to the deflection action. The magnitudes of the potentials ±Va1 to ±Ve1 are in the following order: absolute value of ±Va1 = absolute value of ±Ve1 > absolute value of ±Vb1 = absolute value of ±Vd1 > absolute value of ±Vc1. As a result, a predetermined electric field is applied to the liquid crystal 60, and the liquid crystal 60 is driven in the +Z direction. Then, as shown in Fig. 28, the twist of the liquid crystal 60 decreases from the first electrode 40c toward the first electrode 40a, and also decreases from the first electrode 40c toward the first electrode 40e. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction changes at a predetermined period along the X direction, as shown in Fig. 29, and the liquid crystal optical deflection panel 10 functions as a lenticular lens array extending in the Y direction and arranged in the X direction.

[0066] In the second state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a uniform electric field to the liquid crystal 60 to drive the liquid crystal 60 in the same direction as the direction in which the liquid crystal 60 is driven to change from the initial state to the first state, as in the first embodiment. As a result, at least a portion of the liquid crystal 60 is driven in the same direction (perpendicular to the initial alignment direction) as when changing from the initial state to the first state. Specifically, the potential of the second electrode is set to ground potential, and the potentials of the first electrodes 40a to 40e are set to the same predetermined potential (for example, a potential that aligns the liquid crystal 60 in the Z direction). As a result, as in the second state of the first embodiment, at least a portion of the liquid crystal 60 is driven in the +Z direction, and the liquid crystal molecules are aligned in, for example, the Z direction, resulting in a uniform alignment of the liquid crystal 60 (FIG. 11). In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 becomes uniform (the refractive index for linearly polarized light L1 is constant at the ordinary refractive index no of the liquid crystal 60) as shown in Figure 12, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0067] In this embodiment, as in the first and second embodiments, the liquid crystal optical deflection device 100 can shorten the response time from a state in which a deflection effect is exerted to a state in which a deflection effect is not exerted. The liquid crystal optical deflection device 100 can suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 can simplify the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90.

[0068] <Embodiment 4> In the first embodiment, one second electrode 50 is provided on the first main surface 30a of the second substrate 30, and the second electrode has a rectangular shape. The second electrode 50 may be a plurality of linear electrodes provided on the first main surface 30a of the second substrate 30 and extending in a direction intersecting with the first electrode 40.

[0069] The liquid crystal optical deflection panel 10 of this embodiment functions as a lenticular lens array extending in the Y direction and arranged in the X direction, similar to the liquid crystal optical deflection panel 10 of embodiment 1. The liquid crystal optical deflection panel 10 of this embodiment also functions as a lenticular lens array extending in the X direction and arranged in the Y direction. In this embodiment, the configuration of the second electrode 50 of the liquid crystal optical deflection panel 10 and the deflection action of the liquid crystal optical deflection panel 10 are different from those of the second electrode 50 and the deflection action of embodiment 1. The other configurations of the liquid crystal optical deflection device 100 of this embodiment are the same as those of embodiment 1. Here, the second electrode 50 and the deflection action will be described.

[0070] 30, the second electrodes 50 of this embodiment are provided on the first main surface 30a of the second substrate 30 and are a plurality of linear electrodes extending in the X direction intersecting the first electrodes 40. The second electrodes 50 have a rectangular shape, extend along the X direction, and are arranged at predetermined intervals in the Y direction. The other configurations of the second electrodes 50 of this embodiment are similar to those of the first electrodes 40 of the first embodiment.

[0071] When the liquid crystal optical deflection panel 10 of this embodiment functions as a lenticular lens array extending in the Y direction and arranged in the X direction, the operation of the liquid crystal optical deflection device 100 of this embodiment is the same as the operation of the liquid crystal optical deflection device 100 of embodiment 1. Here, the case where the liquid crystal optical deflection panel 10 of this embodiment functions as a lenticular lens array extending in the X direction and arranged in the Y direction will be described.

[0072] The initial state of the liquid crystal optical deflection panel 10 in this embodiment is the same as the initial state of the liquid crystal optical deflection panel 10 in embodiment 1 (FIG. 6). The control unit 90 applies no electric field to the liquid crystal 60 by setting the potential of the first electrode 40 and the potential of the second electrode 50 to the same potential, thereby maintaining the liquid crystal 60 in its initial alignment state (alignment in the Y direction). In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction becomes uniform (a state in which the refractive index for linearly polarized light L1 is constant at the extraordinary refractive index ne of the liquid crystal 60) as shown in FIG. 31, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0073] In the first state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a predetermined electric field to the liquid crystal 60, as in the first embodiment, to orient the liquid crystal 60 in a predetermined manner. Specifically, the control unit 90 sets the potential of the first electrode 40 to the ground potential, and sets the potentials of the second electrodes 50a and 50e shown in FIG. 32 to potentials ±Va2 and ±Ve2 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action (FIG. 33). The control unit 90 also sets the potentials of the second electrodes 50b and 50d to potentials ±Vb2 and ±Vd2 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action, and sets the potential of the second electrode 50c to potential ±Vc2 that causes the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action (FIG. 33). The magnitudes of the potentials ±Va2 to ±Ve2 are in the following order: absolute value of ±Va2 = absolute value of ±Ve2 > absolute value of ±Vb2 = absolute value of ±Vd2 > absolute value of ±Vc2. As a result, a predetermined electric field is applied to the liquid crystal 60, driving the liquid crystal 60 in the +Z direction. As shown in FIG. 32, the liquid crystal molecules increase in the +Z direction from the second electrode 50c toward the second electrode 50a relative to the first major surface 20a of the first substrate 20, and also increase in the +Z direction from the second electrode 50c toward the second electrode 50e relative to the first major surface 20a of the first substrate 20. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction changes periodically along the Y direction, as shown in FIG. 34. The liquid crystal optical deflection panel 10 functions as a lenticular lens array extending in the X direction and arranged in the Y direction.

[0074] The second state of the liquid crystal optical deflection panel 10 in this embodiment is similar to the second state of the liquid crystal optical deflection panel 10 in embodiment 1 (FIG. 11). As in embodiment 1, the control unit 90 applies a uniform electric field to the liquid crystal 60 to drive the liquid crystal 60 in the same direction as the direction in which the liquid crystal 60 is driven to change from the initial state to the first state. As a result, at least a portion of the liquid crystal 60 is driven in the same direction (perpendicular to the initial alignment direction) as when changing from the initial state to the first state. Specifically, the potential of the first electrode is set to ground potential, and the potentials of the second electrodes 50a to 50e are set to the same predetermined potential (for example, a potential that aligns the liquid crystal 60 in the Z direction). As a result, at least a portion of the liquid crystal 60 is driven in the Z direction, and the liquid crystal molecules are aligned in, for example, the Z direction, resulting in a uniform alignment of the liquid crystal 60. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 becomes uniform (the refractive index for linearly polarized light L1 is constant at the ordinary refractive index no of the liquid crystal 60) as shown in Figure 35, and the liquid crystal optical deflection panel 10 does not function as a lenticular lens array.

[0075] In this embodiment, as in the first to third embodiments, the liquid crystal optical deflection device 100 can shorten the response time from a state in which a deflection effect is exerted to a state in which a deflection effect is not exerted. The liquid crystal optical deflection device 100 can suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 can simplify the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90.

[0076] <Embodiment 5> In the first to fourth embodiments, the liquid crystal optical deflection panel 10 functions as a lenticular lens array. The liquid crystal optical deflection panel 10 may also function as a diffraction grating.

[0077] The liquid crystal optical deflection panel 10 of this embodiment functions as a diffraction grating. The configuration of the liquid crystal optical deflection device 100 of this embodiment is the same as the configuration of the liquid crystal optical deflection device 100 of embodiment 1, except for the alignment state of the liquid crystal 60 (the potential of the first electrode 40) and the refractive index distribution in the first state of the liquid crystal optical deflection panel 10 of this embodiment. Here, the alignment state of the liquid crystal 60 (the potential of the first electrode 40) and the refractive index distribution in the first state of the liquid crystal optical deflection panel 10 of this embodiment will be described.

[0078] In the first state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a predetermined electric field to the liquid crystal 60, as in the first embodiment, to orient the liquid crystal 60 in a predetermined manner. Specifically, the control unit 90 sets the potential of the second electrode 50 to ground potential, sets the potentials of the first electrodes 40a and 40e shown in FIG. 36 to potentials ±Va1 and ±Ve1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action, and sets the potentials of the first electrodes 40b and 40f to potentials ±Vb1 and ±Vf1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action (FIG. 37). Furthermore, the control unit 90 sets the potentials of the first electrodes 40c and 40g to potentials ±Vc1 and ±Vg1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action, and sets the potentials of the first electrodes 40d and 40h to potentials ±Vd1 and ±Vh1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection action (FIG. 37). The magnitudes of the potentials ±Va1 to ±Vh1 are in the following order: absolute value of ±Va1 = absolute value of ±Ve1 > absolute value of ±Vb1 = absolute value of ±Vf1 > absolute value of ±Vc1 = absolute value of ±Vg1 > absolute value of ±Vd1 = absolute value of ±Vh1. As a result, a predetermined electric field is applied to the liquid crystal 60, and the liquid crystal 60 is driven in the +Z direction. Then, as shown in FIG. 36, the liquid crystal molecules rise more in the +Z direction relative to the first major surface 20a of the first substrate 20 from the first electrode 40d toward the first electrode 40a, and the liquid crystal molecules rise more in the +Z direction relative to the first major surface 20a of the first substrate 20 from the first electrode 40h toward the first electrode 40e. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 having a polarization direction in the Y direction is such that a linear refractive index gradient is repeated at a predetermined period along the X direction, as shown in Figure 38, and the liquid crystal optical deflection panel 10 functions as a diffraction grating.

[0079] In this embodiment, as in the first to fourth embodiments, the control unit 90 applies a uniform electric field to the liquid crystal 60 and drives at least a portion of the liquid crystal 60 in a direction perpendicular to the initial alignment direction (the same direction as when forming the first state from the initial state), thereby switching the state of the liquid crystal optical deflection panel 10 from a first state in which deflection is achieved to a second state in which deflection is not achieved. This allows the liquid crystal optical deflection device 100 to shorten the response time from a state in which deflection is achieved to a state in which deflection is not achieved. The liquid crystal optical deflection device 100 can suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 allows for a simplified electrode configuration of the liquid crystal optical deflection panel 10 and a simplified configuration of the control unit 90.

[0080] <Embodiment 6> In the first to fifth embodiments, the first electrode 40 is provided on the first substrate 20, and the second electrode 50 is provided on the second substrate 30. A plurality of electrodes that apply an electric field to the liquid crystal 60 may be provided on either the first substrate 20 or the second substrate 30.

[0081] The liquid crystal optical deflection panel 10 of this embodiment functions as a diffraction grating. The configuration of the liquid crystal optical deflection device 100 of this embodiment is the same as that of the liquid crystal optical deflection device 100 of the first embodiment, except for the plurality of electrodes 80 that apply an electric field to the liquid crystal 60, the orientation state of the liquid crystal 60 (the potential of the electrodes 80), and the refractive index distribution.

[0082] As shown in FIGS. 39 and 40 , a plurality of electrodes 80 that apply an electric field to the liquid crystal 60 are provided on the first main surface 20a of the first substrate 20. The electrodes 80 are linear electrodes that have a rectangular shape and extend along the Y direction, and are arranged at predetermined intervals in the X direction. Each of the electrodes 80 is connected to the control unit 90 via wiring (not shown). An alignment film 22 covers the first main surface 20a of the first substrate 20 and the plurality of electrodes 80. Note that the liquid crystal optical deflection panel 10 of this embodiment does not include electrodes on the second substrate 30.

[0083] The initial state of the liquid crystal optical deflection panel 10 in this embodiment is the same as the initial state of the liquid crystal optical deflection panel 10 in embodiment 1. The control unit 90 maintains the liquid crystal 60 in its initial alignment state (alignment in the Y direction) by maintaining the same potential across the multiple electrodes 80, without applying an electric field to the liquid crystal 60. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 polarized in the Y direction becomes uniform (a state in which the refractive index for linearly polarized light L1 is constant at the extraordinary refractive index ne of the liquid crystal 60), and the liquid crystal optical deflection panel 10 does not function as a diffraction grating.

[0084] In the first state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a predetermined electric field to the liquid crystal 60, as in the first embodiment, to orient the liquid crystal 60 in a predetermined manner. Specifically, for the electrodes 80a to 80h shown in FIG. 41, the control unit 90 equalizes the potential of electrode 80d and the potential of electrode 80e, and sets the potentials in the following order: the absolute value of the difference between the potentials of electrode 80a and electrode 80b, the absolute value of the difference between the potentials of electrode 80b and electrode 80c, the absolute value of the difference between the potentials of electrode 80c and electrode 80d, and the absolute value of the difference between the potentials of electrode 80e and electrode 80f, the absolute value of the difference between the potentials of electrode 80f and electrode 80g, and the absolute value of the difference between the potentials of electrode 80g and electrode 80h. As a result, a predetermined electric field is applied to the liquid crystal 60, and the liquid crystal 60 is driven in the +X direction. 41, the angle of the long axis direction of the liquid crystal molecules with respect to the +Y direction increases from electrode 80d toward electrode 80a, and the angle of the long axis direction of the liquid crystal molecules with respect to the +Y direction increases from electrode 80h toward electrode 80e. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 with respect to linearly polarized light L1 polarized in the Y direction becomes a state in which a linear refractive index gradient is repeated at a predetermined period along the X direction, similar to the refractive index distribution in the first state in embodiment 5 (FIG. 38), and the liquid crystal optical deflection panel 10 functions as a diffraction grating.

[0085] In the second state of the liquid crystal optical deflection panel 10 of this embodiment, the control unit 90 applies a uniform electric field to the liquid crystal 60, as in the first embodiment, to drive at least a portion of the liquid crystal 60 in the same direction (perpendicular to the initial alignment direction) as when forming the first state from the initial state, thereby uniformly aligning the liquid crystal. Specifically, with respect to the electrodes 80a to 80h, the electrodes 80a, 80c, 80e, and 80g are set to the same potential, and the electrodes 80b, 80d, 80f, and 80h are set to the same potential, and a difference is provided between the potentials of the electrodes 80a, 80c, 80e, and 80g and the potentials of the electrodes 80b, 80d, 80f, and 80h. As a result, at least a portion of the liquid crystal 60 is driven in the X direction, and as shown in FIG. 42, the liquid crystal molecules are aligned in, for example, the X direction, resulting in a uniform alignment of the liquid crystal 60. In this case, the refractive index distribution of the liquid crystal optical deflection panel 10 for linearly polarized light L1 is uniform (the refractive index for linearly polarized light L1 is constant at the ordinary refractive index no of the liquid crystal 60), and the liquid crystal optical deflection panel 10 does not function as a diffraction grating.

[0086] In this embodiment, as in the first to fourth embodiments, the liquid crystal optical deflection device 100 can shorten the response time from a state in which a deflection effect is exerted to a state in which a deflection effect is not exerted. The liquid crystal optical deflection device 100 can suppress unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 can simplify the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90.

[0087] <Embodiment 7> As described in the first embodiment, the control unit 90 may control the potential of the first electrode 40 and the potential of the second electrode 50, and stop applying a uniform electric field to the liquid crystal 60, thereby switching the state of the liquid crystal optical deflection panel 10 from the second state in which no deflection action is exerted to the initial state in which no deflection action is exerted.

[0088] For example, in the driving process of the liquid crystal optical deflection device 100, as shown in FIG. 43, after step S190 of switching the state of the liquid crystal optical deflection panel 10 from the first state to the second state, the control unit 90 may stop applying a uniform electric field to the liquid crystal 60 to switch the state of the liquid crystal optical deflection panel 10 from the second state to an initial state (a state in which the liquid crystal optical deflection panel 10 does not function as a lenticular lens) in which the panel does not deflect linearly polarized light L1 (step S200). Because the liquid crystal 60 is uniformly oriented in the second state, when the state of the liquid crystal optical deflection panel 10 changes from the second state to the initial state, the refractive index for linearly polarized light L1 changes uniformly, but the liquid crystal optical deflection panel 10 does not deflect the linearly polarized light L1. In the driving process of this embodiment, the state of the liquid crystal optical deflection panel 10 is switched from the second state in which a voltage is applied to the liquid crystal 60 to the initial state in which no voltage is applied to the liquid crystal 60, thereby reducing power consumption.

[0089] After step S200, the driving process of this embodiment proceeds to receiving a signal indicating the end of the driving process (step S150). If the liquid crystal optical deflection panel 10 is in the initial state (step S130: initial state), the control unit 90 applies a predetermined electric field to the liquid crystal 60 of the liquid crystal optical deflection panel 10, driving the liquid crystal 60 in a direction perpendicular to the initial alignment direction, thereby switching the state of the liquid crystal optical deflection panel 10 from the initial state to the first state (step S140). If the liquid crystal optical deflection panel 10 was in the initial state before receiving the signal (step S170: initial state), the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 (step S180).

[0090] <Embodiment 8> In embodiment 1, when the liquid crystal optical deflection panel 10 is made to function as a lenticular lens array, the control unit 90 applies a predetermined electric field to the liquid crystal 60 to drive the liquid crystal 60 in a direction perpendicular to the initial alignment direction, thereby driving the liquid crystal 60 in a direction perpendicular to the initial alignment direction, and orienting the liquid crystal 60 in a predetermined manner, thereby switching to a first state in which the liquid crystal panel 10 exhibits a deflection effect.

[0091] When switching the state of the liquid crystal optical deflection panel 10 from an initial state in which no deflection action is exerted to a first state in which a deflection action is exerted, the control unit 90 may apply a first electric field stronger than a predetermined electric field to the liquid crystal 60, and then apply a predetermined electric field to the liquid crystal 60. The first electric field is an electric field that drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60, and the intensity distribution of the first electric field corresponds to the refractive index distribution of the liquid crystal 60 that produces the deflection action, and the intensity of the first electric field is stronger than the intensity of the predetermined electric field. In other words, when switching the state of the liquid crystal optical deflection panel 10 from the initial state in which no deflection action is exerted to the first state in which a deflection action is exerted, the control unit 90 may perform overdrive driving on the liquid crystal optical deflection panel 10.

[0092] In addition, when the liquid crystal optical deflection panel 10 switches from a state in which no deflection action is exerted while switching from the second state in which no deflection action is exerted to the initial state in which no deflection action is exerted to the first state, the control unit 90 may apply a predetermined electric field to the liquid crystal 60 without applying the first electric field to the liquid crystal 60.

[0093] The configuration of the liquid crystal optical deflection device 100 of this embodiment is the same as the configuration of the liquid crystal optical deflection device 100 of embodiment 1, except for the application of an electric field to the liquid crystal 60 by the control unit 90. Here, the application of an electric field to the liquid crystal 60 by the control unit 90 will be described.

[0094] The control unit 90 of this embodiment, like the control unit 90 of embodiment 1, switches the state of the liquid crystal optical deflection panel 10 by controlling the electric field (voltage) applied to the liquid crystal 60 via multiple first electrodes 40 and second electrodes 50.

[0095] In this embodiment, when switching the state of the liquid crystal light deflection panel 10 from an initial state in which the liquid crystal 60 is in an initial alignment state and does not deflect linearly polarized light L1 to a first state in which the liquid crystal 60 is aligned in a predetermined manner and deflects linearly polarized light L1, the control unit 90 first applies a first electric field to the liquid crystal 60 in the initial alignment state, and then applies a predetermined electric field to the liquid crystal 60. The predetermined electric field is an electric field that drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60 and generates a refractive index distribution in the liquid crystal 60 corresponding to the deflection effect. The first electric field is an electric field (i.e., an overdrive voltage) stronger than the predetermined electric field in accordance with the refractive index distribution of the liquid crystal 60 (i.e., the refractive index distribution corresponding to the deflection effect) that drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60 and generates a deflection effect. Hereinafter, the period during which the first electric field is applied to the liquid crystal 60 will be referred to as period P1, and the period during which the predetermined electric field is applied to the liquid crystal 60 will be referred to as period P2.

[0096] The first electric field and the predetermined electric field will be specifically described using the first electrodes 40a to 40e and the second electrode 50 shown in Fig. 8 as examples. First, the control unit 90 of this embodiment sets the potential of the second electrode 50 to the ground potential during period P1, and also sets the potentials of the first electrodes 40a and 40e to potentials ±Va3 and ±Ve3 that have absolute values ​​greater than the potentials ±Va1 and ±Ve1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection effect, in accordance with the refractive index distribution of the liquid crystal 60 that causes the deflection effect, as shown in Fig. 44. The control unit 90 of this embodiment sets the potentials of the first electrodes 40b and 40d to potentials ±Vb3 and ±Vd3, which have absolute values ​​greater than the potentials ±Vb1 and ±Vd1 that cause the liquid crystal 60 to have a refractive index distribution corresponding to the deflection effect, in accordance with the refractive index distribution of the liquid crystal 60 that causes the deflection effect. The control unit 90 of this embodiment sets the potential of the first electrode 40c to potential ±Vc3, which has absolute value greater than the potential ±Vc1 that causes the liquid crystal 60 to have a refractive index distribution corresponding to the deflection effect, in accordance with the refractive index distribution of the liquid crystal 60 that causes the deflection effect. The magnitudes of the potentials ±Va3 to ±Ve3 are in the following order: absolute values ​​of ±Va3 and ±Ve3 > absolute values ​​of ±Vb3 and ±Vd3 > absolute value of ±V3c. As a result, the control unit 90 of this embodiment applies a first electric field to the liquid crystal 60.

[0097] Next, during period P2, the control unit 90 of this embodiment sets the potential of the second electrode 50 to ground potential and sets the potentials of the first electrodes 40a and 40e to potentials ±V1a and ±Ve1 that generate a refractive index distribution in the liquid crystal 60 according to the deflection action. The control unit 90 also sets the potentials of the first electrodes 40b and 40d to potentials ±Vb1 and ±Vd1 that generate a refractive index distribution in the liquid crystal 60 according to the deflection action, and sets the potential of the first electrode 40c to potential ±Vc1 that generates a refractive index distribution in the liquid crystal 60 according to the deflection action. The magnitudes of the potentials ±Va1 to ±Ve1 are in the following order: absolute value of ±Va1 = absolute value of ±Ve1 > absolute value of ±Vb1 = absolute value of ±Vd1 > absolute value of ±Vc1. As a result, the control unit 90 of this embodiment applies a predetermined electric field to the liquid crystal 60 that generates a refractive index distribution in the liquid crystal 60 according to the deflection action.

[0098] Below, based on the results of a simulation, the refractive index distribution for linearly polarized light L1 and the response time τon from the initial state in which there is no deflection effect on linearly polarized light L1 to the first state in which there is a deflection effect on linearly polarized light L1 will be described. The configuration of the liquid crystal optical deflection panel 10 (first electrode 40, liquid crystal 60) in this simulation is the same as the configuration of the liquid crystal optical deflection panel 10 in the simulation of embodiment 1.

[0099] In this simulation, the period P1 was set to 1 second (P1=1 sec.). The potential of the second electrode 50 was set to ground potential, and the potentials of the first to seventeenth first electrodes 40 were controlled to the potentials shown in Fig. 45, thereby applying a first electric field (overdrive voltage: 4.3 V to 10.0 V) to the liquid crystal 60 of the liquid crystal optical deflection panel 10 in the initial state (the liquid crystal 60 in the initial alignment state). Next, in the period P2, the potentials of the first to seventeenth first electrodes 40 were controlled to the predetermined potentials shown in Fig. 14, thereby forming the first state as in the first embodiment.

[0100] When the liquid crystal optical deflection panel 10 of the embodiment was changed from the initial state not exhibiting a deflection effect to the first state exhibiting a deflection effect, the refractive index distribution for linearly polarized light L1 changed as shown in Fig. 46. The difference between the maximum and minimum values ​​of the refractive index distribution of the liquid crystal 60 in the first state exhibiting a deflection effect was set to 100%, and the difference between the refractive index distribution value in the first state and the refractive index distribution value at each time was calculated. The response time τon from the initial state not exhibiting a deflection effect to the first state exhibiting a deflection effect was set to the time when the maximum value of the obtained difference became 10% (0.015 in this simulation).

[0101] On the other hand, when the control unit 90 applies a predetermined electric field to the liquid crystal 60 in the initial alignment state to switch the state of the liquid crystal optical deflection panel 10 from the initial state in which no deflection action is exerted to the first state in which deflection action is exerted (hereinafter referred to as Comparative Example 2), the refractive index distribution for the linearly polarized light L1 changed as shown in Fig. 47. The response time τon of Comparative Example 2 was 20 seconds.

[0102] As described above, by applying a first electric field to the liquid crystal 60 in the initial orientation state and then applying a predetermined electric field to the liquid crystal 60, the state of the liquid crystal optical deflection panel 10 is switched from the initial state in which no deflection action is exerted to the first state in which deflection action is exerted, thereby shortening the response time τon for switching from the initial state to the first state.

[0103] In this embodiment, when switching the state of the liquid crystal light deflection panel 10 from a first state in which the liquid crystal 60 is aligned in a predetermined manner and deflects linearly polarized light L1 to a state in which the liquid crystal 60 does not deflect linearly polarized light L1, the control unit 90 switches the state of the liquid crystal light deflection panel 10 from the first state to a second state, and then from the second state to the initial state, as in embodiment 7. The second state is a state in which at least a portion of the liquid crystal 60 is driven by a uniform electric field in a direction perpendicular to the initial alignment direction, so that the liquid crystal 60 is aligned uniformly, the refractive index distribution is uniform, and the liquid crystal 60 does not deflect light. Switching from the first state to the second state and switching from the second state to the initial state in this embodiment are similar to embodiments 1 and 7.

[0104] When the control unit 90 stops applying the uniform electric field to the liquid crystal 60, the state of the liquid crystal optical deflection panel 10 is switched from the second state to the initial state. Hereinafter, the state in which no deflection action is exerted, which is in the middle of switching from the second state in which no deflection action is exerted to the initial state in which no deflection action is exerted, will be referred to as the third state. Figure 48 shows an example of the alignment state of the liquid crystal 60 in the third state.

[0105] In this embodiment, when switching the state of the liquid crystal optical deflection panel 10 from the third state in which no deflection action is exerted to the first state in which deflection action is exerted, the control unit 90 of this embodiment applies a predetermined electric field to the liquid crystal 60 without applying the first electric field to the liquid crystal 60. In other words, when switching the state of the liquid crystal optical deflection panel 10 from the third state in which no deflection action is exerted to the first state in which deflection action is exerted, the control unit 90 of this embodiment does not overdrive the liquid crystal optical deflection panel 10.

[0106] The third state of the liquid crystal optical deflection panel 10 is a state in the middle of switching from the second state, in which no deflection action is exerted, to the first state, in which no deflection action is exerted. As described in the first embodiment, in the third state, the orientation state of the liquid crystal 60 changes, and the refractive index of the liquid crystal 60 for linearly polarized light L1 uniformly changes from the ordinary refractive index no to the extraordinary refractive index ne. However, the third state does not exert a deflection action. In the third state, the orientation state of the liquid crystal 60 varies depending on the time elapsed since the application of the uniform electric field to the liquid crystal 60 was stopped (hereinafter referred to as the elapsed time SP). Therefore, if the same first electric field is applied to the liquid crystal 60 regardless of the elapsed time SP, the liquid crystal 60 may be overdriven, resulting in a long response time τon. Therefore, in this embodiment, when switching the state of the liquid crystal optical deflection panel 10 from the third state to the first state, the control unit 90 applies a predetermined electric field to the liquid crystal 60 without applying the first electric field to the liquid crystal 60.

[0107] Below, based on a simulation, the refractive index distribution for linearly polarized light L1 and the response time τon from the third state, in which there is no deflection effect on linearly polarized light L1, to the first state, in which there is a deflection effect on linearly polarized light L1, will be described. The configuration of the liquid crystal optical deflection panel 10 (first electrode 40, liquid crystal 60) in this simulation is the same as the configuration of the liquid crystal optical deflection panel 10 in the simulation of embodiment 1.

[0108] In this simulation, similar to the simulation of the first embodiment, the potential of the second electrode 50 was set to ground potential, and the potentials of the first to seventeenth first electrodes 40, ordered from the −X direction, were controlled to the potentials shown in FIG. 14 to form a first state exhibiting a deflection effect. Then, the potentials of the first to seventeenth first electrodes 40 were set to 10 V to form a second state (the potentials of the first to seventeenth first electrodes 40 were set to 10 V for two seconds). Next, the potentials of the first to seventeenth first electrodes 40 were set to ground potential to stop the application of the uniform electric field to the liquid crystal 60. Ten seconds after the application of the uniform electric field to the liquid crystal 60 was stopped, the potentials of the first to seventeenth first electrodes 40 were controlled to the potentials shown in FIG. 14 to form the first state exhibiting a deflection effect. That is, by applying a predetermined electric field to the liquid crystal 60 of the liquid crystal optical deflection panel 10 in the third state after an elapsed time SP of 10 seconds, the state of the liquid crystal optical deflection panel 10 was switched from the third state to the first state without performing overdrive driving.

[0109] As a result, the refractive index distribution for linearly polarized light L1 changed as shown in Fig. 49. The response time τon from the third state to the first state was 15 seconds.

[0110] In addition, as Comparative Example 3, the potentials of the 1st to 17th first electrodes 40 were controlled to the potentials shown in Fig. 45 10 seconds after the application of the electric field to the liquid crystal 60 was stopped, and then the first electric field was applied to the liquid crystal 60 for 1 second, and the potentials of the 1st to 17th first electrodes 40 were controlled to the predetermined potentials shown in Fig. 14 to form the first state. That is, the first electric field and the predetermined electric field were applied to the liquid crystal 60 of the liquid crystal optical deflection panel 10, which was in the third state after the elapsed time SP of 10 seconds, to perform overdrive driving, and the state of the liquid crystal optical deflection panel 10 was switched from the third state to the first state.

[0111] As a result, the refractive index distribution for linearly polarized light L1 changed as shown in Figure 50. The response time τon from the third state to the first state was 25 seconds. As described above, if overdrive driving is performed when the liquid crystal optical deflection panel 10 is in the third state, the liquid crystal 60 may be excessively driven, which may lengthen the response time τon.

[0112] 51, the driving process of the liquid crystal optical deflection device 100 will be described. First, as in the first embodiment, when power is supplied to the liquid crystal optical deflection device 100, the control unit 90 resets the state of the liquid crystal optical deflection panel 10 to an initial state. After that, the control unit 90 receives a signal indicating the presence or absence of a deflection action from an external device (step S810).

[0113] Next, the control unit 90 determines the received signal (step S820). If the received signal indicates "no deflection" (step S820; NO), the control unit 90 determines the state of the liquid crystal optical deflection panel 10 before receiving the signal (step S830). If the state of the liquid crystal optical deflection panel 10 before receiving the signal is the initial state (step S830: initial state), the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 (step S832). If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S840; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S840; NO), the drive process of the liquid crystal optical deflection device 100 returns to receiving the signal indicating the presence or absence of deflection (step S810), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 until it receives the next signal.

[0114] If the liquid crystal optical deflection panel 10 is in the first state before receiving the signal (step S830: first state), the control unit 90 applies a uniform electric field to the liquid crystal 60 to drive the liquid crystal 60 in the same direction (perpendicular to the initial alignment direction) as the direction in which the liquid crystal 60 is driven to change from the initial state to the first state by controlling the potentials of the first electrodes 40 and the second electrodes 50. This causes the control unit 90 to switch the state of the liquid crystal optical deflection panel 10 from the first state to a second state in which the liquid crystal 60 does not deflect the linearly polarized light L1 (step S834). Next, the control unit 90 stops applying the uniform electric field to the liquid crystal 60, thereby switching the state of the liquid crystal optical deflection panel 10 from the second state to the initial state in which the liquid crystal 60 does not deflect the linearly polarized light L1 (step S836). Furthermore, the control unit 90 measures the time elapsed since the application of the electric field to the liquid crystal 60 was stopped, i.e., the elapsed time SP (step S838).

[0115] If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S840; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S840; NO), the drive process of the liquid crystal optical deflection device 100 returns to the reception of a signal indicating the presence or absence of deflection action (step S810), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the initial state until the control unit 90 receives the next signal.

[0116] If the received signal indicates that deflection is enabled (step S820; YES), the control unit 90 determines whether the state of the liquid crystal optical deflection panel 10 before receiving the signal was the first state (step S850). If the state of the liquid crystal optical deflection panel 10 before receiving the signal was the first state (step S850; YES), the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state (step S852). If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S840; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S840; NO), the drive process of the liquid crystal optical deflection device 100 returns to the reception of the signal indicating the presence or absence of deflection (step S810), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state until it receives the next signal.

[0117] If the state of the liquid crystal optical deflection panel 10 before receiving the signal is not the first state (step S850; NO), the control unit 90 determines whether the elapsed time SP is shorter than the time it takes for the state of the liquid crystal optical deflection panel 10 to change from the second state to the initial state (hereinafter referred to as the arrival time τa) or whether it is greater than or equal to the arrival time τa (step S854). The arrival time τa is determined in advance by experiment or simulation and stored in the ROM 93 of the control unit 90. If the elapsed time SP is shorter than the arrival time τa (step S854: SP<τa), the state of the liquid crystal optical deflection panel 10 is the third state, and the control unit 90 applies a predetermined electric field to the liquid crystal 60 to switch the state of the liquid crystal optical deflection panel 10 from the third state, in which the liquid crystal optical deflection panel 10 does not deflect the linearly polarized light L1, to the first state, in which the liquid crystal optical deflection panel 10 deflects the linearly polarized light L1 (step S856). The predetermined electric field is an electric field that drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60, and generates a refractive index distribution in the liquid crystal 60 according to the deflection action.

[0118] If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S840; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S840; NO), the drive process of the liquid crystal optical deflection device 100 returns to receiving a signal indicating the presence or absence of deflection action (step S810), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state until it receives the next signal.

[0119] If the elapsed time SP is equal to or greater than the arrival time τa (step S854: SP≧τa), the liquid crystal optical deflection panel 10 is in the initial state, so the control unit 90 applies a first electric field to the liquid crystal 60 for a predetermined period (period P1) (step S858). Next, by applying a predetermined electric field to the liquid crystal 60, the state of the liquid crystal optical deflection panel 10 is switched from the initial state, in which the liquid crystal optical deflection panel 10 does not deflect the linearly polarized light L1, to a first state, in which the liquid crystal optical deflection panel 10 deflects the linearly polarized light L1 (step S859). The first electric field is stronger than the predetermined electric field, and drives the liquid crystal 60 in a direction perpendicular to the initial alignment direction of the liquid crystal 60, causing the liquid crystal 60 to deflect.

[0120] If the control unit 90 receives a signal indicating the end of the drive process from an external device (step S840; YES), the drive process of the liquid crystal optical deflection device 100 ends. If the control unit 90 does not receive a signal indicating the end of the drive process from an external device (step S840; NO), the drive process of the liquid crystal optical deflection device 100 returns to receiving a signal indicating the presence or absence of deflection action (step S810), and the control unit 90 maintains the state of the liquid crystal optical deflection panel 10 in the first state until it receives the next signal.

[0121] In the driving process of the liquid crystal optical deflection device 100 of this embodiment, after applying a first electric field in step S858, a predetermined electric field is applied to the liquid crystal 60 in step S859, thereby switching the state of the liquid crystal optical deflection panel 10 from an initial state in which no deflection action is exerted to a first state in which deflection action is exerted, thereby shortening the response time τon for switching from the initial state to the first state.

[0122] As described above, in this embodiment, the response time τon required to switch the state of the liquid crystal optical deflection panel 10 from the initial state to the first state can be shortened.

[0123] Furthermore, similar to the liquid crystal optical deflection device 100 of embodiment 1, the liquid crystal optical deflection device 100 of this embodiment can shorten the response time from a deflecting state to a non-deflecting state. The liquid crystal optical deflection device 100 of this embodiment can suppress disturbance of the alignment of the liquid crystal 60 when the liquid crystal optical deflection panel 10 transitions from a deflecting state to a non-deflecting state, thereby suppressing unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 of this embodiment can simplify the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90.

[0124] <Embodiment 9> In the eighth embodiment, when the state of the liquid crystal optical deflection panel 10 is switched from the third state in which no deflection action is exerted to the first state in which deflection action is exerted, the control unit 90 does not perform overdrive driving on the liquid crystal optical deflection panel 10. The control unit 90 may perform overdrive driving on the liquid crystal optical deflection panel 10 in the third state by applying a first electric field to the liquid crystal 60 according to the elapsed time SP.

[0125] The configuration of the liquid crystal optical deflection device 100 of this embodiment is the same as that of the liquid crystal optical deflection device 100 of embodiment 8, except for the configuration for switching the state of the liquid crystal optical deflection panel 10 from the initial state in which no deflection action is exerted or the third state in which no deflection action is exerted to the first state in which deflection action is exerted. Here, the switching from the initial state or the third state to the first state by the control unit 90 will be described.

[0126] In this embodiment, when switching the state of the liquid crystal light deflection panel 10 from the initial state or the third state where no deflection action is exerted to the first state where a deflection action is exerted, the control unit 90 applies a first electric field corresponding to the elapsed time SP to the liquid crystal 60 for a predetermined period (period P1), and then applies a predetermined electric field to the liquid crystal 60. Specifically, when the elapsed time SP is shorter than the arrival time τa, the control unit 90 sets the intensity of the first electric field to be stronger as the elapsed time SP becomes longer. When the elapsed time SP is equal to or longer than the arrival time τa, the intensity of the first electric field may be the same regardless of the elapsed time SP. Thus, suitable overdrive driving can be performed on the liquid crystal light deflection panel 10 in the initial state and the third state. Note that the elapsed time SP is the time elapsed since the application of a uniform electric field to the liquid crystal 60 stopped, and the arrival time τa is the time until the state of the liquid crystal light deflection panel 10 reaches the initial state from the second state.

[0127] Taking the first electrodes 40a to 40e and the second electrode 50 shown in FIG. 8 as an example, the control of the potential of the first electrode 40 and the first electric field will be specifically described. In the period P1, the control unit 90 sets the potential of the second electrode 50 to the ground potential and sets the potentials of the first electrodes 40a to 40e to potentials corresponding to the elapsed time SP shown in FIG. 52.

[0128] FIG. 52 shows the relationship between the elapsed time SP and the potentials of the first electrodes 40a to 40e, and the magnitude relationship of the potentials at each of the elapsed times SP for each of the first electrodes 40a to 40e. For example, when applying the first electric field to the liquid crystal 60 at the elapsed time SP of SPj, the control unit 90 sets the potential of the first electrode 40a to ±Vj-a (j, n: natural numbers). Also, for example, the potential of the first electrode 40a is in the order of Va1 < V1-a < V2-a < ··· < Vj-a ··· < Va3. As the elapsed time SP becomes longer from SP1 to SPn, the control unit 90 sets the absolute value of the potential of each of the first electrodes 40a to 40e to be larger. Thereby, the control unit 90 can increase the intensity of the first electric field as the elapsed time SP becomes longer. The relationship between the elapsed time SP and the potential of the first electrode 40 shown in FIG. 52 is stored in the ROM 93 of the control unit 90 as a look-up table.

[0129] The first electric field at the elapsed time SP0 is similar to a predetermined electric field that generates a refractive index distribution in the liquid crystal 60 according to the deflection action. The potentials Va1 to Ve1 of the first electrodes 40a to 40e shown in FIG. 52 may be similar to the potentials Va1 to Ve1 of the first electrodes 40a to 40e in the first embodiment. At the elapsed time SPn (SPn=τa) that is equal to the arrival time τa, the state of the liquid crystal optical deflection panel 10 is in the initial state. After the elapsed time SPn (i.e., after the state of the liquid crystal optical deflection panel 10 reaches the initial state), the strength of the first electric field may be the same. The strength of the first electric field after the elapsed time SPn may be the same as the strength of the first electric field in the eighth embodiment. Furthermore, the magnitude of the potential of the first electrode 40 within the same elapsed time SP is in the following order: absolute value of the potential of the first electrode 40a = absolute value of the potential of the first electrode 40e > absolute value of the potential of the first electrode 40b = absolute value of the potential of the first electrode 40d > absolute value of the potential of the first electrode 40c.

[0130] The strength of the first electric field (potential of the first electrode 40) is determined in advance by experiment or simulation so as to shorten the response time τon without overdriving the liquid crystal 60.

[0131] The driving process of the liquid crystal optical deflector 100 of this embodiment will be described with reference to Fig. 53. Steps S810 to S852 in the driving process of this embodiment are the same as steps S810 to S852 in the eighth embodiment, so steps S912 and S914 will be described here.

[0132] If the state of the liquid crystal optical deflection panel 10 before receiving the signal is not the first state (step S850; NO), the control unit 90 sets a first electric field according to the elapsed time SP and applies the set first electric field to the liquid crystal 60 for a predetermined period (step S912). Specifically, the control unit 90 sets a first electric field of different strength to the liquid crystal 60 according to the elapsed time SP, based on the relationship between the elapsed time SP and the potential of the first electrode 40 (FIG. 52) stored as a lookup table. The control unit 90 applies the set first electric field to the liquid crystal 60 for a predetermined period. This allows the absolute value of the potential of each of the first electrodes 40a-40e to be set larger as the elapsed time SP increases from SP1 to SPn. Furthermore, after the elapsed time SP reaches SPn, the absolute value of the potential of each of the first electrodes 40a-40e can be set to the same regardless of the elapsed time SP.

[0133] The control unit 90 applies the set first electric field to the liquid crystal 60 for a predetermined period, and then applies a predetermined electric field to the liquid crystal 60, thereby switching the state of the liquid crystal optical deflection panel 10 to the first state (step S914).

[0134] In this embodiment, overdrive driving can be performed on the liquid crystal optical deflection panel 10 in the initial state and the third state, thereby shortening the response time for switching the state of the liquid crystal optical deflection panel 10 from the initial state or the third state to the first state.

[0135] Furthermore, similar to the liquid crystal optical deflection device 100 of embodiment 1, the liquid crystal optical deflection device 100 of this embodiment can shorten the response time from a deflecting state to a non-deflecting state. The liquid crystal optical deflection device 100 of this embodiment can suppress disturbance of the alignment of the liquid crystal 60 when the liquid crystal optical deflection panel 10 transitions from a deflecting state to a non-deflecting state, thereby suppressing unevenness in the optical characteristics of the liquid crystal optical deflection panel 10. Furthermore, the liquid crystal optical deflection device 100 of this embodiment can simplify the electrode configuration of the liquid crystal optical deflection panel 10 and the configuration of the control unit 90.

[0136] <Modification> Although the embodiments have been described above, various modifications can be made to the present disclosure without departing from the spirit and scope of the present disclosure.

[0137] For example, in the first embodiment, the second electrode 50 is a single rectangular electrode. The second electrode 50 may be a plurality of linear electrodes that face each of the first electrodes 40 and extend in the Y direction.

[0138] In the first embodiment, the liquid crystal 60 in an initial alignment state is aligned in the Y direction, and the first electrode 40 extends in the Y direction. That is, the initial alignment direction of the liquid crystal 60 and the extension direction of the first electrode 40 are parallel to each other. The initial alignment direction of the liquid crystal 60 and the extension direction of the first electrode 40 may be different. For example, as shown in FIG. 54, the first electrode 40 in the first embodiment may be tilted counterclockwise at an angle θ with respect to the +Y direction. In this case, the liquid crystal optical deflection panel 10 functions as a lenticular lens array in which the lenticular lenses are tilted at an angle θ with respect to the Y direction.

[0139] In the embodiment, the first electrode 40, the second electrode 50, and the electrode 80 are linear electrodes or rectangular electrodes, but the shapes of the first electrode 40, the second electrode 50, and the electrode 80 are arbitrary. For example, the first electrode 40 provided on the first substrate 20 may be an electrode having a ring shape arranged concentrically as shown in Fig. 55, and the second electrode 50 provided on the second substrate 30 may be rectangular as in the first embodiment. In this case, the liquid crystal optical deflection panel 10 functions as a convex or concave lens.

[0140] In the embodiment, the first electrode 40 or the electrode 80 is provided on the first substrate 20, and the second electrode 50 is provided on the second substrate 30. The arrangement of the first electrode 40, the second electrode 50, and the electrode 80 is not limited to the above. For example, the first electrode 40 or the electrode 80 may be provided on the second substrate 30, and the second electrode 50 may be provided on the first substrate 20.

[0141] When the state of the liquid crystal optical deflection panel 10 switches from the first state to the second state, at least a portion of the liquid crystal 60 needs to be driven in a direction perpendicular to the initial alignment direction. In the second state, the liquid crystal 60 does not need to be uniformly aligned in a direction perpendicular to the initial alignment direction. For example, in the second state of the liquid crystal optical deflection panel 10 in embodiment 1, the liquid crystal 60 may be uniformly aligned at an angle with respect to the +Z direction, as shown in FIG.

[0142] In the ninth embodiment, the control unit 90 applies a first electric field to the liquid crystal 60 for a predetermined period, with the intensity varying depending on the elapsed time SP, and then applies a predetermined electric field to the liquid crystal 60. The control unit 90 may refer to a lookup table (FIG. 57) that changes the period P1 during which the first electric field is applied to the liquid crystal 60 depending on the elapsed time SP. Specifically, if the elapsed time SP is shorter than the arrival time τa, which is the time it takes for the state of the liquid crystal optical deflection panel 10 to reach the initial state, the control unit 90 sets the period P1 during which the first electric field is applied to be longer as the elapsed time SP increases. If the elapsed time SP is equal to or longer than the arrival time τa, the period P1 during which the first electric field is applied may be the same regardless of the elapsed time SP. For example, based on the lookup table shown in FIG. 57, the control unit 90 sets the period P1 during which the first electric field is applied to be longer as the elapsed time SP increases from SP1 to SPn. Furthermore, when the elapsed time SP is after SPn, the control unit 90 sets the length of the period P1 during which the first electric field is applied to be the same (P1=tn) regardless of the elapsed time SP. This also makes it possible to perform suitable overdrive driving on the liquid crystal optical deflection panel 10 in the initial state and the third state, as in the ninth embodiment. The length of the period P1 is determined in advance by experiment or simulation so as to shorten the response time τon without overdriving the liquid crystal 60.

[0143] Furthermore, the control unit 90 may refer to a lookup table (FIG. 58) that changes the strength of the first electric field and the period (period P1) for applying the first electric field according to the elapsed time SP. Specifically, when the elapsed time SP is shorter than the arrival time τa, which is the time it takes for the liquid crystal optical deflection panel 10 to reach its initial state, the control unit 90 sets the strength of the first electric field to be stronger and the period for applying the first electric field to be longer as the elapsed time SP increases. When the elapsed time SP is equal to or longer than the arrival time τa, the strength of the first electric field and the length of the period P1 for applying the first electric field may remain the same regardless of the elapsed time SP. For example, based on the lookup table shown in FIG. 58, the control unit 90 sets the absolute value of the potential of each of the first electrodes 40a to 40e shown in FIG. 8 to be larger and the period P1 for applying the first electric field to be longer as the elapsed time SP increases from SP1 to SPn. When the elapsed time SP is after SPn, the control unit 90 sets the strength of the first electric field and the length of the period P1 during which the first electric field is applied to be the same regardless of the elapsed time SP. This also makes it possible to perform suitable overdrive driving on the liquid crystal optical deflection panel 10 in the initial state and the third state, as in embodiment 9. The strength of the first electric field (potential of the first electrode) and the period P1 are determined in advance by experiment or simulation so as to shorten the response time τon without overdriving the liquid crystal 60.

[0144] Although the preferred embodiments have been described above, the present disclosure is not limited to such specific embodiments, and the present disclosure includes the inventions described in the claims and their equivalents. [Explanation of symbols]

[0145] 10 Liquid crystal light deflection panel, 20 First substrate, 20a First main surface, 20b Second main surface, 22 Alignment film, 30 Second substrate, 30a First main surface, 32 Alignment film, 40, 40a-40h First electrode, 50, 50a-50e Second electrode, 60 Liquid crystal, 70 Silicon material, 80, 80a-80h Electrode, 90 Control unit, 92 CPU, 93 ROM, 94 RAM, 96 Power supply circuit, 98 Input / output input / output circuit, 100 Liquid crystal light deflection device, 200 Liquid crystal display panel, 300 Display device, L1 Linearly polarized light, τon, τoff response time, τa Arrival time, Vs Voltage, ±Va1 to ±Vh1, ±Va2 to ±Ve2, ±Va3 to ±Ve3, V1-a, V2-a, Vj-a, V1-b, V2-b, Vj-b, V1-c, V2-c, Vj-c, V1-d, V2-d, Vj-d, V1-e, V2-e, Vj-e, V1-aa, V2-aa, Vj-aa, V1-bb, V2-bb, Vj-bb, V1-cc, V2-cc, Vj-cc, V1-dd, V2-dd, Vj-dd, V1-ee, V2-ee, Vj-ee Potential, P1, P2, t1, t2, tj, t11, t12, t1j, tn Period, SP Elapsed Time, Δε Dielectric Anisotropy, Δn Refractive index anisotropy, ne abnormal light refractive index, no ordinary light refractive index, θ angle

Claims

1. a liquid crystal optical deflection panel including a first substrate onto which light is incident, a second substrate facing the first substrate, a liquid crystal sandwiched between the first substrate and the second substrate, and a plurality of electrodes for applying an electric field to the liquid crystal; a control unit that controls the deflection action of the liquid crystal light deflection panel on the light, The control unit a predetermined electric field is applied to the liquid crystal to drive the liquid crystal in a direction perpendicular to an initial alignment direction of the liquid crystal, and to the liquid crystal to generate a refractive index distribution corresponding to the deflection effect, thereby bringing the liquid crystal optical deflection panel into a first state in which the deflection effect is exerted; applying a uniform electric field to the liquid crystal, which drives at least a part of the liquid crystal in the direction perpendicular to the initial alignment direction, to switch the state of the liquid crystal optical deflection panel from the first state to a second state in which the deflection action is not exerted; Liquid crystal light deflection device.

2. the control unit switches the state of the liquid crystal optical deflection panel from the second state to an initial state in which the liquid crystal is in an initial orientation state and does not exhibit the deflection effect by stopping the application of the uniform electric field to the liquid crystal.

2. The liquid crystal optical deflector according to claim 1.

3. When switching the state of the liquid crystal optical deflection panel from the initial state to the first state, the control unit drives the liquid crystal in the direction perpendicular to the initial alignment direction of the liquid crystal, applies a first electric field stronger than the predetermined electric field in accordance with the refractive index distribution, and then applies the predetermined electric field to the liquid crystal.

3. The liquid crystal optical deflector according to claim 2.

4. when switching the state of the liquid crystal optical deflection panel from a third state, which is a state during switching from the second state to the initial state, to the first state, the control unit applies the predetermined electric field to the liquid crystal without applying the first electric field.

4. The liquid crystal optical deflector according to claim 3.

5. when switching the state of the liquid crystal optical deflection panel from the initial state or a third state that is a state in the middle of switching from the second state to the initial state to the first state, the control unit drives the liquid crystal in the direction perpendicular to the initial alignment direction of the liquid crystal, applies a first electric field that is stronger than the predetermined electric field in accordance with the refractive index distribution, and then applies the predetermined electric field to the liquid crystal; At least one of the intensity of the first electric field applied to the liquid crystal and the length of the period during which the first electric field is applied to the liquid crystal varies depending on the time elapsed since the application of the uniform electric field to the liquid crystal was stopped.

3. The liquid crystal optical deflector according to claim 2.

6. The plurality of electrodes includes a plurality of first electrodes and a second electrode facing the plurality of first electrodes. The liquid crystal optical deflection device according to claim 1 .

7. Each of the plurality of first electrodes is a linear electrode extending in a predetermined direction.

7. The liquid crystal optical deflector according to claim 6.

8. Each of the plurality of first electrodes has a ring shape and is arranged concentrically.

7. The liquid crystal optical deflector according to claim 6.

9. The plurality of electrodes includes a plurality of first electrodes disposed on one of the first substrate and the second substrate and extending in a predetermined first direction, and a plurality of second electrodes disposed on the other of the first substrate and the second substrate and extending in a second direction intersecting the predetermined first direction. The liquid crystal optical deflection device according to claim 1 .

10. the plurality of electrodes are disposed on one of the first substrate and the second substrate; Each of the plurality of electrodes is a linear electrode extending in a predetermined direction. The liquid crystal optical deflection device according to claim 1 .

11. a step of applying a predetermined electric field to the liquid crystal of the liquid crystal optical deflection panel, which drives the liquid crystal in a direction perpendicular to the initial alignment direction of the liquid crystal, and generates a refractive index distribution in the liquid crystal according to the deflection effect, thereby bringing the state of the liquid crystal optical deflection panel into a first state in which the deflection effect is exhibited; applying a uniform electric field to the liquid crystal, which drives at least a part of the liquid crystal in the direction perpendicular to the initial alignment direction, to switch the state of the liquid crystal optical deflection panel from the first state to a second state in which the deflection effect is not exhibited; A method for driving a liquid crystal optical deflection device.

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