Illumination device and optical element

Abstract

A lighting device includes a light source, a first liquid crystal cell on the light source, and a second liquid crystal cell on the first liquid crystal cell. The first liquid crystal cell and the second liquid crystal cell each include a first substrate, a plurality of first lower electrodes, a plurality of second lower electrodes, a first liquid crystal layer, and a second substrate. The first substrate includes a first region and a second region. The plurality of first lower electrodes are located on the first region and extend in a column direction. The plurality of second lower electrodes are located on the second region and extend in the column direction. The first liquid crystal layer is located on the plurality of first lower electrodes and the plurality of second lower electrodes. The second substrate is located on the first liquid crystal layer. The plurality of first lower electrodes and the plurality of second lower electrodes are independently driven from each other.

Description

Technical Field

[0001] One embodiment of the present invention relates to a lighting device and a driving method thereof. For example, one embodiment of the present invention relates to a lighting device and a driving method thereof capable of displaying patterns such as text and pictures in an area illuminated by light. Background Technology

[0002] There is a known lighting device that can display various texts, pictures, etc. in an area illuminated by light from a light source (hereinafter referred to as the illuminating area) by modulating the light emitted from the light source or by physically blocking a portion of the light (see Patent Documents 1-3).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-145718

[0006] Patent Document 2: Japanese Patent Application Publication No. 2004-62122

[0007] Patent Document 3: Japanese Patent Application Publication No. 2011-44328 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] One of the objectives of one embodiment of the present invention is to provide a lighting device that can display patterns such as text and pictures in an illuminated area by changing the direction of light emission in various ways without increasing power consumption.

[0010] Solutions for solving technical problems

[0011] One embodiment of the present invention is a lighting device. The lighting device includes a light source, a first liquid crystal cell on the light source, and a second liquid crystal cell on the first liquid crystal cell. Each of the first and second liquid crystal cells has a first substrate, a plurality of first lower electrodes, a plurality of second lower electrodes, a first liquid crystal layer, and a second substrate. The first substrate has a first region and a second region. The plurality of first lower electrodes are located on the first region and extend along a column direction. The plurality of second lower electrodes are located on the second region and extend along a column direction. The first liquid crystal layer is located on the plurality of first lower electrodes and the plurality of second lower electrodes. The second substrate is located on the first liquid crystal layer. The plurality of first lower electrodes and the plurality of second lower electrodes are driven independently of each other.

[0012] One embodiment of the present invention is an optical element. The optical element includes a first substrate, a plurality of first lower electrodes, a plurality of second lower electrodes, a liquid crystal layer, a second substrate, a plurality of first upper electrodes, and a plurality of second upper electrodes. The first substrate has a first region and a second region. The plurality of first lower electrodes are located on the first region and extend along a column direction. The plurality of second lower electrodes are located on the second region and extend along a column direction. The liquid crystal layer is located on the plurality of first lower electrodes and the plurality of second lower electrodes. The second substrate is opposed to the first substrate through the liquid crystal layer and has a third region and a fourth region that overlap with the first region and the second region, respectively. The plurality of first upper electrodes are located below the third region and extend along a row direction. The plurality of second upper electrodes are located below the fourth region and extend along a row direction. The plurality of first lower electrodes, the plurality of second lower electrodes, the plurality of first upper electrodes, and the plurality of second upper electrodes are driven independently of each other. Attached Figure Description

[0013] Figure 1 This is a schematic perspective view of a lighting device according to an embodiment of the present invention.

[0014] Figure 2 This is a schematic end view of the light source of the lighting device according to an embodiment of the present invention.

[0015] Figure 3A This is a schematic perspective view of the light source of the lighting device according to an embodiment of the present invention.

[0016] Figure 3B This is a schematic end view of the light source of the lighting device according to an embodiment of the present invention.

[0017] Figure 4 This is a schematic unfolded perspective view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0018] Figure 5 This is a schematic top view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0019] Figure 6A This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0020] Figure 6B This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0021] Figure 7A This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0022] Figure 7BThis is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0023] Figure 8 This is a schematic top view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0024] Figure 9A This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0025] Figure 9B This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0026] Figure 10A This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0027] Figure 10B This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0028] Figure 11 This is a schematic end view of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0029] Figure 12A This is a schematic end view illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0030] Figure 12B This is a schematic end view illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0031] Figure 13A This is a schematic end view illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0032] Figure 13B This is a schematic end view illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0033] Figure 14 This is a schematic diagram illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0034] Figure 15A This is a schematic top view illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0035] Figure 15BThis is a schematic top view illustrating the operating principle of the liquid crystal unit of the lighting device according to an embodiment of the present invention.

[0036] Figure 16 This is a schematic diagram showing the illumination area of ​​the lighting device according to an embodiment of the present invention.

[0037] Figure 17A This is a timing diagram of a lighting device according to an embodiment of the present invention.

[0038] Figure 17B This is a schematic diagram showing the illumination area of ​​the lighting device according to an embodiment of the present invention.

[0039] Figure 18A This is a timing diagram of a lighting device according to an embodiment of the present invention.

[0040] Figure 18B This is a schematic diagram showing the illumination area of ​​the lighting device according to an embodiment of the present invention.

[0041] Figure 19A This is a timing diagram of a lighting device according to an embodiment of the present invention.

[0042] Figure 19B This is a schematic diagram showing the illumination area of ​​the lighting device according to an embodiment of the present invention.

[0043] Figure 20A This is a timing diagram of a lighting device according to an embodiment of the present invention.

[0044] Figure 20B This is a schematic diagram showing the illumination area of ​​the lighting device according to an embodiment of the present invention.

[0045] Figure 21 This is a schematic perspective view of a lighting device according to an embodiment of the present invention.

[0046] Figure 22A This is a schematic top view of the light source of the lighting device according to an embodiment of the present invention.

[0047] Figure 22B This is a schematic top view of the light source of the lighting device according to an embodiment of the present invention.

[0048] Figure 23 This is a schematic perspective view of a lighting device according to an embodiment of the present invention.

[0049] Figure 24A This is a schematic top view of a lighting device according to an embodiment of the present invention.

[0050] Figure 24B This is a schematic top view of a lighting device according to an embodiment of the present invention.

[0051] Figure 25 This is a schematic unfolded perspective view of a lighting device according to an embodiment of the present invention. Detailed Implementation

[0052] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention can be implemented in various ways without departing from its spirit and is not limited to the description of the embodiments illustrated below.

[0053] In the accompanying drawings, to make the illustration clearer, the width, thickness, shape, etc., of various parts are sometimes shown schematically compared to the actual form, but these are merely examples and not intended to limit the interpretation of the invention. In this specification and the drawings, elements that have the same function as those already illustrated are sometimes labeled with the same reference numerals, omitting repeated descriptions. These reference numerals are used to generally represent multiple identical or similar structures; when these structures are represented individually, a hyphen and a natural number are added after the reference numerals. Furthermore, when representing a part of a structure, a lowercase letter is sometimes appended after the reference numeral.

[0054] In this specification and claims, when describing the manner in which other structures are arranged on top of a certain structure, the phrase "on top of" is used, unless otherwise specified, to include the following two situations: the situation in which other structures are arranged directly above a certain structure in contact with it, and the situation in which other structures are arranged above a certain structure, further separated by other structures.

[0055] In this specification and claims, the expression "orthogonal" for two structures includes not only the state in which the two structures intersect perpendicularly (90°), but also the state in which they intersect at an angle of 90° ± 10°.

[0056] In this specification and claims, the phrase "a structure is exposed from other structures" means that a portion of a structure is not covered by other structures, and also includes the possibility that the portion not covered by other structures is further covered by other structures. Furthermore, the manner indicated in this phrase also includes a structure not in contact with other structures.

[0057] <First Embodiment>

[0058] In this embodiment, an optical element according to one embodiment of the present invention, an illumination device 100 having the optical element, and a driving method thereof will be described.

[0059] 1. Overall structure of the lighting device

[0060] Figure 1 A schematic perspective view of the lighting device 100 is shown. Figure 1 As shown, the lighting device 100, as a basic structure, has a light source 110 and two optical elements that overlap with and are disposed on the light source 110. One optical element is a first liquid crystal cell 120-1 on the light source 110, and the other is a second liquid crystal cell 120-2 that overlaps with and is disposed on the first liquid crystal cell 120-1. The first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 can also be in direct contact, or they can be fixed to each other via an adhesive layer (not shown).

[0061] 1-1. Light source

[0062] The light source 110 has the following functions: supporting the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2, and generating light within the beam that is parallel (also called collimated light) or has low diffraction (strong straightness), and projecting it upwards. This light is supplied to the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2. Therefore, for example, along... Figure 1 A schematic diagram of the end face of the light source 110 with a single-dot dashed line AA′. Figure 2 As shown, the light source 110 may include a housing 112, one or more light-emitting elements 114 disposed within the housing 112, and one or more lenses 116 for converging light from the light-emitting elements 114.

[0063] The housing 112 may be made of metal, plastic, or wood, and its internal surface may be configured to have a high reflectivity relative to visible light. For example, a film containing metals such as aluminum, silver, gold, chromium, or stainless steel, a thin film containing highly flexible materials such as titanium oxide or tantalum oxide, or a laminate containing thin films containing low refractive index materials such as silicon oxide or magnesium fluoride may be disposed on the internal surface of the housing 112. The shape, thickness, and size of the housing 112 are arbitrary and may be appropriately set according to the performance sought by the lighting device 100 (size of the illumination area, optical characteristics of the lens 116, etc.).

[0064] The lens 116 can be configured to overlap with one or more light-emitting elements 114, and its optical characteristics can be appropriately set according to the degree of light diffusion from the light-emitting element 114, the distance from the light-emitting element 114, etc.

[0065] Or, it can be like Figure 3A and along Figure 3A A schematic diagram of the end face of the single-dash line BB′. Figure 3BAs shown, an inclined surface 112a is provided inside the housing 112 in such a way that light from one or more light-emitting elements 114 is reflected on the inner surface of the housing 112 to provide collimated light or light with low diffusion. In this case, a lens 116 for converging light may also be provided.

[0066] The light-emitting element 114 is a component that emits light by supplying current, and its construction is not restricted. A typical example is a light-emitting diode (LED). A light-emitting diode has a basic structure consisting of an electroluminescent element, such as gallium nitride or gallium nitride containing indium, sandwiched between a pair of electrodes, and a protective film protecting the electroluminescent element, and is configured to emit visible light through electroluminescence.

[0067] The color of light emitted by the light-emitting element 114 can also be arbitrarily selected. For example, the light-emitting element 114 that emits white light can be disposed in one or more housings 112, or the light source 110 can be configured in such a way that red light-emitting elements 114, green light-emitting elements 114, and blue light-emitting elements 114 are provided, and the light from these light-emitting elements 114 is mixed to obtain light emitted in various colors including white.

[0068] There are no restrictions on the size of each light-emitting element 114; for example, each element can occupy an area of ​​1.0 × 10⁻⁶. 4 μm 2 Above and 1.0×10 6 μm 2 Below, 4.0×10 4 μm 2 Above and 5.0×10 5 μm 2 Below or 9.0×10 4 μm 2 Above and 2.5×10 5 μm 2 The following are examples of light-emitting diodes. As an example, a so-called miniature LED with a size of approximately 320μm × 300μm can be used as the light-emitting element 114.

[0069] 1-2. Liquid Crystal Unit

[0070] As described above, in the lighting device 100, at least two liquid crystal units 120 are disposed on the light source 110. Figure 4 A schematic unfolded perspective view of two liquid crystal cells 120 is shown. The two liquid crystal cells 120 may have the same or different structures. Figure 4As shown, each liquid crystal cell 120 includes a first substrate 122 and a second substrate 130 opposite to the first substrate 122, and various elements constituting a liquid crystal element (a plurality of first lower electrodes 136, a plurality of second lower electrodes 138, a plurality of first upper electrodes 140, a plurality of second upper electrodes 142, a liquid crystal layer 154, a first alignment film 150, a second alignment film 152, etc.) are arranged between them.

[0071] (1) First substrate and second substrate

[0072] The first substrate 122 and the second substrate 130 function as substrates to provide mechanical strength to the liquid crystal cell 120 and provide a space for sealing the liquid crystal layer 154. The first substrate 122 and the second substrate 130 allow light from the light source 110 to pass through, thus exhibiting an illumination function; therefore, it is preferable to include materials that exhibit high transmittance relative to light from the light-emitting element 114. Therefore, it is preferable to construct the first substrate 122 and the second substrate 130, for example, using polymer materials such as glass, quartz, or polyimide, polycarbonate, polyester, or acrylic resin.

[0073] like Figure 5 As schematically shown, in each of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2, the first substrate 122 can be divided into multiple regions. Similarly, as... Figure 8 As shown, in each of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2, the second substrate 130 can also be divided into multiple regions. The number of regions in the first substrate 122 and the second substrate 130 is not limited; for example, it can be 2 or more but less than 20, 2 or more but less than 10, or 2 or more but less than 5. Furthermore, the shape of each region can be arbitrarily set. Figure 5 and Figure 8In the example shown, a cloud-shaped region and a region surrounding it are formed. Preferably, the first substrate 122 and the second substrate 130 each have the same number of regions, and each region has the same shape, size, and arrangement between the first substrate 122 and the second substrate 130. In this case, multiple regions of the first substrate 122 overlap with corresponding regions of the second substrate 130. Hereinafter, an example is used where the first substrate 122 has two regions (first region 124 and second region 126), and the second substrate 130 also has two regions (third region 132 and fourth region 134). The first region 124 and the third region 132 have the same shape and overlap each other entirely. Similarly, the second region 126 and the fourth region 134 also have the same shape and overlap each other entirely. Furthermore, the main surface of the first substrate 122 and the second substrate 130 is the xy plane. For convenience, the x-direction is called the row direction, and the y-direction, which is orthogonal to the x-direction, is called the column direction. The normal direction of the xy plane is taken as the z-direction. For example, the x and y directions are parallel to the edges of the first substrate 122 or the second substrate 130.

[0074] (2) Lower electrode and upper electrode

[0075] like Figure 5 As shown, each liquid crystal cell 120 has a plurality of first lower electrodes 136 and a plurality of second lower electrodes 138 arranged in a stripe pattern on a first substrate 122. The plurality of first lower electrodes 136 are disposed in a first region 124, and the plurality of second lower electrodes 138 are disposed in a second region 126. In other words, in the xy plane, a separate region selectively surrounding all of the plurality of first lower electrodes 136 is the first region 124, and a separate region selectively surrounding the plurality of second lower electrodes 138 is the second region 126. Figure 5 As shown, region 124 can also be surrounded by region 126, although not shown, region 126 can also be surrounded by region 124. Alternatively, region 124 and region 126 can be configured such that one region does not completely surround the other.

[0076] The plurality of first lower electrodes 136 and the plurality of second lower electrodes 138 are all along one direction, namely the column direction. Figure 5In the example shown, the first lower electrode 136 extends in the y-direction. In each column, either a single first lower electrode 136 may be configured, or multiple first lower electrodes 136 may overlap in the y-direction. Similarly, in each column, either a single second lower electrode 138 may be configured, or multiple second lower electrodes 138 may overlap in the y-direction. Furthermore, when the first region 124 overlaps with the second region 126 in the y-direction, one or more first lower electrodes 136 may be sandwiched between two adjacent second lower electrodes 138 in the y-direction.

[0077] Similarly, as Figure 8 As shown, each liquid crystal cell 120 has a plurality of first upper electrodes 140 and a plurality of second upper electrodes 142 arranged in a stripe pattern on the second substrate 130. The plurality of first upper electrodes 140 are disposed in a third region 132, and the plurality of second upper electrodes 142 are disposed in a fourth region 134. In other words, in the xy plane, a separate region selectively surrounding all of the plurality of first upper electrodes 140 is the third region 132, and a separate region selectively surrounding the plurality of second upper electrodes 142 is the fourth region 134. Figure 8 As shown, region 132 can also be surrounded by region 134, although not shown. Alternatively, region 132 and region 134 can be configured such that one region does not completely surround the other.

[0078] Furthermore, in this embodiment, a plurality of first lower electrodes 136 and second lower electrodes 138 extend in a stripe pattern along the column direction (y-direction), and a plurality of first upper electrodes 140 and second upper electrodes 142 extend along the row direction (x-direction). While each electrode extends as a whole along either the row or column direction, a single portion may also have a structure with slight bends at multiple locations. Additionally, the extension direction of each of the first lower electrodes 136 and second lower electrodes may also have an angle of approximately 1 to 10° relative to the y-direction. Similarly, the extension direction of each of the first upper electrodes 140 and second upper electrodes 142 may also have an angle of approximately 1 to 10° relative to the x-direction.

[0079] The plurality of first upper electrodes 140 and the plurality of second upper electrodes 142 are all along one direction, namely the travel direction. Figure 8In the example shown, the first upper electrode 140 extends in the x-direction. In each row, either a single first upper electrode 140 may be configured, or multiple first upper electrodes 140 may overlap in the x-direction. Similarly, in each row, either a single second upper electrode 142 may be configured, or multiple second upper electrodes 142 may overlap in the x-direction. Furthermore, when the third region 132 overlaps with the fourth region 134 in the x-direction, one or more first upper electrodes 140 may be sandwiched between two adjacent second upper electrodes 142 in the x-direction.

[0080] Although not shown in the figure, the plurality of first lower electrodes 136 and the plurality of second lower electrodes 138 may also be configured to extend along the row direction. In this case, the plurality of first upper electrodes 140 and the plurality of second upper electrodes 142 extend along the column direction.

[0081] Although details will be described later, light incident from the light source 110 passes through the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 and is emitted from the illumination device 100. Therefore, in order to impart high light transmittance to the liquid crystal cell 120, it is preferable that the first lower electrode 136, the second lower electrode 138, the first upper electrode 140, and the second upper electrode 142 are all formed of conductive oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO), which exhibit high transmittance relative to visible light.

[0082] A constant voltage or a pulsed AC voltage is applied to the first lower electrode 136, the second lower electrode 138, the first upper electrode 140, and the second upper electrode 142. In the case of AC voltage, the multiple first lower electrodes 136 are applied in a manner that reverses the phase between adjacent first lower electrodes 136 in the row direction. The same applies to the other electrodes. That is, the multiple second lower electrodes 138 are applied in a manner that reverses the phase between adjacent second lower electrodes 138 in the row direction, the multiple first upper electrodes 140 are applied in a manner that reverses the phase between adjacent first upper electrodes 140 in the column direction, and the multiple second upper electrodes 142 are applied in a manner that reverses the phase between adjacent second upper electrodes 142 in the column direction. Furthermore, the multiple first lower electrodes 136 that overlap in the column direction are applied with AC voltages that are in phase with each other, and the multiple second lower electrodes 138 that overlap in the column direction are also applied with AC voltages that are in phase with each other. Similarly, AC voltages of the same phase are applied to the plurality of first upper electrodes 140 that overlap in the row direction, and AC voltages of the same phase are also applied to the plurality of second upper electrodes 142 that overlap in the row direction.

[0083] In each liquid crystal cell 120, the first lower electrode 136, the second lower electrode 138, the first upper electrode 140, and the second upper electrode 142 can be driven by each region (region driving). Specifically, the first lower electrode 136 and the second lower electrode 138 can be driven independently of each other. Therefore, for example, it is possible to simultaneously apply the same or different AC voltages to the plurality of first lower electrodes 136 and the plurality of second lower electrodes 138, or it is possible to make one of the plurality of first lower electrodes 136 and the plurality of second lower electrodes 138 inactive (i.e., not applied voltage or applied constant voltage), and apply an AC voltage to the other. Similarly, the first upper electrode 140 and the second upper electrode 142 can also be driven independently of each other. Therefore, for example, it is possible to simultaneously apply the same or different AC voltages to the plurality of first upper electrodes 140 and the plurality of second upper electrodes 142, and it is also possible to make one of the plurality of first upper electrodes 140 and the plurality of second upper electrodes 142 non-operational (i.e., not apply voltage, or apply constant voltage), and apply AC voltage to the other.

[0084] use Figures 6A to 10B An example of a wiring configuration used to implement the area-driven approach described above will be illustrated. Figures 6A to 7B They are along Figure 5 A schematic diagram of the end faces of the single-dotted dashed lines CC′, DD′, EE′, and FF′. Figures 9A to 10B They are along Figure 8 A schematic diagram of the end faces of the single-dot dashed lines GG′, HH′, JJ′, and KK′.

[0085] As from Figure 6A and Figure 6B As understood, signal lines (first signal line 164, second signal line 166, third signal line 168, and fourth signal line 170) for supplying constant voltage or alternating voltage to the first lower electrode 136 and the second lower electrode 138 are arranged along the edge of the first substrate 122. These signal lines are formed of metals such as aluminum, copper, tantalum, tungsten, titanium, and molybdenum, or alloys containing at least one of these metals, and are disposed on the first substrate 122 in contact with it or via a base film 146. The base film 146 may be formed of one or more films containing silicon-containing inorganic compounds such as silicon nitride and silicon oxide. An interlayer insulating film 148 is formed on these signal lines. The interlayer insulating film 148 may also be formed of one or more films containing silicon-containing inorganic compounds, or it may be formed using polymeric compounds such as epoxy resin, acrylic resin, polyimide, polyamide, and silicone resin.

[0086] In the row direction, every other selected first lower electrode 136 is electrically connected to the third signal line 168 via an opening formed in the interlayer insulating film 148. Figure 6A These first lower electrodes 136 can also be directly connected to the third signal line 168, or they can be connected as follows: Figure 6A As shown, the third signal line 168 is connected via wiring 172, which exists on a different layer than the third signal line 168. The third signal line 168 and wiring 172 may also overlap with the second lower electrode 138. On the other hand, the remaining first lower electrode 136 is electrically connected to the fourth signal line 170 via an opening formed in the interlayer insulating film 148. Figure 6B These first lower electrodes 136 can also be directly connected to the fourth signal line 170, or they can be connected as follows: Figure 6B As shown, it is connected to the fourth signal line 170 via wiring 174 located on a different layer than the fourth signal line 170. A constant voltage or a pulsed AC voltage with reversed phase is supplied to the third signal line 168 and the fourth signal line 170. Therefore, when AC voltage is supplied to the third signal line 168 and the fourth signal line 170, the AC voltages applied to the adjacent first lower electrodes 136 in the row direction are reversed phase.

[0087] In the row direction, every other second lower electrode 138 is selected and electrically connected to the first signal line 164 via an opening formed in the interlayer insulating film 148. Figure 6A These second lower electrodes 138 can be directly connected to the first signal line 164, or they can be connected to the first signal line 164 via wiring (not shown). On the other hand, the remaining second lower electrodes 138 are electrically connected to the second signal line 166 via an opening formed in the interlayer insulating film 148. Figure 6B These second lower electrodes 138 can be directly connected to the second signal line 166, or they can be connected to the second signal line 166 via wiring not shown. A constant voltage or a pulsed AC voltage with reversed phase is supplied to the first signal line 164 and the second signal line 166. Therefore, when AC voltage is supplied to the first signal line 164 and the second signal line 166, the AC voltages applied to adjacent second lower electrodes 138 in the row direction are reversed phase.

[0088] like Figure 7A and Figure 7BAs shown, wiring 172 and wiring 174 can also be configured to extend along the x-direction as a part. By adopting this structure, every other selected first lower electrode 136 in the row direction can be connected to the third signal line 168 via wiring 172, and the remaining first lower electrodes 136 can be connected to the fourth signal line 170 via wiring 174.

[0089] The same wiring configuration can also be used for the second substrate 130. Specifically, as from... Figure 9A and Figure 9B As understood, on the second substrate 130, signal lines (signal line 5 180, signal line 6 182, signal line 7 184, signal line 8 186) for supplying constant voltage or alternating voltage to the first upper electrode 140 and the second upper electrode 142 are arranged along the edge of the second substrate 130. These signal lines are also formed using materials that can be used in the first signal line 164 to the fourth signal line 170, and are disposed on the second substrate 130 in contact with the second substrate 130 or via the base film 176. Figures 9A to 10B (Below the second substrate 130). The base film 176 may also be formed of one or more films containing silicon-containing inorganic compounds. An interlayer insulating film 178 is formed on these signal lines. The interlayer insulating film 178 may also be formed using a material that can be used in the interlayer insulating film 148.

[0090] Every other first upper electrode 140 selected in the column direction is electrically connected to the seventh signal line 184 via an opening formed in the interlayer insulating film 178. Figure 9A These first upper electrodes 140 can also be directly connected to the seventh signal line 184, or they can be connected as follows: Figure 9A As shown, the 7th signal line 184 is connected via wiring 188, which exists on a different layer than the 7th signal line 184. The 7th signal line 184 and wiring 188 may also overlap with the second upper electrode 142. On the other hand, the remaining first upper electrode 140 is electrically connected to the 8th signal line 186 via an opening formed in the interlayer insulating film 178. Figure 9B These first upper electrodes 140 can also be directly connected to the eighth signal line 186, or they can be connected as follows: Figure 9B As shown, the 7th signal line 184 is connected to the 8th signal line 186 via wiring 190 located on a different layer than the 8th signal line 186. A constant voltage or a pulsed AC voltage with reversed phase is supplied to the 7th signal line 184 and the 8th signal line 186. Therefore, when AC voltage is supplied to the 7th signal line 184 and the 8th signal line 186, the AC voltages applied to the adjacent first upper electrodes 140 in the column direction are reversed phase.

[0091] Every other second upper electrode 142 selected in the column direction is electrically connected to the fifth signal line 180 via an opening formed in the interlayer insulating film 178. Figure 9A These second upper electrodes 142 can be directly connected to the fifth signal line 180, or they can be connected to the fifth signal line 180 via wiring (not shown). On the other hand, the remaining second upper electrodes 142 are electrically connected to the sixth signal line 182 via an opening formed in the interlayer insulating film 178. Figure 9B These second upper electrodes 142 can also be directly connected to the sixth signal line 182, or they can be connected to the sixth signal line 182 via wiring not shown. A constant voltage or a pulsed AC voltage with reversed phase is supplied to the fifth signal line 180 and the sixth signal line 182. Therefore, when an AC voltage is supplied to the fifth signal line 180 and the sixth signal line 182, the AC voltages supplied to adjacent second upper electrodes 142 in the column direction are reversed phase.

[0092] like Figure 10A , Figure 10B As shown, wiring 188 and wiring 190 can also be configured to extend along the x-direction as a part. By adopting this structure, every other selected second upper electrode 142 in the column direction can be connected to the seventh signal line 184 via wiring 188, and the remaining second upper electrode 142 can be connected to the eighth signal line 186 via wiring 190.

[0093] Although not shown in the figure, signal lines are further provided when the number of regions provided on the first substrate 122 and the second substrate 130 is 3 or more. Specifically, if the number of regions on the first substrate 122 and the second substrate 130 is set to n (n is a natural number of 2 or more), then 2n signal lines can be provided on each of the first substrate 122 and the second substrate 130. In addition, in this specification, signal lines with the same function are marked with the same reference numerals, and when signal lines given the same reference numerals are divided into multiple, these signal lines are also the same.

[0094] The widths (length of the x-direction intersecting the y-direction, which is the long side) of the first lower electrode 136 and the second lower electrode 138 are selected from, for example, a range of 2 μm or more and 10 μm or less. The distances between adjacent first lower electrodes 136, second lower electrodes 138, and the distance between the first lower electrode 136 and the second lower electrode 138 in the row direction are also selected from, for example, a range of 2 μm or more and 10 μm or less. As a typical example, the width of the first lower electrode 136 and the spacing in the row direction of the second lower electrode 138 can be 5 μm and 10 μm, respectively.

[0095] The same applies to the first upper electrode 140 and the second upper electrode 142. Their widths (the length of the y-direction intersecting the x-direction, which is the long side) are selected from, for example, a range of 2 μm or more and 10 μm or less. The distances between adjacent first upper electrodes 140 in the column direction, the distances between second upper electrodes 142, and the distances between the first upper electrode 140 and the second upper electrode 142 are also selected from, for example, a range of 2 μm or more and 10 μm or less. As a typical example, the width of the first upper electrode 140 and the spacing in the column direction of the second upper electrode 142 can be 5 μm and 10 μm, respectively.

[0096] (3) First alignment film, second alignment film and liquid crystal layer

[0097] A first alignment film 150 is disposed on a plurality of first lower electrodes 136 and a plurality of second lower electrodes 138. Figure 6A , Figure 6B ), on top of a plurality of first upper electrodes 140 and a plurality of second upper electrodes 142 ( Figures 9A to 10B A second alignment film 152 is disposed below multiple first upper electrodes 140 and multiple second upper electrodes 142. Figure 9A , Figure 9B The first substrate 122 and the second substrate 130 are bonded and fixed together by the sealing member 128. Figure 11 A liquid crystal layer 154 is filled in the space formed by the first substrate 122, the second substrate 130 and the sealing member 128.

[0098] The first alignment film 150 and the second alignment film 152 comprise polymers such as polyimide and polyester, and their surfaces are subjected to a rubbing treatment. For the rubbing treatment, the orientation direction of the first alignment film 150 intersects the directions in which the first lower electrode 136 and the second lower electrode 138 extend at a predetermined angle or perpendicularly (see reference). Figure 5 (See the arrow). Furthermore, the orientation direction of the second orientation film 152 intersects the directions in which the first upper electrode 140 and the second upper electrode 142 extend at a predetermined angle or perpendicularly (see reference). Figure 8 (The arrows indicate this). Therefore, the orientation direction of the first alignment film 150 intersects or is orthogonal to the orientation direction of the second alignment film 152 at a predetermined angle. Here, the orientation direction is the direction of the long axis of the liquid crystal molecules when they are aligned in a field-free state due to the influence of the alignment film. Alternatively, the light distribution control direction of the first alignment film 150 and the second alignment film 152 can be controlled by optical alignment instead of rubbing. Optical alignment is a frictionless alignment process using light, for example, irradiating an alignment film without rubbing with polarized light from a predetermined direction in the ultraviolet region. This generates a photoreaction in the alignment film, introducing anisotropy onto the surface of the alignment film and imparting liquid crystal alignment control energy.

[0099] The liquid crystal layer 154 contains liquid crystal molecules. The structure of the liquid crystal molecules is not limited. Therefore, the liquid crystal molecules can also be nematic liquid crystals, or smectic liquid crystals, cholesteric liquid crystals, or chiral smectic liquid crystals.

[0100] The thickness d of the liquid crystal layer 154 (refer to) Figure 11 The distance between the first alignment film 150 and the second alignment film 152 is arbitrary, but preferably greater than the spacing between the first lower electrode 136, the second lower electrode 138, the first upper electrode 140, and the second upper electrode 142. For example, the thickness d of the liquid crystal layer 154 is preferably set to be more than 2 times and less than 10 times, more than 2 times and less than 5 times, or more than 2 times and less than 3 times the spacing between these electrodes. Specifically, the thickness of the liquid crystal layer 154 can be selected from, for example, a range of 20 μm and more than 60 μm or 20 μm and more than 50 μm. Although not shown, a spacer for maintaining this thickness throughout the entire illumination device 100 can also be provided within the liquid crystal layer 154. In addition, when the above-described thickness of the liquid crystal layer 154 is used in a liquid crystal display device, the high liquid crystal responsiveness required for displaying animation cannot be obtained, making it difficult to demonstrate the function of a liquid crystal display device.

[0101] (4) Other structures

[0102] In each liquid crystal cell 120, a driving circuit 144 is provided on the first substrate 122 for generating a constant voltage or alternating voltage for illumination and supplying it from the first signal line 164 to the eighth signal line 186. Figure 4 The driving circuit 144 may be formed by appropriately combining various conductive films, semiconductor films, and conductive films patterned on the first substrate 122, or it may be formed by mounting an IC chip having an integrated circuit formed on a semiconductor substrate on the first substrate 122. Alternatively, the driving circuit 144 may not be provided on the first substrate 122, but the IC chip may be provided as the driving circuit 144 on a connector such as a flexible printed circuit board (FPC) connected to the first signal line 164 to the eighth signal line 186.

[0103] 2. Mechanism of Action

[0104] As described above, light emitted from the light-emitting element 114 passes through the first liquid crystal cell 120-1 and further through the second liquid crystal cell 120-2 before being emitted from the illumination device 100. Each liquid crystal cell 120 is provided with a plurality of first lower electrodes 136 and a plurality of second lower electrodes 138 arranged in a stripe pattern, a liquid crystal layer 154, and a plurality of first upper electrodes 140 and a plurality of second upper electrodes 142 arranged in a stripe pattern and intersecting the first lower electrodes 136 and second lower electrodes 138. Therefore, by controlling the voltage applied to these electrodes, the liquid crystal layer 154 can function as a liquid crystal lens. Furthermore, the electrodes disposed in the first region 124, the second region 126, the third region 132, and the fourth region 134 are controlled independently of each other. As a result, light passing through the first region 124 and the third region 132, and light passing through the second region 126 and the fourth region 134, can be diffused individually. Therefore, the illumination area of ​​the light extracted from the light source 110 via the two liquid crystal cells 120 can be controlled in a variety of ways and arbitrarily. Furthermore, patterns reflecting the shape of each region can be displayed in the illumination area. Hereinafter, the operating principle and driving method of the illumination device 100 will be explained. Here, "illumination area" refers to the area on the object that is illuminated when the illumination device 100 is driven. However, the illumination area varies depending on the angle between the direction of light travel and the surface on the object, and the distance between the illumination device 100 and the object. Therefore, "illumination area" is defined as the area on which light from the illumination device 100 is illuminated in a plane (illumination surface) perpendicular to the normal of the main surface of the second substrate 130 of the liquid crystal cell 120. In the following description, the operating principle of the overlapping part of the first region 124 and the third region 132 is the same as that of the overlapping part of the second region 126 and the fourth region 134. Therefore, the operating principle of the former will be explained.

[0105] 2-1. Non-driving time

[0106] Figure 12A and Figure 12B A schematic diagram showing the end face of the liquid crystal cell 120 when not driven. Figure 12A This is a diagram viewed from the row direction (x-direction). Figure 12B This is a schematic diagram viewed from the column direction (y-direction). Figure 12A and Figure 12B In the diagram, liquid crystal molecules are schematically depicted as ellipses.

[0107] As described above, the orientation directions of the first alignment film 150 and the second alignment film 152 are orthogonal to the directions in which the plurality of first lower electrodes 136 and the plurality of first upper electrodes 140 extend, respectively. Therefore, when the liquid crystal cell 120 is not driven, i.e., when no voltage is applied to the plurality of first lower electrodes 136 and the plurality of first upper electrodes 140, or when a constant voltage is applied to the plurality of first lower electrodes 136 and the plurality of first upper electrodes 140 respectively, the orientation of the liquid crystal molecules is determined by the orientation direction without being affected by the electric field. As a result, on the first lower electrode 136 side, the long axis of the liquid crystal molecules is oriented in a direction perpendicular to the direction (x-direction) in which the first lower electrode 136 extends. On the other hand, on the first upper electrode 140 side, the long axis of the liquid crystal molecules is oriented in a direction perpendicular to the direction (y-direction) in which the first upper electrode 140 extends. Furthermore, the orientation of the liquid crystal molecules rotates around the z-axis as they approach the second substrate 130 from the first substrate 122, twisting by 90°.

[0108] 2-2. During driving

[0109] During driving, a pulsed AC voltage is applied to the plurality of first lower electrodes 136 of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 in such a way that the phase is reversed between adjacent first lower electrodes 136 in the row direction. Similarly, a pulsed AC voltage is applied to the plurality of first upper electrodes 140 of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 in such a way that the phase is reversed between adjacent first upper electrodes 140 in the column direction. The frequency of the AC voltage is the same in each liquid crystal cell 120. The AC voltage can be selected from, for example, a range of 5V or higher and 50V or lower, or 5V or higher and 30V or lower. By applying the AC voltage, the phases between adjacent first lower electrodes 136 in the row direction and between adjacent first upper electrodes 140 in the column direction are respectively as follows: Figure 13A and Figure 13B The arrow indicates the generation of an electric field (lateral electric field). On the other hand, an electric field (vertical electric field) is also generated between the first lower electrode 136 and the first upper electrode 140, but as described above, the thickness d of the liquid crystal layer 154 is greater than the distance between adjacent first lower electrodes 136 and first upper electrodes 140. Therefore, the vertical electric field is negligible relative to the lateral electric field, and the liquid crystal molecules are oriented according to the lateral electric field.

[0110] If a lateral electric field is generated within the liquid crystal layer 154, the liquid crystal molecules located almost in the middle between adjacent first lower electrodes 136 on the first substrate 122 side maintain their initial orientation because the direction of the lateral electric field is almost parallel to the upper surface of the first substrate 122. However, as the electric field direction tilts towards the z-direction closer to the first upper electrode 140, the liquid crystal molecules also tilt towards the z-direction, and the angle (tilt angle) increases. As a result, the liquid crystal molecules in the liquid crystal layer on the first substrate 122 side are oriented in an upwardly convex arc shape. Figure 13A Similarly, on the second substrate 130 side, the liquid crystal molecules located almost in the middle between adjacent first upper electrodes 140 maintain their initial orientation because the direction of the lateral electric field is almost parallel to the lower surface of the second substrate 130. However, as they approach the first upper electrode 140, the electric field direction tilts towards the z-direction, and therefore, the liquid crystal molecules also tilt towards the z-direction, with an increased tilt angle. As a result, the liquid crystal molecules in the liquid crystal layer on the second substrate 130 side are oriented in a downwardly convex arc shape. Figure 13B ).

[0111] By altering the orientation of the liquid crystal molecules, light incident on the liquid crystal layer 154 is diffused according to the refractive index distribution of the liquid crystal molecules oriented in an arc shape on the first substrate 122 side, and further diffused according to the refractive index distribution of the liquid crystal molecules oriented in an arc shape on the second substrate 130 side. As a result, the liquid crystal cell 120 functions as a lens for light diffusion. Figure 14 The diffusion mechanism of this light is explained in detail. Figure 14 Showing the representation Figure 13A and Figure 13B The diagram shows a schematic perspective view of the orientation of the liquid crystal molecules and a schematic diagram illustrating the behavior of light transmitted through the two liquid crystal cells 120. Here, the following example is used as a model for illustration: between the two liquid crystal cells 120, the directions in which the first lower electrode 136 extends are parallel to each other, and the directions in which the first upper electrode 140 extends are also parallel to each other.

[0112] If, as described above, a pulsed alternating voltage is applied to the plurality of first lower electrodes 136 in such a way that the phases of adjacent first lower electrodes 136 are reversed, and a pulsed alternating voltage is applied to the plurality of first upper electrodes 140 in such a way that the phases of adjacent first upper electrodes 140 are reversed, then as Figure 14As shown, a transverse electric field is generated that is orthogonal to the first lower electrode 136 side and the first upper electrode 140 side. As a result, the liquid crystal molecules in the liquid crystal layer are oriented upwards between the adjacent first lower electrode 136 sides on the first substrate 122 side and downwards between the adjacent first upper electrode 140 sides on the second substrate 130 side. Furthermore, the orientation of the liquid crystal molecules is twisted by 90° from the first lower electrode 136 towards the first upper electrode 140.

[0113] like Figure 14 As shown, light emitted from light source 110 initially enters the first liquid crystal cell 120-1. This light has a polarized light component 200 in the y-direction (straight arrow in the figure) and a polarized light component 206 in the x-direction (symbol with a cross inside the circle in the figure). Hereinafter, for convenience, the polarized light component 200 in the y-direction of the light before it enters the liquid crystal cell 120 will be referred to as the S-component, and the polarized light component 206 in the x-direction will be referred to as the P-component, using these names regardless of the rotation of the polarization axis.

[0114] On the side of the first lower electrode 136, the liquid crystal molecules are oriented along the y-direction, therefore, the liquid crystal layer 154 has a refractive index distribution in the y-direction. Thus, the S-component 200 incident on the liquid crystal layer 154 diffuses in the y-direction according to the refractive index distribution on the side of the first lower electrode 136. When this light passes through the liquid crystal layer 154, it rotates due to the twisting of the orientation of the liquid crystal molecules, changing its polarization axis to the x-direction. Thus, on the side of the first upper electrode 140, the liquid crystal layer 154 has a refractive index distribution in the x-direction, therefore, the light further diffuses in the x-direction. As a result, if the S-component 200 passes through the liquid crystal layer 154 of the first liquid crystal cell 120-1, it becomes the S-component 202 diffused in both the x and y directions.

[0115] On the other hand, the P component 206 incident on the first liquid crystal cell 120-1 has a refractive index distribution in the y-direction on the side of the first lower electrode 136. Therefore, it is not affected by the refractive index distribution and rotates light through the twisting of the orientation of the liquid crystal molecules without diffusion, with the polarization axis changing to the y-direction. Furthermore, the refractive index distribution on the side of the first upper electrode 140 is in the x-direction. Therefore, the P component 206 with the polarization axis changing to the y-direction is not affected by the refractive index distribution. As a result, if the P component 206 passes through the liquid crystal layer 154 of the first liquid crystal cell 120-1, it becomes a non-diffused and optically rotating P component 208.

[0116] Next, consider the light passing through the first liquid crystal cell 120-1. As described above, in this model, the long sides of the first lower electrode 136 between the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 are parallel to each other, and the long sides of the first upper electrode 140 are also parallel to each other. Therefore, in the liquid crystal layer 154 of the second liquid crystal cell 120-2, there is a refractive index distribution in the y-direction on the side of the first lower electrode 136, and a refractive index distribution in the x-direction on the side of the first upper electrode 140.

[0117] As described above, S component 200 becomes S component 202 diffused in both the x and y directions when passing through the first liquid crystal cell 120-1. Since the polarization axis of this S component 202 is orthogonal to the direction of the refractive index distribution on the side of the first lower electrode 136 of the second liquid crystal cell 120-2, it does not diffuse. During its passage through the liquid crystal layer 154, S component 202 rotates due to the twisting of the liquid crystal molecules' orientation, changing its polarization axis to the y direction. However, the refractive index distribution on the side of the first upper electrode 140 is in the x direction, and therefore it is not affected by the refractive index distribution. As a result, although S component 202 rotates through the second liquid crystal cell 120-2, it does not diffuse and becomes S component 204. In summary, the S component 200 emitted from the light source 110 diffuses and rotates in the x and y directions through the first liquid crystal cell 120-1 to become the S component 202, and does not diffuse but rotates in the second liquid crystal cell 120-2, ultimately becoming the S component 204 diffused in the x and y directions.

[0118] On the other hand, the P component 208 incident on the liquid crystal layer 154 of the second liquid crystal cell 120-2 diffuses in the y-direction according to the refractive index distribution in the y-direction on the side of the first lower electrode 136. When the light passes through the liquid crystal layer 154, it rotates due to the twisting of the orientation of the liquid crystal molecules, and the polarization axis becomes the x-direction. Thus, on the side of the first upper electrode 140, the liquid crystal layer 154 has a refractive index distribution in the x-direction, so the light diffuses in the x-direction. As a result, if the P component 208 passes through the second liquid crystal cell 120-2, it becomes the P component 210, which is optically rotated and diffused in both the x and y directions. In summary, the P component 206 emitted from the light source 110 rotates without diffusion when passing through the first liquid crystal cell 120-1, rotates when passing through the second liquid crystal cell 120-2 and diffuses in both the x and y directions, and finally becomes the P component 210, which is diffused in both the x and y directions.

[0119] The degree of orientation of the liquid crystal molecules can be controlled by applying voltages to the first lower electrode 136 and the first upper electrode 140, respectively. Therefore, the degree of light diffusion can also be controlled by applying voltages to the first lower electrode 136 and the first upper electrode 140. Thus, according to the above mechanism, the degree of light diffusion passing through the first region 124 and the third region 132 can be independently controlled by applying voltages to the first lower electrode 136 and the first upper electrode 140.

[0120] Furthermore, light diffusion is controlled by the lateral electric field generated between adjacent first lower electrodes 136 and adjacent first upper electrodes 140. Therefore, for light diffusion, a potential difference is applied between adjacent first lower electrodes 136 and / or adjacent first upper electrodes 140 in each liquid crystal cell. Thus, a constant voltage with different voltages can be applied to adjacent first lower electrodes 136, or an AC voltage can be applied to every other selected plurality of first lower electrodes 136, while a constant voltage is applied to the remaining first lower electrodes 136. The same applies to the first upper electrode 140.

[0121] 3. Light distribution control

[0122] By utilizing the mechanism described above, the irradiation area from the light source 110 can be arbitrarily controlled, and a pattern reflecting the shape of the first region 124 to the fourth region 134 can be displayed on the irradiated surface. This will be explained below.

[0123] In the following explanation, such as Figure 15A As shown, in each liquid crystal cell 120, an AC voltage V is applied to every other selected plurality of first lower electrodes 136. 136-1 An AC voltage V is applied to the remaining plurality of first lower electrodes 136. 136-2 An alternating voltage V is applied to every other selected plurality of second lower electrodes 138. 138-1 An AC voltage V is applied to the remaining multiple second lower electrodes 138. 138-2 Similarly, as Figure 15B As shown, an AC voltage V is applied to every other selected plurality of first upper electrodes 140. 140-1 An AC voltage V is applied to the remaining plurality of first upper electrodes 140. 140-2 An alternating voltage V is applied to every other selected plurality of second upper electrodes 142. 142-1 An AC voltage V is applied to the remaining multiple second upper electrodes 142. 142-2In this model, between the two liquid crystal cells 120, the first lower electrode 136, the second lower electrode 138, the first upper electrode 140, and the second upper electrode 142 are also parallel to each other. As described above, the shape of the regions formed in each liquid crystal cell 120 is arbitrary. Therefore, in a part of the following description, the following example is used: the first region 124 and the third region 132 have the same star shape, and the second region 126 and the fourth region 134 have a shape that surrounds the aforementioned star shape.

[0124] 3-1. When the liquid crystal cell is not driven

[0125] When the liquid crystal cell 120 is not driven, no electric field is generated between adjacent electrodes. Therefore, the liquid crystal layer 154 lacks a refractive index distribution; thus, although the S component 200 and P component 206 rotate through each liquid crystal cell 120, they do not exhibit a diffusion effect. Therefore, for example... Figure 16 As shown, the light emitted from the light source 110 does not expand significantly even after passing through the two liquid crystal cells 120, and provides a relatively narrow illumination area 102-1 on the illumination surface 104 such as the floor.

[0126] 3-2. Driving the LCD cell

[0127] As an example, consider the following: Figure 17A The timing diagram shows the driving state of the liquid crystal cell 120. Here, in each liquid crystal cell 120, an AC voltage is applied to the plurality of first lower electrodes 136 in a manner that reverses the phase between adjacent first lower electrodes 136, and an AC voltage is applied to the plurality of second lower electrodes 138 in a manner that reverses the phase between adjacent second lower electrodes 138. Similarly, in each liquid crystal cell 120, an AC voltage is applied to the plurality of first upper electrodes 140 in a manner that reverses the phase between adjacent first upper electrodes 140, and an AC voltage is applied to the plurality of second upper electrodes 142 in a manner that reverses the phase between adjacent second upper electrodes 142. The applied voltages are the same.

[0128] If the liquid crystal cell 120 is operated in this way, then as from Figure 14 As understood, the S component 200 and P component 206 of the light from the light source 110 pass through the two liquid crystal cells 120, thereby diffusing in the x and y directions. Therefore, for the illumination device 100, compared to the illumination area 102-1 formed without driving the two liquid crystal cells 120, an illumination area 102-2 that is expanded in the x and y directions is provided. Figure 17BFurthermore, since the applied voltages are the same for all regions, the light passing through regions 124 and 332 diffuses to approximately the same degree as the light passing through regions 226 and 434. Therefore, the shape of each region is not reflected, and the illuminance distribution in irradiated region 102-2 is small.

[0129] As another example, consider such Figure 18A The timing diagram shows the driving conditions of the liquid crystal cell 120. Here, in each liquid crystal cell 120, an AC voltage is applied relative to the first lower electrode 136 in such a way that the phase is reversed between adjacent first lower electrodes 136, and an AC voltage is applied relative to the plurality of second lower electrodes 138 in such a way that the phase is reversed between adjacent second lower electrodes 138. On the other hand, in each liquid crystal cell 120, no voltage is applied or a constant voltage (e.g., ground voltage) is applied relative to the plurality of first upper electrodes 140 and the plurality of second upper electrodes 142.

[0130] In this case, no lateral electric field is generated on the second substrate 130 side of the liquid crystal layer 154 of each liquid crystal cell 120, and therefore, no refractive index distribution is generated. Therefore, as from... Figure 14 As understood, both S component 200 and P component 206 diffuse only in the x-direction. As a result, as... Figure 18B As schematically shown, an irradiation area 102-3, which is expanded in one direction (x-direction) compared to the irradiation area 102-1, is provided. Although detailed descriptions are omitted, by applying no voltage or a constant voltage (e.g., ground voltage) to the plurality of first lower electrodes 136 and the plurality of second lower electrodes 138, and by applying an AC voltage to the plurality of first upper electrodes 140 in a manner that reverses the phase between adjacent first upper electrodes 140, and by applying an AC voltage to the plurality of second upper electrodes 142 in a manner that reverses the phase between adjacent second upper electrodes 142, an irradiation area expanded in the y-direction can also be obtained. Furthermore, the degree of expansion can be controlled by the voltage of the AC voltage.

[0131] As another example, consider such Figure 19A The timing diagram shows the driving state of the liquid crystal cell 120. Here, in each liquid crystal cell 120, an AC voltage is applied to the plurality of second lower electrodes 138 in such a way that the phase is reversed between adjacent second lower electrodes 138, and an AC voltage is applied to the plurality of second upper electrodes 142 in such a way that the phase is reversed between adjacent second upper electrodes 142. On the other hand, in each liquid crystal cell 120, no voltage is applied or a constant voltage is applied to the plurality of first lower electrodes 136 and the plurality of first upper electrodes 140.

[0132] In this driving process, the light passing through the first region 124 and the third region 132 does not diffuse. The collimated light emitted from the light source 110 does not expand significantly, but instead forms a relatively high illuminance illumination region 102-4 in the illumination surface 104.

[0133] On the other hand, light passing through the second region 126 and the fourth region 134 diffuses according to the refractive index distributions formed on the first substrate 122 and the second substrate 130 sides of the liquid crystal layer 154, respectively. Therefore, although a larger irradiation area 102-5 is provided, the illuminance of the irradiation area 102-5 is lower than that of the irradiation area 102-4 due to the enlargement of the irradiation area. As a result, a pattern reflecting the shape of the first region 124 to the fourth region 134 can be displayed on the irradiation surface 104 using the difference in illuminance. Figure 19B ).

[0134] As a contrasting example, consider... Figure 20A The timing diagram shows the driving state of the liquid crystal cell 120. Here, in each liquid crystal cell 120, an AC voltage is applied to the plurality of first lower electrodes 136 in such a way that the phase is reversed between adjacent first lower electrodes 136, and an AC voltage is applied to the plurality of first upper electrodes 140 in such a way that the phase is reversed between adjacent first upper electrodes 140. On the other hand, in each liquid crystal cell 120, no voltage is applied or a constant voltage is applied to the plurality of second lower electrodes 138 and the plurality of second upper electrodes 142.

[0135] In this driving process, the light passing through the second region 126 and the fourth region 134 does not diffuse. That is, the light emitted from the second region 126 and the fourth region 134 does not expand significantly, but instead forms a relatively high illuminance ...

[0136] On the other hand, light passing through the first region 124 and the third region 132 diffuses according to the refractive index distributions formed on the first substrate 122 and the second substrate 130 sides of the liquid crystal layer 154, respectively. Therefore, a larger irradiation region 102-7 is provided compared to the irradiation region 102-4, but the illuminance of this irradiation region 102-7 is lower than that of the irradiation region 102-6. As a result, a pattern reflecting the shape of the first region 124 to the fourth region 134 can be displayed on the irradiation surface 104 using the difference in illuminance. Figure 20B ).

[0137] like Figure 21As shown, when a light-transmitting cover 108 is provided on the liquid crystal unit 120 of the lighting device 100, the cover 108 also becomes the illumination surface 104. Therefore, a pattern reflecting the shape of the first region 124 to the fourth region 134 can be displayed on the cover 108. Thus, the light source 110 displaying various patterns can also be viewed.

[0138] Thus, by applying the embodiments of the present invention, the light from the light source 110 can be arbitrarily distributed to create illumination areas of various shapes, and patterns reflecting the shapes of each area can be displayed on the illumination surface. In this lighting device 100, the polarizing plate used in liquid crystal projectors and liquid crystal display devices is not required. Furthermore, in the display of light patterns, there is no need to physically block the light from the light source 110. Therefore, the light from the light source 110 can be effectively utilized. As a result, light patterns can be displayed without increasing power consumption.

[0139] <Second Implementation>

[0140] In this embodiment, a variation of the lighting device 100 described in the first embodiment will be described. Sometimes, descriptions of structures that are the same as or similar to those described in the first embodiment are omitted.

[0141] 1. Variation Example 1

[0142] As described in the first embodiment, the number of regions disposed on the first substrate 122 and the second substrate 130 is not limited. Therefore, in a modified example, it is also possible to... Figure 22A and Figure 22B As shown, a fifth region 220 and a sixth region 222 are provided on the first substrate 122, and a seventh region 224 and an eighth region 226, which overlap with the fifth region 220 and the sixth region 222, are provided on the second substrate 130. In this modified example, the fifth region 220 and the sixth region 222 are surrounded by the first region 124, and the seventh region 224 and the eighth region 226 are surrounded by the third region 132. If the first region 124 and the third region 132 are made non-driven, and the other regions are driven, the light passing through the first region 124 and the third region 132 travels in a straight line, providing a higher illumination area to the illumination surface 104. Therefore, it is also possible to display more complex graphics such as numbers.

[0143] 2. Variation Example 2

[0144] The lighting device 100 may also have multiple liquid crystal cells 120 on the second liquid crystal cell 120-2, in addition to the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2. The number of layers of liquid crystal cells 120 is not limited and can be 2 or more but less than 10, 2 or more but less than 6, or 2 or more but less than 4. Preferably, the total number of liquid crystal cells 120 is an even number. Figure 23 The image shows an example where the third liquid crystal unit 120-3 and the fourth liquid crystal unit 120-4 are mounted on the second liquid crystal unit 120-2.

[0145] When the total number of liquid crystal cells 120 exceeds two, the shapes of the regions divided on the first substrate 122 and the second substrate 130 of each of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 may differ from the shapes of the regions divided on the first substrate 122 and the second substrate 130 of the other liquid crystal cells 120. For example, it is also possible that the lighting device 100 has a third liquid crystal cell 120-3 and a fourth liquid crystal cell 120-4 in addition to the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2. Figure 23 In the first substrate 230 of the third liquid crystal cell 120-3, a ninth region 232 and a tenth region 234 with different shapes from the first region 124 and the second region 126 of the first liquid crystal cell 120-1 are provided. Figure 24A In the aforementioned 9th region 232 and 10th region 234, multiple first lower electrodes 236 and multiple second lower electrodes 238 can be selectively formed, respectively. Similarly, in the second substrate 240 of the third liquid crystal cell 120-3, 11th region 242 and 12th region 244 with different shapes from the first region 124 and second region 126 of the first liquid crystal cell 120-1 can be provided. The shapes of the 11th region 242 and 12th region 244 can also be the same as those of the 9th region 232 and 10th region 234, respectively. Multiple first upper electrodes 246 and multiple second upper electrodes 248 can be selectively arranged in the aforementioned 11th region 242 and 12th region 244, respectively. The same applies to the fourth liquid crystal cell 120-4, therefore, the description is omitted.

[0146] The first lower electrode 236 and the second lower electrode 238 correspond to the first lower electrode 136 and the second lower electrode 138 of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2, respectively. Therefore, the same driving method as that used for the first lower electrode 136 and the second lower electrode 138 can be applied. Similarly, the first upper electrode 246 and the second upper electrode 248 correspond to the first upper electrode 140 and the second upper electrode 142 of the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2, respectively. Therefore, the same driving method as that used for the first upper electrode 140 and the second upper electrode 142 can be applied. Detailed descriptions related to the driving method are omitted, but by appropriately driving the third liquid crystal cell 120-3 and the fourth liquid crystal cell 120-4, and more specifically by driving the third liquid crystal cell 120-3 and the fourth liquid crystal cell 120-4 while the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 are in a non-driven state, a pattern reflecting the shape of the 9th region 232 to the 12th region 244 can be displayed on the irradiated surface 104. Similarly, by driving the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 while the third liquid crystal cell 120-3 and the fourth liquid crystal cell 120-4 are in a non-driven state, a pattern reflecting the shape of the 1st region 124 to the 8th region 226 can be displayed on the irradiated surface.

[0147] In this way, the liquid crystal unit 120 is configured such that the patterns displayed by one pair of liquid crystal units (here, the first liquid crystal unit 120-1 and the second liquid crystal unit 120-2) are different from those displayed by another pair of liquid crystal units (here, the third liquid crystal unit 120-3 and the fourth liquid crystal unit 120-4), thereby enabling multiple patterns to be displayed on the irradiated surface 104.

[0148] 3. Variation Example 3

[0149] The lighting device 250 involved in this variation is as follows: Figure 25 As shown in the schematic unfolded view, the difference from the lighting device 100 described in the first embodiment is that, in at least one of the liquid crystal cells 120, a separate upper electrode 252 is provided on the second substrate 130, and this upper electrode 252 is configured to overlap with multiple regions provided on the first substrate 122. The upper electrode 252 overlaps with multiple first lower electrodes 136 and multiple second lower electrodes 138.

[0150] In the lighting device 250, the refractive index distribution of the liquid crystal layer 154 is generated only on the side of the first substrate 122. Therefore, as from... Figure 14As understood, light is diffused in both the x and y directions. Therefore, it is preferable to arrange the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 in such a way that the extension directions of the plurality of first lower electrodes 136 or the plurality of second lower electrodes 138 are different from each other between the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2.

[0151] Although not shown, a single lower electrode can be provided on the first substrate 122, and multiple first upper electrodes 140 and multiple second upper electrodes 142 can be provided on the second substrate 130 side. In this case, light is also diffused in both the x and y directions. Therefore, it is preferable to arrange the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 such that the extending directions of the multiple first upper electrodes 140 or the multiple second upper electrodes 142 are different from each other between the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2.

[0152] Although not shown, electrodes may not be disposed on the second substrate 130 side. In this case, multiple first lower electrodes 136 and multiple second lower electrodes 138 are disposed on the first substrate 122 in the first region 124 and the second region 126, respectively. The refractive index distribution of the liquid crystal layer 154 is generated only on the first substrate 122 side; therefore, as shown from... Figure 14 As understood, light is diffused in both the x and y directions. Therefore, it is preferable to arrange the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 in such a way that the extension directions of the plurality of first lower electrodes 136 or the plurality of second lower electrodes 138 are different from each other between the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2.

[0153] Alternatively, no electrodes may be disposed on the first substrate 122 side. In this case, a plurality of first upper electrodes 140 and a plurality of second upper electrodes 142 are disposed in the third region 132 and the fourth region 134 of the second substrate 130, respectively. In this case, light is also diffused in both the x and y directions. Therefore, it is preferable to arrange the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2 such that the extension directions of the plurality of first upper electrodes 140 or the plurality of second upper electrodes 142 are different from each other between the first liquid crystal cell 120-1 and the second liquid crystal cell 120-2.

[0154] In any of the above-described modifications 1 to 3, a refractive index distribution can be formed in the liquid crystal layer 154, thus enabling the illumination surface 104 to display a pattern reflecting the shape of multiple regions disposed on each substrate. Therefore, similar to the illumination device 100 according to the first embodiment, an illumination device capable of displaying various patterns without increasing power consumption can be provided.

[0155] The above-described embodiments, which are implementations of the present invention, can be appropriately combined and implemented as long as they do not contradict each other. Furthermore, based on the display devices of each embodiment, any structures in which structural elements are added, deleted, or designed differently, or structures in which processes are added, omitted, or conditions are changed, are included within the scope of the present invention as long as they possess the spirit of the present invention.

[0156] Even if other effects are different from those brought about by the various embodiments described above, those effects that can be clearly obtained according to the description in this specification or that can be easily predicted by those skilled in the art are of course considered to be brought about by the present invention.

[0157] Explanation of reference numerals in the attached figures

[0158] 100... Illumination device; 102-1... Illumination area; 102-2... Illumination area; 102-3... Illumination area; 102-4... Illumination area; 102-5... Illumination area; 102-6... Illumination area; 102-7... Illumination area; 104... Illumination surface; 108... Cover; 110... Light source; 112... Housing; 112a... Inclined surface; 114... Light-emitting element; 116... Lens; 120... Liquid crystal unit; 120-1... First liquid crystal unit; 120-2... Second liquid crystal unit ; 120-3... 3rd liquid crystal unit; 120-4... 4th liquid crystal unit; 122... 1st substrate; 124... 1st region; 126... 2nd region; 128... seal; 130... 2nd substrate; 132... 3rd region; 134... 4th region; 136... 1st lower electrode; 138... 2nd lower electrode; 140... 1st upper electrode; 142... 2nd upper electrode; 144... driving circuit; 146... base film; 148... interlayer insulating film; 150... 1st alignment film; 152... 154...Second alignment film; 164...First signal line; 166...Second signal line; 168...Third signal line; 170...Fourth signal line; 172...Wiring; 174...Wiring; 176...Base film; 178...Interlayer insulating film; 180...Fifth signal line; 182...Sixth signal line; 184...Seventh signal line; 186...Eighth signal line; 188...Wiring; 190...Wiring; 200...S composition; 202...S composition; 204...S composition; 206...P composition Region; 208...P component; 210...P component; 220...5th region; 222...6th region; 224...7th region; 226...8th region; 230...1st substrate; 232...9th region; 234...10th region; 236...1st lower electrode; 238...2nd lower electrode; 240...2nd substrate; 242...11th region; 244...12th region; 246...1st upper electrode; 248...2nd upper electrode; 250...lighting device; 252...upper electrode.

Claims

1. A lighting device comprising: light source; The first liquid crystal unit on the light source; and The second liquid crystal unit on the first liquid crystal unit The first liquid crystal unit and the second liquid crystal unit each have: The first substrate has a first region and a second region; Multiple first lower electrodes are located on the first region and extend along the column direction; Multiple second lower electrodes are located on the second region and extend along the column direction; The first liquid crystal layer on the plurality of first lower electrodes and the plurality of second lower electrodes; and The second substrate on the first liquid crystal layer, The plurality of first lower electrodes and the plurality of second lower electrodes are driven independently of each other. In each of the first liquid crystal unit and the second liquid crystal unit, An alternating voltage is applied to the plurality of first lower electrodes in such a way that the phase is reversed between adjacent first lower electrodes in a row direction that intersects the column direction. An alternating voltage is applied to the plurality of second lower electrodes in such a way that the phase is reversed between adjacent second lower electrodes in the row direction.

2. The lighting device according to claim 1, wherein, Between the first liquid crystal unit and the second liquid crystal unit, the first region overlaps with each other and has the same shape.

3. The lighting device according to claim 1, wherein, In each of the first liquid crystal cell and the second liquid crystal cell, the first region is surrounded by the second region.

4. The lighting device according to claim 1, wherein, In each of the first liquid crystal cell and the second liquid crystal cell, at least one of the plurality of first lower electrodes overlaps with two second lower electrodes selected from the plurality of second lower electrodes in the column direction and is sandwiched by the two second lower electrodes.

5. The lighting device according to claim 1, wherein, The first liquid crystal unit and the second liquid crystal unit each further include: The first alignment film between the first liquid crystal layer and the plurality of first lower electrodes, and between the first liquid crystal layer and the plurality of second lower electrodes; and The second alignment film between the first liquid crystal layer and the second substrate, The orientation direction of the first orientation film intersects with the column direction and the orientation direction of the second orientation film.

6. The lighting device according to claim 1, wherein, The first liquid crystal unit and the second liquid crystal unit each have a separate upper electrode between the first liquid crystal layer and the second substrate.

7. The lighting device according to claim 1, wherein, In each of the first liquid crystal cell and the second liquid crystal cell, the second substrate has a third region and a fourth region that overlap with the first region and the second region, respectively. The first liquid crystal unit and the second liquid crystal unit each further include: Multiple first upper electrodes are located below the third region and extend along a row direction that intersects the column direction; and Multiple second upper electrodes are located below the fourth region and extend along the row direction.

8. The lighting device according to claim 7, wherein, In each of the first liquid crystal unit and the second liquid crystal unit, An alternating voltage is applied to the plurality of first upper electrodes in such a way that the phase is reversed between adjacent first upper electrodes in the column direction. An alternating voltage is applied to the plurality of second upper electrodes in such a way that the phase is reversed between adjacent second upper electrodes in the column direction.

9. The lighting device according to claim 7, wherein, Between the first liquid crystal unit and the second liquid crystal unit, the third region overlaps with each other and has the same shape.

10. The lighting device according to claim 7, wherein, In each of the first and second liquid crystal cells, the first region and the third region overlap and have the same shape.

11. The lighting device according to claim 1, wherein, The lighting device also includes: The third liquid crystal unit on the second liquid crystal unit; and The fourth liquid crystal unit on the third liquid crystal unit. The third liquid crystal unit and the fourth liquid crystal unit each have: The third substrate has a fifth region and a sixth region; Multiple third lower electrodes are located on the fifth region and extend along the column direction; Multiple fourth lower electrodes are located on the sixth region and extend along the column direction; The second liquid crystal layer on the plurality of third lower electrodes and the plurality of fourth lower electrodes; and The fourth substrate on the second liquid crystal layer The plurality of third lower electrodes and the plurality of fourth lower electrodes are driven independently of each other.

12. The lighting device according to claim 11, wherein, In each of the third and fourth liquid crystal units, An alternating voltage is applied to the plurality of third lower electrodes in such a way that the phase is reversed between adjacent third lower electrodes in a row direction that intersects the column direction. An alternating voltage is applied to the plurality of fourth lower electrodes in such a way that the phase is reversed between adjacent fourth lower electrodes in the row direction.

13. The lighting device according to claim 11, wherein, The first region of the first substrate of the first liquid crystal unit or the second liquid crystal unit has a different shape than the fifth region of the third substrate of the third liquid crystal unit or the fourth liquid crystal unit.

14. The lighting device according to claim 11, wherein, Between the third liquid crystal unit and the fourth liquid crystal unit, the fifth region of the third substrate overlaps with each other and has the same shape.

15. The lighting device according to claim 11, wherein, In each of the third and fourth liquid crystal cells, at least one of the plurality of third lower electrodes overlaps with two fourth lower electrodes selected from the plurality of fourth lower electrodes in the column direction and is sandwiched by the two fourth lower electrodes.

16. The lighting device according to claim 11, wherein, The third liquid crystal unit and the fourth liquid crystal unit each further have: The third alignment film between the second liquid crystal layer and the plurality of third lower electrodes, and between the second liquid crystal layer and the plurality of fourth lower electrodes; and The fourth alignment film between the second liquid crystal layer and the fourth substrate, The orientation direction of the third orientation film intersects with the column direction and the orientation direction of the fourth orientation film.

17. The lighting device according to claim 11, wherein, The third liquid crystal unit and the fourth liquid crystal unit each have a separate upper electrode between the second liquid crystal layer and the fourth substrate.

18. The lighting device according to claim 11, wherein, In each of the third and fourth liquid crystal cells, the second substrate has a seventh region and an eighth region that overlap with the fifth region and the sixth region, respectively. The third liquid crystal unit and the fourth liquid crystal unit each further have: Multiple third upper electrodes, located below the seventh region, are arranged in a stripe pattern and extend along a row direction that intersects the column direction; and Multiple fourth upper electrodes, located below the eighth region, are arranged in a stripe pattern and extend along the row direction.

19. An optical element comprising: The first substrate has a first region and a second region; Multiple first lower electrodes are located on the first region and extend along the column direction; Multiple second lower electrodes are located on the second region and extend along the column direction; Liquid crystal layers on the plurality of first lower electrodes and the plurality of second lower electrodes; The second substrate is positioned opposite the first substrate across the liquid crystal layer, and has a third region and a fourth region that overlap with the first region and the second region, respectively. Multiple first upper electrodes are located below the third region and extend along the row direction; as well as Multiple second upper electrodes are located below the fourth region and extend along the row direction. The plurality of first lower electrodes, the plurality of second lower electrodes, the plurality of first upper electrodes, and the plurality of second upper electrodes are driven independently of each other. An alternating voltage is applied to the plurality of first lower electrodes in such a way that the phase is reversed between adjacent first lower electrodes in a row direction that intersects the column direction. An alternating voltage is applied to the plurality of second lower electrodes in such a way that the phase is reversed between adjacent second lower electrodes in the row direction. An alternating voltage is applied to the plurality of first upper electrodes in such a way that the phase is reversed between adjacent first upper electrodes in the column direction. An alternating voltage is applied to the plurality of second upper electrodes in such a way that the phase is reversed between adjacent second upper electrodes in the column direction.

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