Lighting device

Abstract

This lighting device includes: a light source that emits light; an optical element that includes a liquid crystal cell and transmits the light emitted from the light source so as to be able to diffuse; a main body that incorporates the light source and the optical element, and that emits light that passes through the optical element; and a first slide switch that includes a first knob slidably operated with respect to the main body, and that adjusts the light distribution angle of the light emitted from the main body by the sliding operation of the first knob.

Description

lighting equipment

[0001] An embodiment of the present invention relates to a lighting device that controls light distribution using liquid crystal.

[0002] Portable lighting devices, so-called flashlights, can not only irradiate light in a predetermined direction but also have the function of changing the light distribution of the irradiated light, thereby increasing the added value of the product. For example, Patent Document 1 discloses a flashlight that can distribute light by using a reflector to change the focal length of a light bulb, which is the light source of the flashlight.

[0003] JP 2009-9946 A

[0004] In Patent Document 1, by rotating a bezel engaged with a head cover, a reflector disposed within the head cover moves relative to the bulb. In other words, when a user rotates the bezel, which is engaged with a head cover on which an optical component including a flashlight reflector is disposed, the distribution of light emitted from the flashlight changes. However, with the flashlight disclosed in Patent Document 1, the user must hold the flashlight with one hand while operating the bezel with the other. However, such operation is not necessarily convenient and reduces user operability.

[0005] On the other hand, there is known an optical element called a liquid crystal lens, which utilizes the change in refractive index of liquid crystal by adjusting the voltage applied to the liquid crystal. In a lighting device using a liquid crystal lens, it is possible to change the light distribution of the lighting device without changing the focal length of the light source.

[0006] An object of one embodiment of the present invention is to provide a lighting device that is easy for a user to operate and allows for easy adjustment of light distribution.

[0007] An illumination device according to one embodiment of the present invention includes a light source that emits light, an optical element that includes a liquid crystal cell and transmits the light emitted from the light source in a diffusible manner, a main body that incorporates the light source and the optical element and emits light that passes through the optical element, and a first slide switch that includes a first knob that can be slidably operated relative to the main body and that adjusts the light distribution angle of the light emitted from the main body by sliding the first knob.

[0008] 1 is a schematic side view showing the external configuration of a lighting device according to an embodiment of the present invention; FIG. 2 is a schematic top view showing the external configuration of a lighting device according to an embodiment of the present invention; FIG. 3 is a schematic view showing the operation and light distribution of a lighting device according to an embodiment of the present invention; FIG. 4 is a schematic view showing the operation and light distribution of a lighting device according to an embodiment of the present invention; FIG. 5 is a schematic view showing the operation and light distribution of a lighting device according to an embodiment of the present invention; FIG. 6 is a schematic block diagram showing the internal configuration of a lighting device according to an embodiment of the present invention; FIG. 7 is a schematic cross-sectional view showing the configuration of an optical element of a lighting device according to an embodiment of the present invention; FIG. 8 is a schematic cross-sectional view showing the configuration of an optical element of a lighting device according to an embodiment of the present invention; FIG. 9 is a schematic plan view showing the electrode pattern of a liquid crystal cell included in the optical element of a lighting device according to an embodiment of the present invention; FIG. 10 is a schematic plan view showing the electrode pattern of a liquid crystal cell included in the optical element of a lighting device according to an embodiment of the present invention; FIG. 11 is a schematic view illustrating the optical characteristics of a liquid crystal cell included in the optical element of a lighting device according to an embodiment of the present invention; FIG. 12 is a schematic view illustrating the optical characteristics of a liquid crystal cell included in the optical element of a lighting device according to an embodiment of the present invention; FIG. 13 is a schematic view showing a signal input to the optical element of a lighting device according to an embodiment of the present invention; FIG. 14 is a schematic side view showing the external configuration of a lighting device according to an embodiment of the present invention;

[0009] Hereinafter, each embodiment of the present invention will be described with reference to the drawings, etc. However, the present invention can be embodied in various forms without departing from the gist of the technical idea thereof, and should not be construed as being limited to the description of the embodiments exemplified below.

[0010] In order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment, but these are merely examples, and the illustrated shapes themselves do not limit the interpretation of the present invention. Furthermore, in the drawings, components having the same functions as those explained in relation to previous drawings in the specification may be given the same reference numerals even if they are different drawings, and duplicate explanations may be omitted.

[0011] When a single film is processed to form multiple structures, each structure may have a different function or role, and each structure may be formed on a different substrate. However, these multiple structures originate from a film formed as the same layer in the same process and are made of the same material. Therefore, these multiple films are defined as existing in the same layer.

[0012] When expressing the manner in which a structure is placed on top of another structure, the term "above" is used, unless otherwise specified, to include both a case in which another structure is placed directly above, in contact with, a structure, and a case in which another structure is placed above, via yet another structure.

[0013] An illumination device 1 according to one embodiment of the present invention will be described with reference to FIGS. 1A to 6. FIG.

[0014] 1. External Configuration of Illumination Device 1 FIGS. 1A and 1B are a schematic side view and a top view, respectively, showing the external configuration of an illumination device 1 according to one embodiment of the present invention.

[0015] As shown in FIGS. 1A and 1B , the exterior of the lighting device 1 is configured by a main body 10. The main body 10 includes an illumination unit 10a that emits light and a handle unit 10b that is connected to the illumination unit 10a and is held by a user. The lighting device 1 can be used as a flashlight. That is, while holding the handle unit 10b, the user can illuminate their surroundings with light emitted from the illumination unit 10a. Note that the usage of the lighting device 1 is not limited to a flashlight. The lighting device 1 can also be used as a spotlight.

[0016] For ease of explanation, the following description will be given assuming that the optical axis direction of the light emitted from the illumination unit 10a is the z-axis direction. Although the light emission direction is the +z-axis direction, when there is no need to distinguish between the +z-axis direction and the -z-axis direction, the description will simply refer to the z-axis direction. The x-axis and y-axis directions are perpendicular to the z-axis direction, and the x-axis and y-axis directions are perpendicular to each other.

[0017] In a side view, the handle portion 10b extends at a predetermined angle from the z-axis direction. In other words, the handle axis direction, which corresponds to the extension direction of the handle portion 10b, is different from the optical axis direction. When the lighting unit 10a and the handle portion 10b are connected to each other in a bent manner, even when a user uses the lighting device 1 near the user's face, the user can hold the handle portion 10b without applying excessive force to the user's wrist, and the light emitted from the lighting unit 10a can illuminate the user's surroundings. Note that the predetermined angle is, but is not limited to, 15° to 45°. Furthermore, the shape of the main body 10 is not limited to this. The main body 10 can have a shape that corresponds to the usage mode of the lighting device 1.

[0018] The material that constitutes the main body 10 may be a resin material or a metal material.

[0019] The lighting device 1 includes a first slide switch 21 for adjusting the light distribution angle of light emitted from the lighting unit 10a, a second slide switch 22 for adjusting the brightness of the light emitted from the lighting unit 10a, and a changeover switch 23 for switching the light distribution pattern of the light emitted from the lighting unit 10a. The first slide switch 21 includes a first knob 21a operated by a user. The second slide switch 22 includes a second knob 22a operated by a user. The changeover switch 23 includes a push button 23a operated by a user.

[0020] The first knob 21a of the first slide switch 21 and the second knob 22a of the second slide switch 22 are provided on the upper surface of the handle portion 10b, on the side where the handle portion 10b is connected to the illumination unit 10a. The first knob 21a and the second knob 22a are arranged in a direction intersecting the handle axis direction. The upper surface of the handle portion 10b is provided with a first guide groove 10c and a second guide groove 10d extending along the handle axis direction. The first knob 21a and the second knob 22a are slidably fitted into the first guide groove 10c and the second guide groove 10d, respectively. That is, the first knob 21a is operated to slide in the handle axis direction along the first guide groove 10c, and the second knob 22a is operated to slide in the handle axis direction along the second guide groove 10d. Because the first slide switch 21 and the second slide switch 22 have this configuration, for example, the user can operate both the first knob 21a and the second knob 22a using only the thumb of the hand holding the handle portion 10b.

[0021] The push button 23a of the changeover switch 23 is provided on the side of the handle portion 10b. The changeover switch 23 is a so-called push switch. The changeover switch 23 may be a momentary type that maintains an on state only while the push button 23a is pressed, or an alternate type that maintains an on state even after the push button 23a is pressed and released. Furthermore, the changeover switch 23 is not limited to a push switch. The changeover switch 23 may also be a toggle switch, a rocker switch, a slide switch, or the like.

[0022] The positions of the first knob 21a of the first slide switch 21, the second knob 22a of the second slide switch 22, and the push button 23a of the selector switch 23 are not limited to the above-described configuration. The first knob 21a and the second knob 22a may be arranged on the side surface of the handle 10b, and the push button 23a may be arranged on the top surface of the handle 10b.

[0023] Although not shown, a switch may be provided to turn on or off the power supply of the lighting device 1. Alternatively, a configuration in which the power supply of the lighting device 1 can be turned on or off by a changeover switch 23 may also be applied.

[0024] Here, changes in light distribution due to operation of the lighting device 1 will be described with reference to FIGS. 2A to 2D.

[0025] 2A to 2D are schematic diagrams illustrating the operation and light distribution of a lighting device 1 according to one embodiment of the present invention.

[0026] 2A , the first knob 21 a of the first slide switch 21 and the second knob 22 a of the second slide switch 22 are located in the region farthest from the illumination unit 10 a within their respective slidable ranges. In this case, the light 1000 emitted from the illumination unit 10 a has a circular light distribution pattern.

[0027] 2B , when the first knob 21a of the first slide switch 21 is slid, the light 1000 emitted from the lighting unit 10a gradually spreads in the x-axis direction and the y-axis direction. That is, the light distribution angle of the light 1000 emitted from the lighting unit 10a increases. In this way, the light distribution angle of the light 1000 emitted from the lighting unit 10a can be continuously adjusted by sliding the first knob 21a of the first slide switch 21.

[0028] In the lighting device 1, as the light distribution angle of the light 1000 emitted from the lighting unit 10a increases, the luminance of the light 1000 decreases. Therefore, the luminance of the light 1000 is adjusted using the second slide switch 22.

[0029] 2C , when the second knob 22 a of the second slide switch 22 is further slid, the brightness of the light 1000 emitted from the illumination unit 10 a gradually increases. In this way, by sliding the second knob 22 a of the second slide switch 22, the brightness of the light 1000 emitted from the illumination unit 10 a can be continuously adjusted.

[0030] 2A to 2C , when the first knob 21a of the first slide switch 21 is located in the region farthest from the illumination unit 10a within its slidable range, the light distribution angle of the light 1000 is minimum, and when the first knob 21a is located in the region closest to the illumination unit 10a within its slidable range, the light distribution angle of the light 1000 is maximum. However, the sliding operation of the first knob 21a to adjust the light distribution angle of the light 1000 may be reversed from the above-described configuration. Also, when the second knob 22a of the second slide switch 22 is located in the region farthest from the illumination unit 10a within its slidable range, the brightness of the light 1000 is minimum, and when the second knob 22a is located in the region closest to the illumination unit 10a within its slidable range, the brightness of the light 1000 is maximum. However, the sliding operation of the second knob 22a to adjust the brightness of the light 1000 may be reversed from the above-described configuration.

[0031] As described above, in the lighting device 1, the first slide switch 21 can be used to adjust the luminous intensity of the light 1000 emitted from the lighting unit 10a. In addition, in the lighting device 1, the second slide switch 22 can be used to adjust the luminous intensity of the light 1000 emitted from the lighting unit 10a. Furthermore, in the lighting device 1, a user can slide the first knob 21a of the first slide switch 21 and the second knob 22a of the second slide switch 22 with a finger (e.g., a thumb) of the hand holding the handle 10b while holding the handle 10b. Therefore, the user can adjust the luminous intensity and luminous intensity of the light 1000 emitted from the lighting unit 10a with a simple operation using one hand. Furthermore, because the luminous intensity and luminous intensity of the light 1000 change continuously, the user can fine-tune the luminous intensity and luminous intensity of the light 1000.

[0032] Furthermore, in the lighting device 1, the light distribution can be controlled not only by adjusting the light distribution angle but also by switching the light distribution shape.

[0033] 2D , after the first knob 21 a of the first slide switch 21 is slid, the push button 23 a of the changeover switch 23 is pressed. In this case, the light 1000 emitted from the illumination unit 10 a has a linear light distribution pattern extending in the x-axis direction. In this way, by operating the push button 23 a of the changeover switch 23, the light distribution pattern of the light 1000 emitted from the illumination unit 10 a can be switched.

[0034] Although the above description has been given of circular or linear light distribution shapes, the light distribution shape that can be switched by the selector switch 23 is not limited to these shapes. The light 1000 emitted from the illumination unit 10a may have an elliptical or cross-shaped light distribution shape.

[0035] 2. Internal Configuration of Illumination Device 1 FIG. 3 is a schematic block diagram showing the internal configuration of an illumination device 1 according to an embodiment of the present invention.

[0036] As shown in Fig. 3, the main body 10 of the lighting device 1 contains an optical element 30, a light source 40, an optical adjustment unit 50, an optical element drive circuit unit 60, a light source drive circuit unit 70, a battery 80, and a charging module 90. The optical element 30, the light source 40, and the optical adjustment unit 50 are disposed in the lighting unit 10a of the main body 10. The battery 80 and the charging module 90 are disposed in the handle unit 10b of the main body 10. Although Fig. 3 shows the optical element drive circuit unit 60 and the light source drive circuit unit 70 being disposed in the handle unit 10b, the optical element drive circuit unit 60 and the light source drive circuit unit 70 may also be disposed in the lighting unit 10a.

[0037] In the lighting device 1, light emitted from the light source 40 passes through the optical element 30 and is emitted from the lighting unit 10a.

[0038] The optical element driving circuit 60 is electrically connected to the battery 80 and to the optical element 30 via the selector switch 23. The optical element driving circuit 60 receives power from the battery 80 and generates a plurality of signals (e.g., pulse signals including rectangular waves) that drive the optical element 30. The plurality of signals generated by the optical element driving circuit 60 are input to terminals of the optical element 30 selected by the selector switch 23. The optical element driving circuit 60 is also electrically connected to a first slide switch 21. Specifically, the first slide switch 21 is electrically connected to a variable resistor included in the optical element driving circuit 60, and when a first knob 21 a of the first slide switch 21 is slid, the resistance of the variable resistor changes continuously. This allows the amplitude of the potentials included in the plurality of signals to be continuously changed.

[0039] The light source drive circuit 70 is electrically connected to the light source 40 and the battery 80. The light source drive circuit 70 receives power from the battery 80 and generates a signal to drive the light source 40. The light source drive circuit 70 is also electrically connected to the second slide switch 22. Specifically, the second slide switch 22 is electrically connected to a variable resistor included in the light source drive circuit, and when the second knob 22a of the second slide switch 22 is slid, the resistance of the variable resistor changes continuously. This allows the amount of current included in the signal to be continuously changed.

[0040] The battery 80 is electrically connected to the charging module 90. The battery 80 may be a so-called secondary battery (e.g., a lithium-ion battery) that can be repeatedly used by charging. The battery 80 can be charged via the charging module 90. The charging module 90 controls the charging of the battery 80 while preventing overcharging of the battery 80. The battery 80 may be charged either wired or wirelessly. In a wired configuration, the charging module 90 is provided with a terminal for connecting a power cable, and power is charged to the battery 80 via the power cable connected to the terminal of the charging module 90. In a wireless configuration, a power receiving coil is provided in the charging module 90, and power converted by the power receiving coil is charged to the battery 80. The lighting device 1 may also be configured without the charging module 90. In this case, the battery 80 may be a so-called primary battery (e.g., an alkaline battery or a manganese battery) that cannot be recharged.

[0041] The light source 40 emits light to the optical element 30. For example, a light emitting diode (LED) can be used as the light source 40. A plurality of LEDs may be used as the light source 40. When a plurality of LEDs are used as the light source 40, LEDs of the same color may be used, or LEDs of different colors may be used. Note that the light source 40 is not limited to an LED. The light source 40 may be any element or device that can emit light.

[0042] The optical adjusting unit 50 is disposed between the optical element 30 and the light source 40, and converges, diffuses, or reflects the light emitted from the light source 40. For example, the optical adjusting unit 50 is an optical member such as a lens or a reflector, or a combination of these.

[0043] 3. Configuration of Optical Element 30 The optical element 30 controls the light distribution (light distribution angle and light distribution shape) of the light emitted from the illumination unit 10a. Here, the configuration of the optical element 30 will be described with reference to FIGS. 4A to 6B.

[0044] 4A and 4B are schematic cross-sectional views showing the configuration of the optical element 30 of the illumination device 1 according to one embodiment of the present invention. Fig. 4A is a cross-sectional view of the optical element 30 taken along a plane perpendicular to the y-axis direction, and Fig. 4B is a cross-sectional view of the optical element 30 taken along a plane perpendicular to the x-axis direction.

[0045] The optical element 30 includes four liquid crystal cells 100 (a first liquid crystal cell 100-1, a second liquid crystal cell 100-2, a third liquid crystal cell 100-3, and a fourth liquid crystal cell 100-4). In the optical element 30, the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4 are stacked in this order in the z-axis direction, starting from the side closest to the light source 40. Light emitted from the light source 40 is incident on the first liquid crystal cell 100-1 and is emitted from the fourth liquid crystal cell 100-4. In the lighting device 1, the four liquid crystal cells 100 included in the optical element 30 control the diffusion and polarization of light, thereby changing the light distribution of the light emitted from the fourth liquid crystal cell 100-4. In other words, the optical element 30 transmits light emitted from the light source 40 in a diffusible manner and can control the light distribution.

[0046] 4A and 4B show the configuration of the optical element 30 including four liquid crystal cells 100, but the number of liquid crystal cells 100 included in the optical element 30 is not limited to four. The optical element 30 only needs to include at least one liquid crystal cell 100. However, when emitting light having various light distribution shapes, it is preferable that the optical element 30 include at least two liquid crystal cells 100.

[0047] 4A and 4B, each of the first to fourth liquid crystal cells 100-1 to 100-4 includes a first substrate 110-1, a second substrate 110-2, a plurality of first transparent electrodes 120-1, a plurality of second transparent electrodes 120-2, a plurality of third transparent electrodes 120-3, a plurality of fourth transparent electrodes 120-4, a first alignment film 130-1, a second alignment film 130-2, a sealant 140, and a liquid crystal layer 150. The first transparent electrodes 120-1 and the second transparent electrodes 120-2 are alternately provided on the first substrate 110-1. In addition, a first alignment film 130-1 is provided on the first substrate 110-1 so as to cover the first transparent electrodes 120-1 and the second transparent electrodes 120-2. Third transparent electrodes 120-3 and fourth transparent electrodes 120-4 are alternately provided on the second substrate 110-2. A second alignment film 130-2 is provided on the second substrate 110-2 so as to cover the third transparent electrodes 120-3 and the fourth transparent electrodes 120-4. The first substrate 110-1 and the second substrate 110-2 are arranged so that the first transparent electrodes 120-1 and the second transparent electrodes 120-2 face the third transparent electrodes 120-3 and the fourth transparent electrodes 120-4, and are bonded together via a sealant 140 provided on the peripheries of the first substrate 110-1 and the second substrate 110-2. A liquid crystal is sealed in the space surrounded by the first substrate 110-1 (more specifically, the first alignment film 130-1), the second substrate 110-2 (more specifically, the second alignment film 130-2), and the sealing material 140, and a liquid crystal layer 150 is provided between the first substrate 110-1 and the second substrate 110-2.

[0048] An optically elastic resin layer 160 is provided between the first liquid crystal cell 100-1 and the second liquid crystal cell 100-2. Similarly, an optically elastic resin layer 160 is provided between the second liquid crystal cell 100-2 and the third liquid crystal cell 100-3, and between the third liquid crystal cell 100-3 and the fourth liquid crystal cell 100-4. For example, an adhesive containing a light-transmitting acrylic resin can be used as the optically elastic resin layer 160. In other words, the optically elastic resin layer 160 can bond and fix two adjacent liquid crystal cells 100 together.

[0049] Each of the first substrate 110-1 and the second substrate 110-2 may be a rigid substrate having light-transmitting properties, such as a glass substrate, a quartz substrate, or a sapphire substrate. Alternatively, each of the first substrate 110-1 and the second substrate 110-2 may be a flexible substrate having light-transmitting properties, such as a polyimide resin substrate, an acrylic resin substrate, a siloxane resin substrate, or a fluororesin substrate.

[0050] Each of the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4 functions as an electrode for forming an electric field in the liquid crystal layer 150. Each of the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0051] In the first liquid crystal cell 100-1 and the second liquid crystal cell 100-2, the first transparent electrode 120-1 and the second transparent electrode 120-2 extend in the x-axis direction, and the third transparent electrode 120-3 and the fourth transparent electrode 120-4 extend in the y-axis direction. In the third liquid crystal cell 100-3 and the fourth liquid crystal cell 100-4, the first transparent electrode 120-1 and the second transparent electrode 120-2 extend in the y-axis direction, and the third transparent electrode 120-3 and the fourth transparent electrode 120-4 extend in the x-axis direction.

[0052] In the following description, the first transparent electrode 120-1 to the fourth transparent electrode 120-4 may be referred to as the transparent electrodes 120 when no particular distinction is made between them.

[0053] Each of the first alignment film 130-1 and the second alignment film 130-2 aligns the liquid crystal molecules in the liquid crystal layer 150 in a predetermined direction. A polyimide resin or the like is used as each of the first alignment film 130-1 and the second alignment film 130-2. Note that each of the first alignment film 130-1 and the second alignment film 130-2 may be given alignment characteristics by an alignment treatment such as a rubbing method or a photo-alignment method. The rubbing method is a method of rubbing the surface of the alignment film in one direction. The photo-alignment method is a method of irradiating the alignment film with linearly polarized ultraviolet light.

[0054] The first alignment film 130-1 is subjected to an alignment treatment so that the liquid crystal molecules on the first substrate 110-1 side of the liquid crystal layer 150 are aligned in a direction perpendicular to the extension direction of the first transparent electrode 120-1 and the second transparent electrode 120-2. The second alignment film 130-2 is subjected to an alignment treatment so that the liquid crystal molecules on the second substrate 110-2 side of the liquid crystal layer 150 are aligned in a direction perpendicular to the extension direction of the third transparent electrode 120-3 and the fourth transparent electrode 120-4. Therefore, in the first liquid crystal cell 100-1 and the second liquid crystal cell 100-2, the long axes of the liquid crystal molecules on the first substrate 110-1 side are aligned in the y-axis direction, and the long axes of the liquid crystal molecules on the second substrate 110-2 side are aligned in the x-axis direction. In the third liquid crystal cell 100-3 and the fourth liquid crystal cell 100-4, the long axes of the liquid crystal molecules on the first substrate 110-1 side are aligned in the x-axis direction, and the long axes of the liquid crystal molecules on the second substrate 110-2 side are aligned in the y-axis direction.

[0055] An adhesive material containing epoxy resin or acrylic resin is used as the seal material 140. The adhesive material may be an ultraviolet curing type or a thermosetting type.

[0056] The liquid crystal layer 150 can refract light passing through it or change the polarization state of the light passing through it depending on the orientation state of the liquid crystal molecules. Nematic liquid crystal or the like is used as the liquid crystal for the liquid crystal layer 150. The liquid crystal described in this embodiment is a positive type, but a negative type can also be applied by changing the orientation direction of the liquid crystal molecules when no voltage is applied to the transparent electrode 120. In addition, the liquid crystal preferably contains a chiral agent that imparts a twist to the liquid crystal molecules.

[0057] 5A and 5B are schematic plan views showing the electrode patterns of the liquid crystal cell 100 included in the optical element 30 of the lighting device 1 according to one embodiment of the present invention. Specifically, Fig. 5A is a plan view showing the electrode patterns formed on the first substrate 110-1 of the first liquid crystal cell 100-1, and Fig. 5B is a plan view showing the electrode patterns formed on the second substrate 110-2 of the first liquid crystal cell 100-1.

[0058] 5A, a first connection pad 121-1 and a second connection pad 121-2 are provided on a first substrate 110-1. A plurality of first transparent electrodes 120-1 are electrically connected to the first connection pad 121-1. A plurality of second transparent electrodes 120-2 are electrically connected to the second connection pad 121-2.

[0059] As shown in FIG. 5B , a third connection pad 121-3, a fourth connection pad 121-4, a first terminal 122-1, a second terminal 122-2, a third terminal 122-3, and a fourth terminal 122-4 are provided on the second substrate 110-2. The plurality of third transparent electrodes 120-3 are electrically connected to the third terminal 122-3. The plurality of fourth transparent electrodes 120-4 are electrically connected to the fourth terminal 122-4. Furthermore, the third connection pad 121-3 is electrically connected to the first terminal 122-1. The fourth connection pad 121-4 is electrically connected to the second terminal 122-2.

[0060] When the first substrate 110-1 and the second substrate 110-2 are bonded together so that the transparent electrodes 120 face each other, the first connection pad 121-1 and the second connection pad 121-2 overlap with the third connection pad 121-3 and the fourth connection pad 121-4, respectively. A conductive electrode is provided between the first connection pad 121-1 and the third connection pad 121-3, and the first connection pad 121-1 and the third connection pad 121-3 are electrically connected via the conductive electrode. Similarly, a conductive electrode is provided between the second connection pad 121-2 and the fourth connection pad 121-4, and the second connection pad 121-2 and the fourth connection pad 121-4 are electrically connected via the conductive electrode. Therefore, the first transparent electrode 120-1 and the second transparent electrode 120-2 on the first substrate 110-1 are electrically connected to the first terminal 122-1 and the second terminal 122-2, respectively.

[0061] The electrode pattern of the second liquid crystal cell 100-2 is the same as that of the first liquid crystal cell 100-1. The configurations of the electrode patterns of the third liquid crystal cell 100-3 and the fourth liquid crystal cell 100-4 are the same as that of the first liquid crystal cell 100-1, except that the extending direction of the transparent electrode 120 differs by 90°.

[0062] In the liquid crystal cell 100, the first terminal 122-1 to the fourth terminal 122-4 on the second substrate 110-2 are exposed from the first substrate 110-1. In each of the first to fourth liquid crystal cells 100-1 to 100-4, the exposed first terminal 122-1 to the fourth terminal 122-4 are electrically connected to the optical element driving circuit unit 60. As will be described in detail later, signals generated by the optical element driving circuit unit 60 are input to the first terminal 122-1 to the fourth terminal 122-4 of each of the first to fourth liquid crystal cells 100-1 to 100-4, and a predetermined potential is applied to the first transparent electrode 120-1 to the fourth transparent electrode 120-4 of each of the first to fourth liquid crystal cells 100-1 to 100-4. This changes the alignment state of the liquid crystal molecules in the liquid crystal layer 150 of each of the first to fourth liquid crystal cells 100-1 to 100-4, and the distribution of light passing through the optical element 30 can be changed.

[0063] 6A and 6B are schematic diagrams illustrating the optical characteristics of the liquid crystal cell 100 included in the optical element 30 of the lighting device 1 according to one embodiment of the present invention. Specifically, Fig. 6A shows the liquid crystal cell 100 in a state where no voltage is applied to the transparent electrode 120, and Fig. 6B shows the liquid crystal cell 100 in a state where a voltage is applied to the transparent electrode 120.

[0064] As shown in FIG. 6A , the liquid crystal molecules on the first substrate 110-1 side of the liquid crystal layer 150 are aligned in the y-axis direction, and the liquid crystal molecules on the second substrate 110-2 side of the liquid crystal layer 150 are aligned in the x-axis direction. Therefore, when no voltage is applied to any of the first transparent electrode 120-1 to the fourth transparent electrode 120-4, the liquid crystal molecules in the liquid crystal layer 150 are aligned so that they are twisted 90° as they move from the first substrate 110-1 to the second substrate 110-2. Furthermore, the polarization plane (the polarization axis or the direction of the polarization component) of light passing through the liquid crystal layer 150 is rotated 90° in accordance with the alignment direction of the liquid crystal molecules. In other words, the light passing through the liquid crystal layer 150 (more specifically, the polarization component of the light passing through the liquid crystal layer 150) is optically rotated.

[0065] On the other hand, when a voltage is applied so as to generate a potential difference between two adjacent transparent electrodes 120, an electric field (hereinafter referred to as a "transverse electric field") is generated between the two adjacent transparent electrodes 120, and the orientation state of the liquid crystal molecules changes. As shown in Figure 6B, the liquid crystal molecules in the liquid crystal layer 150 are oriented so as to be twisted 90° from the first substrate 110-1 toward the second substrate 110-2, and the liquid crystal molecules near the first substrate 110-1 are aligned in a convex arc shape relative to the first substrate 110-1 due to the transverse electric field between the first transparent electrode 120-1 and the second transparent electrode 120-2, while the liquid crystal molecules near the second substrate 110-2 are aligned in a convex arc shape relative to the second substrate 110-2 due to the transverse electric field between the third transparent electrode 120-3 and the fourth transparent electrode 120-4. The liquid crystal molecules aligned in a convex arc shape have a refractive index distribution, and the polarized component of light along the orientation direction of the liquid crystal molecules is diffused. Furthermore, since the cell gap d, which is the distance between the first substrate 110-1 and the second substrate 110-2, is sufficiently larger than the distance between two adjacent transparent electrodes 120 (for example, 8 μm≦d≦50 μm, preferably 10 μm≦d≦30 μm, and more preferably 15 μm≦d≦25 μm), the electric field formed between the transparent electrodes 120 does not have much effect on the liquid crystal molecules located near the center between the first substrate 110-1 and the second substrate 110-2.

[0066] The light emitted from the light source 40 includes a polarized component in the x-axis direction (hereinafter referred to as the "P-polarized component") and a polarized component in the y-axis direction (hereinafter referred to as the "S-polarized component"), but for convenience, the light incident on the liquid crystal cell 100 will be described below as being divided into a first light 1000-1 having a P-polarized component and a second light 1000-2 having an S-polarized component.

[0067] The P-polarized component of the first light 1000-1 incident on the liquid crystal layer 150 from the first substrate 110-1 is aligned in a direction different from the alignment direction of the liquid crystal molecules on the first substrate 110-1 side, and therefore the first light 1000-1 is not diffused (see (1) in FIG. 6B). Furthermore, the first light 1000-1 is optically rotated while passing through the liquid crystal layer 150, and the polarization component changes from a P-polarized component to an S-polarized component. The S-polarized component of the first light 1000-1 is aligned in a direction different from the alignment direction of the liquid crystal molecules on the second substrate 110-2 side, and therefore the first light 1000-1 is not diffused (see (2) in FIG. 6B).

[0068] The S-polarized component of second light 1000-2 incident on liquid crystal layer 150 from first substrate 110-1 is aligned in the same direction as the alignment direction of the liquid crystal molecules on the first substrate 110-1 side, so second light 1000-2 is diffused in the y-axis direction in accordance with the refractive index distribution of the liquid crystal molecules (see (3) in FIG. 6B). Furthermore, second light 1000-2 is optically rotated while passing through liquid crystal layer 150, and its polarization component changes from an S-polarized component to a P-polarized component. Since the P-polarized component of second light 1000-2 is aligned in the same direction as the alignment direction of the liquid crystal molecules on the second substrate 110-2 side, second light 1000-2 is diffused in the x-axis direction in accordance with the refractive index distribution of the liquid crystal molecules (see (4) in FIG. 6B).

[0069] The above description is of the configuration of one liquid crystal cell 100, but in an optical element 30 including multiple liquid crystal cells 100, each of the multiple liquid crystal cells 100 controls the P-polarized component or S-polarized component of the light incident on the optical element 30.

[0070] 7 is a schematic diagram showing a signal input to the optical element 30 of the lighting device 1 according to one embodiment of the present invention. Fig. 7 shows the signal input to the first liquid crystal cell 100-1 of the optical element 30 and the electrical connection.

[0071] 7 shows the first signal S1 to the fifth signal S5 input to the first liquid crystal cell 100-1 of the optical element 30. The first signal S1 to the fifth signal S5 are generated by the optical element drive circuit unit 60. The first signal S1 and the third signal S3 have a first pulse wave PW1. The second signal S2 and the fourth signal S4 have a second pulse wave PW2. The first pulse wave PW1 and the second pulse wave PW2 are inverted in phase. The fifth signal S5 has a fixed potential P ｆｉｘ The amplitudes of the first pulse wave PW1 and the second pulse wave PW2 and the fixed potential P ｆｉｘThe magnitude of the signal S1 changes continuously by sliding the first knob 21a of the first slide switch 21. The first signal S1, the second signal S2, and the fifth signal S5 are input to the first terminal 122-1 or the second terminal 122-2 via the selector switch 23. The third signal S3 and the fourth signal S4 are input to the third terminal 122-3 and the fourth terminal 122-4, respectively.

[0072] The changeover switch 23 includes a plurality of input-side contacts 23in_1, 23in_2, 23in_3, and 23in_4, and a plurality of output-side contacts 23out_1 and 23out_2. In the changeover switch 23, the output-side contact 23out_1 is electrically connected to one of the input-side contacts 23in_1 and 23in_2, and the output-side contact 23out_2 is electrically connected to one of the input-side contacts 23in_3 and 23in_4. The electrical connections of the output-side contacts 23out_1 and 23out_2 in the changeover switch 23 are interlocked. When the output-side contact 23out_1 is electrically connected to the input-side contact 23in_1, the output-side contact 23out_2 is electrically connected to the input-side contact 23in_3. On the other hand, when the output contact 23out_1 is electrically connected to the input contact 23in_2, the output contact 23out_2 is electrically connected to the input contact 23in_4. Every time the push button 23a of the changeover switch 23 is pressed, the electrical connection between the output contacts 23out_1 and 23out_2 is switched.

[0073] 7, a first signal S1 and a second signal S2 are input to the input side contacts 23in_1 and 23in_3, respectively, and a fifth signal is input to the input side contacts 23in_2 and 23in_4.

[0074] When the output contacts 23out_1 and 23out_2 are electrically connected to the input contacts 23in_1 and 23in_3, respectively, a first signal S1 and a second signal S2 are input to the first terminal 122-1 and the second terminal 122-2, respectively. Also, a third signal S3 and a fourth signal S4 are input to the third terminal 122-3 and the fourth terminal 122-4, respectively.

[0075] In this case, a transverse electric field is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2, causing a change in the orientation of the liquid crystal molecules on the first substrate 110-1 side. Furthermore, a transverse electric field is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4, causing a change in the orientation of the liquid crystal molecules on the second substrate 110-2 side. Therefore, light passing through the first liquid crystal cell 100-1 is diffused in the x-axis and y-axis directions. Therefore, the light emitted from the lighting device 1 has a circular light distribution shape diffused in the x-axis and y-axis directions.

[0076] When the output contacts 23out_1 and 23out_2 are electrically connected to the input contacts 23in_2 and 23in_4, respectively, a fifth signal S5 is input to the first terminal 122-1 and the second terminal 122-2. Also, a third signal S3 and a fourth signal S4 are input to the third terminal 122-3 and the fourth terminal 122-4, respectively. Therefore, a fixed potential P ｆｉｘ is applied to the third transparent electrode 120-3, a first pulse wave PW1 is applied to the third transparent electrode 120-3, and a second pulse wave PW2 is applied to the fourth transparent electrode 120-4.

[0077] In this case, no transverse electric field is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2, and the alignment state of the liquid crystal molecules on the first substrate 110-1 side does not change. On the other hand, a transverse electric field is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4, and the alignment state of the liquid crystal molecules on the second substrate 110-2 side changes. As a result, light passing through the first liquid crystal cell 100-1 is diffused in the x-axis direction. Therefore, the light emitted from the lighting device 1 has a linear light distribution shape elongated in the x-axis direction.

[0078] The size of the light distribution pattern changes depending on the magnitude of the voltage applied to the first transparent electrode 120-1 to the fourth transparent electrode 120-4. In the lighting device 1, the amplitudes of the first pulse wave PW1 and the second pulse wave PW2 input to the first transparent electrode 120-1 to the fourth transparent electrode 120-4 change continuously by sliding the first knob 21a of the first slide switch 21. Therefore, in the lighting device 1, the size of the light distribution pattern can be continuously adjusted by sliding the first knob 21a of the first slide switch 21.

[0079] As described above, in the lighting device 1, the light distribution pattern of the light 1000 emitted from the lighting unit 10a can be switched using the changeover switch 23. Note that in the lighting device 1, an elliptical or cross-shaped light distribution pattern can also be achieved by changing the combination of the first signal S1 to the fifth signal S5 input to the optical element 30.

[0080] <Modification> A description will be given of a lighting device 1A, which is a modification of the lighting device 1, with reference to Fig. 8 . Note that the modification of the lighting device 1 is not limited to the lighting device 1A. Note that, in the following, when the configuration of the lighting device 1A is the same as the configuration of the lighting device 1, the description of the configuration of the lighting device 1A may be omitted.

[0081] FIG. 8 is a schematic side view showing the external configuration of a lighting device 1A according to one embodiment of the present invention.

[0082] In the lighting device 1A, the lighting unit 10a and the handle unit 10b are connected without bending. That is, the handle axis direction of the handle unit 10b is the same as the optical axis direction. Even though the main body 10 has such a shape, a user can hold the handle unit 10b and slide the first knob 21a of the first slide switch 21 and the second knob 22a of the second slide switch 22 with the fingers (e.g., thumb) of the hand holding the handle unit 10b.

[0083] As described above, in the lighting device 1 according to the present embodiment, including the modified examples, the light distribution and luminance of the light 1000 emitted from the lighting unit 10a can be adjusted by a simple operation. In other words, the light distribution and luminance can be easily adjusted in the lighting device 1. Furthermore, because the light distribution angle and luminance of the light 1000 change continuously, the user can fine-tune the light distribution angle and luminance of the light 1000.

[0084] It is understood that within the scope of the concept of the present invention, those skilled in the art may make various modifications and alterations, and that these modifications and alterations also fall within the scope of the present invention. For example, even if a person skilled in the art appropriately adds, deletes, or modifies the design of the above-described embodiments, or adds, omits, or modifies the conditions of steps, these modifications are also included within the scope of the present invention as long as they maintain the gist of the present invention.

[0085] Furthermore, other effects and advantages brought about by each embodiment that are clear from the description in this specification or that can be appropriately conceived by a person skilled in the art are naturally understood to be brought about by the present invention.

[0086] 1, 1A: lighting device, 10: main body, 10a: lighting unit, 10b: handle, 10c: first guide groove, 10d: second guide groove, 21: first slide switch, 21a: first knob, 22: second slide switch, 22a: second knob, 23: changeover switch, 23a: push button, 23in: input side contact, 23out: output side contact, 30: optical element, 40: light source, 50: optical adjustment unit, 60: optical element drive circuit unit, 70: light source drive circuit unit, 80: battery, 90: charging module, 100: liquid crystal cell, 100-1: first liquid crystal cell, 100-2: second liquid crystal cell, 100-3: third liquid crystal cell, 100-4: fourth liquid crystal cell, 110-1: First substrate, 110-2: Second substrate, 120: Transparent electrode, 120-1: First transparent electrode, 120-2: Second transparent electrode, 120-3: Third transparent electrode, 120-4: Fourth transparent electrode, 121-1: First connection pad, 121-2: Second connection pad, 121-3: Third connection pad, 121-4: Fourth connection pad, 122-1: First terminal, 122-2: Second terminal, 122-3: Third terminal, 122-4: Fourth terminal, 130-1: First alignment film, 130-2: Second alignment film, 140: Sealing material, 150: Liquid crystal layer, 160: Optical elastic resin layer, 1000: Light, 1000-1: First light, 1000-2: Second light

Claims

1. An illumination device comprising: a light source that emits light; an optical element including a liquid crystal cell that transmits the light emitted from the light source in a diffusible manner; a main body that incorporates the light source and the optical element and irradiates the light that transmits through the optical element; and a first slide switch that includes a first knob that is slidably operated with respect to the main body, and that adjusts the light distribution angle of the light irradiated from the main body by sliding the first knob.

2. The lighting device according to claim 1, wherein the first slide switch is connected to the optical element, and the sliding operation of the first knob continuously changes the magnitude of the voltage applied to the transparent electrode included in the liquid crystal cell.

3. The lighting device of claim 1, further comprising a second knob that is slidably operated relative to said body, and a second slide switch that adjusts the brightness of the light emitted from said body by sliding said second knob.

4. The lighting device according to claim 3, wherein the second slide switch is connected to the light source, and the amount of current supplied to the light source changes continuously by the sliding operation of the second knob.

5. The lighting device according to claim 1, wherein the main body includes an illumination unit that irradiates the light, and a handle unit that is connected to the illumination unit and on which the first knob is mounted, and the optical axis direction of the light irradiated from the illumination unit is different from a handle axis direction along which the handle unit extends.

6. The lighting device according to claim 1, wherein the main body includes an illumination unit that irradiates the light, and a handle unit that is connected to the illumination unit and on which the first knob is mounted, and the optical axis direction of the light irradiated from the illumination unit is the same as the handle axis direction along which the handle unit extends.

7. The lighting device according to claim 5 or 6, wherein the first knob is slidable in the handle axis direction.

8. The lighting device of claim 1, further comprising a second knob that is slidably operated relative to the main body and a second slide switch that adjusts the brightness of the light emitted from the main body by sliding the second knob, wherein the main body includes: an illumination unit that irradiates the light; and a handle unit that is connected to the illumination unit and on which the first knob and the second knob are disposed; and wherein the first knob and the second knob are arranged along a direction intersecting with the handle axis direction.

9. The lighting device according to claim 1, further comprising a changeover switch connected to said optical element for changing the light distribution shape of said light irradiated from said main body.