Lighting device

Abstract

A lighting device according to the present disclosure comprises: a liquid crystal layer formed between a first substrate and a second substrate; a pattern electrode layer disposed between the first substrate and the liquid crystal layer and formed by arranging a plurality of electrodes in a predetermined pattern; a ground electrode layer disposed between the second substrate and the liquid crystal layer; and a control unit (10) that controls the voltage applied to the pattern electrode layer. The lighting device also includes: a liquid crystal lens array (3) formed by a collection of a plurality of liquid crystal lenses which are each formed by an individual electrode of the pattern electrode layer; and a light source (1) that projects light onto the liquid crystal lens array, the light being transmitted through the liquid crystal lens array. The control unit controls the voltage to each of the electrodes and thereby controls the state of the transmission of the light through the liquid crystal lens array. The liquid crystal lens array is disposed so as to radiate, onto a predetermined object, the light transmitted through the liquid crystal lens array, such light serving as illumination light.

Description

lighting equipment

[0001] The present disclosure relates to a lighting device using a liquid crystal lens array.

[0002] As described in Patent Literature 1, a liquid crystal lens array has been developed that utilizes the property of liquid crystals, that is, the refractive index changes depending on voltage. Specifically, Patent Literature 1 describes a lighting control device that does not have any moving parts, in which the focal length of the liquid crystal lens is changed by variably adjusting the voltage of electrodes sandwiching a liquid crystal layer. As an example, Patent Literature 1 describes that the liquid crystal lens array can be used as a three-dimensional display device that takes horizontal parallax into consideration in information processing terminals such as smartphones and tablet terminals.

[0003] JP 2014-112157 A

[0004] However, the above-mentioned Patent Document 1 only describes the use of the liquid crystal lens array as a 3D display device, and does not describe any other applications, which poses a problem that the liquid crystal lens cannot be used in a more effective manner.

[0005] Therefore, an object of the present disclosure is to solve the above-mentioned problem of being unable to further utilize liquid crystal lenses.

[0006] a liquid crystal lens array formed by an assembly of a plurality of liquid crystal lenses, each of which is formed by each of the electrodes of the patterned electrode layer; and a light source that irradiates light onto the liquid crystal lens array and transmits the light through the liquid crystal lens array, wherein the control unit controls the voltage applied to each of the electrodes to control the transmission state of light from the liquid crystal lens array, and the liquid crystal lens array is arranged to irradiate a predetermined object with the light transmitted through the liquid crystal lens array as illumination light.

[0007] In addition, the lighting device is configured such that the control unit controls the focus of the light as the illumination light transmitted through the liquid crystal lens array by controlling the voltage applied to each of the electrodes.

[0008] In addition, the lighting device is configured such that the control unit controls the voltage to each of the electrodes in accordance with the arrangement of the electrodes.

[0009] In addition, in the lighting device, the control unit controls the voltage to each of the electrodes belonging to each electrode group, each electrode group being made up of a plurality of the electrodes set in accordance with the arrangement of the electrodes.

[0010] In addition, the lighting device is configured such that the control unit performs control so as to apply a voltage only to each of the electrodes belonging to a specific electrode group.

[0011] The lighting device further comprises a collimator lens through which light from the light source is incident and exits to the liquid crystal lens array.

[0012] Furthermore, an illumination device according to one embodiment of the present disclosure comprises a liquid crystal lens including: a first substrate and a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; an electrode layer disposed between the first substrate and the liquid crystal layer; a ground electrode layer disposed between the second substrate and the liquid crystal layer; and a control unit that controls a voltage applied to the electrode layer; a light source that irradiates light onto the liquid crystal lens and transmits the light from the liquid crystal lens; and a collimator lens that receives light from the light source and emits the light towards the liquid crystal lens, wherein the control unit controls the voltage applied to the electrode layer to control the transmission state of light from the liquid crystal lens; and the liquid crystal lens is arranged to irradiate a predetermined object with the light transmitted through the liquid crystal lens as illumination light.

[0013] With the above-described configuration, the present disclosure can further utilize liquid crystal lenses.

[0014] It is a diagram showing an example of the configuration of the lighting device according to the present disclosure. It is a diagram showing an example of the configuration of the liquid crystal lens array disclosed in Fig. 1. It is a diagram showing an example of the configuration of the liquid crystal lens array disclosed in Fig. 1.

[0015] First Embodiment The present disclosure will be described with reference to the drawings. Fig. 1 shows an outline of the configuration of a lighting device, and Figs. 2 and 3 show an outline of the configuration of a liquid crystal lens array.

[0016] The lighting device in this embodiment uses a liquid crystal lens array 3, as will be described later, and irradiates a predetermined object with light transmitted through the liquid crystal lens array 3. As shown in Fig. 1, the lighting device includes a light source 1, a collimator lens 2, and the liquid crystal lens array 3.

[0017] The light source 1 is installed, for example, at a predetermined location, and irradiates light onto the collimator lens 2. For example, the light source 1 is an LED light source or a laser light source.

[0018] The collimator lens 2 is a lens configured to receive light emitted from the light source 1 and output parallel light. The collimator lens 2 is disposed at a position a predetermined distance from the light source 1, receives light from the light source 1, and outputs parallel light to the liquid crystal lens array in response. Note that the collimator lens 2 is not necessarily provided, and the light from the light source 1 may be incident on the liquid crystal lens array via another lens or without a lens.

[0019] The liquid crystal lens array 3 includes a patterned electrode layer formed by arranging a plurality of electrodes in a predetermined pattern, and each electrode in the patterned electrode layer forms a liquid crystal lens, resulting in a collection of the plurality of liquid crystal lenses. Specifically, the liquid crystal lens array 3 includes a liquid crystal layer formed between a first substrate and a second substrate, a patterned electrode layer disposed between the first substrate and the liquid crystal layer and formed by arranging a plurality of electrodes in a predetermined pattern, a ground electrode layer disposed between the second substrate and the liquid crystal layer, and a control unit 10 that controls the voltage applied to the patterned electrode layer. An insulating layer and a high-resistance layer are also disposed between the patterned electrode layer and the liquid crystal layer. Each of the substrates, electrode layers, and other components are all made of transparent materials.

[0020] The patterned electrode layer includes a plurality of first electrodes and a plurality of second electrodes, as described in Patent Document 1, for example, and a liquid crystal lens is formed at the location where a pair of the first electrode and the second electrode is arranged. Specifically, a voltage is applied by the control unit 10, and the orientation of the liquid crystal molecules in the liquid crystal layer between one first electrode and one second electrode and the ground electrode changes, thereby forming a liquid crystal lens. As a result, the liquid crystal lens array 3 in this embodiment is configured by arranging a plurality of liquid crystal lenses 31, as shown in FIG. 2. Note that the configuration of the liquid crystal lens array 3 can be realized by a known liquid crystal lens array such as that described in Patent Document 1, and since various configurations of liquid crystal lens arrays are known, detailed configuration description will be omitted.

[0021] In the liquid crystal lens array 3 of this embodiment, the liquid crystal lenses 31 are arranged in a grid pattern as shown in Fig. 2. Furthermore, in the liquid crystal lens array 3, groups (electrode groups) consisting of a plurality of liquid crystal lenses 31 are formed according to the arrangement of the liquid crystal lenses 31 as shown in Fig. 3. For example, a group G1 is formed by a plurality of liquid crystal lenses 31 arranged in the upper left position of the liquid crystal lens array 3. Similarly, a group G2 is formed by a plurality of liquid crystal lenses 31 arranged in the upper right position of the liquid crystal lens array 3, a group G3 is formed by a plurality of liquid crystal lenses 31 arranged in the lower left position of the liquid crystal lens array 3, and a group G4 is formed by a plurality of liquid crystal lenses 31 arranged in the lower right position of the liquid crystal lens array 3. The arrangement position and group of each liquid crystal lens 31 are associated with the position of the electrode corresponding to each liquid crystal lens 31 and are stored so as to be identifiable by the control device 10.

[0022] The control unit 10 controls to change the focal length of each liquid crystal lens 31 by variably adjusting the voltage applied to each electrode constituting each liquid crystal lens 31. For example, the control unit 10 controls the illumination light emitted from the liquid crystal lens array 3 to be condensed at a predetermined focal length as shown by reference symbol L1 in Fig. 1, controls the illumination light emitted from the liquid crystal lens array 3 to be parallel as shown by reference symbol L2, or controls the illumination light emitted from the liquid crystal lens array 3 to be diffused as shown by reference symbol L3.

[0023] Furthermore, the control unit 10 may control the voltage for each electrode constituting each liquid crystal lens 31. For example, the control unit 10 may change the voltage applied to the corresponding electrode depending on the arrangement position of each liquid crystal lens 31. As an example, the control unit 10 may control the voltage so that the focal length of a liquid crystal lens 31 at one position differs from that of a liquid crystal lens 31 at another position, or may control the voltage so that the intensity of illumination light from a liquid crystal lens 31 at one position differs from that of a liquid crystal lens 31 at another position.

[0024] More specifically, when the liquid crystal lenses 31 of the liquid crystal lens array 3 are classified into groups according to their arrangement as shown in FIG. 3 , the control unit 10 may vary and control the voltages applied to the electrodes corresponding to the liquid crystal lenses 31 belonging to each group. For example, the control unit 10 may control the liquid crystal lenses 31 belonging to only group G1 to emit illumination light, and the liquid crystal lenses 31 belonging to the other groups G2, G3, and G4 to emit no illumination light. Furthermore, for example, the control unit 10 may control the illumination light irradiation states of the groups G1, G2, G3, and G4 to be different from one another. For example, the illumination light from group G1 may be focused at a certain focal length, the illumination light from group G2 may be focused at a different focal length, the illumination light from group G3 may be emitted in parallel, and the illumination light from group G4 may be emitted in a diffused manner. Note that the above-described illumination control is merely an example, and the voltages applied to the electrodes corresponding to each liquid crystal lens 31 may be controlled so that the illumination light irradiation states of each liquid crystal lens 31 are different.

[0025] As described above, by configuring a lighting device using the liquid crystal lens array 3, the following applications become possible. For example, by using it as a compact lighting device to illuminate a surgical target in a hospital operating room, the position and size of the focused light spot illuminating the surgical target area can be changed. The compact lighting device can also be used, for example, as a projector or headlight. Furthermore, by using it as a large lighting device in a stadium such as a baseball field, it can focus light on the mound to illuminate only the mound, or it can brightly illuminate the entire stadium. Furthermore, by using it as an ultra-compact lighting device in a microscope, the position and size of the illuminated spot can be changed to match the size of the subject. Note that the above-mentioned examples of lighting devices using liquid crystal lens arrays in the present disclosure are merely examples, and the applications of the lighting device are not limited to those described above, and any lighting device may be used.

[0026] Although the lighting device described above is configured using a liquid crystal lens array, it may also be configured using a single liquid crystal lens. That is, the liquid crystal lens array 3 shown in FIG. 1 may be replaced with a single liquid crystal lens, light may be irradiated from the light source 1 onto the collimator lens 2, and the collimated light from the collimator lens 2 may be emitted onto the single liquid crystal lens. The control unit 10 may control the voltage applied to the liquid crystal lens to control the focal length of the illumination light emitted from the single liquid crystal lens. This may allow the size of the spot of illumination light emitted from the single liquid crystal lens to be reduced and used as a spotlight, or alternatively, the lighting device may emit illumination light that brightly illuminates the entire area without concentrating the illumination light. In this way, a lighting device for various applications can be realized with a simple configuration.

[0027] Although the present disclosure has been described above with reference to the above-described embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each of the above-described embodiments can be combined with other embodiments as appropriate.

[0028] The present invention claims the benefit of priority based on patent application No. 2023-107059 filed in Japan on June 29, 2023, and all of the contents disclosed in the patent application are included in this specification.

[0029] REFERENCE SIGNS LIST 1 Light source 2 Collimator lens 3 Liquid crystal lens array 31 Liquid crystal lens 10 Control unit

Claims

1. An illumination device comprising: a first substrate and a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; a patterned electrode layer disposed between the first substrate and the liquid crystal layer and formed with a plurality of electrodes arranged in a predetermined pattern; a ground electrode layer disposed between the second substrate and the liquid crystal layer; a control unit for controlling a voltage applied to the patterned electrode layer; a liquid crystal lens array formed by an assembly of a plurality of the liquid crystal lenses, each liquid crystal lens being formed by each of the electrodes of the patterned electrode layer; and a light source for irradiating light onto the liquid crystal lens array and transmitting the light through the liquid crystal lens array, wherein the control unit controls the voltage applied to each of the electrodes to control the transmission state of light from the liquid crystal lens array, and the liquid crystal lens array is disposed to irradiate a predetermined object with the light transmitted through the liquid crystal lens array as illumination light.

2. A lighting device according to claim 1, wherein the control unit controls the focus of the light as the illumination light transmitted through the liquid crystal lens array by controlling the voltage applied to each of the electrodes.

3. A lighting device according to claim 1, wherein the control unit controls the voltage to each of the electrodes in accordance with the arrangement of the electrodes.

4. A lighting device according to claim 3, wherein the control unit controls the voltage to each of the electrodes belonging to each electrode group, the electrode group being composed of a plurality of the electrodes set in accordance with the arrangement of the electrodes.

5. A lighting device according to claim 4, wherein the control unit controls so that a voltage is applied only to each of the electrodes belonging to a specific electrode group.

6. An illumination device according to claim 1, comprising a collimator lens through which light from said light source is incident and exits to said liquid crystal lens array.

7. A lighting device comprising: a liquid crystal lens including a first substrate and a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; an electrode layer disposed between the first substrate and the liquid crystal layer; a ground electrode layer disposed between the second substrate and the liquid crystal layer; and a control unit that controls a voltage applied to the electrode layer; a light source that irradiates light onto the liquid crystal lens and transmits the light from the liquid crystal lens; and a collimator lens through which light from the light source is incident and exits to the liquid crystal lens, wherein the control unit controls the voltage applied to the electrode layer to control the transmission state of light from the liquid crystal lens, and the liquid crystal lens is arranged to irradiate the light transmitted through the liquid crystal lens as illumination light onto a predetermined object.

Images