JP6429114B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device.

  Recently, various types of lighting devices have been proposed. For example, the illumination device disclosed in Patent Document 1 includes a light emitting element, a mirror that reflects light emitted from the light emitting element, and a scanning device (scanning actuator) that changes the direction of the mirror at high speed. . In this illuminating device, the scanning device drives the mirror at a high speed to control the light distribution of the illuminating device.

JP 2014-89990 A

  However, the illumination device disclosed in Patent Document 1 uses a scanning device that operates at high speed, a mirror that is driven at high speed, and a plurality of light emitting elements. In this apparatus, for example, when a surface-emitting light source in which the light output and the light source area are proportional, such as an LED, is used, it is assumed that it is difficult to collect light on the scanning device. There is a problem that light distribution control is not easy. In addition, when using a light source with a small light source area, such as a laser, that has a high light output, it is assumed that a design that takes safety into consideration in combination with the scanning device is required, and it is difficult to achieve a high light output. The The present invention has been made in consideration of such points, and an object of the present invention is to provide an illuminating device capable of highly controlling light distribution and taking into consideration the light safety of emitted light. .

The lighting device according to the present invention comprises:
A light source device;
A light distribution controller including a plurality of optical elements for adjusting the optical path of the light emitted from the light source device,
The light distribution controller includes a holographic polymer dispersed liquid crystal element capable of switching between a state of diffracting light of a specific linearly polarized light component and a state of transmitting the light as one or more of the plurality of optical elements, Including
The light diffracted by the holographic polymer-dispersed liquid crystal element may illuminate a region that is at least partially different from the light emitted from another optical element.

  In the illumination device according to the present invention, the plurality of optical elements include a first optical element made of the holographic polymer dispersed liquid crystal element and the holographic light emitted from the light source device to form the first optical element. And a second optical element disposed on the optical path of the light transmitted through the polymer dispersion type liquid crystal element.

In the lighting device according to the present invention,
The light distribution controller includes a plurality of holographic polymer dispersed liquid crystal elements,
The light diffracted by the plurality of holographic polymer dispersed liquid crystal elements may at least partially illuminate different regions.

  In the illumination device according to the present invention, the plurality of holographic polymer dispersed liquid crystal elements are arranged side by side so that light emitted from the light source device can sequentially pass through the plurality of holographic polymer dispersed liquid crystal elements. May be.

The illumination device according to the present invention further comprises a polarization conversion element that can be disposed between two adjacent holographic polymer dispersed liquid crystal elements,
The polarization conversion element may function as a half-wave plate for linearly polarized light.

  In the illuminating device according to the present invention, the plurality of optical elements may be arranged so as to be positioned on optical paths of different light beams emitted from the light source device.

  In the illuminating device according to the present invention, the plurality of optical elements may be arranged on a single plane irradiated with light from the light source device.

  In the illumination device according to the present invention, the light transmitted through the holographic polymer dispersed liquid crystal element may illuminate a region within a region illuminated by light emitted from any other optical element.

  In the illumination device according to the present invention, the light source device may emit light of the specific linearly polarized light component.

The illumination device according to the present invention further comprises object detection means capable of detecting an object to be detected,
The switching of the state of the holographic polymer dispersed liquid crystal element may be controlled based on the detection result of the object detection means.

  ADVANTAGE OF THE INVENTION According to this invention, the light distribution of the illumination light from an illuminating device can be stabilized and highly adjusted, fully considering light safety.

FIG. 1 is a side view illustrating a lighting device for explaining a first embodiment of the present invention. FIG. 2 is a side cross-sectional view showing a holographic polymer dispersed liquid crystal element that can be incorporated into a lighting device. FIG. 3 is a diagram showing the holographic polymer dispersed liquid crystal element in FIG. 2 in a state different from that in FIG. FIG. 4 is a view for explaining a method of manufacturing the holographic polymer dispersed liquid crystal element of FIGS. FIG. 5 is a view showing a modification of the illumination device of FIG. FIG. 6 is a side view showing the lighting device for explaining the second embodiment of the present invention. FIG. 7 is a diagram illustrating the illumination device of FIG. 6, and illustrates a state where illumination is performed with a light distribution different from that in FIG. 6. FIG. 8 is a diagram for explaining a region illuminated using the illumination device of FIG.

  Hereinafter, several embodiments of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  In addition, as used in this specification, the shape and geometric conditions and the degree thereof are specified, for example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. are strictly Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  1-5 is a figure for demonstrating the 1st Embodiment of this invention and its modification. The first embodiment will be described with reference to FIGS. FIG. 1 is a side view schematically showing an installation state of the lighting device, and FIGS. 2 to 4 are diagrams for explaining a holographic polymer dispersed liquid crystal element that can be applied to the lighting device of FIG. is there. The illumination device 10 illustrated in FIG. 1 includes a light source device 15 and a light distribution control tool 20 that adjusts the optical path of light emitted from the light source device 15 to control light distribution. The light distribution control tool 20 has a plurality of optical elements that can change the optical path of the light emitted from the light source device 15. In the example shown in FIG. 1, the light distribution control tool 20 includes first to third optical elements 21, 22, and 23. In particular, the light distribution control tool 20 includes a holographic polymer dispersed liquid crystal element 40, that is, an HPDLC 40, as one or more of the plurality of optical elements 21, 22, and 23.

  First, various light sources can be used as the light source device 15. However, a laser light source that can easily control the polarization state of the generated light can be suitably used in combination with the holographic polymer dispersed liquid crystal element 40 that forms one or more of the plurality of optical elements. Moreover, the wavelength range of the light emitted from the light source device 15 can be appropriately adjusted according to the color desired for the illumination light. In particular, the light source device 15 may emit a plurality of bands of light and express a desired color by additive color mixing of the plurality of bands of light.

  Next, the light distribution control tool 20 will be described. The holographic polymer dispersed liquid crystal element 40 constituting one or more of the plurality of optical elements 21, 22, 23 has a diffraction state shown in FIG. 2 that diffracts light of a specific linearly polarized light component, for example, P wave light. The element changes its state between the transmission state shown in FIG. 3 that transmits light of the specific linearly polarized light component, for example, P-wave light. As shown in FIGS. 2 and 3, switching between the diffraction state and the transmission state can be controlled by the presence or absence of voltage application. The holographic polymer dispersion type liquid crystal element 40 is configured so that the other linearly polarized light component that vibrates in a direction orthogonal to the vibration direction of the specific linearly polarized light component, for example, S-wave light, is not subjected to voltage application. Regardless, it can be transmitted without being diffracted.

  As shown in FIGS. 2 and 3, the holographic polymer dispersed liquid crystal element 40 includes an element layer 41 capable of causing a diffraction phenomenon, a pair of electrode layers 45 provided on both sides of the element layer 41, And a pair of base materials 46 provided on both outer sides of the electrode layer 45. The electrode layer 45 and the base material 46 are light transmissive, and in particular, in the illustrated lighting device 10, they are visible light transmissive. The substrate 46 can be formed using, for example, glass or a resinous substrate, and the electrode layer 45 can be formed using a transparent conductor such as ITO. The element layer 41 includes a polymer layer 42 and a liquid crystal layer 43.

  The element layer 41 has a periodic structure by repeatedly arranging the polymer layer 42 and the liquid crystal layer 43. When the polymer layer 42 and the liquid crystal layer 43 have a difference in refractive index, the element layer 41 functions as a hologram and can diffract light in a specific wavelength band incident from a specific incident angle with high efficiency. In the illustrated example, the liquid crystal layer 43 includes liquid crystal molecules 44 having a longitudinal direction. The liquid crystal molecules 44 have birefringence, and the refractive index along the longitudinal direction is higher than the refractive index in an arbitrary direction orthogonal to the longitudinal direction. In addition, the refractive index in an arbitrary direction orthogonal to the longitudinal direction of the liquid crystal molecules 44 does not cause an effective refractive index difference with the polymer layer 42.

  As shown in FIG. 2, in a state where no voltage is applied, the liquid crystal molecules 44 in the liquid crystal layer 43 are aligned in a direction connecting the two polymer layers 42 adjacent to the liquid crystal layer 43. In the state shown in FIG. 2, the P wave oscillating in a direction parallel to the paper surface of FIG. 2 is diffracted by the element layer 41 functioning as a transmission hologram. On the other hand, as shown in FIG. 3, when a voltage is applied between the pair of electrode layers 45, the liquid crystal molecules 44 are aligned in the direction connecting the pair of electrodes 45. In the state shown in FIG. 3, the polymer layer 42 and the liquid crystal layer 43 do not cause an effective refractive index difference with respect to the incident light to the element layer 41. Therefore, the P wave passes straight through the element layer 41 without being diffracted by the element layer 41 to which a voltage is applied.

  2 and 3, the polymer layer 42 and the liquid crystal layer 43 are either in the state of FIG. 2 in which no voltage is applied or in the state of FIG. 3 in which a voltage is applied. In this case, no difference in refractive index is caused. Therefore, the S wave passes through the element layer 41 without being diffracted by the element layer 41 regardless of whether or not a voltage is applied between the pair of electrode layers 45.

  The element layer 41 of such a holographic polymer dispersion type liquid crystal element 40 is produced using the same method as a volume hologram using a normal photopolymer. Specifically, first, a film of a photocurable resin composition containing liquid crystal molecules 44 having refractive index anisotropy is formed. Next, as shown in FIG. 3, this film is exposed to object light Lo and reference light Lr having coherence. By overlapping the object light Lo and the reference light Lr, bright and dark interference fringes are generated in the resin composition film. As a result, the monomer 42a reacts in the light portion 41a to generate a polymer chain 42b, and the polymer chain 42b forms the polymer layer 42. On the other hand, the liquid crystal molecules 44 gather in the dark portions 41 b of the interference fringes to form the liquid crystal layer 43. Further, along with the polymerization shrinkage of the monomer in the photocurable resin, both ends in the longitudinal direction of the liquid crystal molecules 44 are drawn to the polymer chain 42b forming the polymer layer 42. As a result, the liquid crystal molecules 44 are Orient. In this way, the element layer 41 is formed.

  In the illustrated example, the holographic polymer dispersed liquid crystal element 40 may be fabricated so as to reproduce an image of the scattering plate in the diffraction state. The holographic polymer dispersed liquid crystal element 40 capable of reproducing the image of the scattering plate can be manufactured by using the scattered light from the actual scattering plate as the object light. In this example, the reproduction illumination light traveling in the opposite direction to the reference light composed of the parallel light beam used when producing the holographic polymer dispersed liquid crystal element 40 is applied to the liquid crystal element 40 using the light source device 15. When irradiated, a reproduced image of the scattering plate is generated at the arrangement position of the scattering plate that is the source of the object light used when the liquid crystal element 40 is manufactured. If the scattering plate that is the source of the object light used in manufacturing the liquid crystal element 40 has a uniform surface scattering, the reproduced image of the scattering plate obtained by the liquid crystal element 40 is also a uniform surface illumination. Become.

  The light diffracted by one holographic polymer dispersed liquid crystal element 40 illuminates a region at least partially different from the light emitted from other optical elements included in the light distribution control tool 20. In the illumination device 10 shown in FIG. 1, the light distribution control tool 20 includes a plurality of holographic polymer dispersed liquid crystal elements 40. That is, each of the first to third optical elements 21, 22, and 23 includes the holographic polymer dispersed liquid crystal element 40. The light diffracted by the plurality of holographic polymer dispersed liquid crystal elements 40 illuminates different regions at least partially.

  In the example shown in FIG. 1, the light Ld1 diffracted by the holographic polymer dispersed liquid crystal element 40 forming the first optical element 21 illuminates the first illuminated area Z1. The light Ld2 diffracted by the holographic polymer dispersed liquid crystal element 40 constituting the second optical element 22 illuminates the second illuminated area Z2. The light Ld3 diffracted by the holographic polymer dispersed liquid crystal element 40 constituting the third optical element 23 illuminates the third illuminated area Z3. The first illuminated area Z1 and the second illuminated area Z2 overlap only partly, and the second illuminated area Z2 and the third illuminated area Z3 overlap only partly. On the other hand, the first illuminated area Z1 and the third illuminated area Z3 are separated from each other and do not overlap even partly.

  Here, in the example shown in FIG. 1, a region that is actually irradiated with illumination light by the illumination device 10 is assumed as a near-field illuminated region. On the other hand, it can be assumed that the area illuminated by the illumination device is the illuminated area of the far field. The illuminated area of the far field is usually not expressed as a region having a desired area, but is often expressed as a diffusion angle distribution in an angular space located closer to the optical element than the region that is actually illuminated. Therefore, the term “illuminated area” includes a diffusion angle range in an angle space in addition to an illuminated area irradiated with actual illumination light. Therefore, the illuminated field in the near field can also be determined by a diffusion angle distribution for illuminating the illuminated area with a desired area. For example, in the example shown in FIG. 1, the region where the reproduction image of the scattering plate reproduced by the holographic polymer dispersed liquid crystal element 40 is generated is the first to third regions that are actually irradiated with illumination light. Compared to the illuminated area Z1, it may be a near-field area.

  As shown in FIG. 1, each holographic polymer dispersed liquid crystal element 40 is provided with an application means 51 separately. As a result, the holographic polymer dispersed liquid crystal element 40 constituting each of the optical elements 21, 22, and 23 can be switched between the diffraction state and the transmission state independently of the other holographic polymer dispersed liquid crystal elements 40. It is like that.

  In particular, in the illuminating device 10 shown in FIG. 1, a plurality of holographic polymer dispersed liquid crystals are transmitted so that light emitted from the light source device 15 can sequentially pass through the plurality of holographic polymer dispersed liquid crystal elements 40. The elements 40 are arranged side by side on a straight line. That is, the plurality of holographic polymer dispersed liquid crystal elements 40 are sequentially arranged so that light transmitted through any one holographic polymer dispersed liquid crystal element 40 enters the next holographic polymer dispersed liquid crystal element 40. Are lined up.

  Moreover, the illuminating device 10 shown by FIG. 1 has the object detection means 50 further. The application means 51 provided corresponding to each holographic polymer dispersed liquid crystal element 40 is controlled based on the detection result of the object detection means 50. The object detection means 50 has a function of detecting the object 99 corresponding to the installation purpose of the lighting device 10, for example. As an example, in the use of the lighting device 10 installed in a room, a hallway, a passage, or the like, a person existing in these places may be detected as the detection target 99. In this case, the object detection means 50 can use various known human sensors, for example, a sensor that detects a person based on a temperature distribution, or a sensor that detects a person by operation.

  Next, a specific method for controlling the light distribution of the illumination device 10 having the above configuration will be described.

  The illuminating device 10 shown by FIG. 1 is installed in a large sized room or a hallway, for example. Then, by controlling the light distribution of the illumination device 10, only the area that needs to be illuminated can be appropriately illuminated. In particular, in the illustrated example, a target detection unit 50 is provided, and the target detection unit 50 detects the position of the person 99. And the illuminating device 10 can illuminate only the peripheral area | region of the person 99 detected by the object detection means 50. FIG.

  In the example shown in FIG. 1, the object detection unit 50 detects that the object 99 exists on the second illuminated area Z2, that is, the person 99 exists on the second illuminated area Z2. Based on the detection result of the object detection means 50, the illumination device 10 sets the light distribution of the illumination light so as to illuminate only the second illuminated area Z2. Specifically, only the holographic polymer dispersed liquid crystal element 40 that constitutes the second optical element 22 that diffracts light toward the second illuminated region Z2 is set to the diffracted state. On the other hand, the holographic polymer dispersed liquid crystal element 40 that forms the first and third optical elements 21 and 23 that diffract light toward the first and third illuminated areas Z1 and Z3 is set in a transmission state. More specifically, a voltage is not applied to the holographic polymer dispersed liquid crystal element 40 that forms the second optical element 22, and the holographic polymer dispersed liquid crystal element 40 that forms the first and third optical elements 21 and 23. Apply voltage to only.

  In this state, when the light source device 15 projects light, the light passes through the first optical element 21 and enters the second optical element 22, and the holographic polymer dispersion type liquid crystal element forming the second optical element 22. Diffracted at 40. Here, when the diffraction efficiency in the holographic polymer dispersed liquid crystal element 40 constituting the second optical element 22 is not 100%, a part of the P wave is transmitted through the second optical element 22 and the third optical element is transmitted. Incident on the element 23. At this time, the holographic polymer dispersed liquid crystal element 40 forming the third optical element 23 is set in a transmissive state. Accordingly, the third illuminated area Z3 is not unintentionally illuminated brightly by the diffracted light from the holographic polymer dispersed liquid crystal element 40.

  Note that, from the viewpoint of utilization efficiency of light from the light source device 15, the light source device 15 generates only light of a specific linearly polarized light component corresponding to the P wave that is diffracted by the light distribution control tool 20. Is preferred. On the other hand, in preparation for the fact that the diffraction efficiency is not 100% and the transmission of the S wave, as shown by a two-dot chain line in FIG. 1, a light absorbing means 53 may be provided side by side with a plurality of optical elements. .

  In the first embodiment as described above, the lighting device 10 includes the light source device 15 and a light distribution controller including a plurality of optical elements 21, 22, and 23 that adjust the optical path of the light emitted from the light source device 15. 20. The light distribution controller 20 includes, as one or more optical elements, a holographic polymer dispersed liquid crystal element 40 that can switch between a state of diffracting light of a specific linearly polarized light component and a state of transmitting the light. Contains. The light diffracted by the holographic polymer dispersed liquid crystal element 40 illuminates an area at least partially different from the light emitted from the other optical elements. According to such an illuminating device 10, the light distribution of the illuminating device 10 can be controlled by switching the state of the holographic polymer dispersed liquid crystal element 40. Since this light distribution control does not include a machine or mechanism that operates at high speed, it can be stably realized with excellent reliability while paying sufficient attention to light safety.

  Further, in the first embodiment, a plurality of holographic polymer dispersed liquid crystal elements are arranged so that light emitted from the light source device 15 can sequentially pass through the plurality of holographic polymer dispersed liquid crystal elements 40. 40 are arranged. According to such a light distribution control tool 20, the light distribution of the illumination device 10 can be controlled by effectively using the light projected from the light source device 15.

  Various modifications can be made to the first embodiment. Hereinafter, an example of modification will be described with reference to the drawings as appropriate.

  In the first embodiment described above, an example in which the light distribution control tool 20 includes three optical elements has been described. However, the present invention is not limited to this example, and the light distribution control tool 20 includes two optical elements or four elements. The above optical elements may be included.

  In the first embodiment described above, the example in which the plurality of optical elements included in the light distribution control tool 20 are all formed by the holographic polymer dispersed liquid crystal element 40 has been described. However, the present invention is not limited to this example, and one or more optical elements included in the light distribution control tool 20 may be elements capable of adjusting an optical path other than the holographic polymer dispersed liquid crystal element. As an example, the one or more optical elements included in the light distribution control tool 20 may be a hologram recording medium such as a volume hologram or a relief hologram, a lens array, or the like. For example, when the second optical element 22 that illuminates the second illuminated area Z2 is composed of a hologram recording medium such as a volume hologram or a relief hologram, a lens array, or the like, whether or not a voltage is applied from the applying means 51. Regardless, the second illuminated area Z2 positioned between the first illuminated area Z1 and the third illuminated area Z3 can always be illuminated with some illuminance.

  Further, in the first embodiment described above, the example in which the target detection unit 50 detects the area where the target 99 to be detected exists and illuminates the area where the target 99 exists is shown. However, as shown in FIG. 5, the object detection unit 50 detects the moving direction of the object 99 together with the position of the object 99 and illuminates the area where the object 99 exists and the area ahead of the moving direction of the object 99. You may do it. In the example shown in FIG. 5, the person 99 that is the detection target is located in the second illuminated area Z2, and the person 99 is moving toward the third illuminated area Z3. In this example, the diffracted light from the second optical element 22 illuminates the second illuminated area Z2, and the diffracted light from the third optical element 23 illuminates the third illuminated area Z3.

  In the example illustrated in FIG. 5, the illumination device 10 further includes a polarization conversion element 52 that can be disposed between two adjacent holographic polymer dispersed liquid crystal elements 40. The polarization conversion element 52 is movable between a conversion position indicated by a solid line in FIG. 5 and a non-conversion position indicated by a two-dot chain line in FIG. The polarization conversion element 52 receives light transmitted through one holographic polymer dispersed liquid crystal element 40 on the side close to the light source device 15 at the conversion position. The polarization conversion element 52 arranged at the conversion position is on the side away from the light source device 15 for the polarization state of the light transmitted through the one holographic polymer dispersed liquid crystal element 40 on the side close to the light source device 15. Conversion to a polarization state that can be diffracted by the other holographic polymer dispersed liquid crystal element 40 is possible. On the other hand, the light transmitted through one holographic polymer dispersed liquid crystal element 40 does not enter the polarization conversion element 52 disposed at the non-converting position, and the other holographic height is maintained while maintaining the polarization state. The light enters the molecular dispersion type liquid crystal element 40.

  In the example shown in FIG. 5, the light source device 15 emits non-polarized light. The polarization conversion element 52 functions as a half-wave plate for linearly polarized light. In the state shown in FIG. 5, the P wave emitted from the light source device 15 passes through the first optical element 21 to which a voltage is applied, is diffracted by the second optical element 22 to which no voltage is applied, The illuminated area Z2 is illuminated. On the other hand, the S wave emitted from the light source device 15 passes through the first and second optical elements 21 and 22 and is then converted into a P wave by the polarization conversion element 52, and thereafter, the third optical element to which no voltage is applied. 23 illuminates the third illuminated area Z3. That is, by providing the polarization conversion element 52, the utilization efficiency of the light generated by the light source device 15 can be improved.

  Next, a second embodiment will be described with reference to FIGS. In the following description of the second embodiment and the drawings used in the description of the second embodiment, portions that can be configured in the same manner as in the first embodiment described above are described in the first embodiment described above. While using the same code | symbol as the code | symbol used with respect to the corresponding part in a form, the overlapping description is abbreviate | omitted.

  6 and 7 are side views schematically showing the illumination device 11. The light distribution of the illumination light from the illumination device 11 is different between the state shown in FIG. 6 and the state shown in FIG. On the other hand, FIG. 8 is a diagram showing the illumination device 11 from above, and shows the illumination device 11 together with the illuminated region irradiated with illumination light from the illumination device 11.

  The illumination device 11 includes a light source device 16 and a light distribution control tool 30 that controls the light distribution by adjusting the optical path of the light emitted from the light source device 16. The light distribution control tool 30 has a plurality of optical elements that can change the optical path of the light emitted from the light source device 16. In the example shown in the figure, the light distribution control tool 30 has first to fifth optical elements 31 to 35. Among these, the light source device 16 can be configured similarly to the light source device 15 described in the first embodiment. However, the light source device 16 of the second embodiment has a light emission surface 16a having a certain area corresponding to the configuration of the light distribution control tool 30 described later. That is, the light source device 16 is configured as a surface light source device, and emits a light beam from a planar area.

  The light distribution control tool 30 includes four holographic polymer dispersed liquid crystal elements 40 as the first to fourth optical elements 31 to 34, and includes a light diffusion element 48 as the fifth optical element. Yes. As shown in FIGS. 6 to 8, the plurality of optical elements 31 to 35 included in the light distribution control tool 30 are arranged at positions facing the light source device 16. A part of the light emitted from the light source device 16 enters each of the optical elements 31 to 35. In particular, in the illustrated example, the first to fifth optical elements 31 to 35 are arranged on one virtual plane located facing the light source device 16. Each of the first to fifth optical elements 31 to 35 occupies a portion obtained by plane-dividing a region having substantially the same area as the emission surface 16a of the light source device 16 without a gap. As a result, the light emitted from the light source device 16 enters one of the first to fifth optical elements 31 to 35.

  In the example shown in FIG. 8, the first to fifth optical elements 31 to 35 are spread over a rectangular area that is substantially the same as the planar view shape of the light source device 16. The first to fourth optical elements 31 to 34 are provided along a part of each side of the rectangular area, and the fifth optical element 35 occupies other areas in the rectangular area.

  The holographic polymer dispersed liquid crystal element 40 constituting the first to fourth optical elements 31 to 34 has the configuration and function described in the first embodiment. As an example, the holographic polymer dispersed liquid crystal element 40 constituting the first to fourth optical elements 31 to 34 can be manufactured by the manufacturing method described in the first embodiment. Although not shown, each holographic polymer dispersed liquid crystal element 40 is connected to the application means 51 described in the first embodiment. The application unit 51 is controlled based on the detection result of the target detection unit 50, as in the first embodiment.

  As shown in FIG. 8, the diffracted light Ld1 from the holographic polymer dispersed liquid crystal element 40 forming the first optical element 31 is irradiated to the first illuminated area Z1 to illuminate the area Z1. The diffracted light from the holographic polymer dispersed liquid crystal element 40 constituting the second optical element 32 is irradiated to the second illuminated area Z2 to illuminate the area Z2. The diffracted light from the holographic polymer dispersed liquid crystal element 40 constituting the third optical element 33 is irradiated to the third illuminated area Z3 to illuminate the area Z3. The diffracted light from the holographic polymer dispersed liquid crystal element 40 forming the fourth optical element 34 is irradiated onto the fourth illuminated area Z4 to illuminate the area Z4.

  On the other hand, the light diffusing element 48 constituting the fifth optical element 35 is constituted by, for example, a hologram recording medium such as a volume hologram or a relief hologram, a lens array, or the like. The diffused light Ld5 from the light diffusing element 48 forming the fifth optical element 35 is applied to the fifth illuminated area Z5 to illuminate the area Z5. In the example shown in FIGS. 6 to 8, the fifth illuminated area Z <b> 5 is located below the light distribution control tool 30. The fifth illuminated area Z5 is a rectangular area. When the light source device 16 irradiates the fifth optical element 35 with light, the fifth illuminated area Z5 is an area that is always illuminated, that is, an area that is illuminated regardless of conditions such as the presence or absence of voltage application. .

  In order to illuminate the fifth illuminated area Z5 with uniform illuminance, it is preferable that the light irradiated to each position or each small area of the fifth optical element 35 is diffused throughout the fifth illuminated area Z5. . Such a diffusing function of the fifth optical element 35 is, for example, a hologram recording medium that can reproduce an image of a scattering plate, more specifically, a volume hologram that records scattered light from the scattering plate as object light, or a uniform hologram. It can be ensured by a computer-generated hologram calculated so as to generate the diffused light Ld5.

  As shown in FIG. 8, each of the first to fourth illuminated areas Z1 to Z4 is an elongated area extending along each side of the fifth illuminated area Z5 that is a rectangular area. The fifth illuminated area Z5 partially overlaps the first to fourth illuminated areas Z1 to Z4 at the periphery. The first illuminated area Z1 partially overlaps the second illuminated area Z2 and the fourth illuminated area Z4 at both ends in the longitudinal direction. The second illuminated area Z2 partially overlaps the first illuminated area Z1 and the third illuminated area Z3 at both ends in the longitudinal direction. The third illuminated area Z3 partially overlaps the second illuminated area Z2 and the fourth illuminated area Z4 at both ends in the longitudinal direction. The fourth illuminated area Z4 partially overlaps the third illuminated area Z3 and the first illuminated area Z1 at both ends in the longitudinal direction.

  Next, a specific method for controlling the light distribution of the illumination device 11 having the above configuration will be described. 6 to 8 is installed in a space such as a large living room, for example. The lighting device 11 is installed above the central area of the installed space, for example, on the ceiling in the central area of the living room.

  The light emitted from the light source device 16 travels to the light distribution control tool 30 facing the emission surface 16 a of the light source device 16. That is, a part of the light emitted from the light source device 16 enters each of the first to fifth optical elements 35. The light incident on the light diffusing element 48 constituting the fifth optical element 35 is diffused and proceeds to the fifth illuminated area Z5 located below the light distribution control tool 30. That is, the diffused light Ld5 from the fifth optical element 35 is applied to the fifth illuminated area Z5 to illuminate the area Z5.

  In the state shown in FIG. 6, the object detection means 50 detects that the person 99 is present in the fifth illuminated area Z5. At this time, the holographic polymer dispersed liquid crystal element 40 constituting the first to fourth optical elements 31 to 34 is applied with a voltage and maintained in a transmissive state. Therefore, the light incident on the holographic polymer dispersed liquid crystal element 40 constituting the first to fourth optical elements 31 to 34 passes straight through the liquid crystal element 40 without being diffracted by the liquid crystal element 40. As shown in FIG. 6, the light transmitted through each holographic polymer dispersed liquid crystal element 40 is irradiated to a part of the fifth illuminated area Z5. As a result, the area below the illumination device 11, generally the center of the area where the illumination device 11 is installed, is illuminated brightly.

  On the other hand, in the state shown in FIGS. 7 and 8, the detection target 99 by the target detection means 50 has moved from the fifth illuminated area Z5 into the first illuminated area Z1. At this time, it is preferable to illuminate not only the fifth illuminated area Z5 but also the first illuminated area Z1. Therefore, the voltage application from the application unit 51 to the holographic polymer dispersed liquid crystal element 40 forming the first optical element 31 is stopped based on the detection result of the object detection unit 50. At this time, a voltage is still applied from the applying means 51 to the holographic polymer dispersed liquid crystal element 40 forming the second to fourth optical elements 32 to 34. As a result, as shown in FIGS. 7 and 8, the P wave incident on the first optical element 31 is diffracted by the first optical element 31 to illuminate the first illuminated region Z1. When the light source device 16 also emits an S wave, the S wave illuminates a part of the first illuminated area Z1 without being diffracted by the first optical element 31.

  In the example shown in FIGS. 7 and 8, the person 999 that is the detection target by the target detection unit 50 is already located in the first illuminated area Z1. However, the timing for starting the illumination of the first illuminated area Z1 may be when the person 99 in the fifth illuminated area Z5 starts moving toward the first illuminated area Z1.

  Also in the second embodiment as described above, the illumination device 11 includes a light source device 16 and a plurality of optical elements 31, 32, 33, and 34 that adjust the optical path of light emitted from the light source device 16. And a light controller 30. The light distribution controller 30 includes a holographic polymer dispersed liquid crystal element 40 that can switch between a state of diffracting light of a specific linearly polarized light component and a state of transmitting the light as one or more optical elements. Contains. The light diffracted by the holographic polymer dispersed liquid crystal element 40 illuminates an area at least partially different from the light emitted from the other optical elements. According to such an illuminating device 11, the light distribution of the illuminating device 11 can be controlled by switching the state of the holographic polymer dispersed liquid crystal element 40. Since such light distribution control does not include a machine or mechanism that operates at high speed, it can be stably realized with excellent reliability while paying sufficient attention to light safety.

  Further, in the second embodiment, the plurality of optical elements 31, 32, 33, and 34 are arranged so as to be positioned on the optical paths of some different lights emitted from the light source device 16. Therefore, since the light distribution control can be performed more directly and with a higher degree of freedom, the light distribution control can be realized more stably.

  Furthermore, in the second embodiment, the plurality of optical elements 31, 32, 33, and 34 are arranged on one plane to which the light from the light source device 16 is irradiated. Therefore, the arrangement space of the optical elements 31, 32, 33, and 34 included in the light distribution control tool 30 can be reduced.

  Furthermore, in the second embodiment, the light transmitted through the holographic polymer dispersed liquid crystal element 40 illuminates an area within the area illuminated by the light emitted from any other optical element. Therefore, it is possible to prevent the light transmitted through the liquid crystal element 40 without positively adjusting the optical path in the holographic polymer dispersed liquid crystal element 40 from adversely affecting the light distribution control.

  Various changes can be made to the second embodiment. Hereinafter, an example of modification will be described.

  In the second embodiment described above, an example in which the light distribution control tool 30 has four optical elements has been described. However, the present invention is not limited to this example, and there are two, three, or five light distribution control tools 30. The above optical elements may be included.

  In the second embodiment described above, the light distribution control is realized by the presence / absence of voltage application from the application means 51 to the holographic polymer dispersed liquid crystal element 40. However, the present invention is not limited to this example, and the light source device 16 includes a plurality of light sources that project light onto different optical elements 31 to 35, for example, a plurality of laser light sources, and the light emission timing of each light source is set. It may be possible to adjust independently. In this example, complex light distribution control can be stably realized by adjusting the light emission timing of each light source in addition to the presence or absence of voltage application by the application means 51.

  Furthermore, the following can be illustrated as a modification common to both the first embodiment and the second embodiment described above.

  In the first and second embodiments described above, the holographic polymer dispersed liquid crystal element 40 can be switched between a diffraction state and a transmission state depending on whether or not a voltage is applied. The diffraction efficiency of the holographic polymer dispersed liquid crystal element 40 may be controlled by further adjusting the magnitude of the applied voltage. According to such an example, the light distribution of the illumination device 10 can be controlled with a higher degree of freedom.

  Furthermore, in the first and second embodiments described above, the example in which the diffracted light from the holographic polymer dispersed liquid crystal element 40 reproduces the image of the scattering plate is shown, but the present invention is not limited to this example. The holographic polymer dispersed liquid crystal element 40 may reproduce an image having design properties, an image displaying information, or the like on the ground, floor, wall, or the like.

  The first and second embodiments described above and the modifications thereof have been described above, but naturally, a plurality of modifications may be appropriately combined and applied to the first or second embodiment. Is possible.

DESCRIPTION OF SYMBOLS 10 Illuminating device 11 Illuminating device 15 Light source device 16 Light source device 16a Exit surface 20 Light distribution control tool 21 1st optical element 22 2nd optical element 23 3rd optical element 30 Light distribution control tool 31 1st optical element 32 2nd optical element 33 third optical element 34 fourth optical element 35 fifth optical element 40 holographic polymer dispersed liquid crystal element 41 element layer 42 polymer layer 42a monomer 42b polymer chain 43 liquid crystal layer 44 liquid crystal molecule 48 light diffusing element 45 electrode layer 46 Base material 48 Light diffusing element 50 Target detecting means 51 Applying means 52 Polarization converting element 99 Target Z1 First illuminated area Z2 Second illuminated area Z3 Third illuminated area Z4 Fourth illuminated area Z5 Fifth illuminated area

Claims (3)

A light source device;
A light distribution controller including a plurality of optical elements for adjusting the optical path of the light emitted from the light source device,
The light distribution controller includes a holographic polymer dispersed liquid crystal element capable of switching between a state of diffracting light of a specific linearly polarized light component and a state of transmitting the light as one or more of the plurality of optical elements, Including
The light diffracted by the holographic polymer-dispersed liquid crystal element illuminates an area at least partially different from the light emitted from the other optical element ,
The light distribution controller includes a plurality of holographic polymer dispersed liquid crystal elements,
The light diffracted by the plurality of holographic polymer dispersed liquid crystal elements illuminates at least partially different areas,
The plurality of holographic polymer dispersed liquid crystal elements are arranged side by side so that light emitted from the light source device can sequentially pass through the plurality of holographic polymer dispersed liquid crystal elements,
A polarization conversion element that can be disposed between two adjacent holographic polymer dispersed liquid crystal elements;
The said polarization conversion element is an illuminating device which functions as a 1/2 wavelength plate with respect to the light of a linearly polarized light component . The lighting device according to claim 1 , wherein the light source device emits light of the specific linearly polarized light component. An object detection means capable of detecting an object to be detected;
The lighting device according to claim 1 or 2 , wherein switching of the state of the holographic polymer dispersed liquid crystal element is controlled based on a detection result of a target detection unit.

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