JP2007033576A - Illumination device and image display device, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination device capable of efficiently illuminating a prescribed surface while restraining the upsizing or the complication of the device or increase in device cost. <P>SOLUTION: The illumination device 1 is equipped with a diffraction optical element 4K generating diffracted light L2 by an incident laser beam L1 and illuminating a first surface 11 in a prescribed illumination area with the diffracted light L2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination device, an image display device, and a projector.

In a projection-type image display device (projector) that projects color light including image information generated by a spatial light modulation device such as a liquid crystal device on a screen using a projection system, a technique using a laser as a light source has been proposed.
Japanese Patent Laid-Open No. 11-64789 JP 2000-162548 A

  When a predetermined optical system is used to illuminate the incident surface of the spatial light modulator with a uniform illuminance distribution using laser light, the size and complexity of the device or the cost of the device may increase depending on the configuration of the optical system. there is a possibility. In addition, depending on the configuration of the optical system, there is a possibility that the light use efficiency and the like are reduced.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an illumination device that can efficiently illuminate a predetermined surface while suppressing an increase in size and complexity of the device or an increase in device cost. Another object of the present invention is to provide an image display device that displays an image using light illuminated by an illumination device, and a projector.

  In order to solve the above problems, the present invention adopts the following configuration.

  According to a first aspect of the present invention, a laser light source device that emits laser light, a laser light emitted from the laser light source device is incident, and diffracted light is generated by the incident laser light, An illuminating device including a diffractive optical element that illuminates a first surface with a diffracted light in a predetermined illumination area is provided.

  According to the present invention, it is possible to efficiently illuminate the first surface with high illuminance while suppressing an increase in size and complexity of the device or an increase in device cost.

  In the illumination device of the present invention, the diffractive optical element may employ a configuration in which the first surface is illuminated with a rectangular illumination area. Thereby, an illumination area | region can be illuminated efficiently.

  In the illuminating device of the present invention, the diffractive optical element may employ a configuration for making the illuminance uniform in the illumination region. Thereby, the illumination area can be illuminated in a desired state.

  In the illuminating device of the present invention, the diffractive optical element can employ a configuration in which the first surface is illuminated with an illumination area larger than an emission area where light is emitted from a light exit surface of the diffractive optical element. Thereby, the first surface is illuminated with the enlarged illumination area.

  In the illumination device of the present invention, it is possible to adopt a configuration in which the laser light emitted from the laser light source device is directly incident on the diffractive optical element. Thereby, while being able to suppress the number of parts of an illuminating device, light use efficiency can be improved.

  In the illumination device of the present invention, it is possible to employ a configuration in which a plurality of the laser light source devices are provided and a plurality of the diffractive optical elements are provided so as to correspond to the plurality of laser light source devices. Thereby, the first surface can be efficiently illuminated with high illuminance. Moreover, generation | occurrence | production of a speckle pattern can be suppressed and the 1st surface can be illuminated by substantially uniform illumination intensity distribution.

  In the illumination device of the present invention, a configuration in which a predetermined region on the first surface is illuminated in a superimposed manner with the diffracted light generated by each of the plurality of diffractive optical elements can be employed. Thereby, the first surface can be efficiently illuminated with high illuminance. Moreover, generation | occurrence | production of a speckle pattern can be suppressed and the 1st surface can be illuminated by substantially uniform illumination intensity distribution.

  In the illuminating device of the present invention, the plurality of laser light source devices may employ a configuration arranged in an array. Thereby, the first surface can be efficiently illuminated with high illuminance. Moreover, generation | occurrence | production of a speckle pattern can be suppressed and the 1st surface can be illuminated by substantially uniform illumination intensity distribution.

  In the illuminating device of the present invention, an angle adjusting optical element that is provided between the diffractive optical element and the first surface, is irradiated with light from the diffractive optical element, and adjusts an emission angle of the emitted light. It is possible to adopt a configuration including Thereby, the incident angle of the light with respect to the 1st surface can be adjusted, and the 1st surface can be illuminated efficiently.

  In the illuminating device of the present invention, the angle adjusting optical element can adopt a configuration including a refractive lens or a configuration including a diffractive optical element.

  The illuminating device of the present invention employs a configuration in which a substrate capable of transmitting light is provided, the diffractive optical element is provided on one surface of the substrate, and the angle adjusting optical element is provided on the other surface. be able to. Thereby, the number of parts of the lighting device can be suppressed and the first surface can be efficiently illuminated.

  In the illumination device of the present invention, the first surface can employ a configuration including image information. Thereby, an image can be displayed with the light which illuminated the 1st surface.

  According to a second aspect of the present invention, there is provided an image display device that is illuminated by the above-described illumination device and displays an image by light through the first surface.

  According to the present invention, it is possible to suppress an increase in size and complexity of an apparatus or an increase in apparatus cost, and to form a high-brightness and good image.

  In the image display device of the present invention, the first surface may include a light incident surface of a spatial light modulator that modulates the illuminated light in accordance with an image signal. The spatial light modulation device can employ a configuration including a liquid crystal device. Thereby, a desired image can be displayed.

  According to a third aspect of the present invention, there is provided a projector including the above-described image display device and including a projection system that projects light including image information via the first surface onto the second surface.

  According to the present invention, it is possible to suppress an increase in size and complexity of an apparatus or an increase in apparatus cost, and to form a high-brightness and good image.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, an XYZ orthogonal coordinate system is set as necessary, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system.

<First Embodiment>
A first embodiment will be described. FIG. 1 is a schematic configuration diagram illustrating an illumination device according to the first embodiment. In FIG. 1, an illuminating device 1 illuminates a first surface 11 of a predetermined member 10, and a laser light source device 2 that emits laser light L1 and a laser light L1 emitted from the laser light source device 2 are incident. In addition, a diffractive optical element 4K that generates diffracted light L2 by the incident laser light L1 and illuminates the first surface 11 with a predetermined illumination region with the diffracted light L2 is provided. The diffractive optical element 4K is supported by the support member 4B.

  An optical member is not provided between the laser light source device 1 and the diffractive optical element 4K, and the laser light L1 emitted from the laser light source device 2 is directly incident on the diffractive optical element 4K. It has become. The diffractive optical element 4K generates diffracted light L2 from the laser light L1 irradiated by the laser light source device 2, and illuminates the first surface 11 with a predetermined illumination region with the diffracted light L2. The diffracted light L2 generated by the diffractive optical element 4K is diffused light, and the diffractive optical element 4K illuminates the first surface 11 with the diffused light (diffracted light) L2 in a predetermined illumination area. Make the illuminance uniform. The diffractive optical element 4K illuminates the first surface 11 with an illumination area larger than the emission area where light is emitted from the light emission surface of the diffractive optical element 4K. That is, the diffractive optical element 4K is a so-called magnifying system (magnifying illumination system). In the present embodiment, the diffractive optical element 4K illuminates the first surface 11 with a rectangular illumination region.

  2A and 2B are schematic views showing an example of the diffractive optical element 4K. FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along line AA in FIG. The diffractive optical element shown in FIG. 2 has a plurality of rectangular recesses (uneven structure) 4M on its surface. The recesses 4M have different depths. In addition, the plurality of convex portions between the concave portions 4M have different heights. Then, by appropriately adjusting the surface condition of the diffractive optical element 4K including the pitch d between the concave parts 4M and the depth t (height of the convex part) of the concave parts 4M, the light irradiated on the diffractive optical element 4K is diffused. The size and shape of the illumination area can be set. In other words, the diffractive optical element 4K can have a predetermined function by optimizing the surface conditions including the pitch d between the recesses 4M and the depth t of the recesses 4M. When the values of the pitch d between the recesses 4M and the depth t of the recesses 4M are made different for each of a plurality of regions on the surface of the diffractive optical element 4K, the surface conditions of the diffractive optical element 4K are formed. The distribution of the pitch d between the recesses 4M and the distribution of the depth t of the recesses 4M are also included. As a design method for optimizing the surface condition including the pitch d of the recesses 4M and the depth t of the recesses 4M, a predetermined calculation method (simulation method) such as an iterative Fourier method is exemplified. Then, by optimizing the surface conditions of the diffractive optical element 4K, the diffractive optical element 4K having a desired function can be formed.

  The diffractive optical element 4K is not limited to the one having the rectangular recess 4M, and may be a diffractive optical element having a surface in which planes facing different directions are combined. For example, the diffractive optical element 4K may have a triangular recess having a slope as shown in FIG. Further, the diffractive optical element 4K may have a region having a rectangular recess as shown in FIG. 2 and a region having a triangular recess as shown in FIG. . Then, by optimizing the surface conditions, the diffractive optical element 4K having a desired function can be formed.

  Here, an example of a manufacturing method of the diffractive optical element 4K will be described with reference to FIG. As shown in FIG. 4A, after a resist is coated on a quartz substrate, the resist is patterned by irradiating the resist with an electron beam by an electron beam drawing apparatus. Next, by performing an etching process, a mold made of quartz is formed as shown in FIG. And the board | substrate and mold for forming a diffractive optical element, such as a synthetic resin film-like member, are heated more than the glass transition temperature of a board | substrate. Then, as shown in FIG. 4C, the substrate and the mold are pressed and held for a certain period of time. Thereafter, the substrate and the mold are cooled below the glass transition temperature of the substrate, and the substrate and the mold are separated. As a result, as shown in FIG. 4D, a synthetic resin-made diffractive optical element having a desired shape is formed. Thus, in this embodiment, after forming a mold (mold), the diffractive optical element is formed by a so-called nanoimprint technique in which the shape of the mold is thermally transferred to the substrate.

  Note that the method of manufacturing a diffractive optical element described here is an example, and any method can be used as long as a diffractive optical element having a desired shape can be manufactured.

  FIG. 5 is a schematic diagram showing the first surface 11 illuminated by the illumination device 1 including the diffractive optical element 4K. As shown in FIG. 5, the illumination device 1 including the diffractive optical element 4 </ b> K can set an illumination area LA on the first surface 11. Specifically, the illumination device 1 including the diffractive optical element 4K can set at least one of the size and shape of the illumination area LA on the first surface 11. In the present embodiment, the illumination device 1 including the diffractive optical element 4K sets the illumination area LA to a rectangular shape (rectangular shape). A first surface (including an incident surface of a light valve to be described later) 11 in the present embodiment is rectangular, and the illumination device 1 including the diffractive optical element 4K sets an illumination area LA corresponding to the first surface 11. The size and shape of the illumination area LA can be set by appropriately adjusting the surface conditions of the diffractive optical element 4K (such as the pitch d between the recesses 4M and the depth t of the recesses 4M). In other words, by optimizing the surface conditions including the pitch d between the recesses 4M and the depth t of the recesses 4M, the diffractive optical element 4K can have a function as an illumination area setting optical system. Further, by optimizing the surface conditions of the diffractive optical element 4K, diffused light that can make the illuminance in the illumination area LA uniform can be generated, and light is emitted from the light exit surface of the diffractive optical element 4K. The first surface 11 can be illuminated with an illumination area LA that is larger than the emission area. Then, by optimizing the surface condition of the diffractive optical element 4K using a predetermined method such as the above-described iterative Fourier method, a desired function (an illumination area setting function, a diffused light generation function, an enlarged illumination function, etc.) is provided. The diffractive optical element 4K can be formed.

  That is, the diffractive optical element 4K of the present embodiment has each of an illumination area setting function, a diffused light generation function (illuminance uniformity function), and an enlarged illumination function, and the recess 4M so as to have these functions. The surface conditions including the pitch d and the depth t of the recess 4M are optimized.

  In the present embodiment, the diffractive optical element 4K has the illumination area LA set in a rectangular shape. However, by optimizing the surface conditions including the pitch d between the recesses 4M and the depth t of the recesses 4M, For example, the illumination area LA can be set to an arbitrary shape such as a line shape or a circular shape.

  FIG. 6 is a schematic configuration diagram illustrating an image display device including the illumination device 1 (1R, 1G, 1B) according to the present embodiment. In the present embodiment, a projection type image display device (projector) that projects color light including image information generated by a spatial light modulator on a screen via a projection system will be described as an example of the image display device.

  In FIG. 6, the projection type image display device PJ includes a projection unit U that projects light including image information on a screen 100 (second surface). An image is formed on the screen 100 by projecting light from the projection unit U onto the screen 100. The image display device PJ according to the present embodiment uses the screen 100 as a transmissive screen, and projects light including image information onto the screen 100 from the front side of the screen 100.

  The projection unit U includes a first illumination device 1R that can illuminate the first surface with the first basic color light (red light), and a second illumination device that can illuminate the first surface with the second basic color light (green light). 1G, a third illuminating device 1B capable of illuminating the first surface with the third basic color light (blue light), and an incident surface (first surface) 11 illuminated by the first illuminating device 1R. The first spatial light modulation device 10R that modulates light according to image information and the incident surface (first surface) 11 illuminated by the second illumination device 1G, and the illuminated light according to image information And a second spatial light modulation device 10G that modulates light and an incident surface (first surface) 11 that is illuminated by the third illumination device 1B and that modulates the illuminated light in accordance with image information. A color synthesizing system 12 that synthesizes the basic color light modulated by the light modulation device 10B and the spatial light modulation devices 10R, 10G, and 10B. The light generated by the color synthesizing system 12 and a projection system 13 for projecting on the screen 100. Each of the spatial light modulation devices 10R, 10G, and 10B includes a liquid crystal device. In the following description, the spatial light modulator is appropriately referred to as a light valve.

  The light valve includes an incident-side polarizing plate, a panel having a liquid crystal sealed between a pair of glass substrates, and an emission-side polarizing plate. A pixel electrode and an alignment film are provided on the glass substrate. The light valve constituting the spatial light modulator transmits only light in a predetermined vibration direction, and the basic color light incident on the light valve is light-modulated by passing through the light valve.

  The laser light source device 2 of the first illumination device 1R emits red (R) laser light. The first illumination device 1R generates diffracted light that illuminates a desired region from the red laser light by the diffractive optical element 4K, and illuminates the incident surface 11 of the first light valve 10R with the generated diffracted light.

  The laser light source device 2 of the second illumination device 1G emits green (G) laser light. The second illumination device 1G generates diffracted light that illuminates a desired region from the green laser light by the diffractive optical element 4K, and illuminates the incident surface 11 of the second light valve 10G with the generated diffracted light.

  The laser light source device 2 of the third illumination device 1B emits blue (B) laser light. The third illumination device 1B generates diffracted light that illuminates a desired region from the blue laser light by the diffractive optical element 4K, and illuminates the incident surface 11 of the third light valve 10B with the generated diffracted light.

  Each basic color light (modulated light) modulated by passing through each light valve 10R, 10G, 10B is synthesized by the color synthesis system 12. The color synthesis system 12 is configured by a dichroic prism, and the red light (R), the green light (G), and the blue light (B) are synthesized by the color synthesis system 12 and become full-color synthesized light. Full-color synthesized light emitted from the color synthesis system 12 is supplied to the projection system 13. The projection system 13 projects full-color synthesized light on the screen 100. The projection system 13 is a so-called enlargement system that enlarges an image on the incident side and projects it on the screen 100.

  The projection unit U projects full-color composite light including image information via the light valves 10R, 10G, and 10B illuminated by the lighting devices 1R, 1G, and 1B onto the screen 100 using the projection system 13. As a result, a full-color image is formed on the screen 100. The viewer appreciates the image projected on the screen 100 by the projection unit U.

  As described above, according to the illuminating device 1 of the present embodiment, an increase in size and complexity of the device or an increase in device cost is suppressed, and the first surface (light valve incident surface) 11 is distributed with a uniform illuminance distribution. It can be illuminated efficiently. That is, when an optical system such as a rod integrator or a fly-eye lens is used to illuminate the first surface with a uniform illuminance distribution using laser light emitted from a laser light source device, the number of parts increases or optical There is a possibility that the system will be complicated and the whole apparatus will be enlarged and complicated. Moreover, there is a possibility that the cost of the apparatus is increased due to an increase in the number of parts and the use of expensive parts such as a rod integrator. Furthermore, there is a risk that light utilization efficiency and the like will be reduced, such as Fresnel reflection loss generated from the interface of each optical element. In the present embodiment, since relatively inexpensive optical elements are used and the number of parts is reduced, the first surface 11 can be efficiently illuminated by suppressing an increase in size and complexity of the device or an increase in device cost. be able to.

  Further, since the diffractive optical element 4K can set the illumination area LA on the first surface 11, the illumination area LA can be efficiently illuminated. That is, when the 1st surface 11 is illuminated with the light via a lens etc., the situation where the shape of the illumination area LA and the shape of the 1st surface 11 differ may arise. That is, for example, the first surface 11 is rectangular, but the illumination area LA when the first surface 11 is illuminated through a lens may be circular. In this case, in order to illuminate the first surface 11 while suppressing light leakage, it is necessary to enlarge the circular illumination area LA and shape the illumination area LA using a light shielding member or the like. In this case, the light utilization efficiency decreases. In the present embodiment, by setting the illumination area LA using the diffractive optical element 4K, almost all of the light generated by the diffractive optical element 4K can be irradiated onto the first surface 11, and the light use efficiency is improved. be able to.

  Further, since a laser light source device is used as a light source, polarized light can be emitted, and compared with a configuration using a white light source such as an ultra-high pressure mercury lamp as a light source, a polarization separation element (polarization beam splitter) In addition, components such as a color separation element (dichroic mirror) can be omitted. Further, since laser light (basic color light) in a narrow wavelength band is emitted, good color reproducibility can be obtained when an image is displayed using the laser light. In addition, since the liquid crystal device (light valve) is not irradiated with ultraviolet light, deterioration of the light valve can be suppressed.

  Further, as described with reference to FIG. 4 and the like, since the diffractive optical element 4K can be manufactured by the nanoimprint technique, the diffractive optical element can be easily manufactured in large quantities, and the manufacturing cost can be reduced. Can do.

Second Embodiment
A second embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  7A and 7B are diagrams showing the lighting device 1 according to the second embodiment, in which FIG. 7A is a side view and FIG. 7B is a perspective view. In FIG. 7, the illumination device 1 includes a plurality of laser light source devices 2. The plurality of laser light source devices 2 are arranged in an array, and in the present embodiment, a plurality of laser light source devices 2 are provided side by side in the one-dimensional direction (X direction). The light emission surface of the laser light source device 2 faces the + Z side, and each laser light source device 2 emits the laser light L1 in the + Z direction.

  A plurality of diffractive optical elements 4K are provided so as to correspond to the plurality of laser light source devices 2, respectively. In the example shown in FIG. 7, a plurality of laser light source devices 2 are provided side by side in the one-dimensional direction (X-axis direction), and the diffractive optical element 4K corresponds to the plurality of laser light source devices 2. A plurality of elements are provided side by side in the one-dimensional direction (X-axis direction) on the support member 4B. Each of the plurality of diffractive optical elements 4K is optimized according to the position and characteristics of the plurality of laser light source devices 2.

  Further, each diffractive optical element 4K can set the illumination area to a rectangular shape as in the above-described embodiment.

  The laser light L1 emitted from each laser light source device 2 is converted into diffracted light L2 that illuminates a desired region by each diffractive optical element 4K, and then illuminated onto the first surface 11.

  As described above, a plurality of light emission surfaces of the laser light source device 2 may be arranged in an array. By doing so, the amount of light can be increased, and the first surface 11 can be illuminated with high illuminance. The illumination device 1 illuminates the first surface (including the incident surface of the light valve) 11 including the image information, so that the image display device PJ can display a high-luminance image.

  In addition, since the plurality of laser light source devices 2 are provided, the amount of light (illuminance) on the first surface 11 can be increased. Then, by displaying an image with light through the first surface (light valve incident surface) 11 illuminated by the illumination device 1, it is possible to realize high brightness and high contrast of the image.

  Moreover, in this embodiment, since the illuminating device 1 is provided with the several laser light source device 2, generation | occurrence | production of a speckle pattern can also be suppressed. A speckle pattern is a speckle pattern with high contrast that occurs in space when a scattered surface (diffuse light) is observed by irradiating a scattering surface containing a rough surface or an inhomogeneous medium with coherent light such as laser light. Say a pattern. Scattered light (diffused light) generated at each point on the scattering surface interferes with each other in a random phase relationship, resulting in a complicated interference pattern, which may illuminate the first surface 11 with a non-uniform illumination distribution. is there. In the present embodiment, the illumination device 1 includes a plurality of laser light source devices 2 and the laser beams emitted from the plurality of laser light source devices 2 are incoherent with each other. The first surface 11 is illuminated with light having Therefore, by superimposing the diffused light based on each laser beam on the first surface 11, the apparent speckle pattern can be reduced and the illuminance distribution on the first surface 11 can be made substantially uniform. Therefore, the image display device PJ can display an image with small luminance unevenness (illuminance unevenness).

<Third Embodiment>
A third embodiment will be described. FIGS. 8A and 8B are diagrams showing the lighting device 1 according to the third embodiment, in which FIG. 8A is a side view and FIG. 8B is a perspective view. In FIG. 8, the illumination device 1 includes a plurality of laser light source devices 2. The plurality of laser light source devices 2 are arranged in an array, and in the present embodiment, a plurality of laser light source devices 2 are provided side by side in the one-dimensional direction (X direction). The light emission surface of the laser light source device 2 faces the + Z side, and each laser light source device 2 emits the laser light L1 in the + Z direction.

  A plurality of diffractive optical elements 4K are provided so as to correspond to the plurality of laser light source devices 2, respectively. In the example shown in FIG. 8, a plurality of laser light source devices 2 are provided side by side in the one-dimensional direction (X-axis direction), and the diffractive optical element 4K corresponds to the plurality of laser light source devices 2. A plurality of elements are provided side by side in the one-dimensional direction (X-axis direction) on the support member 4B. Each of the plurality of diffractive optical elements 4K is optimized according to the position and characteristics of the plurality of laser light source devices 2.

  Each of the plurality of diffractive optical elements 4K can illuminate a predetermined region on the first surface 11 in a superimposed manner with the diffracted light L2 generated based on the laser light L1 emitted from each of the plurality of laser light source devices 2. In addition, the surface conditions (including the pitch between the recesses and the depth of the recesses) are optimized. As a design technique for optimizing the surface condition of each of the diffractive optical elements 3K, a predetermined calculation technique such as the above-described iterative Fourier method may be mentioned.

  Further, each diffractive optical element 4K can set the illumination area to a rectangular shape as in the above-described embodiment.

  Laser light L1 emitted from each laser light source device 2 is converted into diffracted light L2 that illuminates a desired region by each optical element 4K, and then is illuminated onto the first surface 11.

  In this manner, the predetermined region on the first surface 11 can be illuminated in a superimposed manner with the diffracted light L2 generated by each of the plurality of diffractive optical elements 4K. Thereby, the 1st surface 11 can be efficiently illuminated with high illumination intensity. Moreover, generation | occurrence | production of a speckle pattern can be suppressed and the 1st surface 11 can be illuminated by substantially uniform illumination intensity distribution.

<Fourth embodiment>
A fourth embodiment will be described with reference to FIG. 9A and 9B are diagrams showing the lighting device 1 according to the fourth embodiment, in which FIG. 9A is a side view and FIG. 9B is a perspective view. The characteristic part of this embodiment is that the light from the diffractive optical element 4K is irradiated between the diffractive optical element 4K and the first surface 11, and the angle adjusting optical for adjusting the emission angle of the emitted light. The element 5 is provided.

  In FIG. 9, the illumination device 1 includes a plurality of laser light source devices 2. The plurality of laser light source devices 2 are arranged in an array, and in the present embodiment, a plurality of laser light source devices 2 are provided side by side in the one-dimensional direction (X direction). The light emission surface of the laser light source device 2 faces the + Z side, and each laser light source device 2 emits the laser light L1 in the + Z direction.

  A plurality of diffractive optical elements 4K are provided so as to correspond to the plurality of laser light source devices 2, respectively. In the example shown in FIG. 9, a plurality of laser light source devices 2 are provided side by side in a one-dimensional direction (X-axis direction), and the diffractive optical element 4K corresponds to the plurality of laser light source devices 2. A plurality of elements are provided side by side in the one-dimensional direction (X-axis direction) on the support member 4B. Each of the plurality of diffractive optical elements 4K is optimized according to the position and characteristics of the plurality of laser light source devices 2.

  Further, each diffractive optical element 4K can set the illumination area to a rectangular shape as in the above-described embodiment.

  The laser light L1 emitted from each laser light source device 2 is converted into diffracted light L2 that illuminates a desired region by each optical element 4K, and then enters the angle adjusting optical element 5.

  The angle adjusting optical element 5 is composed of a refractive lens (field lens). The refractive lens includes, for example, an axial target lens that is rotationally symmetric with respect to the optical axis, such as a spherical lens or an aspheric lens, a Fresnel lens, and the like. The angle adjusting optical element 5 can adjust the emission angle of light emitted from each of the diffractive optical elements 4K. In the present embodiment, the angle adjusting optical element 5 emits light to be emitted so as to illuminate a predetermined region on the first surface 11 with the diffracted light L2 from each of the plurality of diffractive optical elements 4K. Optimized to adjust the angle.

  Thus, by providing the angle adjusting optical element 5, the incident angle of light with respect to the first surface 11 can be reduced, and the incident angle of light with respect to the first surface 11 can be made uniform in the surface. Therefore, the first surface 11 can be efficiently illuminated. And the predetermined area | region on the 1st surface 11 can be illuminated in a superimposed manner with the diffracted light L2 produced | generated by each of several diffractive optical element 4K. Thereby, the 1st surface 11 can be efficiently illuminated with high illumination intensity. Moreover, generation | occurrence | production of a speckle pattern can be suppressed and the 1st surface 11 can be illuminated by substantially uniform illumination intensity distribution.

  The angle adjusting optical element 5 may be an optical element having a plurality of different lens surfaces 5A provided so as to correspond to each of the plurality of laser light source devices 2, as shown in FIG.

  A plurality of optical elements including the above-described refractive lens may be arranged side by side in the light path direction (Z-axis direction in the drawing).

  In the second to fourth embodiments, a plurality of laser light source devices 2 are provided side by side in the one-dimensional direction (X-axis direction), but a plurality of laser light source devices 2 are provided side by side in the two-dimensional direction (XY direction). May be.

<Fifth Embodiment>
A fifth embodiment will be described with reference to FIG. FIG. 11 is a diagram showing the lighting device 1 according to the fourth embodiment. A characteristic part of the present embodiment is that a diffractive optical element 5K is provided as the angle adjusting optical element 5 between the diffractive optical element 4K and the first surface 11.

  In FIG. 11, the illuminating device 1 is provided between the diffractive optical element 4K irradiated with the laser light L1 from the laser light source device 2, and between the diffractive optical element 4K and the first surface 11, and from the diffractive optical element 4K. A second diffractive optical element 5K that adjusts the emission angle of the emitted light while being irradiated with light is provided. The diffractive optical element 4K can set the illumination area to a rectangular shape as in the above-described embodiment. Therefore, the diffractive optical element 4K illuminates the second diffractive optical element 5K with a rectangular illumination region. The second diffractive optical element 5 </ b> K can adjust the emission angle of the emitted light, and hence the incident angle of the light with respect to the first surface 11. The second diffractive optical element 5K of the present embodiment includes a Fresnel lens.

  Moreover, in this embodiment, the illuminating device 1 is provided with the board | substrate 6 which can permeate | transmit light, and the diffractive optical element 4K is provided in the surface close | similar to the laser light source device 2 among the board | substrates 6, and is 2nd diffraction. The optical element 5K is provided on a surface close to the first surface 11. The substrate 6 is made of, for example, a transparent synthetic resin film member or a glass plate member such as quartz.

  In this manner, the angle adjusting optical element 5 can be constituted by the diffractive optical element 5K. Further, it is possible to provide the diffractive optical element 4K for setting the shape of the illumination region on one surface of the substrate 6 that can transmit light, and the second diffractive optical element 5K for adjusting the light emission angle on the other surface. By doing so, it is possible to efficiently illuminate the first surface 11 while suppressing the number of parts of the illumination device 1.

  In the fifth embodiment, the diffractive optical element 4K and the second diffractive optical element 5K may be provided separately without providing the substrate 6.

  In the fifth embodiment, the diffractive optical element 4K may be provided on one surface of the substrate 6, and a refractive lens or the like may be provided as an angle adjusting optical element on the other surface.

  As the angle adjusting optical element 5, the refractive lens described in the fourth embodiment and the diffractive optical element described in the fifth embodiment may be combined.

  In the first to fifth embodiments described above, among the transmission type diffractive optical elements, the phase modulation type diffractive optical element is used as the diffractive optical element, but the amplitude modulation type diffractive optical element is used. You can also. Further, the invention is not limited to the transmission type diffractive optical element, and a reflection type diffractive optical element can also be used. Further, for example, a transmissive diffractive optical element and a reflective diffractive optical element may be combined. Then, by optimizing the surface conditions of these diffractive optical elements, the diffractive optical elements can have a desired function.

  In each of the above-described embodiments, a transmissive liquid crystal device (light valve) is used as the spatial light modulator, but a reflective liquid crystal device can also be used, for example, a DMD (Digital Micromirror Device) or the like. A reflective light modulator (mirror modulator) may be used.

  In each of the above-described embodiments, the front projection type projector that projects light including image information onto the screen 100 from the front side of the screen 100 has been described as an example. However, the projection unit U, the screen 100, and the housing are described. And the projection unit U is disposed on the back side of the screen 100, and the so-called rear projector that projects light including image information from the back side of the screen 100 onto the screen 100. 1 can also be applied.

  In addition, the projector PJ of the above-described embodiment includes the first, second, and third illumination devices 1R, 1G, and 1B each having the laser light source device 2 that can emit each basic color light (R, G, and B). However, a red laser light source device that emits red light (R), a green laser light source device that emits green light (G), and a blue laser light source device that emits blue light (B) are arranged in an array. The structure which has one illuminating device which has these may be sufficient. In this case, the laser light emission operation of the laser light source device capable of emitting each basic color light is performed in a time-sharing manner, and the operation of the light valve is controlled in synchronization with the laser light emission operation of each laser light source device. A full color image can be displayed on the screen 100 with one lighting device and one light valve.

<Sixth Embodiment>
In each of the above-described embodiments, the illumination device 1 illuminates the spatial light modulation device, and an image is displayed on the screen 100 by light passing through the spatial light modulation device. However, the image display device (projector) is used. For example, the spatial light modulator may not be provided. For example, as shown in FIG. 12, a so-called slide projector that illuminates a surface 11 ′ of a slide (positive film) 10 ′ including image information with a lighting device 1 and projects light including image information on a screen 100 is described above. It is also possible to apply the illumination device 1 of each of the embodiments.

  The image display device may be a direct-view image display device that does not have a projection system and directly observes the image of the spatial light modulation device.

It is a perspective view which shows schematic structure of the illuminating device which concerns on 1st Embodiment. It is a schematic diagram for demonstrating an example of a diffractive optical element. It is a schematic diagram for demonstrating an example of a diffractive optical element. It is a schematic diagram for demonstrating an example of the manufacturing method of a diffractive optical element. It is a figure which shows the 1st surface illuminated with the illuminating device. It is a schematic block diagram which shows the image display apparatus provided with the illuminating device which concerns on 1st Embodiment. It is a figure which shows schematic structure of the illuminating device which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the illuminating device which concerns on 3rd Embodiment. It is a figure which shows schematic structure of the illuminating device which concerns on 4th Embodiment. It is a figure which shows schematic structure of the illuminating device which concerns on 4th Embodiment. It is a figure which shows schematic structure of the illuminating device which concerns on 5th Embodiment. It is a figure which shows schematic structure of the image display apparatus which concerns on 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 2 ... Laser light source device, 4K ... Diffractive optical element, 5 ... Optical element for angle adjustment, 6 ... Substrate, 10 ... Spatial light modulator, 11 ... 1st surface (incident surface), 100 ... Screen ( Second surface), LA ... illumination area, PJ ... image display device (projector)

Claims (11)

A laser light source device for emitting laser light;
A diffractive optical element that emits laser light emitted from the laser light source device, generates diffracted light by the incident laser light, and illuminates the first surface with a predetermined illumination region with the diffracted light; Provided lighting device.   The illumination device according to claim 1, wherein the diffractive optical element illuminates the first surface with a rectangular illumination region.   The illumination device according to claim 1, wherein the diffractive optical element makes the illuminance uniform in the illumination area.   4. The illumination device according to claim 1, wherein the diffractive optical element illuminates the first surface with an illumination area larger than an emission area where light is emitted from a light emission surface of the diffractive optical element.   The illumination device according to any one of claims 1 to 4, wherein the laser light emitted from the laser light source device is directly incident on the diffractive optical element. A plurality of the laser light source devices;
The illuminating device according to claim 1, wherein a plurality of the diffractive optical elements are provided so as to correspond to the plurality of laser light source devices.   2. An angle adjusting optical element that is provided between the diffractive optical element and the first surface and is irradiated with light from the diffractive optical element and adjusts an emission angle of the emitted light. The lighting device according to claim 6. It has a substrate that can pass light,
The illumination device according to claim 7, wherein the diffractive optical element is provided on one surface of the substrate, and the angle adjusting optical element is provided on the other surface.   An image display device that is illuminated by the illumination device according to any one of claims 1 to 8 and that displays an image using light through the first surface.   The image display device according to claim 9, wherein the first surface includes an incident surface of a spatial light modulator that modulates the illuminated light in accordance with an image signal. 11. A projector comprising the image display device according to claim 9 or 10, wherein the projector includes a projection system that projects light including image information via the first surface onto the second surface.

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