JP4449848B2 - LIGHTING DEVICE, IMAGE DISPLAY DEVICE, AND PROJECTOR - Google Patents

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

  In a projector, in order to obtain a desired image, it is important to illuminate the incident surface of the spatial light modulator with a uniform illuminance distribution with a laser beam. Therefore, it is important to construct an optical system for illuminating the incident surface of the spatial light modulator with a uniform illuminance distribution using laser light.

  This invention is made | formed in view of the said situation, and it aims at providing the illuminating device which can illuminate a predetermined surface in a desired state. 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 and a laser light emitted from the laser light source device are incident, and diffused light is generated by diffusing the incident laser light. There is provided an illuminating device including: a diffusing optical element that diffracts light; and a diffractive optical element that generates diffracted light using diffused light from the diffused optical element and illuminates a first surface with the diffracted light.

  According to the present invention, since the first surface is illuminated with the diffracted light generated from the diffused light, even if the zero-order light is generated from the diffractive optical element, the zero-order light on the first surface is generated. An increase in local illuminance (luminance) can be suppressed. Therefore, the first surface can be illuminated in a desired state.

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

  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 diffusing optical element may employ a configuration including a scattering member that scatters irradiated light. The scattering member can employ a configuration including a base material that transmits light and fine particles on the base material, and the scattering member can also include a configuration including an optical member having a rough surface. . Alternatively, the diffusing optical element can employ a configuration including a diffractive optical element.

  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 may include a refractive lens. Alternatively, the angle adjusting optical element may include a diffractive optical element.

  In the illumination device of the present invention, it is possible to employ a configuration in which a substrate capable of transmitting light is provided, the diffusion optical element is provided on one surface of the substrate, and the diffractive optical element is provided on the other surface. it can. 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, it is possible to adopt a configuration in which a plurality of the laser light source devices are provided and the plurality of laser light source devices are 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 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.

  ADVANTAGE OF THE INVENTION According to this invention, a desired image can be obtained with the light via the 1st surface illuminated in the desired state.

  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 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 is emitted from each of a plurality of laser light source devices 2 that emit laser light L1 and a plurality of laser light source devices 2. The diffused optical element 4 that diffuses the incident laser light L1 to generate the diffused light L2 and the diffracted light L3 from the diffused light L2 from the diffused optical element 4 are generated. And a diffractive optical element 5 that illuminates the first surface 11 with diffracted light L3. Between the diffractive optical element 5 and the first surface 11, there is provided an angle adjusting optical element 6 for irradiating the light from the diffractive optical element 5 and adjusting the emission angle of the emitted light. The optical element 5 irradiates the first surface 11 with the generated diffracted light L3 via the angle adjusting optical element 6.

  The plurality of laser light source devices 2 are arranged in an array. In the example shown in FIG. 1, a plurality of laser light source devices 2 are provided side by side in a one-dimensional direction (X-axis 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.

  The diffusing optical element 4 diffuses the laser light L1 from the laser light source device 2 to generate diffused light L2. In the present embodiment, the diffusing optical element 4 includes a scattering member that scatters the irradiated light.

  FIG. 2 is a view showing an example of the scattering member (diffusing optical element) 4. The scattering member 4 includes a base material 4A that transmits light and fine particles 4B on the base material 4A. The base material 4A that transmits light is made of, for example, a transparent synthetic resin film-like member or a glass plate-like member such as quartz. A plurality of fine particles 4B having different refractive indexes are bonded to the base material 4A via a binder 4C. The light applied to the scattering member 4 is converted into diffused light (scattered light) L2 by passing through the scattering member 4.

  FIG. 3 is a view showing another example of the scattering member (diffusing optical element) 4. The scattering member 4 is configured by an optical member 4D having a rough surface. The optical member 4D is made of a plate member made of glass such as quartz that can transmit light. The light applied to the scattering member 4 is converted into diffused light (scattered light) L2 by passing through the scattering member 4.

  Returning to FIG. 1, the diffractive optical element 5 generates diffracted light L3 from the diffused light L2 from the diffused optical element 4, and illuminates the first surface 11 via the angle adjusting optical element 6 with the diffracted light L3. Is. In the present embodiment, the diffractive optical element 5 illuminates the first surface 11 with a predetermined illumination area with the diffracted light L3. The diffracted light L3 generated by the diffractive optical element 5 is light diffused so as to illuminate a predetermined area, and the diffractive optical element 5 illuminates the first surface 11 with the diffracted light L3 with a predetermined illumination area. Then, the illuminance in the illumination area is made uniform. The diffractive optical element 5 can illuminate the predetermined surface (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 5. That is, the diffractive optical element 5 is a so-called magnifying system (magnifying illumination system). In the present embodiment, the diffractive optical element 5 illuminates the first surface 11 with a rectangular illumination area.

  4A and 4B are schematic views showing an example of the diffractive optical element 5. FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along line AA in FIG. The diffractive optical element shown in FIG. 4 has a plurality of rectangular recesses (uneven structure) 5M on its surface. The recesses 5M have different depths. The plurality of convex portions between the concave portions 5M also have different heights. Then, by appropriately adjusting the surface condition of the diffractive optical element 5 including the pitch d between the concave parts 5M and the depth t (the height of the convex part) of the concave parts 5M, the light irradiated on the diffractive optical element 5 is diffused. The size and shape of the illumination area can be set. In other words, the diffractive optical element 5 can have a predetermined function by optimizing the surface conditions including the pitch d of the recesses 5M and the depth t of the recesses 5M. When the values of the pitch d between the recesses 5M and the depth t of the recesses 5M are made different for each of a plurality of regions on the surface of the diffractive optical element 5, the surface conditions of the diffractive optical element 5 are formed. The distribution of the pitch d between the recesses 5M and the distribution of the depth t of the recesses 5M are also included. As a design method for optimizing the surface condition including the pitch d of the recesses 5M and the depth t of the recesses 5M, for example, a predetermined calculation method (simulation method) such as an iterative Fourier method may be mentioned. Then, by optimizing the surface conditions of the diffractive optical element 5, it is possible to form the diffractive optical element 5 having a desired function.

  The diffractive optical element 5 is not limited to the one having the rectangular recess 5M, and may be a diffraction grating having a surface in which planes facing different directions are combined. For example, the diffractive optical element 5 may have a triangular recess having a slope as shown in FIG. Moreover, the diffractive optical element 5 may have each of a region having a rectangular recess as shown in FIG. 4 and a region having a triangular recess as shown in FIG. . Then, by optimizing the surface conditions, the diffractive optical element 5 having a desired function can be formed.

  Here, an example of a method for manufacturing the diffractive optical element 5 will be described with reference to FIG. As shown in FIG. 6A, 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, an etching process is performed to form a mold made of quartz as shown in FIG. 6B. 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. 6C, 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. Thereby, as shown in FIG. 6D, 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. 7 is a schematic diagram showing the first surface 11 illuminated by the illumination device 1 including the diffractive optical element 5. As shown in FIG. 7, the illumination device 1 including the diffractive optical element 5 can set an illumination area LA on the first surface 11. Specifically, the illumination device 1 including the diffractive optical element 5 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 5 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 (rectangular), and the illuminating device 1 including the diffractive optical element 5 has an illumination area LA corresponding to the first surface 11. Set. The size and shape of the illumination area LA can be set by appropriately adjusting the surface conditions of the diffractive optical element 5 (pitch d between the recesses 5M, depth t of the recesses 5M, etc.). In other words, the diffractive optical element 5 can have a function as an illumination region setting optical system by optimizing the surface conditions including the pitch d between the recesses 5M and the depth t of the recesses 5M. Further, by optimizing the surface conditions of the diffractive optical element 5, it is possible to generate diffracted light L3 that can make the illuminance in the illumination area LA uniform, and light is emitted from the light exit surface of the diffractive optical element 5. The first surface 11 can be illuminated with an illumination area LA that is larger than the exit area. Then, by optimizing the surface condition of the diffractive optical element 5 using a predetermined method such as the above-described iterative Fourier method, it has desired functions (an illumination area setting function, a diffused light generation function, an enlarged illumination function, etc.). The diffractive optical element 5 can be formed.

  That is, the diffractive optical element 5 of the present embodiment has an illumination area setting function, an illuminance uniformity function (diffuse light generation function), and an enlarged illumination function, and the recess 5M so as to have these functions. The surface conditions including the pitch d and the depth t of the recess 5M are optimized.

  In the present embodiment, the diffractive optical element 5 has the illumination area LA set in a rectangular shape, but by optimizing the surface conditions including the pitch d between the recesses 5M and the depth t of the recesses 5M, For example, the illumination area LA can be set to an arbitrary shape such as a line shape or a circular shape.

  The diffractive optical element 5 is optimized so as to illuminate the first surface 11 with the generated primary light.

  Returning to FIG. 1, an angle adjusting optical element 6 is provided between the diffractive optical element 5 and the first surface 11. The angle adjusting optical element 6 is irradiated with the diffracted light (primary light) L3 from the diffractive optical element 5, and has an angle adjusting function for adjusting the emission angle of the emitted light. The angle adjusting optical element 6 is composed of a refractive lens (field lens). The refractive lens includes an axial target lens that is rotationally symmetric with respect to the optical axis, such as a spherical lens or an aspherical lens. Alternatively, the angle adjusting optical element 6 may include a Fresnel lens or the like. The angle adjusting optical element 6 can adjust the emission angle of the light emitted from the diffractive optical element 5, and hence the incident angle of the light with respect to the first surface 11. In the present embodiment, the angle adjusting optical element 6 is diffracted light (primary light) L3 generated by the diffractive optical element 5 based on the plurality of laser lights L1 emitted from the plurality of laser light source devices 2, respectively. Optimized so that the emission angle of the emitted light can be adjusted so as to illuminate a predetermined region on the first surface 11 in a superimposed manner.

  FIG. 8 is a schematic configuration diagram showing 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. 8, the projection type image display apparatus 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 projection type image display device PJ of the present embodiment uses the screen 100 as a transmission 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 plurality of laser light source devices 2 of the first illumination device 1R each emit red (R) laser light. The first illumination device 1R generates diffused light L2 by the diffusing optical element 4 based on the red laser light L1, and generates diffracted light L3 by the diffractive optical element 5 based on the generated diffused light L2. The incident surface 11 of the first light valve 10R is illuminated with the diffracted light L3.

  The plurality of laser light source devices 2 of the second illumination device 1G each emit green (G) laser light. The second illuminating device 1G generates the diffused light L2 by the diffusing optical element 4 based on the green laser light L1, and generates the diffracted light L3 by the diffractive optical element 5 based on the generated diffused light L2. The incident surface 11 of the second light valve 10G is illuminated with the diffracted light L3.

  The plurality of laser light source devices 2 of the third illumination device 1B each emit blue (B) laser light. The third illuminating device 1G generates the diffused light L2 by the diffusing optical element 4 based on the blue laser light L1, and generates the diffracted light L3 by the diffractive optical element 5 based on the generated diffused light L2. The incident surface 11 of the third light valve 10B is illuminated with the diffracted light L3.

  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 present embodiment, the diffractive optical element 5 generates the diffracted light L3 from the diffused light L2 from the diffused optical element 4, and illuminates the first surface 11 with the diffracted light L3. Even if zero-order light is generated from the diffractive optical element 5, it is possible to suppress an increase in local illuminance (luminance) on the first surface 11 of the zero-order light. In the present embodiment, the diffractive optical element 5 is designed not to generate zero-order light using a predetermined method such as the above-described iterative Fourier method, and the generated primary light has a uniform illuminance distribution. The first surface 11 is designed so as to be able to illuminate. For example, it is caused by a manufacturing error (process error) when manufacturing the diffractive optical element 5, a wavelength error of the laser light L1 emitted from the laser light source device 2, and the like. Thus, there is a possibility that zero-order light is generated from the diffractive optical element 5. An error (blurring) in the wavelength of the laser light L1 emitted from the laser light source device 2 is caused by, for example, a temperature change. The 0th order light is often formed on an extension line of light incident on the diffractive optical element 5, and the light intensity of the 0th order light is a value corresponding to the intensity (illuminance) of the light incident on the diffractive optical element 5. In many cases. In such a case, when the laser light L1 from the laser light source device 2 is directly incident on the diffractive optical element 5, the extension of the laser light L1 incident on the diffractive optical element 5 in the first surface 11 is extended. In some cases, the area on the line is irradiated with zero-order light, and the illuminance (luminance) of the portion irradiated with the zero-order light locally increases. In that case, an image formed based on the spatial light modulation device 10 is defective. In the present embodiment, the diffused light L2 generated by the diffuser optical element 4 is incident on the diffractive optical element 5, and the light incident on the diffractive optical element 5 is diffused (dispersed). . Therefore, an increase in local illuminance (luminance) of light incident on the diffractive optical element 5 is suppressed. Therefore, even if 0th-order light is generated from the diffractive optical element 5, the light intensity of the 0th-order light is reduced. Therefore, as shown in the schematic diagram of FIG. An increase in local illuminance (luminance) on the first surface 11 is suppressed, and the lighting device 1 can illuminate the first surface 11 in a substantially desired state. Therefore, the image display device PJ having the illumination device 1 can form a desired image by light through the first surface (incident surface) 11.

  Moreover, according to the illuminating device 1 of this embodiment, the 1st surface 11 can be efficiently illuminated with uniform illuminance distribution, suppressing the enlargement and complexity of an apparatus, or the raise of apparatus cost. That is, when an optical system such as a rod integrator or fly-eye lens is used to illuminate the first surface 11 with a uniform illuminance distribution using the laser light emitted from the laser light source device, the number of parts is increased. There is a possibility that the optical system becomes complicated and the entire apparatus becomes large 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 5 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 5, it is possible to irradiate almost all of the light generated by the diffractive optical element 5 onto the first surface 11 and improve the light utilization efficiency. 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.

  Moreover, in this embodiment, since the illuminating device 1 is provided with the several laser light source device 2, the light quantity (illuminance) on the 1st surface 11 can be increased. And by displaying an image with the light via the 1st surface 11 illuminated with the illuminating device 1, the high brightness | luminance and high contrast of an image are realizable.

  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 diffracted 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).

  Moreover, by providing the angle adjusting optical element 6, the incident angle of light with respect to the first surface 11 can be reduced, and the first surface 11 can be efficiently illuminated. In addition, a predetermined region on the first surface 11 can be superimposedly illuminated with the diffracted light L3 generated by the diffractive optical element 5 based on the laser light L1 emitted from each of the plurality of laser light source devices 2. 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.

  Further, as described with reference to FIG. 6 and the like, since the diffractive optical element 5 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. A characteristic part of this embodiment is that a lens is used as the diffusing optical element 4. 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.

  FIG. 10A is a diagram illustrating the lighting device 1 according to the second embodiment. In FIG. 10A, the lighting device 1 includes a plurality of laser light source devices 2. The plurality of laser light source devices 2 are arranged in an array. The illumination device 1 has a lens surface 4L that receives the laser light L1 emitted from each of the plurality of laser light source devices 2 and diffuses the incident laser light L1 to generate diffused light L2. The diffractive optical element 4 and the diffractive optical element 5 that generates the diffracted light L3 from the diffused light L2 from the diffused optical element 4 and illuminates the first surface 11 with the diffracted light L3 are provided. Between the diffractive optical element 5 and the first surface 11, there is provided an angle adjusting optical element 6 that irradiates light from the diffractive optical element 5 and adjusts an emission angle of the emitted light. The optical element 5 irradiates the first surface 11 with the generated diffracted light L3 via the angle adjusting optical element 6. The lens surface 4L is provided on one surface of the diffusing optical element 4 close to the laser light source device 2. A plurality of lens surfaces 4 </ b> L of the diffusing optical element 4 are provided so as to correspond to the plurality of laser light source devices 2. The diffusing optical element 4 having the lens surface 4L can transmit light, and the lens surface 4L diffuses the incident laser light L1 to generate diffused light L2. The generated diffused light L2 passes through the optical element 4, and then exits from the other surface close to the diffractive optical element 5, and is converted into diffracted light L3 by the diffractive optical element 5. Thus, the diffusing optical element 4 can be configured by a lens system. Even if zero-order light is generated in the diffractive optical element 5 by causing the diffused light L2 generated by the diffusing optical element 4 to enter the diffractive optical element 5, as shown in the schematic diagram of FIG. An increase in local illuminance (luminance) of zero-order light on the first surface 11 can be suppressed.

<Third Embodiment>
A third embodiment will be described. A characteristic part of this embodiment is that the generated diffused light L2 is collimated.

  FIG. 11A is a diagram illustrating the lighting device 1 according to the third embodiment. In FIG. 11A, an illuminating device 1 includes a plurality of laser light source devices 2 arranged in an array, a diffusing optical element 4 that diffuses laser light L1 to generate diffused light L2, and a diffusing optical element 4. A diffractive optical element 5 that generates diffracted light L3 from the diffused light L2 and illuminates the first surface 11 with the diffracted light L3. Between the diffractive optical element 5 and the first surface 11, there is provided an angle adjusting optical element 6 that irradiates light from the diffractive optical element 5 and adjusts an emission angle of the emitted light. The optical element 5 irradiates the first surface 11 with the generated diffracted light L3 via the angle adjusting optical element 6.

  The diffusing optical element 4 receives the laser light L1 emitted from each of the plurality of laser light source devices 2, and diffuses the incident laser light L1 to generate diffused light L2, and a lens. And a second lens surface (collimating surface) 4H that collimates the diffused light L2 generated on the surface 4L. The lens surface 4L is provided on one surface of the diffusing optical element 4 close to the laser light source device 2. On the other hand, the collimating surface 4H is provided on the other surface of the diffusing optical element 4 close to the diffractive optical element 5. A plurality of lens surfaces 4L of the diffusing optical element 4 are provided so as to correspond to the plurality of laser light source devices 2, and a plurality of collimating surfaces 4H are provided so as to correspond to the lens surfaces 4L. The lens surface 4L diffuses the incident laser light L1 to generate diffused light L2. The diffusing optical element 4 can transmit light, and the diffusing light L2 generated on the lens surface 4L is transmitted through the diffusing optical element 4 and then collimated by the collimating surface 4H. The diffused light L2 emitted from the other surface including the collimating surface 4H is converted into diffracted light L3 by the diffractive optical element 5.

  As described above, in the present embodiment, the diffused light L2 generated on the lens surface 4L is collimated on the collimating surface 4H, so that the incident surface of the diffractive optical element 5 can be vertically illuminated by the diffused light L2, for example. For example, the incident angle of light with respect to the diffractive optical element 5 can be reduced. Therefore, the design of the diffractive optical element 5 can be easily performed, and a decrease in diffraction efficiency can be suppressed. Then, even if zero-order light is generated in the diffractive optical element 5 by making the light incident on the diffractive optical element 5 into the diffused light L2 by the diffusing optical element 4, it is shown in the schematic diagram of FIG. As described above, an increase in local illuminance (luminance) of the zero-order light on the first surface 11 can be suppressed.

<Fourth embodiment>
A fourth embodiment will be described. A characteristic part of this embodiment is that a diffractive optical element 4K is used as the diffusing optical element 4.

  FIG. 12A is a diagram illustrating the lighting device 1 according to the fourth embodiment. In FIG. 12A, an illuminating device 1 includes a plurality of laser light source devices 2 arranged in an array, and a diffusion diffractive optical element (diffusion optical element) 4K that diffuses laser light L1 to generate diffused light L2. And a diffractive optical element 5 that generates diffracted light L3 from the diffused light L2 from the diffractive optical element for diffusion 4K and illuminates the first surface 11 with the diffracted light L3. Between the diffractive optical element 5 and the first surface 11, there is provided an angle adjusting optical element 6 that irradiates light from the diffractive optical element 5 and adjusts an emission angle of the emitted light. The optical element 5 irradiates the first surface 11 with the generated diffracted light L3 via the angle adjusting optical element 6.

  The diffractive diffractive optical element 4K receives the laser light L1 emitted from each of the plurality of laser light source devices 2, and diffuses the incident laser light L1 to generate diffused light L2. That is, the diffusion diffractive optical element 4K has a diffused light generation function. By optimizing the surface conditions of the diffractive optical element 4K using a predetermined method such as the above-described iterative Fourier method, the diffractive optical element 4K having a diffused light generation function can be formed. In the present embodiment, the diffractive optical element 4K for diffusion has a maximum value of the light intensity (illuminance) of the zero-order light of the diffused light L2 to be emitted is less than 5% with respect to the light intensity (illuminance) of the incident laser light L1. The diffused light L2 is generated so that

  On the other hand, the diffractive optical element 5 has an illumination area setting function as in the above-described embodiment, and the illumination area LA on the first surface 11 can be set to a rectangular shape by the generated diffracted light L3. .

Thus, the diffractive optical element 4K can be used as the diffusing optical element 4. Then, even if zero-order light is generated in the diffractive optical element 5 by making the light incident on the diffractive optical element 5 into the diffused light L2 by the diffusing optical element 4, it is shown in the schematic diagram of FIG. As described above, an increase in local illuminance (luminance) of the zero-order light on the first surface 11 can be suppressed. In the present embodiment, even when zero-order light is generated from the diffractive optical element 5,

The diffractive optical element 5 so that the maximum value of the 0th-order light intensity (illuminance) of the emitted diffracted light L3 is less than 5% with respect to the 0th-order light intensity (illuminance) of the incident laser light L2. Is created, the light intensity (illuminance) of the zero-order light of the diffracted light L3 can be less than 0.25% with respect to the light intensity (illuminance) of the laser light L1.

  Also, as described with reference to FIG. 6 and the like, the diffractive diffractive optical element 4K can be manufactured by the nanoimprint technique, so that a large number of diffractive optical elements can be easily manufactured, and the manufacturing cost is reduced. can do.

<Fifth Embodiment>
A fifth embodiment will be described. The characteristic part of this embodiment is that the diffusion optical element 4 is provided on one surface of the substrate 7 that can transmit light, and the diffractive optical element 5 is provided on the other surface.

  FIG. 13 (A) is a diagram showing the lighting apparatus 1 according to the fifth embodiment. In FIG. 13A, an illuminating device 1 includes a plurality of laser light source devices 2 arranged in an array, a diffusing optical element 4 that diffuses laser light L1 to generate diffused light L2, and a diffusing optical element 4. A diffractive optical element 5 that generates diffracted light L3 from the diffused light L2 and illuminates the first surface 11 with the diffracted light L3. Between the diffractive optical element 5 and the first surface 11, there is provided an angle adjusting optical element 6 that irradiates light from the diffractive optical element 5 and adjusts an emission angle of the emitted light. The optical element 5 irradiates the first surface 11 with the generated diffracted light L3 via the angle adjusting optical element 6.

  In the present embodiment, the illumination device 1 includes a substrate 7 that can transmit light, and the diffusing optical element 4 is provided on one surface of the substrate 7 close to the laser light source device 2, and is a diffractive optical element. 5 is provided on the other surface close to the first surface 11 (angle adjusting optical element 6). The substrate 7 is made of, for example, a transparent synthetic resin film member or a glass plate member such as quartz. In the present embodiment, the diffusing optical element 4 is configured by a lens surface 4 </ b> L provided on one surface of the substrate 7. A plurality of lens surfaces 4L are provided so as to correspond to the plurality of laser light source devices 2, and diffuse the incident laser light L1 to generate diffused light L2. The substrate 7 can transmit light, and the diffused light L2 generated on the lens surface 4L is transmitted through the substrate 7 and then converted into diffracted light L3 by the diffractive optical element 5. In the present embodiment, the diffractive optical element 5 includes a recess (5M) provided on the other surface of the substrate 7.

  In this way, it is possible to provide the diffusing optical element 4 on one surface of the substrate 7 that can transmit light, and the diffractive optical element 5 on the other surface. Thus, the first surface 11 can be efficiently illuminated. Then, even if zero-order light is generated in the diffractive optical element 5 by making the light incident on the diffractive optical element 5 into the diffused light L2 by the diffusing optical element 4, it is shown in the schematic diagram of FIG. As described above, an increase in local illuminance (luminance) of the zero-order light on the first surface 11 can be suppressed.

  In the first to fifth embodiments described above, 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. Each of the above-described embodiments is applied to a so-called rear projector that includes a projection unit U on the back side of the screen 100 and projects light including image information onto the screen 100 from the back side of the screen 100. The lighting device 1 of the form can also be applied.

  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 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. 14, 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.

  In the first to sixth embodiments described above, the illumination device 1 has a plurality of laser light source devices 2 arranged in a one-dimensional direction (X-axis direction), but is arrayed in a two-dimensional direction (XY direction). You may provide the laser light source device 2 arrange | positioned in the shape.

  In each of the above-described embodiments, the illumination device 1 has a plurality of laser light source devices 2. However, the number of the laser light source devices 2 may be one.

  In each of the above-described embodiments, the illumination device 1 includes the angle adjusting optical element 6, but the angle adjusting optical element 6 may be omitted. In that case, the diffractive optical element 5 directly illuminates the first surface 11 with the generated diffracted light L3.

  In each of the above-described embodiments, the phase modulation type diffractive optical element is used as the diffractive optical element among the transmission type diffractive optical elements (diffraction gratings), 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.

It is a schematic block diagram which shows the illuminating device which concerns on 1st Embodiment. It is a schematic diagram which shows an example of a diffusion optical element. It is a schematic diagram which shows an example of a diffusion 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 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 which concerns on 1st Embodiment. 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 for demonstrating the effect of the illuminating device which concerns on 1st Embodiment. It is a figure for demonstrating the illuminating device which concerns on 2nd Embodiment. It is a figure for demonstrating the illuminating device which concerns on 3rd Embodiment. It is a figure for demonstrating the illuminating device which concerns on 4th Embodiment. It is a figure for demonstrating 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, 4 ... Diffusing optical element, 4A ... Base material, 4B ... Fine particle, 4D ... Optical member, 4K ... Diffraction optical element for diffusion, 5 ... Diffractive optical element, 6 ... For angle adjustment Optical element, 7 ... substrate, 10 ... spatial light modulator, 11 ... first surface (incident surface), 100 ... screen (second surface), L1 ... laser light, L2 ... diffused light, L3 ... diffracted light, LA ... Illumination area, PJ ... Image display device (projector)

Claims (7)

A laser light source device for emitting laser light;
A laser beam emitted from the laser light source device is incident, and a diffusion optical element that diffuses the incident laser beam to generate diffused light; and
A diffractive optical element that generates diffracted light from the diffused light from the diffused optical element and illuminates the first surface with the diffracted light;
The diffusion optical element has a first lens surface that diffuses the laser light emitted from the laser light source device and generates diffused light on one surface close to the laser light source device, and is close to the diffractive optical element. On the other surface, there is a second lens surface that collimates the diffused light generated on the first lens surface,
The diffractive optical element is an illumination device that converts diffused light emitted from the other surface including the second lens surface into the diffracted light.   The illumination device according to claim 1, wherein the diffractive optical element illuminates the first surface with a rectangular illumination region. Wherein provided between the diffractive optical element and the first surface, along with light is emitted from the diffractive optical element, according to claim 1 comprising an angular adjustment for an optical element for adjusting the injection angle of the exit light or 2. The lighting device according to 2 . A plurality of the laser light source devices;
Wherein the plurality of laser light source device illuminating device according to any one of claims 1 to 3 that are arranged in an array. An image display device that is illuminated by the illumination device according to any one of claims 1 to 4 and displays an image by light through the first surface. The image display device according to claim 5, wherein the first surface includes an incident surface of a spatial light modulator that modulates the illuminated light in accordance with an image signal. 7. A projector comprising the image display device according to claim 5 or 6 , comprising a projection system that projects light including image information via the first surface onto the second surface.

Images