Holding member and image projection device

Abstract

To accurately hold an optical component without interfering with vignetting of an optical beam or other components in a complicated optical system arrangement.SOLUTION: The holding member includes: a holder for holding a plate-like optical component and specifically holding one end part opposite to an irradiation surface of the optical component irradiated with light from a light source; and a leaf spring having at least two surfaces, the leaf spring pressing one end part of the optical component held by the holder by one surface and regulating the movement of the optical component in a direction parallel to the irradiation surface by another surface.SELECTED DRAWING: Figure 3-1

Description

[Technical Field]

[0001] The present invention relates to a holding member and an image projection device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known an image projection device called a projector that projects and displays an image to be projected, which is generated in an image forming unit based on image data from a personal computer, a video camera, or the like, onto a projection surface such as a screen.

[0003] In recent years, many of the optical components that make up the illumination optical system after the light source in image projection devices have been arranged in a complex manner within a housing to make the device compact by folding the optical path. This has made it necessary to hold the optical components with high precision inside the image projection device.

[0004] For example, Patent Document 1 discloses a technique in which a mirror, which is one of optical components, is pressed against an L-shaped holder by a leaf spring in order to hold the mirror with high precision. Summary of the Invention [Problem to be solved by the invention]

[0005] According to the technology disclosed in Patent Document 1, many holding members for holding optical components are present around the area where light from the optical components is incident, which poses a problem that the holding members may interfere with other optical components or may block light rays.

[0006] The present invention has been made in view of the above, and has as its object to hold optical components with high precision without causing vignetting of light or interference with other components even in a complex optical system arrangement. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the present invention provides a plate-shaped optical component, the plate-shaped optical component comprising: a holder for holding one end of a surface of the optical component opposite to an irradiation surface onto which light from a light source is irradiated; and a leaf spring having at least two surfaces, one of which presses against one end of the optical component held by the holder, and the other of which restricts movement of the optical component in a direction parallel to the irradiation surface. The holder is provided with a first fixing member for fixing the leaf spring on a surface that contacts the other surface of the leaf spring, and a positioning member for positioning the holder with respect to a base member on a surface that does not contact the leaf spring and is different from the surface on which the first fixing member is provided, and a plurality of the positioning members are provided and arranged side by side along the longitudinal direction of the optical component held in the holder. It is characterized by: [Effects of the Invention]

[0008] According to the present invention, it is possible to hold a plate-shaped optical component with high precision without causing vignetting of light or interference with other components even in a complex optical system arrangement. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a projector according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a holding structure for the first reflecting mirror. [Figure 3-1] FIG. 3-1 is a perspective view schematically illustrating a mirror holding portion that holds the first reflecting mirror. [Figure 3-2] FIG. 3-2 is a front view schematically showing the mirror holding portion. [Figure 3-3] FIG. 3-3 is an exploded perspective view of the mirror holding portion. [Figure 4-1] FIG. 4-1 is a diagram showing a schematic configuration of a leaf spring. [Figure 4-2] FIG. 4-2 is a diagram illustrating a schematic configuration of a leaf spring. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description of an embodiment of a holding member and an image projection device will be given below with reference to the accompanying drawings. In this embodiment, a projector that projects an image onto a screen or the like will be described as an example of application of the image projection device.

[0011] (Projector configuration) Fig. 1 is a diagram showing the configuration of a projector 100 according to an embodiment. Projector 100 shown in Fig. 1 includes an illumination device 110, a light tunnel 121, a lens group 122, a mirror group 123 (a first reflecting mirror 123a and a second reflecting mirror 123b), an image forming element 124, and a projection optical unit 125.

[0012] Illumination device 110 has light source 111, condenser lens 112, wavelength-selective polarization separation element (half mirror) 113, quarter-wave plate 114, lens group 115, color wheel 116, lens group 117, and phosphor wheel 118. Illumination device 110 sequentially emits blue light, red light, and green light in the same direction (on the same emission optical path) toward light tunnel 121 in a time-division manner.

[0013] In the lighting device 110, the light source 111 emits a first light having a first linear polarization component. As an example, the light source 111 may be a laser diode that emits blue laser light having a P polarization component (P wave) and a wavelength λB.

[0014] Note that a light emitting diode (Light Emitting Diode) or an organic EL (Electro Luminescence) element that emits blue light may be used as light source 111, or a light source that combines these may be used. Alternatively, a laser diode, a light emitting diode, an organic EL element, or the like that emits light in the ultraviolet wavelength region may be used, or a light source that combines these may be used.

[0015] Blue laser light emitted from light source 111 is incident as a substantially parallel beam via condenser lens 112 on wavelength-selective polarization separation element 113. The tilt angle and left / right rotation position of wavelength-selective polarization separation element 113 are adjusted by an angle adjustment mechanism. Of the P and S waves of wavelength λB from light source 111, wavelength-selective polarization separation element 113 transmits the P waves and reflects the S waves.

[0016] The P-wave blue laser light incident on wavelength-selective polarization separation element 13 passes through wavelength-selective polarization separation element 113, converts linearly polarized light into circularly polarized light, and is guided to quarter-wave plate 114, which converts circularly polarized light into linearly polarized light. Quarter-wave plate 114 converts the P-wave blue laser light into circularly polarized blue laser light, and irradiates it onto color wheel 116 via lens group 115.

[0017] The color wheel 116 has a configuration in which a disk-shaped member is divided into multiple sector-shaped regions (segments). Specifically, the color wheel 116 is divided into a total of three sector-shaped regions (segments): a red (R) region, a green (G) region, and a transparent transmission region.

[0018] A driving unit 116m such as a stepping motor that rotates the color wheel 116 is provided at the axis of the color wheel 116. When the color wheel 116 is rotated at a predetermined timing by the driving of the driving unit 116m, the incident position of the light from the lens group 115 switches to one of the areas (segments) of the red (R) area, the green (G) area, and the transmission area.

[0019] That is, the wavelength of the light collected by the lens group 115 and the area (segment) selectively arranged at the incident position of the light from the lens group 115 determine whether the light incident on the color wheel 116 is transmitted through the color wheel 116 or reflected by the color wheel 116.

[0020] When the transmission region is positioned at the incident position of light from lens group 115, the blue laser light incident on color wheel 116 passes through color wheel 116 to become blue illumination light, which then enters light tunnel 121. Because the blue illumination light passing through color wheel 116 is circularly polarized light, it is possible to reduce speckles that appear on a screen or the like.

[0021] On the other hand, when the red (R) region or green (G) region is positioned at the incident position of light from lens group 115, the blue laser light incident on color wheel 116 is reflected by color wheel 116. Then, the blue laser light reflected by color wheel 116 passes through lens group 115 and is incident on quarter-wave plate 114. The light incident on quarter-wave plate 114 is converted from circularly polarized light to S-wave light, and is incident on wavelength-selective polarization separation element 113. The S-polarized component is a component orthogonal to the P-polarized component.

[0022] The S-wave blue laser light incident on wavelength-selective polarization separation element 113 is reflected by wavelength-selective polarization separation element 113, passes through lens group 117, and is incident on phosphor wheel 118. That is, wavelength-selective polarization separation element 113 guides the S-wave (S-polarized) light to phosphor wheel 118.

[0023] The lens group 117 is configured by appropriately combining, for example, biconvex lenses, plano-convex lenses, etc., and has the function of converging an approximately parallel light beam into a spot on the phosphor wheel 18, and the function of converging divergent light from the phosphor wheel 18 and converting it into an approximately parallel light beam.

[0024] Phosphor wheel 118 is formed by arranging a yellow phosphor on a disk-shaped member along the rotation direction of the plate. The yellow phosphor uses the blue laser light as excitation light to generate yellow fluorescence with a longer wavelength than the blue laser light. A drive unit 118m, such as a stepping motor, that rotates phosphor wheel 118 is provided at the axis of phosphor wheel 118.

[0025] Yellow phosphor 181 of phosphor wheel 118 uses the incident blue laser light as excitation light to generate yellow fluorescence with a longer wavelength than the blue laser light. The yellow fluorescence is incident on wavelength-selective polarization separation element 113 via lens group 117. Since the yellow fluorescence has a wavelength of, for example, 500 nm or more, it is reflected by wavelength-selective polarization separation element 113 and incident on color wheel 116 via quarter-wave plate 114 and lens group 15.

[0026] The yellow fluorescence incident on color wheel 116 is converted into red illumination light or green illumination light by the red (R) region or green (G) region, and enters light tunnel 121. The illuminance distribution of each illumination light is made uniform by light tunnel 121, and the light passes through lens group 122 and is reflected by mirror group 123 (first reflecting mirror 123a and second reflecting mirror 123b) to irradiate image forming element 124.

[0027] The image forming element 124 forms a color projection image by controlling the gradation of each illumination light for each pixel. For example, a DMD (Digital Micromirror Device) can be used as the image forming element 124. The DMD has a micromirror for each pixel, and each micromirror can maintain one of two different angle states.

[0028] That is, each micromirror of the DMD is in one of two states: an angle that reflects each illumination light toward the projection optical unit 125 (ON state), and an angle that reflects each illumination light toward an internal absorber and does not emit it to the outside (OFF state). This makes it possible to control the light projected for each pixel to be displayed. Furthermore, the DMD can express gradation for each pixel to be displayed by adjusting the time ratio of each micromirror in the ON state using a pulse width modulation method (PWM method).

[0029] The image forming element 124 is not limited to a DMD, and may be, for example, a liquid crystal or the like, as long as it is an element that can form a color projection image using the illumination light from the illumination device 10.

[0030] The red, green, and blue illumination lights are irradiated onto the image forming element 124 in a time-division manner at the timing of generating an image, and after the image forming element 124 performs gradation control for each display pixel, the light is projected onto a screen or the like via the projection optical unit 125. Then, due to the afterimage phenomenon in the eyes, a color image is visually recognized through the screen or the like.

[0031] Next, the structure for holding the first reflecting mirror 123a will be described.

[0032] Here, Fig. 2 is a diagram showing an example of a holding structure for first reflecting mirror 123a. As shown in Fig. 2, first reflecting mirror 123a is a rectangular plate-shaped optical component. As shown in Fig. 2, first reflecting mirror 123a, which is irradiated with light from light source 111, is held by mirror holding section 150 which functions as a holding member.

[0033] Next, the mirror holding unit 150 will be described.

[0034] 3-1 is a perspective view that schematically shows the mirror holding unit 150 that holds the first reflecting mirror 123a, FIG. 3-2 is a front view that schematically shows the mirror holding unit 150, and FIG. 3-3 is an exploded perspective view of the mirror holding unit 150. As shown in FIGS. 3-1 to 3-3, the mirror holding unit 150 includes a holder 151 and a leaf spring 152. The holder 151 holds the first reflecting mirror 123a, which has a rectangular plate shape and is irradiated with light from the light source 111. The leaf spring 152 presses the first reflecting mirror 123a against the holder 151 to fix it in place.

[0035] Holder 151 has a recess 151a. Holder 151 holds, in recess 151a, one end of the surface opposite to the irradiation surface that is irradiated with light from light source 111, out of both surfaces of rectangular plate-shaped first reflecting mirror 123a. Holder 151 also includes boss 151b for leaf spring 152, which is a first fixing member that fixes leaf spring 152, at an arbitrary position on the surface that contacts leaf spring 152 and is perpendicular to recess 151a.

[0036] Furthermore, holder 151 is provided with positioning member 151c for positioning with respect to base member 160 (see FIG. 2) at an arbitrary location on a surface that does not come into contact with leaf spring 152 and is different from the surface on which leaf spring boss 151b is arranged. Positioning member 151c is made up of two or more pin-shaped pin members. The pin members are arranged side by side along the longitudinal direction of first reflecting mirror 123a held by holder 151. As a result, since positioning member 151c is provided at an arbitrary location away from plate-shaped first reflecting mirror 123a, first reflecting mirror 123a can be positioned with high precision with respect to base member 160 even inside a crowded optical system.

[0037] Next, the leaf spring 152 will be described. Here, FIGS. 4-1 and 4-2 are diagrams showing a schematic configuration of the leaf spring 152. As shown in FIGS. 4-1 and 4-2, the leaf spring 152 has an L-shape formed by two surfaces: a mirror biasing surface 152a that biases the first reflecting mirror 123a, and a mirror fall-off prevention surface 152b that prevents the first reflecting mirror 123a from falling off. The angle formed by the mirror biasing surface 152a and the mirror fall-off prevention surface 152b is approximately 90 degrees. The mirror biasing surface 152a of the leaf spring 152 has a screw hole 152c that is used for fastening to the holder 151 with a screw 153.

[0038] Furthermore, the mirror fall-off prevention surface 152b of the leaf spring 152 has a fitting hole 152d which is a second fixing member that fits into and engages with a boss 151b for the leaf spring provided on the holder 151. By fitting the fitting hole 152d into the boss 151b for the leaf spring provided on the holder 151, the leaf spring 152 is prevented from coming off.

[0039] The leaf spring 152 is positioned above one end of the first reflecting mirror 123a fitted in the recess 151a of the holder 151, and has a fitting hole 152d fitted into a boss 151b for the leaf spring provided on the holder 151, and is fastened to the holder 151 with a screw 153. In this way, the leaf spring 152 biases the first reflecting mirror 123a fitted in the recess 151a of the holder 151 from above.

[0040] 3-1 to 3-3, the mirror holding unit 150 holds only one side of the first reflecting mirror 123a by pressing one side of the first reflecting mirror 123a with the recess 151a of the holder 151 and the mirror biasing surface 152a of the leaf spring 152. Therefore, when a dichroic mirror that reflects light of a specific wavelength and transmits light of other wavelengths is used as the first reflecting mirror 123a, the light beam that transmits through the dichroic mirror can be used.

[0041] As shown in Figures 3-1 to 3-3, the mirror holding part 150 uses the mirror fall-out prevention surface 152b of the leaf spring 152 to restrict movement of the first reflecting mirror 123a in a direction parallel to the irradiation surface of the first reflecting mirror 123a, thereby preventing the first reflecting mirror 123a from falling out.

[0042] As described above, according to this embodiment, the top, bottom, and back sides of first reflecting mirror 123a are not covered by holding members, so positioning can be performed with ample space, and therefore light vignetting and interference with other components can be avoided even in a complex optical system arrangement, and only one end of plate-shaped first reflecting mirror 123a can be held with high precision by recess 151a of holder 151 and plate spring 152. Furthermore, light passing through plate-shaped first reflecting mirror 123a can also be used.

[0043] It should be noted that the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[0044] The present invention is also applicable to various devices that have optical components such as mirrors, such as camera devices, printer devices, 3D printer devices (three-dimensional modeling devices), and 3D scanner devices.

[0045] In other words, while the above-described embodiment is an example in which the present invention is applied to a projector that projects an image onto a screen or the like, the present invention can be applied to various devices other than projectors that have optical components arranged in the optical path. As one example, the present invention can be applied to a stereolithography 3D printer device that has a laser as a light source unit inside. Furthermore, some stereolithography 3D printer devices have an ultraviolet light source as a light source unit and a DMD as an image forming unit. The present invention can also be applied to optical components arranged in the optical path within these devices.

[0046] Furthermore, the 3D scanner device includes, for example, a laser light source that emits light and a light receiving unit that receives reflected light from the object to be scanned. The present invention can also be applied to optical components on the optical path within these devices. [Explanation of symbols]

[0047] 100 Image projection device 111 Light source 123a Plate-shaped optical components 124 Image forming element 150 Retaining member 151 Holder 151a recess 151b First fixing member 151c Positioning member 152 Leaf spring 152d Second fixing member 160 Base material [Prior art documents] [Patent documents]

[0048] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-311369

Claims

1. a holder for holding a plate-shaped optical component, the holder holding one end of a surface of the optical component opposite to an irradiation surface onto which light from a light source is irradiated; a leaf spring having at least two surfaces, one surface of which presses one end of the optical component held by the holder, and the other surface of which restricts movement of the optical component in a direction parallel to the irradiation surface; Equipped with the holder includes a first fixing member for fixing the leaf spring on a surface of the holder that contacts the other surface of the leaf spring, and a positioning member for positioning the holder relative to a base member on a surface of the holder that does not contact the leaf spring and is different from the surface on which the first fixing member is provided, a plurality of the positioning members are provided and arranged side by side along the longitudinal direction of the optical component held by the holder; A holding member characterized by:

2. The leaf spring has a second fixing member on the other surface that engages with the first fixing member provided on the holder. The holding member according to claim 1 .

3. the holder has a recess for holding one end of the optical component; 3. The holding member according to claim 1 or 2.

4. The positioning member is a pin member having two or more pin shapes. The holding member according to claim 1 .

5. A plate-shaped optical component; a holding member according to claim 1 that holds the optical component; a light source that irradiates light onto the optical component held by the holding member; an image forming element that forms a projected image by controlling the gradation of the light reflected by the optical component for each pixel; An image projection device comprising:

Images