JP2007279136A - Optical element, optical element module having the same, optical device equipped with the module, and method for manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element that can be easily mounted with high mounting accuracy. <P>SOLUTION: A prism 20 comprises a prism body 22 and a flange 21, wherein the prism body 22 is formed in a polygonal column having two light transmitting faces 22a, 22b and a reflecting face 22c on the side faces. The flange 21 is formed at an end near the light transmitting face 22a as protruding outward from both ends 22d, 22e of the prism body 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical element, an optical element module including the optical element, an optical device including the optical element, and a method for manufacturing the optical element.

  In recent years, the quality required for precision optical devices such as digital still cameras has been increasing year by year. Along with this, demands for the accuracy of attaching optical elements to precision optical devices and the positioning accuracy of optical elements are increasing year by year. In particular, in a so-called bending optical system using a prism, high mounting accuracy of optical elements and high positioning accuracy between optical elements are required.

In view of this situation, various optical element attachment methods and optical elements (for example, prisms) that can be attached with high attachment accuracy have been proposed (for example, Patent Document 1).
JP-A-9-73005

  However, the conventional optical element and the method for attaching the optical element have a problem that it is difficult to attach the optical element with sufficiently high accuracy and ease. Therefore, there is a problem that it is difficult to easily realize a high-quality optical device.

  The present invention has been made in view of the above points, and an object thereof is to provide an optical element that can be easily attached with high attachment accuracy.

  The optical element according to the present invention includes an element main body and a collar part. The element main body is formed in a polygonal column shape in which two light transmission surfaces and a light reflection surface are formed on the side surface. The flange portion is formed at an end portion of one of the two light transmission surfaces close to one surface so as to protrude outward from both end surfaces of the element body.

  The optical element module according to the present invention includes a folder and an optical element. An opening is formed in the folder. The optical element includes an element body and a collar part. The element main body is formed in a polygonal column shape having two light transmission surfaces and a light reflection surface as side surfaces, and is inserted into the opening. The flange portion is formed at an end portion of one of the two light transmission surfaces close to one surface so as to protrude outward from both end surfaces of the element body. The buttocks are in contact with the folder.

  An optical device according to the present invention includes an optical element module including a folder having an opening and an optical element. The optical element is formed in a polygonal column shape having two light transmission surfaces and a light reflection surface as side surfaces, and is disposed at the end of the element main body inserted into the opening and near one surface of the two light transmission surfaces. It is formed so as to protrude outward from both end faces of the element body, and has a flange portion that comes into contact with the folder.

  The manufacturing method according to the present invention includes a polygonal columnar element body having two light transmission surfaces and a light reflection surface formed on the side surfaces, and both end surfaces of the element body at one end of the two light transmission surfaces. And an eaves part formed so as to protrude outward from the optical element. The manufacturing method according to the present invention is characterized in that an optical element is obtained by heating and pressing a base material.

  According to the present invention, a high-quality optical device can be easily realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram illustrating a configuration of a main part of the imaging apparatus 1 according to the first embodiment.

  FIG. 2 is a perspective view of the prism module 2.

  FIG. 3 is a perspective view of the prism 20.

  FIG. 4 is a cross-sectional view of a portion cut out along a cut line IV-IV in FIG.

  FIG. 5 is a cross-sectional view of a portion cut out by a cut line VV in FIG.

  As illustrated in FIG. 1, the imaging apparatus 1 according to the first embodiment includes a light receiving element 11 and lens groups 12 to 14 (first lens group 14, second lens group 13, and third lens group 12. ) And the prism module 2. The prism module 2 includes a prism 20 and a lens 16 disposed in the optical path of the imaging optical system.

  The first lens group 14 is disposed so as to be exposed from the imaging device 1 so that external light is incident thereon. External light incident from the first lens group 14 enters the prism module 2. Incident light is converted into light in different optical axis directions by the prism module 2. The converted light is imaged on the light receiving element 11 by the second lens group 13 and the third lens group 12. The formed image is converted and output to an electrical signal in the light receiving element 11 and recorded in a recording unit (for example, a memory or the like) not shown in FIG. The light receiving element 11 can be constituted by, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

  Hereinafter, the configuration of the prism module 2 will be described in detail mainly with reference to FIGS.

  The prism module 2 includes a prism 20, a prism folder 15, and a lens 16 attached to the prism folder 15. As shown in FIG. 3, the prism 20 includes a prism main body 22 and a flange 21. The prism main body 22 is formed in a polygonal prism shape (specifically, a right triangular prism shape) having two light transmission surfaces 22a and 22b and a light reflection surface 22c that are perpendicular to each other. The flange portion 21 is formed in a ring shape so as to protrude outward from both end surfaces 22d and 22e at an end portion from the light transmission surface 22a.

  The light transmission surface 22a may be a flat surface. Further, the entire or part of the light transmission surface 22a may be spherical or aspheric. For example, as shown in FIG. 5, when light enters the prism 20 from the light transmission surface 22a, the optically effective area (area through which light is transmitted) of the light transmission surface 22a may be formed in a concave shape. According to such a configuration, an imaging function can be imparted to the prism 20. Furthermore, the entire or part of the light transmission surface 22b may be a spherical surface or an aspherical surface.

  On the other hand, the prism folder 15 is provided with a pair of plate-like bodies 15 a and 15 b each having a recess corresponding to the shape of the prism main body 22. Specifically, each plate-like body 15a, 15b includes concave curved surface portions 15e, 15f provided along the peripheral surface of a (virtual) cylinder, and plane portions 15c, 15d parallel to the bottom surface of the cylinder. And have. An opening is formed by the curved surface portions 15e and 15f.

  The prism main body 22 is inserted into the openings formed by the curved surface portions 15e and 15f so as to contact the curved surface portions 15e and 15f and so that the flange portion 21 contacts the flat surface portions 15c and 15d. For this reason, the position of the prism 20 in the depth direction of the prism folder 15 is regulated by the flange 21. Therefore, it is not necessary to adjust the position of the prism 20 in the depth direction of the prism folder 15, and the prism 20 can be easily and accurately attached by only inserting the prism 20 into the prism folder 15.

  In the first embodiment, both end surfaces 22d and 22e of the prism 20 are formed in a curved shape so as to constitute a part of the circumferential surface of the cylinder. Specifically, it is formed so as to constitute a part of a circumferential surface of a cylinder whose central axis is an axis A extending in the normal direction from the center of the light transmission surface 22a. For this reason, the prism 20 can be rotated around the axis A even after being attached to the prism holder 15. Therefore, even after the prism holder 15 is attached, the inclination of the prism 20 with respect to other optical members (for example, the lens 16, the lens group 12, 13, etc.) can be adjusted precisely (for example, on the order of 1 '). Therefore, the prism 20 can be arranged with higher accuracy, and the high-quality imaging device 1 can be realized.

  Further, even when the holding position of the prism 20 is out of order due to heat, external stress, or the like while using the imaging device 1, maintenance can be easily performed.

  The prism 20 is preferably fixed to the prism folder 15 after adjusting the inclination of the prism 20. Fixing to the prism folder 15 may be performed by heat caulking, for example, or may be performed using an adhesive.

  In the first embodiment, the material of the prism 20 is not particularly limited. For example, the prism 20 may be made of plastic or glass (including crystallized glass). Of these, glass is particularly preferable. By forming the prism 20 from glass, high shape accuracy, high heat resistance, high mechanical durability, and high homogeneity can be achieved. Further, since glass has a relatively small coefficient of thermal expansion and photoelastic constant, even when the temperature of the imaging device 1 rises, the prism 20 is hardly distorted, and the optical performance of the prism 20 changes (deteriorates). ) Hard to do.

  Furthermore, in the case of glass, it is easy to make the refractive index of the prism 20 relatively high. By increasing the refractive index of the prism 20, the optical path length of the optical system (the lens groups 12 to 14, the prism module 2, and the light receiving element 11) of the imaging device 1 can be shortened. Therefore, the imaging device 1 can be made more compact.

  Further, by increasing the refractive index of the prism 20, the light reflectance of the light reflecting surface 22c can be improved. The light reflecting surface 22c is formed so that the light reflectance of visible light (light having a wavelength of 400 nm or more and 700 nm or less) incident perpendicularly to the light transmitting surface 22a is 90% or more (and 95% or more). It is preferable. From the viewpoint of realizing such a high reflectance, the refractive index of the d-line (light having a wavelength of 589 nm) of the prism 20 is preferably 1.6 or more. Furthermore, it is preferable that it is 1.65 or more. The prism 20 preferably has a high visible light transmittance.

  For example, when the refractive index of the prism 20 is low (for example, when the prism 20 is formed of low refractive index glass or plastic), a light reflecting film (not shown) may be formed on the light reflecting surface 22c. good. By doing so, the light reflectivity in the light reflection surface 22c can be improved. Therefore, high utilization efficiency of light can be realized. The light reflecting film can be formed of, for example, aluminum (Al).

  It is preferable that the flange portion 21 and the prism main body 22 are integrally formed of glass. However, the flange portion 21 and the prism main body 22 may be formed separately and joined. In that case, the material of the collar part 21 and the prism main body 22 may mutually differ.

  When the prism 20 is made of plastic, the prism 20 can be formed by, for example, an injection molding method. On the other hand, when the prism 20 is made of glass, it can be formed by a polishing method or a precision press method. Among them, it is particularly preferable to integrally form the prism 20 using a precision press method from the viewpoint of manufacturing cost and the like.

  Hereinafter, the manufacturing process of the prism 20 using the precision press method will be described with reference to FIGS.

  FIG. 6 is a cross-sectional view illustrating a configuration of a main part of a manufacturing apparatus 30 for manufacturing the prism 20.

  FIG. 7 is an exploded perspective view illustrating a configuration of a main part of the manufacturing apparatus 30.

  First, the structure of the manufacturing apparatus 30 is demonstrated, referring FIG.6 and FIG.7.

  The manufacturing apparatus 30 includes a pair of press plates 31 and 37 and dies 32 to 36. A heater 38 is embedded in the press machines 31 and 37, and the press machines 31 and 37 and the dies 32 to 36 are configured to be temperature adjustable.

  The dies 32 to 36 can be roughly classified into an upper die 32, a lower die 33 to 35, and a sleeve (body die) 36. In the manufacturing apparatus 30, the lower die is a first lower die 33 having a vertically-cut columnar shape that is obliquely cut, and a second lower die 34 having a vertically-cut columnar shape that is opposed to the first lower die 33, The first lower mold 33 and the second lower mold 34 are configured by a cylindrical third lower mold 35 into which the first lower mold 33 and the second lower mold 34 are fitted. However, the lower molds 33 to 35 may be integrally formed.

  The sleeve 36 is formed in a cylindrical shape so that the third lower die 35 and the columnar upper die 32 are slidably fitted. By this sleeve 36, the relative positional deviation between the upper mold 32 and the lower molds 33 to 35 is suppressed.

  The height of the sleeve 36 is set higher than the sum of the height of the upper mold 32 and the height of the third lower mold 35. The first lower mold 33, the second lower mold 34, and the third lower mold 35 are formed at the same height. For this reason, a gap is formed between the upper die 32 and the third lower die 35 when the press is completed.

  The dies 32 to 36 are preferably formed of a heat resistant material. For example, the dies 32 to 36 are preferably formed of WC, SiC, TiC, TiN, ceramics, or the like. Moreover, you may form the film | membrane (release film) which has high heat resistance on the surface of the metal mold | dies 32-36.

  The upper die 32 is attached to the first press board 31. On the other hand, the lower dies 33 to 35 are attached to the second press board 37. The first press board 31 and / or the second press board 37 are connected to a pressurizing device (for example, a servo motor, an air cylinder, an oil cylinder, etc.) not shown in FIG. The first press plate 31 and the second press plate 37 are configured to be relatively displaceable by the pressurizing device.

  Next, the manufacturing process of the prism 20 using the manufacturing apparatus 30 will be described.

  First, a base material (for example, glass preform) is inserted into the molds 32 to 36. The molds 32 to 36 and the base material are heated by the heater 38. The heating is performed, for example, until the base material temperature is close to the softening temperature of the base material. Thereafter, the base material is pressed by changing the relative positions of the upper die 32 and the lower dies 33 to 35 by a pressurizing device (not shown). The surface of the prism body 22 is formed by the lower molds 33 to 35. On the other hand, the peripheral portion (protruding portion) of the collar portion 21 is formed by the lower dies 33 to 35, the upper die 32, and the sleeve 36.

  After pressing, the prisms 20 can be completed by slowly cooling (annealing) the dies 32 to 36 to a predetermined temperature.

(Embodiment 2)
In the first embodiment, the imaging apparatus 1 using the prism module 2 has been described. However, the prism module 2 can be used for an optical apparatus other than the imaging apparatus. For example, it can be used for a lighting device. In the second embodiment, the configuration of the illumination device 3 including the prism module 2 will be described with reference to FIG. In the description of the second embodiment, FIGS. 2 to 5 are referred to in common with the first embodiment. In addition, components having substantially the same function are described with reference numerals common to the first embodiment, and description thereof is omitted.

  FIG. 8 is a diagram illustrating a configuration of a main part of the illumination device 3 according to the second embodiment.

  The illumination device 3 according to Embodiment 2 includes a light source 41 and an illumination optical system including lens groups 42 to 44 (a first lens group 42, a second lens group 43, and a third lens group 44); The prism module 2 is disposed so that the prism 20 is positioned in the optical path of the illumination optical system. In the first embodiment, the light transmitting surface 22a is disposed so as to face the first lens group 14, whereas in the second embodiment, the light transmitting surface 22a faces the second lens group 43. Are arranged to be.

  The light source 41 is, for example, a light source that emits parallel light or diffused light. The light emitted from the light source 41 passes through the first lens group 42 and the second lens group 43 and enters the prism module 2. The light incident on the prism module 2 is reflected by the light reflecting surface 22c and is emitted from the prism module 2 (specifically, from the light transmitting surface 22a). The light emitted from the prism module 2 is transmitted through the third lens group 44 and emitted from the illumination device 3.

  As described in the first embodiment, the prism 20 can be easily attached with high accuracy. Therefore, a high-quality lighting device 3 can be realized.

  As described above, the optical element according to the present invention is useful for a digital still camera (DSC), a digital video camera (DVC), a mobile phone camera, a projection television, and the like.

1 is a diagram illustrating a configuration of a main part of an imaging apparatus 1 according to Embodiment 1. FIG. 2 is a perspective view of a prism module (optical element module) 2. FIG. 2 is a perspective view of a prism 20. FIG. FIG. 4 is a cross-sectional view of a portion cut out along a cut line IV-IV in FIG. 3. It is sectional drawing of the part cut out by the cutting line VV in FIG. 3 is a cross-sectional view of a manufacturing apparatus 30 for manufacturing the prism 20. FIG. 3 is an exploded perspective view of the manufacturing apparatus 30. FIG. It is a figure showing the structure of the principal part of the illuminating device 3 which concerns on Embodiment 2. FIG.

Explanation of symbols

1 Imaging device
2 Prism module
3 Lighting equipment
11 Light receiving element
12-14, 42-44 lens group
15 Prism folder
15a, 15b Plate-shaped body
15c, 15d plane part
15e, 15f Curved surface
16 lenses
20 Prism
21 Buttocks
22 Prism body
22a, 22b Light transmission surface
22c Light reflecting surface
22d, 22e end face
30 Manufacturing equipment
31, 37 press machine
32 Upper mold
33-35 Lower mold
36 sleeve
38 Heater
41 Light source

Claims (13)

A polygonal column main body having two light transmission surfaces and a light reflection surface formed on the side surface;
A collar portion formed so as to protrude outward from both end surfaces of the element body at an end portion near one surface of the two light transmission surfaces;
Optical element with The optical element according to claim 1,
An optical element in which the element body is formed in a curved shape so that the both end faces constitute a part of a cylindrical peripheral surface. The optical element according to claim 2,
The cylinder has an optical element having a central axis extending in a normal direction of one surface of the two light transmission surfaces. The optical element according to claim 1,
An optical element in which at least one of the two light transmission surfaces is formed as a spherical surface or an aspherical surface. The optical element according to claim 1,
An optical element further comprising a light reflecting film formed on the light reflecting surface. The optical element according to claim 1,
An optical element having a light reflectance of 90% or more on the light reflection surface of visible light incident perpendicularly to the element body from one surface of the two light transmission surfaces. The optical element according to claim 1,
The element body is an optical element made of glass. The optical element according to claim 1,
The element body is an optical element having a refractive index with respect to d-line of 1.65 or more. A folder with an opening, and
It is formed in a polygonal column shape having two light transmission surfaces and a light reflection surface as side surfaces, and the element main body inserted into the opening and the element at one end of the two light transmission surfaces near one surface An optical element that is formed so as to protrude outward from both end faces of the main body, and has a flange that contacts the folder;
An optical element module. An optical element module including a folder having an opening and an optical element;
The optical element is formed in a polygonal column shape having two light transmission surfaces and a light reflection surface as side surfaces, and is close to one surface of the element main body inserted into the opening and the two light transmission surfaces. An optical device comprising: a flange portion formed at an end portion so as to protrude outward from both end faces of the element body, and abutting against the folder. The optical device according to claim 10, wherein
A light receiving element;
An imaging optical system for forming an optical image of a subject on the light receiving surface of the light receiving element;
With
An optical apparatus in which the optical element is disposed in an optical path of the imaging optical system. The optical device according to claim 10, wherein
A light source;
An illumination optical system for irradiating an object to be illuminated with illumination light emitted from the light source;
With
An optical apparatus in which the optical element is disposed in an optical path of the illumination optical system. A polygonal column main body having two light transmission surfaces and a light reflection surface formed on the side surfaces, and projecting outward from both end surfaces of the element main body at an end portion near one surface of the two light transmission surfaces A method for manufacturing an optical element having a collar portion formed as follows,
A method for producing an optical element, wherein the optical element is obtained by heating and pressing a base material.

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