JP2005134832A - Imaging unit and equipment for image pickup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging unit capable of switching a prism unit to a 1st position and a 2nd position in accordance with the image pickup distance of a subject. <P>SOLUTION: The imaging unit 10 is equipped with the prism unit 30, an imaging device 12, a fixing member 13, a case member 14, a lever member (supporting member) 15, and a switching member 16 and a coupling spring 17 (switching mechanism). The unit 30 has at least two reflection surfaces formed as free curved surfaces. The lever member 15 supports the unit 30 movably within a specified movable range in an X direction. The switching member 16 selectively moves the unit 30 interlocked with the lever member 15 to the 1st position where the unit 30 is made to abut on the fixing member 13 and the 2nd position where the unit 30 is made to abut on the case member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image pickup apparatus used for a digital camera, a camera-equipped mobile phone, and the like, and more particularly, to an image pickup apparatus using a prism using a free-form surface as a reflection surface and an image pickup apparatus using the same.

  In recent years, a large number of imaging apparatuses using a coaxial optical system have been filed as imaging apparatuses used for digital cameras and camera-equipped mobile phones. The coaxial system is an optical system in which optical elements such as lenses are provided in a rotationally symmetrical manner with respect to the optical axis of the optical system (the axis connecting the aperture of the imaging system and the center of the imaging screen). A coaxial imaging device is disclosed in, for example, the following Patent Documents 1 to 3.

  Recent digital cameras and camera-equipped mobile phones are required to be smaller, thinner, and higher in performance. In an imaging apparatus using a coaxial optical system for these devices, the size of the imaging apparatus is required. To make the lens compact, it is necessary to reduce the number of lenses. However, if the number of lenses is reduced, it becomes difficult to reduce the aberration generated in the optical system, and the image quality deteriorates. Further, when trying to improve the image quality, it is necessary to increase the number of lenses, and as a result, there arises a problem that the image pickup apparatus becomes large.

  As one means for solving these problems, an imaging apparatus using a decentered optical system has been proposed. For example, Patent Documents 4 to 6 below describe an imaging apparatus using an imaging optical system using a prism using a free-form surface or the like.

  The aim of the techniques described in Patent Documents 4 to 6 is to form an imaging optical system using a prism, and use a free-form surface for the light incident surface, light exit surface, or reflecting surface of the prism. Thus, a compact and high-quality image can be obtained. In particular, in Patent Document 5 (Japanese Patent Laid-Open No. 2002-196243) and Patent Document 6 (Japanese Patent Laid-Open No. 2003-84200), two light prisms are combined, and the light incident surface of the first prism closer to the object, It is described that free curved surfaces are used for all seven surfaces in total, that is, the light incident surface, the two reflective surfaces, and the light exit surface of the second prism closer to the reflective surface, the light exit surface, and the imaging surface.

As a feature of such an optical system,
(1) The three reflecting surfaces use free-form surfaces having power (refractive power), but these reflecting surfaces can obtain a large power with respect to a refractive optical system such as a lens, and at the same time, chromatic aberration. Not affected.

(2) It can have seven optical surfaces in a compact space. Accordingly, the optical elements can be condensed and set in a limited space.

(3) Although it is desirable to increase the optical path length of the entire optical system to some extent in order to improve the optical performance, by using such a prism optical system, the optical path is bent, but the entire optical path length is long. The size of can be made compact.
For the above reasons, it is possible to improve image quality while being compact.

The optical system described in Japanese Patent Laid-Open No. 7-333505 includes a reflecting mirror, an optical system using a lens, and a reflecting mirror in order from the subject side. Since the optical system described in FIG. 6 can reduce the lateral width, a more compact imaging device can be provided.
JP 2001-272587 A Japanese Patent Laid-Open No. 2002-267928 JP 2002-120122 A JP-A-11-126766 JP 2002-196243 A JP 2003-84200 A

  When the imaging device is used in a small and thin digital camera or a camera-equipped mobile phone, the angle of view of the imaging optical system is set to a wide-angle system, and pan-focus (in the entire subject distance range while being a fixed focus) A method of setting the focus to be in general focus) can be considered.

  Further, as a recent trend, there is a need to read a bar code using a digital camera or a camera-equipped mobile phone equipped with this imaging device, or to read characters such as a book or a document. In order to meet these needs, the pan-focus imaging device needs a mechanism suitable for macro photography, but the above-mentioned Patent Documents 1 to 6 do not describe this technology.

  In addition, when mass-producing such an imaging device, the imaging surface of the imaging device for reading an image due to individual dimensional variations, characteristic variations, assembly variations, etc. of the optical system and optical system holding frame components It is difficult to accurately form a subject image.

  In order to solve this problem, it is necessary to perform focus surface adjustment (hereinafter referred to as fc adjustment) so that the relationship between the position of the incident surface of the image sensor and the imaging surface is the best for each imaging device. However, the fc adjustment mechanism suitable for such an imaging apparatus is not described in Patent Documents 1 to 6. Also, there is no disclosure of means for realizing both the mechanism suitable for macro photography and the fc adjustment mechanism with a small number of parts.

  Accordingly, an object of the present invention is to switch an prism unit between the first position and the second position in accordance with the imaging distance of a subject, and more preferably an imaging apparatus capable of fc adjustment, and imaging using the imaging apparatus It is to provide equipment.

  An imaging apparatus according to the present invention includes a prism unit, an imaging element, a fixing member, a case member, a support member, a first contact portion, a second contact portion, a third contact portion, a fourth contact portion, and a switching mechanism. Is provided. The prism unit is a prism unit that forms an object image on an image formation surface when a light beam from an object is incident, and has at least two free-form reflecting surfaces, and the light beam from the object is incident on the prism unit. The incident optical axis and the exit optical axis that emits a light beam from the prism unit to the imaging surface are provided substantially parallel to each other with a predetermined interval. The image sensor is disposed on the imaging surface and converts an object image formed by the prism unit into an electrical signal. The fixing member positions and holds the image sensor. The case member is positioned and held with respect to the fixed member. The support member supports the prism unit so as to be movable within a predetermined movable range along a direction intersecting with the light receiving surface of the image sensor. The first abutting portion is provided on the fixing member, abuts on a part of the prism unit, and positions the prism unit at a first position closest to the imaging element in the movable range of the prism unit. To do. The second abutting portion is provided on the case member, abuts against a part of the prism unit, and places the prism unit at a second position farthest from the image sensor in the movable range of the prism unit. Position. The third abutting portion is provided in the prism unit and abuts on the first abutting portion to position and hold the prism unit at the first position. The fourth abutting portion is provided on the prism unit and abuts on the second abutting portion to position and hold the prism unit at the second position. The switching mechanism selectively moves the prism unit to the first position and the second position in conjunction with the support member.

  The first position is, for example, a standard imaging position for imaging corresponding to a case where the position of an object to be imaged is between a predetermined position and a nearly infinite position, and the second position is For example, it is a macro imaging position for performing imaging corresponding to the case where the position of the object to be imaged is closer to the predetermined position. In this specification, the standard imaging position means a position where the prism unit is set in a pan-focus imaging state in which the focus is almost the same with the same setting from a close range to infinity. The macro imaging position means a position where the prism unit is set in an imaging state in which a so-called close-up photography can be performed, in which a subject closer than the closest distance is focused.

  The support member is, for example, a lever member that is pivotally supported by a rotation shaft that is disposed at a predetermined position with respect to the fixed member, and the switching mechanism is configured to move the prism unit to the first unit by a manual operation, for example. A switching member for switching between a position and the second position.

  Further, in order to hold the prism unit at the first position and the second position with a simple mechanism, the switching member is pivotally supported on a rotation shaft disposed at a predetermined position with respect to the fixing member, The switching mechanism includes a connecting spring that connects the switching member and the lever member. The connecting spring has the switching member and the lever in a first stable posture that holds the prism unit in the first position and a second stable posture that holds the prism unit in the second position. Energize the member.

  In a preferred embodiment of the present invention, the prism unit has two prisms, and each prism has at least one free-form reflecting surface, a light incident surface having a refractive power, and a refractive power. And a diaphragm member between both prisms.

  Further, at least one of the third contact portion and the fourth contact portion is formed on a part of the diaphragm member.

  The first abutting portion and the third abutting portion each form a plane, and the prism unit is positioned and held by matching the respective planes. The second abutting portion and the fourth abutting portion each form a plane, and the prism unit is positioned and held in posture by matching the respective planes.

  In order to facilitate fine adjustment to match the planes of the first contact portion and the third contact portion, the second contact portion and the fourth contact portion, the first contact portion and the third contact portion. Either one of the planes formed by the contact portions is constituted by the tips of the protrusions provided at at least three locations. In addition, one of the planes formed by the second contact portion and the fourth contact portion is formed by tips of protrusions provided at at least three locations.

  In order to reduce the number of component parts of the imaging apparatus, for example, at least one of the third contact portion or the fourth contact portion is formed on a part of the prism constituting the prism unit.

  In order to finely adjust the imaging plane with respect to the light receiving surface of the image sensor at the first position, the fine adjustment mechanism for displacing the first position in a direction orthogonal to the light receiving surface of the image sensor is fixed. The first contact portion is provided between a member and the prism unit, and the first contact portion is provided in a part of the fine adjustment mechanism that contacts the third contact portion. In this case, preferably, the fine adjustment mechanism is inclined with respect to the light receiving surface of the image sensor and the inclined surface provided with the first contact portion, and the fine adjustment mechanism is disposed along the light receiving surface of the image sensor. And a guide mechanism that moves the inclined surface in a tilting direction, and finely adjusts the first position by moving the fine adjustment mechanism along the guide mechanism. And the positioning holding | maintenance part for positioning and holding the said fine adjustment mechanism in a predetermined position is provided. Alternatively, the fine adjustment mechanism has at least three inclined surfaces inclined at the same angle in the same direction, and the third contact portion has at least three protrusions that are in contact with the inclined surfaces.

  Another imaging device according to the present invention includes a prism unit, an imaging element, a fixing member, a support member, a first contact portion, a second contact portion, a third contact portion, a fourth contact portion, and a switching mechanism. Prepare. The prism unit is a prism unit that forms an object image on an image formation surface when a light beam from an object is incident, and has at least two free-form reflecting surfaces, and the light beam from the object is incident on the prism unit. The incident optical axis and the exit optical axis that emits a light beam from the prism unit to the imaging surface are provided substantially parallel to each other with a predetermined interval. The image sensor is disposed on the imaging surface and converts the object image formed by the prism unit into an electrical signal. The fixing member positions and holds the image sensor. The support member supports the prism unit so as to be movable within a predetermined movable range along a direction intersecting with the light receiving surface of the image sensor. The first abutting portion is provided on the fixing member, abuts on a part of the prism unit, and positions the prism unit at a first position closest to the imaging element in the movable range of the prism unit. To do. The second contact portion contacts a part of the prism unit, and positions the prism unit at a second position farthest from the image sensor in the movable range of the prism unit. The third abutting portion is provided on the prism unit and abuts on the first abutting portion to position and hold the prism unit at the first position. The fourth abutting portion is provided in the prism unit and abuts on the second abutting portion to position and hold the prism unit at the second position. The switching mechanism selectively moves the prism unit to the first position and the second position in conjunction with the support member.

  An imaging device according to the present invention includes the above-described imaging device, a processing unit that obtains image data by performing predetermined electrical processing on an electrical signal obtained by the imaging device, and an applied information recording unit Recording means for recording the image data from the processing means. An example of the imaging device is an electronic device with an imaging device including a digital camera or a camera-equipped mobile phone.

  According to the imaging device of the present invention, the prism unit is moved to the first position by bringing the first contact portion and the third contact portion into contact with each other in the direction orthogonal to the light receiving surface of the image sensor. The position of the prism unit can be selectively switched by positioning the prism unit at the second position by bringing the second contact part and the fourth contact part into contact with each other. Therefore, two focal positions can be set for the distance from the light receiving surface of the image sensor to the subject.

  The imaging apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 20 taking a camera as an example. As shown in FIG. 1, the digital camera 1 is provided with a release button 20, a flash 21, a finder optical system 22, an imaging optical system 23, and an image monitor 24 (see FIG. 2) facing the outside of the housing 2. . As shown in FIG. 2, the housing 2 includes an imaging device 10 that constitutes a main part of the imaging optical system 23, an image processing circuit 25 as a processing unit, a recording unit 26 as a recording unit, and the like. The image processing circuit 25 has a function of obtaining image data by performing predetermined electrical processing on the electrical signal obtained by the imaging device 10. The recording unit 26 functions as a recording unit for recording the image data from the image processing circuit 25 on the applied recording medium.

  The imaging apparatus 10 includes a prism unit 30 which is an example of a decentered optical system in which an incident optical axis λi and an outgoing optical axis λo are provided substantially parallel to each other with a predetermined interval, and an imaging element 12 mounted on a substrate 11. Including. An example of the prism unit 30 is shown in FIGS. The prism unit 30 includes a first prism 41, a second prism 42, and a diaphragm member 43. The imaging element 12 is an element that converts light such as a CCD into an electrical signal, and is disposed on the exit side of the prism unit 30. A cover glass 12 a is attached to the light receiving surface of the image sensor 12. An optical member such as a polarizing filter may be attached instead of the cover glass 12a.

  As shown in FIG. 3, the first prism 41 is an eccentric prism including an incident surface 51, a rotationally asymmetric reflecting surface 52, and an exit surface 53. As shown in FIG. 5, the exit surface 53 of the first prism 41 has a flat portion 53b formed flat in the outer region of the effective diameter portion 53a of the optical path. The flat surface portion 53b has two positioning portions 53c and 53d formed in a columnar shape and three projections 53e, 53f and 53g formed in a hemispherical shape. The positioning portions 53c and 53d are provided at positions outside the effective diameter portion 53a. In the present embodiment, as shown in FIGS. 4 and 5, the positioning portions 53 c and 53 d are arranged at symmetrical positions with a plane A <b> 1 crossing the effective diameter portion 53 a in the direction along the incident optical axis λi.

  The protrusions 53e and 53g are provided at positions outside the positioning portions 53c and 53d that sandwich the effective diameter portion 53a with respect to the surface A1. Therefore, when compared with the distance from the center position of the effective diameter portion 53a, the distance to the protrusions 53e and 53g is longer than the distance to the positioning portions 53c and 53d. The protruding portion 53f is provided outside the effective diameter portion 53a and inside the positioning portions 53c and 53d with respect to the surface A1. In the present embodiment, the surface A1 is provided at a position where it intersects the flat surface portion 53b. Thus, among the three protrusions, at least two protrusions are provided at positions that are longer (distant) than the distance to the positioning portion when compared with the distance from the center position of the effective diameter portion 53a.

  As shown in FIG. 3, the second prism 42 is an eccentric prism composed of an incident surface 61, a reflecting surface 62, a reflecting surface 63, and an exit surface 64. At least one of the reflecting surface 62 and the reflecting surface 63 is formed to be rotationally asymmetric. As shown in FIG. 6, the incident surface 61 of the second prism 42 has a flat surface portion 61b formed flat in the outer region of the effective diameter portion 61a of the optical path. The flat portion 61b has two positioning portions 61c and 61d formed in a columnar shape and three protrusions 61e, 61f and 61g formed in a hemispherical shape. The positioning portions 61c and 61d are provided at positions outside the effective diameter portion 61a. The positioning portions 61c and 61d are arranged at symmetrical positions across a plane A2 that crosses the effective diameter portion 61a along the emission optical axis λo.

  The protruding portions 61e and 61g are provided at positions outside the positioning portions 61c and 61d that sandwich the effective diameter portion 61a with respect to the surface A2. The protrusion 61f is provided on the outer side of the effective diameter part 61a and on the inner side of the positioning part 61c, 61d with respect to the surface A2. Further, the protrusions 61e, 61f, and 61g are disposed asymmetrically on the incident surface 61 with respect to the surface A2.

  As shown in FIGS. 7 to 9, the diaphragm member 43 is provided with an opening 62 a configured to match the effective diameter of the optical action surfaces of the two prisms 41 and 42. The diaphragm member 43 also functions as a holding member that maintains the relative positional relationship between the first prism 41 and the second prism 42. The diaphragm member 43 has flat portions 62b and 62c formed in a flat shape outside the opening 62a on both sides facing the opening 62a.

  Positioning and holding portions 62d, 62e, 62f, and 62g are formed on the flat portions 62b and 62c. These positioning holding portions 62d to 62g are arranged at positions corresponding to the positioning portions 53c, 53d, 61c, 61d of the first and second prisms 41, 42 in accordance with the shapes of the positioning portions 53c, 53c, 61c, 61d. It is formed as a through hole that can be fitted.

  An example of the thickness H of the diaphragm member 43 is designed to be H = 1.12 mm, and examples of the lengths t of the positioning portions of the first and second prisms 41 and 42 are each set to t = 0.55 mm. In this case, t / H = 0.49.

  In the prism unit 30 configured in this way, the first prism 41 is fitted from the flat portion 62b side of the diaphragm member 43 with the positioning portion 53c fitted into the positioning holding portion 62d and the positioning portion 53d fitted into the positioning holding portion 62e. Combine. As a result, the position of the first prism 41 with respect to the diaphragm member 43 is determined. At this time, the protrusions 53e, 53f, 53g of the first prism 41 abut against the flat surface portion 62b of the diaphragm member 43, whereby the inclination of the first prism 41 with respect to the diaphragm member 43 is determined.

  Similarly, with respect to the second prism 42, the positioning portion 61c is fitted to the positioning holding portion 62f and the positioning portion 61d is fitted to the positioning holding portion 62g from the flat portion 62c side of the diaphragm member 43. Thereby, the position of the second prism with respect to the diaphragm member 43 is determined. At this time, the protrusions 61 e, 61 f, 61 g of the second prism 42 come into contact with the flat portion 62 c of the diaphragm member 43, whereby the inclination of the second prism 42 with respect to the diaphragm member 43 is determined.

  In this way, the first prism 41 and the second prism 42 are held on both sides of the diaphragm member 43 as shown in FIG. As shown in FIG. 11, one positioning holding portion 62 d is arranged so that the straight line passing through the center of gravity of the first prism 41 and the straight line passing through the center of gravity of the second prism 42 do not come on the same straight line on the diaphragm member 43. 62e and the other positioning holding portions 62f, 62g are provided at different positions.

  In the state of FIG. 10, when it is necessary to adjust the inclination of the first and second prisms 41 and 42 with respect to the diaphragm member 43, the protrusions 53 e, 53 f, 53 f, 53 f, 53 f, 53 f, The inclinations of the first prism 41 and the second prism 42 can be easily adjusted by cutting the protrusions 61e, 61f, 61g of the second prism 42 by a predetermined amount.

  As described above, the prism unit 30 of this embodiment has at least two free-form reflecting surfaces 52, 62, and 63. Moreover, the prism optical system in which the incident optical axis λi on which the light beam from the object surface is incident and the exit optical axis λo that emits the light beam from the prism unit 30 to the imaging surface 45 are provided substantially parallel to each other with a predetermined distance therebetween. It is constituted by. By being configured in this way, the prism unit 30 of the present embodiment forms an object image on the image plane 45 by the incidence of a light beam from the object.

  Next, the mechanism of the imaging apparatus 10 that moves the prism unit 30 described above in a direction intersecting the light receiving surface of the imaging element 12, preferably in a direction orthogonal thereto will be described with reference to FIGS. . For convenience, in each figure, the direction orthogonal to the light receiving surface of the image sensor 12 is the X direction, and the direction in which the first prism 41 and the second prism 42 are aligned is the direction orthogonal to the Y direction, the X direction, and the Y direction. Is the Z direction. As shown in FIG. 12, the imaging device 10 includes a fixing member 13, a case member 14, a lever member 15, a switching member 16, and a connecting spring 17 in addition to the prism unit 30 and the imaging element 12 described above.

  The fixing member 13 is disposed between the prism unit 30 and the image sensor 12. A window 13 a is provided at the center of the fixing member 13. The fixing member 13 receives light from the image sensor 12 on the emission optical axis λo so that the light beam emitted from the second prism 42 of the prism unit 30 passes through the window 13a and forms an image on the light receiving surface of the image sensor 12. Position and hold the surface. The fixing member 13 on the side facing the prism unit 30 is provided with a first contact portion 13 b that contacts a part of the prism unit 30.

  As shown in FIG. 13, the case member 14 covers the prism unit 30 and is fixed to the fixing member 13. The case member 14 is provided with an incident window 14 a at a portion through which a light beam incident on the first prism 41 of the prism unit 30 passes. A protective glass 14b is fitted into the incident window 14a. An IR cut glass may be used as the protective glass 14b. A second contact portion 14 c that contacts a part of the prism unit 30 is provided on the inner side of the case member 14 on the side facing the prism unit 30.

  The diaphragm member 43 of the prism unit 30 is provided in parallel with the planes A1 and A2 through which the incident optical axis λi and the outgoing optical axis λo pass, and sandwiches the first prism 41 and the second prism 42 from both sides as shown in FIG. A guide plate 31 is provided as described above. The guide plate 31 may be formed integrally with the diaphragm member 43 or may be attached as a separate part. As shown in FIG. 15, the guide plate 31 is in sliding contact with the inner surface of the case member 14, and has a Y direction in which the first prism 41 and the second prism 42 are arranged and an X direction orthogonal to the light receiving surface of the image sensor 12. The prism unit 30 is prevented from being displaced in the width direction (Z direction) of the prism unit 30 that crosses each other.

  The guide plate 31 has a boss 31a formed in a cylindrical shape extending in a direction along the flat portions 62b and 62c of the diaphragm member 43. A support pin 32 that pivotably connects to the prism unit 30 and the lever member 15 is attached to the boss 31a. Therefore, the case member 14 is formed with a slit 14d through which the boss 31a and the support pin 32 pass.

  At four corners of the guide plate 31 facing the fixing member 13, protrusions that bulge toward the fixing member 13 are formed. The tip of this protrusion constitutes a third contact part 31b that positions the prism unit 30 at the first position P1 closest to the image pickup device 12 by contacting the first contact part 13b. As described above, the first contact portion 13b and the third contact portion 31b form a flat surface, and the prism unit 30 is positioned at the first position P1 by matching the respective flat surfaces.

  Further, at the four corners of the guide plate 31 facing the case member 14, convex portions that bulge toward the second contact portion 14 c are formed. The tip of this protrusion constitutes a fourth contact portion 31c that positions the prism unit 30 at the second position P2 farthest from the image sensor 12 by contacting the second contact portion 14c. As described above, the second contact portion 14c and the fourth contact portion 31c form a flat surface, and the prism unit 30 is positioned at the second position P2 by matching the respective flat surfaces.

  In the present embodiment, the third contact portion 31b and the fourth contact portion 31c are illustrated as planes constituted by the tips of the protrusions, but the first contact portion 13b and the second contact portion are respectively illustrated. You may provide in the shape corresponding to the contact part 14c. Further, the third contact portion 31b and the fourth contact portion 31c are formed on a plane, and the first contact portion 13b and the second contact portion 14c are respectively formed as the third contact portion 31b and the fourth contact portion 31c. You may provide as a protrusion by which a front-end | tip part is arrange | positioned on the plane corresponding to.

  The lever member 15 is disposed on both outer sides of the case member 14 along the Y direction in which the first prism 41 and the second prism 42 are arranged. The lever member 15 has a base end portion 15a pivotally supported on a rotation axis R1 attached to a corner portion of the case member 14 on the second prism unit side. The rotation axis R1 is disposed in parallel with the extending direction of the boss 31a and the support pin 32. The lever member 15 rotates about the rotation axis R <b> 1 to move the prism unit 30 connected by the support pins 32 in a direction intersecting with the light receiving surface of the image sensor 12, preferably in a direction orthogonal thereto. Thus, the lever member 15 functions as a support member that supports the prism unit 30 so as to be movable within a predetermined movable range along the direction intersecting the light receiving surface of the image sensor 12.

  The switching member 16 has a base end 16a pivotally supported on the rotation axis R1 coaxially with the base end portion 15a of the lever member 15. The distal end 15b of the lever member 15 and the distal end 16b of the switching member 16 that are separated from the rotation axis R1 in the radial direction are coupled by a coupling spring 17. The tip 16b of the switching member 16 is provided at a position closer to the rotation axis R1 than the tip 15b of the lever member 15. Thereby, the tip 15b of the lever member 15 and the tip 16b of the switching member 16 do not interfere with the connecting spring 17 and the spring bridges 18a and 18b that rotatably support the connecting spring 17 at the respective tips 15b and 16b. You can pass each other.

  The connecting spring 17 biases the tip 15b of the lever member 15 and the tip 16b of the switching member 16 in a direction away from each other. Therefore, as shown in FIG. 17, when the tip end 16 b of the switching member 16 is rotated to a position farther from the imaging element 12 and the fixing member 13 than the tip end 15 b of the lever member 15, the lever member 15 approaches the fixing member 13. It becomes 1st stable attitude | position S1 maintained in the state biased to the direction. As shown in FIG. 18, when the tip 16 b of the switching member 16 is rotated to a position closer to the image sensor 12 and the fixing member 13 than the tip 15 b of the lever member 15, the lever member 15 is moved to the image sensor 12 and the fixing member. The second stable posture S <b> 2 is maintained in the state of being biased in the direction away from 13.

  Since the prism unit 30 is connected to the lever member 15 by the support pin 32, the prism unit 30 is also moved in the X direction as the lever member 15 rotates. Therefore, in the state of the first stable posture, the prism unit 30 is urged toward the fixing member 13 as shown in FIG. 19, and the third contact portion 31b contacts the first contact portion 13b. It is positioned at the first position P1 that is closest to the image sensor 12 within the movable range. Then, in the state of the second stable posture, the prism unit 30 is urged toward the case member 14 as shown in FIG. 20, and the fourth contact portion 31c contacts the second contact portion 14c. It is positioned at the second position P2 farthest from the image sensor 12 within the movable range.

  As described above, the switching member 16 and the coupling spring 17 are interlocked with the lever member 15 that is the support member, and take the first stable posture S1 and the second stable posture S2, thereby making the prism unit 30 the first stable posture. It functions as a switching mechanism for selectively positioning by moving to the position P1 and the second position P2.

  In order to switch to the two focus settings of the first position P1 and the second position P2, the imaging device 10 causes the third contact portion 31b to contact the first contact portion 13b to place the prism unit 30 in the first position. The prism unit 30 is positioned at the second position P2 by positioning the first abutting position P1 and bringing the fourth abutting portion 31c into contact with the second abutting portion 14c. Therefore, in order to move the prism unit 30, a special mechanism for moving the prism unit 30 so that the optical axis is not shifted is unnecessary, and the structure of the imaging device 10 can be simplified.

  Further, since the prism unit 30 is biased to the fixing member 13 at the first position P1 and to the case member 14 at the second position P2 by the connecting spring 17, the prism unit 30 does not rattle. The first position P1 and the second position P2 are reliably maintained.

  Since the third contact portion and the fourth contact portion are configured by the tips of the protrusions, the positioning error of the prism unit 30 within the manufacturing tolerance that occurs when the imaging device 10 is mass-produced is It can be easily corrected by adjusting the height.

  As shown in FIG. 2, in the present embodiment, the first position P1 is a standard imaging position, for example, and the second position P2 is a macro imaging position, for example. The switching member 16 is interlocked with the manual operation switching member 95 exposed from the housing 2 of the digital camera 1 shown in FIG. 1, and the manual operation switching member 95 is operated, whereby the first stable posture S1 and the second stable posture S1. It switches to the stable posture S2. Therefore, by operating the manual operation switching member 95, the prism unit 30 is selectively switched between the first position P1 and the second position P2, and two focus positions can be set. Further, the switching member 16 may be electrically switched using an actuator such as an electric motor instead of a manual operation.

  In the present embodiment, the third contact part 31b and the fourth contact part 31c are both formed on the guide plate 31 provided on the diaphragm member 43, but may be provided on the diaphragm member 43, It may be provided in a part of the first prism 41 and the second prism 42, or may be provided across the first prism 41, the second prism 42, and the diaphragm member 43. Further, instead of providing the case member 14, a bracket including a second contact portion that contacts the fourth contact portion 31 c of the prism unit 30 at the second position P <b> 2 may be extended from the fixing member 13.

  Next, an imaging apparatus 10 according to a second embodiment of the present invention will be described with reference to FIGS. The imaging apparatus 10a of the present embodiment is different from the imaging apparatus 10 of the first embodiment in that a fine adjustment mechanism 70 is further provided. Therefore, since the configuration not related to the fine adjustment mechanism 70 is the same as that of the first embodiment, the components having the same functions are denoted by the same reference numerals and the description thereof is omitted.

  As shown in FIG. 21, the fine adjustment mechanism 70 is mounted between the fixing member 13 and the prism unit 30. As shown in FIGS. 24 to 26, the fine adjustment mechanism 70 is provided so as to be movable in the Y direction in which the first prism 41 and the second prism 42 are arranged. The fixed member 13 is formed with a guide portion 13e that protrudes toward the first prism 41 along the Y direction. The distal end portion 71 of the fine adjustment mechanism 70 on the first prism 41 side is passed between the guide portion 13 e and the substrate 11. Further, the base end portion 72 of the fine adjustment mechanism 70 on the second prism 42 side is exposed to the outside of the case member 14 as shown in FIGS.

  The fine adjustment mechanism 70 includes an adjustment unit 73 extending along the Y direction. As shown in FIGS. 22 and 23, the adjustment unit 73 is disposed on both sides of the window 13a, and is provided so as to pass through the inside of the case member 14 with the portion near the fixing member 13 of the prism unit 30 interposed therebetween. . As shown in FIG. 21, the adjustment portion 73 has slopes 73 a at positions corresponding to the third contact portions provided at the four corners of the guide plate 31 on the fixing member 13 side. The slope 73a includes a first contact portion 73b. Further, the slope 73 a is formed with the same gradient in the moving direction of the fine adjustment mechanism 70.

  As shown in FIGS. 24 to 26, the imaging apparatus 10a including the fine adjustment mechanism 70 configured as described above has a prism in the first stable posture S1 in which the prism unit 30 is positioned at the first position P1. The third contact portion 31 b provided in the unit 30 is brought into contact with the first contact portion 73 b provided in the fine adjustment mechanism 70. In this state, when the adjustment mechanism is moved from the state of FIG. 24 to the state of FIG. 25 or from the state of FIG. 24 to the state of FIG. 26, the light receiving surface of the image sensor 12 is an amount (distance) corresponding to the slope of the inclined surface 73a. Displacement along the X direction orthogonal to

  In the present embodiment, since the inclined surface 73a is inclined toward the first prism 41, the prism unit 30 is displaced in a direction approaching the image pickup device 12 by moving from the state of FIG. 24 to the state of FIG. . Also, by moving the fine adjustment mechanism 70 from the state of FIG. 24 to the state of FIG. 26, the prism unit 30 is displaced in a direction away from the image sensor 12.

  As described above, in the imaging device 10a including the fine adjustment mechanism 70, the position of the prism unit 30 is the first position P1 where the third contact portion 31b of the prism unit 30 contacts the first contact portion 73b of the fine adjustment mechanism 70. Adjustment, that is, fine adjustment of the focus surface (fc adjustment). After the fc adjustment, the fine adjustment mechanism 70 is fixed between the distal end portion 71 and the guide portion 13e, and the proximal end portion 72 and the fixing member 13 or the case member 14 by adhesive or laser melting.

  In the first and second embodiments, the third contact portion 31b and the fourth contact portion 31c are provided at four locations, respectively, but if at least three are provided, imaging is performed. The posture of the prism unit 30 can be set to a desired angle with respect to the light receiving surface of the element. Therefore, in the second embodiment, it is only necessary that at least three inclined surfaces 73a of the fine adjustment mechanism 70 corresponding to the third contact portion 31b are provided.

  As an example of an imaging device according to the present invention, an example in which an imaging device is incorporated in a camera-equipped mobile phone 160 is shown in FIG. By incorporating the image pickup apparatus (for example, the image pickup apparatus 10) described in each of the embodiments into the camera-equipped mobile phone 160, the camera-equipped mobile phone 160 can be reduced in size and thickness, and the image quality can be improved.

  28 to 30 show different examples of the prism units 30a, 30b, and 30c applied to the imaging device of the present invention. Any of the prism units 30a, 30b, and 30c can be switched between the first position P1 and the second position P2 by a switching mechanism similar to that of the imaging device of the above-described embodiment.

  In the prism unit 30a shown in FIG. 28, the surfaces 201 to 206 of the first prism 41a and the second prism 42a are all free-form surfaces. The light incident from the first surface 201 is refracted by the first surface 201, totally reflected by the second surface 202, refracted by the third surface 203, and then refracted by the fourth surface 204. Further, the light is totally reflected by the fifth surface 205, then totally reflected by the sixth surface 206, refracted by the fifth surface 205, and then imaged on the imaging surface 45.

  The eccentric prism 210 of the prism unit 30b shown in FIG. 29 has a first surface 211, a second surface 212, and a third surface 213 that are free-form surfaces. The light incident through the diaphragm member 214 is refracted by the first surface 211 and incident on the eccentric prism 210, is internally reflected by the second surface 212, is incident again on the first surface 211, and is totally reflected this time. Internally reflected by the third surface 213, totally reflected by the first surface 211 three times, again internally reflected by the third surface 213, refracted by the first surface 211 and imaged by the imaging surface 45 four times. To do.

  In the prism unit 30c shown in FIG. 30, the surfaces 231 to 238 of the first prism 221 and the second prism 222 are all free-form surfaces. The light incident from the first surface 231 is refracted by the first surface 231, totally reflected by the second surface 232, further totally reflected by the third surface 233, and then refracted by the fourth surface 234 and the fifth surface 235. Further, after being totally reflected by the sixth surface 236 and the seventh surface 237, it is refracted by the eighth surface 238 and forms an image on the imaging surface 45.

  Needless to say, in implementing the present invention, various components of the invention, such as a prism optical system, a guide mechanism, an image pickup device, and a switching mechanism, can be changed without departing from the scope of the invention.

  In the above embodiment, the switching member 16 of the switching mechanism is switched between the first stable posture S1 and the second stable posture S2 by the manual operation switching member 95, but instead of using the manual operation switching member 95, the motor Alternatively, it may be configured to be switched electrically by using an actuator such as a solenoid.

1 is a perspective view of a digital camera provided with an imaging apparatus according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the inside of the digital camera shown in FIG. 1. The side view of the prism unit of the digital camera shown by FIG. FIG. 4 is an exploded perspective view of the prism unit shown in FIG. 3. FIG. 4 is a perspective view of a first prism of the prism unit shown in FIG. 3. FIG. 4 is a perspective view of a second prism of the prism unit shown in FIG. 3. FIG. 4 is a perspective view of a diaphragm member of the prism unit shown in FIG. 3. FIG. 4 is a front view of a diaphragm member of the prism unit shown in FIG. 3. FIG. 4 is a rear view of a diaphragm member of the prism unit shown in FIG. 3. FIG. 4 is a perspective view of the prism unit shown in FIG. 3. FIG. 4 is a side view of a first prism and a second prism of the prism unit shown in FIG. 3. FIG. 2 is an exploded perspective view of an imaging device built in the digital camera shown in FIG. 1. The perspective view of the imaging device shown by FIG. The perspective view which shows the state which removed the case member of the imaging device shown by FIG. FIG. 14 is a plan view showing a state in which the imaging device shown in FIG. FIG. 14 is a side view showing a state in which the imaging device shown in FIG. The side view which shows the 1st stable attitude | position of the imaging device shown by FIG. FIG. 14 is a side view showing a second stable posture of the imaging device shown in FIG. 13. FIG. 18 is a cross-sectional view of the imaging device shown in FIG. 17. FIG. 19 is a cross-sectional view of the imaging apparatus shown in FIG. The disassembled perspective view which shows the imaging device of 2nd Embodiment which concerns on this invention. The top view which shows the state seen from the entrance side of the imaging device shown by FIG. FIG. 22 is a side view showing a state in which the imaging device shown in FIG. 21 is viewed from the second prism side with a part cut away. FIG. 22 is a cross-sectional view along the direction in which the prisms of the image pickup apparatus shown in FIG. 21 are arranged. FIG. 25 is a cross-sectional view of the imaging apparatus showing a state where the fine adjustment mechanism is moved to the second prism side from the state of FIG. 24. FIG. 25 is a cross-sectional view of the imaging apparatus showing a state where the fine adjustment mechanism is moved to the first prism side from the state of FIG. 24. The perspective view which shows the mobile phone with a camera as another example of the imaging device which concerns on this invention. Sectional drawing which shows the other example of a prism optical system typically. Sectional drawing which shows the further another example of a prism optical system typically. Sectional drawing which shows the further another example of a prism optical system typically.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Digital camera (imaging apparatus) 10, 10a ... Imaging device, 12 ... Imaging element, 13 ... Fixing member, 13b ... 1st contact part, 13e ... Guide part (guide mechanism), 14 ... Case member, 14c ... 2nd contact part, 15 ... Lever member (support member), 16 ... Switching member (switching mechanism), 17 ... Connection spring (switching mechanism), 30, 30a, 30b, 30c ... Prism unit, 31b ... 3rd contact Contact part, 31c ... 4th contact part, 41, 41a ... 1st prism, 42, 42a ... 2nd prism, 43 ... Diaphragm member, 70 ... Fine adjustment mechanism, 73a ... Slope, 73b ... 1st contact part, 95 ... manual operation switching unit, 160 ... mobile phone with camera, λi ... incident optical axis, λo ... reflected optical axis, P1 ... first position, P2 ... second position, S1 ... first stable posture, S2 ... second Stable posture, R1 ... rotation axis.

Claims (17)

A prism unit that forms an object image on an imaging surface when a light beam from an object is incident, and has at least two free-form reflecting surfaces, and an incident optical axis on which the light beam from the object is incident A prism unit that is provided substantially parallel to each other with an emission optical axis that emits a light beam from the prism unit to an imaging plane;
An image sensor for converting an object image formed by the prism unit into an electric signal disposed on the imaging plane;
A fixing member for positioning and holding the imaging element;
A case member positioned and held with respect to the fixed member;
A support member that supports the prism unit movably within a predetermined movable range along a direction intersecting the light receiving surface of the image sensor;
A first abutting portion that is provided on the fixing member and abuts against a part of the prism unit and positions the prism unit at a first position closest to the image sensor in the movable range of the prism unit; ,
A second abutting portion that is provided on the case member and abuts against a part of the prism unit and positions the prism unit at a second position farthest from the image sensor in the movable range of the prism unit. When,
A third abutting portion provided in the prism unit, abutting on the first abutting portion, and positioning and holding the prism unit at the first position;
A fourth abutting portion provided on the prism unit, abutting on the second abutting portion, and positioning and holding the prism unit at the second position;
An image pickup apparatus comprising: a switching mechanism that selectively moves the prism unit to the first position and the second position in conjunction with the support member. Processing means for performing predetermined electrical processing on an electrical signal obtained by the imaging apparatus according to claim 1 to obtain image data;
A recording unit for recording the image data from the processing unit in an applied information recording unit;
An imaging apparatus comprising: The first position is a standard imaging position for imaging corresponding to a case where the position of an object to be imaged is between a predetermined position and a nearly infinite position,
The imaging apparatus according to claim 1, wherein the second position is a macro imaging position for performing imaging corresponding to a case where an object to be imaged is closer to the predetermined position. The support member is a lever member that is pivotally supported by a rotation shaft that is disposed at a predetermined position with respect to the fixed member.
The imaging apparatus according to claim 1, wherein the switching mechanism is a switching member for switching the prism unit between the first position and the second position by a manual operation. The switching member is pivotally supported by a rotating shaft arranged at a predetermined position with respect to the fixed member,
The switching mechanism has a connecting spring that connects the switching member and the lever member,
The connection spring includes a switching member, a lever member, and a lever member that are in a first stable posture for holding the prism unit in the first position and a second stable posture for holding the prism unit in the second position. The imaging apparatus according to claim 4, wherein the imaging apparatus is biased.   The prism unit has two prisms, and each prism has at least one free-form reflecting surface, a light incident surface having refractive power, and a light emitting surface having refractive power. The imaging apparatus according to claim 1, further comprising a diaphragm member between both prisms.   The imaging apparatus according to claim 6, wherein at least one of the third contact portion and the fourth contact portion is formed on a part of the diaphragm member.   The first contact portion and the third contact portion each form a plane, and the prism unit is positioned and held by matching the respective planes. Imaging device.   The said 2nd contact part and the said 4th contact part each form a plane, The positioning and attitude | position holding | maintenance of the said prism unit are performed by making each plane correspond. Imaging device.   9. The flat surface formed by each of the first contact portion and the third contact portion is formed by tip ends of protrusions provided at least at three locations. Imaging device.   10. The flat surface formed by each of the second contact portion and the fourth contact portion is formed by tip ends of protrusions provided at least at three locations. Imaging device.   The imaging apparatus according to claim 1, wherein at least one of the third contact portion or the fourth contact portion is formed on a part of a prism constituting the prism unit. A fine adjustment mechanism for displacing the first position in a direction orthogonal to the light receiving surface of the image sensor is provided between the fixing member and the prism unit;
The imaging apparatus according to claim 1, wherein the first contact portion is provided in a part of the fine adjustment mechanism that contacts the third contact portion. The fine adjustment mechanism is
An inclined surface provided with the first contact portion inclined with respect to the light receiving surface of the imaging element;
A guide mechanism for moving the fine adjustment mechanism along the light receiving surface of the image sensor in a direction in which the inclined surface is inclined;
The imaging apparatus according to claim 13, wherein the first position is finely adjusted by moving the fine adjustment mechanism along the guide mechanism.   The imaging apparatus according to claim 14, further comprising a positioning holding unit for positioning and holding the fine adjustment mechanism at a predetermined position.   The fine adjustment mechanism has at least three inclined surfaces inclined at the same angle in the same direction, and the third contact portion has at least three protrusions that are in contact with the inclined surfaces. The imaging device according to claim 14. A prism unit that forms an object image on an imaging surface when a light beam from an object is incident, and has at least two free-form reflecting surfaces, and an incident optical axis on which the light beam from the object is incident A prism unit that is provided substantially parallel to each other with an emission optical axis that emits a light beam from the prism unit to an imaging plane;
An image sensor disposed on the imaging plane for converting an object image formed by the prism unit into an electrical signal;
A fixing member for positioning and holding the imaging element;
A support member that supports the prism unit movably within a predetermined movable range along a direction intersecting the light receiving surface of the image sensor;
A first abutting portion that is provided on the fixing member and abuts against a part of the prism unit and positions the prism unit at a first position closest to the image sensor in the movable range of the prism unit; ,
A second abutting portion for abutting a part of the prism unit and for positioning the prism unit at a second position farthest from the image sensor in the movable range of the prism unit;
A third abutting portion provided in the prism unit, abutting on the first abutting portion, and positioning and holding the prism unit at the first position;
A fourth abutting portion provided on the prism unit, abutting on the second abutting portion, and positioning and holding the prism unit at the second position;
An image pickup apparatus comprising: a switching mechanism that selectively moves the prism unit to the first position and the second position in conjunction with the support member.

Images