JP2004054131A - Imaging lens device and method for adjusting the same, and imaging apparatus and method for adjusting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and adequately perform optical axis adjustment of a plurality of lenses by simplifying a structure. <P>SOLUTION: A rear lens barrel 5 is shifted in a direction approximately orthogonal to the optical axis relative to an intermediate lens barrel 4 in the state a zooming lens 13 is positioned at a wide angle end. While a pair of guide shafts 23a and 23b are being inclined relative to a front lens barrel 3, the optical axis of a focusing lens 18 is adjusted relative to a lens 14 fixed to the lens barrel 4 and thereafter the lens barrel 5 is fixed to the lens barrel 4. Also, the lens barrel 3 is shifted in the direction approximately orthogonal to the optical axis relative to the lens barrel 4 in the state the zooming lens 13 is positioned at a telephoto end. While a pair of the guide shafts 23a and 23b are inclined relative to the lens barrel 5, the optical axis of the lens 9 fixed to the lens barrel 3 is adjusted relative to the zooming lens 13. After the optical axes of the lens 9 fixed to the lens barrel 3 and the zooming lens 13 are adjusted relative to the lens 14 fixed to the lens barrel 4, the lens barrel 3 is fixed to the lens barrel 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides an imaging lens apparatus that forms an image of a subject by displacing some of the plurality of lenses arranged in a lens barrel body in the optical axis direction, an adjustment method thereof, and such an imaging method. The present invention relates to an image pickup apparatus that picks up an image of a subject formed by an image lens device using a solid-state image pickup device and a method of adjusting the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image of a subject is formed by displacing, in the optical axis direction, a part of a plurality of lenses arranged in a state where the optical axis is aligned with the lens barrel body in the lens barrel body. There is an imaging lens device for imaging. An image of a subject formed by such an imaging lens device is received by a solid-state imaging device such as a charge-coupled device (CCD) or a complementary mental-oxide semiconductor device (CMOS), and the solid-state imaging device receives the image. There is an imaging device such as a digital still camera and a digital video camera that photoelectrically converts the converted light and outputs it as an electric signal to generate digital image data corresponding to an image of a subject.
[0003]
For example, the imaging device 100 shown in FIG. 6 is a device in which the entire device is formed into a small package by attaching a solid-state image sensor or the like to the lens barrel main body constituting the above-described imaging lens device. , A plurality of lenses are arranged with their optical axes aligned.
[0004]
The plurality of lenses include, from the subject side, a fixed lens group 101, a movable lens group 102 for zooming, a fixed lens 103, and a movable lens group 104 for focusing, and the movable lens group 102 for zooming and the focus By moving the movable lens group 104 in the optical axis direction, zooming (magnification changing operation) and focusing (focus adjustment operation) are performed. .
[0005]
An iris unit 106 for adjusting the aperture 105 a of the diaphragm 105 is disposed between the fixed lens 103 and the movable lens group 104 for focusing. On the image plane of the subject formed by the plurality of lenses, an optical filter 107 in which an infrared cut filter 107a and a low-pass cut filter 107b are bonded, and an image of the subject formed by the plurality of lenses are provided. And a solid-state image pickup device 108 for picking up an image.
[0006]
In the imaging apparatus 100, the image plane of the object formed by the plurality of lenses and the light receiving plane of the solid-state imaging device 108 are performed while performing zooming (magnifying operation) for displacing the movable lens group 102 for zooming in the optical axis direction. Focusing (focus adjustment operation) of displacing the movable lens group 104 for focusing in the optical axis direction is performed so that the values of. Thus, the focal length can be continuously changed while keeping the image plane of the subject formed by the plurality of lenses and the light receiving surface of the solid-state imaging device 108 in agreement.
[0007]
For example, in the wide position shown in FIG. 7, the movable lens group 102 for zooming is positioned at the most front side (wide end), so that the image of the subject formed on the light receiving surface of the solid-state imaging device 108 has the widest angle ( Wide). On the other hand, in the tele-position shown in FIG. 8, by positioning the movable lens group 102 for zooming on the rearmost side (tele end), the image of the subject formed on the light receiving surface of the solid-state imaging device 108 is most telephoto ( Tele).
[0008]
In the image pickup apparatus 100, the image of the subject formed by the plurality of lenses is received by the solid-state imaging device 108, and the electric signal output from the solid-state imaging device 108 is processed to correspond to the image of the subject. Digital image data can be generated.
[0009]
[Problems to be solved by the invention]
By the way, in the above-described imaging device 100, the miniaturization of the entire device has been actively promoted in order to improve the convenience and ease of use in carrying. Accordingly, miniaturization of the above-described imaging lens device has been promoted, and in particular, a demand for miniaturization of the lens has been increasing. Further, downsizing of the solid-state imaging device 108 which is effective for downsizing of the lens is also being promoted. Furthermore, in order to improve the image quality and resolution of still images and the like, it is required to further miniaturize the pixels of the solid-state imaging device and to dramatically improve the imaging performance of the lens.
[0010]
However, in the above-described imaging apparatus 100, the sensitivity of each lens is increased due to the miniaturization of the lens, and the deterioration of the imaging performance due to the variation between the lenses is a serious problem. That is, in order to further reduce the size of the above-described imaging apparatus 100, it is necessary to improve the component accuracy and the positioning accuracy of each component, and to prevent the displacement (eccentricity) and inclination of the optical axes of a plurality of lenses. There is. In particular, it is difficult to dramatically improve the accuracy of the components of each component such as the lens and the lens barrel main body due to the manufacturing process capability, so the optical axis shift between the lenses when assembling the lens to the lens barrel main body. (Eccentricity) and inclination cause deterioration of the imaging performance.
[0011]
For this reason, conventionally, as a method of adjusting the eccentricity and the inclination between the fixed lens group and the movable lens group, for example, Japanese Patent Application Laid-Open Nos. 11-271587, 11-7051, and 9-95 No. 329737 has been proposed.
[0012]
However, in such a conventional optical axis adjustment method, it is necessary to provide a mechanism for performing shift adjustment of the fixed lens group, a structure for fixing the fixed lens group after the adjustment, and the like on the lens barrel main body. There is a problem that it is very difficult to reduce the size as a whole. In addition, when a new mechanism for performing such an optical axis adjustment is provided, not only the number of parts but also the number of man-hours are increased, so that there is a problem that the manufacturing cost increases. Further, in the above-described image pickup apparatus 100, even if the eccentricity and the tilt generated between the fixed lens 103 and the focus movable lens group 104 can be prevented by the conventional optical axis adjustment method, the fixed lens group It is difficult to prevent eccentricity and inclination occurring between the zoom lens 101 and the movable lens group 102 for zooming. Therefore, in order to guarantee sufficient imaging performance in the wide position, it is necessary to provide a new mechanism for adjusting the eccentricity and tilt between the fixed lens group 101 and the movable lens group 102 for zooming in the lens barrel main body. This causes a problem that it is very difficult to reduce the size of the entire device. Also, in this case, not only the number of parts but also the number of assembling steps increase, which causes a problem that the manufacturing cost increases.
[0013]
Accordingly, the present invention has been proposed in view of such a conventional situation, and further simplifies the structure and easily and appropriately adjusts the optical axes of a plurality of lenses, thereby further reducing the size and cost. It is an object of the present invention to provide an imaging lens device and a method of adjusting the imaging lens device that can be realized.
[0014]
Further, the present invention simplifies the structure and easily and appropriately adjusts the optical axes of a plurality of lenses, so that an image of a subject formed by a plurality of lenses can be appropriately captured by a solid-state imaging device. In addition, an object of the present invention is to provide an imaging apparatus and a method of adjusting the imaging apparatus, which can further reduce the size and cost.
[0015]
[Means for Solving the Problems]
In order to achieve this object, an imaging lens device according to the present invention includes a plurality of lenses for forming an image of a subject, and a plurality of lenses arranged with their optical axes coincident with each other. A lens barrel divided into a front barrel, an intermediate barrel, and a rear barrel in the front-rear direction, and a lens housed in the barrel body, both ends of which are supported by the front barrel and the rear barrel. A pair of guide shafts that support the zoom lens and the focus lens so as to be movable in the optical axis direction, and the front barrel and the rear barrel support both ends of the pair of guide shafts. It is characterized in that it can be relatively displaced in a direction substantially orthogonal to the optical axis with respect to the intermediate lens barrel fixed in the state in which it is fixed.
[0016]
As described above, in the imaging lens device according to the present invention, one of the front barrel and the rear barrel that supports both ends of the pair of guide shafts has the optical axis with respect to the intermediate barrel. By moving the zoom lens and the focusing lens together with the pair of guide shafts while tilting the pair of guide shafts with respect to the other lens barrel. The optical axes of a plurality of lenses can be adjusted without providing an adjustment mechanism or the like for adjusting the eccentricity and inclination of the lenses.
[0017]
Further, the adjusting method of the imaging lens device according to the present invention includes a plurality of lenses for forming an image of a subject, and a plurality of lenses arranged with their optical axes coincident with each other, at least in the front-back direction of the optical axis. A lens barrel body divided into a front lens barrel, an intermediate lens barrel, and a rear lens barrel, and both ends supported by the front lens barrel and the rear lens barrel, of the lenses housed in the lens barrel body. When performing the optical axis adjustment of the imaging lens device including a pair of guide shafts that support the zoom lens and the focus lens movably in the optical axis direction, the zoom lens is positioned at the wide end. In this state, the rear barrel is relatively shifted with respect to the intermediate barrel in a direction substantially perpendicular to the optical axis, and the optical axes of the plurality of lenses are adjusted while tilting the pair of guide shafts with respect to the front barrel. After that, fix the rear barrel to the middle barrel and set the zoom lens to the telephoto end. In a state in which the optical axis of the plurality of lenses is shifted relative to the intermediate lens barrel in a direction substantially orthogonal to the optical axis, and a pair of guide shafts are tilted with respect to the rear lens barrel. After the adjustment, the front lens barrel is fixed to the intermediate lens barrel.
[0018]
As described above, in the adjusting method of the imaging lens device according to the present invention, with the zoom lens positioned at the wide end, the rear barrel with respect to the intermediate barrel in a direction substantially orthogonal to the optical axis. By displacing relatively, it is possible to adjust the shift and inclination of the optical axis of the focusing lens with respect to the lens fixed to the intermediate lens barrel while tilting the pair of guide shafts with respect to the front lens barrel. With the zoom lens positioned at the telephoto end, the front barrel is relatively shifted with respect to the intermediate barrel in a direction substantially perpendicular to the optical axis, so that a pair of the rear barrels is provided. While tilting the guide shaft, adjust the deviation and tilt of the optical axis of the lens fixed to the front barrel with respect to the zoom lens, and fix the lens fixed to the front barrel with respect to the lens fixed to the intermediate barrel. In addition, it is possible to adjust the displacement and inclination of the optical axis of the zoom lens. Thus, it is possible to prevent the imaging performance from deteriorating over the entire zoom range between the telephoto end and the wide end.
[0019]
In addition, the imaging apparatus according to the present invention includes a plurality of lenses that form an image of a subject, the plurality of lenses arranged with their optical axes aligned, and a front lens barrel at least in the front-back direction of the optical axis. A lens barrel body divided into an intermediate lens barrel and a rear lens barrel, both ends of which are supported by the front lens barrel and the rear lens barrel, and a zoom lens among the lenses housed in the lens barrel body. A pair of guide shafts that movably support a focusing lens and an optical axis direction, and a solid-state imaging device that is attached to the rear barrel and captures an image of a subject formed by a plurality of lenses. The partial barrel and the rear barrel can be relatively displaced in a direction substantially orthogonal to the optical axis with respect to the intermediate barrel fixed while supporting both ends of the pair of guide shafts. It is characterized by having.
[0020]
As described above, in the imaging apparatus according to the present invention, one of the front lens barrel and the rear lens barrel that support both ends of the pair of guide shafts is substantially the same as the optical axis with respect to the intermediate lens barrel. A conventional lens is obtained by rotating the zoom lens and the focus lens together with the pair of guide shafts while relatively displacing the pair of guide shafts with respect to the other lens barrel while being relatively displaced in the orthogonal direction. The optical axes of a plurality of lenses can be adjusted without providing an adjustment mechanism or the like for adjusting the eccentricity or inclination of the lens, and the image of the subject formed by the plurality of lenses is appropriately captured on a solid-state imaging device. be able to.
[0021]
Further, in the adjusting method of the imaging apparatus according to the present invention, the plurality of lenses for forming an image of the subject and the plurality of lenses are arranged in a state where their optical axes are coincident with each other, and at least frontward in the front-rear direction of the optical axis. A lens barrel body divided into a main lens barrel, an intermediate lens barrel, and a rear lens barrel, and both ends supported by a front lens barrel and a rear lens barrel. A pair of guide shafts that support the lens and the focusing lens so as to be movable in the optical axis direction, and a solid-state imaging device that is attached to the rear barrel and captures an image of a subject formed by a plurality of lenses. When adjusting the optical axis of the imaging apparatus provided with the zoom lens positioned at the wide end, the rear barrel is relatively shifted with respect to the intermediate barrel in a direction substantially orthogonal to the optical axis, and While tilting a pair of guide shafts with respect to the After adjusting the optical axis of the body image sensor, the rear lens barrel is fixed to the intermediate lens barrel, and the front lens barrel is substantially illuminated with respect to the intermediate lens barrel with the zoom lens positioned at the telephoto end. After relatively adjusting the optical axes of the plurality of lenses with respect to the solid-state image sensor while tilting the pair of guide shafts with respect to the rear lens barrel, the front lens barrel is changed to the intermediate lens barrel. It is characterized by being fixed.
[0022]
As described above, in the adjusting method of the imaging apparatus according to the present invention, the rear lens barrel is positioned relative to the intermediate lens barrel in a direction substantially orthogonal to the optical axis with the zoom lens positioned at the wide end. By shifting the optical axis of the focusing lens with respect to the lens fixed to the intermediate lens barrel, it is possible to adjust the inclination and the tilt of the optical axis of the focusing lens with respect to the lens fixed to the intermediate lens barrel. With the zoom lens positioned at the telephoto end, the front barrel is relatively shifted with respect to the intermediate barrel in a direction substantially perpendicular to the optical axis, so that a pair of the rear barrels is provided. While tilting the guide shaft, adjust the deviation and tilt of the optical axis of the lens fixed to the front barrel with respect to the zoom lens, and fix the lens fixed to the front barrel with respect to the lens fixed to the intermediate barrel. In addition, it is possible to adjust the displacement and inclination of the optical axis of the zoom lens. As a result, it is possible to prevent the imaging performance from deteriorating over the entire zoom range between the telephoto end and the wide end, and to appropriately form an image of the subject on the light receiving surface of the solid-state imaging device.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an imaging lens device and an adjustment method thereof, and an imaging device and an adjustment method thereof according to the present invention will be described in detail with reference to the drawings.
[0024]
As shown in FIG. 1, an imaging apparatus 1 to which the present invention is applied includes a zooming lens housed in a lens barrel main body 2 among a plurality of lenses arranged with the optical axis aligned with the lens barrel main body 2. An image formed by the plurality of lenses is formed on an imaging lens device that performs zooming (magnification changing operation) and focusing (focus adjustment operation) by displacing the lens and the focusing lens in the optical axis direction. By mounting a solid-state image pickup device for picking up an image of the above, the entire device is made into a small package. Such an imaging device 1 is used as a device suitable for configuring a video camera, a digital still camera, or the like due to its miniaturization.
[0025]
The lens barrel main body 2 is made of a black resin material having strength and mass productivity and having a light-shielding property, for example, a polycarbonate resin containing glass fiber, and the front lens barrel 3 and the intermediate lens barrel 4 in the front-back direction of the optical axis. And a rear lens barrel 5.
[0026]
The front lens barrel 3 is positioned and fixed on the front side of the intermediate lens barrel 4, and has a plurality of positioning projections positioned with respect to the intermediate lens barrel 4 on its rear side, and a screw on the intermediate lens barrel 4. A plurality of through holes through which the screw to be stopped is formed are formed. On the other hand, a positioning hole into which the plurality of positioning protrusions are fitted and a plurality of screw holes into which screws passing through the plurality of through holes are screwed are formed on the front side of the intermediate lens barrel 4. I have. Therefore, the front lens barrel 3 is positioned with respect to the intermediate lens barrel 4 by engaging the positioning protrusions with the positioning holes of the intermediate lens barrel 4, and is also inserted into the screw holes of the intermediate lens barrel 4 through the through holes. The screw is fixed to the front side of the intermediate lens barrel 4 by screwing.
[0027]
The rear lens barrel 5 is positioned and fixed on the rear side of the intermediate lens barrel 4, and has a plurality of positioning projections positioned relative to the intermediate lens barrel 4 on the front side thereof. And a plurality of through holes through which screws are screwed are formed. On the other hand, a positioning hole into which the plurality of positioning protrusions are fitted and a plurality of screw holes into which screws passing through the plurality of through holes are screwed are formed on the back side of the intermediate lens barrel 4. I have. Therefore, the rear lens barrel 5 is positioned with respect to the intermediate lens barrel 4 by engaging the positioning projections with the positioning holes of the intermediate lens barrel 4, and is screwed into the screw holes of the intermediate lens barrel 4 through the through holes. Are fixed to the rear side of the intermediate lens barrel 4 by screwing.
[0028]
As shown in FIG. 2, the plurality of lenses include, from the subject side, a fixed lens group 9 including a first lens 6, a second lens 7, and a third lens 8 fixed to the front lens barrel 3, A movable zoom lens group 13 including a fourth lens 10, a fifth lens 11, and a sixth lens 12, which is driven to be displaced in the optical axis direction inside the intermediate barrel 4, and is fixed to the intermediate barrel 4. A movable lens for focusing comprising a seventh lens (fixed lens) 14 and an eighth lens 15, a ninth lens 16 and a tenth lens 17 which are displaced and driven in the optical axis direction inside the intermediate lens barrel 4. It has a lens group 18 and is configured as a so-called four-group inner focus type zoom lens.
[0029]
The fixed lens group 9 is mounted on a substantially cylindrical lens mounting portion 19 provided on the front surface of the front lens barrel 3. The fixed lens 14 is attached to a substantially annular lens attachment frame 20 provided on the inner peripheral portion of the intermediate lens barrel 4.
[0030]
On the other hand, the zoom movable lens group 13 and the focus movable lens group 18 are movably supported in the optical axis direction by a lens support mechanism. The lens support mechanism includes a zoom lens support member 21 that supports the zoom movable lens group 13, a focus lens support member 22 that supports the focus movable lens group 18, and a zoom lens and a focus lens. And a pair of guide shafts 23a and 23b that support the lens support members 21 and 22 in such a manner as to be slidable in the optical axis direction.
[0031]
The lens support members 21 and 22 for zoom and focus are made of a black resin material or the like having strength and mass productivity and having a light shielding property, and the lens support frames 21a holding the outer peripheral portions of the movable lens groups 13 and 18, respectively. , 22a.
[0032]
Further, the zoom lens support member 21 has a cylindrical portion 24 having a guide hole 24a through which one of the guide shafts 23a and 23b is inserted, and a guide that sandwiches the other guide shaft 23b. A support piece 25 having a groove 25a is formed, and the tubular portion 24 and the support piece 25 are formed so as to protrude from positions facing each other on the outer peripheral portion of the lens support frame 21a. The zoom lens support member 21 is configured such that one guide shaft 23a is inserted into the guide hole 24a of the cylindrical portion 24, and the other guide shaft 23b is sandwiched in the guide groove 25a of the support piece 25. Between the group 9 and the fixed lens 14, it is slidably supported along a pair of guide shafts 23a and 23b.
[0033]
On the other hand, the focusing lens support member 22 has a cylindrical portion 26 formed with a guide hole 26a through which one of the guide shafts 23a and 23b is inserted, and a guide that sandwiches the other guide shaft 23a. A support piece 27 having a groove 27a is formed, and the cylindrical portion 26 and the support piece 27 are formed to protrude from positions facing each other on the outer peripheral portion of the lens support frame 22a. The focusing lens support member 22 is described later by inserting the other guide shaft 23b into the guide hole 26a of the cylindrical portion 26 and inserting the one guide shaft 23a into the guide groove 27a of the support piece 27. Between the diaphragm 31 and the solid-state imaging device 35, the lens is slidably supported along a pair of guide shafts 23a and 23b.
[0034]
The pair of guide shafts 23a and 23b are arranged inside the intermediate lens barrel 4 in parallel with the optical axis, and both ends are fixedly supported between the front lens barrel 3 and the rear lens barrel 5. . For this reason, the front lens barrel 3 is formed with a pair of receiving portions 28a and 28b that fix and support one ends of the pair of guide shafts 23a and 23b. Further, the rear barrel 5 is formed with a pair of receiving portions 29a and 29b for fixedly supporting the other ends of the pair of guide shafts 23a and 23b. The pair of receiving portions 28a, 28b, 29a, 29b has a shape whose inner surfaces are flattened in all directions so as to hold the tips of the pair of guide shafts 23a, 23b to be lightly press-fitted. I have. A pair of through holes 30a, 30b through which a pair of guide shafts 23a, 23b penetrate is formed in the lens mounting frame 20 of the intermediate lens barrel 4.
[0035]
Further, the one guide shaft 23a and the other guide shaft 23b are arranged such that the lens support members 21 and 22 for zooming and focusing are arranged in a state of being inclined by approximately 45 ° with respect to the direction of gravity. The main body 2 is provided at corner portions facing each other. Further, the zoom lens support member 21 and the focus lens support member 22 are arranged with a phase difference of 180 ° with respect to the pair of guide shafts 23a and 23b. Thereby, it is possible to suppress the rattling of the zoom and focus lens support members 21 and 22 with respect to the pair of guide shafts 23a and 23b.
[0036]
The intermediate lens barrel 4 has a lens driving mechanism for displacing and driving the zoom lens support member 21 and the focus lens support member 22 in the optical axis direction along a pair of guide shafts 23a and 23b. Is provided. Although not shown, the lens driving mechanism independently drives the lens supporting members 21 and 22 supported by the pair of guide shafts 23a and 23b in the optical axis direction by driving a stepping motor, a linear motor, or the like. . The intermediate lens barrel 4 is provided with a reset sensor and the like for initializing the lens driving mechanism when power is turned on.
[0037]
A stop 31 is arranged in the intermediate lens barrel 4 between the fixed lens 14 and the movable lens group 18 for focusing. The diaphragm 31 is formed integrally with an iris unit 32 positioned and fixed to the intermediate lens barrel 4, and the iris unit 32 slides two shutter members (not shown) by driving a drive motor 33. The aperture 31a of the diaphragm 31 is adjusted while adjusting.
[0038]
In the rear lens barrel 5, an optical filter 34 and a solid-state image sensor 35 are arranged on the image plane side of a subject formed by a plurality of lenses. For this reason, the solid-state imaging device 35 is fitted to the substantially central portion on the rear side of the rear barrel 5 via the first fitting concave portion 36 into which the optical filter 34 is fitted and the rectangular frame-shaped sealing rubber 37. The second fitting recess 38 to be formed is continuously formed in a step shape. A rectangular opening 39 corresponding to the opening 37 a of the seal rubber 37 is formed on the bottom surface of the first fitting recess 36.
[0039]
The seal rubber 37 is fitted to the solid-state imaging device 35 and has an opening 37a formed with a predetermined size in order to prevent unnecessary light from entering the solid-state imaging device 35.
[0040]
The optical filter 34 includes an infrared cut filter 34a for preventing near-infrared light from reaching the solid-state imaging device 35, and a low-pass cut filter 34b for extracting a specific spatial frequency component from light traveling to the solid-state imaging device 35. Are bonded together.
[0041]
The solid-state imaging device 35 photoelectrically converts incident light and outputs the electric signal as an electric signal. A semiconductor chip 35a such as a charge-coupled device (CCD) or a complementary mental-oxide semiconductor device (CMOS) is mounted on the wiring substrate 40. Has a structure mounted on the A plurality of connection terminals 41 for projecting an electric signal output from the semiconductor chip 35a to an external signal processing circuit or the like are provided protrudingly on the rear surface side of the wiring board 40. The solid-state imaging device 35 is attached to a sheet metal 42 and positioned and fixed on the rear side of the rear barrel 5. For this reason, a pair of positioning holes for positioning the solid-state imaging device 35 in the rear barrel 5 and a pair of through holes through which screws screwed to the rear barrel 5 are formed are formed in the sheet metal 42. I have. On the other hand, on the rear side of the rear barrel 5, a pair of positioning projections engaged with the pair of positioning holes and a pair of screw holes into which screws passing through the pair of through holes are screwed are formed. I have.
[0042]
Then, when attaching the optical filter 34 and the solid-state imaging device 35 to the rear barrel 5, first, the optical filter 34 is fitted into the first fitting concave portion 36. Next, the solid-state imaging device 35 is fitted into the second fitting recess 38 via the seal rubber 37 fitted to the semiconductor chip 35a. At this time, the seal rubber 37 presses the optical filter 34 with a predetermined elastic force by being pressed against the optical filter 34 fitted in the first fitting recess 36. This prevents rattling of the optical filter 34 fitted in the first fitting concave portion 36 and also prevents rattling of the solid-state imaging device 35 fitted in the second fitting concave portion 38. be able to. Next, the sheet metal 42 to which the solid-state imaging device 35 is attached is fixed to the rear side of the rear barrel 5. That is, the sheet metal 42 to which the solid-state imaging device 35 is attached is configured such that a pair of positioning protrusions is engaged with a pair of positioning holes, and a screw is screwed into a pair of screw holes through a pair of through holes. , Is positioned and fixed on the rear side of the rear barrel 5. Thereby, the optical filter 34 and the solid-state imaging device 35 can be positioned and fixed with high precision with respect to the rear barrel 5.
[0043]
In the imaging apparatus 1 configured as described above, while performing zooming (magnification changing operation) for displacing the movable lens group 13 for zooming in the optical axis direction, the image plane of the subject formed by the plurality of lenses and the solid Focusing (focus adjustment operation) of displacing the movable lens group 18 for focusing in the optical axis direction is performed so that the light receiving surface of the image sensor 35 coincides with the light receiving surface. Thus, the focal length can be continuously changed while keeping the image plane of the subject formed by the plurality of lenses and the light receiving surface of the solid-state imaging device 35 in agreement.
[0044]
For example, in the wide position shown in FIG. 3, the movable lens group 13 for zoom is positioned at the most front side (wide end), so that the image of the subject formed on the light receiving surface of the solid-state imaging device 35 has the widest angle ( Wide). On the other hand, in the tele-position shown in FIG. 4, by positioning the zoom movable lens group 13 at the rearmost side (tele end), the image of the subject formed on the light receiving surface of the solid-state imaging device 35 is most telephoto ( Tele).
[0045]
In the image pickup apparatus 1, the solid-state image sensor 35 receives the image of the object formed by the plurality of lenses, and processes the electric signal output from the solid-state image sensor 35 to correspond to the image of the object. Digital image data can be generated.
[0046]
By the way, in order to prevent the deterioration of the imaging performance of the lens and to reproduce the design performance at a high level, as described above, it is not possible to solve the problem only by improving the precision of the parts, and therefore, the deviation of the optical axis between the lenses. So-called alignment assembly, which is assembling while adjusting (eccentricity) and inclination, is effective.
[0047]
In the above-described imaging apparatus 1, there is play in the engagement between the positioning holes provided in the front barrel 3 and the rear barrel 5 and the positioning protrusions provided on the front and back surfaces of the intermediate barrel 4. Accordingly, one of the front lens barrel 3 and the rear lens barrel 5 that supports both ends of the pair of guide shafts 23a and 23b is moved relative to the intermediate lens barrel 4 in a direction substantially orthogonal to the optical axis. The movable lens groups 13 and 18 for zooming and focusing can be rotated together with the pair of guide shafts 23a and 23b while tilting the pair of guide shafts 23a and 23b with respect to the other lens barrel. is there.
[0048]
Thereby, the optical axis adjustment between the lenses and the optical axis adjustment of the plurality of lenses with respect to the solid-state imaging device 35 can be easily and appropriately performed without providing an adjustment mechanism for adjusting the eccentricity and inclination of the lens as in the related art. It is possible. In the imaging apparatus 1, the number of parts is reduced, and the structure is simplified, whereby the entire apparatus can be downsized. By reducing the number of assembling steps, the cost can be reduced. .
[0049]
Next, a method suitable for performing the above-described optical axis adjustment of the imaging device 1 will be described.
[0050]
In general, where a light beam is largely bent, the occurrence of aberrations that deteriorate the imaging performance of the lens increases. In paraxial optics, when the focal length is f, the surface power (refractive index) is Φ, the incident ray height is h, and the argument is Δu, the relationship Φ = 1 / f, Δu = Φ × h Holds, the higher the ray height, the stronger the effect of surface refraction.
[0051]
Here, at the wide position shown in FIG. 7 described above, the height of the light beam is high between the fixed lens 103 and the movable lens group 104 for zooming. This shows that the eccentricity and inclination of the optical axis between the fixed lens 103 and the movable lens group 104 for zoom greatly affect the imaging performance. On the other hand, at the telephoto position shown in FIG. 8 described above, the ray height is high between the fixed lens group 101 and the movable lens group 102 for zooming, and the distance between the fixed lens 103 and the movable lens group 104 for zooming is high. But the ray height is high. From this, the eccentricity and inclination of the optical axis between the fixed lens group 101 and the zoom movable lens group 102 greatly affect the imaging performance, and the fixed lens 103 and the zoom movable lens group 104 It can be seen that the eccentricity and inclination of the optical axis between them greatly affect the imaging performance.
[0052]
Therefore, in the entire zoom range between the telephoto end and the wide end, the eccentricity and inclination of the optical axis between the fixed lens 103 and the zoom movable lens group 104 greatly affect the imaging performance.
[0053]
Therefore, when performing the above-described optical axis adjustment of the imaging apparatus 1, first, with respect to the intermediate lens barrel 4 in the wide position shown in FIG. 3, that is, with the zoom movable lens group 13 located at the wide end. By displacing the rear barrel 5 relatively in a direction substantially perpendicular to the optical axis, the pair of guide shafts 23a and 23b are tilted with respect to the front barrel 3 while the rear barrel 5 is tilted to the lens mounting frame 20 of the intermediate barrel 4. The shift and the inclination of the optical axis of the focus movable lens group 18 with respect to the fixed lens 14 are adjusted.
[0054]
At this time, since the fixed lens group 9 does not move the front lens barrel 3 with respect to the intermediate lens barrel 4, it remains at the original position. Although the movable lens group 13 for zooming is rotated together with the pair of guide shafts 23a and 23b, it is located on the frontmost side, close to the front barrel 3, and with respect to the front barrel 3. Since there is little effect of tilting the pair of guide shafts 23a, 23b, the guide shafts 23a and 23b are slightly shifted in the direction orthogonal to the optical axis with respect to the original position and slightly tilted with respect to the optical axis. Since the fixed lens 14 is fixed to the lens mounting frame 20 of the intermediate lens barrel 4, it remains at the original position. The diaphragm 31 remains at the original position because the iris unit 32 is fixed to the intermediate lens barrel 4. The movable lens group 18 for focusing is shifted together with the pair of guide shafts 23a and 23b in a direction perpendicular to the optical axis with respect to the original position and tilts with respect to the optical axis.
[0055]
As a result, it is possible to prevent the imaging performance from deteriorating over the entire zoom range between the telephoto end and the wide end. In this state, the rear barrel 5 is screwed or adhered to the intermediate barrel 4. Fix it.
[0056]
Here, in the teleposition shown in FIG. 4, as described above, the eccentricity or inclination of the optical axis between the fixed lens group 9 and the movable lens group 13 for zooming may greatly affect the imaging performance. Conceivable. In addition, in the above-described wide position shown in FIG. 3, it is concluded that the movable lens group 13 for zooming is slightly shifted with respect to the original position in the direction orthogonal to the optical axis and slightly tilted with respect to the optical axis. It is also conceivable that this may affect image performance.
[0057]
In the tele position shown in FIG. 4, that is, with the movable lens group 13 for zoom positioned at the tele end, the front barrel 3 is moved relative to the intermediate barrel 4 in a direction substantially orthogonal to the optical axis. The fixed lens group 9 fixed to the lens mounting portion 19 of the front lens barrel 3 with respect to the zoom movable lens group 13 while tilting the pair of guide shafts 23a and 23b with respect to the rear lens barrel 5 The fixed lens group 9 fixed to the lens mounting portion 19 of the front lens barrel 3 with respect to the fixed lens 14 fixed to the lens mounting frame 20 of the intermediate lens barrel 4 and the zoom lens are adjusted. Of the optical axis of the movable lens group 13 is adjusted.
[0058]
Thus, it is possible to prevent the imaging performance from deteriorating at the telephoto position. In this state, the front lens barrel 3 is fixed to the intermediate lens barrel 4 by screwing, bonding, or the like.
[0059]
In the imaging apparatus 1 in which the optical axis has been adjusted as described above, it is possible to guarantee sufficient imaging performance of the lens over the entire zoom range between the telephoto end and the wide-angle end. The image of the formed subject can be appropriately captured by the solid-state imaging device 35.
[0060]
Therefore, in this imaging apparatus 1, even if the lens is downsized and the pixels of the solid-state imaging device 35 are made finer in order to improve the image quality and resolution of a still image or the like, the zoom between the telephoto end and the wide end is reduced. Sufficient optical performance can be guaranteed over the entire area, and the overall size of the device can be reduced in order to improve portability and ease of use.
[0061]
Further, in the imaging device 1, the configuration of the iris unit 32 is not limited to the above, and for example, as in an iris unit 43 shown in FIG. 5, a pair of insertion holes 44a and 44b inserted through a pair of guide shafts 23a and 23b. And the diaphragm 31 may be fixedly supported by the pair of guide shafts 23a and 23b.
[0062]
In this case, since the stop 31 is rotated together with the pair of guide shafts 23a and 23b when the above-described optical axis adjustment is performed, the eccentricity and inclination of the stop 31 with respect to a plurality of lenses after the alignment is assembled. Can be prevented, and it is possible to prevent inclination (shading) or the like from occurring in the brightness on the image plane when the aperture 31a of the aperture 31 is narrowed.
[0063]
Note that the present invention is not limited to the imaging device 1 configured as the above-described four-group inner-focus zoom lens, but includes a mirror among a plurality of lenses arranged with the optical axis aligned with the lens barrel main body. An imaging lens device that forms an image of a subject by displacing a part of the lenses housed in the cylinder body in the optical axis direction, and a solid image of the subject formed by such an imaging lens device. The present invention can be widely applied to an imaging device that performs imaging by an imaging device.
[0064]
In addition, the present invention is not limited to the above-described configuration as a shift adjusting unit that shifts the front barrel 3 and the rear barrel 5 in the direction substantially orthogonal to the optical axis with respect to the intermediate barrel 4, It is also possible to shift the front lens barrel 3 and the rear lens barrel 5 in a direction substantially orthogonal to the optical axis with respect to the intermediate lens barrel 4 by applying an external force, and to perform shift adjustment using a jig or a pin. Is also possible.
[0065]
That is, according to the present invention, of the front barrel and the rear barrel that support both ends of the pair of guide shafts, one of the barrels is relatively positioned with respect to the intermediate barrel in a direction substantially orthogonal to the optical axis. Shift and tilt the pair of guide shafts with respect to the other barrel, and rotate the lens supported by the pair of guide shafts together with the pair of guide shafts to adjust the eccentricity and tilt of the lens as in the past This makes it possible to easily and appropriately adjust the optical axis of the lens without providing an adjusting mechanism or the like for performing the adjustment.
[0066]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to easily and appropriately adjust the optical axes of a plurality of lenses without providing an adjustment mechanism or the like for adjusting the eccentricity or inclination of the lens as in the related art. By reducing the number of parts and simplifying the structure, it is possible to reduce the size of the entire apparatus, and it is possible to reduce the cost by reducing the number of assembly steps.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an appearance of an imaging apparatus to which the present invention is applied.
FIG. 2 is a cross-sectional view illustrating an internal structure of the imaging device.
FIG. 3 is a cross-sectional view showing a state in which the image pickup device has the widest angle.
FIG. 4 is a cross-sectional view showing the most telephoto state in the imaging apparatus.
FIG. 5 is a cross-sectional view illustrating a modification of the imaging device.
FIG. 6 is a configuration diagram showing a conventional imaging device.
FIG. 7 is a configuration diagram showing a state in which the conventional image pickup apparatus has the widest angle of view.
FIG. 8 is a configuration diagram showing a state in which the telephoto is maximized in the conventional imaging apparatus.
[Explanation of symbols]
1 imaging device, 2 lens barrel main body, 3 front lens barrel, 4 intermediate lens barrel, 5 rear lens barrel, 9 fixed lens group, 13 movable lens group for zoom, 14 fixed lens, 18 movable lens group for focus, 23a, 23b A pair of guide shafts, 31 stop, 32 iris unit, 34 optical filter, 35 solid-state image sensor, 43 iris unit

Claims (4)

A plurality of lenses for forming an image of the subject,
A plurality of lenses are arranged with their optical axes aligned with each other, and a lens barrel body divided into a front lens barrel, an intermediate lens barrel, and a rear lens barrel at least in the front-back direction of the optical axis,
Both ends are supported by the front barrel and the rear barrel, and among the lenses housed in the barrel main body, a zoom lens and a focus lens are movably supported in the optical axis direction. With a pair of guide shafts,
The front barrel and the rear barrel are relatively displaced in a direction substantially orthogonal to the optical axis with respect to the intermediate barrel fixed while supporting both ends of the pair of guide shafts. An imaging lens device, characterized in that: A plurality of lenses for forming an image of a subject, and the plurality of lenses are arranged with their optical axes aligned, and at least in the front-rear direction of the optical axis, a front barrel, an intermediate barrel, and a rear barrel. The lens barrel body is divided into two, and both ends are supported by the front lens barrel and the rear lens barrel. Among the lenses housed in the lens barrel body, a zoom lens and a focus lens are used. When performing an optical axis adjustment of an imaging lens device including a pair of guide shafts that are movably supported in the optical axis direction,
With the zoom lens positioned at the wide end, the rear barrel is relatively displaced relative to the intermediate barrel in a direction substantially orthogonal to the optical axis, and the pair of lenses is positioned relative to the front barrel. After adjusting the optical axes of the plurality of lenses while tilting the guide shaft, the rear barrel is fixed to the intermediate barrel,
With the zoom lens positioned at the telephoto end, the front barrel is relatively shifted with respect to the intermediate barrel in a direction substantially orthogonal to the optical axis, and the pair of the front barrels is positioned relative to the rear barrel. Adjusting the optical axes of the plurality of lenses while tilting the guide shafts, and then fixing the front lens barrel to the intermediate lens barrel. A plurality of lenses for forming an image of the subject,
A plurality of lenses are arranged with their optical axes aligned with each other, and a lens barrel body divided into a front lens barrel, an intermediate lens barrel, and a rear lens barrel at least in the front-back direction of the optical axis,
Both ends are supported by the front barrel and the rear barrel, and among the lenses housed in the barrel main body, a zoom lens and a focus lens are movably supported in the optical axis direction. A pair of guide shafts,
A solid-state image sensor that is attached to the rear barrel and captures an image of a subject formed by the plurality of lenses;
The front barrel and the rear barrel are relatively displaced in a direction substantially orthogonal to the optical axis with respect to the intermediate barrel fixed while supporting both ends of the pair of guide shafts. An imaging apparatus, characterized in that: A plurality of lenses for forming an image of a subject, and the plurality of lenses are arranged with their optical axes aligned, and at least in the front-rear direction of the optical axis, a front barrel, an intermediate barrel, and a rear barrel. The lens barrel body is divided into two, and both ends are supported by the front lens barrel and the rear lens barrel. Among the lenses housed in the lens barrel body, a zoom lens and a focus lens are used. Optical axis adjustment of an image pickup apparatus including a pair of guide shafts movably supported in the optical axis direction and a solid-state image pickup device attached to the rear barrel and imaging an image of a subject formed by the plurality of lenses. When doing
With the zoom lens positioned at the wide end, the rear barrel is relatively displaced relative to the intermediate barrel in a direction substantially orthogonal to the optical axis, and the pair of lenses is positioned relative to the front barrel. After adjusting the optical axes of the plurality of lenses while tilting the guide shaft, the rear barrel is fixed to the intermediate barrel,
With the zoom lens positioned at the telephoto end, the front barrel is relatively shifted with respect to the intermediate barrel in a direction substantially orthogonal to the optical axis, and the pair of the front barrels is positioned relative to the rear barrel. And adjusting the optical axes of the plurality of lenses while tilting the guide shafts. Then, fixing the front lens barrel to the intermediate lens barrel.

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