JP2000184262A - Back focus adjustment mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the deviation between an optical axis and the center of an image pickup element due to assembling and back focus adjustment of a camera and to prevent the tilt of the image pickup element with respect to the optical axis. SOLUTION: The back focus adjustment mechanism turns a focus adjustment ring 32 to move an image pickup element 60 mounted on a board 62 in forward backward directions. At least, two guide pins 64 are placed upright from a reference member in parallel with the moving direction of the image pickup element 60 and the guide pins 64 are penetrated through an image pickup element mount board 62 and an element seat 58 provided between the board 62 and the image pickup element 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back focus adjusting mechanism for a camera, for example, a surveillance camera. The present invention relates to a back focus adjustment mechanism for adjusting.

[0002]

2. Description of the Related Art In a conventional back focus adjusting mechanism, as shown in FIG. 4, a focus adjusting ring 10 and a substrate mounting portion 12 are in contact with each other via a leg member 14 mounted on the ring 10. 10, the substrate mounting portion 12 moves along the guide screw 16 with the arrow L
It is configured to move in the front-back direction indicated by. 18
Denotes a lens, 20 denotes a lens mounting base (front), 22 denotes a coil spring (spring), 24 denotes an image sensor, and 26 denotes an image sensor mounting board.

[0003]

In a conventional back focus adjusting mechanism as shown in FIG.
When attaching the imaging element mounting substrate 26 to the second boss 28, the image sensor mounting substrate 26 is screwed into the round hole of the substrate 26 with a screw 30. At this time, the optical axis is aligned with the center of the imaging element 24 while watching the image on the monitor. adjust. At this time, there is a problem that variation occurs due to the skill of the worker. Also,
The diameter b of the ring 10 is the lens mounting base (front) 2
Since the height a is lower (smaller) than 0, there is a problem that it is difficult to adjust the lens 18 when the diameter of the lens 18 is large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to adjust the back focus of a camera and to minimize the deviation between the center of the image sensor and the optical axis due to assembly. It is to provide a mechanism. Another object of the present invention is to provide a back focus adjustment mechanism capable of preventing the image sensor from falling with respect to the optical axis. A further object of the present invention is to provide a back focus adjustment mechanism that can easily perform back focus adjustment even when a lens having a large diameter such as a zoom lens is attached.

[0005]

In order to achieve the above object, a back focus adjusting mechanism of the present invention moves an image pickup device mounted on a substrate in a front-rear direction by rotating a focus adjusting ring. A back focus adjusting mechanism as described above, wherein at least two guide pins are provided so as to stand from a reference member in parallel with a moving direction of the image sensor, and these guide pins pass through the image sensor mounting substrate. Is configured. Further, the back focus adjustment mechanism of the present invention is a back focus adjustment mechanism configured to move an image pickup device arranged on an element pedestal provided with a positioning mechanism in a front-rear direction by rotating a focus adjustment ring. At least two guide pins are provided so as to stand from the reference member in parallel with the moving direction of the imaging element, and these guide pins penetrate the element pedestal. Further, the back focus adjustment mechanism of the present invention is a back focus adjustment mechanism configured to move an image pickup device mounted on a substrate in the front-rear direction by rotating a focus adjustment ring, wherein the movement direction of the image pickup device is It is provided that at least two guide pins stand from the reference member in parallel to the base member, and that these guide pins penetrate the imaging element mounting substrate and the element pedestal provided between the substrate and the imaging element. (See FIGS. 1 and 2). In these back focus adjustment mechanisms, it is preferable to use a lens mounting pedestal (front) as a reference member (see FIGS. 1 and 2).

A back focus adjusting mechanism according to the present invention further comprises a focus adjusting ring having a female screw portion on an inner periphery;
A cylindrical portion having an external thread on which the female thread of the focus adjusting ring is screwed on the outer surface, a female screw on which the male screw of the lens is screwed on the inner surface, and a flange integrally provided on the periphery of the cylindrical portion. A lens mounting pedestal provided, a ring-shaped carrier provided between the focus adjustment ring and the lens mounting pedestal and having an opening into which the cylindrical portion of the lens mounting pedestal is inserted, and integrated with the ring-shaped carrier in the front-rear direction. At least two through the hole of the lens mounting pedestal
A book carrier pin, a coil spring provided around the carrier pin to absorb back-and-forth backlash between the ring-shaped carrier and the lens mounting pedestal, an element pedestal to which the imaging element is attached, An element circuit board fixed substantially parallel to the element pedestal, and at least two guide pins mounted in the front-rear direction on the lens mounting pedestal, the element pedestal is screwed to a carrier pin,
The guide pin is characterized in that it penetrates the hole of the element pedestal and the hole of the element circuit board (see FIGS. 1 and 2).

In these back focus adjusting mechanisms, it is preferable that the diameter of the focus adjusting ring is formed so as to be larger than the height of the lens mounting base (see FIG. 3). With this configuration, the back focus can be easily adjusted even when the zoom lens is attached.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications. is there. FIG. 1 is a longitudinal sectional configuration diagram of a back focus adjustment mechanism according to a first embodiment of the present invention,
FIG. 2 is an exploded perspective view. Reference numeral 32 denotes a focus adjustment ring having a knurled portion 34 on the outer periphery and a female screw portion 3 on the inner periphery.
6. 38 is a lens mounting base (front)
A cylindrical portion 40 and a flange portion (flange portion) 42 provided integrally with a peripheral edge of the cylindrical portion 40 are provided. The cylindrical part 40 has a male screw part 44 on the outer surface, and a female screw part 46 with which the male screw part of the lens is screwed on the inner surface.

Reference numeral 48 denotes a ring-shaped carrier having an opening 49 into which the cylindrical portion 40 is inserted. The front-back direction of this ring-shaped carrier 48 (the direction of arrow L in FIGS. 1 and 2)
2 or more (two in FIG. 1 and FIG. 2 as an example)
Carrier pins 50 are provided. The carrier pin 50 passes through a hole 52 provided in the flange 42 of the lens mounting base 38. A coil spring (spring) 54 is disposed around the carrier pin 50 between the carrier ring 48 and the flange 42 of the lens mounting base 38. At the front of the hole 52, a grooved coil spring receiver 56 is provided.
Is provided.

Reference numeral 58 denotes an element base on which an image pickup element 60 is mounted. The element circuit board 62 is arranged in parallel with the element base 58.
Is attached. That is, the element circuit board 62 serves as an imaging element mounting board. The element circuit board 62 is mounted on the element base 58.
The method of mounting in parallel, for example, adopts a method of sandwiching a spacer of uniform thickness between the element pedestal and the element circuit board, forming a spacer by bending the element pedestal, or erecting a boss Is done. However, strictly, it is not necessary to ensure that the element pedestal and the element circuit board are kept parallel. What needs to be kept parallel is the imaging element and the element pedestal (since the element pedestal and the reference member are kept parallel). The substrate may be configured to be substantially parallel as long as the effect of the guide pin functions reliably. Lens mounting base 3
Two or more (two as an example in FIGS. 1 and 2) guide pins 64 are attached to the front and rear direction 8. The guide pin 64 may be provided by being screwed into the flange 42 of the lens mounting base 38 as shown in FIG. 2, or may be formed integrally with the flange 42.

The element pedestal 58 has a screw 6
6 screwed. The guide pin 64 is assembled so as to pass through the hole 68 of the element pedestal 58 and the hole 70 of the element circuit board 62. The shape of the flange 42 of the lens mounting base, the shape of the element base 58, the element circuit board 62
The shape such as is not limited to the illustrated shape, and can be appropriately modified.

In the back focus adjusting mechanism constructed as described above, each member shown in FIG.
To the state shown in. Then, the male screw portion 74 of the lens 72
Is screwed into the female screw portion 46 of the cylindrical portion 40 of the lens mounting base 38, and the lens 72 is mounted. As described above, the guide pins 64 are provided on the rear surface of the lens mounting pedestal 38, and the guide pins 64 are passed through the element circuit board 62 on which the
The zero center and the optical axis can be easily and precisely adjusted. In order to prevent the image sensor 60 from falling down with respect to the optical axis, an element pedestal 58 is sandwiched between the image sensor 60 and the element circuit board 62. Are screwed to the carrier pin 50 passing through the hole 52. The guide pin 64 also passes through the hole 68 of the element pedestal 58.

By rotating (rotating) the focus adjusting ring 32 in the forward and reverse directions, the ring-shaped carrier 48 and the carrier pin 50 move in the front-back direction. At that time, since the element circuit board 62 moves in the front-back direction along the two guide pins 64, the back focus can be adjusted. In FIGS. 1 and 2, the positioning of the imaging element is performed by the substrate, but a method of incorporating the function into the element pedestal is also possible. For example, it is not necessary to penetrate the substrate by providing a positioning mechanism for the imaging element on the element pedestal.

FIG. 3 is a side view of a back focus adjusting mechanism according to a second embodiment of the present invention. In the present embodiment, the diameter B of the focus adjustment ring 32a is configured to be larger than the height A of the lens mounting base (front) 38a. By doing so, the back focus can be easily adjusted even when various lenses, for example, large lenses such as zoom lenses are attached. Other configurations and operations are the same as those in the first embodiment.

[0015]

As described above, the present invention has the following effects. (1) Easy to assemble the back focus adjustment mechanism,
In addition, fine adjustments can be made. Further, conventionally, the deviation between the center of the image sensor and the optical axis has been corrected at the factory while watching the image, but the trouble can be saved. (2) The adjustment by the operator can be omitted, and the variation can be suppressed. (3) The number of parts is small, the assembling is easy, and the center deviation, the inclination, and the backlash in the circumferential direction of the image sensor with respect to the optical axis can be suppressed. (4) When the diameter of the focus adjustment ring is made larger than the height of the lens mounting base (front), the back focus can be easily adjusted even when a large lens such as a zoom lens is mounted.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional configuration diagram of a back focus adjustment mechanism according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the back focus adjustment mechanism shown in FIG.

FIG. 3 is a side view of a back focus adjustment mechanism according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional configuration diagram showing an example of a conventional back focus adjustment mechanism.

[Explanation of symbols]

 32 Focus Adjustment Ring 34 Knurl 36, 46 Female Thread 38 Lens Mounting Base (Front) 40 Cylindrical 42 Flange (Flange) 44, 74 Male Thread 48 Ring Carrier 49 Opening 50 Carrier Pin 52, 68, 70 Hole 54 Coil spring 56 Coil spring receiver 58 Element pedestal 60 Image sensor 62 Element circuit board 64 Guide pin 66 Screw 72 Lens

Claims (6)

[Claims] 1. A back focus adjusting mechanism for moving an image pickup device mounted on a substrate in a front-rear direction by rotating a focus adjustment ring, wherein a back focus adjustment mechanism is provided in parallel with a moving direction of the image pickup device from a reference member. At least 2
A back focus adjusting mechanism, wherein the guide pins are provided so as to stand up, and these guide pins penetrate through the imaging element mounting substrate. 2. A back focus adjusting mechanism for moving an image pickup device disposed on an element pedestal provided with a positioning mechanism in a front-rear direction by rotating a focus adjustment ring, wherein the moving direction of the image pickup device is At least 2 from the reference member parallel to
A back focus adjusting mechanism, wherein the guide pins are provided so as to stand, and these guide pins penetrate the element pedestal. 3. A back focus adjusting mechanism for moving an image pickup device mounted on a substrate in a front-rear direction by rotating a focus adjustment ring, wherein the back focus adjustment mechanism comprises a reference member parallel to a moving direction of the image pickup device. At least 2
A back focus adjustment mechanism, wherein the guide pins are provided so as to stand, and these guide pins penetrate an image sensor mounting substrate and an element pedestal provided between the substrate and the image sensor. 4. The back focus adjusting mechanism according to claim 1, wherein the reference member is a lens mounting base. 5. A focus adjustment ring having an internal thread on the inner periphery, a cylindrical portion having an external thread on which an external thread of the focus adjustment ring is screwed and an internal thread on which an external thread of the lens is screwed on the inner surface. A lens mounting base provided with a flange integrally provided on the periphery of the cylindrical part; and an opening provided between the focus adjustment ring and the lens mounting base, into which the cylindrical part of the lens mounting base is inserted. A ring-shaped carrier having at least two carrier pins provided integrally with the ring-shaped carrier in the front-rear direction and penetrating through a hole of the lens mounting pedestal; A coil spring provided around the carrier pin to absorb backlash in the direction, an element pedestal on which the image sensor is mounted, and fixed substantially parallel to this element pedestal An element circuit board, and at least two guide pins attached to the lens mounting pedestal in the front-rear direction. The element pedestal is screwed to the carrier pin. A back focus adjustment mechanism characterized by passing through a hole in a substrate. 6. The back focus adjusting mechanism according to claim 4, wherein a diameter of the focus adjusting ring is formed to be larger than a height of the lens mounting base.