JPH0522891Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a focus adjustment mechanism that adjusts the distance between the image sensor and the lens of a camera.

(Prior art) Conventionally, a lens holder containing a built-in lens is screwed to a camera case housing a solid-state image sensor through a cylindrical adapter, and the screwed joint between the camera case and the adapter is slid in the axial direction. There was a camera focus adjustment mechanism that adjusted the distance between the image sensor and the lens and fixed it at the in-focus position by adjusting and fixing it with a set screw.

(Problem that the invention aims to solve) However, when fixing the threaded joint part with a set screw at the focal point position, the tip of the set screw bites into the threaded joint part, causing deformation, distortion, damage, etc. to the screw thread. However, once the screw thread is damaged, traces of the damage remain, making it difficult to make subsequent smooth adjustments or precise fine adjustments.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional art, and aims to provide a mechanism that can adjust and fix the focal point without causing damage to the threaded joint.

(Means for Solving the Problems) Hereinafter, the configuration of this invention will be explained in detail based on the embodiments shown in the drawings.

FIG. 1 is a partially cutaway sectional view of a main part of a focus adjustment mechanism of a camera.

In FIG. 1, a lens holder 4 housing a lens 3 is screwed coaxially through a cylindrical adapter 5 to the front surface of a camera case 2 in which a solid-state image sensor 1 is built on a printed circuit board 11.

In this state, the image sensor 1 and the lens 3 are arranged coaxially and facing each other. Adapter 5 and camera case 2
The screw connection part between the image sensor 1 and the lens 3 can be slid in the axial direction, and when the distance between the image sensor 1 and the lens 3 is adjusted to the in-focus position, the set screw 6 can be adjusted.
It is designed to fix the screw connection part.

As shown in FIG. 2, the adapter 5 has threads (grooves) formed on the inner and outer walls, and the threads are removed at approximately the middle position of the outer peripheral wall to form a circumferential groove 7. .

The width of the circumferential groove 7 is selected to be larger than the range in which the camera case 2 and the adapter 5 are screwed together in the axial direction, which is necessary for adjusting the focus position. And set screw 6
By pressing the tip of the groove into contact with the circumferential groove 7,
It is fixed to the camera case 2 at the focal point position.

As shown in FIG. 1, the camera case 2 is formed with a cylindrical portion 8 that protrudes from the front side of the image sensor 1.
The outer circumferential wall threaded portion 9 of the adapter 5 is coupled to the inner circumferential wall threaded portion of the cylindrical portion 8, and the inner circumferential wall threaded portion 1 of the adapter 5
A threaded portion of the outer circumferential wall of the lens holder 4 is coupled to the lens holder 0 .

The threaded portions 9 and 10 of the adapter 5 may be formed only on one peripheral wall so that both the camera case 2 and the lens holder 4 are screwed together there. Further, a threaded portion is formed on the outer peripheral wall of the cylindrical portion 8 of the camera case 2, and a circumferential groove is formed in this threaded portion, and the tip of the set screw screwed into this circumferential groove from the adapter 5 is pressed. It is also possible to make contact.

(Function) It is configured as described above, and in Fig. 1,
When the set screw 6 is slightly loosened, the adapter 5 becomes rotatable relative to the cylindrical portion 8 of the camera case 2. When the adapter 5 is rotated left and right, it moves forward and backward in the axial direction. By this sliding operation, the distance between the lens 3 and the image sensor 1 is adjusted, and when the focus is achieved, the set screw 6 is tightened and fixed. The focal position is determined by the width of the circumferential groove 7, and the movable range of the adapter 5 is similarly restricted, so the focus adjustment operation is as follows:
Simple, easily and quickly done.

At this time, since the tip of the set screw 6 is in pressure contact with the circumferential groove 7, the screw thread 9 is prevented from being deformed, distorted, or damaged. When replacing the lens holder or performing maintenance and inspection, readjustment and precise fine adjustment of the focal position can be easily and smoothly performed.

(Effect of the invention) As described above, according to this invention, the distance between the camera's image sensor and the lens can be easily and quickly adjusted to the in-focus position without damaging the screw connection part. A remarkable practical effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view of a main part of a focus adjustment mechanism of a camera embodying this invention, and FIG. 2 is a perspective view of the same adapter. 1...Image sensor, 2...Camera case, 3...
Lens, 4... Lens holder, 5... Adapter,
6... Set screw, 7... Circumferential concave groove.

Claims (1)

[Scope of utility model registration request] A lens holder with a built-in lens is screwed to a camera case with a built-in image pickup element through a cylindrical adapter, and the screwed connection part between the camera case and the adapter is adjusted by sliding in the axial direction, and the locking screw is set at the in-focus position. In the focus adjustment mechanism of the camera, the screw thread of the screw connection part is cut into a band shape to form a circumferential groove, and the tip of the set screw contacts the circumferential groove. A camera focus adjustment mechanism characterized by: