JPS62133407A - Fixing device for lens barrel - Google Patents

Abstract

PURPOSE:To form finely an image of an original on a photodetecting part even if the accuracy of the size of a fixing member is dispersed by providing a part pressed against the top part of a lens barrel out of a lens barrel fixing member pressed against the top part of a lens and locked with a lens barrel supporting member at its leg part with spring property. CONSTITUTION:A lens barrel press 10 fixing the lens barrel 2 on the opposite edge of a groove hole 4 on a supporting plate 7 is pressed against the lens barrel at its top part. The fixing press 10 consists of a plate material such as metal or synthetic resin and the part 10' pressed against the top part of the lens barrel 2 has especially elastic (spring property) structure. About the press 10 in its free state, the part 10' pressed against the top part of the lens barrel 2 is projected to the side pressed against the lens barrel 2 like an M- shape as a whole and especially provided with spring property in the direction pressed against the lens barrel so as to be easily distorted by delta at the press contact with the lens barrel. Consequently, the lens barrel 2 is excited by the whole surface of the width of the lens press 10 in the optical axis direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a device for fixing a lens barrel holding a lens that forms an image of a document on a light receiving section.

(Prior Art and its Problems) Conventionally, this type of device uses a solid-state image sensor such as a CCD as a light receiving section, as shown in FIG. 4(a).

In Figure 0, which is configured as shown in (b), l is a solid-state image sensor, 2 is a lens barrel containing a lens that forms an image of the original onto the solid-state image sensor l, 3 is an optical axis, and 4
is a lens barrel guide slot that plays the role of a guide for supporting the lens barrel 2 and adjusting its movement in the optical axis direction;
The support plate 7 is bored. 5 is a lens barrel holder made of a sheet metal for fixing the lens barrel; 6 is a screw for fixing the lens barrel 2 to the lens holder 5; here.

In the case of the configuration shown in Figure 4, lens barrel 2 and lens tat: 4
If the processing precision of the presser foot 5 is good and the stopper 6 of the lens presser foot 5 is closed, if the entire surface of the lens barrel presser 5 falls evenly on the lens barrel 2 in the optical axis direction, the lens barrel presser 5 Before and after closing the stopper door 6, there is no possibility that the best imaging plane will not be formed on the solid-state image sensor due to the misalignment of the reading 1 [11 position. However, in general, the lens barrel 2 and the lens barrel holder 5 are For example, Fig. 1 (a), (b)
), the end to which force F is applied and the other end are θ1, as shown in Figure 4(C) and (d).
Only 02 stands out. Therefore, the optical axis of the lens does not match before and after closing the stopper 6 of the lens barrel holder 5, so that the image formed on the solid-state image sensor l is
Although it was fine before tightening the stop screw 6, it becomes misaligned after tightening the stop screw 6.

(Objective) An object of the present invention is to provide a lens barrel fixing device that solves the drawbacks of the prior art and prevents the best image formation on the light receiving section from shifting before and after fixing the lens barrel. .

(Summary of the Invention) In the present invention, at least the portion of the lens barrel fixing member that presses against the top of the lens and has one leg secured to the lens barrel support member has spring properties. are doing.

(Embodiment) FIGS. 1(a), (b), and (c) are explanatory diagrams of an embodiment of the present invention, in which the same members as in FIG. 4 are given the same numbers,
48, the explanation will be omitted unless necessary.

A lens barrel holder 10, which fixes the lens barrel 2 to the opposite edge of the slot 4 of the support plate 7, is pressed against the lens barrel at the top of the lens barrel 2, as shown in FIG. This fixing presser lO is a plate material such as metal 1 and synthetic resin that has spring properties.
It has a structure rich in:

That is, when the presser foot 10 is in a free state (that is, in an unloaded state with the support plate 7 removed), as shown in FIG. It has a convex shape and is M-shaped as a whole. Therefore, the portion 10' has particularly high springiness in the direction of pressure contact with the lens barrel, and easily bends by the amount δ when pressed against the lens barrel.

In the above configuration, the screw 6 is loosened and the lens barrel is slightly moved parallel to the optical axis so that the image on the fixed image sensor is near the best. Thereafter, the screw 6 is tightened and the lens barrel 2 is fixed with the lens holder 10. At that time, use the lens holder l.
O has a mechanism in which the lens barrel 2 is fixed by positively imparting spring properties to its upper portion 1σ. Therefore, even if the outer dimensions of the lens barrel 2 and the outer dimensions of the lens holder lO do not match each other very much, the pressure contact portion of the lens barrel top of the lens barrel holder 10 has a spring property, and by tightening the screw 6, the lens barrel holder lO
Since the whole 111 in the optical axis direction is brought into pressure contact with the lens barrel by elastically deforming, the force with which the lens presser lO presses the lens barrel in the optical axis direction is F and f, as shown in Fig. 1(e). Although it is a little different, since the lens barrel 2 is biased by the entire width of the lens holder 10 in the optical axis direction, the optical axis of the lens barrel does not tilt before and after closing the stop 6 of the lens holder 10, and a solid image is created. There is no deviation of the best image formation plane on the sensor.

In the examples shown in FIGS. 3(a), (b), and (C), the lens barrel holder 11
This is an example in which a slit-shaped cutout 11' is provided in the pressure contact portion of the top of the lens barrel, thereby enhancing the springiness of the pressure contact portion of the top of the lens barrel. In this example, the presser foot 11 is free! Although the island may have a substantially U-shape as shown in FIG. 3(b), it is more preferable to have an M-shape as shown in FIG. There are some advantages that you can get.

Note that another photoreceptor such as an electrophotographic photoreceptor may be disposed in the light receiving section.

(Effects) As explained above, according to the present invention, even if the dimensional accuracy of the fixing member varies, the lens optical axis can be positioned with almost no movement before and after the lens barrel is fixed, so that the original image can be received. The image can be formed well in the area.

[Brief explanation of drawings]

FIG. 1(a) is a plan view of an embodiment of the present invention, and FIG. 1(b) is a plan view of an embodiment of the present invention.
) is a front view of the same embodiment, FIG. 1(C) is a side view of the same embodiment, FIG. 2 is an explanatory diagram of the lens barrel holder as a fixing member, and
Figure (a) is a plan view of another embodiment of the present invention, Figure 3 (b)
3(c) is a side view of the same embodiment, FIG. 4(a) is a side view of the conventional example, FIG. 4(b) is a front view of the conventional example, FIG. 4(C) and FIG. 4(d) are explanatory diagrams of the disadvantages of the conventional example. 2 is a lens barrel, 4 is a slot, 7 is a support plate, and 10.11 is a lens holder.

Claims (2)

[Claims] (1) In a device for fixing a lens barrel holding a lens that forms an image of an original on a light receiving section, a lens barrel support member having a groove into which the lens barrel is inserted and supported, and a lens barrel support member having a groove for supporting the lens barrel, and A fixing member that fixes the lens barrel to the support member by being in pressure contact with the lens barrel support member and having its legs locked with the lens barrel support member (at least the portion of this fixing member that is in pressure contact with the top of the lens barrel has a spring property). ) and a lens barrel fixing device. (2) The lens barrel fixing device according to claim 1, wherein the fixing member has an M-shape in a free state.