JPH01108513A - Position adjusting and holding device for lens - Google Patents

Abstract

PURPOSE:To improve the workability at the time of fine adjustment of a lens position and the stability of the position precision by setting the width of a groove and the thickness of a lens bracket so that a lead groove can be engaged to the end face of a notch of a bent-up piece. CONSTITUTION:The width of a groove and the thickness of a lens bracket 2 are set so that a lead groove 8 can be engaged to the end face of a notch K of at least one bent-up piece of two pieces of bent-up pieces 2A, 2B which have been bent to such a cross sectional shape as one side of a regular square has lacked. Also, other bent-up parts 2C, 2D of the lens bracket 2 are fixed with screws 6 to the left and the right side plates 3, 4 for constituting the body. In such a way, the lens position is set with high accuracy and with satisfactory workability, and also, an inexpensive position adjusting and holding device for a lens is obtained.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a lens position adjustment and holding device, and more particularly to a lens position adjustment and holding device that can be applied to optical systems such as image reading scanners and copying machines. It is.

(prior art).

The following techniques are known as means for holding the lens outer barrel and adjusting the lens outer barrel in the optical axis direction.

(1) Technique of (1) receiving the lens outer cylinder surface with a block and fixing the lens to the V block using a semicircular holding band (Japanese Utility Model Publication No. 13604/1983).

(2) The combination of the block and the semicircular holding band is shown in (1) above.
), but ■Technology to perform fine adjustment by inserting and removing a spacer between the lens contact surface of the block and the rear end surface of the lens (
(Japanese Patent Application Laid-Open No. 58-174909).

(3) ■Technology in which a long hole is provided at the bottom of the groove, a screw is inserted, and it is directly fixed with the female screw of the lens barrel
Publication No. 10).

(4) Tighten the outer cylinder with grooves on the outer circumferential surface to the block through an intermediate member such as felt. Then, when the tightening is loosened and the outer cylinder is rotated, the groove and the felt act as a screw, making it possible to make slight movements of the lens.
Publication No. 4).

(5) A technique in which a rectangular hole smaller than the diameter of the lens outer cylinder and longer than the length of the outer cylinder is made in a thin metal plate, and the lens is pressed and clamped with a support band (Japanese Utility Model Publication No. 16885/1985).

However, these techniques have problems in workability and stability when finely adjusting the lens position.

(Objective) Therefore, an object of the present invention is to provide a lens positioning and holding device that can improve workability during fine adjustment of lens position and improve stability of positional accuracy.

(Structure) In order to achieve the above object, the present invention includes a lead group formed on the lens outer cylinder, and a lens bracket made of a thin plate having a section bent into a cross-sectional shape like a square with one side cut off. , is held in contact with a substantially ■-shaped notch formed in each of the bent pieces along the optical axis direction perpendicular to the facing surface of each of the bent pieces of this lens bracket, and an inclined end surface of each of the above-mentioned notches. It has a clamp member that presses and holds the lens outer cylinder portion against the lens bracket, and is configured such that the lead group can engage with an end surface of the notch of at least one of the two bent pieces. The lens bracket is characterized by setting the group width and the thickness of the lens bracket.

Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

In FIG. 1, the reference numeral 2 indicates a lens bracket, and the bent piece 2 is bent into a cross-sectional shape similar to that of a square with one side missing.
A, 2B (see Figure 2).

The other bent portions 2C and 2D of the lens bracket 2 are fixed to the left and right side plates 3 and 4 of the main body by screws 6.

The direction perpendicular to the facing surfaces of the bent pieces 2A and 2B corresponds to the direction penetrating the plane of paper in FIG. 1 and the left-right direction in FIG. 2, and is the same direction as the optical axis 0 of the lens 1.

The bent pieces 2A and 2B each have an angle θ= along the optical axis 0.
A 7-shaped notch K of 90" is formed. The opposing inclined end surfaces constituting this notch are designated by symbols 10A and I, respectively.
Indicated by IA, IOB, and IIB (see Fig. 1 and Fig. 6) - The lens outer cylinder part IA holding the lens 1 is placed in the above-mentioned 7-shaped notch, and in detail, the above-mentioned four inclined end surfaces 10
A, IIA, 108.118 are in contact with the lens outer cylinder portion IA.

On top of that, the lens outer cylinder part IA is attached to the clamp member 5 from above.
The clamp member 5 is pressed and held by tightening the clamp member 5 to the lens bracket with a screw 7.

In FIG. 2, which shows a cross section taken along the line A-A in FIG.
A lead group 8 is formed over two areas.

This lead group 8 is a spiral groove, and although the shape of the groove is trapezoidal in this example, it is not limited to this and may be any shape.

However, the lead is the adjustment range of lens 1 (required travel distance)
Determined by. As a general value, L is set to about 1 to 4 mm.

This lead group 8 engages with the inclined end surfaces 10A and IIA of the two bent pieces as shown in FIG.

Therefore, the lens outer cylinder portion IA has each V of the bent pieces 2A and 2B.
It is held by the letter-shaped notch. When adjusting the lens position, loosen the clamp member 5, grasp the lens outer cylinder part IA, and rotate it to adjust the position in the optical axis O direction due to the threaded relationship between the lead group 8 and the inclined end faces 10A and IIA. is slightly moved.

In this way, for example, the lens 1 can be moved to the optimal position while observing the image projected by the lens 1.

However, in this type of adjustment work, it is usually difficult to find the optimum position, and it is often the case that the operator realizes that he has passed the optimum position after passing the optimum position. Then, when it realizes that it has passed the optimal position, it repeats the same process by changing the direction of rotation to the opposite direction.

In other words, the optimum position is reached by gradually reducing the difference while repeating back and forth with trial ## error.

After that, tighten the screw 7 and the work is completed.

In this case, before and after tightening the screw 7,
The shaped notch has a great effect of stably holding the lens outer cylinder part 1.

This will be explained in more detail.

In FIG. 1, the points of contact between the inclined end surfaces 10A and IIA of the bent piece 2A, which is the front bent portion of the lens bracket 2, and the lens outer cylinder portion IA are indicated by cylinder numbers to and tt.

If the opening angle connecting the contact point 10.11 and the optical axis 0 of the lens I is 01, then this angle 01 is 906. That is, the angle is the same as the angle θ of the notch. The angle 0=01 may be arbitrary, but it is generally set to 90°.

As is clear from FIG. 3, which illustrates the engagement state between the bent piece 2A and the lead group 8, the two bent pieces are attached to the lead group nib 8.
It is in contact with the bottom part 9 of.

In the figure, the solid line represents the lead group 8 at the contact 10 that engages with the inclined end surface 10A, and the contact 1 that engages with the inclined end surface 11A.
Lead group 8 in the construction is shown with a dashed line.

When the leads of lead group 8 are indicated by L, a lead difference Q occurs between contacts 10 and 11 in the optical axis 0 direction.

This lead difference Q is given by the following equation from the relationship between the opening angle 0 and the lead L.

Therefore, if L = 3 mm and 0 = 90'', then the width of the bottom portion 9 of the lead group 8 is W, and the bent piece 2A is
If the plate thickness of is T, then the following equation is set as a condition for the bending piece 2A to be in contact with the bottom part 9.

15w-n...(2) Furthermore, T<W
- Backlash occurs under -Q. In that case, backlash B is B=(W-4)-T...(
3).

If the movement directions of the lens outer cylinder portion 1 are the same, the existence of the backlash B will not be a problem, but the lens l
When adjusting the pin or magnification, which requires constant back-and-forth rotation in order to correct excessive or excessive movement during adjustment, if the backlash is large, the continuity of the response will be interrupted. Adversely affects workability.

Therefore, for example, as shown in Figure 4, if we consider the plate thickness T under the condition that no backlash occurs, T=W-111 (4), the plate thickness T is determined by the standard. Freedom of choice is restricted. For example, in the case of a cold rolled mild steel plate according to JIS (1,0+nm≦T≦2mm), the range is 1.0.
There are only 1.2.1.6.2.0 thicknesses.

Therefore, it is necessary to select W or Q appropriately.

In this case, it is effective to apply equation (5), which is obtained by transforming equation (4) using equation (1).

That is, it is possible to match the predetermined plate thickness T by selecting the width W, the lead L, or the angle 0.

Next, an example in which the plate thickness can be made larger than the above example will be explained with reference to FIG.

In this case, in order to reduce backlash, the bent piece 2
The positions of the inclined end surfaces 10A and IIA on the human body are not on the same plane, but are slightly shifted in the direction of the optical axis 0 (see FIG. 6).

If this shift amount is Q', it is set so that n'=u. According to the previous example, Q'' = Q = 0.75 mm.In addition, in the example of Fig. 5, both the inclined end faces 10A and IIA contact the bottom corner of the lead group 8 at four points, two points each. becomes.

Next, an example in which the width W of the bottom portion 9 of the lead group 8 is small will be described.

In the case of this example, as shown in FIG. 7, the tip of the bent piece 2A does not reach the bottom 9, but comes into contact with it at a slope in the middle. This is because the lead group 8 has a trapezoidal shape, and by doing so, backlash can be eliminated.

Incidentally, if the groove width of the lead group 8 at the portion where the bent piece 2A is in contact is W', then the case shown in FIG. 7.

T=W'-Q (6).

This relationship is the same as equation (4).

In the embodiment described above, the combination of the lens bracket 2 and the lead group 8 is made by pressing a thin plate, so unlike screws, there is no need for threading with a mating thread, and the precision is not as strict, resulting in a lens that is inexpensive and easy to work with. A position adjustment and holding device can be obtained.

Further, by appropriately selecting the groove width of the lead group 8 based on the plate thickness and the lead difference, it is possible to perform adjustment with less backlash.

Further, by adjusting the dimensions of the bending process by the lead difference between the lead groups, it is possible to perform adjustment with less backlash.

(Effects) According to the present invention, it is possible to provide an inexpensive lens position adjustment and holding device that can determine the lens position with high precision and good workability, and is therefore advantageous.

[Brief explanation of the drawing]

FIG. 1 is a front view of the lens position adjustment and holding device according to the present invention, FIG. 2 is a sectional view taken along the line A-A in the same figure, and FIGS. FIG. 6, which is a diagram explaining the relationship with the bending mortar, is a top view of the lens bracket. IA... Lens outer barrel, 2... Lens bracket, 5... Clamp member, 8... Lead group, 10A, IIA, IOB, IIB...
・Slope end face, K...notch.

Claims (1)

[Claims] Means for holding a lens outer cylinder part and moving and adjusting the lens outer cylinder part in the optical axis direction, the lead group formed in the lens outer cylinder part and one side of a square being cut out. A lens bracket made of a thin plate having a bent portion in a cross-sectional shape as shown in FIG. V
a clamp member that presses and holds the lens outer cylinder portion held in contact with the inclined end surface of each of the notches to the lens bracket, and at least one of the two bent pieces is bent. A lens position adjustment and holding device characterized in that the groove width and the thickness of the lens bracket are set so that the lead groove can engage with the end face of the notch of the piece.