JPH0943474A - Fastening structure for lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new fastening structure for a lens barrel capable of absorbing a force applied at an assembling time and at dropping without making a lens barrel large in size and weight. SOLUTION: As for the fastening structure for the lens barrel provided with a housing 2 formed of a front housing 3 and a back housing 4, a positioning fitting part 17a(17b) constituted of a positioning projection 8a(8b) projecting from the front housing 3 and a positioning fitting hole 16a(16b) formed in the back housing 4 and to which the projection 8a(8b) is accurately fitted, at least one auxiliary fitting part 19 is formed, the part 19 is constituted of an auxiliary projection 9 projecting from the front housing 3 and an auxiliary fitting hole 18 formed on the back housing 4 and to which the auxiliary projection 9 is fitted, and a gap between the auxiliary projection 9 and the auxiliary fitting hole 18 is made larger than a gap between the positioning projection 8a(8b) and the positioning fitting hole 16a(16b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel lens barrel fastening structure. Specifically, it is intended to provide a novel lens barrel fastening structure capable of absorbing a force applied during assembly or dropping.

[0002]

2. Description of the Related Art FIGS. 6 to 13 show an example of a conventional lens barrel fastening structure.

The housing b of the lens barrel a is formed by combining a front housing c and a rear housing d.

A positioning protrusion e is provided from the rear end of the front housing c.
1, e2 are provided in a protruding manner, and screw holes f1, f2, f3 opened on the rear surface are formed.

Positioning fitting holes g1 and g2 which are open to the front are formed in the rear housing d. Positioning fitting hole g1
Is formed in a circular shape having a diameter with which the positioning projection e1 is fitted almost exactly, and the positioning fitting hole g2 is formed as a long hole in the direction of arrangement with the positioning fitting hole g1 and the width of which is equal to that of the positioning projection e2. It is formed to have almost the same size as the outer diameter.

A flange h protruding outward is formed at the front end of the rear housing d, and the flange h is screwed in positionally with the screw holes f1, f2, f3 of the front housing c. The insertion holes i1, i2, i3 are formed.

In order to connect the front housing c and the rear housing d, first, the positioning protrusions e1 and e2 of the front housing c are fitted into the positioning fitting holes g1 and g2 of the rear housing d. Then, both are accurately positioned. That is, the positioning protrusion e1 is fitted in the positioning fitting hole g1 to perform accurate positioning in this portion, and the positioning protrusion e2 is fitted in the positioning fitting hole g2, so that the positioning protrusion e1 is positioned. The position in the rotation direction around the fitting portion between the positioning fitting hole g1 and the positioning fitting hole g1 is regulated, and thereby both c and d are accurately positioned.

As described above, with the front case c and the rear case d positioned, the screws j, j, j are inserted through the screw insertion holes i1, i2, i3 of the rear case d to move the front case. It is screwed into the screw holes f1, f2, f3 of the partial housing c, and by this,
The front housing c and the rear housing d are joined together to form a housing b.

[0009]

By the way, in the above-described lens barrel fastening structure, the front housing c and the rear housing d are provided.
There is a problem that the rear housing d is deformed when the screws are tightened.

In the assembly process, the screw tightening is usually performed using an electric torque driver in consideration of the efficiency of the work.

Since the electric torque driver has a large torque, when the screws j, j, j are tightened, the torque is applied to the flange h of the rear housing d, for example, as shown in FIG.
As shown in FIG. 11, the rear housing d is deformed in the range of the shape difference between the screw insertion hole i and the screw j (the state shown by the broken line in FIG. 11 is a normal state. In FIG. 11, the degree of deformation is exaggerated. Is shown). Then, such deformation extends to the actuator mounting portion k ((a) is in a normal state and (b) is in a deformed state) as shown in FIG. The rear housing d is attached to the rear housing d at an angle, which causes various problems such as hindering the movement of the movable lens moved by the actuator l and deviating its position accuracy. In addition, due to the deformation of the rear housing d, the position of the support hole m of the guide shaft formed in the rear housing d is displaced, and the guide shaft is no longer parallel to the optical axis. There is a problem of causing.

In recent years, as the magnification of the lens has been increased, the processing accuracy and the assembly accuracy required for parts of the lens barrel have become stricter. On the other hand, in consideration of downsizing and weight reduction of products, the thickness of the constituent parts is thinner. And a shape with low rigidity tends to be selected. As a result, if the rigidity of the component becomes low, deformation such as the above-mentioned deformation at the time of screw tightening, deformation of the component in the process of applying a load to the component such as soldering, etc. easily occurs, and the component is damaged at the time of drop impact. It will be easier to do.

Therefore, if the rigidity of each part is increased in order to secure the processing accuracy and the assembly accuracy, the product becomes large,
There is a problem that the product becomes heavy and the product quality is impaired.

In view of such circumstances, the present invention provides a novel lens barrel fastening structure capable of absorbing the force applied at the time of assembly or dropping without causing an increase in size and weight. The challenge is to provide.

[0015]

In order to solve the above-mentioned problems, the lens barrel fastening structure of the present invention has at least two partial casings, each of which has a casing formed therein. In a lens barrel fastening structure having at least two positioning fitting portions, each of which includes a positioning projection formed on the other part of the housing and a positioning fitting hole formed on the other partial housing for accurately fitting the positioning projection, An auxiliary fitting portion is formed at one place, and the auxiliary fitting portion includes an auxiliary projection formed on one partial housing and an auxiliary fitting hole formed on the other partial housing into which the auxiliary projection is fitted. The gap between the auxiliary protrusion and the auxiliary fitting hole is larger than the gap between the positioning protrusion and the positioning fitting hole.

Therefore, in the lens barrel fastening structure of the present invention, even if one of the partial casings is deformed at the time of screw tightening or drop impact, the auxiliary fitting portion acts to prevent such deformation. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the fastening structure for a lens barrel of the present invention will be described below with reference to the illustrated embodiments.

The housing 2 of the lens barrel 1 is formed by combining a front housing 3 and a rear housing 4, which are partial housings. Then, various fixed lenses, movable lenses (not shown)
The lens barrel 1 is formed by supporting or attaching necessary elements such as an actuator for a movable lens and an iris.

A first group lens (fixed lens) 6 is supported at the center of the front end wall 5 of the front housing 3. Further, screw lower holes 7a and 7b are formed at both left and right ends of the upper end of the rear end, and screw lower holes 7c are formed at substantially the center of the lower end. Further, positioning protrusions 8a and 8b are provided at substantially the center of the left and right ends of the rear end in the vertical direction. Furthermore, an auxiliary projection 9 is provided right next to the lower screw hole 7c.

Further, guide shaft support holes 10a and 10b are formed at diagonal positions of the front end wall 5, and the guide shaft support holes 10a and 10b are arranged in the front housing 3 in parallel with the optical axis direction. A front end portion of a guide shaft (not shown) arranged is supported.

The tips of the protrusions 8a, 8b, 9 are tapered in a tapered shape. Also, each protrusion 8
The protruding lengths of a, 8b and 9 are longer than 9 in 8a and 8b.

A CC is provided in the center of the rear end wall 11 of the rear housing 4.
Imaging unit 12 having a solid-state imaging device such as a D image sensor
Is supported, and a flange portion 13 projecting outward is integrally formed at the front end portion.

Guide shaft support holes 14a and 14b are formed at diagonal positions of the rear end wall 11, and the guide shaft support holes 1 are formed.
A rear end portion of a guide shaft (not shown) arranged in parallel with the optical axis in the rear housing 4 is supported by the rear housings 4a and 14b.

Screw insertion holes 15a, 15b, 15c are formed in the left and right ends of the upper side of the flange 13 and in the center of the lower side.
Are formed. In addition, positioning fitting holes 16a and 16b are formed in the central portions of the left and right sides of the flange portion 13. The positioning fitting hole 16a is formed in a circular shape having a diameter into which the positioning projection 8a is fitted with a clearance on the order of microns, and the positioning fitting hole 16b is arranged in the direction of arrangement with the positioning fitting hole 16a, that is, In the case of this example, it is formed in a long hole that is long in the left-right direction, and the size in the width direction is set to a size in which the positioning projection 8b is fitted with a clearance on the order of microns. The positioning projections 8a and the positioning fitting holes 16a and the positioning projections 8b and the positioning fitting holes 16b form positioning fitting portions 17a and 17b.

An auxiliary fitting hole 18 is formed adjacent to the screw insertion hole 15c on the lower side. The auxiliary fitting hole 18 is formed in a circular shape having a diameter into which the auxiliary projection 9 is fitted almost exactly, and the clearance between the auxiliary fitting hole 18 and the auxiliary projection 9 is between the positioning projection 8a and the positioning fitting hole 16a. And the clearance between the positioning protrusion 8b and the width direction of the positioning fitting hole 16b are formed to be slightly larger. Then, the auxiliary protrusion 9 and the auxiliary fitting hole 18 form an auxiliary fitting portion 19.

However, in order to connect the two partial housings 3 and 4, first, the projections 8a, 8b and 9 and the fitting holes 16a, 16b and 18 in the fitting portions 17a, 17b and 19 are fitted. To combine. At this time, the positioning protrusion 8 with a large protrusion amount
The a and 8b first start to fit into the positioning fitting holes 16a and 16b, and then the auxiliary protrusion 9 starts to fit into the auxiliary fitting hole 18.

Then, the positioning projection 8a and the positioning fitting hole 16a are fitted together to perform positioning at this portion, and the positioning projection 8b and the positioning fitting hole 16b are fitted together to form the positioning fitting portion 17a. Positioning in the direction of rotation around the center is performed. And in this way, 2
When the three partial housings 3 and 4 are positioned with respect to each other, the screw lower holes 7a, 7b, 7c of the front housing 3 and the screw insertion holes 15a, 15b, 15c of the rear housing 4 are aligned with each other. The mounting screws 20, 20, 20 are screw insertion holes 15a, 15b,
15c is inserted and screwed into the screw holes 7a, 7b, 7c, whereby the front housing 3 and the rear housing 4 are integrally coupled to form the housing 2.

When the mounting screws 20, 20, 20 are tightened, for example, when the tightening is performed by an electric torque driver, the torque is passed through the head of the mounting screw 20 and the flange portion 13 of the rear housing 4. For example, a force is applied leftward toward the front at the portion of the screw insertion hole 15c far from the positioning fitting portions 17a and 17b, whereby the portion of the screw insertion hole 15c of the rear housing 4 is moved forward toward the left. Although the force to shift in the direction is received, the force is received by the front housing 3 due to the fitting in the auxiliary fitting portion 19, and the rear portion having a clearance equal to or larger than the clearance between the auxiliary protrusion 9 and the auxiliary fitting hole 18 is received. The deformation of the housing 4 is prevented.

Further, even if the front housing 3 and / or the rear housing 4 tries to be deformed due to the impact of the lens barrel 1 being dropped, other auxiliary fitting other than fitting in the positioning fitting portions 17a, 17b is performed. The fitting by the joint portion 19 also prevents such deformation. In addition, the positioning protrusions 8a, 8
The shearing force applied to b is also dispersed by the auxiliary protrusion 9 of the auxiliary fitting portion 19, and the positioning protrusions 8a and 8b are less likely to break.

In the lens barrel 1, the projections of the positioning projections 8a and 8b are larger than that of the auxiliary projection 9, but this is the same as the projections of all the projections 8a, 8b and 9. You can do the same. However, as described above, the protrusion amount of the positioning protrusions 8a and 8b is set to the auxiliary protrusion 9
If it is made larger than that, the front housing 3 and the rear housing 4
At the time of coupling with, the positioning protrusions 8a and 8b are first inserted into the positioning fitting holes 16a and 16b and serve as guides, so that the auxiliary protrusion 9 is easily fitted into the auxiliary fitting hole 18. The same effect can be obtained by reversing this protrusion amount and making the protrusion amount of the auxiliary protrusion 9 larger than that of the positioning protrusions 8a and 8b.

Although the auxiliary fitting portion is formed at one place in the lens barrel 1, two or more auxiliary fitting portions may be provided.

[0032]

As is apparent from the above description, in the lens barrel fastening structure of the present invention, a housing is formed by at least two or more partial housings, and one of the partial housings is coupled to each other. At least one of the lens barrel fastening structures is provided with a positioning fitting portion formed at two locations, the positioning fitting portion including the formed positioning projection and the positioning fitting hole formed in the other partial housing for accurately fitting the positioning projection. Auxiliary fitting portions are formed at a plurality of locations, and the auxiliary fitting portions include an auxiliary projection formed on one partial housing and an auxiliary fitting hole formed on the other partial housing into which the auxiliary projection is fitted. The gap between the auxiliary protrusion and the auxiliary fitting hole is larger than the gap between the positioning protrusion and the positioning fitting hole.

Therefore, in the lens barrel fastening structure of the present invention, the auxiliary fitting portion acts to prevent such deformation even if one of the partial casings is deformed at the time of screw tightening or drop impact. .

Therefore, the assembling can be performed without unnecessarily increasing the rigidity of each of the partial casings constituting the casing, that is, without increasing the size and weight of the partial casing. It is possible to prevent deformation of the partial housing due to the load when tightening screws or soldering, and the auxiliary projections function as stoppers when the drop impact occurs, improving impact resistance performance and preventing deformation and damage of parts. it can.

[Brief description of drawings]

1 shows an embodiment of a fastening structure for a lens barrel of the present invention, together with FIGS. 2 to 5, and is a partially cutaway side view of the lens barrel.

FIG. 2 is a partially cutaway side view of a front housing.

FIG. 3 is a schematic rear view of a front housing.

FIG. 4 is a partially cutaway side view of a rear housing.

FIG. 5 is a schematic front view of a rear housing.

FIG. 6 shows an example of a conventional lens barrel fastening structure together with FIGS. 7 to 13, and is a partially cutaway side view of the lens barrel.

FIG. 7 is a partially cutaway side view of the front housing.

FIG. 8 is a schematic rear view of the front housing.

FIG. 9 is a partially cutaway side view of the rear housing.

FIG. 10 is a schematic front view of a rear housing.

FIG. 11 is a schematic front view of a rear housing showing a problem.

FIG. 12 illustrates another problem with FIG.
This figure is a schematic cross-sectional view of the rear housing, in which (a) shows a normal state and (b) shows a deformed state.

FIG. 13 is a schematic bottom view of a rear housing.

[Explanation of symbols]

 1 Lens barrel 2 Housing 3 Front housing (partial housing) 4 Rear housing (partial housing) 8a, 8b Positioning protrusion 9 Auxiliary protrusion 16a, 16b Positioning fitting hole 17a, 17b Positioning fitting part 18 Auxiliary Mating hole 19 Auxiliary mating part

Claims (4)

[Claims] 1. A casing is formed by at least two partial casings, and a positioning protrusion formed on one of the partial casings and a positioning protrusion formed on the other partial casing are fitted with precision. In a fastening structure of a lens barrel in which a positioning fitting portion including a matching positioning fitting hole is formed at two locations, at least one auxiliary fitting portion is formed, and the auxiliary fitting portion is one partial casing. And an auxiliary fitting hole formed in the other partial housing and into which the above-mentioned auxiliary projection is fitted. The gap between the auxiliary projection and the auxiliary fitting hole is the positioning projection and the positioning fitting. A fastening structure for a lens barrel, characterized in that the gap is larger than the gap between the holes. 2. The lens barrel fastening structure according to claim 1, wherein the partial housings are fastened together by screws, and the auxiliary fitting portion is provided near the screw fastening portion. 3. The lens barrel fastening structure according to claim 1, wherein the positioning protrusion and the auxiliary protrusion have different protrusion lengths. 4. The lens barrel fastening structure according to claim 2, wherein the positioning protrusion and the auxiliary protrusion have different protrusion lengths.