JP2554289Y2 - Focusing device for lens barrel for optical equipment - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is intended for a standard / wide-angle lens in which the extension amount of a lens barrel is 1 mm or less, such as a standard lens / wide-angle lens of a CCTV camera lens. The present invention relates to a focusing device for a lens barrel for an optical device.

[Prior Art] A mechanism for moving a lens barrel in the front-rear direction for focusing (hereinafter referred to as focusing) of an optical system in a lens barrel for an optical device is called a helicoid focus adjusting mechanism, and is a hollow lens. Parallel screw provided on cylindrical body (hereinafter referred to as helicoid screw)
Many mechanisms using are used. In particular, a hollow cylinder provided with a helicoid screw is referred to as a helicoid cylinder, the male screw side is referred to as an inner helicoid cylinder or a male helicoid cylinder, and the female screw side is referred to as an outer helicoid cylinder or a female helicoid cylinder. Generally, a female helicoid cylinder is fixed to an external operation member, and in addition to a helicoid screw composed of a multi-leaded screw having a large lead screwed with the male helicoid cylinder, a fixing on a member side to be mounted on the optical device main body. Where you screw it into your body,
The helicoid screw has a screw with a different screw direction and a small pitch. The male helicoid cylinder holds the optical system, and the fixed body is connected with the straight guide key and the key groove in relation to each other, and by rotating the female helicoid cylinder, the thrust of the helicoid screw turns the male helicoid cylinder into the key groove. It has a function to go straight along. This mechanism is called a straight-line helicoid focus adjustment mechanism, and is often used in lens barrels for optical instruments of intermediate grade or higher.

The helicoid cylinder of the lens barrel for optical equipment is required to have particularly high precision and good operability. Therefore, conventionally, in the case of a helicoid screw, as a means for securing the above-mentioned requirements, screwing is performed after machining such as whirling, and then lapping is performed. Processing was performed while checking the degree of rotation feeling of the
Processing costs were high.

However, recently, particularly in the lens barrel for optical equipment, it has become an essential condition to provide high-performance products to the market at extremely low prices. In the past, all components of the lens barrel for optical equipment were made of high-precision parts using metal materials, thereby forming a high-quality lens barrel. Plastic molding technology and metal manufacturing technology With the development of technologies such as these, plastic moldings are also actively adopted for lens barrels for optical equipment that require high performance, and processing costs, eventually product prices are reduced, product weight is reduced, etc. Product development responding to market demands is being made.

[Problems to be Solved by the Invention] However, using a plastic molded product for the helicoid cylinder of the lens barrel for optical equipment is cost-effective in order to obtain a higher quality product. However, it could not be provided as a part that sufficiently satisfies the purpose. Therefore, at present, it is incorporated in products of intermediate and lower grades. The first reason for this is the problem of molding distortion generated when molding a helicoid cylinder with a plastic material. Since helicoid screws are formed on the circumference of the cylindrical body, in order to eliminate the overhang of the screw part, it is necessary to remove the die or form at least a split mold with a three-part mold configuration In either case, it is very difficult to produce a molded part with a high degree of roundness with extremely low molding distortion, which inevitably increases the mold manufacturing cost. This is a factor that increases the cost of molded parts, which is a problem. Further, in the case of a product that can be expected to be produced in large numbers, even if the initial cost is high, the weight does not need to be large, but it is often difficult to produce a small number of products in terms of cost. In this regard,
In the lens barrel part configuration with the above-mentioned helicoid screw,
Since it is difficult to measure commonality with other models, it is difficult to measure the increase in production due to commonality, which is one of the reasons for the increase in cost.

Conventionally, the moving amount for focusing of the lens barrel is operated without using a helicoid screw.
As described in JP-A-115708, a movable lens barrel rotatably fitted via an operation ring to a fixed lens barrel attached to an optical device main body and movable in the optical axis direction is fixed. A guide boss provided at a plurality of locations of the movable lens barrel is slidably engaged with a guide notch of a guide boss provided at a plurality of locations around the optical axis to move in the optical axis direction, Further, a compression coil spring is provided between the guide boss and a spring receiving washer fitted to the guide column, so that the end face cam of the movable barrel and the cam contact surface of the operation ring elastically adhere to each other. Although it is known, since a compression coil spring is provided between the guide boss and the spring receiving washer of the guide column,
While there is a problem that the guide column has a long configuration along the optical axis direction, since the width of the guide notch of the guide boss that guides the guide column is reduced accordingly, the guide accuracy is reduced, and the fixed lens barrel is not provided. There is a problem that the movement accuracy of the movable lens barrel guided by the individual guide columns by the individual spring resilience of the individual compression coil springs is guided by the individual guide notches provided at a plurality of locations around the optical axis, In particular, in a focusing device for a lens barrel for a standard / wide-angle optical device in which the extension amount of the lens barrel is 1 mm or less, such as in the case of a standard lens of a CCTV camera lens or a wide-angle lens, the compression coil spring is surrounded by The configuration of the long guide column wound around the box causes an increase in size and is inappropriate.

[Means for Solving the Problems] Accordingly, the present invention has been made in view of the above-described problems, and has a fixed lens barrel 1 attached to an optical apparatus main body and a connecting ring 2 fixed to the fixed lens barrel 1. A lens barrel 3 which is rotatably fitted to the connecting ring 2 and is movable in the optical axis direction, and a rotation fixed to the lens barrel 3 via a guide hole penetrating the connecting ring 2 in the optical axis direction. A stop screw 10, an operating ring 4 sandwiched between the lens barrel 3 and the joint ring 2 and rotatably fitted to the lens barrel 3;
A lens mirror for an optical device, comprising: a plurality of operation surfaces 13 having a lead angle provided on a contact surface of the operation ring 4 and the lens barrel 3; In the torso focusing device, the lens barrel 3 is used as an elastic member for urging the contact portion 14 and the operation surface 13 in a direction of elastically contacting each other.
A leaf spring 9 sandwiched between said holding barrel 8 and said fixed barrel 1 by a holding ring 8 screwed into said lens barrel. It is.

[Operation] According to the focusing device for a lens barrel for a standard / wide-angle optical device according to the present invention described above, the lens barrel 3 is fixed to the connecting ring 2 fixed to the fixed barrel 1 by the detent screw 10. Can move in a straight line stably in the optical axis direction. Next, an operation ring 4 rotatably fitted to the lens barrel 3 is sandwiched between the lens barrel 3 and the joint ring 2, and has a lead angle provided on a contact surface between the operation ring 4 and the lens barrel 3. A leaf spring 9 is held between the fixed lens barrel 1 by a holding ring 8 screwed to the plurality of operation surfaces 13 and the abutting portions 14 which are respectively driven and abutted on the operation surfaces 13. Therefore, the operation surface 13 and the contact surface 14 can be reliably pressed against each other by sandwiching the leaf spring 9 in a small space, and the lens barrel 3 receives the elastic force of the leaf spring 9 uniformly around the optical axis. The elastic force is urged evenly through the presser ring 8 in the direction of bringing the operation surface 13 and the contact surface 14 into close contact with each other, so that the operation of moving the lens barrel 3 can be smoothly performed in a stable state. The lens barrel 3 side and the operation ring 4 side, which are receiving members that receive the repulsive force of the leaf spring 9 evenly, share the spring elasticity evenly and are hardly subject to wear. be able to.
In particular, in the case of a standard lens of a CCTV camera lens or a wide-angle lens, the extension amount of the lens barrel is 1 mm or less. Therefore, when the rotation angle of the operation ring 4 receiving the elastic clamping force of the leaf spring 9 is set, the lead angle is set. By setting the condition at a small angle such that the angle is 2 ° or less, for example, the operation ring 4 can be prevented from moving due to vibration, impact, and the like, and the lock screw and the like of the operation ring 4 are also deleted. be able to.

As described above, the present invention uses the repulsive force of the leaf spring 9 and the thrust of the operation surface 13 such as a cam surface having a lead angle in combination, especially in the case of a standard lens of a CCTV camera lens or a wide-angle lens. It is suitable for providing a focusing device for a lens barrel for a standard / wide-angle optical apparatus in which the amount of extension (movement) for focusing of the lens barrel 3 is 1 mm or less.

[Embodiment] The configuration of the present invention will be described below based on an embodiment implemented in the illustrated lens barrel for a CCTV camera.

1 is a partial side sectional view of a lens barrel for a CCTV camera to which the present invention is applied, FIG. 2 is a side sectional view of a main part thereof, and FIG. 3 is a front view of a main part of FIG. is there.

In FIG. 1, a lens barrel according to the present invention includes a fixed lens barrel 1 on a fixed body side mounted on a camera body, a joint ring 2 on the fixed body fixed to the fixed lens barrel 1, and a light ring on the joint ring 2. The lens barrel 3 and the connecting ring 2 on the moving body side which are supported so as to be able to move straight along the axial direction.
An operating ring 4 for rotating the lens barrel 3 which holds the optical system while rotating with respect to the lens barrel 3 to perform a focusing operation;
Frame 5, covering the outer periphery of the lens, front lens group 6 and rear lens frame 7, which are provided to hold the front lens group 11 and the rear lens group 12 in the lens barrel 3, a holding ring 8 described later, It is composed of a leaf spring 9, a rotation preventing screw 10 and the like.

The fixed lens barrel 1 on the fixed body side has a mount screw 1a to be mounted on the optical device main body, and is integrally attached to the optical device main body. The connecting ring 2 is rotatably fitted to the fixed lens barrel 1, and the mount positioning can be set at an arbitrary position.
Are fastened to fix and integrate the connecting ring 2. The connecting ring 2 is fitted on the outer periphery of the lens barrel 3 and supports the lens barrel 3 on the movable body side on the inner cylinder side so as to be movable in the optical axis direction.

In the illustrated embodiment, the connecting ring 2 on the fixed body rotatably supports the operating ring 4 on the outer cylinder side. Further, the connecting ring 2 has a guide hole for guiding the rotation preventing screw 10 implanted in the lens barrel 3 along the optical axis along the optical axis. In the lens barrel 3,
The front group lens frame 6 and the rear group lens frame 7 are integrally fixed, and are configured to hold an optical system including the front group lens 11 and the rear group lens 12.

Here, in the focusing device of the lens barrel for the standard / wide-angle optical device according to the present invention, in the case of the embodiment, the end surface of the operation ring 4 rotatably provided on the fixed body side and the end surface thereof. An operation surface 13 having a lead angle that increases and decreases corresponding to a predetermined rotation angle is provided on the one end surface side, and the operation surface 13 is provided on the other end surface side.
The lens barrel 3 is configured to advance and retreat along the optical axis by rotating the operation ring 4.

In the case of the embodiment, the operation surface 13 is provided on the operation ring 4, and the contact portion 14 is provided on the lens barrel 3. The operation surface 13 is
As shown in FIG. 3 and FIG. 3, the angle increases or decreases at a lead angle α °, and the increase or decrease width is a slope or a cam surface having Δd. On the contrary,
The contact portion 14 is configured as a spherical projection having at least a vertex in a spherical shape. In the case of the embodiment, the operation surface 13 is 180
Are provided at two places with an interval of °, and the corresponding contact parts
14 is also set at 180 ° intervals.

Further, a holding ring 8 having a flange-shaped holding portion is screwed and fixed to the lens barrel 3 inside the mounting screw 1a of the fixed barrel 1, and the holding portion and the corresponding holding ring are fixed. A leaf spring 9 as an elastic member is sandwiched between the fixed lens barrel 1 and the end surface of the connecting ring 2, and the operation interposed between the lens barrel 3 and the lens barrel 1 by the elastic force of the leaf spring 9. The surface 13 and the contact portion 14 are configured to elastically adhere to each other.

The same operation and effect can be obtained by providing the operation surface 13 on the end face of the lens barrel 3 and providing the contact portion 14 on the operation ring 4 side, contrary to the illustrated embodiment.

Further, in the illustrated embodiment, the operation ring 4 is provided rotatably on the fixed body side, and the end face of the operation ring 4 is provided in contact with the end face of the lens barrel 3 on the moving body side.
Differently from this, the operation ring 4 is provided rotatably on the moving body side, and the end surface of the operation ring 4 and the lens barrel 1 on the fixed body side.
And an operation surface having a lead angle that increases and decreases corresponding to a predetermined rotation angle is provided on the one end surface side, and a contact portion that abuts on the operation surface is provided on the other end surface side. The lens barrel 3 on the moving body side is provided by rotating the operation ring 4.
Can be configured to advance and retreat along the optical axis from the description of the above-described illustrated embodiment. In this case, similarly to the illustrated embodiment, the operation ring 4 includes a spherical protrusion. It is preferable to provide an abutting portion and provide an operation surface including a slope or a cam surface having a lead angle on the fixed body side.

Also in this device, the operation surface is formed of a slope or a cam surface having at least two or more lead angles, while the abutment portion is the same number as the slope or the cam surface, and at least the top of the spherical projection is rounded. It is preferable to configure the unit.

In order to assemble the apparatus having the configuration of the above-described illustrated embodiment, first, the position is set so that the operation surface 13 formed of the inclined surface or the cam surface of the operation ring 4 abuts on the spherical projection 14 of the lens barrel 3. The operating ring 4 is also fitted while the spigot 2 and the spigot part of the lens barrel 3 are fitted. And the detent screw
10 is passed through the guide hole of the connecting ring 2 and screwed to the lens barrel 3. Next, the fixed lens barrel 1 is fitted into the spigot part of the connecting ring 2 and fixed with the set screw 1b, the leaf spring 9 as an elastic member is inserted inside the fixed lens barrel 1, and the holding ring 8 is attached to the lens barrel 3. Is fixed to the fixed barrel 1 and the barrel 3, and the repulsive force of the leaf spring 9 is fixed to the fixed barrel 1 and the barrel 3.
Is constantly pressed in a direction to narrow the gap, and the resilient force of the leaf spring 9 causes the spherical projection 14 of the lens barrel 3 and the inclined surface or the cam surface 13 of the operation ring 4 to come into close contact with each other. Next, the front lens group frame 6 and the rear lens group frame 7 are fixed to the lens barrel 3, and the decorative frame 5 is fixed by screws (not shown), thus completing the assembly.

When a rotation operation is given to the operation ring 4 in this state, the operation ring 4
The point of contact between the operation surface 13 and the spherical projection 14 of the lens barrel 3 is defined as the point A at the infinite position of the optical system and the point B at the shortest photographing distance position. Then, the operation surface 13 is moved by an amount of inclination Δd of the operation surface 13 composed of a slope or a cam surface.
At this time, the contact point, that is, the lens barrel 3 moves by overcoming the repulsive force of the leaf spring 9 of the elastic member.
Is rotated in the opposite direction, the lens barrel 3 is retracted by Δd using the repulsive force of the leaf spring 9 as a thrust. This Δd
The extension and retraction of the amount is the amount of movement for focusing the lens barrel.

Although not shown in the drawings, the rotation stopper at the point A at the infinity position and the point B at the shortest photographing distance of the operation ring 4 may be provided separately with a stopper member, or may be provided with spherical members at both ends of the inclined surface or the cam surface. The root member of the projection can be used together with the stopper. In addition, the spherical projection is not limited to an acute angle at least at the apex portion, and may be a rounded projection so that the contact portion can be smoothly moved, and the root that does not contact is limited to a corner or a round. is not.

In this embodiment, the lens barrel 3 has a spherical projection and the operation ring 4 has a slope or a cam surface. However, the lens barrel 3 has a slope or a cam surface, and the operation ring 4 has a spherical or cam surface. The same effect can be obtained even when the projections are provided. Further, the operation ring is held on the fixed body side in this embodiment even when the operation ring is held. The same effect can be obtained by providing a correlation between the configuration of the spherical projection and the slope or the cam surface on the body side and the operation ring 4, and the configuration is not limited to the configuration shown in the drawings.

[Effects] As described above, according to the focusing apparatus for the lens barrel for the standard / wide-angle optical device according to the present invention, the fixed barrel 1 attached to the optical device body and the fixed barrel 1 are fixed to the fixed barrel 1. A connecting ring 2, a lens barrel 3 rotatably fitted to the connecting ring 2 and movable in the optical axis direction, and a guide hole penetrating in the optical axis direction of the connecting ring 2 to the lens barrel 3. A rotation-stop screw 10 to be fixed, an operation ring 4 sandwiched between the lens barrel 3 and the joint ring 2 and rotatably fitted to the lens barrel 3; A plurality of operation surfaces 13 having a lead angle provided on the contact surface
And an abutting portion 14 that is driven and abuts on each of the operation surfaces 13 in a focusing device for a lens barrel for an optical device, in a direction in which the abutting portion 14 and the operation surface 13 are elastically adhered to each other. As a biasing elastic member, a leaf spring 9 is sandwiched between the holding barrel 8 and the fixed lens barrel 1 by a holding ring 8 screwed to the lens barrel 3 so as to be fixed to the fixed lens barrel 1. There is an effect that the lens barrel 3 can be stably linearly moved in the optical axis direction by the rotation preventing screw 10 with respect to the joint ring 2, and at the same time, the operation ring 4 rotatably fitted to the lens barrel 3 is connected to the lens barrel. A plurality of operating surfaces 13 having a lead angle provided on the abutting surface of the operating ring 4 and the lens barrel 3, which are held between the operating ring 3 and the connecting ring 2; The contact portion 14 is attached by holding a leaf spring 9 between the fixed barrel 1 and a holding ring 8 screwed into the lens barrel 3. Therefore, there is an effect that the leaf spring 9 is sandwiched in a small small space and the operation surface 13 and the contact surface 14 can be reliably pressed against each other, and the lens barrel 3 is evenly distributed around the optical axis. The elastic force is uniformly urged in the direction of bringing the operation surface 13 and the contact surface 14 into close contact with each other via the presser ring 8 receiving the elastic force, and the moving operation of the lens barrel 3 is performed smoothly in a stable state. There is an effect that can be. The lens barrel 3 and the operating ring 4, which are receiving members that receive the repulsive force of the leaf spring 9 evenly,
The side has a structure in which the spring elasticity is evenly distributed and bears, and is hardly subject to abrasion. Therefore, there is an effect that both sides can be made of resin. In particular, in the case of a standard lens or a wide-angle lens for a CCTV camera, since the extension amount of the lens barrel is 1 mm or less, the operating ring 4 receiving the elastic clamping force of the leaf spring 9 is used.
In setting the rotation angle of the lead angle, for example, 2 °
By setting the condition at a small angle as described below, it is possible to prevent the operation ring 4 from moving due to vibration, impact, and the like, and it is possible to eliminate the lock screw and the like of the operation ring 4. .

As described above, the present invention uses the repulsive force of the leaf spring 9 and the thrust of the operation surface 13 such as a cam surface having a lead angle in combination, especially in the case of a standard lens of a CCTV camera lens or a wide-angle lens. It is suitable for providing a focusing device for a lens barrel for a standard / wide-angle optical device in which the extension amount (movement amount) for focusing of the lens barrel 3 is 1 mm or less. The focusing operation of the lens barrel 3 can be performed by using both the repulsive force of the leaf spring 9 and the thrust of the operation surface 13 such as a cam surface having a lead angle without using it. In addition, there is an effect that it is possible to provide a focusing device in which individual components can be formed in a simple shape and can be easily made of plastic.

[Brief description of the drawings]

FIG. 1 is a partial side sectional view of a lens barrel for a CCTV camera to which the present invention is applied, FIG. 2 is a side sectional view of a main part thereof, and FIG. 3 is a front view of a main part of FIG. FIG. 4 is an enlarged explanatory view of a main part of FIG. DESCRIPTION OF SYMBOLS 1 ... Fixed lens barrel 2 ... Joint ring 3 ... Barrel 4 ... Operation ring 5 ... Decoration frame 6 ... Front group lens frame 7 ... Rear group lens frame 8 ... Holding ring 9 ... Leaf spring (Elastic member) 10 Lock screw 13 Operation surface (slope or cam surface) 14 Contact part (spherical projection)

Claims (1)

(57) [Scope of request for utility model registration] 1. A fixed lens barrel 1 attached to an optical apparatus main body.
A connecting ring 2 fixed to the fixed lens barrel 1, a lens barrel 3 rotatably fitted to the connecting ring 2 and movable in the optical axis direction, and penetrating in the optical axis direction of the connecting ring 2. The lens barrel 3 through the guide hole
Screw 10, which is fixed to the lens barrel, the lens barrel 3, and the joint ring 2.
An operating ring 4 sandwiched between the operating ring 4 and rotatably fitted to the lens barrel 3, a plurality of operating surfaces 13 having a lead angle provided on a contact surface between the operating ring 4 and the lens barrel 3, In the focusing device for a lens barrel for an optical device, comprising a contact portion 14 that is driven and contacted with each of the operation surfaces 13, the contact portion 14 and the operation surface 13 are biased in a direction in which the operation surface 13 is elastically adhered. A lens barrel for a standard / wide-angle optical device, wherein a leaf spring 9 is provided between the fixed barrel 1 and a holding ring 8 screwed to the barrel 3 as an elastic member. Focusing device