JPH11326732A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new lens device capable of reducing the production cost and the assembly cost of parts, having little dispersion and being homogenized, and preventing a lens from being distorted by having a structure which does not require a screw part in a lens device constituted by fixing the lens in a lens holder. SOLUTION: The large-diameter holding part 11 of the lens holder 10 fits and holds the large-diameter lens 1, and the small-diameter holding part 12 thereof fits and holds the small-diameter lens 2. An annular recessed groove 15 is formed on the inner peripheral surface of the holding part 11, and an annular recessed groove 16 is formed on the inner peripheral surface of the holding part 12. Pressing surfaces 21 and 31 pressing the lenses 1 and 2 to the lens holder 10 and abutting on the lenses 1 and 2 are formed at the inner periphery side parts of lens fixing frames 20 and 30. Six projection parts 22 and 32 are formed to project at the intervals of an equal angle in the revolving direction on the outer peripheral surfaces of the frames 20 and 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens device, and more particularly to a fixing structure of a device having a lens and a lens holder for holding the lens.

[0002]

2. Description of the Related Art Conventionally, a lens holder for holding various lenses has been used. A lens is housed inside a lens holder, and a lens fixing frame is mounted on the lens holder to be held inside the lens holder. The fixed lens is configured to form a lens device. For example, CCD
In the case of a small lens device used for a camera or the like, a plastic lens manufactured by injection molding of a synthetic resin or the like is accommodated, and a synthetic resin cylindrical lens holder capable of holding the plastic lens in a predetermined posture is provided. ,
A synthetic resin lens fixing frame provided with a screw portion so as to be screwed into the lens holder is formed by injection molding or the like. In this case, after holding the plastic lens in a predetermined posture in the lens holder, the lens fixing frame is screwed into the lens holder, so that the plastic lens is pressed against the lens holder by the lens fixing frame, and the plastic lens is placed in the lens holder. Is held between the holding surface of the lens and the pressing surface of the lens fixing frame.

[0003]

However, when the lens holder and the lens fixing frame are manufactured as described above, since the threaded portion must be formed, the molding and processing costs are increased, and moreover, Since this screw portion is the most important structure for fixing the lens, a high-precision screw shape is required, so that the cost is further increased. In particular, resin parts are inevitable in pursuit of manufacturing cost reduction.However, when the lens holder and the lens fixing frame are made of synthetic resin, a mold structure is needed to form the threaded portions of both. Since the mold becomes complicated and the accuracy of the screw shape is also required, the cost of the mold increases, and the effect of reducing the manufacturing cost is reduced.

Further, when the lens holder and the lens fixing frame are connected by screwing, it is usually necessary to turn the lens fixing frame several times or more before tightening, so that it takes a long time to assemble, so that the manufacturing cost is reduced. Becomes difficult. Furthermore, since the lens is fixed by screwing, the screwing torque varies from device to device or from worker to worker, making it difficult to produce a uniform product. The lens may be subjected to uneven stress in the circumferential direction of the screw, causing a problem that lens distortion occurs.

Accordingly, the present invention has been made to solve the above-mentioned problems. In a lens device in which a lens is fixed to a lens holder, a structure that does not require a screw portion is used, thereby reducing the manufacturing cost and assembly cost of parts. An object of the present invention is to provide a novel lens device which can be reduced, is uniform with little variation, and does not cause distortion in the lens.

[0006]

Means taken by the present invention for solving the above-mentioned problems include a lens, a lens holder for holding the lens, and a lens holder which is engaged with the lens holder and is attached to the lens holder. A lens fixing frame for fixing the held lens, a projection is formed on one of the lens holder and the lens fixing frame, and a concave groove is formed on the other to fit the projection. Then, the lens holder and the lens fixing frame are fitted to each other, and the protrusions and the concave grooves are fitted to each other, whereby an elastic restoring force generated by the fitting between the lens holder and the lens fixing frame. Wherein the lens device is configured to sandwich the lens. The elastic restoring force is a stress generated by the elastic deformation of at least one of the lens holder and the lens fixing frame due to the fitting of the projection and the concave groove.

According to this means, the projection and the concave groove are fitted by fitting the lens fixing frame into the lens holder while holding the lens in the lens holder. Are engaged with each other and the lens is fixed, so that the assembling work of the lens device is extremely easy, and the lens is fixed by the elastic restoring force generated by the fitting. The force can be kept constant and a homogeneous lens device can be manufactured.

Here, a plurality of the protrusions are formed at equal angular intervals on an outer peripheral surface formed as a cylindrical outer surface of one of the lens holder and the lens fixing frame, and the concave groove is formed on the other side. It is preferable that it is formed in an annular shape on the inner peripheral surface configured as a cylindrical inner surface.

According to this means, since the fitting portion is the cylindrical outer surface having a plurality of protrusions in the circumferential direction and the cylindrical inner surface having the annular concave groove formed in the circumferential direction, the lens holder and the lens fixing member are fixed. Since the frame can be fitted in any rotation posture around the axis, the positioning work in the rotation direction becomes unnecessary, so that the assembling work is further facilitated and unnecessary distortion in the rotation direction is caused. And a uniform fixing force can be applied to the lens.

In each of the above means, the projection is provided with an inclined outer surface facing in a direction opposite to the fitting direction, and the concave groove is provided with an inclined inner surface facing in the fitting direction. When the inclined outer surface portion and the inclined inner surface portion are in contact with each other in the fitted state with the concave groove, the elastic restoring force is applied to the lens at the contact portion between the inclined outer surface portion and the inclined inner surface portion. Desirably, it is configured so that it can be converted into a clamping pressure.

According to this means, when the inclined outer surface portion of the projection and the inclined inner surface portion of the concave groove come into contact with each other, the elastic restoring force is converted into the stress in the axial direction at the contact portion, and the lens holder and the lens are moved. Since it is configured to have a clamping force on the lens with the fixed frame, a stable clamping force can be exerted on the lens with a margin corresponding to the width formed between the inclined outer surface portion and the inclined inner surface portion, so that the lens can be surely held. Can be fixed.

In each of the above means, it is desirable that the lens holder and the lens fixing frame are made of synthetic resin. According to this means, the manufacturing cost can be reduced by the synthetic resin, and since only the protrusions and the concave grooves need to be formed, the die cost can also be suppressed.

Further, in each of the above means, it is preferable that a fitting direction of the lens fixing frame to the lens holder coincides with an optical axis direction of the lens. According to this means, since the fitting direction of the lens holder and the lens fixing frame coincides with the optical axis direction of the lens, the lens can be reliably positioned in the optical axis direction.

Next, a lens and a lens holder for holding the lens are provided, and a projection is formed on one of the lens and the lens holder, and a recess fit on the projection is formed on the other. A groove is formed, the lens and the lens holder are fitted to each other, and the projection and the concave groove are fitted to each other, so that the lens and the lens holder are connected to each other by an elastic restoring force generated by the fitting. A lens device configured to be fixed.

In this case, it is preferable that a flange-shaped mounting portion is formed on an outer peripheral portion of the lens, and the projection or the concave groove is formed integrally with the mounting portion. According to this means, the lens can be securely fixed without affecting the optical surface of the lens by forming the projection or the concave groove on the mounting portion.

In the sixth and seventh aspects, a plurality of the protrusions are formed at equal angular intervals on an outer peripheral surface formed as a cylindrical outer surface of one of the lens holder and the lens, It is preferable that the concave groove is formed in an annular shape on an inner peripheral surface configured as the other cylindrical inner surface. In addition, an inclined outer surface portion facing the opposite side to the fitting direction is provided on the protrusion, and an inclined inner surface portion facing the fitting direction is provided on the concave groove, and the fitting state between the protrusion and the concave groove is provided. In such a manner that the inclined outer surface portion and the inclined inner surface portion are in contact with each other, so that the elastic restoring force can be converted into a clamping force on the lens at a contact portion between the inclined outer surface portion and the lens fixing frame. It is desirable to be configured. Further, it is desirable that the lens holder and the lens are made of synthetic resin, and that a fitting direction of the lens into the lens holder coincides with an optical axis direction of the lens.

In all of the above cases, the lens is preferably a molded resin lens, and a lens holder may be provided with a plurality of lenses, particularly from both sides of the lens holder. A lens may be mounted.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the lens device according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is an exploded structural view showing the structure of the lens device according to the first embodiment of the present invention. In the figure, the portion above the dashed line indicates a cross section, and the portion below the dashed line indicates a side surface. The lens holder 10 shown at the center and the lens fixing frames 20 and 30 shown at the right and left are both formed by molding a synthetic resin such as polycarbonate or ABS resin by a resin molding method such as injection molding. is there. It is preferable that the lens holder 10 and the lens fixing frames 20, 30 have a color tone such as black that is hard to transmit light. On the other hand, the lenses 1 and 2 held inside the lens holder 10 are both formed by molding a transparent synthetic resin such as an acrylic resin by a resin molding method such as injection molding.

The lens holder 10 has a cylindrical shape as a whole. The lens holder 10 has a large-diameter holding portion 11 having a slightly larger diameter at one end in the axial direction and a small-diameter holding portion 12 at the other end. A step portion 13 for fitting and holding the lens 1 is formed near the center of the inside of the large-diameter holding portion 11 so that the optical axis of the large-diameter lens 1 coincides with the axis of the lens holder 10. Near the center, there is formed a step portion 14 for fitting and holding the lens 2 such that the optical axis of the small-diameter lens 2 matches the axis of the lens holder 10. An annular concave groove 15 is formed on the inner peripheral surface of the large-diameter holding portion 11, and an annular concave groove 16 is formed on the inner peripheral surface of the small-diameter holding portion 12. In addition, the concave grooves 15 and 16 may be divided into a plurality in the circumferential direction.

Each of the lenses 1 and 2 comprises an inner peripheral portion on which a predetermined optical surface is formed, and an outer peripheral portion formed outside the inner peripheral portion. Positioning steps 1a and 2a are formed so as to match the portions 13 and 14, and positioning surfaces 1b and 2b are formed on the other side of the outer peripheral portion so as to be pressed by the lens fixing frames 20 and 30. Have been. Lens 1 is a concave lens, and lens 2 is a convex lens.

Each of the lens fixing frames 20 and 30 is an annular body, and its inner peripheral portion is in contact with positioning surfaces 1 b and 2 b formed on the lenses 1 and 2, and the lenses 1 and 2 are attached to the lens holder 10. Pressing surfaces 21 and 31 for pressing against them are formed. On the outer peripheral surfaces of the lens fixing frames 20 and 30,
The six projections 22 and 32 are integrally formed so as to protrude at equal angular intervals, that is, at intervals of 60 degrees in the circumferential direction. Although the number of protrusions and the formation interval are arbitrary, it is preferable that the number of protrusions is equal to or more than three, particularly from the viewpoint that they can be fitted evenly.

In this embodiment, after the lenses 1 and 2 are set in the lens holder 10 as shown, the lens fixing frame 2
By pushing 0, 30 in the axial direction respectively,
The projections 22 and 32 are fitted into the concave grooves 15 and 16, whereby the lens fixing frames 20 and 30 are fixed to the lens holder 10. At this time, the pressing surfaces 21 and 31 of the lens fixing frame abut against the positioning surfaces 1b and 2b of the lens, and press the lens by the elastic restoring force generated by the elastic deformation of the lens holder and the lens fixing frame caused by the fitting. , Lens 1,2
Is clamped and fixed between the lens holder 10 and the lens fixing frames 20 and 30. The grooves 15, 16 and the projections 22,
At the time of fitting with 32, at least one of the lens holder 10 and the lens fixing frames 20, 30 needs to be elastically deformed. In the present embodiment, since both the lens holder and the lens fixing frame are formed of a resin material, both are slightly elastically deformed together, and the projection is fitted into the concave groove.

The projections 22 and 32 have substantially the same shape, and the grooves 15 and 16 also have substantially the same shape. FIGS. 4A and 4B show the shapes of the concave groove and the protrusion in detail. FIG. 4A shows a cross section along a plane extending in the fitting direction of the lens holder 10 and the lens fixing frame 30, and FIG. 4B shows a cross section along a plane orthogonal to the fitting direction of the lens holder 10. . A top surface 32 a having a height H (for example, H = 0.1 to 0.15 mm) is formed on the protrusion 32, and the top surface 32 a
0 has a cylindrical outer surface that is substantially concentric with the outer peripheral surface. The width T of the top surface portion 32a in the fitting direction is, for example, 0.3 mm.
It is. The outer surface 32b is inclined in the fitting direction of the top surface 32a.
The outer peripheral surface of the lens fixing frame ahead of the inclined outer surface portion 32b is an introduction taper outer surface 30a inclined by ψ1 (for example, ψ1 = about 10 degrees) toward the fitting direction.
The inclined outer surface portion 32b has a difference of $ 2 from the tapered surface 30a.
(For example, ψ2 = approximately 20 degrees). The outer peripheral surface other than the tapered surface has a surface inclined at approximately 30 degrees. On the other hand, the inclined outer surface portion 32c formed on the opposite side of the fitting direction with respect to the top surface portion 32a is
(For example, ψ3 = about 45 degrees).

The groove 16 has a depth D (for example, D = 0.1 to
A bottom surface 16a of 0.15 mm) is formed, and the inner surface of the bottom surface 16a is formed in a cylindrical inner surface shape concentric with the inner peripheral surface of the small diameter holding portion 12. The width of the bottom portion 16 in the fitting direction is the same as the above-mentioned T. An inclined inner surface portion 16b is formed in the fitting direction of the bottom portion 16a. The inclined inner surface portion 16b has an inclination angle of θ1 (for example, θ1 = about 45 degrees) with respect to the inner peripheral surface of the small-diameter holding portion 12. Have. Bottom part 16
An inclined inner surface portion 16c is also formed in the anti-fitting direction of a, and is inclined by θ2 (for example, θ2 = about 45 degrees) with respect to the inner peripheral surface. At the opening edge of the small-diameter holding portion 12, an introduction taper inner surface 12a inclined outward is formed.

As shown in FIG. 4B, inclined side surfaces 32d and 32e are formed on both sides of the outer peripheral surface of the lens fixing frame 30 in the circumferential direction with respect to the top surface 32a of the projection 32. These inclined side surface portions 32d and 32e are formed symmetrically to each other, and the inclined side surface portions 32d and 32e are formed.
Is an angle δ (for example, δ = 60 degrees). The surface of the top surface portion 32a is formed in a cylindrical outer surface concentric with the outer peripheral surface of the lens fixing frame 30, and is curved in the circumferential direction of the outer peripheral surface. In FIG. 4B, the protrusion 32
In order to clarify the shape, the width and height of the protrusion 32 in the circling direction are drawn larger than the outer diameter of the lens fixing frame 30.

In this embodiment, when the lens fixing frame 30 is pushed into the small-diameter holding portion 12, the introduction taper outer surface 30a of the lens fixing frame 30 is
a, the lens fixing frame 30 is guided into the small diameter holding portion 12 by the pressing force. Next, the inclined outer surface portion 32b comes into contact with the introduction taper inner surface 12a, and both the small-diameter holding portion 12 and the lens fixing frame 30 start to be elastically deformed. In a state where the projection 32 and the groove 16 are in the fitted state and the lens 2 is securely fixed by the lens holder 10 and the lens fixing frame 30,
As shown in FIG. 5, the inclined inner surface portion 16c and the inclined outer surface portion 32c
Are in contact with each other slightly off. At this time, the elastic restoring force F +, between the small diameter holding portion 12 and the lens fixing frame 30,
A stress acting to restore the top surface portion 32a of the projection 32 and the bottom surface portion 16a of the concave groove 16 is acting as F−, and the elastic restoring forces F + and F− are applied to the inclined inner surface portion 16c. By the contact portion between the lens 2 and the inclined outer surface portion 32c, the lens 2 is converted into squeezing forces G + and G- in the axial direction (equal to the optical axis direction in the present embodiment), and the lens 2 is squeezed and held.

FIG. 2 shows a modification of the above embodiment. In this modification, the lens fixing frames 50 and 60 are configured to be engageable with the lens holder 40, and the lenses 1 and 2 are held and fixed in the same manner as in the above-described structure. Groove 46 formed in holding portion 42
Is configured so as to fit with the projection 62 formed on the lens fixing frame 60. However, contrary to the above embodiment, six projections 45 are formed in the circumferential direction on the outer periphery of the large-diameter holding portion 41 of the lens holder 40, and these projections 45 are formed on the inner peripheral surface of the lens fixing frame 50. The difference is that it is configured to fit into the annular groove 52.

FIG. 3 shows still another embodiment. In this embodiment, a flange-shaped mounting portion 3a provided around the optical surface portion is formed integrally with the lens 3, and a plurality of protrusions 3 are formed on an outer peripheral surface portion 3b of the mounting portion 3a.
c is formed to protrude. On the other hand, the annular lens holder 70
Are formed with a positioning surface 71 for abutting against the mounting portion 3a and positioning, and a concave groove 72 configured to fit into the projection 3c. In this embodiment, the lens 3
By pressing the mounting portion 3a into the inside of the lens holder 70, the projection 3c and the concave groove 72 are fitted, and the mounting portion 3a is pressed against the positioning surface 71 by the elastic restoring force generated by this fitting. The lens 3 is reliably positioned and held with respect to the lens holder 70.

In each of the above structures, the lens holder and the lens fixing frame or the lens holder and the lens are fitted and fixed by fitting the plurality of projections and the annular groove. Are not limited to the combinations of the shapes and arrangements described above as long as they have a structure that fits each other. However, it is preferable that the projection is divided into a plurality of portions and the concave groove is formed integrally since the distortion of the lens holder and the lens can be reduced. Further, the protrusion and the concave groove may be formed on either the lens holder and the lens fixing frame, or the lens holder and the lens.

[0030]

As described above, the projection and the concave groove are fitted by fitting the lens fixing frame into the lens holder while holding the lens in the lens holder, thereby fixing the lens holder and the lens. Since the frame and the lens are engaged with each other and the lens is fixed, the assembling work of the lens device is extremely easy, and the lens is held by the elastic restoring force generated by the fitting, The lens fixing force can be kept constant, and a uniform lens device can be manufactured.

[Brief description of the drawings]

FIG. 1 is an exploded structural view showing a structure of an embodiment of a lens device according to the present invention.

FIG. 2 is an exploded structural view showing a modification of the embodiment.

FIG. 3 is an exploded structural view showing a structure of another embodiment.

4A is an enlarged cross-sectional view showing the structure of the fitting portion of the embodiment shown in FIG. 1 in a section along the fitting direction, and FIG. Figure (b)
It is.

5 is an enlarged cross-sectional view showing a structure of a fitting portion in a fitting state of the embodiment shown in FIG. 1 in detail along a section along a fitting direction.

[Explanation of symbols]

 1, 2, 3 lens 3a mounting portion 3b outer peripheral surface 3c, 22, 32, 45, 62 projecting portion 15, 16, 46, 52, 72 concave groove

Claims (7)

[Claims] 1. A lens comprising: a lens; a lens holder for holding the lens; and a lens fixing frame engaged with the lens holder and fixing the lens held by the lens holder. A protrusion is formed on one of the holder and the lens fixing frame, and a concave groove is formed on the other to fit the protrusion, and the lens holder and the lens fixing frame are fitted to each other, and the protrusion is formed. A lens device characterized in that the lens holder and the lens fixing frame hold the lens with an elastic restoring force generated by fitting by fitting a portion and the concave groove to each other. 2. The concave groove according to claim 1, wherein a plurality of the protrusions are formed at equal angular intervals on an outer peripheral surface formed as a cylindrical outer surface of one of the lens holder and the lens fixing frame. Is a lens device formed in an annular shape on an inner peripheral surface configured as the other cylindrical inner surface. 3. The method according to claim 1, wherein the projection has an inclined outer surface facing the opposite side to the fitting direction, and the concave groove has an inclined inner surface facing the fitting direction.
In the fitting state of the projection and the concave groove, the inclined outer surface portion and the inclined inner surface portion come into contact with each other, so that the elastic restoring force makes contact between the inclined outer surface portion and the inclined inner surface portion. A lens device characterized in that it is configured to be able to convert to a clamping force on the lens at a portion. 4. One of claims 1 to 3
In the paragraph, the lens holder and the lens fixing frame are made of synthetic resin. 5. The method according to claim 1, wherein:
In the paragraph, the fitting direction of the lens fixing frame to the lens holder coincides with the optical axis direction of the lens. 6. A concave groove provided with a lens and a lens holder for holding the lens, wherein one of the lens and the lens holder is formed with a projection, and the other is fitted with the projection. Is formed, the lens and the lens holder are fitted to each other, and the projection and the groove are fitted to each other, whereby the lens and the lens holder are fixed to each other by an elastic restoring force generated by the fitting. A lens device characterized in that the lens device is configured to be operated. 7. The lens according to claim 6, wherein a flange-shaped mounting portion is formed on an outer peripheral portion of the lens, and the protrusion or the concave groove is formed integrally with the mounting portion. apparatus.