JPH0894901A - Optical lens barrel - Google Patents

Abstract

PURPOSE: To provide an optical lens barrel which is effective for miniaturizing a camera and the like and whose assembling workability is excellent. CONSTITUTION: This is the optical lens barrel constituted so that driving force is transmitted by an outer barrel member 3 engaged with an inner barrel housed in a fixed barrel 2 fixed to a main body 1 and an image is formed on an rectangular plane image forming surface arranged backward. Then, partially notched parts 2b and 3b are respectively formed at the end parts of the barrel 2 and the barrel member 3 on the image forming surface side according to four corners in the diagonal direction of the image forming surface. Besides, the barrel member 3 is interposed between the barrel 2 by a regulation member 4 provided with a regulation part brought into contact with the end surface of the barrel member 3 on the image forming surface side and an extended part 4b extended forward from the regulation part according to four corners in the diagonal direction so as to cover the notched parts and coupled to the fixed barrel 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical lens barrel such as a lens barrel unit structure of a camera which is effective for reducing the diameter of the lens barrel.

[0002]

2. Description of the Related Art FIG. 6 is a camera fixed to a camera body 1 in which a lens barrel for accommodating a lens barrel when retracted has a tubular shape. Upon request, the camera body 1 to expose the image on the film surface
It shows a state in which the length is shorter than the diagonal length of the aperture 1c opened at the bottom. In FIG. 7, a cross-sectional view taken along a plane including the diagonal line of the aperture and the optical axis is shown in FIG. Reference numeral 12 is a final curved surface of the photographing lens, and 13 is a luminous flux that forms an image at a diagonal apex of the photographing screen 14. As can be seen from the figure, when the outer diameter of the fixed barrel 2 is made shorter than the length of the diagonal line of the aperture 1c, part of the effective light flux passing through the four corners of the aperture is blocked by the fixed barrel.

For this reason, conventionally, the inner diameter 2f of the fixed barrel 2 is made longer than the length of the diagonal line of the aperture 1c, or at least the outer diameter of the fixed barrel 2 is made longer than the length of the diagonal line of the aperture so that the inner diameter portion is larger. The portions where the effective luminous flux is blocked at the four corners were made into escape shapes.

By the way, in a camera capable of switching between a standard screen and a trimming screen, a trimming mask blade arranged in the aperture of the main body is located at a predetermined position in the optical axis direction (usually between the aperture and the lens barrel). It was held by the holding member so that it would move with.

Further, the mask blade switching mechanism is usually arranged in the same plane as the mask blade.

[0006]

However, since the size of the aperture is uniformly determined by the size of the film, the above-mentioned conventional method limits the diameter of the fixed barrel to the length of the diagonal line of the aperture, and There was a limit to the reduction of diameter.

Therefore, the outer diameter of the fixed cylinder is made shorter than the length of the diagonal line of the aperture, and at the same time, the four corners on the film side end of the fixed cylinder which cut off the light flux passing through the four corners of the aperture are cut out. Although the diameter of the lens barrel can be further reduced, the first problem is that external light leaking from the gap between the camera body and the lens barrel enters the lens barrel through the notch and reaches the film. There is a problem of exposure.

Here, if the outermost peripheral portion of the lens barrel is a fixed cylinder, the outermost peripheral portion does not need to be a cylinder, so the four corners of the film surface side end portion are made irregular, for example, rectangular to eliminate the notch. It is also possible. On the other hand, in the case of a drive ring that drives the tubular member inside the fixed barrel by fitting the outermost peripheral portion to the outer periphery of the fixed barrel and rotating around the optical axis, the fixed ring is not fixed. If the lens barrel is made so small that the notches must be provided in the tube and the four corners of the drive ring must also be provided, the notches must be provided to prevent light leakage from the notches. A member for covering up is required.

Next, as a second problem, by providing cutouts at the four corners, the strength of the fixed barrel is lowered, and the connection with the lens barrel for helicoid coupling provided inside the fixed barrel is released. There is a problem that it becomes easier.

On the other hand, in a camera capable of switching between the standard screen and the trimming screen, a pressing member for the mask blade is required, so that the number of parts is increased and the cost is increased.

Further, if the mask blade switching mechanism is arranged in the same plane as the mask blade, the switching mechanism must be arranged in any of the upper, lower, left, and right spaces of the aperture, which hinders miniaturization of the camera. Therefore, it is possible to effectively use the space by arranging the switching mechanism on the side surface of the main body aperture section spool side or the side surface of the cartridge chamber side, but since it is the side surface inside the main body,
The mold splitting structure of the attachment holding part of the switching mechanism becomes complicated,
Increasing die cost and lowering assembly work are inevitable.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to effectively reduce the size of a camera and to improve the assembling workability. It is an object of the present invention to provide an optical lens barrel such as.

[0013]

According to a first aspect of the present invention, there is provided a structure for realizing an object of the present invention, wherein an inner cylindrical member housed in a cylindrical fixed cylinder fixed to a main body is provided. In the optical lens barrel that transmits the driving force by the outer cylinder member fitted to the outer periphery of the fixed cylinder and forms an image on the image plane of the rectangular plane arranged rearward, the image formation of the fixed cylinder and the outer cylinder member Partial notches are formed at the end portions on the surface side corresponding to the four corners in the diagonal direction of the image forming surface, and the restricting portion in contact with the end surface on the image forming surface side of the outer tubular member and the diagonal portions are formed. The outer cylinder member of the fixed cylinder is extended by a restriction member that extends toward the front from the restriction portion so as to cover the notch corresponding to the four corners of the direction, and has an extension portion that is coupled to the fixed cylinder. It is an optical lens barrel characterized by being sandwiched between them. In this configuration, the extension portion of the restricting means shields harmful light entering through the notches formed at the four corners of the fixed cylinder and the outer cylinder member, and keeps the outer cylinder member at a fixed position in the optical axis direction with respect to the fixed cylinder. Can be kept.

According to a second aspect of the present invention, in the first aspect, the regulating portion of the regulating member is fitted with the image plane side end of the fixed barrel and holds the fixed barrel. By virtue of the configuration in which the restriction member is formed, the restriction member serves as a reinforcing means for reinforcing the end portion of the fixed cylinder.

Further, as described in claim 3, claim 1
Alternatively, in the second aspect, the light shielding member for changing the screen size with respect to the image formation screen is arranged between the restricting portion of the restricting member and the main body, and the restricting unit is, for example, a mask blade for trimming. It plays a role as a holding means for holding the light shielding member to regulate the position.

Further, according to a fourth aspect of the present invention, in the third aspect, the mechanism for switching the light shielding member is provided and the holding portion is provided on the side surface of the regulating member. The portion also serves as a holding means for holding the switching mechanism of the light shielding member.

Further, as described in claim 5, in the structure characterized in that in claim 1, 2, 3 or 4, the main body is a camera, which can be effectively used for the camera and can save the camera. Space and cost reduction can be achieved.

[0018]

【Example】

(First Embodiment) FIG. 1 is a view showing the schematic arrangement of a first embodiment of the present invention, in which 1 is a camera body, 2 is a fixed cylinder, 3 is a drive ring, and 4 is a regulating member. It is the lens barrel base plate.
The configuration and function of each member will be described below with reference to FIG.

The main body 1 has a patrone chamber 1a for accommodating a photographic film cartridge on the left side and a spool chamber 1b for accommodating and accommodating a film having been photographed on the right side, and an exposure opening at an intermediate portion of both chambers. Is provided with an aperture 1c. The fixed barrel 2 has a flange 2a, which is a mounting portion for the main body 1, on the front side, and four cutouts 2b are provided at the end portion on the film surface side in order to pass the light fluxes at the four corners of the aperture. Further, the fixed barrel 2 internally holds a lens barrel (not shown) holding a photographing lens group for forming a subject image, and guides movement of the lens barrel in the optical axis direction.

The drive ring 3 has a driven gear 3a which meshes with a drive gear (not shown) on the outer circumference, is fitted to the outer diameter of the fixed barrel 2 and receives the driving force of the drive gear to rotate around the optical axis. Then, the lens barrel is moved in the optical axis direction by a known combination of a straight-movement key and a cam. Similarly to the fixed barrel 2, the drive ring 3 is provided with four cutouts 3b at the film side end. However, since the drive ring 3 rotates around the optical axis, the cutout 3b is a cutout of the fixed barrel. The width is wider in the rotation direction than 2b.

The lens barrel base plate 4 has an opening 4a corresponding to an aperture, and the extended portions 4b extending from the four corners are screwed to the flange 2a of the fixed barrel 2 with a screw 10 so that the flange 2a and the restricting surface. The drive ring 3 is sandwiched by 4c,
The position of the drive ring 3 in the optical axis direction with respect to the fixed barrel 2 is regulated. Further, the extension portion 4b covers the notch 3b to prevent light from the outside from entering the inside of the lens barrel. Further, the groove 4d formed adjacent to the restriction surface 4c is
It is a fitting portion of the fixed cylinder 2 with the film surface side end portion 2c, and the film both side end portions 2 whose strength is reduced by the notch 2b.
It plays the role of reinforcing c. A lens barrel unit (not shown), a fixed barrel 2, a drive ring 3, and a lens barrel base plate 4 constitute a lens barrel unit.
Since a is screwed to the mounting portion 1d of the main body 1,
It is fixed to the main body 1.

Next, in the case of a camera having trimming photographing means, a panorama switching mechanism will be taken as an example to explain the relationship between the panorama switching mechanism and the configuration of the above-described embodiment.

First, each member constituting the panorama switching mechanism will be described with reference to FIG.

Mask blades 5 and 6 are provided with aperture mask portions 5a and 6a for shielding the upper and lower portions of the aperture during panoramic photography, and each has two elongated holes 5b and 5b.
By fitting 6b into the dowel 1e of the main body 1, the main body 1 is held slidably in the vertical direction, and is provided with forked arm portions 5c and 6c extending toward the front side of the camera.

Reference numeral 7 is a first switching lever, which is rotatably held by the lens barrel base plate 4 about a shaft 7a, and a partial gear 7b about the shaft 7a is formed integrally with the upper part thereof. A second switching lever 8 is held by the lens barrel base plate 4 about the shaft 8a, and a partial gear 8b with the shaft 8a as the center of rotation is integrally formed in the lower portion and meshes with the partial gear 7b. Reference numeral 9 denotes a torgu spring, which is hung on a dowel 8d formed on the second switching lever 8 and a dowel 4e of the lens barrel base plate 4, and actuating force for applying the second switching lever 8 to both ends of the rotational drive range. To occur.

The dowel 8c of the second switching lever 8 and the dowel 7c of the first switching lever 7 are fitted to the forked arms 5c and 6c of the mask blades 5 and 6, respectively, when the lens barrel unit is attached to the main body 1. To do. At this time, the film side edges 4f of the lens barrel base plate 4 press down the aperture mask portions 5a, 6a so that the mask blades 5, 6 do not come off from the body 1, so that the mask blades 5, 6 can be moved to the body 1 and the lens barrel base plate 4. Held between and. Note that FIG. 1 shows the arrangement in the standard screen image capturing state.

Next, the switching operation from the standard screen to the panorama screen of the panorama switching mechanism having the above configuration will be described.

In conjunction with the operation of a panorama switching operation member (not shown), a pin (not shown) inserted between the two dowels 7d of the first switching lever 7 moves downward in FIG. 1 by a mechanism (not shown). Then, the dowel 7d is pushed and the first switching lever 7 is rotated counterclockwise. Then, the second switching lever 8 gear-connected to the first switching lever rotates in the clockwise direction. The counterclockwise rotation of the first switching lever 7 also causes the dowel 7c to perform an arcuate movement upward in FIG. 1 about the shaft 7a, and to move upward through the forked arm 6c of the mask blade 6 fitted with the dowel 7c. The movement of the chisel is transmitted, and the mask blade 6 moves upward. At the same time, the clockwise rotation of the second switching lever 8 also causes the dowel 8c to make an arcuate movement downward about the shaft 8a, and the mask blade 5 fitted with the dowel 8c.
The downward movement is transmitted via the bifurcated arm portion 5c, and the mask blade 5 moves downward. Mask blades 5, 6
Is carried out until it comes into contact with the stop member (in this embodiment, the elongated holes 5b and 6b and the dowel 1e of the main body 1), and the toggle spring 9 presses and holds the stop member.

By the above operation, the aperture mask portions 5a and 6a of the mask blades 5 and 6 cover the front surface of the aperture 1 up and down, and it becomes possible to take a picture on a panoramic size screen.

Switching from the panoramic screen to the standard screen is performed by following the procedure reverse to the above operation.

FIG. 2 is a vertical sectional view showing the lens barrel unit attached to the main body 1. As shown in FIG. 2, the drive ring 3 includes a flange 2 a of the fixed barrel 2 and a regulating surface 4 of the lens barrel base plate 4.
By being sandwiched by c, the position is regulated in the optical axis direction. Also, the outer diameter of the film side end portion 2c of the fixed barrel 2,
Alternatively, both the outer diameter and the inner diameter are arcuate grooves 4 of the lens barrel base plate 4.
By fitting with d, the film surface side end portion 2c is held. The mask blades 5 and 6 are held by being sandwiched between the film surface side end surface 4f of the lens barrel base plate 4 and the front surface of the aperture 1c of the main body 1.

FIG. 3 is a perspective view showing the shape of the end of the fixed barrel 2 on the film surface side.

In this figure, in this embodiment, the upper and lower end portions 2d have an outer diameter and an inner diameter, and are arcuate grooves 4d in the lens barrel base plate 4.
However, since the left and right ends 2e escape from the effective light flux, only the outer diameter fits into the groove 4d. Even if only the outer diameter is fitted, the deformation that expands to the outside can be suppressed, which is effective in preventing the helicoid from coming off.

(Second Embodiment) FIG. 4 shows a second embodiment which is a modification of the shape of the film surface side end portion of the fixed barrel 2 shown in FIG. 3 of the first embodiment. . Since the configuration other than the fixed barrel 20 is the same as that of the first embodiment, the description thereof is omitted here.

As shown in FIG. 4, this embodiment uses a fixed barrel 20.
The projection 20f is formed on the fitting portion of the end portion 20d of
On the lens barrel base plate 4, a projection 20f is provided instead of the arcuate groove 4d.
There is a hole to fit with.

Further, a projection may be formed on the lens barrel base plate 4 and a hole to be fitted thereinto may be provided at the end portion 20d.

(Third Embodiment) FIG. 5 shows a third embodiment. Since the configuration other than the fixed cylinder 30 is the same as that of the first embodiment, its illustration and description are omitted.

At the time of collapsing, the film surface side end surface of the lens barrel which collapses the inside of the fixed barrel 2 projects rearward from the film surface side end surface of the fixed barrel 2 due to a request for shortening the collapsible length due to downsizing of the camera. When the end surface 4f of the lens barrel base plate 4 approaches or almost coincides with the film surface side end face 4f, the opening 4a of the lens barrel base plate 4 must have an opening corresponding to the inner diameter of the fixed barrel 2 from the shape shown in FIG. Therefore, the groove 4d cannot hold the inner diameter of the end portion 2d of the fixed barrel 2. Therefore, as shown in FIG. 5, in the present embodiment, the inner diameter fitting portion of the end portion 30d of the fixed barrel 30 is shifted outward so that the end portion 30d has a stepped shape. By doing so, even if the opening corresponding to the inner diameter of the fixed barrel 30 is opened in the lens barrel base plate 4, the holding portion on the inner diameter side can be formed.

As described above, not only can the second and third embodiments have the same function as that of the first embodiment, but also the effect of shortening the retractable length of the lens barrel can be obtained. .

Although each of the above embodiments has been described with a camera as an example, the present invention is not limited to this and can be applied to various optical devices.

[0041]

According to the invention described in claim 1, the extending portion of the regulating means can block harmful light entering through the notches formed at the four corners of the fixed cylinder and the outer cylinder member.

In particular, when the present invention is applied to a camera as described in claim 5, the unused spaces at the four corners of the lens barrel can be effectively utilized, and the lens barrel can be miniaturized without external light leaking into the lens barrel. This makes it possible to reduce the size of the camera.

Further, by connecting the distal end of the distracted portion to the fixed cylinder,
By sandwiching the outer cylinder member with the fixed cylinder, the position of the outer cylinder member in the optical axis direction can be kept constant, and at the same time, the lens barrel can be made into a unit and can be easily attached to the main body.

According to the second aspect of the invention, since the regulating member functions as a reinforcing means for reinforcing the end portion of the fixed cylinder, the end portion of the fixed cylinder whose strength has been reduced is reinforced by the notch. When the front surface of the lens barrel is impacted, the problem that the end portion of the fixed barrel is deformed and the helicoid coupling with the inner barrel member is broken, etc. is eliminated.

According to the third aspect of the invention, the restricting means functions as a pressing means for restricting the position by pressing a light shielding member such as a mask blade for trimming.
Cost reduction and space saving can be achieved without using an extra pressing member, and when the present invention is applied to a camera, downsizing and cost reduction of the camera can be realized.

According to the invention described in claim 4, since the regulating means also functions as a holding means for holding the switching mechanism of the light shielding member on the side surface portion thereof, space saving, simplification of the die structure of the main body, Improvement of assembly workability can be achieved.

According to the fifth aspect of the present invention, it is possible to achieve space saving and cost reduction of the camera.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of the lens barrel unit of FIG. 1 attached to a main body.

FIG. 3 is a perspective view showing a shape of a film surface side end portion of a fixed barrel in the embodiment of FIG.

FIG. 4 is a perspective view of a fixed barrel showing a second embodiment.

FIG. 5 is a perspective view of a fixed barrel showing a third embodiment.

FIG. 6 is a diagram showing a relationship between a fixed barrel and an aperture.

7 is a vertical cross-sectional view of FIG. 6 showing a state where an effective light beam is blocked.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main body 2 ... Fixed cylinder 3 ... Drive ring 4 ... Lens cylinder base plate 4b ... Extension part 4d ... Arc groove 5 ... Upper side mask blade 6 ... Lower side mask blade 7 ... 1st switching lever 8 ... 2nd switching lever 9 ... Toggle spring

Claims (5)

[Claims] 1. A rectangular shape arranged rearward while transmitting a driving force to an inner cylinder member housed in a cylindrical fixed cylinder fixed to the main body by an outer cylinder member fitted to the outer periphery of the fixed cylinder. In an optical lens barrel for forming an image on a flat image forming surface, a part of each of the fixed barrel and the outer cylinder member on the image forming surface side is cut off corresponding to four diagonal corners of the image forming surface. A notch portion is formed, and a restricting portion is in contact with the end surface of the outer cylinder member on the image formation surface side, and is extended from the restricting portion toward the front so as to cover the notch portion in correspondence with the four corners in the diagonal direction. An optical barrel, wherein the outer cylinder member is sandwiched between the fixed cylinders by a restricting member having an extension portion that is coupled to the fixed cylinder. 2. The image forming surface side end of a fixed cylinder is fitted to the restriction portion of the restriction member, and a fitting portion for holding the fixed cylinder is formed. An optical lens barrel. 3. The optical barrel according to claim 1, wherein a light blocking member for changing the screen size with respect to the image formation screen is arranged between the restricting portion of the restricting member and the main body. 4. The optical barrel according to claim 3, wherein a switching mechanism for the light blocking member is attached and a holding portion is provided on a side surface of the regulating member. 5. The optical barrel according to claim 1, 2, 3 or 4, wherein the main body is a camera.