JPH1039385A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera which can be efficiently focused, at a low cost. SOLUTION: A cam ring 29 on which a cam surface 71 helically inclined along a photographic optical axis is formed is freely rotatably held between the light shielding barrel 27 of a camera main body 23 and a lens barrel unit 28 and the projection pieces 36b of the lens barrel unit 28 are abutted on the cam surface 71. Then, the cam ring 29 is rotated to move the lens barrel unit 28 along the photographic optical axis to attain focusing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera whose focus is adjusted during manufacturing.

[0002]

2. Description of the Related Art In a camera, the focus of a photographing lens is adjusted at the time of manufacture. As a method, a distance between a plurality of lenses constituting the photographing lens is changed, or a lens barrel in which the photographing lens is incorporated. Is moved along the photographing optical axis so that the photographing lens is focused at infinity. In addition, the focus adjustment method for moving the lens barrel is performed by adjusting the thickness of a washer inserted between the lens barrel and the camera body.

[0003]

However, in the above-mentioned focus adjusting method, an appropriate washer is inserted between the camera body and the lens barrel, the lens barrel is temporarily fixed to the camera body, and then the focus inspection is performed. If they did not match, the lens barrel was removed again and another washer was sandwiched in between, which was very inefficient. In addition, as a method of adjusting the focus efficiently,
There is a helicoid method, etc., but this requires a large space around the taking lens, which increases the size of the camera, and further increases the number of parts and the processing accuracy of each part, thus increasing costs. There is also the problem of a significant rise.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a camera capable of performing focus adjustment efficiently at low cost.

[0005]

In order to solve the above-mentioned problems, a camera according to the present invention has a cam surface which is spirally inclined along a photographing optical axis between a light shielding tube and a lens barrel. The cam ring thus formed is rotatably held therebetween, and the lens ring is moved along the photographing optical axis by rotating the cam ring around the photographing optical axis to perform focus adjustment.

[0006]

FIG. 2 shows the appearance of an instant camera embodying the present invention. The instant camera 2 has a structure in which a film loading chamber is formed, and the outside of a camera body 23 (see FIG. 1) to which various photographing mechanisms and the like are assembled is covered with a front cover 24 and a rear cover 25 as exterior members from front and rear. It has become.

An opening 3 is provided on the front of the instant camera 2.
A lens barrel 4 having a photographing lens incorporated therein and a strobe light emitting section 5 are provided at the back of the camera. On one side, a grip 6 used at the time of photographing is integrally formed, and a shutter button 7 is provided on an upper portion thereof. On the other side, a finder 8 for confirming the photographing range is provided, and on the upper surface, a discharge port 10 for discharging the photographed film unit 9 is provided.

Although not shown, a film loading chamber for loading a film pack containing a plurality of film units 9 is provided inside the instant camera 2, and the film loading chamber is opened and closed on the rear side. A back cover is provided.

The instant camera 2 uses a two-point zone focus system, and uses a zone switching ring 12 rotatably provided on the lens barrel 4 for switching the focus zone. A concave index 13 is provided on the outer peripheral surface of the zone switching ring 12, and the index 13 is marked on the upper surface of the lens barrel 4 with marks 19 and 2.
The focus zone is switched by adjusting to 0 and 21. The marks 19 and 20 represent a near view and a distant view, and when the index 13 of the zone switching ring 12 is aligned with the mark 19, the photographing lens in the lens barrel 4 is moved to a position where a short-distance subject is in focus. When the camera is set to, the taking lens moves to a position where a subject at a long distance is focused.

The zone switching ring 12 also serves as a power switch of the instant camera 2,
1 indicates a power-off position. When the index 13 of the zone switching ring 12 is set to the mark 19 or the mark 20, the power is turned on, and when the index 13 is set to the mark 21, the power is turned off. On the front surface of the lens barrel 4, a photometric window 16, a light receiving window 17, and an arc-shaped slit 14 are provided. From the slit 14, an operation knob 15 for switching the density control is projected. I have.

As shown in FIGS. 1 and 3, the lens barrel 4 is
A light-shielding tube 27 formed on the front side of the camera body 23; a lens-barrel unit 28 which is a lens barrel mounted on the front surface of the light-shielding tube 27;
7 and a protection cylinder 30 formed integrally with the front cover 24 so as to cover them.
A zone switching ring 12 rotatably mounted on the outer periphery of the protection cylinder 30;
Protection ring 31 assembled to protection cylinder 30 in front of 2
Consists of The light-shielding cylinder 27 shields light from the photographing opening 27a provided on the front surface to the photographing surface of the film unit 9 in the film loading chamber.

As shown in FIG. 4, the lens barrel unit 28
A shutter unit 34 in which a photographing lens including a front lens 32 and a rear lens 33 is built in front and back, and this shutter unit 34 is built in, and a switch board 35 is mounted on the front surface and fixed to the front surface of the light shielding tube 27. A fixed cylinder 36 and a cam cylinder 38 rotatably mounted on the outer periphery of the fixed cylinder 36 and having a metal contact 37 attached to a front edge thereof.

The shutter unit 34 has an electronic shutter incorporated in an annular unit main body 40, and a front lens 32 and a rear lens 33 are respectively accommodated in holding cylinders 40a formed before and after the unit main body 40. The annular lens holders 42a and 42b are attached before and after the lens holder. The outer peripheral surface of the unit body 40 has
The cam pins 43 are erected at regular intervals.

An opening 36a for allowing subject light to enter the photographing lens is formed on the front surface of the fixed cylinder 36.
It is screwed to the front surface of the light shielding tube 27 using three protruding pieces 36b formed at equal intervals on the rear side. Three slits 47 are formed on the outer peripheral surface of the fixed cylinder 36 at positions corresponding to the cam pins 43 of the shutter unit 34 along the optical axis direction. The cam pins 43 of the shutter knit 34 are inserted into these slits 47, respectively, and hold the shutter unit 34 movably along the optical axis direction in the fixed cylinder 36.

On both sides of the opening 36a of the fixed cylinder 36, built-in holes 36c and 36d into which a photometric CdS element 49 and a phototransistor 50 used for controlling an auto strobe are respectively formed are formed. 49 and the phototransistor 50 perform photometry through the photometry window 16 and the light reception window 17 on the front surface of the lens barrel 4.

In front of the CdS element 49 and the phototransistor 50, inside the protective tube 30 of the front cover 24, the detection sensitivity of the CdS element 49 and the phototransistor 50 is changed to perform density control. A disk-shaped filter plate 51 (see FIG. 3) is rotatably incorporated. The operation knob 1 described above is provided on the filter plate 51.
5 are integrally formed.

On the front surface of the fixed cylinder 36, a switch board 35
A substrate mounting surface 53 is formed on the rear side where the board is screwed down. The switch substrate 35 is formed of a flexible substrate, and has a plurality of contact portions used for turning on / off the power of the instant camera 2 and detecting the rotational position of the zone switching ring 12. The above-mentioned CdS element 49 is attached to a portion indicated by reference numeral 35a, and a portion extended to the rear side indicated by reference numeral 35b is connected to a control circuit for controlling the entire instant camera 2.

Three cam grooves 55 into which the cam pins 43 of the shutter unit 34 are inserted are formed on the inner diameter surface of the cam cylinder 38. When the cam cylinder 38 is rotated clockwise in FIG. 1, these cam grooves 55
The shutter unit 34 is moved forward along the optical axis direction using the and the slit 47 so as to focus on a distant subject. Conversely, when the cam barrel 38 is rotated in the counterclockwise direction, the shutter unit 34 is moved rearward along the optical axis direction to focus on a nearby subject.

When the shutter unit 34 is in the distant view position, the subject from, for example, about 2.5 m to infinity is focused, and the subject at a distance of 3.26 m is most appropriately focused. . When the shutter unit 34 is in the close-up position, the subject at a distance of about 50 cm to about 3 m is in focus.
It is designed to best focus on a subject at a distance of 9 m.

On the outer peripheral surface of the cam cylinder 38, two engaging portions 57a and 57b formed of two ridges are formed in a rotationally symmetric manner. A protruding piece 58 (see FIG. 3) protruding from the inner diameter surface of the second member is engaged. Thus, the cam cylinder 38 rotates integrally with the rotation of the zone switching ring 12. The protruding piece 58 of the zone switching ring 12 passes through the notch 59 formed in the protection cylinder 30 of the front cover 24, and engages with the engagement portions 57a, 5a.
7b. The notch 59 is formed such that the protruding piece 58 does not interfere with the protection cylinder 30 in the rotation range of the zone switching ring 12.

The metal contact piece 37 is formed of a thin metal plate, and is screwed to the front end of the cam barrel 38. The metal contact piece 37 has three contact pieces 60, 6 having elasticity.
Reference numerals 1 and 62 are provided, each of which is slightly bent toward the rear side so that a tip portion contacts a contact portion of the switch board 35.

A hole 67 is formed in the cam barrel 38, and a small-diameter iron ball 68 is accommodated in the hole 67. When the zone switching ring 12 coincides with each of the marks 19 to 21, the ball 68 enters a concave portion (not shown) formed on the outer peripheral surface of the fixed cylinder 36, and the ball 68 clicks on the rotating operation of the zone switching ring 12. give.
The strip 69 integrally formed with the metal contact piece 37 is
The spring is attached to the outer peripheral surface of the cam barrel 38 at a position corresponding to the hole 67 to prevent the ball 68 from falling out of the hole 67 and to press the ball 68 against the outer peripheral surface of the fixed barrel 36.

As shown in FIG. 1, a cam ring 29 sandwiched between the lens barrel unit 28 and the light-shielding cylinder 27 has an annular shape, and a first outer peripheral surface of the light-shielding cylinder 27 is utilized by utilizing an inner diameter portion 29a. Attached to 70. On the front side of the cam ring 29 facing the lens barrel unit 28, three cam surfaces 71 corresponding to the three projecting pieces 36b of the fixed barrel 36 and contacting the projecting pieces 36b are formed. This cam surface 71
Is formed from the operation part 72 used when rotating the cam ring 29 to the operation part 72 of the adjacent cam surface 71 so as to gradually head toward the light shielding cylinder 27 along the photographing optical axis. It has a spiral spiral inclination.

The rear surface 74 of the cam ring 29 facing the light shielding cylinder 27 is a flat surface. The rear surface 74 is in contact with a guide surface 75 of the light shielding tube 27 which is also a flat surface. Also,
On each cam surface of the cam ring 29, a slit 76 that penetrates the cam ring 29 along the photographing optical axis is formed. A screw 77 that penetrates the protruding piece 36b of the fixed cylinder 36 is inserted into these slits 76, and the slit 76
Are screwed into screw holes 78 formed in the guide surface of the light shielding cylinder 27, respectively.

A tooth row 80 is partially formed on the first outer peripheral surface of the light-shielding cylinder 27. The cam ring 29 has an inner diameter portion 29a which meshes with the tooth row 80 to prevent the cam ring 29 from rotating. An engaging portion 81 is formed. The meshing portion 81 is hollowed out and is provided with elasticity so that the meshing portion 81 is securely meshed with the tooth row 80. However, when the cam ring 29 is rotated with a strong force, the meshing portion 81 bends. The cam ring 29 can be rotated.

Next, the operation of the above embodiment will be described. In the manufacture of the instant camera 2, the camera body 23
At the point when the other components than the front cover 24 and the rear cover 25 are almost assembled, the lens barrel unit 28 is assembled and the focus of the photographing lens is adjusted.

As shown in FIG. 1, the inner diameter portion 29a of the cam ring 29 is fitted into the first outer peripheral surface 70 of the light shielding cylinder 27.
Next, the lens barrel unit 28 is connected to the camera body 23 by inserting the second outer peripheral surface 83 of the light-shielding barrel 27 into the fixed barrel 36.
Attach to When attaching the lens barrel unit 28, the projecting piece 36b of the fixed barrel 36 is screwed into the screw hole 8 of the light shielding barrel 27.
2 and a screw 77 from the front side of the protruding piece 36b.
Is inserted, and the tip of the screw 77 is screwed into the screw hole 82 through the slit 76 of the cam ring 29.

The screw 77 is screwed into the screw hole 82 so that the lens barrel unit 28 can be slightly moved along the photographing optical axis. Also, the cam barrel 38 is rotated clockwise in FIG. 1 to set the camera body 23 on the collimator with the shutter unit 34 set on the distant view side, and to perform a focus inspection of the photographing lens.

If the image is out of focus, the operation unit 72
And rotate the cam ring 29 in either direction. In this case, the lens barrel unit 28 is connected to the camera body 2.
3 so that the protruding piece 36b comes into contact with the cam surface 71 of the cam ring 29. When the cam ring 29 is rotated, a portion of the cam surface 71 abutting on the protruding piece 36b
Since the distance of the light-shielding cylinder 27 from the guide surface 75 changes, the fixed cylinder 36 slightly moves in the photographing optical axis direction in accordance with the change.

When the adjustment of the cam ring 29 and the focus inspection as described above are performed and the focus is achieved, the screw 77
To securely attach the lens barrel unit 28 to the light-shielding cylinder 27. Even if the cam ring 29 is rotated, the meshing portion 81 is always meshed with the tooth row 80 of the light shielding cylinder 27, so that the rotational position does not shift when the screw 77 is tightened.

After the focus adjustment is completed, the camera body 23 is assembled with the front cover 24, the rear cover 25, etc., and is completed as the instant camera 2, and is sold after various functional tests.

In the above embodiment, the instant camera has been described as an example. However, the present invention can also be applied to a camera using a 110, 135, 120 film or a camera using a 24 mm size film.

[0033]

As described above, a cam ring having a cam surface spirally inclined along the photographing optical axis is rotatably sandwiched between the light shielding tube and the lens barrel, and the cam ring is photographed. By rotating around the optical axis, the lens barrel is moved along the photographing optical axis to perform focus adjustment, so that focusing can be performed easily and quickly. Also, the only additional component is the cam ring, and the other components need only be slightly changed in shape, so that they can be adopted at low cost. In addition, the size of the camera is not affected because the area around the taking lens is not increased.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a lens barrel.

FIG. 2 is a perspective view illustrating an appearance of an instant camera embodying the present invention.

FIG. 3 is a cross-sectional view of a main part showing a state of a lens barrel during close-up photography.

FIG. 4 is an exploded perspective view showing a configuration of a lens barrel unit.

[Explanation of symbols]

 2 Instant Camera 4 Lens Barrel 12 Zone Switching Ring 13 Index 19-20 Mark 27 Shade Barrel 28 Barrel Unit 29 Cam Ring

Claims (1)

[Claims] 1. A camera in which a lens barrel holding a photographing lens is mounted on a front surface of a light-shielding tube for light-tightly shielding from a photographing opening formed on a front surface to a film disposed behind the light-shielding tube. A cam ring having a cam surface that is spirally inclined along the photographing optical axis is rotatably sandwiched between the cylinder and the lens barrel, and the cam ring is rotated around the photographing optical axis to thereby rotate the lens mirror. A camera wherein focus adjustment is performed by moving a cylinder along a photographing optical axis.