JP3224331B2 - Manufacturing method of camera shading chamber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a camera light-shielding chamber in which a member for effectively diffusing and attenuating internal reflected light is formed on an inner wall surface of a camera light-shielding chamber integrally formed of resin. It is.

[0002]

2. Description of the Related Art A light-shielding chamber provided in a camera allows only light passing through a lens to reach a film surface and blocks other light. This is manufactured by injecting a resin in a flowing state into a combination of a concave mold forming the outer wall of the light-shielding chamber and a convex mold forming the inner wall of the light-shielding chamber. Then, when taking a picture, a stair-like ridge was formed on the convex mold to prevent the flare generated when the light obliquely entering the taking lens reflected the inner wall surface and reached the film surface. A step-like ridge is integrally formed on the inner wall surface of the light shielding room. As a result, light obliquely entering the photographing lens is repeatedly reflected / diffused between the ridges and attenuated. However, in this case, if particularly strong light such as sunlight at daylight enters, a sufficient diffusion effect cannot be obtained, and flare occurs.

It is also conceivable to use a convex mold having a large number of small holes formed on the surface of the above-mentioned step-shaped ridge, and to form a large number of textures for diffusing the internally reflected light on the surface of the ridge. However, in this case, there is a problem that the surface of the grain is shaved when the mold on the convex side is extracted, and whitening and abrasion are likely to occur. Therefore, as in the case of a general camera, a flocked paper is attached to the wall surface of the light shielding room.

[0004]

However, when flocked paper is stuck to the wall surface of the light-shielding chamber, a considerably high flare preventing effect can be obtained, but it takes time and effort to stick the flocked paper, resulting in an increase in cost. . In addition, it is not suitable to use a product in which recycling characteristics are important, such as a film unit with a lens, because different materials are mixed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing a camera light-shielding room in which flare is effectively suppressed at low cost.

[0006]

According to a first aspect of the present invention, there is provided a method for manufacturing a light-shielding chamber for a camera, wherein the taper gradually expands from an opening on a photographic lens side toward an opening on a film side. A resin-made camera light-shielding chamber with an inner wall surface is provided, and the jig having a plurality of step-shaped ridges is pressed against the inner wall surface of the camera light-shielding chamber and heated. The jig is pushed in while melting the jig abutting part on the inner wall surface of the shading chamber, and the melted resin rises in the gap between the inner wall surface of the camera shading chamber and the step-shaped ridge of the jig. The internal reflection light diffusion ridge is used.

According to a second aspect of the present invention, there is provided a method for manufacturing a light-shielding chamber for a camera, comprising a tapered inner wall surface which gradually expands from an opening on a photographic lens side toward an opening on a film side, and the inner wall surface has a step-like shape. A resin camera light-shielding chamber in which a plurality of ridges are integrally formed is provided, and the stair-like protrusion of the jig in which a plurality of step-like ridges are formed in the camera light-shielding chamber is pressed against the protrusion of the camera light-shielding chamber. Heat it and push in the jig while melting the jig abutment part on the inner wall surface of the camera light shielding room,
The melted resin is raised in the gap between the inner wall surface of the camera light-shielding chamber and the step-shaped ridge of the jig, and the raised portion is used as an internally reflected light diffusion ridge.

According to a third aspect of the present invention, in the method for manufacturing a camera light-shielding chamber according to the first or second aspect, the melting of the jig contact portion of the camera light-shielding chamber is performed by using an ultrasonic wave. This is performed by vibration.

[0009]

FIG. 4 is an exploded perspective view showing a unit body of a film unit with a lens according to the present invention. The unit main body is composed of a front cover 3, a main body 4, an exposure unit 5, a photographic film 7 and a patrone 8, and a rear cover 9, and the front cover 3, the main body 4, the exposure unit 5, and the rear cover 9 have recycling characteristics. In view of this, resin molded products are mainly used.

A box-shaped light-shielding chamber 13 is formed at the center of the main body 4. An exposure unit 5 incorporating a photographic lens 16 and a film winding mechanism is attached to an exposure opening 14 opened in the front of the light shielding chamber 13. After the exposure unit 5 is mounted, the front cover 3 integrally formed with the release button is mounted on the front surface of the main body 4, and the patrone 8 and the patrone 8 are formed in the patrone storage chamber 19 and the film roll chamber 20 formed on both sides of the light shielding chamber 13. Photo film 7
Are stored in the rear cover 9 in a light-tight manner.

As shown in FIG. 1, the light-shielding chamber 13 has a tapered inner wall surface which gradually expands from the exposure opening 14 toward the film surface. The processing device 25 that processes the light-shielding chamber 13 includes a processing jig 26, a pushing portion 27 to which the processing jig 26 is assembled, and a holding portion 24 that holds the main body 4 when processing the light-shielding chamber 13. Have been. The pushing portion 27 is vertically moved by a hydraulic cylinder (not shown), and an ultrasonic head 28 is built in a mounting portion of the processing jig 26. When the processing head 26 is pressed against the inner wall surface of the light shielding chamber 13 by the pressing portion 29, the ultrasonic head 28 ultrasonically vibrates in a direction along the contact surface, and generates frictional heat at the contact portion.

As shown in FIG. 2A, a plurality of step-like ridges 22 are integrally formed on the inner wall surface of the light shielding chamber 13. The ridge 22 has an orthogonal surface 22a orthogonal to the optical axis of the light-shielding chamber.
And a horizontal plane 22b parallel to the optical axis. The outer surface of the processing jig 26 is in contact with the surface 22a,
A plurality of step-like protrusions 23 having a gap 26c with the protrusion 2b are integrally formed with the protrusions 22 of the light shielding chamber 13 at the same pitch.

Next, the operation of the above embodiment will be described. As shown in FIG. 1, the main body portion 4 is obtained by pouring a resin in a flowing state into an injection molding die and taking it out after a lapse of a predetermined time, and reversely rotating a film roll chamber 20, a patrone storage chamber 19, a light shielding chamber 13, and a winding knob. The prevention claw and the like are integrally formed. At this time, a plurality of step-like projections 22 are integrally formed on the inner wall surface of the light shielding chamber 13.

When the main body 4 is set on the holder 24,
The pushing portion 27 is lowered, the processing jig 26 is pushed into the light shielding chamber 13, and the step-like ridge 23 is pressed against the orthogonal surface 22a as shown in FIG. Next, the contact surface is rubbed by the ultrasonic vibration, and the ridge 22 is melted by the frictional heat. Since the processing jig 26 is pushed into the light shielding chamber 13 while dissolving the ridge 22, the softened portion rises in the gap 26c as shown in FIG. 2 (B), and the internally reflected light diffusion ridge 30 is formed. . Since the internally reflected light diffusion ridge 30 is formed by swelling the softened resin, the surface is rough and the light diffusion property is improved.

Next, the pushing portion 27 is raised, and the processing jig 26 is separated from the light shielding chamber 13. Internal reflection light diffusion ridge 30
Is formed in the gap 26c, so that when the processing jig 26 is pulled out, the surface of the internally reflected light diffusing ridge 30 is not shaved and no whitening or scratches occur.

An exposure unit 5 is assembled to the main body 4 having the light-shielding chamber 13 formed with the internally-reflected light diffusion ridges 30 in an assembly line of a film unit with a lens. The patrone storage room 19 and the film roll room 2
At 0, a photo film 7 and a patrone 8 are stored. Further, the front cover 3 and the rear cover 9 are attached, and the assembly of the unit main body is completed. Thereafter, the paper box is put on the unit main body.

When taking a picture with the film unit with a lens, the photographer first turns the winding knob to wind the film. In conjunction with this film winding,
When the shutter is charged and the film for one frame is wound up, the winding stop mechanism operates to lock the winding. Thereafter, framing is performed by looking through the viewfinder, and by pressing the release button, the shutter blades are driven to open and close to perform photographing.

When the shutter blades are opened and closed, the subject light passes through the photographing lens and the exposure aperture, and forms an image on a photographic film. At this time, as shown in FIG. 2C, intense light, for example, sunlight at daytime or illumination light from the ceiling may enter the inner wall surface of the light shielding room 13 through the taking lens as shown in FIG. Most of the light is diffused and attenuated by the internally reflected light diffusion ridges 30, and therefore hardly reaches the photographic film. Therefore, the occurrence of flare is suppressed, and a good image is obtained.

Further, instead of the light-shielding chamber 13 having the projections 22 formed on the inner wall, the light-shielding chamber 41 may have a flat inner wall 44 as shown in FIG. 3A. In this case, the processing jig 42 on which the step-shaped ridge 43 is formed is pressed against the inner wall surface 44 of the light-shielding chamber, and the ridge 4 is formed in the same manner as described above.
Processing jig 4 while melting the contact portion 3 by ultrasonic vibration
Press 2. As shown in FIG. 3B, the melted portion rises in a gap 45 between the inner wall surface 44 and the ridge 43 to form an inner surface reflected light diffusion ridge 50. As shown in FIG. 3C, the subject light is diffused and attenuated and absorbed by the curved surface of the internally reflected light diffusion ridge 50. The same components as those in the above embodiment are denoted by the same reference numerals.

The pressing step of the processing jig in each of the above embodiments may be two-thirds or less of the horizontal plane of the ridge of the processing jig. In this case, the diffusion and reflection of the subject light can be effectively prevented. An internal reflection preventing diffusion portion having a height that can be achieved is formed.

In each of the above-described embodiments, the step-like inner surface reflected light diffusion ridge is formed on the entire inner peripheral surface of the light shielding chamber. However, it may be formed only on the surface where the flare becomes stronger. Alternatively, a heating device such as a heater may be used as the processing jig, and the heated processing jig may be pressed against the light-shielding chamber to process the inner-surface reflected light diffusing portion. In addition, the step-shaped ridge of the processing jig is set to a pitch different from that of the step formed on the inner wall surface of the light-shielding chamber. It may be formed. Further, when a processing jig 52 having a plurality of tapered surfaces formed on each step surface as shown in FIG. 5 is used as the processing jig, an internally-reflected light diffusion ridge having a higher light diffusion efficiency can be obtained. Can be formed.

In the above embodiment, the case where the light-shielding chamber of the lens-fitted film unit is manufactured has been described. However, the present invention may be applied to the case where a light-shielding chamber of a general camera or the like is manufactured.

[0023]

According to the present invention, the jig is pressed against the wall surface of the light-shielding chamber, and is pressed while melting the wall surface of the light-shielding chamber, so that the melted portion rises in the gap between the wall surface of the light-shielding chamber and the jig. The internally reflected light diffusion ridge is easily formed. Therefore, it is possible to manufacture a light-shielding room that can effectively prevent flare caused by strong light from a light source without increasing costs. In addition, there is no need to use another material such as flocking, and the suitability for recycling is improved.

In the method for manufacturing a camera light-shielding chamber according to the first or second aspect, since the jig contact portion of the camera light-shielding chamber is melted by ultrasonic vibration, fine irregularities are formed on the molten raised surface. Thus, the diffusivity of the internally reflected light can be further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an apparatus for forming an internally reflected light preventing ridge in a light shielding chamber.

FIGS. 2A and 2B are enlarged cross-sectional views showing a main part of a state in which an internally reflected light diffusion ridge is formed on a wall surface on which a ridge is formed in a stepped shape; FIG. 4 is an explanatory diagram showing the diffusivity by the internally reflected light diffusion ridge.

FIGS. 3A and 3B are enlarged cross-sectional views showing a main part of a state in which an internally reflected light diffusion ridge is formed on a wall formed by a plane, and FIG. It is explanatory drawing which shows the diffusivity by a light-diffusion ridge.

FIG. 4 is an exploded perspective view of the film unit with a lens.

FIG. 5 is a perspective view showing a part of another processing jig.

[Description of Signs] 13 Light-shielding chamber 22 Protrusion 22a Orthogonal surface 22b Horizontal surface 23,43 Step-like protrusion 25 Processing device 26,42 Processing jig 26c, 45 Gap 28 Ultrasonic head 30,50 Inner surface reflected light diffusion protrusion

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 17/02 G03B 17/04 G03C 3/00 575

Claims (3)

(57) [Claims] 1. A resin camera light-shielding chamber having a tapered inner wall surface which gradually expands from an opening on the taking lens side toward an opening on the film side is provided, and a plurality of step-like projections are formed. The jig is pressed against the inner wall of the camera light-shielding chamber and heated, and the jig is pushed in while melting the jig abutting part of the inner wall of the camera light-shielding chamber. A method for manufacturing a light-shielding chamber for a camera, wherein the raised part is raised in a gap between an inner wall surface of a light-shielding chamber and a step-shaped ridge of a jig, and the raised part is an inner-surface reflected light diffusion ridge. 2. A resin camera having a tapered inner wall surface which gradually expands from an opening on the taking lens side toward an opening on the film side, and a plurality of ridges integrally formed on the inner wall surface in a stepwise manner. A step-shaped projection of a jig having a plurality of step-shaped projections formed in the camera light-shielding chamber is pressed against the projection of the camera light-shielding chamber and heated, and the inner wall surface of the camera light-shielding chamber is heated. The jig is pushed in while melting the jig abutting part, and the melted resin rises in the gap between the inner wall surface of the camera light-shielding chamber and the stair-like ridge of the jig. A method for manufacturing a light shielding room for a camera, comprising: 3. The method of manufacturing a camera light-shielding chamber according to claim 1, wherein the jig contact portion of the camera light-shielding chamber is melted by ultrasonic vibration. Method.