JPH06175206A - Light shielding structure for camera - Google Patents

Abstract

PURPOSE:To effectively block unnecessary light passing through the photographic lens of a camera and reaching a film by providing a spool chamber light shielding member in a spool chamber. CONSTITUTION:A fixing part 31a for a supporting member is provided in the vicinity of a position where a spool chamber wall surface 41C crosses a film feeding path wall surface 51a between upper and lower rail surfaces. The supporting member is fixed on the spool chamber light shielding member 11. It serves as a cantilever member as well, a supporting end part 11a is fixed on a restraining member and a free end part 11b is projected into the spool chamber 41b, so that a pencil of light rays B passing through the photographic lens 42 from an object and reaching the aperture of the side of the spool chamber 41b is prevented from being reflected on the rear of the film and entering the spool chamber 41b, that is, the straying of light is prevented. On the other hand, on a housing part 43, a light shielding member with an aperture diaphragm 21 having an aperture diaphragm 21a for a pencil of light rays finished to pass through the photographic lens 42 and an inner surface reflection preventing wall 21b is provided. The inner surface reflection preventing wall 21b eliminates the stray light, back light, etc., of a pencil of light rays finished to pass through the photographic lens 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding structure for a camera, and more particularly to light-shielding a bundle of rays passing through a taking lens.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional example of shielding a bundle of rays that passes through a photographing lens of a camera. Description will be made with reference to FIG.

(1) An aperture is provided as a light-shielding structure for preventing the light flux from leaving the subject, passing through the taking lens 705 of the camera substrate 701 and reaching the film surface, and being reflected by the film surface, and preventing the light from going around the film in the spool chamber 706. It is known to keep the spool chamber away from the side end of the film, or to reduce the distance between the film and the wall surface 7 of the spool chamber light shielding member between the upper rail surface and the lower rail surface of the film.

(2) It is also known that the aperture stop 702 for limiting the image plane illuminance of the light that has exited the subject and passed through the taking lens is made of a thin flat metal part.

Further, the inner surface antireflection wall 704 is provided with the aperture stop 7
There is one different from 02.

[0006]

The conventional light-shielding structure for a camera has the following problems.

(1) Because of the stray light that enters the spool chamber, the light flux that has passed through the taking lens and has a distance between the aperture end on the spool chamber side and the wall surface of the spool chamber on the aperture end side is mainly reflected by the film surface. , It can't be shortened, so it is difficult to downsize the camera.

If the gap between the film and the wall of the spool chamber light shielding member between the upper rail surface and the lower rail surface is narrowed to reduce unnecessary light, the surface of the film contacts the wall surface of the spool chamber light shielding member. The film may be scratched.

(2) Since the thin flat plate aperture stop member is located at the back of the housing, it is difficult to mount it, and the parts are thin and easily deformed during mounting.

An object of the present invention is to obtain a light-shielding structure that effectively shields unnecessary light passing through a photographing lens of a camera and reaching a film. In claims 1 and 2, the side surface of the aperture is further provided on the wall surface of the spool chamber. The aim is to make the camera smaller due to the narrow gap between the and.

It is an object of the present invention to limit the light amount of the image plane illuminance of the light flux passing through the taking lens, prevent stray light and back light, and simplify the attachment of the light shield member with the aperture stop by a simple light shield structure. .

[0012]

Such an object is achieved by the present invention described below.

That is, (1) a spool chamber and a film feed path are provided on the camera base, and a support member is provided near the intersection of the wall surface of the spool room and the wall surface between the upper and lower rail surfaces of the film feed path, A light-shielding structure for a camera, characterized in that a spool chamber light-shielding member having a support end fixed by a support member and a free end in the spool chamber is provided to prevent stray light from entering the spool chamber through a photographing lens. .

(2) A part of the light blocking member with an aperture stop having a substantially truncated pyramidal shape having an aperture stop for the light flux passing through the taking lens and an inner surface antireflection wall forms a support member for fixing the spool chamber light blocking member. The light-shielding structure of the camera according to item 1.

(3) A support member is provided on the housing of the camera base in the space between the taking lens and the film feeding path, and the aperture stop and the internal reflection preventing wall of the light flux fixed by the supporting member and passing through the taking lens. A light blocking member with an aperture stop having a substantially square pyramid shape is provided, and the light amount of the image plane illuminance is limited by the aperture stop and stray light and back light are prevented by the inner surface antireflection wall, and the light blocking member with an aperture stop is attached. A light-shielding structure for the camera, characterized by its simplicity.

[0016]

The present invention will be described in detail below with reference to Examples 1 to 3 shown in the drawings.

(Embodiment 1) Embodiment 1 will be described with reference to FIGS.

FIG. 1 is a perspective view of a rear surface of a camera to which the present invention is applied, FIG. 2 is a view showing a cross section taken along line AA of FIG. 1, and FIG.
FIG. 4 is an exploded perspective view of each component, and FIG. 5 is an explanatory view of a method of fixing the light blocking member with the aperture stop.

The first embodiment is a lens-equipped film camera in which the film F is wound around a spool in advance and is wound up on a cartridge P each time a picture is taken.

Reference numeral 41 denotes a camera base, which has a spool chamber 41b for accommodating a film wound around the camera base 41, a patrone chamber 45 for accommodating a film cartridge which winds up the film on a film cartridge P each time a picture is taken, and a photographing lens 42. Film feeding path 51 and shooting lens 42 for feeding the film
A housing portion 43 between the film feeding path 51 and the film feeding path 51 is provided.

Further, the spool chamber wall surface 41c and the upper rail surface 52
A fixing portion 31a of a support member (not shown) is provided in the vicinity of the intersection of a with the film feed path wall surface 51a between the lower rail surfaces 52b. The support member fixes a spool chamber light shielding member 11 described later.

The spool chamber light shielding member 11 is a cantilever member, the support end 11a is fixed to the locking member, and the free end 11b projects into the spool chamber 41b. A bundle of rays B reaching the aperture 44 on the spool chamber side through the lens is reflected by the film surface and is reflected in the spool chamber.
Prevent stray light entering 41b.

On the other hand, a housing portion 43 is provided on the camera base 41 in the space between the taking lens 42 and the film feeding path 51.
The support member 32 is provided on the housing portion 43. Further, the housing portion 43 is provided with an aperture stop 21a for the light flux that has passed through the taking lens 42 and a light blocking member 21 with an aperture stop having an internal reflection preventing wall 21b.

Incidentally, a part of the supporting member fixing portion 31a of the light shielding member 21 with the aperture stop is a supporting end portion of the spool chamber light shielding member 11 described above.
Supports 11a.

The projection 31b of the support member 32 is fitted into the hole 21c of the light-shielding member 21 with the aperture stop and fixed by caulking. In order to secure the fixing, for example, the protrusion outer diameter 31d
It is desirable that the protrusion 31c is 1.2 mm and the protrusion 31c of the protrusion is 0.5 mm (see FIG. 5).

The light blocking function of the spool chamber light blocking member 11 will be described.

A bundle of rays of light that has left the subject, passes through the taking lens 42, and reaches the vicinity of the aperture 44 on the spool chamber 41b side is reflected by the film and tries to enter the spool chamber 41b.

Next, the function of the light blocking member with the aperture stop will be described.

The aperture stop 21a exits the subject and the photographing lens 42
The light quantity of the image plane illuminance of the bundle of rays passing through is limited. The aperture stop shape is a pincushion shape in order to prevent a decrease in the amount of peripheral light.

The inner surface anti-reflection wall 21b prevents stray light and back light of the light flux that has passed through the taking lens.

(Embodiment 2) FIG. 6 shows a modification of the light blocking member 21 with an aperture stop according to the present invention.

The light shielding member 22 with an aperture stop of this embodiment is different from the first embodiment mainly in that the supporting member 32 and the light shielding member 21 with an aperture stop are fixed by caulking in the first embodiment.
In the second embodiment, the elasticity of the support member 32 and the plastic is used to fix it by the locking claws 22d provided on the light-shielding member 21 with the aperture stop.

The present embodiment has the effect that it is easier to mount than the first embodiment. A spool chamber light-shielding member is integrated at one end on the spool chamber side.

(Embodiment 3) FIG. 7 shows a modification of the spool chamber light shielding member 11 of the present invention.

The main difference between the spool chamber light-shielding member 12 having the support end 12a and the free end 12b of this embodiment from that of the first embodiment is that in the first embodiment, the support member 32 is replaced with the light-shielding member 21 with an aperture stop.
In the third embodiment, it is fixed to the wall surface of the spool chamber (not shown).

[0036]

Since the present invention is constructed as described above, the following effects can be obtained.

In the light-shielding structure of the camera of the first aspect, (1) since the spool-room light-shielding member 11 is provided in the spool chamber 416, the light flux leaving the subject and passing through the photographing lens to the vicinity of the aperture on the spool-room side is a film. It is possible to prevent the light from reflecting on the surface and entering the spool chamber side, and to prevent unnecessary light on the film.

(2) Since the distance between the end of the aperture 44 on the spool chamber side and the wall surface of the spool chamber on the aperture end side can be shortened, the camera can be downsized.

In the light-shielding structure for a camera according to claim 2,
In addition to the effect of claim 1, since the spool chamber light shielding member and the spool chamber light shielding member in the housing portion of the camera base are integrated, the structure is simplified and the mounting is simplified.

In the light-shielding structure for a camera according to claim 3,
Since the aperture stop and the inner surface antireflection wall behind the photographing lens of the camera are formed into a substantially truncated pyramid shape, the light quantity of the image plane illuminance can be limited, stray light and back light can be prevented, and the attachment can be performed by a simpler work.

[Brief description of drawings]

FIG. 1 is a perspective view of a back surface of a camera to which the present invention is applied.

2 is a first embodiment of the present invention showing a sectional view taken along the line AA of FIG.

3 is a first embodiment of the present invention showing a cross-sectional view taken along the line BB of FIG.

FIG. 4 is an exploded perspective view of each component according to the first embodiment of the present invention.

FIG. 5 is a fixing explanatory view of a light blocking member with an aperture stop in Embodiment 1 of the present invention.

FIG. 6 is a perspective view of a light blocking member with an aperture stop according to a second embodiment.

FIG. 7 is a perspective view of a spool chamber light shielding member according to a third embodiment.

FIG. 8 is a schematic explanatory diagram of a light shielding structure of a conventional camera.

[Explanation of symbols]

 11 Spool chamber light-shielding member 11a Spool chamber light-shielding member support end 11b Spool chamber light-shielding member free end 21,22 Aperture stop light-shielding member 21a Aperture stop 21b Inner surface anti-reflection wall 31,32 Support member 31a Support member fixing part 31b Projection 41 Camera base 41b Spool chamber 41c Spool chamber wall 42 Photographing lens 43 Housing 51 Film feeding path 51a Film feeding path wall F Film P Patrone

Claims (3)

[Claims] 1. A camera body is provided with a spool chamber and a film feed path, and a support member is provided near a wall surface of the spool chamber with a wall surface between upper and lower rail surfaces of the film feed path.
A spool chamber light-shielding member having a support end fixed by the support member and a free end in the spool chamber is provided to prevent stray light from entering the spool chamber through a photographing lens. Construction. 2. A part of a light blocking member with an aperture stop of a substantially truncated pyramid shape having an aperture stop for a light beam passing through a taking lens and an inner surface antireflection wall forms a support member for fixing the spool chamber light blocking member. The light shielding structure for a camera according to claim 1. 3. A support member is provided in a housing portion of a space between a taking lens and a film feeding path on a camera base, and an aperture stop for a bundle of rays passing through the taking lens and an internal reflection preventing wall fixed by the supporting member. By providing a light blocking member with an aperture stop having a substantially quadrangular pyramid shape, the light amount of the image plane illuminance is limited by the aperture stop, stray light and back light are prevented by the inner surface antireflection wall, and the light blocking member with an aperture stop is easily attached. The light-shielding structure of the camera characterized in that