JPH09325390A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera whose cost is reduced by using a photointerruptor for the detection of a film position and a traveling speed and which restrains the depth size of the camera from increasing. SOLUTION: The photointerruptor 5 for detecting the position and the traveling speed of a film (f) has a light emitting element 5a and a light receiving element 5b opposed to each other while interposing a part where the perforation 20 of the film (f) is formed, either one of the elements 5a and 5b is arranged on a photographing lens 3 side with respect to the film (f), and is disposed so that a distance between the element 5a on the lens 3 side and the film (f) is smaller than that between the other element 5b and the film (f).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera equipped with a detector for detecting the position or running speed of a film.

[0002]

2. Description of the Related Art There is known a camera which detects a perforation by a photo reflector at the time of feeding a film and calculates the position and speed of the film based on the signal. The photo reflector has a light emitting element that emits light toward the film surface and a light receiving element that receives the reflected light, and is arranged on the side of the film taking lens or on the side opposite to the film taking lens. In a camera in which the taking lens barrel retracts into the camera body when the camera is not used, it is desirable to dispose the photo reflector on the opposite side of the film with respect to the film in order to avoid interference between the taking barrel and the photo reflector.

[0003]

By the way, it is possible to use a photointerrupter having a lower cost as a detector in place of the conventional photoreflector.
Its use is desired. However, since the photo interrupter is arranged such that the light emitting element and the light receiving element sandwich the film, it is inevitable that a part of the photo interrupter protrudes from the film surface toward the photographing lens. Therefore, in a camera in which the lens barrel can be retracted inside the camera body, there is a possibility that the lens and the photo interrupter interfere with each other when retracted, and there is a problem that the thickness of the camera becomes thicker in an attempt to avoid the interference. It was

It is an object of the present invention to provide a camera in which a photo interrupter is used to detect the position of the film, the traveling speed, etc. to reduce the cost, and the increase in the depth dimension of the camera is suppressed.

[0005]

FIG. 1 shows an embodiment of the present invention.
The present invention is applied to a camera having a film detector for detecting the position or traveling speed of the film f, and the detector faces the perforation 20 forming portion of the film f. Photo interrupter 5 having light emitting element 5a and light receiving element 5b
Either the light emitting element 5a or the light receiving element 5b is arranged on the side of the photographing lens 3 with respect to the film f, and the distance between the element 5a on the side of the photographing lens 3 and the film f is between the other element 5b and the film f. The photo interrupter 5 is arranged so as to be smaller than the distance to achieve the above object. In the camera according to the invention of claim 2, the film f has a magnetic information recording area 21, and a magnetic head 6 for performing at least one of recording and reproduction on the magnetic information recording area 21,
A pad 7 for pressing the film f against the magnetic head 6 is provided.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easier to understand. However, the present invention is not limited to the embodiment.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2 are views for explaining an embodiment of a camera according to the present invention, FIG. 1 is a sectional view of the camera, and FIG. 2 is a perspective view from the rear side of the camera (right side in FIG. 1). Reference numeral 1 is a cover for covering the camera body 2, and 3 is a photographing lens held by the lens barrel 4. Reference numeral 8 denotes a pressure plate fixed to the camera body 2, a photo interrupter 5 for detecting the feeding speed and the film position of the film f, and a magnetic head 6 for performing magnetic recording on a magnetic recording area (not shown) of the film f. Is attached.

The photo interrupter 5 has a U-shape as shown in FIG. 1. The photo interrupter 5 is a light emitting element 5a formed of a light emitting diode and a phototransistor so as to sandwich the portion of the film f which is an object to be detected in which the perforations 20 are formed. Is provided with a light receiving element 5b. In the photo interrupter 5, the upper end portion of the film f is located in the detection space 5d between the light emitting element 5a and the light receiving element 5b, and the distance between the light emitting element 5a and the film f is smaller than the distance between the light receiving element 5b and the film f. Is attached to the pressure plate 8. 6 is a magnetic information recording area 21 of the film f.
A magnetic head for magnetically recording (see FIG. 2),
Reference numeral 7 is a pad for pressing the film f against the magnetic head 6 to maintain good adhesion between the magnetic information recording area 21 and the magnetic head 6.

The subject light incident on the taking lens 3 from the left side of FIG. 1 is imaged on the film f after being shaped into a predetermined exposure range by the aperture 2a of the camera body 2. As shown in FIG. 2, the film f pulled out from the film cartridge 9 is stored in the spool 11 of the film chamber 10.
The film f is wound up by one frame by the spool 11 for each shooting. At this time, by detecting the perforation (not shown) provided on the film f by the photo interrupter 5, the shooting frame of the film f is positioned at the position of the aperture 2a. Further, since magnetic recording by the magnetic head 6 is performed while the film f is traveling, the traveling speed at the time of recording is calculated based on the signal of the photo interrupter 5, and writing or reading of recording is performed based on the speed data. .

The camera shown in FIG. 1 is a collapsible camera in which the lens barrel 4 can be retracted into the cover 1. The lens barrel 4 is on the camera side (to the right in the drawing) along the optical axis AX by a driving means (not shown). Is driven into the inside of the cover 1.
When the lens barrel 4 is retracted into the cover 1, the camera-side rear end portion of the lens barrel 4 is located near the camera body 2 as indicated by a chain double-dashed line.

Normally, the photo interrupter 5 is arranged so that the film surface and the center position 5c of the photo interrupter 5 are aligned with each other, but in the present embodiment, the center position 5c is displaced from the film surface toward the rear side of the camera. ing. Therefore, the rear end position when the lens barrel 4 is collapsed can be brought closer to the film f, and the dimension from the film f to the front end of the camera can be reduced. on the other hand,
Since a space such as a magnetic head is originally provided in the space on the back side of the film f, it is not necessary to increase the size from the film f to the rear end of the camera even if the photo interrupter 5 is shifted to the back side. That is, even if an inexpensive photointerrupter is used instead of the conventional photoreflector, the thickness of the camera does not increase.

Although the magnetic head 6 is used for recording in the magnetic information recording area 21 in the above-described embodiment, it may be configured so that at least one of recording and reproduction can be performed.

[0013]

As described above, according to the present invention,
A relatively inexpensive photo interrupter is used as a detector to detect the position or running speed of the film, and the distance between the film lens element of the photo interrupter and the film is set smaller than the distance between the other element and the film. Therefore, the cost of the camera can be reduced and the thickness of the camera does not increase.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a first embodiment of a camera according to the present invention.

FIG. 2 is a rear perspective view of the camera shown in FIG.

[Explanation of symbols]

 1 Cover 2 Camera Body 3 Photographic Lens 4 Lens Barrel 5 Photointerrupter 5a Light Emitting Element 5b Light Receiving Element 6 Magnetic Head 7 Pad 20 Perforation 21 Magnetic Information Recording Area f Film

Front page continuation (72) Inventor Minoru Kato 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Inside Nikon Corporation

Claims (2)

[Claims] 1. A camera having a film detector for detecting the position or traveling speed of a film, wherein the detector comprises a photo interrupter having a light emitting element and a light receiving element facing each other with a perforation forming portion of the film sandwiched therebetween. Either the light emitting element or the light receiving element is arranged on the photographing lens side with respect to the film, and the distance between the photographing lens side element and the film is smaller than the distance between the other element and the film. A camera comprising the photo interrupter. 2. The camera according to claim 1, wherein the film has a magnetic information recording area, and a magnetic head for performing at least one of recording and reproducing of information in the magnetic information recording area, and the film. A camera provided with a pad for pressing the magnetic head.