JPH05150285A - Film information detection device for camera - Google Patents

Abstract

PURPOSE:To save the space of a film information detection device and to contribute to the miniaturization of a camera. CONSTITUTION:Movable contact pieces 31-33 obtained by fixing code detection pins 27a-27c on the tips thereof and a movable contact piece 34 obtained by fixing a using state display detection pin 28 on the tip thereof are fixed to the back wall of a cartridge loading chamber by one fixing member 35. Besides, a common contact piece 37 with which the pieces 31-34 are respectively brought into contact under a state before the pieces 31-34 are displaced is fixed to the back wall. Thus, a reference voltage is given to the respective pieces 31-34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film information detecting device for a camera which detects film information such as film sensitivity from a DX code provided on the surface of a photographic film cartridge.

[0002]

2. Description of the Related Art In recent years, as described in U.S. Pat. No. 4,834,306 or Japanese Patent Application Laid-Open No. 3-37645 by the present applicant, a method of feeding the leading end of a photographic film from a discharge port of a cartridge body by spool rotation. A photo film patrone of is proposed. Since such a photographic film cartridge has a complicated internal structure,
The molded plastic body is used as the cartridge body. It has been proposed that this plastic cartridge body be provided with a DX code that encodes film information such as film sensitivity and latitude. This DX code is formed in an uneven shape by taking advantage of the characteristics of plastic.

As a camera-side film information detecting device for detecting such a concave-convex DX code, microswitches of a number corresponding to the number of bits of the DX code are used, and each microswitch is turned ON and OFF. It is known to detect film information.

[0004]

However, the film information detecting device as described above requires a large space for mounting a plurality of microswitches in the camera, so that a camera incorporating the microswitch tends to be large in size. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a film information detecting apparatus which can contribute to downsizing of a camera by achieving space saving.

[0006]

In order to achieve the above object, the film information detecting device for a camera according to claim 1 of the present invention projects into a loading chamber into which a photographic film cartridge is loaded, and when loading the cartridge. The movable contact pieces that are displaced by contact with the information display section provided on the outer wall of the cartridge body and the movable contact pieces that are not displaced when the cartridge is not loaded are in contact or non-contact with each other. It sometimes comprises a fixed contact piece for applying a reference voltage to each of the movable contact pieces. Further, in the film information detecting device for a camera described in claim 2, in the invention of claim 1, each end of the movable contact piece on the side opposite to the side in contact with the information display portion is fixed by one fixing member. It was done.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, a photographic film cartridge 2 used in a camera according to the present invention comprises a cartridge main body 3 composed of a resin-molded upper case 3a and a lower case 3b, and a cartridge main body. 3 includes a spool 4 rotatably housed therein, and a photographic film (not shown) which is wound around the spool 4 with its rear end fixed and is housed up to the leading end before and after photographing. Upper and lower cases 3a, 3
The inside of b has a structure in which the photographic film is not unraveled inside the cartridge body 3, and the photographic film is sent out from the film entrance / exit 5 by the rotation of the spool 4. A circular hole 7 and an elliptical hole 8 that determine the radial position of the photographic film cartridge 2 are formed on the side surface 6 where the end 4a of the spool 4 is exposed.

A DX code display section 10 and a usage status display section 11 are provided adjacent to each other on the outer wall of the lower case 3b. The DX code display unit 10 transmits the film sensitivity to the camera side depending on the number and position of the cuts 10a. The usage status display section 11 displays the use / unuse of the photo film cartridge 2 depending on the position of the display plate 11a, and is slid by a mechanism on the camera side immediately before taking out the photo film cartridge 2 and taking it out. Display that it has been completed.

As shown in FIG. 3, the camera 19 using the present invention is provided with a cartridge loading chamber 20 for receiving the cartridge main body 3. A fork 21 that engages with and drives the end 4a of the spool 4 is provided in the back of the cartridge loading chamber 20. Around this fork 21,
A pop-up spring 22 for pushing back the used photo film cartridge 2 is provided, and two positioning pins 23 which are fitted in the holes 7 and 8 to prevent the cartridge main body 2 from rotating around the spool are provided in the vicinity of the pop-up spring 22. , 24
Is provided. The reference numeral 25 is a bottom lid that closes the cartridge loading port 26 of the cartridge loading chamber 20 in a light-tight manner.

In the vicinity of the cartridge loading port 26 of the cartridge loading chamber 20, code detecting pins 27a to 27c for detecting the DX code 10 and a usage status display detecting pin 28 for detecting the usage status display section 11 are formed in the side wall 20a. It projects toward the inside of the cartridge loading chamber 20 via. As shown in FIG. 1, the cord detection pins 27a to 27c and the usage status display detection pin 28 are fixed to the tips of the conductive movable contact pieces 31, 32, 33, 34 having a spring property, respectively, and are set in the cartridge loading chamber. It is biased toward the inside of 20.

The tip ends of the code detecting pins 27a to 27c are spherical, and when the photographic film cartridge 2 is put in or taken out of the cartridge loading chamber 20, the code detecting pins 27a are arranged along the slope 10b of the DX code display portion 10. ~ 2
7c can be moved. Further, the tip of the use status display detection pin 28 is formed in a tapered shape as shown in the figure, and when the unused photo film cartridge 2 is inserted into the cartridge loading chamber 20, the usage status display section 11
The tip of the use status display detection pin 28 falls into the groove 11b, and the photo film cartridge 2 is locked at the loading position. When the photo film cartridge 2 is used and the display board 11a is moved, the usage status display detection pin 28 is pushed away, the photo film cartridge 2 is unlocked, and the photo film cartridge 2 can be taken out. ..

Code detection pin 27 of the movable contact pieces 31-34
The end portion on the opposite side of the tip to which the a to 27c and the usage status display detection pin 28 are fixed is fixed to the back wall 36 of the cartridge loading chamber 20 by one fixing member 35. Then, the common contact piece 37 is provided on the back wall 36 with the movable contact piece 31.
It is fixed in the direction orthogonal to 34. This comm
The on contact piece 37 is a common contact piece that gives a reference voltage to the movable contact pieces 31 to 34, and when the photographic film cartridge 2 is not loaded in the cartridge loading chamber 20, the movable contact pieces 31 to 34 are always in contact with each other. is doing.

A decoder 40 is connected to the movable contact pieces 31 to 34, and the decoder 40 has movable contact pieces 31 to 34c.
When the contact with the ommon contact piece 37 is "0", and when it is apart, it is "1". After the film sensitivity and the use / non-use are discriminated from this combination, this discrimination signal controls various controls of the camera 19. Output to a microcomputer.

The operation of the above structure will be described below. Camera 1 with photo film cartridge 2 unloaded
In FIG. 9, the movable contact pieces 31 to 34 are always in contact with the common contact piece 37. For example, when the main switch is turned on in conjunction with an operation such as opening the barrier of the taking lens, the potentials of the movable contact pieces 31 to 34 become the same as the reference potential of the common contact piece 37.

On the other hand, when the photographic film cartridge 2 is not used, the photographic film is wound up to the leading end in the cartridge body 3 and the display plate 11a is in the position shown in FIG. When this photographic film cartridge 2 is loaded into the camera 19, it is inserted into the cartridge loading chamber 20 with the side surface 6 having the holes 7 and 8 facing upward. When the photo film cartridge 2 is fully inserted, the fork 21 engages with the end 4a of the spool 4 and the positioning pins 23 and 24 are fitted into the holes 7 and 8 so that the photo film cartridge 2 is set at the correct loading position. To be done. At this time, hole 8
Has an oval shape, so even if there is a relative error between the positions of the holes 7 and 8 on the side of the photo film cartridge and the positions of the positioning pins 23 and 24 on the side of the camera, it is within a slight range. If so, it can be absorbed.

At the same time, the use status display detection pin 28
While reaching the groove 11b of the usage status display section 11 while being guided by the inclined surface 10b, the code detection pins 27a to
27c reaches a predetermined detection position on the DX code display unit 10. Since the display board 11a is not in the position where the usage status display detection pin 28 abuts, the usage status display detection pin 28
The tip of the groove enters the groove 11b. As a result, the photographic film cartridge 2 is locked in the cartridge loading chamber 20 and the movable contact piece 34 remains in contact with the common contact piece 37, so that the photographic film cartridge 2 loaded by the decoder 40 is in an unused state. Is recognized. Further, among the code detection pins 27a to 27c, only the code detection pin 27b enters the notch 10a, and the other code detection pins 27a and 27c contact the top 10c of the DX code display unit 10, so that the movable contact piece 3 is formed.
1, 33 are separated from the common contact piece 37, and the movable contact piece 3
Only two remain in contact. As a result, the decoder 40 changes the code represented by the DX code display unit 10 to "101".
And film sensitivity corresponding to this, for example, ISO
400 is output to the microcomputer.

When the photographic film cartridge 2 is inserted into the cartridge loading chamber 20 and the bottom lid 25 is closed, the cartridge loading chamber 20 is light-tightly closed. When it is confirmed that the bottom lid 25 is locked at the closed position, the film feeding mechanism built in the camera 19 operates and the fork 21 is driven in the film feeding direction.

When all the photographing is completed, the photographic film is rewound inside the cartridge main body 3 and then automatically stopped. When the bottom lid 25 is opened, the display plate 11a is operated by the member provided on the camera 19 in conjunction with the opening operation, that is, the position indicating that the display plate 11a has been used, that is, the usage status display detection pin
Is slid to the position of the groove 11b which is in contact with.
Since the use status display detection pin 28 is pushed away by the display plate 11a and is disengaged from the groove 11b, the photo film cartridge 2 is unlocked and moved to the cartridge loading port 26 side by the pop-up spring 22. As a result, the photographic film cartridge 2 can be easily taken out.

When the used photo film cartridge 2 is loaded by mistake, the usage status detecting pin 28 contacts the display plate 11a and the movable contact piece 34 separates from the common contact piece 37. The fact that the film cartridge 2 has been used is output to the microcomputer. The microcomputer displays a warning to the user and prevents the shooting sequence such as the feeding of the photo film from being executed. Further, since the usage status display detection pin 28 does not enter the groove 11b, the photographic film cartridge 2 is not locked in the cartridge loading chamber 20,
The pop-up spring 22 pushes back to the cartridge loading port 26 side. In this way, the photo film patrone 2
Is not stored in the cartridge loading chamber 20,
The user can know that the photo film cartridge 2 has been used.

In the embodiment described above, the movable contact piece contacts the common contact piece when the photographic film cartridge is not loaded in the cartridge loading chamber. It may be arranged at a position opposite to the embodiment, and the photographic film cartridge may be loaded in the cartridge loading chamber so that each movable contact piece comes into contact with the common contact piece when each movable contact piece is displaced. Further, although three movable contact pieces are used to detect the DX code and one movable contact piece is used to detect the use status, the present invention is not limited to this, and for example, two movable contact pieces are provided to detect the use status, and “used”. In addition, "in use" may be detected. Also, D
The number of movable contacts for X-code detection may be increased so that the number of shots, latitude, negative / positive determination, etc. can be detected in addition to the film sensitivity.

[0021]

As described above in detail, in the film information detecting apparatus for a camera of the present invention, the fixed contact piece that comes into contact with the movable contact piece and gives the reference voltage is also used, so that the number of parts is reduced. Since the wiring is simplified and the device is downsized, the device can be installed in the camera in a small space, which contributes to downsizing of the camera. Further, if a plurality of movable contact pieces are fixed by one fixing member, the number of parts can be further reduced, which can contribute to downsizing of the camera.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing the relationship between a movable contact piece, a common contact piece, and a fixed member according to the present invention.

FIG. 2 is a perspective view of the outer appearance of the photographic film cartridge as seen from the side of the cartridge loading chamber where the fork is engaged.

FIG. 3 is a partial cutaway view schematically showing the internal structure of a cartridge loading chamber formed in the camera of the present invention.

[Explanation of symbols]

 2 Photo film Patrone 3 Patrone body 4 Spool 10 DX code display section 11 Usage status display section 19 Camera 21 Patrone loading chamber 27 Code detection pin 28 Usage status detection detection pin 31, 32, 33, 34 Movable contact piece 35 Fixed member 37 common Contact piece

Claims (2)

[Claims] 1. A film information detecting device for a camera using a photo film cartridge in which an information display section for displaying film information such as film sensitivity by unevenness is provided on the outer wall of the film cartridge main body, in a loading chamber in which the photo film cartridge is loaded. When the patrone is loaded, the plurality of movable contact pieces that are displaced by contact with the display portion when the patrone is loaded and the movable contact pieces that are not displaced when the patrone is not loaded are in contact or non-contact with each other. A film information detecting device for a camera, comprising: a fixed contact for applying a reference voltage to each of the movable contacts. 2. The film information detecting device for a camera according to claim 1, wherein each end of the movable contact piece on the side opposite to the side in contact with the information display section is fixed by one fixing member. ..