JP2763217B2 - Sprocket mounting structure for film unit with lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film unit with a lens.

[0002]

2. Description of the Related Art A film unit with a built-in photo film and a lens having a simple photographing function (for example, a product name " It is H
i ") is commercially available by the applicant. Since the film unit with a lens needs to be provided at a price that is not so different from the purchase of a normal color film, the entire structure is simple. In addition, a structure that allows automatic assembly as much as possible is adopted so that mass production is possible.

In this film unit with a lens, the film is wound up by rotating a knob, and the film transfer force at this time is converted into a rotational force by a sprocket engaging with the perforation to charge the shutter of the shutter mechanism. Like that. When a film having a length of one frame is fed, the rotation of the sprocket is regulated by the shutter mechanism, whereby an unexposed film is set on the exposure frame.

[0004]

The above-mentioned sprocket has the following features.
In the film transfer path of the unit main body, it is arranged in the sprocket receiving recess at a position corresponding to the perforation. A square hole is formed in the sprocket, and the tip of the sprocket shaft associated with the shutter mechanism is fitted in the shaft hole. When assembling this sprocket with the sprocket shaft,
First, after loading the sprocket into the storage recess, insert the sprocket shaft from the bearing of the unit body, align the sprocket shaft with the shaft hole of the sprocket, and fit the tip of the sprocket shaft into the shaft hole. I have. Since the shaft hole of the sprocket is formed of a square hole so that the sprocket shaft does not run idle, there is a problem that it is difficult to perform positioning for inserting the sprocket shaft into the shaft hole. In particular, since it is necessary to align the two with the sprocket placed in the storage recess, the shaft hole cannot be visually confirmed, and the work must be performed while groping. There is a problem that efficiency is reduced. In addition, since it is necessary to align the two, there is a problem in performing the automatic assembly, and there is a problem that the sprocket cannot be efficiently incorporated into the unit body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a sprocket mounting structure for a film unit with a lens, which allows a sprocket shaft to be easily inserted into a shaft hole of the sprocket. I do.

[0006]

In order to achieve the above object, according to the present invention, a circular projection for positioning is formed concentrically with a shaft hole on an end face of a sprocket, and a sprocket receiving recess is formed in the sprocket receiving recess. When the sprocket is inserted into the recess, a guide groove is formed at a position corresponding to the circular protrusion to receive the protrusion, and the guide groove has a circular protrusion concentric with the shaft hole of the storage recess. A semicircular positioning groove having substantially the same diameter is provided.

[0007]

FIG. 2 shows a film unit with a lens (hereinafter simply referred to as a film unit) embodying the present invention. The film unit 2 is composed of a unit main body 3 having a photographing mechanism and an outer case 4 for housing the same. Photographing is performed while the film unit 2 is kept in the outer case 4. The outer case 4 is for making the appearance of the film unit 2 beautiful, and uses a paper box having an outer surface printed thereon. The outer case 4 includes a photographing lens 5, an object-side finder window 6a, an eyepiece-side finder window 6b, a shutter button 7, a number-of-photographs display plate 8, a winding knob 9,
Further, a hole for exposing the strobe light emitting unit 10 is provided. Although the outer case 4 described above is a paper box,
It may be a plastic sheet or the like.

FIG. 3 shows the unit main body 3. The unit main body 3 includes a main body 20, a front cover 21, and a rear cover 22. On the front surface of the main body 20, a shutter unit 25 in which the photographing lens 5 is arranged is provided.
And a strobe unit 26 that holds the light emitting unit 10. A patrone chamber, an exposure chamber and a film chamber (not shown) are formed on the back side of the main body 20 from the left side in the figure, and the film 23 with the patrone is loaded on the back side of the main body 20. In this state, the rear cover 22 is detachably attached to the main body 20 by a claw. After the photographing is completed, a bottom cover 59 for taking out the patrone containing the film is provided on the rear cover 22 so as to be freely opened and closed. Also, the film transfer path 60 has a film 2
A sprocket escape recess 61 is formed at a position where the third perforation 23a passes.

In FIG. 4 showing the shutter unit 25, a shutter unit base 2 having an exposure opening 28 is shown.
9, a positioning hole 39 for positioning when this is attached to the main body 20, and claw receiving portions 40 a and 40 b are integrally formed on both sides of the exposure opening 28. The shutter unit base 29 has a plastic shutter blade 32 urged counterclockwise by a spring 36.
A shutter cover 37 for holding the taking lens 5 is attached to the shutter unit base 29 so that the shutter blades 32 do not fall off.

On the upper portion of the shutter unit base 29, shafts 40c and 40d and a bearing 40e are formed. A shaft number 40c is provided with a number-of-images display plate 8 and a shutter drive cam 31 having a shutter drive lever 31a formed thereon. Have been. This locking lever 30 normally engages with a shutter driving lever 31a urged in a counterclockwise direction by a spring 35 to prevent the rotation of the shutter driving cam 31, and when the shutter button 7 is pressed, The engagement with the shutter drive lever 31 is released. When the engagement with the locking lever 30 is released, the shutter driving lever 31a is rotated counterclockwise by the spring 35, and the arc-shaped pressing surface 31b formed on the shutter driving lever 31a is brought into contact with the claw of the shutter blade 32. Press the portion 32a.

A sprocket shaft 49 serving as a shaft of the cam 33 engaged with the locking lever 30 is inserted through the bearing 40e. The driven sprocket 34, which is turned counterclockwise when the film is wound, is fitted on the shaft 49.
9a. In the driven sprocket 34, positioning disks 50 are formed concentrically with the shaft holes 51 so as to protrude from both end surfaces thereof.

As shown in FIG. 1, the driven sprocket 34
Is inserted into a sprocket receiving recess 53 recessed on the back side of the shutter base 29. Sprocket storage recess 53
Is composed of an arc-shaped groove having an inner diameter slightly larger than the outer diameter of the sprocket 34. The sprocket receiving recess 53 is provided with the driven sprocket 3 inside the recess 53.
4, the teeth 34 a of the sprocket 34 slightly protrude from the film transfer path 60 (see FIG. 3), and are formed to a depth that engages with the perforations 23 a of the film 23 passing through the film transfer path 60. I have. When the sprocket 34 is inserted into the storage recess 53, the positioning disk 50 is
Guide groove 5 into which positioning disk 50 enters at a position corresponding to
5 are provided. A semicircular positioning groove 57 having the same diameter as the disk 50 and being concentric with the shaft hole 56 is provided at the innermost portion of the guide groove 55. The edge 53a of the storage recess 53 has an inclined surface that gradually opens as going outward, and the sprocket 34 to the storage recess 53 is formed.
Can be easily inserted.

Therefore, when the film winding knob 9 is turned to wind the film, the sprocket 3 is rotated.
4 rotates counterclockwise, whereby the cam 33 also rotates counterclockwise, and the shutter drive lever 31a returns to the initial position via the cam arm 31c formed on the shutter drive cam 31, and The number-of-photographs display plate 8 rotates by one division.

Next, the sprocket 34 is inserted into the storage recess 5.
3 and the tip fitting portion 4 of the sprocket shaft portion 49
An assembling operation of inserting the 9a into the shaft hole 51 of the sprocket 34 will be described. First, as shown in FIG. 1, the sprocket 34 is inserted into the storage recess 53. In this insertion, the inclined surface 53a serves as a guide, so that the sprocket 34 can be easily inserted into the concave portion 53. In the recess 53, the disc 50 is positioned by the positioning groove 57, so that the shaft hole 56 of the bearing 40 e of the shutter base 29 and the shaft hole 51 of the sprocket 34 match. In this state, the sprocket shaft 49 is inserted into the shaft hole 56.
Is inserted and the sprocket 34 is rotated. When the tip fitting portion 49a of the sprocket shaft 49 and the shaft hole 51 of the sprocket 34 match, the tip fitting portion 49a
Easy to insert.

The operation of the thus-configured film unit with lens will be described. When the shutter button 7 is pressed, the locking lever 30 is pressed in conjunction with this. As a result, the locking lever 30 is moved, and the shutter driving lever 31 that has been disengaged by this movement is moved.
a is rotated counterclockwise from the initial position by a spring 35. The pressing surface 31b engages with the claw portion 32a and presses the claw portion 32a to instantaneously rotate the shutter blade 32. As a result, the claw 32a is pressed rightward, so that the shutter blade 32 is rotated clockwise, and the exposure opening 28 is opened. Thereafter, when the shutter blade 32 is further rotated clockwise, the engagement of the pressing surface 32b with the claw portion 32a is released. When the engagement is released, the shutter blade 32 is rotated counterclockwise by a spring 36, and the exposure aperture 2 is rotated.
8 is returned to the closing position, and the photographing ends. The shutter drive lever 31a is connected to the cam arm 31c by the cam 33.
, The rotation is stopped.

After the photographing is completed, the winding knob 9 is turned,
When the film 23 is wound around the cartridge, the driven sprocket 34 is rotated counterclockwise through the perforations 23a. Accordingly, the cam 33 rotates counterclockwise against the bias of the spring 35, and rotates the shutter drive lever 31a clockwise. During this rotation, when the shutter drive lever 31a comes into contact with the claw portion 32a, it is deformed upward and gets over it. Then, when the shutter drive lever 31a returns to the initial position and the shutter is charged, the preparation for the next photographing is completed.

In the above embodiment, the sprocket 34
Although the positioning discs 50 are provided on both end faces of the recording medium, this may be only one end face. In addition, the positioning disk 50
Instead, an annular ridge may be provided to form the positioning projection.

[0018]

As described above, according to the present invention,
A positioning protrusion is provided on the end surface of the sprocket, and a guide groove for guiding the positioning protrusion to the shaft hole is provided in the recess for accommodating the sprocket. Can be positioned to match. Therefore, it is not necessary to insert the sprocket shaft into the shaft hole of the sprocket in a groping state as in the related art, and the sprocket shaft can be easily inserted into the sprocket. In addition, since the centers of both shaft holes can be aligned by simply inserting the sprocket into the storage recess, automatic assembly is also possible.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a sprocket mounting structure of the present invention.

FIG. 2 is a perspective view showing an appearance of a film unit with a lens.

FIG. 3 is an exploded perspective view showing a unit main body.

FIG. 4 is an exploded perspective view showing a shutter unit.

[Description of Signs] 7 Shutter button 25 Shutter unit 34 Sprocket 49 Sprocket shaft 50 Positioning disk 51 Shaft hole 53 Sprocket storage recess 55 Guide groove 57 Positioning groove

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-156234 (JP, A) JP-A-3-237454 (JP, A) JP-A-4-234023 (JP, A) 74228 (JP, U) Fully open 1987-118223 (JP, U) Fully open 1988-115134 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03B 17/00 G03C 3 / 00

Claims (1)

(57) [Claims] 1. A sprocket for engaging with the perforation of a film and rotating to regulate the film feed and charge the shutter, and a sprocket inserted into a shaft hole of the sprocket and storing the sprocket in a storage recess of the film transfer path. In a film unit with a lens having a sprocket shaft rotatably mounted, a circular projection for positioning is formed on the end face of the sprocket concentrically with the shaft hole, and the sprocket receiving recess is provided in the sprocket receiving recess. When inserting a circular projection, a guide groove is formed at a position corresponding to the circular projection, into which the projection enters, and the guide groove has a diameter substantially the same as that of the circular projection concentric with the shaft hole of the storage recess. A sprocket mounting structure for a film unit with a lens, wherein a semicircular positioning groove is provided.