JP2002333662A - Method for positioning light receiving element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily position a light receiving element. SOLUTION: An auto strobe substrate 28 is temporally secured at a strobe substrate 28 and the auto strobe substrate 28 is roughly positioned. The inner wall surface of a front cover 11 is provided with a positioning pin 1a. The auto strobe substrate 28 is provided with a positioning hole 28b. When the front cover 11 is assembled, the positioning 11a is fitted into the positioning hole 28b and the position of the light receiving element 35 is determined. An elastic body 38 is disposed between the auto strobe substrate 28 and the strobe substrate 26. The auto strobe substrate 28 can be thrust with sufficient thrusting force to the strobe substrate 26 and mispositioning is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for positioning a light receiving element mounted on a circuit board of a camera.

[0002]

2. Description of the Related Art Auto strobes are widely used in various cameras such as compact cameras and instant cameras. As is well known, an auto strobe receives a strobe light emitted from a strobe light emitting unit and reflected by a subject by a light receiving element, and stops the irradiation of the strobe light when the amount of received light reaches an optimum amount.

On the other hand, a light receiving element used for an auto strobe in a low-cost camera is fixed to a circuit board by soldering to a circuit pattern surface. This circuit board is incorporated between a main body base provided with a photographic lens, a film storage room, and the like, and an exterior cover that covers the exterior. A light receiving window is provided on the exterior cover, and the light receiving element is exposed to the outside from the light receiving window, and external light enters the light receiving element through the light receiving window.

[0004]

As a simple camera, there is known a film unit with a lens in which an unexposed photographic film is pre-loaded. Some of the film units with a lens have various functions depending on the application. In particular, a film unit with a built-in flash device is widely used so that photographing can be performed even at night or in a dark room.

By the way, when an auto strobe is provided in a conventional film unit with a built-in strobe lens,
It is necessary to newly adopt a strobe device having an auto strobe function instead of the conventional one. For this reason, if an auto strobe is provided in a conventional film unit with a built-in strobe and a lens, the conventional strobe device becomes unnecessary and must be discarded. However, since the film unit with the lens is manufactured on the premise of recycling, it is not preferable to dispose of the conventional flash device in consideration of the manufacturing cost and the effect on the environment.

Therefore, in order to provide an automatic strobe in a conventional film unit with a lens, it is advantageous to add an auto strobe board having an automatic strobe circuit to the conventional film unit with a lens. In this case, in consideration of a built-in space or the like, the auto strobe substrate is disposed on the front surface of the conventional strobe substrate, and the light receiving element is provided on the auto strobe substrate. Then, by connecting the terminals of the circuit elements mounted on the conventional flash substrate to the auto flash substrate, it becomes possible to add an auto flash function to the conventional flash device.

However, in order to add an auto strobe board to a conventional film unit with a lens, unless the auto strobe board is positioned at a predetermined position, the relative position between the light receiving element and the light receiving window is shifted, and proper photometry is performed. May not be possible. In this case, if the auto strobe substrate is attached using a jig or a tool such as soldering or screwing, the work process becomes complicated, thereby increasing the manufacturing cost.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to make it possible to easily position a light receiving element with respect to a light receiving window through which a part of external light enters the light receiving element. .

[0009]

In order to achieve the above object, a method for positioning a light receiving element according to the present invention comprises a strobe light between a main body base in which a photographing mechanism is incorporated and a front cover for covering a front surface of the main body base. A main substrate on which a light emitting portion is held, a circuit pattern is formed, and a circuit element is mounted is disposed, and a light receiving element for measuring external light through a light receiving window formed in a front cover is provided on the front surface of the main substrate and the front side. In a method for positioning a light receiving element of a camera mounted on a front surface of a sub-substrate disposed between the cover and a cover, a positioning pin protruding toward the main substrate is provided on an inner wall of the front cover, and a positioning hole is formed in the sub-substrate. Then, the positioning pins are fitted into positioning holes of the sub-board by assembling the front cover to the base of the main body. And performs eye.

An elastic body is provided between the back surface of the sub-board and the front surface of the main board. The sub-board is temporarily fixed to the front face of the main board together with the elastic body, and the sub-board is attached by assembling the front cover. It is preferable to be sandwiched between the front cover and the main board via an elastic body. Further, the main substrate includes:
Circuit components constituting a main strobe circuit including a discharge tube, a main capacitor, a charging circuit and a trigger circuit are mounted, and the sub-substrate is provided with a discharge tube based on an integrated light amount of strobe reflected light measured by the light receiving element. It is preferable that a circuit component constituting a strobe dimming circuit for stopping light emission is mounted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a film unit with a lens 10 is covered with a front cover 11 and a rear cover 12 constituting an exterior cover. A viewfinder 13, a photographing lens 14, a strobe light emitting unit 15, a strobe charging member 16, a light receiving window 17, and a shutter button 18, a film counter 19, and a charging completion display member 20 are provided on the top of the lens-fitted film unit 10.
And a part of the hoisting knob 21 is exposed from the back.

As shown in FIGS. 2 and 3, a flash device 25 is provided inside the film unit 10 with a lens. The strobe device 25 includes a strobe substrate 26 as a main substrate, a strobe light emitting section 15, a power supply battery 27, and an auto-strobe substrate 28 as a sub-board.
The strobe light emitting unit 15 is attached to a strobe substrate 26, and includes a strobe discharge tube, a reflector, and the like. The strobe board 26 is disposed between the main body base 29 in which the photographing mechanism is incorporated and the front cover 11.
A circuit pattern is formed on the front side of the strobe board 26, and circuit components such as a main capacitor 30, a synchro switch 31, and a step-up coil are mounted on the back side to form a main strobe circuit. Sync switch 31
Is turned on when the shutter button 18 is pressed.

The auto flash substrate 28 is a flash substrate 2
6 and a front cover 11 to form a strobe light control circuit. A terminal 30a of the main capacitor 30 and a terminal 31a of the sync switch 31 protrude from the front side of the strobe board 26.
The strobe light control circuit is added to the conventional strobe circuit formed on the strobe substrate 26 by joining the 9a and 30a to the auto strobe substrate 28 by soldering or the like.

A photometric device 34 is provided on the front surface of the auto strobe board 28. The photometric device 34 includes the light receiving element 3
5, a light receiving element case 36 and a protector 37. The light receiving element 35 has a light receiving surface 35a formed on the front surface and a connection terminal 35b protruding downward. The connection terminal 35b is bent from the middle toward the auto strobe board 28, and its end is connected to the circuit pattern of the auto strobe board 28 by soldering. In this embodiment, a phototransistor is used as the light receiving element 35.

The light receiving element case 36 is provided with a fitting claw 36a, and the fitting claw 36a is attached to the auto strobe board 28 so that the light receiving element case 3
6 is attached to the auto flash substrate 28. The light receiving element 35 is housed in the light receiving element case 36, and a light receiving surface 35a of the light receiving element 35 is exposed to the outside through an opening formed on one side surface. The protector 37 is made of a transparent plastic, and is attached to the front surface of the light receiving element case 36. Note that the protector 37 may have a function as a condenser lens for condensing the subject light.

A pair of locking claws 28a are provided on the side surface of the auto strobe board 28. The locking claw 28a is used for temporarily fixing the auto flash substrate 28 to the flash substrate 26 when assembling the film unit 10 with a lens. The locking claw 28a is formed in the flash substrate 26.
To lock.

A positioning hole 28b is provided below the photometric device 34 on the auto strobe board 28. Also,
Positioning pins 11a are integrally formed on the inner wall surface of the front cover 11, and the positioning pins 11a protrude toward the auto strobe board 28. Positioning pin 11
a has a tapered end portion, and this tapered portion is fitted into the positioning hole 28b. In addition, positioning pin 1
1a has a tapered tip, and positioning holes 2
8b is easy to fit.

Strobe board 26 and auto strobe board 2
An elastic body 38 is provided between the elastic member 38 and the elastic member 38. Elastic body 38
Is made of an insulating material and has a strobe substrate 2
6 and the auto strobe board 28 are elastically deformed. As a result, the auto flash substrate 28 is positioned on the positioning pin 11.
a is pressed against the strobe substrate 26 with a sufficient pressing force,
The position does not shift. The elastic body 3
It is preferable to use, for example, maltoprene as 8, and other suitable members can be used.

As shown in FIG. 4, the main strobe circuit 42 of the strobe device 25 includes a charging circuit 43, a trigger circuit 44,
It comprises a strobe discharge tube 45, a main capacitor 30, a power supply battery 27 and the like. The charging circuit 43 is provided with a strobe switch 46.
6 is slid to the ON position, the strobe switch 4
6 turns on. In the charging circuit 43, the strobe switch 4
When the switch 6 is turned on, the voltage of the power supply battery 27 is boosted to charge the main capacitor 30, and when the shutter button 18 is pressed and the synchro switch 31 is turned on, the electric charge charged in the main capacitor 30 is strobed. Tube 4
5 to emit light.

The strobe light control circuit 47 includes a light receiving element 35,
It is composed of an integrating capacitor 48, a thyristor 49 and the like. In the strobe light control circuit 47, the strobe discharge tube 45
At the same time, the light reflected from the subject is received by the light receiving element 35, and the obtained photoelectric current is integrated by the integrating capacitor 48. Then, when the integration amount reaches a predetermined level, the thyristor 49 is operated to stop the discharge of the main capacitor 30 in the strobe discharge tube 45 and stop the light emission of the strobe discharge tube 45. The emission amount of the strobe light is adjusted such that an appropriate exposure amount is obtained.

The auto flash substrate 28 is replaced with the flash substrate 2
When attaching to the electronic flash 6, the elastic body 38 is first inserted between the flash substrate 26 and the auto flash substrate 28. Then, the locking claw 28a is locked in the locking hole 26a of the flash substrate 26, and the auto flash substrate 28 is temporarily fixed. Thus, the auto flash substrate 28 is roughly positioned. Next, the front cover 11 is assembled with the auto flash substrate 28 temporarily fixed. At this time, the positioning pin 11a is fitted into the positioning hole 28b, the light receiving surface 35a of the light receiving element 35 is positioned so as to face the light receiving window 17, and the auto strobe board 28 is placed between the front cover 11 and the strobe board 28. Is held by the elastic body 38. Thus, the light receiving element 35 can measure the subject light from the light receiving window 17.

In the above embodiment, the circuit pattern is formed on the front side of the strobe board 26 and the circuit parts are mounted on the back side. However, the circuit parts may be mounted on the front side, or the circuit pattern may be formed on the back side. May be. Further, the attachment of the circuit component and the formation of the circuit pattern may be performed on one surface.

In the above embodiment, the present invention is applied to the light receiving element 35 for an auto strobe. However, the present invention is not limited to this.
For example, the present invention may be applied to a light receiving element used in a shutter device or an automatic exposure control device for switching an aperture.

In the above-described embodiment, an example of a film unit with a lens has been described. However, the present invention is not limited to a film unit with a lens, and a camera for loading a brownie-sized photographic film or a 135-type photographic film cartridge. The present invention is also applicable to a camera having a structure in which the inside of the camera is covered with another external cover, such as a camera that mounts an IX240 film cartridge, an electronic still camera, and the like.

[0025]

As described above, according to the present invention, the positioning pins protruding toward the main board are provided on the inner wall of the front cover, the positioning holes are formed in the sub-board, and the front cover is assembled to the base of the main body. By inserting the positioning pins into the positioning holes of the sub-board and positioning the sub-board and the light-receiving element with respect to the light-receiving window, the light-receiving element can be easily positioned without using jigs or tools. Accordingly, the number of working steps can be reduced and the manufacturing efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a film unit with a lens.

FIG. 2 is an explanatory diagram illustrating a configuration of a strobe device.

FIG. 3 is a sectional view of a film unit with a lens.

FIG. 4 is a circuit diagram of a main strobe circuit and a strobe light control circuit.

[Explanation of symbols]

 Reference Signs List 10 Film unit with lens 11 Front cover 11a Positioning pin 17 Light receiving window 26 Strobe board 28 Auto strobe board 28b Positioning hole 35 Light receiving element 38 Elastic body 42 Main strobe circuit 47 Strobe light control circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 17/04 G03B 17/04 5F088 G03C 3/00 575 G03C 3/00 575B H01L 31/02 H05K 7/12 N H05K 7/12 V H01L 31/02 BF term (reference) 2H002 DB00 DB05 HA22 HA23 JA05 2H053 CA16 CA18 CA41 CA45 2H100 BB01 BB06 BB07 BB11 2H101 AA01 AA09 4E353 AA07 AA16 AA17 BB02 BB05 CC07 DR32 CC04 DR05 DR36 DR52 DR55 GG09 GG20 5F088 BA16 BA18 BB06 KA10

Claims (3)

[Claims] 1. A main board on which a strobe light emitting portion is held, a circuit pattern is formed, and a circuit element is mounted between a main body base in which a photographing mechanism is incorporated and a front cover covering a front surface of the main body base. A light receiving element for measuring external light through a light receiving window formed in the front cover is disposed, and a light receiving element of a camera mounted on a front surface of a sub board disposed between the main board and the front cover is positioned. In the method, a positioning pin is provided on an inner wall of the front cover toward the main board, and a positioning hole is formed in the sub-board,
A method of positioning a light-receiving element, wherein the positioning pin is fitted into a positioning hole of a sub-board by assembling the front cover to a base of the main body, and positioning of the light-receiving element with respect to the light-receiving window together with positioning of the sub-board. 2. An elastic body is provided between the back surface of the sub-board and the front surface of the main board. The sub-board is temporarily fixed to the front face of the main board together with the elastic body, and the sub-board is attached by assembling the front cover. 2. The method according to claim 1, wherein the light receiving element is held between the front cover and the main substrate via an elastic body. 3. The main board is mounted with circuit components constituting a main strobe circuit including a discharge tube, a main capacitor, a charging circuit and a trigger circuit, and the strobe measured by the light receiving element is mounted on the sub-board. 3. The method according to claim 1, further comprising mounting a circuit component constituting a strobe light control circuit for stopping light emission of the discharge tube based on an integrated value of the amount of reflected light.