JPS638891Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera in which focusing of a photographic lens is automatically performed.

2. Description of the Related Art Cameras have already been proposed that automatically focus a photographic lens by detecting the distance between a subject and the camera and generating an electrical signal to control an electromagnet.

In cameras of the above type, in which focus is detected during the process of pressing the release button, the electronic circuit is generally switched on at the beginning of the camera release, the electromagnet is energized and put on standby, and then focus is detected. Since the electromagnet is demagnetized when a signal is generated, the time when the electromagnet is energized is longer, which causes the battery to run out faster.Also, mechanically, a member that is activated when the electromagnet is demagnetized is closely attached to the electromagnet. This tends to make the device more complicated and is a bottleneck for miniaturization.

Japanese Patent Publication No. 46-30018 is a method for solving one such problem, but the mechanism is complicated, making it difficult to downsize, and the shutter operation continues after focus adjustment is completed. Since this is done in a traditional way, it is not possible to freely choose the composition, and the problem remains unresolved.

In addition, the same applicant proposed the structure of Japanese Patent Application No. 138732/1983 titled "Automatic Focus Adjustment Device for Camera" to solve the above problem, but in order to make the electromagnet work smoothly when implementing it, There are several drawbacks and some structural flaws cannot be avoided. In other words, when an electromagnet is excited to attract and control an operating member, if the operation of the magnetic member, that is, the attraction piece, is not always maintained in a uniform state with respect to the electromagnet, the attraction and holding position will become unstable and the adjusted position will vary. This results in non-repeatability and inaccuracy.

In view of the above, it is an object of the present invention to construct an automatic focusing camera of the above type that consumes less battery, has a simplified mechanism, ensures smooth operation, and can be made smaller.

That is, in order to achieve the above object, the present invention operates an operating member for successive focus detection in the process of pressing down the release button, and also operates an adjusting member for adjusting the photographing lens to the in-focus position, and performs the adjustment. When the member reaches the focused position, the adsorption piece that slides on the adsorption surface of the electromagnet is fitted into the adjustment member, and the electromagnet is excited to attract and hold the adsorption piece, thereby holding the adjustment member in that position. On the other hand, when the release button is released, the actuating member is returned to its initial position in order to return each member to its initial state.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, an exposure opening 1a is formed in a shutter board 1, and a cam ring 2 connected to a photographic lens is rotatably supported around the opening 1a by a spring 2a. A cam stage 2b is formed on the cam ring 2 to regulate the focal point position of the photographic lens.

The actuating member 3 is slidably supported in a groove 3a by a pin 3b, is urged upward by a spring 3c, and includes a protruding pin 3d and a protrusion 3e.

The adjustment member 4 is rotatably supported around a shaft 4a by a spring 4b, and is given dextrorotation.
It includes an actuating arm 4c, a restraining arm 4d, and a locking bent portion 4e, and the arm 4c is pushed by a pin 3d, and the arm 4d is in contact with a fixed pin 4f.

The electromagnet 5 is fixed to the substrate 1 with a screw 5a, and a coil 5b connected to an automatic focus detection electronic circuit (not shown) is inserted into the electromagnet 5. Further, an excitationable adsorption piece 5c is provided opposite to the electromagnet 5, and the restraining arm 4d is fitted into the fixing pin 5.
d.

The activation lever 6 is given left rotation by a spring 6b around a shaft 6a, and is stopped by coming into contact with a fixing pin 6c. Also, a protrusion 6d that engages with the protrusion 3e of the operating member 3, and an arm 6 for starting the shutter.
It is equipped with e.

The detection lever 7 is fitted into the shaft 6a, and the spring 7a
The protrusion 7b is rotated to the left by the slope of the protrusion 3e against the spring 7a.

The cam ring 2 is operatively connected to the actuating member 3 by known means 8, and is operable in conjunction with the reciprocating movement of the actuating member 3.

Next, the operating method will be explained. From the state shown in FIG. 1, the operating member 3
When pressed down along the groove 3a against the spring 3c, power is connected to the automatic focus detection electronic circuit in a known manner (not shown) and the circuit is activated. At the same time, the detection lever 7 is rotated to the right around the shaft 6a by the spring 7a, following the slope of the protrusion 3e.

When the actuating member 3 is pressed down, the actuating arm 4c follows the pin 3d and rotates to the right around the shaft 4a by the spring 4b, and the adjusting member 4 carries the suction piece 5c by the restraining arm 4d and closes the locking curved portion. 4e also rotates to the right around axis 4a.

By turning the detection lever 7 to the right, an electric signal (for example, electric resistance, capacitor capacity, electric panel, etc.) is generated by a known method, and when it corresponds to the focus signal of the automatic focus detection circuit, a current is applied to the coil 5b. is energized and the electromagnet 5 is excited to attract and hold the attraction piece 5c.

Therefore, the locking curved portion 4e is stopped corresponding to the focal point position, and by the subsequent depression of the actuating member 3,
By known means 8, the cam ring 2 is rotated to the right around the aperture 1a by the spring 2a, and the curved portion 4 locks the photographing lens at the focal point position corresponding to the cam stage 2b.
It is locked at e.

Furthermore, when the actuating member 3 is pushed down, the protrusion 6d of the activation lever 6 is pushed by the protrusion 3e to the spring 6b.
The shutter is rotated to the right around the shaft 6a against the force, the shutter is activated, and an exposure operation is performed.

After the cam ring 2 is rotated to the right by the spring 2a and the cam stage 2b and the curved portion 4e are engaged, the electromagnet 5 is demagnetized, but this does not affect the photographic lens.

When the actuating member 3 is released from being pressed down, the actuating member 3 moves along the groove 3a by the spring 3c, releases the pressing of the protrusion 6d, and pushes the actuating arm 4c of the adjusting member 4 by the pin 3d, against the spring 4b. Adjustment member 4
is rotated to the left around the shaft 4a, disengaging the locking curved portion 4e from the cam step 2b, and further sliding the adsorption piece 5c between the fixing pin 5d and the electromagnet 5 using the restraining arm 4d. Return to the position shown. Furthermore, protrusion 3
The protrusion 7b of the detection lever 7 is rotated to the left around the shaft 6a against the spring 7a by the slope e, and the detection lever 7 is returned to the illustrated state.

Further, the cam ring 2 is also returned to the illustrated position in relation to the actuating member 3 by known means 8, and the photographing lens also returns to its initial state, completing one operation.

FIG. 2 shows another embodiment, and members having the same effect as those in FIG. 1 are given the same numbers and symbols, and their explanations are omitted.

In the figure, the adjustment member 4 does not include a locking bent portion, but includes a pin 24g and a pushing arm 24h.

The locking lever 9 is supported by a spring 9b around a shaft 9a so as to be able to turn to the right, and has a pin 9c that engages with a push arm 24h and a curved arm 9d that engages with a cam step 2b.
, and the pin 9c is connected to the push arm 24h with respect to the spring 9b.
It is stopped in the pressed state.

The operating member 10 has a spring 10 around the shaft 10a.
b imparts dextrorotation, is rotatably supported, and includes an arm 10c that engages with the pin 24g;
It comes into contact with the fixing pin 10d and stops.

Next, the operating method will be explained. Although the parts that operate in the same way as in the case of FIG. , spring 4b
The locking lever 9 is rotated to the right by the spring 9b, and the push arm 24h releases the pressure on the pin 9c.
Turn to the right around point a, and the bent arm 9d enters the operating range of the cam stage 2b. Thereafter, when the electromagnet 5 is excited in the same way as in the case described above, the attraction piece 5c is attracted and held, the adjustment member 4 and the locking lever 9 are stopped corresponding to the in-focus position, and the photographing lens is moved to the in-focus position. is adjusted to

In the above description, the operating member 10 is used to move the photographic lens to a general subject when the in-focus position cannot be detected, or when the automatic focus detection electronic circuit does not operate due to circuit failure, battery exhaustion, etc. On the other hand, it is set at a normal focal position where the focus matches to the extent that there is no practical problem, but a detailed explanation is as follows.
Omitted.

Furthermore, if the operating member 10 is configured in connection with shutter exposure, it is possible to perform automatic focus detection when the electromagnet 5 is energized, and then to start or end the shutter exposure operation when the electromagnet 5 is demagnetized.

Of course, when the operating member 10 is configured in connection with exposure in this manner, the electromagnet 5 must be configured to be controlled by the automatic focus detection circuit and the exposure control electronic circuit.

An adjustment member that is operated by an operating member that operates for focus detection when the release button is operated.
It is fitted into a suction piece that slides with a small gap between it and the electromagnet's suction surface, so when the electromagnet is energized, it responds instantly and can hold the suction piece by suction, allowing for release operation. This type of camera, which performs automatic focus detection in the process and then changes the composition and performs a photographing operation, can be provided with a configuration that allows accurate focus adjustment. Further, the initial state is returned by the return of the release button, so even if the photographing operation is stopped after the focus detection operation is completed, everything is returned to the initial state and the next operation can be performed without any problem. Therefore, it is possible to use the viewfinder to determine the total focal position of the photographing lens in the process of pressing the release button in order to determine the focal position for the subject in line with the distance measurement mark, and then change the composition and take a photograph. Yes, it is extremely effective.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view before operation, and FIG. 2 is a plan view of the main part of the second embodiment. 1... Board, 2... Cam ring, 3... Operating member, 4... Adjusting member, 5... Electromagnet, 6... Starting lever, 7... Detecting lever, 9... Locking lever.

Claims (1)

[Scope of utility model registration request] An automatic focusing camera capable of automatically focusing a photographic lens by detecting the distance between a subject and the camera includes an actuating member that starts a focus detection operation by operating a release button, and an actuating member that follows the actuating member. an adjustment member for adjusting the photographic lens to a focused position; and an electromagnet connected to an automatic focus detection electronic circuit for detecting the focused position of the photographic lens and excited by electricity from the circuit when the focused position is detected. , comprising an adsorption piece that is fitted into the adjusting member and is activated and slides with a small gap between the adsorption surface of the electromagnet and a starting member that starts the shutter in an operation end region of the actuation member, and the electromagnet. 1. A focus adjustment device for an automatic focus adjustment camera, characterized in that when the adjustment member is excited, the adjustment member is adjusted to a focused position by attracting and holding the attraction piece.