JPS6333122B2 - - 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.

A camera that detects the distance between a subject and the camera, generates an electrical signal to activate an electromagnet, and automatically focuses the photographic lens is extremely convenient for the user.

Various cameras of the above type have been proposed, but
In the case of a method that detects the in-focus position using an electric signal obtained from a rangefinder using a conventional movable mirror and sets the photographic lens to that position,
Unless a predetermined brightness is required and the contrast of the subject is not less than a predetermined value, it will be difficult to detect the in-focus position. However, such a subject exists as a real scene, and in the above method, there is a possibility that the subject is determined to be at an infinite distance or a close distance. In view of the above, the present invention provides that when an electric signal for detecting the focused point cannot be obtained,
The object of the present invention is to provide a device that sets a so-called regular focus position (or fixed focus position) that focuses on a certain range.

That is, when an automatic focus detection signal cannot be obtained from a component that operates for automatic focus adjustment, the photographic lens is set at the regular focus position by displacing the component that operates for automatic focus adjustment to a second position different from the one used during automatic focus detection. It is something to do.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present description will be described in detail with reference to drawings showing one embodiment of the present description.

In FIG. 1, the actuating member 1 is slidably supported in a groove 1a by a pin 1b, urged upward by a spring 1c, and includes a protruding pin 1d, a spring-loaded pin 1e, and a protrusion 1f.

The operating member 2 is rotatably supported by a shaft 2a on the operating member 1, is given left-turning ability by a spring 2b, and includes an operating arm 2c and a stop arm 2d, with the stop arm 2d hitting the pin 1d. It is stopped close to each other.

In addition, a fixing pin 2e is attached to the operating area of the base of the operating arm 2c.
stands out.

The adjustment member 3 is rotatably supported by a shaft 3a, is given levorotation by a spring 3b, and includes a pin 3c that engages with the operating arm 2c, a bent portion 3d, a latch portion 3e, an upwardly protruding pin 3f, and a step. The side surface of the stepped portion 3g comes into contact with the fixing pin 3h and is stopped.

The focus scanning member is rotatably supported by a shaft 4a, has an arm 4b engaging a pin 3f, and is operatively connected to a movable mirror of a rangefinder (not shown).

The electromagnet 5 is fixed by a screw 5a,
While the current is supplied to the coil 5b, it is excited.

The control member 6 is rotatably supported by a shaft 6a, given dextrorotation by a spring 6b, and includes a movable iron piece 6c that faces the electromagnet 5 and can be attracted to it. In this manner, the movable iron piece 6c is pressed against the electromagnet 5 against the spring 6b. It also has a claw part 6d that engages with the latch part 3e and a curved part 6e at the tip, from a position where it is attracted to the electromagnet 5, to a first position where it engages with the latch part 3e, and a second position where it engages with the stepped part 3g. Operates to position 2.

Note that an automatic focus detection electronic circuit (not shown) is provided, and when the focus scanning member 4 operates the movable mirror of the rangefinder and detects an in-focus point, it cuts off the current to the electromagnet 5 and synchronizes with the movable mirror. The operating adjustment member 3 is then stopped.

Next, the operating method will be explained. From the state shown in FIG. is closed, an automatic focus detection electronic circuit (not shown) is activated, and the electromagnet 5 is excited to attract the movable iron piece 6c.

When the operating member 1 is further pushed down, the movable iron piece 6c is unfastened from the electromagnet 5, and the operating member 2 is then
Push the pin 3c with the operating arm 2c and adjust the adjustment member 3.
is rotated to the right around the axis 3a against the spring 3b,
Next, when the base of the operating arm 2c comes into contact with the pin 2e,
It turns to the right around the shaft 2a against the spring 2b, and the operating arm 2c sequentially retreats from the operating range of the pin 3c.

As described in Japanese Patent Application No. 53-12701 filed by the same applicant on the same date, the adjustment member 3c operates the arm 4b by means of a pin 3f to rotate the focus scanning member 4 around the axis 4a when turning to the right. When the pin 3c is released from the operating arm 2c, the adjustment member 3 starts to turn to the left and then turns to the right. When the focus point position detected during is reached, the focus detection electronic circuit is activated and the electromagnet 5 is demagnetized.

When the electromagnet 5 is demagnetized, the movable iron piece 6c is no longer attracted to the control member 6, and the control member 6 rotates to the right around the shaft 6a by its own spring 6b, and the first position where the claw portion 6d engages with the latch portion 3e is caused. position, and stops the adjusting member 3 in accordance with the in-focus position.

That is, the curved portion 3d of the adjustment member 3 protrudes into the movement path of the photographic lens, and is configured to control the focal point position in accordance with the rotation angle around the axis 3a. Therefore, the latch portion 3e is connected to the claw portion 6d.
The position of the focused point detected by the movable mirror corresponds to the position of the focused point detected by the movable mirror.

When the actuating member 1 is further actuated, JP-A-51-
As shown in Japanese Patent No. 121326, after the curved portion 3d of the adjusting member 3 is stopped corresponding to the in-focus position, the photographing lens is operated, and the lens engages with the curved portion 3d and is stopped.

When the adjusting member 3 rotates to the right, if the movable mirror does not detect the in-focus position because the subject is dark or there is no contrast, the adjusting member 3 rotates to the right to the end, and the photographing lens When the electromagnet 5 is demagnetized in this position, the control member 6
turns to the right without engaging the latch part 3e,
The claw portion 6d engages with the stepped portion 3g and stops at the second position.

Then, when the photographic lens is operated by the subsequent operation of the actuating member 1, the curved portion 6e of the control member 6 determines the focal point position of the photographic lens in place of the curved portion 3d.

Here, a method for demagnetizing the electromagnet 5 when the above-mentioned focal point position is not detected will be described in detail. When the adjusting member 3 turns to the right to the terminal end, the patent application filed by the same applicant on the same date is in the terminal position.
53-12702 No. 53-12702, an electric contact (switch 30 in FIG. 3) as shown in FIG. is determined by a known discrimination circuit, and if no in-focus point detection signal is obtained, the electromagnet 5 is demagnetized.

It is preferable that the focal point of the photographic lens controlled by the curved portion 6e be set at a position that is generally referred to as a regular focal position, where the focal point matches a relatively wide range of depth. In this case, it is possible to take pictures without failure.

When the actuating member 1 is released, it returns upwards by the spring 1c, opens the switch S and deactivates the automatic focus detection electronic circuit, and at the same time moves the control member 6 against the spring 6b by a known method (not shown). Then, the movable iron piece 6c is turned to the left around the shaft 6a, and the movable iron piece 6c is pressed against the electromagnet 5, and the state shown in FIG. 1 is returned.

In FIG. 2, members having the same effect as those in FIG. 1 are indicated by the same numbers, and detailed explanations are omitted.

In the figure, the control member 6 has a pushing arm 26,
It is given dextrorotation by a spring 6b and controlled by an electromagnet 5.

The second adjustment member 23 is coaxially fitted under the adjustment member 3 so as to be rotatable about the shaft 3a, and includes a curved portion 23b replacing the curved portion 6e of the control member 6 and an arm 23c that engages with the pushing arm 26. There is.

Next, to explain the operating method, the control member 6
When the pawl portion 6d engages with the latch portion 3e, the push arm 26 does not engage the arm 23c, but when it engages with the stepped portion 3g, the push arm 26 engages with the arm 23c and 2
The adjusting member 23 is turned to the left around the axis 3a, and the bent arm 23b is adjusted to the common focal position P of the photographing lens.

As is clear from the above description, according to the present invention,
The adjustment member and control member that operate for automatic focus adjustment are linked, and when an automatic focus detection signal cannot be obtained, the control member is moved to a second position different from that used during automatic focus detection.
Even if automatic focus detection is not performed when the camera lens is moved to the position of It enables photographing, reduces failures, provides an inexpensive device with a simple structure and few failures, and is extremely effective.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention, and FIG. 2 is a plan view showing another embodiment. DESCRIPTION OF SYMBOLS 1... Actuation member, 2... Operation member, 3... Adjustment member, 4... Focus scanning member, 5... Electromagnet, 6...
...Control member, 23...Second adjustment member.

Claims (1)

[Claims] 1. In an automatic focusing camera capable of automatically focusing a photographic lens by detecting the distance between a subject and a camera, a focus scanning member that is operated for focus detection and a focus scanning member that is operated for focus detection, and a focus scanning member that operates in conjunction with an operating member to control the photographic lens. an adjusting member having a latch portion and a stepped portion for determining the in-focus position and the normal focal position of the lens; and a locking portion that protrudes into the operating path of the photographing lens and engages with the lens when the lens is operated; If the focal point position is detected while the adjustment member is operating in one direction using the signal from the automatic focus detection electronic circuit that detects the focal point position of the photographic lens, it is demagnetized when the adjustment member is operated in the opposite direction, and the focal point position is detected. an electromagnet that is demagnetized at the end of the operation in one direction when not detecting the position; The first position where the first part of the locking part adjusts the first part of the photographing lens to the in-focus position, and when the in-focus position is not detected, the first part engages with the step part of the adjustment member, and the first part of the first part of the locking part engages with the stepped part of the adjustment member. A focusing device for an autofocusing camera, comprising: a second position for adjusting the lens to a normal focus position by means of a member protruding into the operating path of the photographing lens;