JP2521242Y2 - Camera shutter device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a shutter device for a camera such as a small auto focus camera.

[Problems to be solved by conventional techniques and devices]

In this type of conventional camera shutter device, when it is attempted to dispose a lens advancing motor, a transmission gear group interlocking with it, a lens advancing cam, etc., on a single substrate, for example, they are all arranged around the exposure opening. Therefore, there is a problem in that the arrangement is difficult and the diameter of the lens barrel portion becomes large. Therefore, it has been considered to use two substrates and to arrange the lens feeding motor on one substrate and the transmission gear group and the lens feeding cam on the other substrate to reduce the diameter. This time, when the shutter blade and its drive mechanism are added as they are, there is a problem that the thickness of the lens barrel in the optical axis direction becomes large. Then, it was considered to incorporate the shutter blade into the lens that can be moved back and forth for focusing, that is, to attach the shutter blade to the movable lens frame to reduce the above thickness. Then, the actuator for driving the shutter blade is fixed on the substrate as it is. Then, when the inclination of the guide shaft that guides the movable lens frame is adjusted for centering or the like, a positional relationship is displaced between the drive pin of the actuator and the shutter blade opening / closing lever, and the exposure control is misaligned. There was a problem of being lost.

In view of the above problems, the present invention has an object to provide a shutter device for a camera in which a lens barrel portion can be configured compactly and exposure control does not fluctuate even when adjustment such as alignment is performed. There is.

[Means and Actions for Solving the Problems]

A camera shutter device according to the present invention comprises a lens extension motor fixed to one of a front frame and a substrate, and a transmission linked to the lens extension motor pivotally attached to the other of the front frame and the substrate. A gear group and a lens feeding cam, an AF guide shaft horizontally tilted between the front frame and the base plate so that its inclination can be adjusted, and a guide shaft integrally slidably mounted on the guide shaft. hand,
A rear lens barrel and a front lens barrel that also serve as a shutter substrate that is interlocked with the lens feeding cam, a blade driving actuator fixed to the rear lens barrel, and the front lens barrel and the rear lens barrel. By providing a shutter blade that is arranged between the shutter blades and driven by the blade driving actuator, both the diameter of the lens barrel portion and the thickness in the optical axis direction are reduced, and even if the inclination of the guide shaft is adjusted. The positional relationship between the drive pin of the shutter blade drive actuator and the shutter blade opening / closing lever is prevented from occurring.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to one illustrated embodiment.

FIG. 1 is a sectional view of an embodiment of a camera shutter device according to the present invention, and FIG. 2 is an enlarged sectional view around the blade driving actuator.

In the figure, reference numerals 1 and 2 are provided with exposure openings 1a and 2a respectively in the central portion thereof and are guided by a guide shaft 3 for zooming. The front frame and the substrate 5, which are designed to be squeezed, are fixed to the front frame 1, and the pinion 6 is fixed to the rotary shaft 5a, and a motor drive control circuit (not shown) (camera measured by distance measuring means A stepping motor for feeding the lens, which is rotated by a drive pulse (corresponding to the distance between subjects), a transmission gear group 7 pivotally mounted on the substrate 2 and meshing with the pinion 6, and 8 pivotally mounted on the substrate 2 and transmitted. The front frame 1 is meshed with the gear group 7
A lens extending cam having a circular cam portion 8a on which a focus adjustment pin screwed to a lens frame described later abuts is formed on the surface facing the lens.

Reference numeral 10 is a guide shaft for AF which is laterally bridged between the front frame 1 and the substrate 2 and the inclination of which can be finely adjusted, 11 is guided by the guide shaft 10 and moves backward by a spring 12. And the rear lens barrel supporting the rear group of the second lens group, and 13 is combined with the rear lens barrel 11 so that the relative position with the rear lens barrel 11 does not change and is substantially guided. The rear lens barrel 11, which is a front lens barrel that is guided by the shaft 10 and supports the front group of the second lens group, also functions as a shutter substrate. Reference numeral 14 denotes a focus adjusting pin which is screwed to the lens barrels 11 and 13 so as to be able to advance and retreat in a direction parallel to the optical axis, and the tip of which is in contact with the cam portion 8a of the lens feeding cam 8.

16 is a shutter control actuator (see FIG. 2) which is fixed to the rear lens barrel 11 by fixing screws 21 and 21 and is controlled by an exposure control circuit (not shown), 17
Is a shutter blade opening / closing lever pivotally attached to the rear lens barrel 11 and coupled to the drive pin 16a of the actuator 16 by a pin / slot, and swung by the actuator 16, and 18 and 19 are pivotally attached to the rear lens barrel 11. A pair of shutter blades is connected to the shutter blade opening / closing lever 17 by a pin / slot and can be opened / closed by swinging of the shutter blade opening / closing lever 17, and 20 is disposed at a predetermined position on the rear lens barrel 11 and is a shutter blade 18. When 19 and 19 are closed, they are covered by part of the shutter blades 18 and turned off.
Is a photodetector element such as a photointerrupter that is exposed to light when the shutter blade 18 further moves in the closing direction and is turned on to generate a start position detection signal.

 Next, the operation of this embodiment will be described.

First, when a shutter release switch (not shown) is turned on, a drive pulse is input to the stepping motor 5 by a motor drive control circuit (not shown), and the stepping motor 5 passes through the pinion 6 and the transmission gear group 7 to the lens extension cam 8 Rotate from the home position in the lens extension direction. Then, the lens position detection lever (not shown) rotates following the rotation of the lens feeding cam 8 to allow the shutter blade opening / closing lever 17 to move. Then, since the shutter blade opening / closing lever 17 is first swung in the shutter closing direction by the actuator 16, the shutter blades 18 and 19 move slightly from the position corresponding to the home position in the closing direction, and as a result, the light detection element 20 is turned on. Generates a start position detection signal.

In the meantime, the distance between the camera and the subject is measured by the distance measuring means (not shown) on the camera body side. Subsequently, the number of drive pulses corresponding to the distance is output from the motor drive control circuit immediately after the start position detection signal is generated. It is input to the stepping motor 5, and similarly to the above, the lens extension cam 8 is applied to the right through the pinion 6 and the transmission gear group 7. Then, the focus adjusting pin 14 abutting on the cam portion 8a of the lens feeding cam 8 is exposed in the direction along the optical axis while sliding on the cam portion 8a, and as a result, the front lens barrel 13 and the rear lens barrel 11 are exposed. They can be moved together so as to take the in-focus position. The front frame 1 and the substrate 2 guided by the guide shaft 3 are stationary during the focusing operation.

Thus, after the focusing operation is completed, the drive signal from the exposure control circuit (not shown) is input to the actuator 16,
The actuator 16 causes the shutter blade opening / closing lever 17 to swing in the shutter opening direction, and this swing causes the shutter blades 18 and 19 to be opened to perform exposure. Then, after a predetermined time, the actuator 16 receives a signal from the exposure control circuit and swings the shutter blade opening / closing lever 17 in the closing direction, and the shutter blades 18 and 19 are closed by this swinging, and the exposure is completed.

The operation of the present embodiment has been described above. However, in the present embodiment, the lens extension motor 5 is fixed to one of the front frame 1 and the substrate 2 and the other lens extension motor 5 is mounted.
Since the transmission gear group 7 and the lens moving-out cam 8 interlocking with are pivotally attached, the diameter of the lens barrel portion becomes small. Also, the rear lens barrel 1 which also serves as a shutter substrate between the front frame 1 and the substrate 2
1, front lens barrel 13 is provided, that is, shutter blades 18, 19
Is attached to the movable rear lens barrel 11, the thickness of the lens barrel portion in the optical axis direction is also reduced. Therefore, the lens barrel portion can be made compact. Further, since the actuator 16 for driving the shutter blade is fixed to the rear lens barrel 11, even if the tilt of the AF guide shaft is adjusted for centering or the like, the drive pin 16a of the actuator 16 and the shutter blade opening / closing lever 17 The positional relationship between and does not shift. Therefore, even if the adjustment such as the alignment is performed, the exposure control is not affected.

[Effect of device]

As described above, the camera shutter device according to the present invention has a practically important advantage that the lens barrel can be made compact, and exposure control does not occur even if adjustment such as alignment is performed. There is.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a camera shutter device according to the present invention, and FIG. 2 is an enlarged sectional view around the blade driving actuator. 1 ... Front frame, 2 ... Substrate, 3 ... Guide axis, 4 ... Zoom ring, 5 ... Stepping motor, 6 ... Pinion, 7
...... Transmission gear group, 8 …… Lens feeding cam, 10 ……
AF guide shaft, 11 …… Rear lens barrel, 12 …… Spring, 13 ……
Front lens barrel, 14 ... Focus adjustment pin, 16 ... Actuator, 17 ... Shutter blade opening / closing lever, 18,19 ... Shutter blade, 20 ... Photodetector, 21 ... Fixing screw.

Claims (1)

(57) [Scope of utility model registration request] 1. A lens feeding motor fixed to one of a front frame and a substrate, and a transmission gear group and a lens pivotally attached to the other of the front frame and the substrate and interlocking with the lens feeding motor. A feeding cam, an AF guide shaft horizontally tilted between the front frame and the base plate so that its inclination can be adjusted, and an AF guide shaft slidably mounted on the guide shaft. Between the rear lens barrel and the front lens barrel that also function as the shutter substrate that is interlocked with the feeding cam, the blade driving actuator fixed to the rear lens barrel, and between the front lens barrel and the rear lens barrel. A shutter device for a camera, comprising: a shutter blade that is arranged and driven by the blade driving actuator.