JPH0729537U - Camera lens barrel - Google Patents

Abstract

(57) [Abstract] [Purpose] When taking a picture, the members that compose the lens barrel are automatically projected to be used as a lens hood. A first helicoid screw is provided between a fixed barrel 1 and a movable barrel 2 which is fitted therein, and a lead direction which is opposite to the first helicoid screw between the movable barrel 2 and a lens barrel 3 which is fitted therein. If a second helicoid screw having the above is provided and the lens barrel 3 is prevented from rotating by the engagement of the linear guide member 21, the movable barrel 2 itself is largely projected in the optical axis direction by the rotation of the movable barrel 2. At the same time, the front end of the movable barrel 2 is used as a lens hood by retracting the lens barrel 3 by about 1/2 of the movable barrel 2 for adjusting the focus of the photographing lens 5.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a lens barrel used in a small camera such as a compact camera.

[0002]

[Prior art]

 It is necessary to use a lens hood, as is well known, in order to obtain clear pictures with good contrast without flare when taking pictures under direct sunlight or on a waterside or a snow surface with a lot of unnecessary reflected light. A lens hood, which is sold separately, is commercially available for each user, and the user always buys and carries it with the camera.

[0003]

[Problems to be solved by the device]

 However, the lens hood, which is sold separately, is often lost or forgotten to be used, especially for beginners, and is not fully utilized.

Therefore, a camera has been proposed in which a lens hood is built in the camera body so that the lens hood is inevitably set to a predetermined position when taking a photographing posture. The proposal by the 62-217229 gazette is one example.

However, the camera proposed above is limited to a camera including a lens barrier device, and is not widely applicable to general cameras.

As a result of solving the above problems and improving the present invention, an object of the present invention is to provide a lens barrel of a camera that can use a part of the lens barrel as a lens hood in conjunction with the focus adjustment operation of a photographing lens. Is.

[0007]

[Means for Solving the Problems]

 The above-described object is to provide a fixed barrel fixed to the camera body, a rotatable movable barrel to be fitted into the fixed barrel via a first feeding device, and a second movable device to the movable barrel via a second feeding device. The lens barrel includes a lens barrel that is fitted in and prevented from rotating, the first feeding device and the second feeding device are in mutually opposite movement directions, and the lens barrel is held by rotationally feeding the movable barrel. This is achieved by a lens barrel of a camera characterized by adjusting the focus of a photographing lens and projecting the movable barrel to a position where it can be used as a lens hood.

[0008]

【Example】

 An embodiment of the lens barrel of the present invention will be described with reference to FIGS.

Reference numeral 1 denotes a cylindrical fixed body that is integrally fixed to the camera body, and has a female helicoid screw 1a screwed on the inner circumference thereof and a pair of notched guide grooves 1b at symmetrical positions in the horizontal direction.

Reference numeral 2 denotes a cylindrical movable body that is fitted inside the fixed body 1, and has a large gear having an external helicoid screw 2a screwed to the female helicoid screw 1a and a tip circle slightly smaller than the outer diameter of the male helicoid screw 2a. A female helicoid 2c having a moving direction opposite to that of the male helicoid screw 2a is formed on the inner circumference of 2b.

The fixed barrel 1 and the movable barrel 2 constitute a helicoid screw which is a first feeding device having a relatively large lead amount by screwing the female helicoid screw 1a and the male helicoid screw 2a together.

Reference numeral 3 denotes a lens barrel on which a lens frame 4 containing a taking lens 5 is screwed, and a male helicoid screw 3a screwed onto the female helicoid screw 2c of the movable barrel 2 is screwed on the outer circumference thereof. A pair of guide grooves 3b are provided at symmetrical positions in the vertical direction.

The movable barrel 2 and the lens barrel 3 are screwed with the female helicoid screw 2c and the male helicoid screw 3a, and the lead amounts in the opposite directions are approximately 1/2 of the lead amount of the first helicoid. And a helicoid screw which is a second feeding device.

Reference numeral 21 denotes a ring-shaped linear guide member that is attached to and supported by the movable barrel 2, and has a pair of linear guides 21a and 21b projectingly provided at respective symmetrical positions in the horizontal and vertical directions.

As shown in FIG. 2, the linear guide member 21 is rotatably engaged with and supported by the flange portion 2d at the rear end of the movable barrel 2, and the linear guide 21a is fitted in the guide groove 1b of the fixed barrel 1. On the other hand, the straight guides 21b are slidably engaged with the guide grooves 3b of the lens frame 3, respectively.

FIG. 3 shows an example of a method of attaching the straight guide member 21 to the movable barrel 2. Therefore, three spacers having screw holes are provided on the front surface of the straight guide member 21, that is, on the protruding side of the straight guide 21b. A pair of fixing plates 22 provided with 23 are temporarily rotatably supported by one set screw 24 in advance and rotatably supported. First, as shown in FIG. At the position where it is rotated, the fixed barrel 1 is inserted from the rear side and inserted into the flange portion 2d of the movable barrel 2. Thereafter, as shown in FIG. 3 (B), the fixed plate 22 is rotated outward and each spacer 23 is moved. A stopper female screw 25 is attached to each spacer 23 in a state of sliding contact with the flange portion 2d, and is tightened together with the stopper female screw 24 so that the linear guide member 21 and the fixed plate 22 hold the flange portion 2d.

Therefore, although the linear guide member 21 integrally moves forward and backward with the rotation of the movable barrel 2, the rotation is blocked by the engagement with the fixed barrel 1, and as a result, the lens barrel 3 is moved. The function of guiding straight ahead will be fulfilled.

A lens barrel drive motor 31 has a shaft 32 to which a propeller 33 for LDP1 is attached, and a photointerrupter 34 for LDP1 generates a signal LDP1. The LDP 1 is for finely detecting the rotation angle (amount) of the lens barrel drive motor 31, and the rotation of the motor 31 causes the propeller 33 to rotate, and the photo interrupter 34 electrically outputs the rotation amount as a pulse. The number of propeller blades is six in this figure, so six pulses are generated for one rotation of the motor 31. Reference numeral 35 is a pinion directly connected to the motor 31, and the rotation of the motor 31 is transmitted to a gear 43 coaxially integrated with the gear 42 via gears 36, 37, 38 and 42, and to a protruding portion 21c of the linear guide member 21. The large gear 2b of the movable barrel 2 is driven via the drive gear 44 attached to the shaft. A propeller 40 for LDP2 is attached to the shaft 39 of the gear 38, and a signal LDP2 is generated by a photointerrupter 41 for LDP2. The operation of the lens barrel drive motor 31 is controlled by the signals LDP1 and LDP2.

Further, 52 is a shutter, and 53 is a motor for driving the shutter 52, which is mounted on the lens barrel 3 and is connected to a printed board 54 on the outer periphery thereof via a flexible printed board 51 which is inserted into the slit hole 1c of the fixed barrel 1. ing. The flexible printed circuit board 51 changes its bending position as the lens barrel moves forward and backward, and makes electrical connection with the motor 53 that moves relative to the circuit board 54.

Reference numeral 61 denotes the outline of the camera body, and 62 and 63 are decorative rings attached to the movable barrel 2 and the lens barrel 3, respectively.

Next, the focus adjustment operation of the lens barrel will be described.

When the camera is not ready to take a picture, the movable barrel 2 and the lens barrel 3 are in a retracted position with the taking lens 5 as shown in the upper part of the optical axis XX in FIG. It is in.

The lens barrel drive motor 31 rotates in conjunction with the shutter release operation of the camera body, and its power is driven from the gears 36, 37, 38 and 42 through the gear 43 to support the linear guide member 21. Rotate the gear 44.

Therefore, the movable barrel 2 is rotated and moved in the optical axis direction by the action of the first helicoid screw described above. The movable barrel 2 can be moved forward or backward freely by switching the rotation direction of the lens barrel drive motor 31, while the drive gear 44 is always in mesh with the gear 43 long in the optical axis direction.

Since the photographing lens 5 is moved from the retracted position to the photographing position, when the movable barrel 2 is rotated in the direction of advancing in the optical axis direction, the lens barrel 3 is moved by the action of the second helicoid screw described above. It moves backward relative to the movable barrel 2 in a straight traveling state.

The rotation operation of the lens barrel drive motor 31 is controlled by the above-mentioned signals LDP1 and LDP2 to automatically set the taking lens 5 to its in-focus position.

As a result, the movable barrel 2 and the lens barrel 3 are set in a photographing state with the imaging lens 5 as shown in the lower part of the optical axis XX in FIG. Achieves the same light blocking effect as when a separate lens hood is attached.

Further, the depth of the movable barrel 2 indicated by the symbol D in the drawing becomes larger as the amount of extension of the taking lens 5 is made larger, that is, the closer to the near side, so that the image is combined with the antireflection effect by the female helicoid screw 2c. You can also expect a light-shielding effect that corresponds to the corners.

In the present embodiment, an example in which a helicoid screw is used for the above-mentioned first and second feeding devices has been described. However, instead of each of the above-mentioned helicoid screws, a spiral cam and an engagement therewith. It is also possible to use a feeding mechanism constituted by a pin, and the lead amount of each of the first and second feeding devices is the most efficient depending on the focal length of the taking lens 5 to be mounted and the configuration of the lens barrel. It is selected so as to obtain a light shielding effect.

[0030]

[Effect of device]

 The present invention provides a compact lens barrel for a camera that can be used as a lens hood by automatically projecting a part of the lens hood when taking a picture, so that the lens hood is always used and the contrast is always maintained. It has become possible to realize a compact camera that produces excellent photos.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a lens barrel of the present invention.

FIG. 2 is a cross-sectional configuration diagram of the lens barrel.

FIG. 3 is an explanatory view of a main part of the lens barrel.

[Explanation of Codes] 1 Fixed barrel 1a, 2c Female helicoid screw 1b, 3b Guide groove 2 Movable barrel 2a, 3a Male helicoid screw 2b Large gear 3 Lens barrel 4 Lens frame 5 Photographing lens 21 Straight guide member 21a, 21b Straight guide 22 Fixing plate 23 Spacers 24, 25 Set screw 31 Lens barrel drive motor 44 Drive gear 51 FPC board 52 Shutter

Claims (2)

[Scope of utility model registration request] 1. A fixed barrel fixed to a camera body, a rotatable movable barrel fitted in the fixed barrel via a first feeding device, and a second barrel feeding device to the movable barrel. And a lens barrel that is prevented from being rotated so that the first lens barrel and the second lens barrel are held by the rotational movement of the movable barrel. A lens barrel for a camera, wherein the movable lens barrel is projected to a position where it can be used as a lens hood while adjusting the focus of a photographing lens. 2. The lens barrel of a camera according to claim 1, wherein the first and second feeding devices are constituted by helicoid screws screwed with each other or pins engaging with each other and a spiral cam.