JPH0633111U - Lens barrel - Google Patents

Abstract

(57) [Abstract] [Purpose] When the lens barrel is collapsed, it is possible to eliminate the risk of exposure due to the collapse. [Structure] From the minimum diaphragm state of the lens barrel diaphragm device,
A means for further narrowing down to a shielded state will be provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an interchangeable lens barrel for a single lens reflex camera.

[0002]

[Prior art]

 Traditionally, this type of collapsible lens barrel was used in rangefinder cameras. With this camera, there is no need to guide the light that has passed through the lens to the viewfinder, and there is no need for a mirror therefor, so there is sufficient space inside the camera body, and simply by retracting the lens part inside the body, Had no effect on the mechanism of.

[0003]

[Problems to be solved by the device]

 In the conventional technology as described above, it is easy to retract the lens barrel into the camera body, but in order to apply this to a single lens reflex camera, there is a movable mirror at the retracted position. It will be extremely difficult. First, it is necessary to retract the mirror in the lens barrel retractable space inside the camera body when retracting. Normally, the mirror does not directly illuminate the shutter section, but after retracting the mirror, the light rays that enter the lens are directly guided to the shutter section, especially when there is strong light such as direct sunlight. Had a risk of exposing the film from the shutter section.

In order to prevent this, a cap is attached to the lens barrel at the time of collapsing, but since the collapsing operation and the operation of attaching the cap are different operations, the cap may be forgotten and the exposure may occur. There was a problem that we could not dispel the fear of. The present invention has been made in view of such conventional problems, and an object thereof is to make it possible to eliminate the risk of exposure due to the collapse of the lens barrel when the lens barrel is collapsed. It is in the provision of a cylinder.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a lens barrel including a diaphragm device, which is mounted on a camera body for photographing, and a means for retracting at least a part of the lens barrel into the camera body; A means for solving the problem is to have means for changing the apparatus from a normal use state to a shielded state when the apparatus is collapsed.

[0006]

[Action]

 In the present invention, since the lens barrel is provided with a collapsing means and the diaphragm device has a means for shielding the diaphragm when the lens barrel is collapsed, the shutter is not directly exposed to the light rays coming from the lens, so The fear of exposure can be eliminated.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing an embodiment according to the present invention in which a lens barrel is attached to a camera body. In FIG. 1, the fixed lens barrel 1 has an engaging portion 1a for engaging with the camera body 31 at one end, and a screw portion 1b screwed with the distance operation ring 2 is formed at the inner diameter portion at the other end. Further, the diaphragm operating ring 8 is rotatably fitted to the outer diameter of the fixed lens barrel 1 with its movement restricted in the optical axis direction. Further, a contact portion (not shown) for transmitting an electric signal to the camera body side is provided on the inner diameter of the engaging portion 1a. The distance operation ring 2 has an operating portion 2a for focusing on the outside, a screw portion 2b screwed with the screw portion 1b of the fixed barrel 1 on the inner diameter portion, and a screw portion 2c screwed with the lens holding ring 3. It is provided. The lens holding ring 3 is formed with a screw portion 3a which is screwed with the screw portion 2c of the distance operating ring 2 on the outer peripheral portion thereof, and the lens groups 4 and 5 and the diaphragm units 6 and 7 are fixed to the inner diameter portion. The diaphragm units 6 and 7 are arranged between the lens groups 4 and 5. The lens holding ring 3 is attached to the fixed lens barrel 1 so as to be able to move linearly in the optical axis direction by a linear drive means (not shown). The squeezing operation ring 8 is rotatably attached to the fixed lens barrel 1 and has a cam portion 8a in its inner diameter portion.

As shown in FIG. 4, the squeezing lever 9 is composed of a half-moon shaped portion 9a and legs 9b and 9c extending forward and backward with the half-moon shaped portion 9a as a branch. One end of the half-moon shaped portion 9 a is rotatably attached to the fixed lens barrel 1 with a screw 10. The leg portion 9b of the aperture lever 9 extends in front of the lens and contacts the aperture drive plate 6. The contact surface of the leg portion 9b with the drive plate 6 is composed of a normal photographing area parallel to the optical axis and a retractable area lower than the normal photographing area formed through the slope.

The leg portion 9c extends rearward of the lens and abuts on a body-side unillustrated focusing lever. Further, a pin 11 is planted in an intermediate portion of the half-moon shaped portion 9a, and the pin 11 comes into contact with the cam portion 8a of the diaphragm operation ring 8. 5, 6 and 7 are aperture shape diagrams showing the open state, the minimum aperture state and the closed state of the aperture device, respectively. As shown in FIG. 5 showing the shape of the open state, the aperture blade 7 is provided with pins 7a and 7b at predetermined intervals on the front and back thereof, and the pin 7a is fitted into a hole provided in the fixed barrel 1. And 7b is engaged with the cam groove 6a of the diaphragm drive plate 6. When the diaphragm drive plate 6 is rotated, the pin 7a is rotated about the rotation center so that the diaphragm is narrowed down. The diaphragm drive plate 6 is urged by a spring (not shown) in the squeezing direction, and this urging force contacts the body side squeezing lever via the squeezing lever 9 or the pin 11. The rotation is stopped by contact with the cam portion 8a. Further, one of the plurality of cam grooves 6a of the diaphragm drive plate 6 has an engaging portion 6a 'for driving one of the plurality of blades in order to maintain the light-shielding state when retracted. .

Next, the operation of the lens barrel configured as described above will be described. Focusing is performed by manually moving the distance operating ring 2 to move the lens groups 4 and 5 to the optical axis, or by using a motor and gear train (not shown) to rotate the motor according to an instruction from the body side. Thereby, the distance operation ring 2 is rotated to move the lens groups 4 and 5 in the optical axis direction by an autofocus method. On the very close distance side of focusing, the distance operation ring 2 is stopped by a rotation limiting member (not shown), and the distance operation ring 2 is provided as shown in FIG.

In order to retract the lens barrel into the camera body, the lock device that restricts the ∞ side is released and the distance operation ring 2 is further rotated from the ∞ side as shown in FIG. can do. To perform the squeezing operation, the squeezing lever 9 and the squeeze drive plate 6 that are locked in the open state are rotated by the spring toward the small squeezing side by the rotation of the body side squeezing lever to the small squeezing side, and the The squeezing lever or the cam portion 8a of the squeezing ring 8 is brought into contact with and locked.

The mirror in the body normally guides the light, which is in the optical path and has passed through the lens barrel, to the finder side, but when the shutter button is pressed or the collapsible operation is performed, the mirror is raised and the optical path is changed. Swing out. When the lock device is released, a switch (not shown) is turned on, the signal is transmitted to the body through the lens and the body side contact, and the mirror driving device swings the mirror up. When the distance operation ring 2 is turned to the collapsible side, the lens holding ring 3 and the lens groups 4 and 5 move to the film surface side, and a part thereof is retracted into the body. At this time, the aperture unit 7 also moves at the same time, and the contact portion between the aperture drive plate 6 and the leg portion 9b of the aperture lever 9 changes from the normal photographing region to the retractable region. As a result, the diaphragm is narrowed down without moving the body side narrowing lever or the diaphragm operating ring 8. Since the step difference between the normal photographing area and the retractable area of the leg 9b is set to be larger than the amount of change when the aperture lever 9 is rotated from the open to the minimum aperture, the retracted state is set even when the open state is set. At times, the aperture is below the minimum aperture. Further, the aperture blade cam groove 6a of the aperture drive plate 6 has a shape that allows the portion 6a 'that exceeds the minimum aperture diameter to rotate more than other blades in only one place. Therefore, only one of the multiple blades completely blocks the optical path.

As a result, in the retracted state, the light is completely shielded as shown in FIG. FIG. 8 is a schematic vertical sectional view showing a second embodiment of the present invention. The difference from the first embodiment is that there is no diaphragm operation ring on the lens barrel side. The legs of the squeezing lever 9 are flush with each other in the normal photographing area and the collapsible area. The focusing operation is the same as in the first embodiment.

In the squeezing operation, the squeezing lever 9 is locked only by the body side lever. That is, the lever on the body side stops at a predetermined aperture position, and the leg portion 9c of the aperture lever 9 contacts the lever to determine the aperture value. The difference from the first embodiment in the retracting operation is that when the mirror is raised on the camera body side and the squeezing lever is moved to a position further narrowed down from the minimum aperture position, the lens side aperture is further narrowed down from the minimum aperture position. To shield the light.

Further, in the above-described embodiment, the lens barrel side distance operation ring and the lock device are manually moved to the retracted state, but the lock device is changed to click and the AF motor is operated by the operation on the body side. It is of course possible to drive the car over the click and retract it. Further, in the above-described embodiment, the cam groove of the diaphragm driving plate 6 is changed from one cam groove to the other cam groove to shield light, but it is also possible to change the shape of the diaphragm blade to shield light.

[0016]

[Effect of device]

 As described above, according to the present invention, since the diaphragm device is provided with the means for blocking the normal use state when the lens barrel is retracted, the film surface is automatically shielded when the lens barrel is retracted. is there.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a state in which a lens barrel is attached to a camera body according to a first embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view showing a first embodiment according to the present invention and showing a close-up state in which a lens barrel is attached to a camera body.

FIG. 3 is a schematic longitudinal sectional view showing a retracted position state in which the lens barrel is attached to the camera body according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a narrowing lever of the first embodiment according to the present invention.

FIG. 5 is a diaphragm shape view showing an opened state of the diaphragm device according to the present invention.

FIG. 6 is a diaphragm shape view showing a minimum diaphragm state of the diaphragm device according to the present invention.

FIG. 7 is a diaphragm shape view showing a shielding state of the diaphragm device according to the present invention.

FIG. 8 is a schematic vertical sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Fixed lens barrel 2 Distance operation ring 3 Lens holding ring 4, 5 Lens group 6 Aperture drive plate 7 Aperture blade 8 Aperture operating ring 9 Aperture lever 31 Camera body

Claims (1)

[Scope of utility model registration request] 1. A lens barrel including a diaphragm device, which is attached to a camera body and is used for photographing, a means for retracting at least a part of the lens barrel into the camera body; A lens barrel comprising: means for changing a normal use state to a shielded state.