JPH0364853B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera, and particularly to an improvement for moving a photographic lens.

Conventionally, the helicoid method was the most common method for extending the camera lens barrel, but since it is difficult to process helicoids, an alternative method is to use a bar method to extend the shooting lens barrel. It is appearing.

An example of a system employing this method is shown in FIG.
FIG. 1 is a vertical cross-sectional view showing a conventional example of a mechanism for extending a lens barrel using a bar system. First, this will be explained.

101a, 101b, and 101c constitute a photographing lens group, 110 is a spacer, and 102 is a lens barrel. 103 is a bar fixed to the lens barrel 102, and 104 is an ∞ adjustment screw also screwed to the lens barrel 102. The ∞ adjustment screw is used when adjusting the focus of the photographic lens. 10
5 indicates a shutter and 106 indicates a film. Reference numeral 107 is a front base plate, and 108 is a rear base plate, and the bar 103 is fitted and supported by these two types of base plates.

A cam member 109 is fitted onto the rear base plate 108 and is rotatable around the optical axis of the photographic lens. The ∞ adjustment screw 104 is in contact with the face cam surface 109a of the cam member 109, and the lens barrel 102 is always urged in the direction of the cam member 109 by a coil spring 111.

In the lens barrel extension mechanism configured as described above, when the cam member 109 is rotated by a transmission mechanism (not shown), the adjustment screw 104 follows the cam surface 109a of the cam member 109, thereby causing the extension movement of the lens barrel 102. will be held.

When the lens barrel extension mechanism using the bar method described above is adopted, the lens barrel is supported on a so-called cantilever, but in order to prevent the lens barrel from deflecting, the above-mentioned ∞ adjustment screw that receives pressure from the cam surface is The position should be as close to the base of the bar as possible. In addition, in order to satisfy the optical performance such as eccentricity accuracy of the photographic lens, it is necessary to keep the distance between the supporting parts of the bar that is fitted and supported at two points as long as possible in order to minimize the sagging of the lens barrel. In order to remove the bar and the bar support from the effective optical path of the photographing lens, the bar must be located away from the optical axis of the photographing lens.

For this reason, if a cam member that rotates around the optical axis of the photographic lens is provided as in the past, a large cam member would be required and a large space would be taken up inside the camera, making it extremely difficult to downsize the camera. As it turned out, it had some flaws.

The present invention has been made in view of the above circumstances, and
The camera is equipped with a straight-travel bar, a photographic lens that moves guided by the straight-travel bar, and a cam member that rotates around the straight-travel bar to move the photographic lens, making it easy to move the photographic lens in a small space. It is an object of the present invention to provide a camera lens moving device that can be moved.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view of a main part of a camera showing an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view thereof. In FIGS. 2 and 3, 1 is a photographic lens, and 2 is a lens barrel that holds the photographic lens 1. In FIG. A straight bar 3 is fixed to the lens barrel 2, and both ends of the bar 3 are supported by receiving portions 23a and 24a of a front base plate 23 and a rear base plate 24 to guide the extending and retracting movement of the photographic lens 1. . 5 is a light projecting lens, and 6 is a light receiving lens, which are arranged apart from each other by a certain base line length. Reference numeral 7 denotes a rotating ring which is fitted on the inner diameter of the protrusion 12 of the rear base plate 24 and is rotatable around the bar 3. The rotary ring 7 has a first cam surface 7a for extending the photographic lens and a second cam surface 7b for IRED (Infra Red Emitting Diode) scanning, which will be described later. It has a gear part 7c for rotating and charging itself. An ∞ adjustment screw 4 screwed to the lens barrel 2 is in contact with the first cam surface 7a, and the cam surface 7a is in contact with the first cam surface 7a.
In conjunction with the rotation of the lens barrel 2, the lens barrel 2 is extended and retracted.

Reference numeral 11 denotes an IRED for projecting light, which is fixed to an IRED lever 8, and the IRED lever 8 is rotatable around a fulcrum shaft 9. The IRED lever 8 has
An adjusting member 10 for preliminary adjustment of IRED scanning is screwed together and is in contact with the second cam surface 7b of the rotary ring 7. Further, the IRED lever 8 is biased counterclockwise by a spring 22.

13 is a charge lever, dowels 14 and 15
The rack part 13a provided on the charge lever 13 is engaged with the gear part 7c of the rotary ring 7. The charge lever 1
3 is transmitted to a charge mechanism (not shown), and is urged in the return direction by a spring 21.

17 is a finder objective lens, 18 is a frame reflector, 19 is a frame plate, and 20 is an eyepiece lens, and 17, 18, 19, and 20 constitute an Albada finder. A viewing frame 19a, a distance mark 19b, etc. are deposited on the frame plate 19. Further, on the front side of the frame plate 19, a needle-shaped tip 8a integrally formed with the IRED lever 8 is arranged so as to be movable up and down. 16 is a light-receiving SPC that receives the near-infrared light projected from the IRED 11.

The operation of the autofocus camera configured as above will be explained.

First, in conjunction with film winding, the charge lever 13 is moved rightward by a charge mechanism (not shown), and at the same time, the rotating ring 7 is moved to the right.
also rotates clockwise. After the charge lever 13 has moved by a certain amount, a tensioning means (not shown) is actuated to lock the charge lever 13 and the rotating ring 7 as well. As the rotating ring 7 rotates, the ∞ adjustment screw 4 screwed onto the lens barrel 2 rides on the first cam surface 7a of the rotating ring 7, and the lens barrel 2 is moved forward. , it will stop at a very close position. On the other hand, since the adjustment screw 10 screwed to the IRED lever 8 rides on the second cam surface 7b of the rotating ring 7, the IRED lever 8
rotates clockwise around the fulcrum shaft 9. accordingly
The IRED 11 moves upward and stops at a position where it focuses on an object at close range.

Next, when the tension holding the charge lever 13 is released by the release operation, the charge lever 13 begins to return to the left by the spring 21, and at the same time, the rotating ring 7 also rotates counterclockwise. start. Adjustment member 1 screwed into IRED lever 8 by counterclockwise rotation of rotating ring 7
0 also follows the second cam surface 7b of the rotating ring, the IRED lever 8 begins to rotate counterclockwise about the fulcrum shaft 9. As a result, IRED11
starts scanning from top to bottom and IRED
SPC 16 receives near-infrared light emitted from 11
When the output reaches the maximum, a distance measurement completion signal is issued, and a lens barrel stopper (not shown) is activated to stop the retracting operation of the lens barrel 2, and the photographing lens 1 is brought to a position at a predetermined extended amount. is retained.

At this point, after the distance measurement completion signal is output, actually move the lens barrel 2.
Since there is a mechanical delay time until the lens stops at a predetermined position, it is necessary to advance the IRED11 for scanning by an amount corresponding to the amount of extension of the lens barrel during this delay time. There is. As this advance adjustment means, there is an adjustment member 10 screwed to the IRED lever 8.
By changing the screw connection amount of 0, each position of IRED11 corresponding to the extended position of lens barrel 2 can be adjusted.
Scanning can be performed while IRED11 takes the lead.

Here, the rotating ring 7 provided with a cam surface 7a for extending and retracting the photographic lens barrel 2 is configured to rotate not around the optical axis of the photographic lens but around the central axis of the bar 3. Therefore, there is no need for a large cam member that rotates around the optical axis of the photographing lens as shown in the conventional example shown in FIG.

In addition, since the rotating ring 7 is placed away from the optical axis of the photographing lens, the IRED
The scanning cam surface 7b is connected to the rotating ring 7.
It is also possible to provide the device integrally with the device, which simplifies the mechanical structure.

In the above embodiment, the straight bar 3 corresponds to the straight bar of the present invention, the photographic lens 1 corresponds to the photographic lens of the present invention, and the cam surface 7a corresponds to the cam member of the present invention.

As described above, according to the present invention, it is possible to provide a camera lens moving device that can easily move a photographic lens in a small space, and is very effective in making the camera more compact.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing a conventional example of a lens barrel extension mechanism using a bar system, Fig. 2 is a perspective view of main parts of a camera showing an embodiment of the present invention, and Fig. 3 is a main longitudinal sectional view of Fig. 2. It is a front view. 1... Shooting lens, 2... Lens barrel, 3... Straight bar, 4...∞ adjustment screw, 7... Rotating ring,
7a...Cam surface for extending the lens, 7b...Cam surface for driving the distance measuring mechanism, 7c...Gear portion, 13...
charge lever.

Claims (1)

[Claims] 1. Lens movement of a camera characterized by having a straight bar, a photographic lens that moves guided by the straight bar, and a cam member that rotates around the straight bar to move the photographic lens. Device.