JPS59189328A - Specifying device for maximum aperture diameter of shutter - Google Patents

Abstract

PURPOSE:To improve the precision of range finding in a low brightness state and facilitate dimming to a short-distance subject by incorporating a means which specifies the maximum aperture diameter of a shutter all the time corresponding to the subject distance in a shutter device. CONSTITUTION:A cam ring 20a turns associatively with the distance adjustment of a lens barrel 20. This cam ring 20 has different-height cam surfaces corresponding to ranges of, for example, infinity -1.9, 1.9-1.3, 1.3-0.9, and 0.9-0.5 m. Therefore, a driven level 21 which is energized to the cam surface by a spring 25 oscillates around a shaft 22 corresponding to the height of the cam surface. This oscillatory movement allows a member 24 to move left and right in a figure through a pin 23, so parts of a step part 24c formed at one terminal of the member 24 which extend into the movement track of a pin 8 for driving shutter blades 1 and 2 change. Namely, the downward movement of the pin 8, i.e. the maximum aperture diameter of the shutter blades 1 and 2 is specified by the movement of the step part 24c according to the distance ranges.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shutter device in which the maximum aperture diameter is regulated according to the photographing distance, and more particularly to a maximum aperture diameter regulating device for a shutter that is used as a program shutter and performs an irregular program shutter that prioritizes distance.

For a long time, cameras have been pursued to be more compact, multi-functional, and automated. For example, in programmable shutter type compact cameras, automatic winding, built-in auto-strobe, or auto-focus devices have become mainstream. A major future challenge is to develop an exposure control system that is optimal for such a comprehensive multi-functional camera.

Against this background, the present applicant filed the patent application No. 57-1488.
In issue No. 81 (published on August 27, 1981), we proposed a new camera shutter actuation device. Furthermore, there are many points that need to be improved regarding the exposure meter Kaizan 1.

For example, as can be understood from the program shutter method, in the conventional program shutter, the shutter speed and aperture value are uniquely determined according to the subject brightness.
In low-light conditions, the aperture becomes larger, resulting in a shallower depth of field and more out-of-focus photos.

-! In the combination of a tablogram shutter and an autofocus device, the depth of field becomes shallow due to the size of the aperture, so distance measurement at low 4 degrees, li!Ilf
It gives you peace of mind that improves your self-esteem. However, in general, the distance measurement accuracy of the autofocus device itself tends to deteriorate depending on the brightness of the subject, which is contrary to the above requirement.

Furthermore, in the combination of a program shutter and an auto flash device, the aperture aperture is determined only by the subject brightness, regardless of the subject distance, making it extremely difficult to adjust the light for close-up subjects at low brightness. Become.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a shutter device that solves the above-mentioned drawbacks and difficulties.

This purpose can be achieved by incorporating a means into the shutter device that constantly regulates the maximum aperture diameter of the shutter in accordance with the subject distance.Furthermore, when this shutter device is used as a program shutter, the program characteristics can be adjusted in accordance with the subject distance. It functions as a new and different irregular program shutter.

Hereinafter, the present invention will be described in detail based on preferred embodiments of the accompanying drawings.

Figure 1 is a perspective view of essential parts showing an embodiment of the maximum aperture diameter regulating device for a shutter according to the present invention, and 1 and 2 are shutter blades that are swingable around a shaft 3 and have slots in some of them.
1a and 2a.

Reference numeral 4 denotes a three-pronged lever that can swing freely around a shaft 5, and is given a counterclockwise swinging habit by the biasing force of a spring I applied between it and a support piece 6 of the camera body fixing part.

Pins 8, 9 and 10 are fixed to the ends of the arms 4a, 4b and 4c of the trident lever 4, respectively, and perform the functions described below. Pl is a holding plunger which is biased to protrude by a spring (not shown) and acts to be retracted by electromagnetic drive, and P2 is a closing plunger which is movable in the protruding direction and is actuated to the retracted position by electromagnetic drive. , a locking piece 1 is provided at the tip of the movable arm of the plungers Pi and P2, respectively.
1 and 12 are attached. The pins of each arm of the three-pronged lever 4 are such that the pin 8 is located in the cam slot 1a, 2a of the shutter blade 1, 2, and the pin 9.1 is located in the cam slot 1a, 2a of the shutter blade 1, 2.
0 are locking pieces 11 and 12 of plungers Pi and P2, respectively.
It is something that is engaged with. As is clear from the shape of the shutter blades, this embodiment is entirely configured with a program shutter, and the light-receiving element is arranged to measure the light reflected from the film surface, for example, to perform TTL direct photometry.

20 is a cam ring 2 that is linked to the distance ring on the lens barrel.
0a is provided. One end of a driven lever 21 is driven along the cam surface of the cam ring 20a with the shaft 22 as a pivot center.

A pin 23 is fixed to the other end of this driven lever 21, and is engaged with one end of a maximum opening diameter regulating member 24 by this pin 23.

This maximum aperture diameter regulating member 24 has pins 27 and 28 fixed to the camera body and a slot 24a provided therein.
, 24b so as to be slidable in the left-right direction in the figure, and is biased to the left in the figure by a spring 25 that is hooked onto a pin 26 fixed to the camera body.

The other end of this member 24 faces within the movement trajectory of the pin 8 for driving the shutter blade 1°2, and the downward movement of the pin 8 [
A step portion 24c is provided for regulating l(I) (the maximum opening diameter of the shutter blades 1 and 2).

The operation of the maximum aperture diameter regulating device for a shutter having such a configuration will be explained based on the time chart of FIG. 2. First, when a pulse is generated by a shutter release signal such as a shutter button, the plunger P1 is driven. , the locking piece 11 is retracted to the retracted position. Therefore, the three-pronged lever 4 is unlocked from the pin 9 and the locking piece 11, and the three-pronged lever 4 swings counterclockwise under the action of the spring I. Accordingly, the pin 8 of the arm 4a is moved into the slot 1a. , 2a, the seven blades 1 and 2 are swung in opposite directions around the shaft 3. As a result, exposure of the subject light from the lens barrel 20 to the film is started. At the same time, T
When TL direct photometry is performed and an appropriate exposure amount is reached, a shutter closing pulse is generated by a control circuit, which will be described later, and in response, the plunger P2 is activated in 4-wheel drive. When the plunger P2 is driven, its plunger arm, that is, the locking piece 12, is driven to the retracted position, and the three-pronged lever 4 is swung clockwise against the spring 5 via the pin 10 of the arm 4c of the three-pronged lever 4. make it move. For this reason, the shutter blade 1
, 2 are returned to the closed position. Then, after a predetermined time has elapsed since the driving of the plunger P2 or the shutter closing pulse, the plunger P1 is turned off, the locking piece 11 locks the bottle 9, and after a further predetermined time, the plunger P
2 is turned off to reach the initial state.

The above is the operation of the program shutter, but below is the maximum opening of the shutter (l regulating member 2) which is the main part of the present invention.
The effect of No. 4 will be explained.

The cam ring 20a is linked to the adjustment of the distance of the lens barrel 20.
rotates. The cam surface of this cam ring 20a is, for example, ω ~ 1.9 m, 1.9 m ~ 1.3 m, 1.3
Surfaces with different heights are formed in the ranges of m to 0.9 m and 0.9 m to 0.5 m.

Therefore, the driven lever 21, which is biased by the spring 25 against this cam surface, swings around the shaft 22 in accordance with the height of this cam surface. This rocking movement is caused by the bin 23
Since the member 24 is moved in the left-right direction in the drawing through the step 24c formed at one end of the member 24, the portion facing the movement trajectory of the bin 8 for driving the shutter blades 1 and 2 changes. . Here, the movement of the member 24 is configured to be linked to the distance adjustment of the lens barrel 20;
If an autofocus device is built in, the member 24 may be moved based on distance information from the autofocus device.

Due to the movement of the stepped portion 24c, the downward movement of the bin 8, that is, the maximum opening diameter of the shutter blade 1.2 is regulated according to the distance range.

Figure 3 shows the program (9) ram characteristics that are changed due to this regulation.
．． ':l The maximum aperture diameter of the shutter blades 1 and 2 is opened up to F2.8 (Ll) up to 1.9 m to 1.9 m.
In the range of 3 m, the maximum opening diameter is limited by F4 (L2
), and the same goes for F5.6 from 1.3m to 0.9m.
(L3), and from 0.9 m to 0.5 m, it is limited to F8 (L4), and the maximum aperture diameter of the shutter blades 1 and 2 is determined according to the shooting distance. It becomes a priority irregular program shutter.

In this programming method, the strobe is automatically emitted when the shutter speed is 1/30 seconds or more, so that photographs with proper exposure are always obtained. (See FIG. 4) FIG. 4 is a logic circuit that controls the operation of the embodiments illustrated so far.

In the figure, each flip-flop circuit FF1 to FF5 (
Hereinafter, they will simply be referred to as F'F1 to FF5. ) is reset in the initial state, but (10) In this state, the pulse P in response to the shirt release is FF
When input as a set pulse of I, the Q terminal of FF1 outputs #1 // f. At the same time, the pulse P is sent to the counter C via the OR circuit OR1 (hereinafter simply referred to as OR1).
k is reset, and from this point on, the clock pulses from the clock pulse generator CL are counted.

The output from FF1 is input to AND circuit A1, but A1
Since the other input terminal of is 0, FF2 is not set.

Therefore, FF3 is also in the reset state, and from the 4 terminals 〃1〃
Since the output of FF1 is input to AND circuit A4,
At the moment when is set by the pulse P, an output "1" is obtained from the AND circuit A4, which drives the plunger P1 described above.

In this way, the photometric integration circuit consisting of the photodetector PD, capacitor C1 and operational amplifier OP1 is activated, and the capacitor C
1 is charged with a current corresponding to the intensity of the subject light to the photodetector PD, and (11) when the appropriate exposure amount is reached, an appropriate exposure output is obtained from the comparator consisting of the operational amplifier OP2, which is output by the 17 circuit OR2.
(hereinafter simply referred to as OR2), the OR2 output becomes ika'/1//, and the A1 output is "1".
", FF2 is set. Therefore, AND circuit A
5 output becomes 1'', and the plunger P2 is driven 5 times to close the shutter.

When the FF'2 becomes 1, the delayed output goes through the delay circuit and resets the counter C. When the predetermined time T1 has elapsed from this point, counter C gives l'1〃 output to A2, so A2 fully outputs "1". Then, since FF3 is set, the q terminal output becomes l'0〃, so A4 Output is “0”
As a result, the plunger P1 is turned off.

After a predetermined time T2 that is longer than T1 has elapsed, counter C outputs 1 to one terminal of AND circuit A3, and at this point A3 outputs 71'' (12), so the point terminal output of FF4 becomes 〃0〃, so the output of AND circuit A5 is 〃0〃.

As a result, plunger P2 is turned off.

Further, when the time T3 has elapsed since the reset state by the release pulse P, the counter C gives an output 1" to the set terminals of OR2 and FF5, forcibly closing the shutter, and transmits the flash signal F via the AND circuit A6.
L is sent to an interception device (not shown). This time T3 is, for example, 1/30 second, and is used to prevent unnecessary long exposure that would cause camera shake and to determine the low brightness level of automatic strobe light emission.

Note that the times TI, T2. Regarding T3, it is added to the time chart in FIG.

In the above description, a program shutter that also serves as a d1 aperture has been described, but it goes without saying that the present invention can also be applied to a program shutter in which the aperture and shutter are made up of separate members.

(13) It goes without saying that the shutter mechanism and control circuit may also be modified in various ways.

As described above, according to the device of the present invention, since the shutter has a maximum aperture limited according to the photographing distance,
The depth of field in the close-range area becomes deeper, making it possible to correct out-of-focus errors.

In particular, when the device of the present invention is applied to a program shutter and fC is used, it becomes an irregular program shutter that prioritizes distance, and TTL
By combining direct metering and TTL direct metering auto strobe (low-brightness automatic flash), it not only helps with the above-mentioned out-of-focus effects, but also makes it easier to adjust the light at short distances with the auto strobe because the aperture is small at close range. It becomes possible to take pictures even at distances where mechanical flashmatic is difficult.

Furthermore, even when the autofocus device is built into the camera, the aperture becomes small at close range (14), so the autofocus division accuracy is reduced, which is very advantageous in terms of cost and manufacturing.

Also, when stopping down to F8 in Leica format, the circle of confusion falls within the range of 0.05φ from about 0.6m to 1m, and at close distances it is 1.
Since focus adjustment can be covered by simply setting a point, it is possible to provide a high-performance shutter device with an unprecedented high f111, which makes close-range photography extremely easy compared to conventional program-type cameras.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts showing the configuration of an embodiment of the present invention, FIG. 2 is a time chart explaining the principles of the embodiment shown in FIG. 1, and FIGS. ) are the program characteristic diagrams for the embodiment shown in FIG. 1 during high brightness (a) and low brightness (b), and FIG. 4 shows the logic for controlling the operation of the embodiment shown in FIG. Each circuit is shown below. 1.2...Shutter blade 4...Three-pronged lever I,
25... Spring 20... Lens barrel 21... Followed lever (15) 24... Shutter maximum opening diameter regulating member P1... Holding plunger P2... Closing plunger FF1 to FF5. ...Flip-flop circuit A1 to 6
... AND circuit OR1, OR2 ... OR circuit OPl, OF2 ... operational amplifier PD ... light-receiving element C ... counter Applicant Fuji Photo Kohki Co., Ltd. (16) Shirt 7-Shi Lease °゛- F-2”. Ijitsubo, rkoma Bite (mouth) No. Z Fig. 2゜FJ 4.5;/) δ /+ 16 2
2-+" 1st fertilizer

Claims (1)

[Claims] 1) In a shutter device that moves to an open position by shutter release and then moves to a closed position after a predetermined exposure, based on shooting distance information such as the amount of extension of the lens barrel or an autofocus detection signal, A maximum opening diameter regulating device for a shutter, characterized in that a maximum opening diameter regulating means having a predetermined regulating position is arranged so as to face an opening movement track of the locking device. 2) Holding the shutter blade in the closed position when not driven; 1. A holding electromagnetic means releases the holding of the shutter blade in the closed position during driving, and a shutter release spring forces the shutter blade to normally open. In a shutter device consisting of electromagnetic means for closing, the maximum aperture diameter regulating means, whose predetermined regulating position is determined based on the amount of extension of the lens barrel or photographing distance information such as an autofocus detection signal, is moved to open the shutter device. 7 Yatsuta's maximum opening diameter regulating device is characterized by being placed facing into the orbit.