JPH0346643A - Method for controlling light quantity adjusting device for camera and the like - Google Patents

Abstract

PURPOSE:To perform photographing with appropriate exposure by allowing a light quantity adjusting device to carry out trial opening/closing operation which has no relation to the photographing prior to the photographing, exposure operations of a camera, etc., when the light quantity adjusting device is left inactive for a long period. CONSTITUTION:As for a control device for a half-opening shutter and each circuit mounted on the camera, etc., a control circuit 25, a motor driving circuit 26, a magnet driving circuit 27, a motor 1, a magnet 28, and a photointerrupter 13 are associated to the control of a shutter blade. When the camera, etc., is used after it is left not in use for a long period, the light quantity adjusting device is allowed to carry out non-exposure preriminary opening/closing operation which has no relation to the photographing prior to the photographing starting operation. Namely, by allowing the light quantity adjusting device to carry out non-exposure preriminary opening/ closing operation which has no relation to the photographing prior to the photographing starting operation, the mechanical sliding part, etc., of the light quantity adjusting device is reduced in resistance. Thus, the operation of the light quantity adjusting device is highly improved in accuracy at the time of photographing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of controlling a light amount adjusting device such as a shutter or an aperture mounted on a camera or the like.

[Prior Art] A photographing device such as a camera is equipped with a light amount adjusting device such as a shutter or an aperture. This kind of light amount adjustment device is
As is well known, it is a mechanism that mechanically operates the aperture blades and shutter blades at high speed.

[Problems to be Solved by the Invention] In cameras equipped with a type of light intensity adjustment device that mechanically operates the aperture blades and shutter blades at high speed, it is difficult to use the camera after it has been left unused for a long period of time. When this happens, the frictional resistance and viscous resistance against the movable members increase due to the effects of minute dust adhering to the sliding parts of the light amount adjustment device and increased viscosity of the lubricating oil during the period of non-use. At the time of the first shooting, the aperture blades and shutter blades could not be operated accurately, and as a result, the first
There was a problem that the second time I took the photo, I ended up with an inappropriately exposed photo.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a controllability of a light amount adjusting device that can solve the above-mentioned problems.

[Means for Solving the Problems] According to the present invention, when a camera or the like is used after being left unused for a long period of time, the light amount adjustment device is set to the non-exposure mode regardless of the shooting operation, prior to the shooting start operation. It is characterized by performing a preliminary opening/closing operation.

[Function] Prior to photography, the light amount adjustment device opens and closes the non-exposure element (117) independently of photography, thereby reducing the resistance in the mechanical sliding parts of the light amount adjustment device. This makes it possible to increase the precision of the operation of the light amount adjusting device at the time.

[Embodiment] Hereinafter, a light amount adjusting device whose operation is controlled based on the method of the present invention will be described, taking as an example a half-open shutter mounted on a video camera and a still camera.

In Fig. 4, 1 is a motor, 2 is a binion gear, and 3 is a motor.
4 is a reduction gear, 4 is a rack gear guided by shafts 5 and 6, and 7 is a return spring of the rack gear.

A clutch 8 is rotatably supported by the rack gear 4 via a pin 8C inserted into a hole 4a of the rack gear 4, and one end 8a of the clutch 8 is connected to the control plate 1 by a clutch spring 9.
0 pin 10a.

Reference numeral 11 denotes a pulse plate glued onto the control board 10, and the light-transmitting portion thereof is arranged to move between the light emitting element and the light receiving element of the photointerrupter 13. 12 is the control board 10
This is the return spring.

14 and 15 are shutter blades guided by 1liI 116 and 17, and pins 10b and 1 of the control board 10.
Oc passes through the elongated holes 14a and 15a, respectively.

14b and 15b are transparent parts forming shutter openings.

18 is the armature of magnet 28, and magnet 2
When the coil 19 of the clutch 8 is energized, it is applied to the left around the shaft 20, and the portion 18a pushes up the protrusion 8b of the clutch 8, thereby connecting the tip 8a of the clutch 8 and the pin 1 of the control board 10.
Performs an action to disengage from 0a.

FIG. 6 is a diagram showing the running characteristics of the aperture blades in the above-mentioned half-open shutter, where the horizontal axis is time and the vertical axis is the aperture aperture value expressed as the number of pulses detected by the photointerrupter 13. .

FIG. 5 is a block diagram showing the above-mentioned half-open shutter control device and various circuits installed in a camera, etc. The part that executes the method of the present invention is mainly a part of the control circuit 25, but the motor The drive circuit 26, magnet drive circuit 27, motor 1, magnet 28, and photointerrupter 13 are also involved in controlling the movement of the shutter blades.

In FIG. 5, 21 is a power switch signal generation circuit that detects that the camera's power switch has been pressed and generates a signal, and 22 is a power switch signal generation circuit that detects that the camera's release lock switch has been released and generates a signal. A release lock switch signal generation circuit, 23 a release signal generation circuit that detects the closing operation of a specific operation switch installed in the camera and generates a signal, 24 a timer circuit controlled by a control circuit 25, 25 a micro A control circuit having calculation and judgment functions like a computer; 29 a waveform shaping circuit that shapes the waveform of the output signal of the photointerrupter 13;
It is.

FIG. 1 is a flowchart of a program for a trial opening/closing operation of the shutter blades executed by the control circuit 25 shown in FIG.

The operation of the half-open shutter will be described below with reference to FIG. 1 and FIGS. 4 to 6.

When a battery is loaded into a camera (not shown), the power switch signal generation circuit 21 detects that the battery is loaded and issues a signal to the control circuit 25. The control circuit 25 executes a control block and issues a control signal to the motor drive circuit 26 to cause the motor 1 to rotate forward. Therefore, when the motor 1 is rotated in the normal direction (clockwise rotation in FIG. 4) and the gear 2 is rotated to the left, the rack gear 4 resists the spring 7 and starts to move to the right. Then, the clutch 8 attached to the rack gear 4 also slides to the right, so the pin 10a of the control plate 10 is pushed by the selection part 8a of the clutch 8, causing the control plate 1o to turn left against the spring 12, and the pin 10b causes the shutter to move. The blade 14 is slid to the left, the shutter blade 15 is slid to the right by the pin 10c, and as a result, the shutter opens.

At the same time, the pulse plate 11 on the control plate 10 rotates to the left, the photointerrupter 13 generates a pulse output according to the number of passages through the light-transmitting part of the pulse plate, and the counter in the control circuit 25 counts the pulse output. go. The number of output pulses of the photointerrupter 13 is the reference pulse number P. (See Figure 6), the coil 19 of the magnet 28 is energized, and the armature 18 is attracted upwards, causing the portion 18a
in order to push up the protrusion 8b of the clutch 8, the protrusions 8a and 1
The engagement of 0a is released. Therefore, the control plate 1o is rotated to the right by the return spring 12, and the shutter blades 14 and 15 are returned by the pins 10b and loc, thereby closing the shutter.

Thereafter, when the motor 1 is reversed, the rack gear 4 rotates to the left and returns to its initial position, and at the same time, the clutch 8 and the like are also returned to their initial positions, completing the series of operations.

In addition, in FIG. 6, Tm is the operation delay time of the magnet 28 from the start of energization to one coil of the magnet 28 until the closing operation of the shutter blade starts, △Pnl
is the shutter blades 14 and 15 during the delay time Tm.
or by overlapping photo interrupter 1
3 (the amount of overlap of the shutter blades).

Figure 2 shows a trial opening/closing operation program when a "signal indicating that the camera release lock is released" is used as a trial opening/closing operation start signal to cause the shutter blade to perform a trial opening/closing operation. , which is a second embodiment of the method of the present invention. In this embodiment, the control circuit 25 operates as shown in FIG. 2 in response to a pulse generated from the release lock switch signal generating circuit 22 in FIG. 5 when the release lock switch provided in the camera is released. Execute the opening/closing operation program. (The operation of the shutter mechanism in this embodiment is also the same as that explained in the first embodiment, so the explanation will be omitted.) Figure 83 shows a trial opening/closing operation program of the third embodiment of the method of the present invention. This is what is shown. In this embodiment, the trial opening/closing operation program is started in response to an arbitrary switch provided on the camera being operated as a trial opening/closing operation start signal. And, unlike the second embodiment, it is configured such that it is determined whether or not a trial opening/closing operation should be performed depending on whether a predetermined period of time or more has elapsed since the previous photographing operation. Therefore, in this embodiment, the trial opening/closing operation of the shutter mechanism is not performed unless a predetermined period of time has elapsed since the previous photographing. I can do that.

It should be noted that the above embodiments have only explained the case where the method of the present invention is applied to a half-open type shutter, but the method of the present invention can also be applied to other types of shutters (for example, focal brain shutters and non-motor driven shutters), aperture mechanisms, etc. Of course, it can also be applied to

[Effects of the Invention] As explained above, the method of the present invention allows the light amount adjustment device to operate smoothly after it has been left inactive for a long period of time. You can always take pictures with the correct exposure even after shooting.

[Brief explanation of drawings]

FIG. 1 is a flow chart showing the operation of the first embodiment of the method of the present invention, FIG. 2 is a flow chart showing the operation of the second embodiment of the method of the present invention, and FIG. 3 is the operation of the third embodiment of the method of the present invention. FIG. 4 is an exploded perspective view 1 of the mechanical structure of a half-opening shutter operated according to the method of the present invention. FIGS. FIG. 86 is a block diagram showing a part of the electrical configuration of the camera, and FIG. 86 is a diagram showing the running characteristics of the shutter blades of the half-open shutter. 1... Motor 4... Rack gear 8... Clutch 10... Control board 11... Pulse plate 13... Photo interrupter 1415... Shutter blade 18... Armature

Claims (1)

[Claims] 1. When a light amount adjustment device such as a shutter device mounted on a camera etc. is used after being left in an inoperable state for a long period of time, the light amount adjustment device is A method for controlling a light amount adjusting device such as a camera, which is characterized by performing a trial opening/closing operation unrelated to photographing. 2. The control method according to claim 1, wherein the light amount adjusting device is a half-open shutter. 3. The control method according to claim 1, wherein the light amount adjusting device is a focal plane shutter. 4. The control method according to claim 1, wherein the trial opening/closing operation is performed in response to loading of a battery or the like into the camera or the like. 5. The control method according to claim 1, wherein the trial opening/closing operation is performed in response to release of a release lock of the camera or the like. 6. The control method according to claim 1, wherein the trial opening/closing operation is performed in response to an operation of an arbitrary operation member such as the camera. 7. The control method according to claim 1, wherein the trial opening/closing operation is performed only when the period of the long-term non-operation state is longer than a predetermined time.