JP2001133840A - Exposure controller for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the exposure controller of a camera by which the changeover of a diaphragm is surely executed while preventing the wasteful consumption of a battery. SOLUTION: When a shutter button 33 is depressed, the locking part 13a of a shutter driving member 13 is separated from a locking lever 14, so that the shutter driving member 13 is moved in a right direction by the pressing of a spring 30. When a projected part 13b abuts on the changeover part 12a of a changeover switch 12, the changeover part 12a and a contact piece 12c are brought into contact, so that a photometric circuit 11 is actuated. An electromagnet 21 is energized in the case that the luminance of an object is large, and a diaphragm plate 18 is moved by resisting the pressing of a spring 25. A shutter blade 15 is kicked off by the protrusion 13d of the shutter driving member 13, so that exposure is executed. The moving speed of the shutter driving member 13 is adjusted by a governor mechanism 36, so that the diaphragm plate 18 is prevented from being moved during the exposure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure control device for a camera which automatically switches the aperture, and more particularly, to a camera exposure control device.
The present invention relates to a delay mechanism for securing the time required for switching the aperture.

[0002]

2. Description of the Related Art As a kind of a simple camera, various kinds of film units with lenses, in which a simple photographing mechanism such as a photographing lens and a shutter mechanism are incorporated, and a photo film is pre-loaded, are sold by the present applicant. Users can easily take print photos of good quality.
In this film unit with a lens, a fixed aperture is used in order to reduce the cost and size. For this reason, the F-number of the photographing lens becomes constant, and depending on the photographing conditions, overexposure or underexposure may occur.

[0003] This problem can be solved by incorporating a mechanism for changing the aperture diameter according to the amount of light of the subject.
Since a complicated structure leads to an increase in cost, it cannot be introduced into a simple camera such as a film unit with a lens. Therefore, Japanese Patent Application Laid-Open No. 9-5817 discloses an aperture plate having an aperture smaller in diameter than a fixed aperture aperture, and a photometric unit that measures a subject light amount and outputs a switching signal when the light amount is equal to or more than a predetermined value. There has been proposed an automatic exposure control apparatus including an electromagnet that operates when a switching signal is output. In this automatic exposure control device, when the electromagnet is operated, a magnetic attraction force is generated between the diaphragm plate and the electromagnet, and the diaphragm diameter can be switched by moving the diaphragm plate against the bias of the spring. .

[0004]

However, in the above-mentioned mechanism, since the photometry is performed when the shutter button is half-pressed and the aperture plate is switched when the shutter button is fully pressed, exposure is performed before the aperture switching is completed. May be done. In this case, some or all of the external light that would normally be exposed is blocked, resulting in underexposure and very poor image quality, or in the worst case, unexposed photographs may occur. There is.

When the lens-equipped film unit provided with the above mechanism is carried in a bag, a convex object in the bag comes into contact with the shutter button of the lens-equipped film unit, and the shutter button is turned halfway. It may be in a pressed state. In this case, the film unit with the lens performs photometry, and depending on the result, a situation occurs in which the electromagnet is energized. At this time, the battery is wasted and becomes a fatal problem in the case of a lens-fitted film unit in which the battery cannot be replaced. Further, since the solenoid inside the electromagnet is excessively heated by prolonged energization, there is a possibility of causing a fire and there is a problem in terms of safety.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide an exposure control apparatus for a camera that can reliably switch apertures while preventing unnecessary consumption of batteries. I do.

[0007]

According to a first aspect of the present invention, there is provided an exposure control apparatus including a light metering switch which is turned on when a shutter driving member moves to a light metering position set before a shutter operating position. Is turned on in response to turning on of the subject, a photometric unit that outputs a photometric signal according to the subject brightness, an aperture switching unit that switches the aperture according to the photometric signal, and at least the shutter driving member moves to the photometric position After that, the moving speed of the shutter driving member is adjusted, and a speed control mechanism for preventing the shutter driving member from reaching the shutter operation position before the aperture switching is completed by the aperture switching means is provided.

According to a second aspect of the present invention, in the exposure control device, the speed adjusting mechanism includes an escape wheel that meshes with a gear formed on the shutter drive member, and an pallet that engages with the escape wheel to adjust the rotation speed of the escape wheel. Governor mechanism.

According to a third aspect of the present invention, there is provided an exposure control device including a photometric switch which is turned on at the moment when the shutter driving member moves to a photometric position set before the shutter operating position, and responding to the turning on of the photometric switch. Metering means for measuring a subject brightness and outputting a photometric signal according to the subject brightness, aperture switching means for switching an aperture according to the photometric signal, and movement of the shutter driving member after the shutter driving member reaches the photometric position And locking means for releasing the locking of the shutter driving member in response to the completion of the switching of the aperture by the aperture switching mechanism.

According to a fourth aspect of the present invention, in the exposure control device, the aperture switching means includes an aperture plate having a small aperture opening and a large aperture opening, and a neutral position depending on whether a photometric signal is at or above a predetermined level. Diaphragm driving means for selectively moving the diaphragm plate in one direction in one direction and inserting one of the diaphragm openings on the optical axis, wherein the locking means drives the shutter when the diaphragm plate is at the neutral position. An unlocked position that is held at a locking position that prevents movement of the member, and that allows movement of the shutter driving member in conjunction with movement of the aperture plate to a position where one of the aperture openings is inserted on the optical axis. And a locking lever that moves to the right.

According to a fifth aspect of the present invention, in response to the photometric switch being turned on, charging of the strobe main capacitor is prohibited.

[0012]

Embodiments of the present invention will be described below. As shown in FIG. 1, the exposure control device of the present invention includes an aperture switching mechanism 10, a photometric circuit 11, a switch 12, a shutter driving member 13, and a locking lever 14, and constitutes an exposure mechanism together with a shutter blade 15. .

As shown in FIG. 2, the changeover switch 12 is provided with a changeover portion 12a and two contact pieces 12b and 12c. A flash circuit 16 for performing flash charging is connected to the contact piece 12b on the left side in the drawing.
The photometric circuit 11 is connected to the contact piece 12c on the right side in the drawing. A battery 17 is connected to the switching unit 12a, and the switching units 12a and 12c constitute a photometric switch for operating the photometric circuit 11. The switching unit 12a is provided so as to come into contact with the contact piece 12b when the shutter driving member 13 is stopped, and the photometric circuit 11 does not operate. The switching unit 12a includes contact pieces 12b, 12c on both sides.
When only the switching unit 12a is moved rightward in the figure, the switching unit 12a and the contact piece 12c come into contact, the photometric switch is turned on, and the photometric circuit 11 operates.

In FIG. 1, an aperture switching mechanism 10 includes:
It is composed of an aperture plate 18, an iron piece 20 and an electromagnet 21. The aperture plate 18 is provided with a shutter opening 22 formed in the camera body.
And is rotatable around the opening 18a. Further, a small aperture 23 and a large aperture 24 are formed in the aperture plate 18, and the first aperture 24 is inserted on the optical axis 26 by the bias of the spring 25 during non-photographing. Held in position. Reference numeral 27 denotes the diaphragm plate 1
Reference numeral 8 denotes a stopper provided on the camera body so as to stop at the first position. The iron piece 20 is attached to one end of the aperture plate 18 and rotates together with the aperture plate 18.

The photometric circuit 11 is connected to a light receiving element for measuring the luminance of the object. When the photometric switch is turned on, the light receiving element generates a photometric signal according to the luminance of the subject. The photometric circuit 11 energizes the electromagnet 21 when detecting that the photometric signal is equal to or greater than a predetermined value. The electromagnet 21 generates a magnetic field by a driving current from the photometry circuit 11, and the diaphragm plate 18 moves by magnetic attraction generated between the electromagnet 21 and the iron piece 20. Then, the diaphragm plate 18
Moves to the second position where the small aperture opening 23 is inserted on the optical axis 26. At this second position, the iron piece 20 and the electromagnet 21 come into contact and the aperture plate 18 stops. In addition, since the flash circuit 16 does not operate during photometry, a sufficient amount of drive current for moving the aperture plate 18 flows to the electromagnet 21.

The shutter driving member 13 has a flat plate shape, and a spring 30 is attached to the right end in the figure. On the upper part of the shutter driving member 13, a locking claw 13a, a projection 1
3b and a gear 13c are provided, and a projection 13d for opening and closing the shutter blade 15 is provided at a lower portion. The shutter driving member 13 is moved leftward in the figure by a film winding mechanism 31 built in the camera.

The locking lever 14 is connected to the shutter driving member 13
And is attached rotatably about the opening 14a. At one end of the locking lever 14, a locking portion 14b for holding the shutter driving member 13 in a charged state is provided. The locking lever 14 is held by a spring 32 attached to the locking portion 14b. A shutter button 33 is provided above the locking lever 14.
When the shutter button 33 is pressed down, the locking lever 14 rotates counterclockwise in the figure against the bias of the spring 32.

The shutter blade 15 is arranged on the front surface of the aperture plate 18 and is mounted so as to be rotatable about an opening 15a. A spring 3 is provided at one end of the shutter blade 15.
4 is attached, and the optical axis 2 is
6 is covered. Shutter drive member 13
Is moved, the tip 15b of the shutter blade 15 is kicked off by the projection 13d of the shutter driving member 13, and the shutter opening 22 is opened for a certain time. After that, the shutter blade 15 is returned to the original position by the bias of the spring 34. By this series of operations, the subject light incident from the photographing lens 35 is guided to the shutter opening 22, and the unexposed photographic film is exposed.

A changeover switch 12 is arranged above the shutter driving member 13. When the shutter driving member 13 moves rightward in the drawing, the projection 13b of the shutter driving member 13 comes into contact with the switching portion 12a. Therefore, the switching unit 12a moves rightward and comes into contact with the contact piece 12c, and the photometry circuit 11 operates.

A governor mechanism 36 is provided above the shutter driving member 13. The governor mechanism 36 includes an escape wheel & pinion 37 and an ankle 38. The escape wheel & pinion 37 is rotatably attached to the camera body. The escape wheel & pinion 37 meshes with the gear 13 c of the shutter drive member 13, so that the movement of the shutter drive member 13 can be braked.

Before the shutter is charged, the shutter driving member 13 is held at the right end in the figure as shown in FIG.
Is not distant from the projection 13b of the shutter driving member 13, so that photometry is not performed. Further, the diaphragm plate 18 is held at the first position by the bias of the spring 25.

When the film winding mechanism 31 incorporated in the camera operates, the shutter driving member 13 moves leftward in the figure against the bias of the spring 30, and as shown in FIG.
The locking portion 13a of the shutter driving member 13 is
, And the shutter drive member 13 is charged. Even in this state, the photometry is not performed because the switching section 12a of the changeover switch 12 is separated from the projection 13b of the shutter driving member 13.

When the shutter button is depressed while the shutter driving member 13 is charged, the shutter button 33 comes into contact with the locking lever 14, and the locking lever 14 is turned counterclockwise in the figure against the bias of the spring 32. Rotate in the direction. Then, the engagement between the shutter driving member 13 and the locking lever 14 is released, and the shutter driving member 13 starts moving rightward in the drawing by the bias of the spring 30. Then, as shown in FIG. 4, the switching section 12a of the changeover switch 12 moves rightward in the figure to come into contact with the contact piece 12c, and the photometric circuit 11 operates.

When the photometric circuit 11 is operated, power from the battery 17 is supplied to the photometric circuit 11, and photometry of the subject is performed by the light receiving element. When the subject luminance exceeds a predetermined value, a current flows from the photometry circuit 11 to the electromagnet 21 to drive the electromagnet 21. Then, an attractive force is generated between the electromagnet 21 and the iron piece 20, and the diaphragm plate 18 moves to the second position against the bias of the spring 25 as shown in FIG. on the other hand,
When the subject brightness is equal to or less than the predetermined value, the electromagnet 21 is not energized, and the diaphragm plate 18 is held at the first position by the bias of the spring 25. Note that the photometric circuit 11 includes an electromagnet 21
After the current is supplied, the electromagnet 21 is kept energized until the exposure is completed, so that the diaphragm plate 18 does not move even if the subject brightness changes during the exposure.

Thereafter, the shutter driving member 13 continues to move, and the projection 13d of the shutter driving member 13 contacts the tip 15b of the shutter blade 15. Then, the shutter blades 15 are kicked off and rotated, and the unexposed photographic film is exposed. When the subject brightness is equal to or less than the predetermined value, the exposure is performed through the large aperture opening 24 because the aperture plate 18 is held at the first position as shown in FIG. on the other hand,
When the subject brightness is equal to or higher than a predetermined value, as shown in FIG.
Since the aperture plate 18 has been moved to the second position, exposure is performed through the small aperture opening 23.

After the exposure is completed, the shutter driving member 1
3 continues to move rightward in the figure, and the projection 13b is
The photometric circuit is turned off apart from a. Thereafter, the shutter driving member 13 returns to the initial position shown in FIG. 2 and stops, and the shutter operation ends.

FIG. 8 shows a timing chart of the exposure control device. However, it is assumed that the diaphragm plate 18 moves to the second position. After the shutter driving member 13 is charged, the shutter button 33
Is depressed, the shutter driving member 13 moves. At the time T2, the changeover switch 12 is set to the photometric circuit 11
Side, and the photometric circuit 11 operates. Thereafter, at time T3, the electromagnet 21 is energized, and the diaphragm plate 18
Start moving to the position. Then, at time T4, the shutter blade 15 opens and closes to perform exposure.

As described above, in the exposure control device of the camera according to the present embodiment, a time lag (T4-T3) occurs from the start of the movement of the aperture plate 18 to the start of the exposure. This time lag is caused by the movement of the shutter driving member 13 and can be arbitrarily adjusted by the governor mechanism 36. By setting this time lag to, for example, a time (10 ms to 20 ms) required for moving the aperture plate 18, exposure can be performed after the movement of the aperture plate 18 is completed. Further, since the photometry is performed only while the shutter driving member 13 is moving, the photometry circuit 11 is not energized even when the shutter drive member 13 is half-pressed, so that wasteful consumption of the battery 17 can be prevented.

The operation of the above configuration will be described. The photographer operates the film winding mechanism 31 to move the shutter driving member 13. Shutter drive member 13
Is held by the locking lever 14. Thereafter, framing of the subject is performed, and when the shutter button 33 is pressed down, the shutter driving member 13 starts moving. Then, the photometry circuit 11 is operated, and when the subject is bright, the aperture plate 18 is moved.

After the time required for the movement of the aperture plate 18 has elapsed, the shutter blade 15 is kicked off and exposure is performed.
When the subject is very bright, such as when photographing outdoors on a sunny day, the exposure is through the small aperture 23. Since the exposure amount is reduced to an appropriate value by the small aperture opening 23, the photographing can be performed without overexposure. On the other hand, when the brightness of the subject is not sufficient as in the case of indoor photography, exposure is performed through the large aperture opening 24. In this case, since the exposure amount is increased, a printed photograph with proper exposure can be obtained without underexposure.

In a very dark situation such as at night, the photographer turns on a flash switch (not shown) to perform flash photography. Since the strobe circuit 16 side of the changeover switch 12 is always on, the strobe circuit 16 operates to charge the strobe main capacitor. After the completion of the flash charging is detected, the shutter button 33 is pressed down to take a picture. In this case, since the subject brightness is equal to or less than the predetermined value, the electromagnet 21 does not operate, and thus exposure is performed through the large aperture opening 24.

In the above embodiment, the speed of the shutter driving member 13 is adjusted by using the governor mechanism 36 so that the aperture can be switched reliably. However, the aperture is switched without using the governor mechanism 36. The shutter mechanism may be operated later. Hereinafter, the second embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 9, the shutter blade 40 is
It is provided on the front surface of the shutter opening 22, is rotatable about the opening 40 a, and is held by the bias of the spring 41 so that the blade 40 b covers the optical axis 26. An aperture plate 42 is provided in front of it. This diaphragm plate 42
Is rotatable about an opening 42a, and a small stop opening 43 and a large stop opening 44 are formed at both ends thereof. Protrusions 45a and 45b are provided at both ends of the aperture plate 42, and the protrusions 45a and 45b are used as a part of a shutter mechanism described later. A shaft (not shown) is attached to the back surface of the diaphragm plate 42, and the diaphragm plate 42 is held in the vertical direction in the figure by the urging of a spring 46 attached to the shaft. The aperture plate 42 is rotated 90 degrees clockwise in the figure to insert the small aperture 43 onto the optical axis 26, and rotated 90 degrees counterclockwise in the figure to rotate the large aperture 44 26.

On the front surface of the aperture plate 42, two permanent magnets 4
7a and 47b are provided, and these are arranged symmetrically with respect to the opening 42a. Also, the permanent magnet 47
The polarities a and 47b are arranged so as to have different forward polarities. For example, when the forward polarity of the permanent magnet 47a is the N pole, the forward polarity of the permanent magnet 47b is the S pole. In front of the aperture plate 42, two electromagnets 50a, 50
b is provided in the left-right direction in the figure. This electromagnet 50
The supporting plates 51a and 50b are fixed to the camera by the support plate 51 so as to overlap the permanent magnets 47a and 47b when the diaphragm plate 42 is rotated exactly 90 degrees.

The electromagnets 50a and 50b are connected to a photometric circuit 52. A switch 1 is provided at the end of the photometric circuit 52.
2 is provided, and the changeover switch 12 is used as a photometric switch for operating the photometric circuit 52. The photometric circuit 52 is designed to energize one of the electromagnets in accordance with the magnitude of the subject luminance.

The case where the polarities in front of the permanent magnets 47a and 47b are N pole and S pole, respectively, and the polarity of the electromagnets 50a and 50b are N pole will be described as an example. When the photometric circuit 52 detects that the luminance of the object is equal to or greater than a predetermined value, the electrometer 50
b is energized. At this time, the electromagnet 50b and the permanent magnet 4
7a, a repulsive force is generated, and an attractive force is generated between the electromagnet 50b and the permanent magnet 47b. The repulsive force and the suction force cause the diaphragm plate 42 to rotate clockwise in the figure against the bias of the spring 46. Then, when the diaphragm plate 42 is exactly rotated by 90 degrees, the suction force becomes maximum and the repulsion force becomes minimum, so that the diaphragm plate 42 stops at this position. At this time, the small aperture 43 is inserted on the optical axis 26.

On the other hand, when the photometric circuit 52 detects that the brightness of the object is equal to or less than a predetermined value, it turns on the electromagnet 50a. At this time, a repulsive force is generated between the electromagnet 50a and the permanent magnet 47a, and an attractive force is generated between the electromagnet 50a and the permanent magnet 47b. Therefore, the aperture plate 42 rotates counterclockwise in the drawing. Then, as described above, the stop plate 42 stops at the position just rotated by 90 degrees, and the optical axis 2
A state where the large aperture opening 44 is inserted on 6 is obtained.

Therefore, the aperture plate 42 is provided with the small aperture aperture 4.
3 is inserted on the optical axis, and a large aperture 44
Is held at a position intermediate the second position inserted on the optical axis, and by switching on different electromagnets according to the magnitude of the subject brightness, the aperture can be switched.

The locking lever 54 is arranged on the opposite side of the aperture plate 42 with the optical axis 26 interposed therebetween, and is rotatable about an opening 54a. The locking lever 54 is biased by a spring 55 and is held by a stopper 56 such that the longitudinal direction thereof coincides with the vertical direction in the figure. The shutter driving member 57 is provided on the upper portion of the locking lever 54 and has a locking portion 57a for engaging with the locking lever 54.
A shutter unit 57 b for opening and closing the shutter blades 40, and a switch unit 5 that contacts the changeover switch 12.
7c. When the film winding mechanism 31 operates, the shutter driving member 57 moves to the left in the figure against the bias of the spring 60, and the locking portion 57a moves the locking lever 54.
When the shutter button 33 is depressed, the shutter charge is released.

On the right side of the locking lever 54 in FIG.
b is provided. When the diaphragm plate 42 is rotated exactly 90 degrees, the projections 45a and 45b of the diaphragm plate 42 abut on the projections 54b, and the locking lever 54 rotates clockwise in the drawing.

When the shutter is not charged, the shutter driving member 57 is held at the right end position in the figure by the bias of the spring 60, as shown in FIG. When the photographer operates the film wind-up mechanism 31, the shutter driving member 57 moves to the left in the drawing, and the locking portion 57a of the shutter driving member 57 moves beyond the locking lever 54 as shown in FIG. Is held in. When the shutter button 33 is pressed down after framing the subject, the shutter charge is released and the shutter driving member 5 is released.
7 starts moving rightward in the figure.

Thereafter, the shutter driving member 57 is held at a position where the locking portion 57a is in contact with the tip of the locking lever 54. At this time, the shutter portion 57c of the shutter driving member 57 comes into contact with the switching portion 12a of the switch 12, and
The switching unit 12a moves to the right in the figure. And FIG.
As shown in, the switching portion 12a and the contact piece 12c abut,
The photometric circuit 52 operates.

When the subject is bright, the aperture plate 42 rotates 90 degrees clockwise in the figure and moves to the second position. Then, the projection 45a of the aperture plate 42 comes into contact with the projection 54b of the locking lever 54, and the locking lever 54 rotates clockwise in the drawing. Then, the locking lever 54 and the shutter driving member 57
Is released, and the shutter driving member 57 moves rightward in the figure by the bias of the spring 60. Thereafter, as shown in FIG. 13, the shutter portion 57b of the shutter driving member 57
Kicks off the shutter blades 40, and exposure is performed while passing through the small aperture 43. On the other hand, if the subject is dark,
The aperture plate 42 rotates 90 degrees counterclockwise in the figure and moves to the first position. Thereafter, the shutter blades 40 are kicked off by the same operation as in the case where the subject is bright, and exposure is performed in a state of passing through the large aperture opening 44 as shown in FIG.

The photometric circuit 52 is configured so that the same electromagnet is kept energized for a certain period of time after the switching section 12a and the contact piece 12c are separated, so that the aperture plate 42 does not move during exposure. ing.

Therefore, in the case of this embodiment, the aperture plate 4
Since the engagement between the shutter driving member 57 and the locking lever 54 is not released until the movement of the diaphragm plate 42 is completed,
Can be reliably moved.

[0046]

As described above, according to the first and second aspects of the present invention, photometry of a subject is performed while the shutter driving member is moving, and the aperture is switched before the shutter blades open and close. Since the moving speed of the shutter driving member is adjusted using the speed control mechanism, it is possible to reliably switch the aperture while preventing unnecessary consumption of the built-in battery.

According to the third and fourth aspects of the present invention, since the structure is such that the shutter driving member is unlocked after the diaphragm plate is moved, it is possible to reliably switch the diaphragm without using a speed control mechanism. Can be.

According to the fifth aspect of the present invention, since the strobe charging is not performed during the photometry, the aperture can be reliably switched without the photometry circuit malfunctioning due to the voltage drop due to the strobe charging.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of an exposure control device.

FIG. 2 is a schematic diagram showing a main part of an exposure control device before a shutter charge is performed.

FIG. 3 is a schematic diagram showing a main part of the exposure control device after a shutter charge is performed.

FIG. 4 is a schematic diagram illustrating a main part of the exposure control device immediately after a shutter operation is performed, and illustrates a case where a subject is dark.

FIG. 5 is a schematic diagram illustrating a main part of the exposure control device immediately after a shutter operation is performed, and illustrates a case where a subject is bright.

FIG. 6 is a schematic diagram showing a main part of the exposure control device at the time of exposure, showing a case where a subject is dark.

FIG. 7 is a schematic diagram showing a main part of an exposure control device at the time of exposure, showing a case where a subject is bright.

FIG. 8 is a timing chart of the exposure control device.

FIG. 9 is a perspective view illustrating a structure of an exposure control device according to a second embodiment.

FIG. 10 is a schematic diagram showing a main part of an exposure control device before a shutter charge is performed in a second embodiment.

FIG. 11 is a schematic diagram illustrating a main part of an exposure control device after a shutter charge is performed in a second embodiment.

FIG. 12 is a schematic diagram showing a main part of an exposure control device immediately after a shutter operation in a second embodiment.

FIG. 13 is a schematic diagram showing a main part of an exposure control device at the time of exposure when a subject is bright in the second embodiment.

FIG. 14 is a schematic view showing a main part of an exposure control device at the time of exposure when a subject is dark in the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Photometry circuit 12 Changeover switch 13, 57 Shutter drive member 14, 54 Locking lever 18, 42 Aperture plate 36 Governor mechanism

Claims (5)

[Claims] 1. An exposure control device for a camera, wherein a shutter driving member is moved in response to a shutter release operation, and the opening and closing operation of a shutter blade is started by moving the shutter driving member to a shutter operating position. A photometric switch that is turned on at the moment when the driving member moves to a photometric position set before the shutter operation position; measures the subject brightness in response to turning on the photometric switch; Photometric means for outputting a signal; aperture switching means for switching the aperture according to the photometric signal; and adjusting the moving speed of the shutter driving member at least after the shutter driving member has moved to the photometric position; Make sure that the shutter drive member reaches the shutter operation position before the An exposure control device for a camera, comprising a speed control mechanism for blocking. 2. The governor mechanism according to claim 1, wherein the speed control mechanism includes an escape wheel that meshes with a gear formed on a shutter drive member, and an pallet that engages with the escape wheel to adjust a rotation speed of the escape wheel. The exposure control device for a camera according to claim 1, wherein: 3. An exposure control device for a camera, wherein a shutter driving member is moved in response to an operation of a shutter button, and an opening / closing operation of a shutter blade is started when the shutter driving member moves to a shutter operating position. A light-measuring switch that is turned on at the moment the shutter drive member moves to a light-measuring position set before the shutter operation position; Metering means for outputting a metering signal; aperture switching means for switching an aperture according to the photometric signal; stopping movement of a shutter driving member after the shutter driving member reaches the photometric position; Locking means for releasing the locking of the shutter driving member in response to the completion of the switching of the shutter driving member. Camera exposure control device. 4. The aperture switching means selects an aperture plate having a small aperture aperture and a large aperture aperture, and an aperture plate at a neutral position depending on whether the photometric signal is at or above a predetermined level. Diaphragm plate driving means for moving the shutter driving member in one direction and inserting one of the diaphragm openings on the optical axis, wherein the locking means prevents movement of the shutter driving member when the diaphragm plate is at the neutral position. The shutter is moved to a lock release position that allows the shutter drive member to move in conjunction with the movement of the diaphragm plate to a position where one of the aperture openings is inserted on the optical axis. The exposure control device for a camera according to claim 3, further comprising a stop lever. 5. The exposure control device for a camera according to claim 1, wherein the charging of the main strobe capacitor is prohibited in response to the turning on of the photometry switch.