Title:
CINE CAMERA
United States Patent 3695752
Abstract:
A cine camera with an automatic exposure control system has a device for temporarily maintaining the aperture diaphragm in a desired stop position or for manually controlling the diaphragm. A shaft is manually displaced along a path of travel against a biasing force to provide manual engagement with the diaphragm to maintain or position the diaphragm and to disconnect the automatic exposure control circuit.
Application Number:
05/062309
Publication Date:
10/03/1972
Filing Date:
08/10/1970
View Patent Images:
Export Citation:
Assignee:
Nippon Kogaku K.K. (Tokyo, JA)
Primary Class:
Other Classes:
352/91C
International Classes:
G03B7/085; G03B9/08; G03B19/18; G03B7/08; G03B19/00; G03B7/08
Field of Search:
95/64R,64B,64C,64D 352/91,141 74/405
Primary Examiner:
Matthews, Samuel S.
Assistant Examiner:
Adams, Russell E.
Claims:
What is claimed is
1. In a cine camera having an automatically controlled diaphragm for adjusting the exposure setting dependant upon seen light, the improvement comprising: a selecting member manually positionable along a path of travel; a diaphragm actuating member; movable support means for the diaphragm actuating member responsive to the position of the selecting member to move the diaphragm actuating member into and out of engagement with the diaphragm; a manually operable diaphragm control member operatively associated with the diaphragm actuating member to adjust the diaphragm; locking means movable in response to the position of the selecting member to prevent and allow coacting movement of the manually operable diaphragm control member and the diaphragm actuating member; the selecting member biased to a first position in which the locking means prevent coacting movement between the diaphragm control member and diaphragm actuating member and the movable support means disengages the diaphragm actuating member from the diaphragm to allow automatic control of the exposure setting; first biasing means to resist displacement of the selecting member to a second position in which the movable support means engages the diaphragm actuating member with the diaphragm to maintain the diaphragm at the present setting; retaining means to hold the selecting member when displaced beyond the second position to a third position in which the locking means is moved to allow coacting movement of the manually operable diaphragm control member and the diaphragm actuating means; and releasing means to disengage the selecting member when displaced beyond the third position to a fourth position, so that the manually positionable selecting member can return to the first position.
2. The cine camera according to claim 1 further comprising an electric switch for the means for automatically controlling the exposure setting; and actuating means on the selecting member operative to actuate the electrical switch.
3. The cine camera according to claim 2 further comprising a housing for the selecting member; and the selecting member being linearly slideable within the housing when displaced from one position to another.
4. The cine camera according to claim 3 further comprising: second biasing means to bias the movable support means to move the diaphragm actuating means into engagement with the diaphragm.
5. The cine camera according to claim 4 wherein the first biasing means comprise a retaining plate biased against movement from a rest position, having a sloping surface, and a retaining member on the selecting member to contact the sloping surface of the retaining plate and urge movement of the retaining plate from its rest position.
6. The cine camera according to claim 5 wherein the retaining means to hold the selecting member in the third position comprises a fixed pawl on the retaining plate to engage the retaining member when the selecting member is displaced to the third position.
7. The cine camera according to claim 6 wherein the release means to disengage the selecting member comprises a contacting surface on the retaining plate for the retaining member, the contacting surface disposed obliquely to the path of travel of the retaining member when the selecting member is displaced from the third to the fourth position, so that the retaining member will move out of contact with the retaining plate to allow the retaining plate to return to its rest position.
8. The cine camera according to claim 7 further comprising a gear train connecting the manually operable diaphragm control member to the diaphragm actuating member.
9. The cine camera according to claim 8 further comprising third biasing means to bias the locking means to the position to prevent coacting movement of the manually operable diaphragm control member and the diaphragm actuating member; and wherein the locking means further comprise a crown gear on the manually operable diaphragm control member; and a pivotally mounted latching lever biased by he third biasing means to engage the crown gear and prevent movement of the manually operable diaphragm control member.
10. The cine camera according to claim 9 wherein the manually operable diaphragm control member is rotatably disposed about the selecting member; and further comprising spring means operative with the selecting member to return the selecting member from the fourth position to the first position.
1. In a cine camera having an automatically controlled diaphragm for adjusting the exposure setting dependant upon seen light, the improvement comprising: a selecting member manually positionable along a path of travel; a diaphragm actuating member; movable support means for the diaphragm actuating member responsive to the position of the selecting member to move the diaphragm actuating member into and out of engagement with the diaphragm; a manually operable diaphragm control member operatively associated with the diaphragm actuating member to adjust the diaphragm; locking means movable in response to the position of the selecting member to prevent and allow coacting movement of the manually operable diaphragm control member and the diaphragm actuating member; the selecting member biased to a first position in which the locking means prevent coacting movement between the diaphragm control member and diaphragm actuating member and the movable support means disengages the diaphragm actuating member from the diaphragm to allow automatic control of the exposure setting; first biasing means to resist displacement of the selecting member to a second position in which the movable support means engages the diaphragm actuating member with the diaphragm to maintain the diaphragm at the present setting; retaining means to hold the selecting member when displaced beyond the second position to a third position in which the locking means is moved to allow coacting movement of the manually operable diaphragm control member and the diaphragm actuating means; and releasing means to disengage the selecting member when displaced beyond the third position to a fourth position, so that the manually positionable selecting member can return to the first position.
2. The cine camera according to claim 1 further comprising an electric switch for the means for automatically controlling the exposure setting; and actuating means on the selecting member operative to actuate the electrical switch.
3. The cine camera according to claim 2 further comprising a housing for the selecting member; and the selecting member being linearly slideable within the housing when displaced from one position to another.
4. The cine camera according to claim 3 further comprising: second biasing means to bias the movable support means to move the diaphragm actuating means into engagement with the diaphragm.
5. The cine camera according to claim 4 wherein the first biasing means comprise a retaining plate biased against movement from a rest position, having a sloping surface, and a retaining member on the selecting member to contact the sloping surface of the retaining plate and urge movement of the retaining plate from its rest position.
6. The cine camera according to claim 5 wherein the retaining means to hold the selecting member in the third position comprises a fixed pawl on the retaining plate to engage the retaining member when the selecting member is displaced to the third position.
7. The cine camera according to claim 6 wherein the release means to disengage the selecting member comprises a contacting surface on the retaining plate for the retaining member, the contacting surface disposed obliquely to the path of travel of the retaining member when the selecting member is displaced from the third to the fourth position, so that the retaining member will move out of contact with the retaining plate to allow the retaining plate to return to its rest position.
8. The cine camera according to claim 7 further comprising a gear train connecting the manually operable diaphragm control member to the diaphragm actuating member.
9. The cine camera according to claim 8 further comprising third biasing means to bias the locking means to the position to prevent coacting movement of the manually operable diaphragm control member and the diaphragm actuating member; and wherein the locking means further comprise a crown gear on the manually operable diaphragm control member; and a pivotally mounted latching lever biased by he third biasing means to engage the crown gear and prevent movement of the manually operable diaphragm control member.
10. The cine camera according to claim 9 wherein the manually operable diaphragm control member is rotatably disposed about the selecting member; and further comprising spring means operative with the selecting member to return the selecting member from the fourth position to the first position.
Description:
FIELD OF THE INVENTION
This invention relates to a cine camera and more particularly to a cine camera having an automatic exposure control system which is capable of temporarily maintaining the diaphragm in a desired stop position and of manually controlling the diaphragm.
DESCRIPTION OF PRIOR ART
Conventional cine cameras having an automatic exposure control system often overexposed or underexposed the desired subject when subjects having greatly varying contrasts are photographed by panning the camera or when the photography is made while the operator is moving from the inside of the tunnel toward its exit. To prevent this, the operator must switch to manual diaphragm control so that the desired subject may be photographed with an optimum exposure factor. To do this, the photography must be interrupted.
To eliminate this problem, there has been proposed a cine camera provided with a device for temporarily maintaining the diaphragm at a desired or optimum stop to permit continuous photography. The cine cameras of this type may have the controls for temporarily maintaining the diaphragm and for manually controlling the diaphragm on a single operating member, so that, for example, the operating member is pressed or pulled to maintain the diaphragm and is rotated to manually control the diaphragm. However, this type of control system has the disadvantage of frequently upsetting the diaphragm setting from the desired setting because the operating member is inadvertently rotated when the operating member is pulled or pressed to maintain the diaphragm. In cine cameras of the type in which a knob is used for temporarily maintaining the diaphragm at a desired stop position, the manual control member may be inadvertently rotated when the diaphragm is held in a desired position so that the device may be damaged.
SUMMARY OF THE INVENTION
The present invention eliminates the abovementioned defects and improves the function of the device of the type described above. That is, when the automatic control is switched to the temporary maintaining of the diaphragm in a desired stop position and then to the manual control, or when the automatic control is switched into the manual control or vice versa, the continuous photography with the optimum exposure factors becomes possible. A member for temporarily maintaining the diaphragm in a desired stop position also serves as means for releasing a member which prevents the rotation of a manual control member. Thus, when the diaphragm is temporarily maintained in a desired stop position, the manual control member is not rotated. When the temporary maintaining member is moved to the manual control position, the rotation of the manual control member is permitted so that manual diaphragm control becomes possible.
In brief, the present invention provides a device for switching between the manual control and the temporary diaphragm holding for cine cameras having an automatic exposure control system characterized by the provision of a shaft which is adapted to hold the diaphragm in a desired stop or aperture position and is normally biased in one direction, a manual diaphragm control member, a retaining member for said manual control member which retains said manual control member in position and releases it when said shaft is displaced by a predetermined distance against said biasing force, an engaging member for said shaft which retains said shaft in position when said shaft is displaced further by a predetermined distance and release it when said shaft is further displaced, a rocking member which rocks in response to the displacement of said shaft, and a member for transmitting the motion of said manual control member to the diaphragm (control member) through said rocking member, whereby when said shaft is displaced by said predetermined distance against said biasing force, said rocking member is made in engagement with said diaphragm and the automatic exposure control circuit is opened.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view, partly cut away, of a cine camera embodying the present invention;
FIG. 2 is a front view partly in section, of one embodiment of the present invention;
FIG. 3 is a view looking in the direction indicated by the arrows III--III' of FIG. 2;
FIG. 4 is a view similar to FIG. 2 with the diaphragm temporarily maintained in a desired stop position;
FIG. 5 is a view looking in the direction indicated by the arrows V--V' of FIG. 2;
FIG. 6 is a view looking in the direction indicated by the arrows VI--VI' of FIG. 2;
FIG. 7 is a view similar to FIG. 2 with the diaphragm being manually controlled
FIG. 8 is a view similar to FIG. 2 illustrating the position for temporarily holding the diaphragm in a desired stop position immediately before the shaft is returned to its initial position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention will be described with reference to the accompanying drawing. Referring to FIGS. 1, 2, 3 and 5, reference numeral 1 depicts a base plate upon which are mounted devices for temporarily holding an aperture or iris diaphragm in a desired stop position and manually operating the same. A bearing 2 is securely fixed to the base plate 1 by means of a screw 3 and a manual diaphragm control member 4 rotatably fitted over the bearing 2 carries a worm 4a and a crown gear 4b. A diaphragm holding shaft 6 made integral with a diaphragm holding button 5 is slidably fitted into the bearing 2. A return spring 7 is provided for returning the shaft 6 and the button 5 to their normal positions. The leading end of the shaft 6 carries a retaining member 6a which engages with a fixed pawl 8a of a retaining plate 8 for retaining the diaphragm holding shaft in position so as to prevent the movement toward the right of the shaft 6 by the returning spring 7, a stopper 6b which engages with a depending portion 15a of a rocking plate 15, and a switch actuating member 6c for opening switch contacts 22 and 22' in a circuit provided in the automatic exposure control device (not shown).
The retaining plate 8 is carried on the base plate 1 by a shaft 9 normally biased so as to rotate in the counterclockwise direction by a torsion spring 10 whose one end is securely fixed to a projection 1a of the base plate 1. The projection 1a also serves to prevent the counterclockwise movement of the retaining plate 8. A sloping surface 8c of the retaining plate 8 for engagement with the retaining member 6a is formed along the side edge remote from the shaft 9. The fixed pawl 8a is formed at the upper side edge of the retaining plate 8 and a release portion 8b which is bent as best shown in FIG. 5 is formed adjacent to the pawl 8a. When the button 5 and the shaft 6 are pushed into the bearing 2 in the direction indicted by the arrow, the retaining member 6a engages with the fixed pawl 8a of the retaining plate 8 so that the movement of the button 5 and the shaft 6 toward the right by the urging force of the return spring 7 may be prevented. When the button 5 and the shaft 6 are moved further, the retaining member 6a is disengaged from the retaining pawl 8a and then the retaining member 6a is moved to the release portion 8b. The retaining member 6a is thus released from contact with the retaining plate 8, and both the plate 8 and member 6 return to their normal position. The retaining plate 8 is returned by rotating in the counterclockwise direction under the force of the torsion spring 10.
A gear 11 carried by a shaft 12 fixed to the base plate 1 is in mesh with the worm 4a formed on the manual diaphragm control member 4 and a gear 13 carried by a shaft 14 fixed to the base plate 1. The rocking plate 15 carried by the shaft 14 is biased by a spring 16 between the plate 15 and the base plate 1 so that the depending portion 15a thereof may be in engagement with the stopper 6b of the diaphragm holding shaft 6, as best shown in FIG. 3. A gear 17 carried by a shaft 18 fixed to the rocking plate 15 carries a rubber roller 17a which is rotated in unison with the gear 17 which is in mesh with the gear 13. The rocking assembly consisting of the rocking plate 15, the gear 17 and the rubber roller 17a rocks about the shaft 14 so that the roller 17a is made to engage with the arrow wheel 23a of a diaphragm 23 of which the rotation moves the diaphragm blades to vary the aperture of the diaphragm. The gears 11 and 13 serve to transmit the rotation of the manual diaphragm control member 4 to the diaphragm 23 through the rocking assembly. A latch lever 19 carried by a pin 20 fixed to the base plate 1 has a detent 19b for preventing the rotation of the manual diaphragm control member 4 and a contact portion 19c extending into the path of sliding movement of a contact member 6d of the shaft 6. The lever 19 is biased in the counterclockwise direction by a spring 19a to engage the detent 19b with the crown gear 4b of the manual control member 4. A snap ring 21 is fixed on the bearing 2 to prevent the manual control member 4 from axially sliding. Referring to FIG. 5, an insulating member 22a is fixed to the switch contact 22 and the switch contacts 22 and 22' are normally closed, but opened when the insulating member 22a is pushed by the switch actuation element 6c.
When the button 5 is pushed in the direction indicated by the arrow in FIG. 4, the stopper 6b of the shaft 6 is also pushed so that the depending portion 15a of the rocking plate 15 is released from the stopper 6b. Therefore, the rocking plate 15 is rotated under the force of the tension spring 16 so that the rubber roller 17a is made in contact with the arrow wheel 23a of the diaphragm of the automatic exposure device. Thus, the arrow wheel 23a is temporarily stopped by the friction between the rubber roller 17a and the arrow wheel 23a. In this case, in order to prevent the rotation of the manual diaphragm control member 4, the detent 19b of the latch lever 19 is in engagement with the crown gear 4b.
When the button 5 is further pushed as shown in FIG. 7, the retaining member 6a of the shaft 6 pushes the sloping surface 8c of the retaining plate 8 so that the latter is caused to rotate in the clockwise direction against the torsion spring 10 and then in the counterclockwise direction under the force of the spring 10 when the member 6a passes over the sloping surface 8c to reach the pawl 8a. Consequently the member 6a engages the pawl 8a so that the button 5 and the shaft 6 are held in position. In this case, the rubber roller 17a is placed in contact with the arrow wheel 23a, and the contact portion 19c of the retaining member 19 is pushed by the contact member 6d of the shaft 6 so that the pawl 19b is released from the crown gear 4b of the manual diaphragm control member 4, whereby the rotation of the member 4 may be permitted. Consequently, the rotation of the manual control member 4 is transmitted to the rubber roller 17a through the worm 4a and gears 11, 13 and 17 so that the arrow wheel 23a is rotated, thereby changing manually the aperture of the diaphragm. In this case, the switch 22 in the automatic exposure control circuit is opened in a manner discussed above.
When the button 5 is pushed to the full extent as shown in FIG. 8, the retaining member 6a slides on the upper side edge of the release portion 8b of the retaining plate 8 and then is disengaged from the upper side edge because the release portion 8b is bent so that the latter is returned to its initial position under the force of the spring 10.
When the retaining member 6a is released from the pawl 8a of the retaining plate 8 and the pressure acting upon the button 5 is released, the button 5 and the shaft 6 are returned to their initial positions under the force of the return spring 7 while the member 6a moves along the side surface of the retaining plate 8. Simultaneously, the stopper 6b is also returned to its initial position so that the depending portion 15a of the rocking plate 15 is also returned to its initial position. Consequently, the rubber roller 17a is released from the arrow wheel 23a. Furthermore, the latch lever 19 is simultaneously returned to its initial position under the force of the spring 19a and the pawl 19b engages with the crown gear 4b of the manual diaphragm control member 4. As a result, the control member 4 is prevented from rotation. The switch actuating member 6c is also returned to its initial position, so that the insulating member 22a is released whereby the switch 22 is closed.
From the description above, it is seen that, wherever the manual diaphragm control member 4 is rotated, the manual diaphragm control may be freely switched to the automatic diaphragm control. When in the automatic diaphragm control, the diaphragm may be stopped in any position, from which it can be switched into the manual control smoothly and securely.
According to the present invention, as has been pointed out, the shaft for temporarily holding the aperture diaphragm can be positioned to selectively switch between the automatic diaphragm control, the temporary holding of the diaphragm and the manual control of the diaphragm. Furthermore, except when the device is switched to manual control, the manual diaphragm control member is latched to the automatic diaphragm control and the temporary diaphragm holding member. Accordingly there is no fear that the stop can be accidentally moved from the optimum valve when the device is used to temporarily hold the diaphragm in a desired stop position. When the automatic control is switched to the temporary diaphragm holding and then to the manual control or when the automatic control is switched to the manual control or vice versa, the aperature need not be fully opened or closed. The optimum stop or aperture may be automatically or manually obtained continuously from the optimum stop prior to the switching. Thus, the continuous photography becomes possible without interruption.
This invention relates to a cine camera and more particularly to a cine camera having an automatic exposure control system which is capable of temporarily maintaining the diaphragm in a desired stop position and of manually controlling the diaphragm.
DESCRIPTION OF PRIOR ART
Conventional cine cameras having an automatic exposure control system often overexposed or underexposed the desired subject when subjects having greatly varying contrasts are photographed by panning the camera or when the photography is made while the operator is moving from the inside of the tunnel toward its exit. To prevent this, the operator must switch to manual diaphragm control so that the desired subject may be photographed with an optimum exposure factor. To do this, the photography must be interrupted.
To eliminate this problem, there has been proposed a cine camera provided with a device for temporarily maintaining the diaphragm at a desired or optimum stop to permit continuous photography. The cine cameras of this type may have the controls for temporarily maintaining the diaphragm and for manually controlling the diaphragm on a single operating member, so that, for example, the operating member is pressed or pulled to maintain the diaphragm and is rotated to manually control the diaphragm. However, this type of control system has the disadvantage of frequently upsetting the diaphragm setting from the desired setting because the operating member is inadvertently rotated when the operating member is pulled or pressed to maintain the diaphragm. In cine cameras of the type in which a knob is used for temporarily maintaining the diaphragm at a desired stop position, the manual control member may be inadvertently rotated when the diaphragm is held in a desired position so that the device may be damaged.
SUMMARY OF THE INVENTION
The present invention eliminates the abovementioned defects and improves the function of the device of the type described above. That is, when the automatic control is switched to the temporary maintaining of the diaphragm in a desired stop position and then to the manual control, or when the automatic control is switched into the manual control or vice versa, the continuous photography with the optimum exposure factors becomes possible. A member for temporarily maintaining the diaphragm in a desired stop position also serves as means for releasing a member which prevents the rotation of a manual control member. Thus, when the diaphragm is temporarily maintained in a desired stop position, the manual control member is not rotated. When the temporary maintaining member is moved to the manual control position, the rotation of the manual control member is permitted so that manual diaphragm control becomes possible.
In brief, the present invention provides a device for switching between the manual control and the temporary diaphragm holding for cine cameras having an automatic exposure control system characterized by the provision of a shaft which is adapted to hold the diaphragm in a desired stop or aperture position and is normally biased in one direction, a manual diaphragm control member, a retaining member for said manual control member which retains said manual control member in position and releases it when said shaft is displaced by a predetermined distance against said biasing force, an engaging member for said shaft which retains said shaft in position when said shaft is displaced further by a predetermined distance and release it when said shaft is further displaced, a rocking member which rocks in response to the displacement of said shaft, and a member for transmitting the motion of said manual control member to the diaphragm (control member) through said rocking member, whereby when said shaft is displaced by said predetermined distance against said biasing force, said rocking member is made in engagement with said diaphragm and the automatic exposure control circuit is opened.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view, partly cut away, of a cine camera embodying the present invention;
FIG. 2 is a front view partly in section, of one embodiment of the present invention;
FIG. 3 is a view looking in the direction indicated by the arrows III--III' of FIG. 2;
FIG. 4 is a view similar to FIG. 2 with the diaphragm temporarily maintained in a desired stop position;
FIG. 5 is a view looking in the direction indicated by the arrows V--V' of FIG. 2;
FIG. 6 is a view looking in the direction indicated by the arrows VI--VI' of FIG. 2;
FIG. 7 is a view similar to FIG. 2 with the diaphragm being manually controlled
FIG. 8 is a view similar to FIG. 2 illustrating the position for temporarily holding the diaphragm in a desired stop position immediately before the shaft is returned to its initial position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention will be described with reference to the accompanying drawing. Referring to FIGS. 1, 2, 3 and 5, reference numeral 1 depicts a base plate upon which are mounted devices for temporarily holding an aperture or iris diaphragm in a desired stop position and manually operating the same. A bearing 2 is securely fixed to the base plate 1 by means of a screw 3 and a manual diaphragm control member 4 rotatably fitted over the bearing 2 carries a worm 4a and a crown gear 4b. A diaphragm holding shaft 6 made integral with a diaphragm holding button 5 is slidably fitted into the bearing 2. A return spring 7 is provided for returning the shaft 6 and the button 5 to their normal positions. The leading end of the shaft 6 carries a retaining member 6a which engages with a fixed pawl 8a of a retaining plate 8 for retaining the diaphragm holding shaft in position so as to prevent the movement toward the right of the shaft 6 by the returning spring 7, a stopper 6b which engages with a depending portion 15a of a rocking plate 15, and a switch actuating member 6c for opening switch contacts 22 and 22' in a circuit provided in the automatic exposure control device (not shown).
The retaining plate 8 is carried on the base plate 1 by a shaft 9 normally biased so as to rotate in the counterclockwise direction by a torsion spring 10 whose one end is securely fixed to a projection 1a of the base plate 1. The projection 1a also serves to prevent the counterclockwise movement of the retaining plate 8. A sloping surface 8c of the retaining plate 8 for engagement with the retaining member 6a is formed along the side edge remote from the shaft 9. The fixed pawl 8a is formed at the upper side edge of the retaining plate 8 and a release portion 8b which is bent as best shown in FIG. 5 is formed adjacent to the pawl 8a. When the button 5 and the shaft 6 are pushed into the bearing 2 in the direction indicted by the arrow, the retaining member 6a engages with the fixed pawl 8a of the retaining plate 8 so that the movement of the button 5 and the shaft 6 toward the right by the urging force of the return spring 7 may be prevented. When the button 5 and the shaft 6 are moved further, the retaining member 6a is disengaged from the retaining pawl 8a and then the retaining member 6a is moved to the release portion 8b. The retaining member 6a is thus released from contact with the retaining plate 8, and both the plate 8 and member 6 return to their normal position. The retaining plate 8 is returned by rotating in the counterclockwise direction under the force of the torsion spring 10.
A gear 11 carried by a shaft 12 fixed to the base plate 1 is in mesh with the worm 4a formed on the manual diaphragm control member 4 and a gear 13 carried by a shaft 14 fixed to the base plate 1. The rocking plate 15 carried by the shaft 14 is biased by a spring 16 between the plate 15 and the base plate 1 so that the depending portion 15a thereof may be in engagement with the stopper 6b of the diaphragm holding shaft 6, as best shown in FIG. 3. A gear 17 carried by a shaft 18 fixed to the rocking plate 15 carries a rubber roller 17a which is rotated in unison with the gear 17 which is in mesh with the gear 13. The rocking assembly consisting of the rocking plate 15, the gear 17 and the rubber roller 17a rocks about the shaft 14 so that the roller 17a is made to engage with the arrow wheel 23a of a diaphragm 23 of which the rotation moves the diaphragm blades to vary the aperture of the diaphragm. The gears 11 and 13 serve to transmit the rotation of the manual diaphragm control member 4 to the diaphragm 23 through the rocking assembly. A latch lever 19 carried by a pin 20 fixed to the base plate 1 has a detent 19b for preventing the rotation of the manual diaphragm control member 4 and a contact portion 19c extending into the path of sliding movement of a contact member 6d of the shaft 6. The lever 19 is biased in the counterclockwise direction by a spring 19a to engage the detent 19b with the crown gear 4b of the manual control member 4. A snap ring 21 is fixed on the bearing 2 to prevent the manual control member 4 from axially sliding. Referring to FIG. 5, an insulating member 22a is fixed to the switch contact 22 and the switch contacts 22 and 22' are normally closed, but opened when the insulating member 22a is pushed by the switch actuation element 6c.
When the button 5 is pushed in the direction indicated by the arrow in FIG. 4, the stopper 6b of the shaft 6 is also pushed so that the depending portion 15a of the rocking plate 15 is released from the stopper 6b. Therefore, the rocking plate 15 is rotated under the force of the tension spring 16 so that the rubber roller 17a is made in contact with the arrow wheel 23a of the diaphragm of the automatic exposure device. Thus, the arrow wheel 23a is temporarily stopped by the friction between the rubber roller 17a and the arrow wheel 23a. In this case, in order to prevent the rotation of the manual diaphragm control member 4, the detent 19b of the latch lever 19 is in engagement with the crown gear 4b.
When the button 5 is further pushed as shown in FIG. 7, the retaining member 6a of the shaft 6 pushes the sloping surface 8c of the retaining plate 8 so that the latter is caused to rotate in the clockwise direction against the torsion spring 10 and then in the counterclockwise direction under the force of the spring 10 when the member 6a passes over the sloping surface 8c to reach the pawl 8a. Consequently the member 6a engages the pawl 8a so that the button 5 and the shaft 6 are held in position. In this case, the rubber roller 17a is placed in contact with the arrow wheel 23a, and the contact portion 19c of the retaining member 19 is pushed by the contact member 6d of the shaft 6 so that the pawl 19b is released from the crown gear 4b of the manual diaphragm control member 4, whereby the rotation of the member 4 may be permitted. Consequently, the rotation of the manual control member 4 is transmitted to the rubber roller 17a through the worm 4a and gears 11, 13 and 17 so that the arrow wheel 23a is rotated, thereby changing manually the aperture of the diaphragm. In this case, the switch 22 in the automatic exposure control circuit is opened in a manner discussed above.
When the button 5 is pushed to the full extent as shown in FIG. 8, the retaining member 6a slides on the upper side edge of the release portion 8b of the retaining plate 8 and then is disengaged from the upper side edge because the release portion 8b is bent so that the latter is returned to its initial position under the force of the spring 10.
When the retaining member 6a is released from the pawl 8a of the retaining plate 8 and the pressure acting upon the button 5 is released, the button 5 and the shaft 6 are returned to their initial positions under the force of the return spring 7 while the member 6a moves along the side surface of the retaining plate 8. Simultaneously, the stopper 6b is also returned to its initial position so that the depending portion 15a of the rocking plate 15 is also returned to its initial position. Consequently, the rubber roller 17a is released from the arrow wheel 23a. Furthermore, the latch lever 19 is simultaneously returned to its initial position under the force of the spring 19a and the pawl 19b engages with the crown gear 4b of the manual diaphragm control member 4. As a result, the control member 4 is prevented from rotation. The switch actuating member 6c is also returned to its initial position, so that the insulating member 22a is released whereby the switch 22 is closed.
From the description above, it is seen that, wherever the manual diaphragm control member 4 is rotated, the manual diaphragm control may be freely switched to the automatic diaphragm control. When in the automatic diaphragm control, the diaphragm may be stopped in any position, from which it can be switched into the manual control smoothly and securely.
According to the present invention, as has been pointed out, the shaft for temporarily holding the aperture diaphragm can be positioned to selectively switch between the automatic diaphragm control, the temporary holding of the diaphragm and the manual control of the diaphragm. Furthermore, except when the device is switched to manual control, the manual diaphragm control member is latched to the automatic diaphragm control and the temporary diaphragm holding member. Accordingly there is no fear that the stop can be accidentally moved from the optimum valve when the device is used to temporarily hold the diaphragm in a desired stop position. When the automatic control is switched to the temporary diaphragm holding and then to the manual control or when the automatic control is switched to the manual control or vice versa, the aperature need not be fully opened or closed. The optimum stop or aperture may be automatically or manually obtained continuously from the optimum stop prior to the switching. Thus, the continuous photography becomes possible without interruption.