Bulb and time exposure control device for photographic camera

Claim 2

In a bulb exposure control device for a photographic camera comprising: a. an electronic control circuit for controlling exposure time during instant operation, including an electric power source and a power switch adapted to connect said power source to supply power to operate the control circuit; b. a shutter arranged to be sequentially cocked, opened, and closed; c. release means arranged when operated to open said shutter and to close said power switch; d. an electro magnet having a pole and connected to be energized when the power switch is closed and to be subsequently deenergized by the control circuit; and e. a pole-contactIng member arranged to be brought into contact with the pole when said shutter is cocked and to be forced away from the pole when the electromagnet is deenergized for closing said shutter, the improvement comprising: f. a bulb cam arranged to be selectively set to a first position corresponding to instant operation of the camera and to a second position corresponding to bulb operation of the camera; g. a control means connected to be shifted by the bulb cam when the bulb cam is in the second position into a position in which the control means is interlocked with the release means, and further connected to be moved by the release means, prior to the opening of the shutter, into a position to prevent the pole-contacting member from being forced away from the pole, and h. prevention means operative when the bulb cam is in the second position for preventing the power source from supplying power to operate the control circuit.

Claim 3

A device according to claim 1 in which the prevention means comprises means for preventing the power switch from being closed by said release means.

Claim 4

A device according to claim 1 in which the prevention means comprises means for opening an additional switch in series with said power switch.

Claim 5

In a bulb exposure control device for a photographic camera having an electronically controlled shutter, containing an electronic control circuit for controlling exposure time and an electromagnet controlled by said control circuit, the improvement comprising: a. a magnet lever arranged to be subjected, during the open state of the shutter, to a spring force urging the magnet lever to move away from the electromagnet against the attraction force of said electromagnet, b. a bulb cam arranged to be set selectively to either a bulb exposure position or an instant exposure position and having a face including a top portion and a bottom portion formed in the face, c. a first release lever arranged to be moved interlockingly with a manual release mechanism, d. a control lever arranged to engage the top portion of said bulb cam and to be moved in response to said first release lever for arresting movement of said magnet lever away from the electromagnet when the bulb cam is set to the bulb exposure position, and also arranged to be brought into engagement with the bottom portion of the bulb cam and not to be engaged with said first release lever when the latter is set to the instant exposure position, e. a second release lever moved by said first release lever for starting a shutter driving means, and f. a power switch comprising two contact members, one of which is arranged so as to be engageable with said control lever, the other of said contact members being arranged so as to be engageable with said second release lever, so that these two contact members are brought into contact with each other only when said second release lever is moved by the first release lever while the bulb cam is set to the instant exposure position.

Claim 6

In a bulb exposure control device for a photographic camera having an electronically controlled shutter, containing an electronic control circuit for controlling exposure time and an electromagnet controlled by said control circuit, the improvement comprising: a. a magnet lever arranged to be subjected, during the open state of the shutter, to a spring force urging the magnet lever to move away from the electromagnet against the attraction force of said electromagnet, b. a bulb cam arranged to be set selectively to either a bulb exposure position or an instant exposure position and having a face including a top portion and a bottom portion formed in the face, c. a first release lever arranged to be moved interlockingly with a manual release mechanism, d. a control lever arranged to engage the top portion of said bulb cam and to be moved in response to said first release lever for arresting movement of said magnet lever away from the electromagnet when the bulb cam is set to the bulb exposure position, and also arranged to be brought into engagement with the bottom portion of the bulb cam and not to be engaged with said first release lever when the latter is set to the instant exposure position, e. a second release lever moved by said first release lever for starting a shutter driving means, and f. a power switch comprising two contact members, one of which is arranged so as to be engageable with said control lever, the other of said contact members being arranged so as to be engageable with said second release lever, so that these two contact members are brought into contact with each other only when said second release lever is moved by the first release lever while the bulb cam is set to the instant exposure position.

Claim 7

A device according to claim 4 wherein said one contact member is engageable responsive to said bulb cam.

Claim 8

In a time and bulb exposure control device for use in a camera having an electronically controlled shutter, comprising: an electronic control circuit for controlling exposure time and an electromagnet controlled by said control circuit, the improvement comprising: a magnet lever arranged to be subjected, when the shutter is open, to a spring force urging the magnet lever to move away from the electromagnet against the attraction force of said electromagnet, a time can and a bulb cam formed integrally with each other, each cam having a face with a top portion and a bottom portion formed therein, and adapted to be selectively set to any one of three positions respectively corresponding to time exposures, bulb exposures, and instant exposures, a first release lever arranged to be moved interlockingly with a manual release mechanism, a control lever arranged to engage tHe top portion of said bulb cam and to be moved by said first release lever for arresting the movement of the magnet lever away from said electromagnet when said bulb cam is selectively set to either the time exposure position or the bulb exposure position, and also adapted to be brought into contact with the bottom portion of said bulb cam and not to be engaged with said first release lever when said bulb cam is set to the instant exposure position, a locking lever having a click lever capable of being rotated in a single direction but being limited in rotation in other directions, arranged to be brought into engagement with the bottom portion of said time cam when said time cam is set to the time exposure position, so that said control lever is locked by said locking lever in a position in which the movement of said magnet lever is arrested by said control lever, and adapted to be brought into engagement with the top portion of said time cam when the time cam is selectively set to either the bulb exposure position or the instant exposure position, whereby said locking lever is placed outside the range which will affect the control lever, a second release lever moved by said first release lever for starting a shutter driving means, and a power switch comprising two contact members, one of which is arranged so as to be engageable with said control lever and the other being arranged so as to be engageable with said second release lever, whereby these two members are brought into contact with each other only when said second release lever is moved by the first release lever when both the time cam and the bulb cam are set to the instant exposure position.

Claim 9

In a time and bulb exposure control device for use in a camera having an electronically controlled shutter, comprising: an electronic control circuit for controlling exposure time and an electromagnet controlled by said control circuit, the improvement comprising: a magnet lever arranged to be subjected, when the shutter is open, to a spring force urging the magnet lever to move away from the electromagnet against the attraction force of said electromagnet, a time can and a bulb cam formed integrally with each other, each cam having a face with a top portion and a bottom portion formed therein, and adapted to be selectively set to any one of three positions respectively corresponding to time exposures, bulb exposures, and instant exposures, a first release lever arranged to be moved interlockingly with a manual release mechanism, a control lever arranged to engage tHe top portion of said bulb cam and to be moved by said first release lever for arresting the movement of the magnet lever away from said electromagnet when said bulb cam is selectively set to either the time exposure position or the bulb exposure position, and also adapted to be brought into contact with the bottom portion of said bulb cam and not to be engaged with said first release lever when said bulb cam is set to the instant exposure position, a locking lever having a click lever capable of being rotated in a single direction but being limited in rotation in other directions, arranged to be brought into engagement with the bottom portion of said time cam when said time cam is set to the time exposure position, so that said control lever is locked by said locking lever in a position in which the movement of said magnet lever is arrested by said control lever, and adapted to be brought into engagement with the top portion of said time cam when the time cam is selectively set to either the bulb exposure position or the instant exposure position, whereby said locking lever is placed outside the range which will affect the control lever, a second release lever moved by said first release lever for starting a shutter driving means, and a power switch comprising two contact members, one of which is arranged so as to be engageable with said control lever and the other being arranged so as to be engageable with said second release lever, whereby these two members are brought into contact with each other only when said second release lever is moved by the first release lever when both the time cam and the bulb cam are set to the instant exposure position.

Claim 10

A device according to claim 6 wherein said one contact member is engageable responsive to said bulb cam.

Claim 11

A device according to claim 6 wherein said one contact member is engageable responsive to said time cam.