Abstract: A release locking device for use in photographic cameras of the type in which an exposure meter and electro-magnetic actuating and releasing means for automatic exposure control are rendered operative in separate manner by their respective control or release switches as may be operatively associated with a display button and a shutter release button respectively. This device comprises a master switch connected between an electrical power source and a common input lead of these release switches to be closed and opened in response to an actuation and a release, respectively, of a manually operable member, thereby all of the release switches are rendered effective and ineffective at a time. In a preferred embodiment, this device is operatively associated with a shutter cocking mechanism to be actuable in automatic response to a protracting movement of the shutter cocking lever into an effective range of shutter cocking operation.

Abstract: In a camera having an exposure factor setting dial positioned adjacent a film winding lever, there is provided a safety device including a movable cover arranged to protrude upwardly from the inside of the camera housing over a top panel thereof to prevent the operator from inadvertently manually altering the setting of the dial, whereby improper actuation of the dial is prevented and the camera is made substantially fool-proof. When the cover is retracted into the camera housing by engagement of a knurled key portion thereof, the operator may actuate the dial to revise the exposure setting.

Abstract: A release locking device for use in photographic cameras of the type in which an exposure meter and electromagnetic actuating and releasing means for automatic exposure control are rendered operative in separate manner by their respective control or release switches as may be operatively associated with a display button and a shutter release button respectively. This device comprises a master switch connected between an electrical power source and a common input lead of these release switches to be closed and opened in response to an actuation and a release, respectively, of a manually operable member, thereby all of the release switches are rendered effective and ineffective at a time. In a preferred embodiment, this device is operatively associated with a shutter cocking mechanism to be actuable in automatic response to a protracting movement of the shutter cocking lever into an effective range of shutter cocking operation.

Abstract: A photographic information display apparatus for a camera provided with at least three display chips. The second chip has a number of segments less than the first chip while the segments of the third display chip are connected to a driving signal transfer line of an encoder which is not connected to the segments of the second chip. This arrangement dispenses with another driving signal transfer line for the third display chip.

Abstract: A self timer of a camera in particular a self timer for digitally controlling self timing has an indicating element responsive to pulses from a standard pulse generator to be energized intermittently and a control means for varying the period of energization and deenergization of the indicating element after a predetermined time interval. Thus, it being made possible for the photographer to know the expiration time of the self timer.

Abstract: A conversion system for a camera of a type controlled through computation of digital information. The system converts a coded digital value into a digital value of another coding. The code which comprises a gray code representing an integer part of the value and a code pattern representing a decimal part of the value is converted in such a manner that: The integer part is converted into a binary code while the decimal part is converted into a code to which a weight of 1/2, 1/4 or 1/8 is applied. With such a method of conversion employed, values set at 1/3 increment or decrement steps such as ASA film sensitivity values are readily converted into binary codes to facilitate the computing operation of the camera.