Abstract: An analogue audio signal input to a transmission unit 1 is band limited into a frequency band lower than that of a main signal pass with a low-pass filter 21 and then converted into a digital value with a sampling clock lower than the main signal pass by an analogue/digital converter 22. All bits of the converted digital signal are inverted by an inverter 23. The digital signal input to a reception unit 3 via a transmission channel 100 is inverted by inverter 42 and is digital/analogue converted by digital/analogue converter 43 with the sampling clock lower than the main signal pass. The resultant signal is band limited into the low frequency band through a low-pass filter 44 and then output to a level comparator 45. A low-pass filter 46 band limits the signal for the main signal pass into the low frequency bang. The level comparator 45 compares the output level of the low-pass filter 44 with that of the low-pass filter 46.

Abstract: A camera provided with a rear surface switch includes a pressure plate. The pressure plate maintains film in a flattened alignment within a film exposure region of the camera. An external cover encloses a rear of the pressure plate. A switch includes a movable operational member that protrudes from the cover. An electrical conductive member is attached to the rear of the pressure plate. An electrical signal is output in accordance with the movement of the operational member. The operational force resulting from the movement of the operational member is supported by the pressure plate.

Abstract: A real image viewfinder of an optical device includes an eye piece through which an optical axis may be viewed with respect to a target frame. The target frame may be used for centering an optical image on an image forming plane and also for autofocus of the optical device. The real image viewfinder includes a first prism for redefining an optical axis within the optical device. The first prism has a pair of reflective planes joined about a first ridge line. The first ridge line generally includes a number of manufacturing flaws which are noticeable by the photographer. Thus, viewfinder components are shifted by a predetermined amount to present the first ridge line in an area of the viewfinder which is different from the target frame as viewed through the eye piece. Likewise, the real image viewfinder includes a second prism having a second ridge line which is also shifted away from the target frame as viewed through the eye piece.

Abstract: An indicator device comprises an indicator rotatively driven by an electrical driving source, such as a stepping motor or the like, a plurality of indexes indicated by the indicator to indicate various photographing information, and changing mechanism for changing indicating positions of the indicator. The changing mechanism includes an operating member operated in order to start a rotation of the indicator, an operating member for commanding a rotational direction of said indicator, and driving control mechanism for controlling a rotation of the indicator in accordance with operation of the operating members.

Abstract: A camera having a film counter according to the present invention includes a display device which displays information related to frames of a film; a detector which detects that a battery has been replaced while the camera is loaded with the film; a volatile memory which stores information related to a number of remaining unexposed frames of the film; and a controller which causes the display device to display the number of remaining unexposed frames according to the information stored in the volatile memory until the battery is replaced, and switches the display device to display a frame number in a forward count display, in which a frame number increases for each exposure, in response to a signal generated by the detector upon replacement of the battery.

Abstract: A camera viewfinder device adapted for use in a camera having a photographic lens for photographing a subject and a rangefinder system for producing rangefinding information. The viewfinder device includes a display unit having multiple display parts that indicate a rangefinding spot within a viewfinder field and a control device that selectively controls the illumination and indication states of the multiple display parts of the display unit to produce the rangefinding spot based on information about photographic conditions including the focal length of the photographic lens and the rangefinding information. Also provided is a display device for use in a camera having a photographic lens for photographing a subject and a rangefinder system for producing rangefinding information.

Abstract: A miniaturized collapsible zoom camera changes viewfinder magnification in accordance with a change in the photographic magnification. The camera is equipped with a collapsible cam tube to cause a first lens group, which rotates around the optical axis, to move from a collapsed position to a position just before a minimum magnification position. Likewise, a zoom cam tube causes the first lens group, which rotates around the optical axis, to move from the minimum magnification position to a maximum magnification position. Sector gears are formed on the outer circumference of the collapsible cam tube and the zoom cam tube. Furthermore, the camera is equipped with a cam tube drive gear which cooperates with the sector gears. A drive motor causes the drive gear to rotate. Another gear cooperates only with the sector gear of the zoom cam tube while a variable power and movement mechanism causes variable power operation in the viewfinder.

Abstract: In a system comprising photographing apparatus for recording photograph information and reproducing apparatus for reproducing the photograph information, control information recorded in the photographing apparatus forces the reproducing apparatus to reproduce photograph information that would otherwise be excluded from reproduction based on consideration of a characteristic of the photograph information.

Abstract: A device for detecting perforations in film includes a camera body or other optical instrument body. A pressure plate is disposed at a rear of the body and has a channel that allows access of a sensor output to detect and read film position via the recognition of such perforations in the moving film as it passes through the camera or optical instrument body. The pressure plate maintains the alignment of the film relative to the body. An installation board is aligned and mounted adjacent a rear of the pressure plate. A sensor is attached to the installation board. The sensor is disposed to face a section of the film having perforations through the channel of the pressure plate as the film moves along a film path. The sensor transmits electronic signals corresponding to the position of perforations of the film as the film moves along the film path. The invention provides for the efficient and economical construction of a device having a sensor for detecting perforations in film.

Abstract: Attaching window glass to a window used in photometry without degrading the external appearance of a camera, with the aim of simplifying the photometric optical system. The device has a photometric unit which conducts photometry on the subject region and which is provided inside the housing of the camera, an aperture stop is formed integrally with the housing at a position in front of the photometry unit. The aperture stop restricts the amount of incidental light on the photometry unit. A window glass is attached, from the inside of the housing, to cover the aperture region of the aperture stop. Further, the aperture stop is provided with a tapered surface which is formed so that the aperture region expands from the outside of the housing to the inside.

Abstract: A camera capable of trimming photographing has an electric-powered zoom lens, an operating device for zooming the electric-powered zoom lens, a trimming photographing device for obtaining a pseudo zoomed-up photography by partially trimming a photographed picture at a trimming magnification .beta. which can be previously set, and a control device which sets the trimming magnification .beta. of the trimming photographing device to a maximum trimming magnification .beta.max if the operating device is moved to the zoom-up side when the electric-powered zoom lens is at the position of a maximum focal length FT, which zooms down the electric-powered zoom lens while maintaining the maximum trimming magnification .beta.max if the operating device is thereafter operated to the zoom-down side, and which changes the trimming magnification .beta. of the trimming photographing device from the maximum trimming magnification .beta.

Abstract: A lens barrel having first and second lens groups and first and second tubes. The first tube has first and second guide grooves to respectively guide the first and second groups in an optical direction. The second tube has first and second cam grooves to respectively guide the first and second lens groups, in conjunction with the first and second guide grooves, for focusing and zooming operations. A first collapsing use groove extends substantially perpendicular to the optical axis from an end of the second guide groove that is closer to an image surface to maintain the second lens group in a stationary position on the optical axis when the first lens group is collapsed toward the second lens group and when the first lens group is extended into a wide state.

Abstract: A zoom-type viewfinder device which has a multi-sectioned viewfinder cam which rotates in connection with the zooming of a photographic zoom lens. The viewfinder cam has a cam, with at least one cam bevel, which is divided into a first cam component and a second cam component. The first cam component and the second cam component are joined to connect the respective cam bevels to form a cam bevel which wraps more than once around of the cylinder of the viewfinder cam. As the viewfinder cam is manufactured in multiple segments, each segment can be removed from its forming die in the longitudinal direction of the viewfinder cam, thereby providing smooth zooming and a blur free viewfinder image. Also, the inclinations of cam bevels, which are formed on the viewfinder cam, can be made more gradual, which reduces the required driving force. Therefore, a more compact motor can be used, resulting in a more compact camera.

Abstract: A camera including a mount portion onto which a lens barrel housing a lens is mounted as movable in a direction of an optical axis thereof, a moving mechanism for moving the lens barrel in the direction of the optical axis, a limiter for setting a limit of movement of the lens barrel moved by the moving mechanism while the lens barrel is mounted on the mount portion, and a limit remover for removing the limit of movement set by the limiter when the lens barrel is dismounted from the mount portion. The camera further includes a signal transmission apparatus in which the lens barrel is mounted as movable in the direction of the optical axis thereon on the camera body. The signal transmission apparatus includes a light emitting element located on either one of the lens barrel and the camera body, and a light receiving element located on the other one of the lens barrel and the camera body, for receiving light from the light emitting element.

Abstract: A camera with a built-in flash light unit has a light shielding barrel of truncated cone shape and a stepped film cartridge chamber. The light shielding barrel is disposed to shield an optical path between a photographic lens at a front of the camera and a film plane at a rear of the camera, the smaller end of the truncated cone residing at the photographic lens. The cartridge chamber is provided at one side of the light shielding barrel and encloses a film cartridge having a cylinder for including a film wound therein and a feed step tangentially projecting out from a circumference of the cylinder for film feed therefrom. The cartridge chamber has a predetermined rear-to-front dimension and comprises a first room defined by a curved wall shaped to fit the cylinder and a second room connected to the first room and defined by a wall shaped to fit the feed step. The light shielding barrel and both of the cartridge chamber walls define a space between the cartridge chamber and the light shielding barrel.

Abstract: A device for varying the focal length of a phototaking optical system comprises a cam member having a cam portion, a guide member having a guide portion, a driven member provided in a part of the phototaking optical system and maintained in contact with the cam portion and the guide portion, and a drive unit for moving the driven member in response to a relative movement of the cam member and the guide member, thereby continuously varying the total length of the phototaking optical system between a telephoto end position and a wide angle end position, wherein the cam member is formed by molding of a resinous material in such a manner that a parting line formed in the cam portion is not contacted by the driven member at the telephoto end position and at the wide angle end position.

Abstract: A camera having a hand tremor correction mechanism with improved positioning of the hand tremor correction mechanism. The camera includes a photographic lens which moves along the optical axis of the photographic optical system. A vibration detection unit detects camera vibration, such as from hand tremor, and produces a corresponding output signal. A vibration correction mechanism, coupled to the external periphery of the photographic lens and electrically connected to the vibration detection unit via a flexible printed circuit board, receives the output signal of the vibration detection unit and compensates for the vibration detected by the vibration detection unit.

Abstract: A camera display device includes a display unit which is selectively illuminated during camera operation. The display unit displays information to the photographer such as photometry and rangefinding information. A mode selector switch selects a camera operating mode from a plurality of operating modes and a camera instruction unit outputs an illumination instruction to an illumination light to thereby illuminate the display unit. A timer determines a time period for illumination of the display unit while a control unit continues the illumination of the display unit during a predetermined continuation time period in response to the illumination instruction from the camera instruction unit. The control unit also continues the illumination of the display unit until an end of the camera operating mode selected by the mode selector switch.

Abstract: A camera has an exposure device for effecting a photographing operation on a film in response to manipulation of a member, and a self-timer for causing the exposure device to effect the photographing operation after the counting of a predetermined time. The self-timer has a first state for causing the exposure device to effect the photographing operation only once and a second state for causing the exposure device to effect the photographing operation plural times. The camera comprises a first display for indicating that the self-timer is in an operable state, a second display for indicating that the exposure device functions plural times in response to the manipulation of the number, independently of the self-timer, and a control device for controlling the first and second display. The control device is adapted to only activate the first display in the first state of the self-timer and to activate both the first and second displays in the second state of the self-timer.