摘要:
Very precise indications of the Apex indication values in a camera are displayed through the viewfinder. The nominal value is displayed numerically and further indications are provided to display fractional parts of one step of a nominal Apex indication value.
摘要:
A shutter speed digital display device for cameras equipped with both automatic and manual shutter speed controls is disclosed. A shutter speed display control circuit generates a first digital signal in accordance with the adjustment of the camera's shutter speed by an automatic shutter speed control circuit. The first digital signal is decoded and used to control a light-transmitting liquid crystal device display. In addition, when the camera is in a manual mode of operation, the first digital signal is compared with a second digital signal related to manually adjusted shutter speed. If the comparisons are equal, a coincidence indicator is energized.
摘要:
A method and apparatus for automatic iris control of cameras having an exposure value indicator located within the camera's viewfinder. The indicator emits light such that a photosensor when moving over the indicator face, senses the light and through associated circuitry and mechanisms stops the movement of an adjusting iris.
摘要:
An automatic iris adjustment control for cameras which, using the APEX operational equations, compares the brightness value Bv and film sensitivity value Sv with the iris size indication value Av and shutter speed value Tv. The iris size indicating value Av is derived from the sum of pulses created by a pulse generator which operates in conjunction with the moving adjustment of the iris size. When the values are compared and found equal, an electro-magnet is de-energized stopping the movement of the adjustable iris at the correct iris setting.
摘要:
An apparatus to be used in a camera to digitally indicate inside the viewfinder, film exposure values based upon iris opening, shutter speed and film exposure index.
摘要:
An automatic exposure control circuit for a camera is disclosed. The circuit is capable of automatically controlling the shutter speed when the diaphragm is manually set, and is capable of automatically controlling the diaphragm opening when the shutter speed is manually set. In both cases the same transducer is used for the manual diaphragm or shutter speed selection.
摘要:
An automatic exposure control device is disclosed which is capable of aperture dominant and shutter speed dominant exposure control operation as well as manual exposure control operation. A logarithmic compression circuit including transducers develops voltages directly dependent upon the APEX indicating quantities Bv, Sv, Tv and Av. For automatic operation one of the voltages dependent upon Tv or Av is set into the circuit by manual control, and the other is calculated by the APEX indication formula Bv + Sv = Tv + Av, and applied as an output to the shutter control or aperture control mechanism. An indicator means is connected in the circuit to provide Tv or Av indications depending on the exposure control mode selected for the camera.
摘要:
An automatic exposure control device for a single lens reflex camera characterized in that a stop determining member which stops down diaphragm blades by rotation thereof at a predetermined speed is released by a shutter release plate. A time constant circuit is started to operate simultaneously with the start of rotation of said stop determining member, and the rotation of said stop determining member is stopped by an electromagnetic mechanism when a time has lapsed. The length of said time linearly corresponds to the stop size determined by APEX operation based on the output voltage of said time constant circuit as an operation factor.
摘要:
An exposure display device for a single lens reflex camera including light display elements for displaying either shutter speed or diaphragm value is disclosed. Nominal values representing either shutter speed or diaphragm value are marked on a glass plate disposed in the vicinity of the focusing plate of the camera's viewfinder. A first display section, comprising a first set of light display elements aligned with (and, if desired, located inbetween) the nominal values, creates a first exposure component (e.g. diaphragm value or shutter speed) display whose value is related to predetermined exposure conditions, such as object brightness, film sensitivity and the other exposure component (e.g. shutter speed or diaphragm value). A second display section, comprising a second set of light display elements, also aligned with the nominal values, creates a second display of the exposure component chosen to be displayed. The second display represents the actual position of the camera element controlling the displayed exposure component.
摘要:
A mechanical arrangement is disclosed for blocking the electric shutter operation of a camera when the rear shutter holding electromagnet is not energized sufficiently to hold the rear shutter. A pair of gears for the front and rear shutters, respectively, are mechanically linked to the shutters to prevent their running when the gears are held stationary. A release controlled lever holds the front shutter gear stationary, and the stationary position of the front shutter gear holds the rear shutter gear stationary. When the release button is depressed the front gear is released from the lever and rotates as the front shutter runs to an unblocking position. Rotation of the front gear frees the rear gear, but the rear shutter is held by the electromagnet until the exposure time is completed. Thereafter the electromagnet is deenergized causing the rear shutter to run to its blocking position and the rear shutter gear to rotate. If the electromagnet is not sufficiently strong, e.g. because of a reduction in battery power, to hold the rear shutter, both shutters will start to run and both gears will start to rotate simultaneously. A lever held in a first position by the starting position of the rear shutter gear, moves to a second, blocking position, when the rear shutter gear starts to rotate. When in the blocking position, the lever stops further rotation of the front shutter gear which, in turn, stops further rotation of the rear shutter gear. The operator, as a result, hearing no running sound of the shutters knows there is a failure in the electromagnet circuitry.