Abstract: An automatic focus detecting and indicating device for an camera in which a contrast signal is coupled through first and second analog switches directly to a difference circuit and through a peak hold circuit, respectively. A third analog switch is coupled so as to discharge the value stored in the peak hold circuit. The three switches are operated by a control circuit which in turn operates in accordance with the direction of movement of the lens and the detection of a rising edge of the contrast signal so as to prevent the generation of a false focus signal at other than the point of true focus.

Abstract: A light-shielding device for a single lens reflex automatic focus camera in which the focus detecting element is normally covered by a shielding plate. The protecting plate is coupled along one edge thereof to a shaft while the end is coupled to one end of an operating lever. The other end of the operating lever is coupled through a U-shaped spring to a mirror operating lever of the camera wherein the U-shaped spring provides a snap action upon release of the shutter curtain which quickly moves the shielding plate to its uncovered position.

Abstract: A display device for a camera in which both an electrical focus detecting and indicating device and an exposure meter or automatic exposure control device are incorporated into a single display element provided in the view finder of the camera. Switching means is coupled to receive on input contacts thereof signals representing both a focus indication and a shutter speed. Normally, the display device displays information in response to the focus detection and indication signal. When the shutter button of the camera is depressed to a first position, the switching means is changed over to display the shutter speed. The display device may be implemented either by an array of LED display elements or a liquid crystal display element.

Abstract: A focus position indicating device for a camera including an array of electrically activatable display elements such as light emitting diodes or liquid crystal elements, the number of which are activated being dependent upon the state of focusing. A drive contrast signal is converted into a digital signal and compared with the count output of a continuously-cycling digital counter. The output of the counter is also decoded into a set of signals one of which is activated for each possible state of the counter output. The decoder output signals are gated by the output of a comparator circuit with the outputs of the gates connected to drive the display elements.

Abstract: A focusing system for a camera using an array of photoelectric elements to sense the level of light at points in the image plane of an objective lens. The output of the elements are scanned in sequence to form a train of pulses whose amplitudes correspond to the level of light at the respective elements as they are scanned. The pulse train is split into two pulse trains of alternate pulses. The two pulse trains are separately converted to two analog signals and applied to a differential amplifier. The difference output is clamped to a reference potential and applied to a peak detector. When the objective is in focus, the output of the peak detector is at a maximum.

Abstract: An automatic focus detecting device for a camera including a self-scanning type photoelectric conversion element array. The array is operated in two modes, a brightness detecting mode and a focus detecting mode. In the brightness detecting mode, the individual light detecting elements are connected in parallel with one another and to a brightness detection module. Once the brightness detection has been made, the scanning frequency of the array is set in accordance with the brightness value detected. The photodiode elements are then coupled in serial fashion to a focus detecting module. The position of the lens is varied until the focus detecting module indicates that the proper focalization position has been reached.

Abstract: An automatic focus detecting device for a camera in which a self-scanning photoelectric element array is scanned at a rate depending upon the average amount of light reflected from an object being photographed so that accurate focus detection is maintained over a wide range of illumination conditions. An average illumination detecting element is disposed at a position near or at a position optically equivalent to that of the microphotoelectric elements of the element array. A low-pass filter couples the output of the average illumination detecting element to a clock pulse generator which produces clock pulse signals of which the frequency varies according to the smoothed output signal from the low-pass filter representing the average illumination. As the brightness of the object increases the frequency of the clock pulse signal correspondingly increases to compensate for variations in brightness of the object.

Abstract: A camera including an automatic focalizing device with which the camera will automatically focus only upon objects within a predetermined range set by the photographer. The wiper of a potentiometer is coupled to the lens so that its operative position is determined by the position of the lens. The wiper is also electrically coupled to respective positive and negative comparison inputs of first and second comparators to the other inputs of which are applied voltages from a second potentiometer which are determinative of the selected range at which focalization may be achieved. The combined outputs of the comparators are coupled to the control input of an analog switch device coupled between the output of a focus detector and the control circuit of a lens positioning motor.

Abstract: A device for detecting and indicating the focus position of a camera from the contrast signal. A peak value detector holds the maximum value of a contrast signal produced in the camera. The stored signal is compared with the contrast signal itself as the direction of the lens is reversed and the focus signal is generated when the two signals are equal. The values stored in the peak detecting circuit is reset as the shutter button is pushed as the lens commences movement in the forward direction to prevent erroneous generation of the focus signal.

Abstract: A focus indicating device in a camera employing a photoelectric transducer for scanning the image of an object to output a time series signal equivalent to the brightness distribution of the image. A contrast detection circuit extracts a power spectrum in a high spatial frequency range which becomes a contrast signal of the image. An indication meter indicates the contrast signal directly in the view finder of the camera with the deflection angle indicating a maximum value when proper focus is obtained.

Abstract: A focalization detecting device in a camera utilizing a self-scanning type photoelectric device having a number of elements disposed at a position equivalent to the position of the image forming plane of a lens. A drive circuit drives the photoelectric element and a delay circuit delays a discrete output waveform of the photoelectric element the time corresponding to the scanning period of one or two elements. A difference circuit detects an output difference between the delayed waveform and the undelayed waveform. An absolute value circuit detects the absolute value of a difference output from the difference circuit and a peak value holding circuit holds a peak value in an absolute value waveform provided by the absolute value circuit in one scanning period of the photoelectric element, in such a manner that an output difference between said element is detected with a discrete photoelectric transducing output as it is. The maximum peak value output is provided when focus is obtained.

Abstract: An automatic focus detecting device for a camera including a self-scanning type photoelectric element unit including plural minute photoelectric elements disposed in a plane corresponding to the position of the image forming plane of the photographing lens of the camera. The photoelectric element unit is scanned and the output signals from the unit are sampled and held over a scanning time period. The output signals from second adjacent ones of the elements are coupled to differential circuits the outputs of which are multiplexed onto a single output line. The peak value of the multiplexed signal is detected. When the peak value signal is at its maximum, the camera will be in proper focus.