Asahi Kogaku Kogyo Kabushiki Kaisha

Masao Jyojiki

Kazuo Nakamura

Seijiro Tokutomi

Harumi Aoki

Ryota Ogawa

Satoru Tachihara

Michiro Ohishi

Naoyuki Uno

Koichiro Watanabe

A positioning apparatus of an optical element in the form of a thin film includes at least one positioning element having a surface opposed to the optical element without contacting the same, together with a mechanism for moving at least one of the optical element or the positioning element, in a direction parallel to a plane of the thin film. The opposed surface of the positioning element produces a fluid force when relative movement between the optical element and the opposed surface of the positioning element occurs and serves to hold the thin film at a predetermined position. An optical scanner incorporating such a positioning apparatus is also disclosed.

Positioning apparatus for an optical element in the form of a thin film

A camera including an electronic focus detecting device and an optical display device for indicating whether the photographing lens of the camera is at a rear focus position, a front focus position or a correct focus position and for indicating whether the lens is being moved in the correct direction towards the position of correct focus. First and second photoelectric conversion element arrays are disposed in front of and behind a position which is optically equivalent to the position of the film surface in the camera. Signals are produced from the respective outputs of the arrays which are in proportion to the degree of focus than existing. A different signal is produced as well and the three signals are then processed to determine the indicated positions in a disclosed circuit arrangement.

Focus detecting and indicating device for camera

A focus detecting device having two concave mirrors for reforming the image of an object which is formed between a lens and the focal plane of lens, and for dividing said image two same secondary images. Two light receiving element arrays are provided in the image forming planes of the secondary images. A signal processing circuit subjects the outputs of the light receiving element arrays to produce a signal indicating whether or not the lens is focussed on the object. By means of the two concave mirrors adapted to form said secondary images, the two secondary images are shifted in the opposite directions on the light receiving element arrays at the time of defocussing so that the difference between the outputs of the two light receiving element arrays is not zero. At the time of proper focus the two secondary images are located at equivalent positions on said light receiving element arrays so that the difference between the outputs of the two light receiving element arrays is zero. A signal processing circuit produces a signal indicating the establishment of the proper focus.

Focus detecting device

An automatic focus detecting device for a camera adapted to be miniaturized and provided in the form of an integrated circuit. Two arrays of light receiving elements or sensors are disposed in two planes parallel to the surface of the film in the camera on either side of the image plane. The output signals from the sensors are processed in a disclosed electronic circuit to detect desired focus conditions such as front focus, proper focus and rear focus for automatically moving the photographing lens to the position of proper focus.

Camera focus detecting device

A focus detecting device for a camera in which at least first and second groups of light receiving elements are disposed in planes parallel to each other and to the plane of the film in the camera. The absolute values of the difference between the signals from adjacent elements in each group are summed from which is determined the amount of high frequency components in the frequency spectrum of the image being photographed. From this, a processing circuit produces a signal representative of correct focalization when the amounts of the high frequency components are higher than a predetermined level and are equal to each other.

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.

Display device for focus detecting and indicating device for camera

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.

A focus detecting device for a lens system having a subsystem for dividing the image of an object into two optically equal images and for shifting the two images of the object in the opposite directions or shifting only one of the two images of the object. Two photoelectric conversion element groups are adapted to convert the variations in relative position of the two images of the object into electrical signals. An optical system projects the images of the object onto the two photoelectric conversion element groups, in which the following outputs are obtained from the outputs of photoelectric conversion elements forming the two photoelectric conversion element groups by using a calculating circuit: ##EQU1## where: n is the number of photoelectric conversion elements forming each photoelectric conversion element group, m is the number in order of a photoelectric conversion element and, i.sub.1 through i.sub.n and i'.sub.1 through i'.sub.n are the outputs of photoelectric conversion elements which are proportional to the quantities of light applied thereto, respectively.

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.

Electrically operated automatic focalizing camera

A focus detecting device in a single lens reflex camera having a lens system and an optical image splitter for splitting an object image into various partial images disposed at a position optically equivalent to that of a film surface in said single lens reflex camera. An array of photo-electric conversion devices are arranged into at least two rows, each row having a plurality of photo-electric conversion elements. The rows are disposed symmetrically with respect to a center line. The device includes an image projecting device for projecting the partial images onto the photo-electric conversion arrays. The projecting device has an optical axis which optically corresponds to said center line, the output of said conversion array defined by ##EQU1## The output of the conversion array has a maximum value when proper focus is obtained. In the equation: n is the number of said photo-electric conversion elements, p is the parameter of the mutual positional relationship of said photo-electric conversion elements for obtaining output difference, m is the element number of said photo-electric conversion elements, i and i' are outputs corresponding to incident light quantities of photo-electric conversion elements in said rows, and l is an integer defined by 1.ltoreq.l.ltoreq.(n-1) and in the range of p.

Focus detecting device in single lens reflex camera

A focus detecting device having a release lens for reforming the image of an object which is formed between a lens and the focal plane of the lens. A mirror is provided between the release lens and an image reforming plane for dividing the primary image into two secondary images. Two light receiving element arrays provided in the image forming planes of said secondary images provide outputs to a signal processing circuit for comparison to produce a signal indicating whether or not the lens is focussed on the object. The mirror for dividing the primary image into two secondary images, shifts the two secondary images in opposite directions on the light receiving element arrays at the time of defocussing so that the difference between the outputs of said two light receiving element arrays is not zero. At the time of focussing, the two secondary images are located at equivalent positions on the light receiving element arrays so that the difference between the outputs of said two light receiving element arrays is zero.

A focus detection optical system where the image of an object is divided into two images thereof, and the two images are shifted in the opposite directions or one of the two images is shifted. The two images are projected respectively onto two photoelectric conversion element groups adapted to convert the variations in relative position of the two images into electrical signals. A focus detecting device comprises: a calculating circuit for providing outputs V.sub.out1(m), V.sub.out2(m) and V.sub.out3(m) from the outputs of photoelectric conversion elements forming the photoelectric conversion element groups,

A focus detecting device in a camera having an optical member or an optical system for obtaining two images from an object and an optical member for displacing said two images in opposite directions or displacing one of said two images. Two minute photoelectric conversion element groups are used for converting variations in light quantity of portions of the object into electrical signals. A photographing lens projects the image of the object onto the minute photoelectric conversion element groups. A circuit calculates outputs ##EQU1## from the outputs of minute photoelectric conversion elements forming the minute photoelectric conversion element groups. A circuit which has a first calculation function for calculating V.sub.out-3 =V.sub.out-1 +V.sub.out-2 and a second calculation function for calculating V.sub.out-4 =V.sub.out-1 -V.sub.out-2 so that when V.sub.out-3 becomes higher than a predetermined value, different outputs are produced under conditions that V.sub.out-4 &gt;.epsilon..sub.1, .epsilon..sub.1 .gtoreq.V.sub.out-4 .gtoreq. .epsilon..sub.2, and .epsilon..sub.2 &gt;V.sub.out-4. A display produces different displays according to the different outputs where n is the number of the minute photoelectric conversion elements forming each of the two minute photoelectric conversion element groups, m is a number of a minute photoelectric conversion element, i is the output of a minute photoelectric conversion element in one of the two minute photoelectric conversion element groups, i' is the output of a minute photoelectric conversion element in the other minute photoelectric conversion element group, .epsilon..sub.1 and .epsilon..sub.2 are predetermined constants.

A single lens reflex camera including an objective having an optical axis for focusing an image of an object and a device for determining when the objective has properly focused an image at an image plane which is located at a position which is optically equivalent to the location of the film plane, the latter including an image-forming device including a first refracting device for receiving an image from the objective and for providing at least a pair of identical images of the object to be photographed at the image plane, a detecting plane provided along the optical axis having a pair of identical photosensitive detectors, each of which provides an output which varies as the image is moved longitudinally therealong and an image-transmitting device situated at least in part at the image plane which includes a second refracting device for receiving the images from a first refracting device and for participating in the transmission thereof to the detecting plane in a manner according to which the identical images simultaneously move equally in opposite directions along the pair of detectors in response to adjustment of the objective.

Camera having a focusing device

A focus detecting device is disclosed for use in a photographic camera. The device includes two rows of photoelectric focus detecting elements juxtaposed on a substrate in a symmetrical relationship with respect to the center line between both rows of focus detecting elements and arranged to receive light reflected from an object to be photographed through an optical focussing lens system. One row of the focus detecting elements are connected to a dc power source through individual electrical switching elements having their gates coupled to the corresponding outputs of a first trigger pulse generator for generating a train of sequential trigger pulses and through a first common load resistor. Likewise, the other row of the focus detecting elements are connected to the dc power source through individual electrical switching elements having their gates coupled to the corresponding outputs of a second trigger pulse generator for generating a train of sequential trigger pulses synchronized with, or delayed or advanced by a predetermined time interval to, the trigger pulse train from the first generator and through a second common load resistor. The common connection of the first resistor to the one row of the detecting elements and the common connection of the second resistor to the other row of the detecting elements are connected to the corresponding inputs of a comparator. Thus, the focus condition of the object on both the rows of focus detecting elements is detected in accordance with an output from the comparator based on the upper-lower image coincidence method and/or the contrast method.

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Tsurugashima, Japan

Masao Jyojiki