Minolta Camera Kabushiki Kaisha

Yasuhiro Nanba

Seiji Yamada

Motonobu Matsuda

Kayoshi Tsujimoto

Hiroshi Ueda

Masayoshi Sahara

Toshio Kobori

Mitsuru Saito

Yoshio Kuramoto

Nobuyuki Taniguchi

Toshihiko Karasaki

Yoshihiro Tanaka

Toru Matsui

Toshinori Imura

Mashio Kitaura

Shigehiro Miyatake

Jun Hasegawa

Eiji Yamakawa

Kenji Takada

Tohru Matsui

Norio Beppu

Takayuki Gotoh

An image sensing device that outputs a signal logarithmically proportional to the intensity of the incident light. The image sensing device makes use of a sub-threshold current flowing between the drain and source of a MOS transistor when the gate voltage is below the threshold voltage (above which the MOS transistor is nominally conductive and below which nominally non-conductive). Since the logarithmic conversion is done in the photosensing section of a solid-state image sensing device, the output from the device is already compressed and is easily handled by a small capacity CCD. Some output systems for the image sensing device of the present invention are also described.

Solid-state image sensing device providing a logarithmically

A focus detecting photoelectric device includes a plurality of photodiodes each formed by an amorphous silicon layer sandwiched between transparent and non-transparent electrodes. The photodiodes are provided in pairs and are aligned in an array and deposited on a glass plate such that the transparent electrode is directly mounted on the glass plate. The photodiodes in a pair are located closely adjacent to, but in a spaced relation with, each other and are electrically connected in series to each other. An image formed on the photodiodes in a pair effects the generation of photocurrent from the photodiodes such that the photocurrents from both photodiodes are approximately the same when the image is out of focus, and they vary from each other as the image becomes sharp.

Focus detecting photoelectric device and focus detecting system

A distance measuring device includes light emitting diode for emitting light toward a subject to be photographed, and a pair of light receiving elements spaced by a predetermined base length from the light receiving diode. The light receiving elements are position side-by-side such that the boundary therebetween extends in a direction which is perpendicular to the direction of the base length so that an image formed by the light emitted to, and reflected from, the subject, will be formed on the light receiving elements in a bridged manner. The respective areas on the light receiving elements occupied by the image differ relative to the distance to the subject. A ratio between the signal levels obtained from the light receiving elements is calculated as a signal representing the distance to the subject.

Distance measuring device for use in a camera

A photographic camera having an automatic rangefinder system wherein a light emitter projects a beam of light through a convergent lens to illuminate a target object. This beam of light is detected through another convergent lens by one of a group of photoresponsive elements forming a light receiver. Depending upon which photoresponsive element of the light receiver detects the reflected beam of light, the range of the target object to be photographed from the photographic camera is indicated. The light emitter and the light receiver are supported by a single support member in laterally offset relation to each other and the lens elements for converging the projected beam of light and the reflected beam of light, respectively, are integrally formed of a synthetic resin. The rangefinder elements are assembled into a rangefinder module.

Automatic rangefinder system for photographic camera with light emitting

This invention is directed to a rangefinding system which includes a light beam source, a plurality of light receiving elements disposed to receive an image light spot reflected from a target object existing in any one of a group of distance zones in such manner that the image light spot is projected on one or more of the light receiving elements, the light receiving elements being adapted to produce a combination of outputs, the contents of which vary depending on the distance between the target object and the rangefinding system the invention also includes a logic circuit for producing signals indicating the distance zone in which the target object exists, the signal generated in response to the combination of outputs, so that the space occupied by the light receiving elements can be advantageously decreased and the precision of rangefinding can be improved.

Rangefinding system

A photoelectric rangefinder for use in a photographic camera for automatically focusing an image of a target object on a predetermined image plane. The system utilizes an electro-optical spatial filter having at least two photoresponsive elements to find the difference in phase between output signals from the respective photoresponsive elements. A signal indicative of the difference in phase between the output signals from the photoresponsive elements is used to move a phototaking objective lens along its optical path to reposition the objective lens in search for a true focus setting. The objective lens is brought into proper focus when the signal indicative of the phase difference assumes a predetermined electric relation with an electric signal indicative of the position of the objective lens along its optical axis.

Photoelectric rangefinder

A camera is equipped with a member bearing data to be photographed such as a date and the like and a data light focusing optical system for projecting the illuminated data from the data member at the front of the camera rearwardly with the object light toward the data photographing portion of the film. The data light focusing optical system is arranged so that the data light is directed to be incident on the data photographing portion of the film from a direction different from the incident direction of the object light. Provided in the front of the data photographing portion of the film is an object light incidence limiting member which is positioned parallel with the plane of the film and allows the transmission of the data light therethrough but interrupts the object light directed toward the data light focusing portion of the film.

Data photographic device for camera

In a photographic camera capable of programmed automatic exposure control, circuitry is provided for also enabling exposure time-preferred automatic diaphragm control and diaphragm-preferred automatic exposure time control. The diaphragm is settable to an initial aperture size, which may be the fully opened aperture, and is capable of being changed to different aperture sizes. A first signal is generated in accordance with the logarithm of the light intensity measured through the diaphragm. A second signal is generated in accordance with a manual exposure time setting circuit. A third signal intermediate the first and second signals is generated with a predetermined ratio between the difference of the first and third signals with respect to the difference between the third and second signals. The diaphragm is set by determining the difference from the initial aperture size to the aperture size to be set in accordance with either the difference between the first and third signals or the difference between the third and second signals with the diaphragm at its initial aperture size. The exposure time is controlled commensurate with the diaphragm aperture set by the diaphragm aperture setting mechanism. An indicator indicates the F-number or exposure time, respectively, in accordance with the mode of operation.

Programmed automatic exposure control circuitry

Dating information is applied to camera film from date information displaying circuitry which receives decoded electronic time signals generated by a chronometer. A first power source energizes the chronometer and a second power source energizes the decoder and display circuitry and other components such as the exposure control circuit. A monitor is provided to enable the camera operator to observe the date information. Manually operable switches are provided to independently actuate the dating apparatus and the exposure control circuit as well as to independently operate the display circuitry and the monitor. In a modified embodiment, logic and switching circuitry are provided to monitor and date either exposure data obtained from a light measuring circuit and analog/digital converter or the date information generated by the chronometer. A manually independently operable switch for actuating the display circuitry is ganged with the switching circuit to expose the date information on the film. Another switch ganged with the switching circuit enables the date information to be monitored. The display circuitry includes switches enabling the date information to be monitored independently of dating the film. One switch is actuated in timed relation with the shutter operation and manual closure of a second switch and opening of a third switch effects dating of the camera film.

Apparatus for dating camera film

An exposure indicating device for use in a photographic camera which includes a light measuring circuit for generating an output representative of scene brightness, a reference voltage circuit for producing reference voltage, a first switching circuit and a second switching circuit receiving the outputs of the light measuring and reference voltage circuits, and indicating means responsive to outputs of the first and second switching circuits. The indicating device indicates that automatically controlled exposure factor, i.e., shutter speed or diaphragm aperture, will be higher or lower with respect to more than one standards, without any change-over of switches. For example, this device indicates that shutter speed to be effected automatically will be in any of blur occurring range, available range and upper outside range.

Exposure indicating device

An exposure control device for a photographic camera uses a conventional exchangeable lens and achieves a highly accurate exposure control commensurate with a pre-selected shutter speed by a light measuring device measuring scene light transmitted through the objective lens, diaphragm, and exchangeable lens. The device also permits exposure control commensurate with a pre-adjusted diaphragm aperture by storing the output from the light measuring device determined with the adjusted diaphragm aperture to control the shutter speed. However, when the device controls the exposure with a pre-selected shutter speed, the output from the light measuring device produced with a fully open diaphragm aperture is compared with the output produced commensurate with the pre-selected shutter speed to thereby control the diaphragm aperture in shifting from its open position to its closed position, and then stores the output from the light measuring device with the adjusted diaphragm aperture to thereby control the shutter speed.

Exposure control devices for photographic cameras

A control device for controlling the exposure time automatically for an electric shutter, in a single reflex camera of the so-called 'through the lens' photometric type which determines the brightness of an object by means of the light past through the projection lens of a camera.

Exposure time control device for an electric shutter in a single reflex

A focus detecting photoelectric device herein disclosed is usable in a focus control system and is placed on an image plane where an optical image of a subject to be, for example, photographed through an objective lens assembly is focused to detect whether the image has been exactly focused or whether the image is out of focus. An output signal from the photoelectric device herein disclosed is used to control the focus control system to effect the desired focus control in relation to the objective lens assembly. To this end, the focus detecting photoelectric device is composed of at least one group of photoelectric elements, such as photodiodes, connected in series to each other with the cathode of one photoelectric element connected to the anode of the other photoelectric element. These photoelectric elements of the group may be formed on a semiconductor substrate in a predetermined pattern by the use of a known IC circuit making technique.

Focus detecting photoelectric device

In an exposure meter having a row of lighting elements, such as lamps or light-emitting diodes, which correspond to respective exposure values, an improvement is made in that by utilizing a capacitor-charging integrating circuit, a constant current circuit and a ring-counter, an exposure value between two neighboring steps of the above-mentioned exposure values can be indicated by lighting said two lighting elements, and in that ranges of exposure indication can be switched by shifting a dial plate, which is facing the lighting elements, in interlocking relation with a range-shifting switch for switching its circuit for range selection, thus enabling a doubling of the steps of exposure values to be indicated with a limited number of lighting elements.

Digital exposure meter

An automatic focus control device has an optical system including an image scanner. The image scanner is disposed between a range-finding lens and at least one light receptor element and on the path of travel of the incoming light towards the light receptor element through the range-finding lens. A mechanism is also disclosed for simultaneously measuring the object-to-lens distance and detecting the contrast of an image of the object projected on the scanner merely by moving the scanner in a direction diverging from the optical axis while a parallel relation between the plane of the scanner and the plane perpendicular to the optical axis is retained.

Growing community of inventors

Sakai, Japan

Yasuhiro Nanba