Seikosha Co., Ltd.

Other

Mitsubishi Chemical Corporation

Mitsubishi Kasei Corporation

Nissan Motor Company Limited

Seiko Precison Inc.

Michio Kawai

Yoichi Seki

Shinji Nagaoka

Hiroyuki Saito

Koji Sato

Masatoshi Kimura

Akira Ito

Mamoru Nozomi

Katsushige Hayashi

Kanji Ito

Tomihiko Aoyama

Masayuki Nakajima

Tomohiro Yamazaki

Hajime Oda

Kazuo Akimoto

Shinichi Endo

Masae Kubo

Shigeru Tagami

Tadashi Ishikawa

Ryoko Aso

Takahito Otora

Michio Taniwaki

Teruyo Hayakawa

Hiroto Tsuyuki

Motonori Ueda

Youichi Seki

Tadashi Umehara

Osamu Murakami

Mitsuhiro Kakuta

Ryuji Nakayama

Akiko Miyake

Takayuki Sato

Shigenobu Harada

Junji Takano

Hiroshi Takeguchi

Hiroshi Nakano

Aromatic polycarbonate

An aromatic polycarbonate composition which has excellent thermal stability and maintains high transparency and a satisfactory hue even at high temperatures. The aromatic polycarbonate composition comprises: a polycarbonate obtained by reacting at least one aromatic dihydroxy compound with a compound capable of incorporating a carbonate bond; and a phosphorus compound represented by the following formula (1):

Aromatic polycarbonate composition

A large-capacity optical recording medium, comprises

Optical recording medium having zones wherein the number of sectors per

The disclosure describes a flame-retardant polyester resin composition comprising: (1) 100 parts by weight of a polyester resin which may contain a halogen atom;

Flame-retardant polyester resin composition

A distance measuring device for ensuring accuracy of the positional relationship between the optical axis of a light-receiving lens and the optical center of a light-receiving element obtains distance information data by measuring the distance to a target plate which is 1 meter from the distance measuring device. If the distance information is not smaller than 1.625 meter, a switch is connected to one pair of terminals and the difference between reference output data stored in a control circuit and output data of an AF-IC obtained when the distance to the target plate is measured with the switch connected to the pair of terminals is calculated and stored in a memory circuit. When the value of the distance information data is not greater than 0.375 meter, the switch is connected to another pair of terminals, and output deviation data is stored in the memory circuit 11 in the same way. When the value of the distance information value is smaller than 1.625 meter and greater than 0.375 meter, the switch is connected to a further pair of terminals, and output deviation data is stored in the memory circuit in the same way.

Distance measuring device

A distance measuring apparatus for a camera comprises a light projecting device for projecting light to an object to be photographed, a light receiving circuit for receiving light projected by the light projecting device and reflected by the object to be photographed and for converting the reflected light into first and second output signals, a first selecting device for selecting the first output signal, and a second selecting device for selecting one of the first and second output signals. A first signal processing circuit is connected to the first selecting device for processing the output signal selected by the first selecting device. A second signal processing circuit is connected to the second selecting device for processing the output signal selected by the second selecting device. A first memory stores output signals of the first and second signal processing circuits, the output signals being generated upon operation of the light projecting device when the first selecting device selects the first output signal and the second selecting device selects the second output signal. A second memory stores output signals of the first and second signal processing circuits, the output signals being generated upon operation of the light projecting device when the first and the second selecting devices both select the first output signal. A calculation circuit calculates a distance to the object to be photographed by adjusting an output of the first memory by an output of the second memory.

Distance measuring apparatus for a camera

A distance measuring device for a camera has a near infrared light-projecting element for projecting measuring light to be reflected by an object to be photographed. The reflected measuring light is received as a first light beam image at a first position on a surface of a first light-receiving element. The reflected measuring light reflected by the object is also received as a second light beam image at a second position on a surface of a second light-receiving element. A CPU controls the focusing movement of the lens of the camera by computing a distance to the object depending on the first position, compensating the computed distance depending on the second position, and controlling the focusing movement of the lens based on the compensated computed distance. The CPU compares the second position with a predetermined distance value and inhibits the compensation of the computed distance if it is determined that compensation is not necessary.

Distance measuring device for a camera

Disclosed herein is an electrophotographic photoconductor comprising:

Polycarbonate binder resin and electrophotographic photoconductor

A photographic camera has a rectilinear approximate operation circuit for calculating characteristic correction data for correcting errors in the operational characteristics of the camera. Predetermined theoretical characteristic data dependent on operational characteristics of the camera are stored. Measured data corresponding to predetermined measured values are stored as individually measured characteristic data in a nonvolatile EEPROM so that the stored measured data can be easily changed by rewriting the EEPROM. An object signal is generated depending on an object to be photographed. The rectilinear approximate operational circuit calculates characteristic correction data from the object signal, the theoretical characteristic data and the measured characteristic data, which is then used for correcting errors in the operation characteristics of the camera.

Device for correcting characteristic errors of a camera

In a step-up circuit for causing the emission of light of a distance measuring light emitting element, the step-up circuit outputs a step-up voltage from one terminal of a step-up capacitor. A step-up voltage level changeover circuit applies a step-up voltage to the capacitor every time the distance measuring light emitting element emits light that is higher than the step-up voltage in the normal state. The number of parts is reduced by eliminating a separate capacitor for light emission, the space for the circuit is reduced by using the capacitor having a small capacity, the soldering steps for fabrication of the circuit are automated; and the costs for assembly are ameliorated owing to the automation.

Power supply circuit for driving a light emitting element

A novel electrophotographic photoreceptor and a method of preparation therof are disclosed. The photoreceptor is characterized in that the photosensitive layer contain a specific carbonate resin binder resin having a weight average molecular weight on not less than 200,000. The resin is preferably a polycarbonate resin which contains repeating units represented by the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are respectively and independently a hydrogen atom, a lower alkyl group, a halogen atom or an unsubstituted or substituted aromatic group; and R.sup.9 and R.sup.10 are respectively and independently a hydrogen atom, a lower alkyl group, an unsubstituted or substituted aromatic group, or form a ring or a carbonyl group together with the linking carbon atom. The method is characterized in that the photosensitive layer contains a polyocarbonate having a weight average molecular weight of not less than 200,000 as a binder resin and is formed by spray coating or spiral coating.

Electrophotographic photoreceptor containing polycarbonate resin as a

An auto focus camera produces a distance signal representative of the distance from the camera to an object being photographed. A first storage circuit stores comparative data to be compared with the distance signal, and a comparator circuit compares the distance signal with the comparative data. A second storage circuit stores lens extension amounts corresponding to the comparative data stored in the first storage circuit and outputs a lens extension amount corresponding to the specific comparative data selected by the comparator circuit. A focusing lens is positioned according to the output from the second storage circuit.

Auto focus camera

An auto-focusing device includes a light emitting element for emitting an optical beam to be projected upon an object, an image position detecting element for receiving the optical beam reflected from the object for outputting an image position signal, and range computing circuitry for receiving the image position signal and computing therefrom the range to the object and outputting a corresponding range signal. First and second level deciding circuits decide whether or not the computed data based on the image position signal is at a level validating the computation of the range signal. The level deciding circuits output a remotest or nearer-than-remotest signal dependent upon the computed image position signal if the computed data from the image position signal is not validated. A lens position setting device sets a lens position from either the range signal, the remotest signal or the nearer-than-remotest signal in accordance with the decisions of the first and second level deciding circuits.

Autofocusing device with improved distance focusing accuracy

An analog-to-digital converter for a camera has a reference signal generating element, a measurement signal generating element, and pulse output means for generating pulses of pule durations corresponding respectively to signals from the generating elements. The generating elements are alternately selected to produce two pulse durations, and the ratio of these two durations is computed by pulse duration ratio computing means. Control information corresponding to the computed ratio is retrieved from memory means.

Analog-to-digital converter for camera

An active rangefinder for use in a camera. The rangefinder has a light-emitting device, a spot light position detector disposed at a given distance from the light-emitting device, head amplifiers, filters having amplification function, synchronous detectors, integrators, an adder, a subtracter, a microcomputer, and an automatic gain control (AGC). The filters are connected to their respective head amplifiers each having an operational amplifier. The gains of the filters are controlled by the AGC according to the output signals from the synchronous detectors.

Rangefinder for camera

Growing community of inventors

Yotsukaido, Japan

Michio Kawai