Ricoh Company, Ltd.

Yoshimi Ohno

Takayuki Hatase

Ikuya Tsurukawa

Junichi Shinohara

Daisuke Hata

Kazumasa Aoki

Susumu Iguchi

Kenji Koyama

Yoshio Serikawa

Takao Yamaguchi

Tokio Ishino

Tohru Nishida

Hiroshi Takeda

Tatsutoshi Kitajima

Keiji Himuro

Atsushi Satoh

Takashi Hongou

A direct current motor including a rotor having a rotation shaft and rotor coils, a stator configured to apply a magnetic field to the rotor via magnetic poles of the stator opposing magnetic poles of the rotor, an electrical parts mounting base board fixed on the rotation shaft such that the rotation shaft perpendicularly intersects the electrical parts mounting base board, and a commutator having a contact electrode part formed with a plane conductive layer pattern and connected to the rotor coils. The contact electrode part is formed on the electrical parts mounting base board. The direct current motor further includes a pair of electrode brushes in sliding contact with the contact electrode part of the commutator and configured to supply electric power to the rotor coils though the commutator.

DC motor

A direct current motor rotation control apparatus, a method and device for controlling a rotational speed of a direct current motor, and an apparatus having the direct current motor rotation control apparatus. The apparatus and device control rotational operations of a direct current motor such that the direct current motor rotation control apparatus includes at least one rotation detecting brush which detects a signal indicative of an operation of the direct current motor, a motor driving circuit which drives the direct current motor by applying the direct current drive voltage to the pair of electrode brushes, a reference voltage generating device which generates a reference voltage a comparator which compares a voltage detected by the rotation detecting brush with the reference voltage generated by the reference voltage generating device and produces an output comparison voltage, and a motor control circuit which adjusts the direct current drive voltage based on the output comparison voltage. The direct current motor includes including a stator, a rotor with a rotation shaft and rotor coils, a commutator connected to the rotor coils, and a pair of electrode brushes in sliding contact with the commutator. The at least one rotation detecting brush contacts the commutator at a different axial position from an axial position contacted by the pair of electrode brushes. The comparator can compare a voltage detected by the rotation detecting brush with the reference voltage generated by the reference voltage generating device and produces as a comparison voltage output pulses of voltage. As such, the motor control circuit can determine an instantaneous rotational speed and adjust the drive voltage to the pair of electrode brushes accordingly.

DC motor rotation control apparatus

A rotation detector apparatus and a rotation control apparatus for the DC motor is disclosed wherein rotational operations of a rotor of the DC motor are controlled by detecting at least one of the rotational direction, the rotational speed, the cumulative rotation number, and the rotational position of the rotor. The pulsed output signal from at least one motor rotor rotation detector brush is processed by signal processing circuitry to regulate the at least one of the rotational direction, the rotational speed, the cumulative rotation number, and the rotational position of the rotor.

DC motor rotation detecting apparatus and DC motor rotation control apparatus

A direct current motor rotation detecting apparatus and a direct current motor rotation control apparatus detect and control at least one of a rotational direction, a rotational speed, a rotational position, and a cumulative rotation number of a rotor of a direct current motor. The apparatus include at least one rotation detecting brush which detects a rotation of the rotor, a differentiating circuit which differentiates a voltage obtained through the at least one rotation detecting brush, and a pulse generator triggered by the differentiating circuit at a time interval proportional to a rotational speed of the direct current motor to generate pulses having a predetermined pulse width.

A camera which imprints alphanumeric messages on the film. The camera allows a user to view, in the order of most frequently used, the messages which can be imprinted. In order to reduce the cost of the camera, there is a dot matrix LCD display which can only display a limited number of characters which is less than the total number of characters of the largest message. After a user takes a picture, the dot matrix display scrolls through the message which has been imprinted on the film so that the user can confirm that the correct message has been imprinted. The speed at which the characters are scrolled or displayed is determined based on the total number of characters of the message. As an alternative to scrolling, the characters can be displayed one or two at a time. As an alternative, instead of displaying the alpha-numerical characters of the message, a graphical indication is given that some type of information has been imprinted on the film. The duration at which this confirmation of message imprinting is displayed or scrolled corresponds to the length of the message in order to give the user some indication of the message.

Camera which displays information to a user corresponding to a message

A camera having a blurring movement correction mechanism comprising: an optical element disposed in an optical path of a photo-taking optical system so as to correct shift of an image formed on a film surface caused by movement of hands holding a camera body. The camera further comprises: a detection unit for obtaining a blurring movement detection data by converting the blurring movement of the camera body to an electric signal; a calculation circuit for calculating blurring movement correction data for correcting the shift of the image formed on the film surface caused by movement of hands holding the camera body; a blurring movement correction actuator for moving the optical element in a necessary direction for correcting the shift of the image on the film surface on the basis of the blurring movement correction data obtained from the calculation circuit; and a noise removing circuit for removing transition output components included in the blurring movement detection data obtained from the detection unit which components are generated at a time when said blurring movement correction actuator is driven.

Camera having blurring movement correction mechanism

A focus state detection device comprising: a first optical conversional system for forming an optical flux in one of two symmetric regions with respect to an optical axis of an optical flux from a subject to be photographed; a second optical conversional system for forming an optical flux in the other of the two symmetric regions; and a third optical conversional system for forming an optical flux in a region including the optical axis. The device further comprises a first and a second photoelectric converters for generating electric signals in response to optical intensity distribution data of the fluxes formed by the first and second systems, respedtively; a third photoelectric converter for generating an electric signal in response to optical intensity distribution data of the flux formed by the third system; and a calculation unit for detecting a focus state of the subject on the basis of correlation between three electric signals output from the first, second and third converter means.

Focus state detection device

A trimming information recordable camera which is usable in cooperation with a labo-system in which a film is printed according to the trimming information written in the film when loaded in the camera. The camera comprises: a photographing lens raving a plurality of focal lengths and capable of selecting one of the focal lengths; a zoom finder through which a view field angle can be changed; and a system for writing a trimming data in the film. The film is printed in accordance with the trimming data which is obtained from a data of the view field angle of the zoom finder and a data of a view field angle of the photographing lens.

Trimming information recordable camera

A camera having blurring movement correction mechanism comprising: an optical element arranged to correct shift of an image formed on a film surface caused by movement of hands holding a camera body; an actuator for moving the optical element in a necessary direction for correcting the image shift; a detection unit for obtaining a blurring movement detection data by converting the movement of the camera body to an electric signal; a first memory unit for temporarily registering the detection data output from the detection unit; a calculation unit for calculating blurring movement correction data for correcting the image shift caused by movement of the camera body by actuating the optical element by the actuator; and a second memory unit for temporarily registering data of calculation. The correction data is predictively calculated from the detection data of this time obtained from the detection unit, the detection data of the preceding time registered in the first memory unit and the correction data of the preceding time registered in the second memory unit.

In a focusing state detector, a light beam transmitted through a photographing lens is divided into three light beams in three regions through a condenser lens and three converting optical systems. The three light beams are focused and formed as an image on three photoelectric converting portions and are photoelectrically converted to three kinds of electric signals. A correction calculator receives data of an integral time ratio provided by a charge coupled device at a plurality of time points from a correction coefficient calculator. The correction calculator corrects image data obtained by the three photoelectric converting portions by using a correction coefficient according to the integral time ratio. A phase difference calculator receives the corrected image data of the correction calculator and provides phase difference data. The focusing state of a lens system is accurately detected even when a photographed object is moved in a direction perpendicular to an optical axis of the lens system in a plurality of detections of the detecting state and a brightness distribution of the photographed object is changed.

A trimming information recordable camera which is usable in cooperation with a labo-system in which a film is printed according to the trimming information written in the film when loaded in the camera. The camera comprises: a photographing lens having a plurality of focal lengths and capable of selecting one of the focal lengths; a zoom finder through which a view field angle can be changed; and a system for writing a trimming data in the film. The film is printed in accordance with the trimming data which is obtained from a data of the view field angle of the zoom finder and a data of a view field angle of the photographing lens.

A focus detecting device gathers first image data by a couple of linear arrays of photo diodes in a CCD, which are disposed oppositely with respect to an optical axis of an objective, and second image data by a couple of photo diodes arrayed disposed close to one of the photo diode arrays. A CPU calculates a integer part and fractional part of a displacement of first and second images represented by the first image data, and checks if the calculation results are reliable for focus detection, by using the first and second image data. A counter contained in the CPU counts the number of decisions of unreliable. When a count of counter reaches a preset value and when the latest decision of unreliability is made for the integer part calculation result, a subsequent lens drive is prohibited, and the integration by the CCD, and the integer part calculation are repeated, while presenting a display of 'Unmeasurable'. Further, an additional reliability check is made of the result of the latest integer part calculation. If the additional reliability check shows a satisfactory reliability, the CPU goes out of the repetitive operation of the integration and the integer part calculation, and removes the prohibition of the lens drive.

Device and method for detecting a focusing state with reliability

Compensation of a deviation produced in the image forming position of a varifocal lens in consequence of magnification is attained by transforming a compensation amount into a relative amount of movement through arithmetic operation and driving the focusing lens group of the varifocal lens until the actual amount of movement conforms to the value obtained by the transformation.

Varifocal lens device

A variable focal lens device having an optical system comprising a variable power lens group and a focusing lens group disposed on one identical optical axis in which a deviation of a focusing position is resulted with an identical object when the focusing lens group is set at a predetermined focusing position from a nearest position to an infinite position on the optical axis corresponding too an object distance from a nearest distance to an infinite distance and then moving the variable power lens group along the optical axis thereby renewing an entire system focal length of the variable power optical system from a first focal length to a second focal length.

Variable focal lens device

An auto-focus arithmetic device suitable for use in a photographic camera is provided. The device includes a photographic lens which is movable along a predetermined optical axis and a CCD for detecting light coming from a subject of interest through the lens. An arithmetic unit for determining the direction and amount of movement of the lens with respect to the subject of interest based on a detection signal from the CCD is provided. The arithmetic unit includes an integer portion calculating sub-unit for calculating an integer portion of the detection signal and a fractional portion calculating sub-unit for calculating a fractional portion of the detection signal. The fractional portion calculating sub-unit remains deactivated as long as the detected amount of discrepancy from the in-focus condition is larger than a predetermined level; however, it is activated when the detected amount of discrepancy becomes equal to or less than the predetermined level. In this manner, in accordance with the present invention, the integer and fractional portion calculating sub-units are used alternately.

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Kawasaki, Japan

Yoshimi Ohno