Ricoh Company, Ltd.

Ikuya Tsurukawa

Yoshimi Ohno

Kenji Koyama

Kunihisa Yamaguchi

Junichi Shinohara

Kosaku Sawabe

Saburo Sasaki

Hiroshi Terui

Kohichi Nishi

Tokio Ishino

Katsuhiko Nuno

Kaoru Ito

Kouji Yokoyama

Akihiro Etoh

Akemi Miyoshi

Takashi Hongo

Provided is a lens barrel configured to avoid deviation of a retracting lens holder frame and a retracting lens holder frame driving member from regular position. Also provided are a camera, a portable information terminal device, and an image input device, all of which use this lens barrel. With the above devices, even when normal cam engagement is damaged by occurrence of drop impact or the like, it is possible to secure normal driving of the retracting lens holder frame and to reduce malfunction of the retracting lens holder frame.

Lens barrel, camera, portable information terminal device, and image input device

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 lens barrel, including, a moving frame () to hold a lens (), a direct-advance ring () provided on an outer periphery of the moving frame and movable relative to the moving frame in an optical direction, a resilient member () provided between the moving frame and the direct-advance ring, and a control part () provided on the moving frame to control an amount of movement of the direct-advance ring in the optical direction.

Lens barrel

A contact structure having a spring with electro conductivity. The spring is fixed at one inner end side of a battery housing by engaging a plurality of inflection parts of the spring to one end side of the battery housing. The spring urges the battery to the other end side of a battery housing. An end portion on movable side end of the spring is extended toward an opening on a lateral face of the battery housing. The end portion is formed on a contact side end of the spring that is contacted with the battery, and is connected to one end side of a bypassing lead wire. An end portion on the fixed side end of the spring is connected to the other end side of the bypassing lead wire. The end portion of the fixed side end of the spring is connected to a power source lead wire. A free end of the contact movable side end can be bent away from the battery to provide a solder connection to the bypass wire.

Resilient contact structure with bypass wire and camera having such contact

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.

In a zoom lens device of a two-lens group structure, positive and negative lens groups are sequentially arranged from a photographing field side. The zoom lens device has a controller for controlling a rear focusing operation for moving the negative lens group on a high magnification side. The controller also controls one of an entire drawing-out focusing operation for moving the positive and negative lens groups, and a front focusing operation for moving the positive lens group on a low magnification side. The high and low magnification sides are respectively set to telescopic and wide angle sides. A focal length of the zoom lens device is increased on the high magnification side and is decreased on the low magnification side. Thus, a zoom ratio is increased and a lens drawing-out amount is reduced on the telescopic side so that the zoom lens device can be made compact. A driving device of a varifocal lens having a two-lens group structure has a base frame and a rear group holding frame for respectively holding front and rear lens groups and moved in accordance with zooming and focusing control states of the varifocal lens.

Zoom lens device of two-lens group structure and driving device of

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

In a zoom lens device of a two-lens group structure, positive and negative lens groups are sequentially arranged from a photographing field side. The zoom lens device has a controller for controlling a rear focusing operation for moving the negative lens group on a high magnification side. The controller also controls one of an entire drawing-out focusing operation for moving the positive and negative lens groups, and a front focusing operation for moving the positive lens group on a low magnification side. The high and low magnification sides are respectively set to telescopic and wide angle sides. A focal length of the zoom lens device is increased on the high magnification side and is decreased on the low magnification side. Thus, a zoom ratio is increased and a lens drawing-out amount is reduced on the telescopic side so that the zoom lens device can be made compact.

Zoom lens apparatus of two-lens group structure

An apparatus for driving a photographic zoom lens in which at least a first and second lens group are disposed on the same optical axis and wherein the apparatus makes it possible to rapidly perform a zooming operation for changing a focal length of the photographic zoom lens. The apparatus comprises a fixed frame and a body tube frame supported within the fixed frame so as to be capable of moving along the optical axis. The apparatus further comprises a first group frame supporting a first lens group, a zooming cam, and a second group frame fixedly supporting a second lens group. Additionally, the apparatus includes a first group driving screw having a first multiple thread screw on a circumferential surface thereof, and adapted to be driven through a first group driving gear and a transmission gear; and a body tube frame driving screw having a second multiple thread screw, and adapted to be driven through a body tube frame driving gear and the transmission gear. The apparatus of the present invention makes it possible to rapidly perform a zooming operation and a housing operation when the power of a driving source and the radius of a driving screw are fixed.

Apparatus for driving varifocal lens

An apparatus for preventing static electricity of a plastic lens has the plastic lens coated with a transparent conductive coating; and a conductive member for electrically connecting the coating of the plastic lens to an electric circuit within a camera such that static electricity of the plastic lens is guided to the electric circuit. The preventing apparatus may have a plastic lens coated with a transparent conductive coating; a first electric circuit electrically connected to the coating of the plastic lens through a first conductive member; a conductive pressure plate for pressing a film toward an aperture; a second electric circuit electrically connected to the pressure plate through a second conductive member; a third electric circuit electrically connected through a third conductive member to a magazine attached to a camera; and a device for making the potentials of the magazine, the pressure plate and the plastic lens equal to each other. The preventing apparatus may have another structure for preventing the static electricity of a plastic lens.

Apparatus for preventing static electricity of plastic lens

A device for driving a varifocal lens, includes a first group frame supporting the first group of lenses therein in a movable manner for focussing and supported with the lens barrel inside said fixed frame movably in parallel with said optical axis, a second group frame supporting the second group of lenses therein in a fixed manner and supported with the first group frame inside the first group frame movably in parallel with said optical axis, at least three driver screw members disposed within the fixed frame in parallel with optical axis, at least three driver gear members held in mesh with the driver screw members respectively, and a drive unit for driving the driver gear members to thereby move the lens barrel frame and the first group frame by a predetermined amount respectively.

Drive device for a varifocal lens system

A varifocal camera, comprising a photographic lens barrel having a photographic lens able to change the focal distance and adapted to move rearwardly when the photographic lens is transferred to the first focal distance side and move forwardly when the lens is transferred to the second focal distance side, a photographic lens barrier movable between the opening position at which the photographic lens is exposed and the closing position at which photographic lens is screened, and a finder barrier movable between the opening position at which the finder lens is exposed and the closing position at which the finder lens is screened.

Varifocal camera

A finder switching apparatus in a two-focus camera in which a finder is switched in conjunction with switching of a lens of the camera between shorter and longer focuses. The finder switching apparatus has a spring mechanism which can amplify a displacement of a parallax correcting lens which is adapted to move in interlocking engagement with the lens barrel so that the mechanism for moving the parallax correcting lens can be small. Accordingly, the two-focus camera having the finder switching apparatus according to the present invention can be made compact, since the space required for storing the finder switching apparatus in the camera is small.

Growing community of inventors

Yokohama, Japan

Ikuya Tsurukawa