Abstract: A dc motor wherein a driving force thereof can be used effectively with a simple and compact mechanical construction and a motor controlling system which can control such a dc motor to be driven efficiently. The motor comprises at least two coils, and change-over means for changing electric connection of the coils to change over the motor, when power is selectively supplied to the coils, between a first mode in which the torque produced is relatively high and the rotational frequency is relatively low and a second mode in which the torque is relatively low and the rotational frequency is relatively high. The motor controlling system includes selecting means for automatically selecting one of the first and second modes to control the change-over means in response to a given condition of the motor.

Abstract: A zoom lens system of the invention is double telephoto type zoom lens system having a positive/negative/positive/negative refractive power arrangement. During zooming from the wide angle side toward the telephoto side, the first through fourth lens units move such that the distance between the first and second lens units increases and the distance between the third and fourth lens units decreases. The refractive power of the first lens unit and the refractive power of the fourth lens unit are appropriately prescribed so that an adequate back focal lens distance is preserved.

Abstract: A laser beam scanning apparatus provided with a first photosensor for detecting a laser beam which has passed through an optical member and a second photosensor for detecting the laser beam without passing through the optical member to prevent the breakage of the laser beam emitting source. The intensity of the laser beam is controlled on the basis of the output signal from the first photosensor and moreover, the supply of power to a laser beam emitting source is stopped when a difference between the intensities of the laser beam detected by the first and second photosensors exceeds a predetermined value due to any contamination of the optical member.

Abstract: A wide-angle zoom lens system comprises, from the object side to the image side, a first positive lens unit being stationary on an optical axis during a zooming operation, a second negative lens unit shifting along the optical axis during the zooming operation, a third positive lens unit being stationary on the optical axis during the zooming operation, and a fourth positive lens unit shifting along the optical axis during the zooming operation, wherein the refractive power of the first and second lens units fulfills the predetermined conditions.

Abstract: A light emitter for giving plasma light emission upon application of an electric field. The light emitter comprises a resin including fine bubbles in which a gas is trapped. The gas is selected from rare gases, hydrocarbon gas and nitrogen gas. This light emitter is applicable to a light emitting device such as a plasma display.

Abstract: An image forming apparatus provided with a plurality of paper transport devices and a control device for outputting driving signals to the plurality of paper transport devices at different timings and outputting stop signals to the plurality of paper transport devices at different timings.In addition, the control device is capable of changing time difference between the timings for outputting the driving signals and between the timings for outputting the stop signals in accordance with the state of the image forming apparatus such as paper feeding conditions.

Abstract: An image forming apparatus capable of indicating document orientation for a reference to set an original document on a document platen, the image forming apparatus including a document orientation display member for displaying the document orientation at a normal copy mode in a normal display form in which the document orientation coincides with an orientation of a fed copy sheet, and at a specific copy mode which differs from the normal copy mode in a specific display form which differs from the normal display form at the normal copy mode.

Abstract: A document reading apparatus comprising a document table, a reading section disposed above the document table for reading a document placed on the document table. The reading section includes a sensor for detecting variations of brightness within a selected reading area of the document which is designated by light beams prior to a reading operation. This apparatus further comprises a display device for displaying the image of the selected reading area.

Abstract: A raster scanning apparatus for scanning a photosensitive material by modulated laser beam, the raster scanning apparatus capable of changing the picture element density of images to be formed on the photosensitive material via raster scanning in accordance with the degree of photosensitivity of designated photosensitive material.

Abstract: A finder optical system provided separately from a photo-taking lens comprises, from the object side: an object lens from forming a primary image which is an inverted image of an object and for erecting the primary image to form an erecting image; and an eyepiece for enlarging said erecting image. The object lens comprises a gradient index lens.

Abstract: A multi-color image forming apparatus forming an image of a plurality of colors in one processing by using a plurality of laser beams and a plurality of developing devices, in the case where any of the laser beams becomes unusable during forming a mono-color image, makes the image data to have been outputted from the laser beam to be replaced by that of another laser beam which can be usable, then to output it. The apparatus, in the case where any of the laser beams and developing devices become unusable because of trouble caused therein during forming an image of a plurality of colors, forms an image as an emergency measure by using the remaining usable laser beams or developing devices. Moreover, in the case where any of the laser beams and developing devices for any color become unusable because of trouble caused therein during forming an image of a plurality of colors, express the color by changing the density of another color.

Abstract: A laser beam composite apparatus which combines more than three beams including a first beam having a first wavelength, a second beam having a second wavelength and polarized in a predetermined direction and a third beam having a second wavelength and polarized in a direction perpendicular to said polarized direction of said second beam. The laser beam composite apparatus combines the first beam and the second beam based on difference of wavelengths thereof and further combines the third beam based on difference of polarized directions thereof.

Abstract: A facsimile apparatus comprises a paper discharge tray for storing original documents having been read and image-carrying recording paper. The tray is shiftable by a switching mechanism between a plurality of position for selectively receiving the documents and recording paper. The switching mechanism is operable in response to each operation for reading a series of original documents or recording a series of images on the recording paper, so that the documents and recording paper are sorted according to respective sets on the discharge tray.

Abstract: A zoom lens system comprises from the object side, a front lens group having a refractive power of a predetermined sign and a rear lens group having a refractive power of different sign from that of the front lens group. The front lens group is shiftable along the optical axis of the lens system in a zooming operation, and movable perpendicularly to the optical axis for decreasing a blur caused by a hand shake. The rear lens group is shiftable along the optical axis in the zooming operation.

Abstract: A measuring apparatus includes a flash tube for emitting flash light to a target in a first short period and a second short period, a detector for detecting amounts of light from the target in the flash light of the first short period and the flash light of the second short period, a receiver for receiving the flash light irrespective of the target to detect each reference light amount, an evaluator for evaluating the flash light according to the reference light amounts to generate a compensation signal for a characteristic of the flash light with respect to a characteristic of an ideal light source, and a calculator for calculating a characteristic value of the target under ideal light source according to the target light amount and the compensation signal.

Abstract: A camera with a multi-zone focus detecting device has an objective lens mounted on a camera. An image formed by the objective lens is divided into a plurality of zones. In each zone, a focusing condition is detected based on the image formed by the objective lens so as to produce a plurality of focusing condition data. Based on the result of the focusing conditions, one zone is selected. Furthermore, a light which has passed through the objective lens is measured separately in each zone so as to produce a plurality of measured light data. Based on a focusing condition data obtained from the selected zone, the objective lens is driven to an infocus condition. When the objective lens is driven to the infocus condition, a measured light data obtained from the selected zone is used for calculating exposure data with which the exposure is controlled.

Abstract: A light printer with a light shutter having an array of electro-optical elements is disclosed. The light printer provides with a detection circuit for monitoring temperature and/or time dependent variations regarding the electro-optical elements of the light shutter and a driving voltage control circuit for controlling an optimum driving voltage of the light shutter according to results detected by the detection circuit.

Abstract: A camera exposure data setting device for setting exposure data in digital form in response to on or off of switches. A first switch actuating member is manually operable for changing mainly an exposure time value and is located at or about the position where a shutter speed setting dial is located conventional cameras, and a second switch actuating member is manually operable for changing mainly a diaphragm aperture value and is located at a position of the camera opposite from the position of the first switch member with respect to the vertical plane passing the optical axis of an objective lens.

Abstract: An image projection apparatus including a projection lens system projecting an image of a transparent original onto an image receiving surface with a variable magnification and an illumination system illuminating the original. The projection lens system includes a plurality of projection lenses of different magnifications in an interchangeable manner or a zoom lens. The illumination system including a light source unit, a divergent lens unit and a convergent aspherical lens unit so that Kohler illumination can be realized in any magnification. A refracting power of the convergent aspherical lens unit becomes smaller than a spherical lens unit with an increase in a distance from an optical axis. The convergent aspherical lens unit may be includes a Fresnel lens.

Abstract: A reader-printer selectively switchable to a reader mode allowing an image recorded in a microfilm to be projected on a screen and a print mode allowing the image light to be projected on an image-carrying member. This reader-printer is provided with a scanning unit which is selectively movable to a position for projecting the image on the screen and a position for projecting the image on the image-carrying member. This scanning unit in the printer mode causes the image to be projected as rotated 90 degrees on the image-carrying member and allows the image to impinge as though a scanning light on the image-carrying member. As a result, when the image laid widthwise on the screen is printed on the copying paper, this image is projected in a turned posture on the image-carrying member and the copying paper on which the image has been printed is discharged through the front face of the reader-printer.