Abstract: In a apparatus for forming a digital image with use of electrophotographic process wherein the gradation is expressed by changing the laser intensity according to image information, at least one of the surface electric potential V.sub.O of photoconductor and the development bias electric voltage V.sub.B is controlled, and the laser intensity is controlled for gradation correction to compensate a change in gradation due to the control of V.sub.O and V.sub.B. A ratio of variable differences of potential in the apparatus, (V.sub.B -V.sub.I)/(V.sub.O -V.sub.I), is kept constant to control the gamma characteristic in the apparatus.

Abstract: An electrical device for controlling heater has a power supply connected in parallel with a heater or the like. A reducer such as a resistor is provided for reducing electrical current flowing into the heater. A switch can be operated by a controller to connect the heater to the electrical power supply or to connect the heater and the reducer in series to the electrical power supply. The controller operates the switch to disconnect the heater from the electrical power supply after operating the switch to connect the heater and the reducer in series to the power supply. Thus, even at a timing when the load of the power supply is the maximum and the capacitor charging current to the power supply increases, the change in the current through the heater becomes gradual, and the harmonic components in the current do not increase by using the reducer even if the timing of the maximum load overlaps with the timing of the stop of power supply to the heater.

Abstract: An image of an original mounted on a platen is converted into image data by a CCD. An original region detection unit detects the region of the original mounted on the platen from the image data. According to this detection, the writing address of the image memory is controlled so that image data of the center of the original mounted region is written into an address matching the center of the sheet. As a result, various image editorial processes can easily be carried out in a digital copy machine.

Abstract: Camera capable of indicating set photographic field by masking an area out of the photographic field nearby an image forming plane within a visual field of a viewfinder or lowering transmittance of the area in accordance with a change of photography format such as from an ordinary shot to a panoramic shot. The camera includes light-receiving elements for photometry which output a signal in response to amount of light transmitted through the image forming plane within an optical path of the viewfinder, a correcting circuit for correcting the element output in response to the set photographic field, and a photometry circuit for calculating a photometric value.

Abstract: A projector projects an image. A scanning mirror deflects the projected image by mirror oscillation method. A reading device reads the projected image deflected by said scanning mirror and outputs an image data corresponding to the projected image. A discriminating device discriminates which projection lens is mounted on said projection lens mount among said plurality of lenses. A memory device stores respective distortion data of said plurality of projection lenses and distortion data concerned with a distortion being due to the oscillation method. A correcting device corrects distortion of the distortion data of the projection lens which is discriminated to be mounted on the projection lens mount and the distortion data concerned with a distortion being due to the oscillation method.

Abstract: An image forming device having a transfer unit that transfers the toner image formed on the image carrier onto transfer paper, such that the toner image can be transferred with good results regardless of fluctuations in the environment, by (a) returning to the feedback side of the power source, via a constant voltage element, part of the electric current that flows to (i) the transfer unit, to which a prescribed voltage is applied by the power source, and (ii) the guide member that supports the transfer paper, said electric current flowing to said guide member via said transfer paper, and by (b) controlling the voltage of the power source such that the voltage on the feedback side of the power source will be constant.

Abstract: A first light receiving portion and a second light receiving portion are provided on the upper surface of a moving body having driving wheels at an interval of a prescribed distance in a plane. The first light receiving portion and the second light receiving portion rotate around the axis in the vertical direction. On the other hand, a first light emitting portion and a second light emitting portion are provided on the side face of a station serving as a reference station at an interval of a prescribed distance in a plane. The first and second light receiving portions carry out sampling while rotating, so that the quantity of light reception is changed according to the directivities of the first and second light receiving portions. When the peaks of the directivities of the first and second light receiving portions match the direction of the first light emitting portion or the second light emitting portion, the quantity of light reception is maximized.

Abstract: An imaging optical system transmits a primary image. The optical system does not form an intermediate image. The primary image is projected on a screen as a secondary image. The optical system has a projection optical system and a reflection optical system. An optical axis of the reflection optical system forms an angle other than 90.degree. with respect to a screen-side image surface.

Abstract: A camera is equipped with a finder having a field-of-view frame switching mechanism that is provided with, in addition to a stationary frame plate disposed in an optical path, two rotatable frame plates each of which moves in the optical pass to overlap with the stationary frame plate, to define three fields of different sizes. The stationary frame plate has a window of a standard size, one of the rotatable frame plates has a window of a classic size and the other has a window of panoramic size. Each of the fields of view is defined by a single frame plate. When the rotatable frame members are at their retracted positions, they substantially overlap with each other and are pushed by a spring in a direction to move in the optical path. Their movement is controlled by a cam member, which is moved in accordance with a user's operation to switch the size of a picture taken by the camera.

Abstract: A sterilizer supplies liquid over an object and then irradiates far-infrared radiation to the object. The object is fully sterilized since the supplied liquid well absorb far-infrared radiation with sterilizing effect.

Abstract: An image forming apparatus records an image on a recording medium after correcting a slant of the image according to a type of document sheet or an operating history of the image forming apparatus. Normally, a slant of the document sheet is corrected by bringing one edge of the sheet in contact with a document scale provided on a document platform. When the sheet is of thin paper or sheets of different sizes are mixed, an image signal obtained by scanning a document image is electrically processed so as to correct a slant of an image to be recorded. When the image signal is electrically processed so as to correct the slant of the image to be recorded, the correction of image slant may be based also on the operating history of the image forming apparatus, for example, the total number of sheets transported, the number of times a paper jam has occurred or the cumulative value of the slant angle of the image.

Abstract: In a digital image forming apparatus, when a latent image is formed on a photoconductor, a light from a light source is emitted in a period of a duty ratio while modulated according to image data, and the latent image is developed and transferred onto a sheet of paper. The duty ratio, defined as a ratio of a light-emitting time of a light exposing the photoconductor to a period for exposing a dot, is changed in the same document according to dot information on the document such as an edge signal. In the modulation of the optical intensity, the light emission onto the photoconductor is performed with a duty ratio which may be set for each dot. Image portions formed with different duty ratios may exist at the same time in a reproduced image. For example, an edge portion in a document is reproduced at the duty ratio of 100% while a non-edge portion is reproduced at the duty ratio less than 100%.

Abstract: A scanning optical system has a deflector and a scanning lens. A convergent beam is deflected at a uniform angular velocity by the deflector. The scanning lens forms the scanned beam into an image on a scanned surface to scan the surface substantially at a uniform velocity. The scanning lens includes from the side of the deflector a negative lens element and at least one more lens element. The convergent beam is incident on a surface of the deflector which faces the deflector. The scanning lens fulfills predetermined conditions.

Abstract: A belt fixing system for fixing a toner image to a sheet includes an endless belt. This belt is rotatably supported by a plurality of supporting members, or rollers. Also, the belt is heated by a heater such as lamp and rotated around the supporting members by a drive member such as motor. When a toner fixing has finished, the heater is switched off and then after a predetermined time period the drive member is halted. Preferably, the time period is a time required for the belt to make two revolutions. This approach prevents the belt from being heated too much, which extends the durability of the belt.

Abstract: The present invention relates to a toner for developing an electrostatic latent image, comprising a calix arene compound expressed by the following general formula ?I!: ##STR1## wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, an alkyl group having a carbon number of 1 to 5, or --(CH.sub.2)mCOOR.sub.3 (in which R.sub.3 represents a hydrogen atom or a lower alkyl group; and m represents an integer of 1 to 3); n represents an integer of 0 to 7.The present invention further relates to a charge-giving member comprising a calix arene compound expressed by the foregoing general formula ?I!.

Abstract: The present invention relates to an induction heat fixing apparatus for heating a transporting medium containing: a system for generating an induction heat by using an induction current; a pressure member disposed in pressing contact with the induction heat generating system at a contact portion; and a preheating member positioned at upstream side of the contact portion with respect to the transporting direction of the medium, whereby the preheating member is heated by the induction current generated by the induction heat generating system. One object of present invention is to prepare an induction heat fixing apparatus which is compact and has high efficient heating.

Abstract: A contact type sensor for sensing an object includes a body; and a contacting member which contacts the body and a shaft. One end of the shaft is connected to the body of the sensor and another end of the shaft supports the contacting member. The shaft is rotatable within a predetermined plane, and the shaft is more flexible in a direction perpendicular to the predetermined plane than in a direction parallel to the predetermined plane.

Abstract: A toner produced by pulverizing and classifying a melt and kneaded mixture comprising a binder resin, a colorant and an offset preventing agent, said binder resin comprising a styrene-type copolymer and said offset preventing agent comprising a polypropylene having a softening point of 135.degree. to 155.degree. C. and a polyethylene having a softening point of 100.degree. to 150.degree. C., wherein a total amount of said polypropylene and said polyethylene is 2 to 10 parts by weight per 100 parts by weight of the binder resin and a weight ratio of said polypropylene to said polyethylene is 1:3 to 1:1, and said pulverizing and classifying carried out by a pulverizer and classifier which impart mechanical impact on a particle to be treated.

Abstract: An optical system projects an enlargement of an image of an object surface on a screen inclined relative to the object surface. The optical system includes an afocal first lens unit including a diaphragm and at least a second lens unit. The optical axis of the afocal system is not collinear with a normal line from the object surface, i.e., the afocal system is eccentric to the object surface. The second lens unit is eccentric relative to the afocal lens unit.

Abstract: The image forming apparatus is provided with a detecting means for detecting transfer efficiency when transferring a toner image from a photosensitive member to a transfer sheet, and a developing efficiency changing means for changing developing efficiency based on the transfer efficiency detected by the detecting means, and corrects the toner consumption predicted by the predicting means based on the transfer efficiency as detected by the detecting means, so as to determine the amount of toner to be replenished. When the developing efficiency is changed based on the transfer efficiency, toner consumption also changes, and does not match the predicted toner consumption. According to the present invention, toner concentration in a developer can be even more accurately controlled by correcting the predicted toner consumption by the change in transfer efficiency.