Abstract: A sheet conveying path switching device for use in an image forming apparatus includes a supporting member. The supporting member includes two fulcrums for supporting a separation pick and for rotatively moving the supporting member itself. An engagement portion is formed in a sheet guide plate fixed to a cover opening a space around the separation pick for removing a jammed sheet. An elastic member of the supporting member engages in the engagement portion. When the cover is opened, the separation pick and the supporting member open together with the cover by rotatively moving about the second fulcrum. When a jammed sheet is jammed between the separation pick and the cover, the cover opens without moving the separation pick and the supporting member while the elastic member is disengaged from the engagement portion.

Abstract: An electrophotographic apparatus employing a self-heat-emitting heating roller capable of causing current to flow through a heat emitting resistor at a time of turning on a power supply until a maximum electric power to be consumed in the electrophotographic apparatus, to thereby shorten a rising-up time of the heating-roller fixing apparatus. The drive starting temperature is previously set and the heat emitting resistor is selected so as to satisfy the following inequalities:V.sup.2 /R.sub.3 .ltoreq./V.sup.2 /R.sub.2 <W.sub.max -W.sub.m .ltoreq.W.sub.1 <V.sup.2 /R.sub.0 .ltoreq.W.sub.max -W.sub.s.An image forming apparatus included in the above-mentioned electrophotographic apparatus prevents an excessive current flowing through the fixing apparatus in a case of turning on the power supply on a condition that the temperature in the apparatus does not rise up sufficiently, and thereby the apparatus is not damaged. Such an apparatus can be provided at a low cost.

Abstract: An image forming apparatus includes an image forming device that forms a required image on a paper. A paper-feeding tray is capable of advancing and retreating, and is contained in a main body of the image forming apparatus, wherein a plurality of papers can be stacked thereon. A conveying path conveys the paper in the paper-feeding tray to the image forming device. A setting device sets a sort-of-paper when a special paper other than a plain paper is stacked in the paper-feeding tray. A setting device is provided in an operation panel. A setting device can set the sort-of-paper with a single key operation provided in the operation panel, when only one paper-feeding tray is provided with a separation paper-feeding mechanism which can feed paper, including special paper, regardless of the sort-of-paper, and when the special paper is stacked in the paper-feeding tray.

Abstract: In an image forming apparatus, a device for removing an image forming substance from a paper or similar image holding medium senses the orientation of fibers constituting the paper. While a light beam is emitted obliquely toward the paper, the diffused distribution distribution of the resulting reflection is measured in order to determine the orientation of the fibers. A preselected relation is set up between the fibers and the direction of paper transport on the basis of the determined orientation. Further, a condition for applying an unstabilizing liquid to the paper and a condition for drying the paper are varied on the basis of the determined orientation.

Abstract: A control operation for a fixing device which may find application in an image forming apparatus such as a printer, facsimile, or copier machine, etc. The fixing device controls a temperature of a fixing element therein, for example a fixing roller, based on a calculated compensated temperature T' of the fixing roller, which is calculated based on detected temperature of the fixing element T0 and a reference environmental temperature T1 within the image forming apparatus according to the following equations: ##EQU1## in which each of A1-A4, a1-a4, b1-b4 and c1-c4 are constants. Experimental results have indicated that such a compensation temperature value T' closely approximates an actual temperature of the fixing element. Thus, with such an operation, a temperature of a fixing element can be controlled to an appropriate value.

Abstract: In an image forming apparatus, a device for removing an image forming substance from a paper or similar image holding medium senses the orientation of fibers constituting the paper. While a light beam is emitted obliquely toward the paper, the diffused distribution distribution of the resulting reflection is measured in order to determine the orientation of the fibers. A preselected relation is set up between the fibers and the direction of paper transport on the basis of the determined orientation. Further, a condition for applying an unstabilizing liquid to the paper and a condition for drying the paper are varied on the basis of the determined orientation.

Abstract: In a digital copier of a type having plural paper trays for storing recording paper of different sizes and orientations, an automatic paper selection mechanism selects paper from a tray that produces the shortest time required to make a prescribed number of copies. Paper tray selection is based on the size of the original, magnification, paper tray position and time required to electronically rotate original image data for recording on a transversely oriented sheet of paper. These factors are used to compute a reference value that is compared to the number of copies of the original image to be made. In response, the selection mechanism will determine whether to copy the image to a longitudinal or transverse sheet on one of the trays, and rotate the image by 90.degree. if the tranverse sheet is selected.

Abstract: An image forming apparatus capable of identifying a color or colors which may be entered on a document. The apparatus automatically manipulates an image representative of a document only if the document is marked in any desired color. With the apparatus of the invention, the image forming time is reduced, and the image forming procedure is simplified.

Abstract: An image data processing apparatus includes: a printing part responsive to image signals for printing an image in a plain sheet in one of black and a different color based on a selection signal; a facsimile part for transmitting facsimile data via a communication line and for receiving facsimile data via the communication line; an image signal part for converting the received facsimile data into image data and for processing the image data to produce image signals indicating a facsimile reception image; a reading part for reading a copy image from a sheet by optically scanning the sheet and for producing image signals indicating the copy image; and a color setting part for setting a selection signal relating to each of image signals of a given pattern to a first value indicating the color if the image signals are received and for supplying the image signals and the respective selection signals to the printing part, and for setting a selection signal relating to each of the image signals of the reading part to

Abstract: An image forming apparatus having deflection scanning type and line type exposing devices and first and second developing devices arranged around a photoconductive element, so that parts around the photoconductive element are arranged with ease to promote the miniaturization of the apparatus. The exposing devices are selected based on the principle that the image quality is enhanced for an image of particular color and is lowered for an image of another color expected to be printed less frequently. Specifically, the deflection scanning type exposing device forms the image of the particular color, and the line type exposing device which has an inherently long optical path and simple structure forms the image of another color. Fans are provided to produce cooling air flow to the line type exposing device and to draw out toner dirt and ozone produced by the charger associated therewith.

Abstract: A graphics processing apparatus includes a first detection part for detecting, with respect to each pixel of an image, whether or not an edge of the image starts on a scanline, and for setting a control data depending on whether or not the edge starts on the scanline, a second detection part for detecting a duration of beam power modulation corresponding to one or plural edge pixels being intersected by a line defined in the image, and for setting a duration data, a third detection part for detecting an outermost edge pixel in the edge pixels, a part for generating a beam power data indicating an intensity level of light beam power corresponding to the outermost edge pixel, an output part for outputting the image by means of a printer having a light source for emitting a light beam, and a control means for continuously modulating light beam power of the light source from the intensity level to a predetermined level with respect to the edge pixels, so that an image with smooth edges is generated by modulating

Abstract: An optical scanner includes a varifocal semiconductor laser light source for emitting a laser beam and displacing a substantial divergent start point from a direction corresponding to a minimum divergent angle of the laser beam to an optical axis direction and arranged such that the direction corresponding to the minimum divergent angle corresponds to a cross-scanning direction; a collimator lens for changing the divergent light beam from the light source to an approximately parallel light beam in a direction corresponding to a maximum divergent angle of the divergent light beam; a deflector for reflecting the light beam from the collimator lens on a deflection-reflecting face and deflecting the reflected light beam in a main scan-corresponding direction; a first image forming optical system arranged between the collimator lens and the deflection-reflecting face and forming the light beam from the collimator lens as a linear image in a cross scan-corresponding direction; a second image forming optical system

Abstract: A graphic output device for removing the aliases of the edges of a vector image by an antialiasing procedure and effectively outputting image data undergone such processing. Whether or not the inclination of an input vector is greater than 45 degrees is determined. In the event of outputting the result of antialiasing processing, a pulse width modulation system (vertically long dot diameter) is selected if the inclination of the vector is greater than 45 degrees, or a power modulation system (horizontally long dot diameter) is selected if it is smaller than 45 degrees.

Abstract: A bicolor image forming apparatus having first and second exposing means and first and second developing means arranged around a photoconductive element. The first and second developing means are implemented as a deflection scanning type and a line type, respectively. Parts around a photoconductive element are arranged with ease to promote the miniaturization of the apparatus. This stems from the principle that the image quality may be enhanced for an image of particular color and lowered for an image of another color expected to be printed less frequently. Specifically, the apparatus has deflection scanning type exposing means for forming the image of particular color, and line type exposing means which has an inherently long optical path and simple structure for forming the image of another color.

Abstract: In an optical scanner, an image-forming optical system approximately sets the position of a deflecting/reflecting face of a rotary polygon mirror and the position of a scanned face in a conjugate relation in geometrical optics in a cross scan-corresponding direction. This optical system has a function for converging a deflected light beam onto the scanned face in a main scan-corresponding direction. The optical system is set such that the following condition, W.sub.0 /k.sub.2 <R/D<W.sub.0 /k.sub.1 is satisfied, where R designates a distance between the position of a real image and the position of an image of a light emitting section formed by an image-forming element between a laser diode light source and the scanned face; D designates a diameter of an opening image in the cross scan-corresponding direction with respect to the real image; W.sub.0 designates a waist diameter of the deflected light beam to be obtained between the real image position and the image position of the light emitting section; .

Abstract: A method for optically scanning a scanned face includes the steps of emitting a laser beam from a laser source, converging the emitted laser beam with respect to a cross scan-corresponding direction, deflecting the converged laser beam at an equi-angular velocity forward the second face, image-forming the deflected laser beam as a light spot on the scanned face by means of an f-.theta. lens system, and scanning the scanned face with the light spot, the step of emitting the laser beam including the step of modulating the laser source such that one picture element can be recorded within a period of time defined by a predetermined formula.

Abstract: An optical scanner having a deflecting device for reflecting and deflecting a laser beam issued from a light source device with a reflective surface thereof, and image forming optics for focusing the deflected laser beam onto a target surface to form a beam spot. A first aperture is interposed between the light source device and the deflecting device for correcting the diameter of the beam spot to be formed on the target surface. A second aperture is located on an optical axis between the first aperture and the target surface for intercepting, at least in a direction corresponding to subscanning, part of the light diffracted by the first aperture which lies outwardly of the first minimums.

Abstract: A scanning optical apparatus comprises a first imaging optical system for imaging a light beam collimated by a collimating optical system so as to form a linear image. The first imaging optical system includes a vari-focal lens using liquid crystal. A scanning deflector is provided for deflecting a light beam which has emerged from the first imaging optical system and for scanning a target with the light beam in a first direction. Electric circuit is provided for varying focal length of the vari-focal lens by generating changes in orientation properties of crystal liquid of the vari-focal lens in synchronization with the timing of scanning of the deflector. A second imaging optical system is provided for imaging a light beam deflected by the scanning deflector on the target. The second imaging optical system is adapted to maintain a geometrically conjugate relationship between the scanning deflector and the target in a second direction perpendicular to the first direction.

Abstract: An optical scanning device comprising a light source which emits a luminous flux for irradiating a scanning surface and comprises a semiconductor laser element and an anamorphic ellipsoidal Fresnel lens. The device further comprises a rotary polygon mirror having reflection surfaces for deflecting the luminous flux emitted from the light source. The device further comprises an image forming optical system disposed between the polygon mirror and the scanning surface for forming an optical spot image from the luminous flux on the scanning surface. The optical spot is arranged to scan the scanning surface in a horizontal scanning direction and a vertical scanning direction. The optical system is so arranged that the reflection surface and the scanning surface are positioned at conjugate points with respect to each other for the luminous flux with regard to the vertical scanning direction.

Abstract: An optical element that has a heat control unit comprising an electro-optic material member through which a linearly polarized optical beam penetrates. At least one pair of electrodes is disposed on the electro-optic material member. The electrodes sandwich the optical path of the beam. A voltage is applied to the electrodes to generate an electric field in the electro-optic material member which acts on the beam as a lens when the electric field is generated. The optical element further comprises a unit for controlling a temperature distribution in the electro-optic material member. The temperature controlling unit is disposed on the electro-optic material member.