Abstract: An image forming apparatus includes an original detector for reading the size of an original, an upper sheet cassette, a lower sheet cassette, and a third sheet cassette for holding sheets of a plurality of types with different sizes, a display unit for indicating the sizes of the sheets contained in these cassettes, and a control circuit for automatically selecting the sheets corresponding to the original size, among other sheets contained in the cassettes, on the basis of the result of detection by the original detector. The control circuit controls the display unit so that the display unit indicates the sizes of all the sheets contained in the cassettes before the start of an image forming operation, and indicates only the size of the selected sheets after start of the image forming operation.

Abstract: An exposure amount for a document is adjusted by using three modes, i.e., a one-to-one magnification adjustment mode for adjusting an exposure amount for a document at a one-to-one magnification, an enlargement adjustment mode for adjusting an exposure amount for a document at a maximum magnification, and a reduction adjustment mode for adjusting an exposure amount for a document at a minimum magnification, and to control an exposure amount corresponding to a desired copy magnhification in accordance with the adjusted exposure amount. A fine adjustment mode is set through a ten-key pad of an operation panel. In this fine adjustment mode, a desired copy magnification is set between the one-to-one magnification and the maximum magnification by a magnification setting key. When an exposure amount at the set copy magnification is input through the ten-key pad, the input exposure amount is stored in a nonvolatile memory in accordance with the set copy magnification.

Abstract: This invention provides a microfilm reader/printer which in the power saving mode, namely, in the case when the machine is not in use, though the power is turned on, interrupts the supply of power to the unnecessary circuits, in particular, power to the light source drive for projecting microfilms is interrupted. Therefore, power consumption can be reduced as well as a prolongation of the life of the light source device can be realized. In addition, this microfilm reader/printer is designed so that the printing operation will not return to a prescribed printing mode even when the printing is interrupted for a fixed length of time, so that no misprints will occur even when a printing operation is resumed after a fixed length of time.

Abstract: A microfilm reader-printer which permits the setting of the number of pages of printing which exceeds a maximum number of pages of continuous printings of the printer body. The printer body outputs a completion signal to a device which sets the number of pages of printing when printing is completed. The device sends a print request signal to the printer body every time it receives a complete signal until completion of printing for the set number of pages. The printer body completes the printing operation once for each maximum continuous number of pages of printing, but resumes printing if a print request signal is outputted successively. In addition, positive and negative developers are both attached to the image forming apparatus prior to reception of a developer selecting signal.

Abstract: An erasure portion designation section designates position data corresponding to an arbitrary portion to be erased, which is not required to be copied, of the original placed on the original table. A memory stores the position data of the portion to be erased designated by the erasure portion designation section. The position data is stored in units of originals for a plurality of originals. A readout designation section designates the position data, corresponding to the portion to be copied of a plurality of originals stored in the memory, to be read out in correspondence with the original to be copied. An original scanning section optically scans the original to be copied placed on the original table to obtain an optical image. An image forming section receives the optical image obtained by the original scanning section and transfers an image corresponding to the optical image onto an image recording medium.

Abstract: A microfilm reader-printer including an image formation device having an image baring roll, a charger, an exposure apparatus, an apparatus which carries out the normal development of the image bearing roll, an apparatus which carries out the inverted development of the image bearing roll, and an apparatus which transfers the toner image which is formed on the image bearer. The reader-printer further includes a switch which specifies the size of the recording paper, an exposure shutter device, and a microcomputer. The microcomputer directs forming a toner image only in a region on the image bearer that can be transferred to the recording paper, in accordance with the size of the recording paper that is detected by a detector, in such a way as to control, in the case of the inverted development, the opening and closing of the exposure shutter device, and to control, in the case of the normal development, the charger.

Abstract: An image carrier carries an electrostatic latent image. A charger charges the image carrier to carry the electrostatic latent image. A high-voltage source supplies a high-voltage output to the charger for charging. A temperature detector detects the temperature of the image carrier. A charging controller outputs a control signal for regulating the high-voltage output of the high-voltage source in response to the temperature detection signal from the temperature detector. The control signal has the ability to compensate for changes in the charging of the image carrier by controlling the high-voltage output of the high-voltage source, in accordance with changes in temperature of the image carrier.

Abstract: There is disclosed a microfilm reader-printer which permits to be set a number of pages of printing which exceeds a maximum number of pages of continuous printings of the printer body. The printer body outputs a completion signal to a device which set the number of pages of printing when printing is completed. The device sends a print request signal to the printer body every time when it receives a complete signal, until completion of printing for the set number of pages. The printer body completes the printing operation once for each maximum continuous number of pages of printing, but resumes printing if a print request signal is outputted successively.

Abstract: An image forming apparatus with image forming area selection. An original table receives a light-transparent original document such that an original image surface selectively faces upward or downward. A light source transmits light through the original while the light source is moved with respect to the original. An erasure area specifying means specifies an erasure area portion of the original document image surface while the light source is moving. An erasure area storage means stores position data of the erasure area specified by the erasure area specifying means. An original scanning means, having an optical system moved along the original table, scans the original while the original faces downward. An image forming means focuses light emitted from the original scanning means and reflected by the original and develops an image on an image forming medium to form an image. An image erasing means selectively erases an image formed by the image forming means.

Abstract: An image forming apparatus with an image forming area selection function has an original table on which a light-transmitting original is set such that an original image surface selectively faces upward or downward, a light-transparent section for emitting light transmitting through the original set such that the original image surface faces upward on the original table while the light is shifted with respect to the original, an erasure area specifying section for specifying an unnecessary portion of the original image surface to specify an erasure area while the light from the light-transmitting section is being shifted, an erasure area storage section for storing position data of the erasure area specified by the erasure area specifying section, an original scanning section, having an optical system moved along the original table, for scanning the original placed such that the original image surface faces downward, an image forming section for focusing light emitted from the original scanning section and ref

Abstract: An image forming apparatus with a unidirectional magnification function, the apparatus comprising an original scanning unit for optically scanning an original in a predetermined direction so as to obtain an optical image, a variable magnification unit having first and second variable magnification mechanisms which vary magnifications of the optical image obtained by the original scanning unit in the original scanning direction, and in a direction perpendicular thereto, a photosensitive body which is movable in synchronism with the original scanning unit, an image forming unit for exposing the optical image onto the photosensitive body through the first or second variable magnification mechanisms of the variable magnification unit, so as to form an image which has the predetermined magnifications with respect to the original, and a unidirectional magnification unit for independently driving one of the first and second variable magnification mechanisms of the variable magnification unit.

Abstract: A copying apparatus comprises specified magnification ratio setting keys for setting specified magnification ratios and magnification ratio increasing and decreasing keys for setting a desired magnification ratio. The magnification ratio is defined as the ratio in size of the copied image with respect to the document to be copied.

Abstract: An image forming apparatus with a function to set the magnification of an image to be formed, including an input section for inputting a magnification of an image to be formed, a drive member for setting the magnification input by the input section so as to provide an image at the magnification, and a microcomputer coupled to the input section and designed to control the drive member in such a manner that the drive member sets the magnification input by the input section when no additional magnification is input within a predetermined period after the magnification has been input, and sets the additional magnification when no further additional magnification is input within another period after the additional magnification has been input, and so forth.

Abstract: An original scanning device includes a scanner for exposing an original and guiding light reflected from the original, and control means for moving the scanning means along the original at a preselected speed. The control means stores only speed data corresponding to the maximum rate of scanning and uses the data to scan at other preselected speeds.

Abstract: In a copy machine with a variable copy magnification, light reflected from a document, which is exposed by an exposure lamp, is led to a photosensitive drum to form thereon a copy image of a predetermined size and also led to a photo detecting circuit to detect a density of the document and to control an amount of exposure. An exposure control circuit of the copy machine comprises a magnification setter for generating a magnification signal dependent on a magnification as selected, a control signal generating circuit for generating a control signal according to the magnification signal and the output signal from the photo detecting circuit and a power source circuit for applying a power voltage to the exposure lamp according to the control signal.

Abstract: An image forming apparatus providing a continuously variable copy ratio. A first drive mechanism optically scans an original by moving a lamp. A second drive mechanism varies a distance (a) from the original to a lens of an optical system and also a distance (b) from the lens to the photosensitive drum. A third drive mechanism rotates the photosensitive drum. A control unit causes the second drive mechanism to make a ratio (b/a) between the distances (a) and (b) coincident with the specified copy ratio data input from a normal key group while an equation 1/a+1/b=1/f (f: a focal length of the lens) is satisfied and also causing the first and second drive mechanism to make the ratio of the speed of optical scanning to the ratio of the speed of movement of the photosensitive drum coincident with the specified copy ratio data.

Abstract: A copying machine includes: a rotatable photoconductive drum and an optical assembly, having optical elements, for optically scanning a paper document, and forming an optical image corresponding to an optical document image on a photoconductive drum surface. The optical assembly includes: a lens; a first mirror section for introducing the image to the lens; and a second mirror section for introducing an optical image from the lens onto the drum. The position of the first mirror section relative to that of the second mirror section varies under mass production conditions although the relative positional relationship is preset in accordance with the inherent focal length of the lens.