Abstract: A halftoning method utilizes staged, overlapping pixel intensity growth in a halftone cell in rendering a halftone image with multi-level pixels.

Abstract: An image processing apparatus includes an edge detecting unit which identifies an area of given image data as a gradation sequence area and a character/line art area and which outputs edge information of the character/line art, a level converting unit which generates a strength modulation signal so as to emphasize an edge of the character/line art area, a laser driver which outputs a laser drive signal in order to form a picture dot larger than a standard size in response to the strength modulation signal. Further, according to the present invention, it is possible to print an image with emphasizing an edge portion of a character/line art by a laser printer.

Abstract: Full-format screened data is processed in a computer-implemented method to identify zones that contain printable information. The zones are packed, imaged and made into flexo plates, and elements cut out from the plates for each zone of printable information. The plates use less flexo material than the full-format screened data. The cut elements are accurately placed on a flexo plate carrier to form a set of plates on a carrier for printing the full format screened data.

Abstract: The present invention is an automated arrangement for applying strip material to a web belt. One purpose of the present invention is to provide a solution to the known problem of securing material to an organic photoconductor (“OPC”) belt material in an automated manufacturing environment. Usually, material is applied to an OPC belt by hand. Hand application of strip material is time-consuming, costly, and prone to inaccurate placement on the OPC belt. The extra time taken to apply the strip material by hand increase the OPC belt's exposure to light, which can damage the OPC material. Furthermore, pulling the strip by hand can deform the strip because of excessive force used to pull the strip before application. Thus using an automated, controlled process to apply material minimizes damage to the belt and strip, resulting in higher yield of belts and strips per spool.

Abstract: An image reading method controls an image reading system including an image reading apparatus having a mechanism for scanning photographic film and a host computer receiving image data from the image reading apparatus. The method has steps of detecting each of image component of dust resulting from dust stuck to the photographic film which is read by the image reading apparatus, and removing only the image component of the dust resulting from the read dust to correct the image data.

Abstract: A system for generating a photographic product from a digital image. A gateway server receives a request from a photographer for a list of options for photographic products. The gateway server transmits a display of a list of options to the photographer. The photographer submits an order for a photographic product to the gateway server. The gateway server then transmits the order to a fulfillment center to process the order. The gateway server then transmits routing information to the photographer for transmitting a digital image to the fulfillment center.

Abstract: A method for determining defects in an image sensor, which identifies one or more partial column defects, including capturing a digital image using the image sensor and storing such digital image in a memory; identifying at least one column in the digital image which has corrupted data caused by one or more defective pixels in the image sensor; processing the digital image data from the at least one identified column using an extended differentiation filter; and using the output of the extended differentiation filter to identify a starting position or an ending position of the partial column defect.

Abstract: Documents to be transmitted, not-yet-transmitted documents and information about addressees of not-yet-transmitted documents are stored in a storage device. When a call was received, caller information from a network is also acquired by a caller information acquiring portion. The caller information is compared with addressee information for respective not-yet-transmitted documents. If the addressee information is matched to the caller information, the not-yet-transmitted document is retransmitted automatically to the address specified by the caller information.

Abstract: A facsimile apparatus can notify a user of the fact that facsimile data being received is sent from a specific party. A communication control part receives facsimile data and party information from a remote facsimile apparatus, the party information identifying the remote facsimile apparatus. A melody output part stores and outputs a call-notification-melody so as to output the reproduced call-notification-melody through a speaker. A specific party discrimination part stores specific party information regarding a specific party for which the call-notification-melody is output. A system control part cases the melody output part to reproduce and output the call-notification-melody stored when the party information which the communication control part acquired matches the specific party information stored in the specific party discrimination part at a time of reception of a call.

Abstract: The present invention provides an image forming apparatus includes a scanner unit which scans a plurality of photographic images and which outputs image information upon receiving instruction of automatic edit processing, an extracting unit which extracts a position and a size of each of the plurality of photographic images, an image editing unit which outputs an edit image, in which the plurality of photographic images are laid out within a predetermined layout, on the basis of the position and the size of each of the plurality of photographic images, and a printer unit which prints the edit image on an image forming medium. According to the present invention, scanning a plurality of photographs at the same time allows a photograph album to be automatically printed out.

Abstract: An image transmission apparatus is provided with a FAX modem, an encoding/decoding section, a digitizer-integrated LCD, encoded image data memory, original image data memory, and additional image data memory. Original image data received by the FAX modem are temporarily stored in the encoded image data memory, and the original image data are decoded by the encoding/decoding section. The thus-decoded original image is stored in the original image data memory. An image of the thus-stored original image data is displayed on the digitizer-integrated LCD. An operator draws an additional image on the digitizer-integrated LCD. Data of the thus-drawn additional image are stored in the additional image data memory. The thus-stored additional image data are encoded by the encoding/decoding section, and the thus-encoded additional image data are temporarily stored in the encoded image data memory. Then, the encoded additional image data are sent by the FAX modem.

Abstract: In accordance with the present invention, an operating procedure of a scanning system with one-scan-and-done feature is disclosed. The operating procedure comprises steps of receiving parameters input by a user, scanning an original responsive to the parameters, displaying an image corresponding to the original, receiving a portion of the image selected by the user, and outputting the selected image. The present invention can be extended to a scanning method for using a scanning system with one-scan-and-done feature and a scanning system with one-scan-and done feature.

Abstract: There is a problem that the contact-type image sensor, for adoption in an image input/output apparatus to input/output the image of a large-sized document, such as A0 or A1 size, is weak in lengthwise rigidity and readily deflected at its lengthwise center by its own weight. Accordingly, by attaching a deformation rectifier to the image sensor in a lengthwise direction thereof, the contact type image sensor is reinforced in lengthwise rigidity. The deformation rectifier reinforces the rigidity of the contact type image sensor, thereby preventing the contact type image sensor from deflecting vertically relative to its lengthwise direction and keeping constant the focal length between the surface of the document to be read and the sensor IC.

Abstract: A scanner is provided with a small and low-priced lighting member. The scanner scans an object having undulations on a surface thereof with good quality. The object is placed on a scanning platform. A CCD line sensor incorporated in a camera is positioned facing the scanning platform and scans the object line by line, while moving along an image plane on a lens of an optical scanning system for a specified distance. The lighting member irradiates a scanned position with light from above in a slanting direction under the same condition. The lighting member is moved in synch with the scanned position shifted when the CCD line sensor scans one line, so that the irradiation angle is constant entirely on the object to be scanned. Therefore, shadows of the undulations on the surface of the object are formed under the same conditions as those observed under the natural light without loss of stereoscopic effect of the object.

Abstract: A digital copying machine comprising an image scanner part for reading an original image to reproduce image data of the original image, a laser printer part for printing an image according to given image data, a removable memory card, and a reader/writer of the memory card is provided. For offline print, the image data of a document prepared in an external computer and output control data are stored into the memory card. By installing this memory card in the digital copying machine, the digital copying machine prints the image data read out from the memory card offline in a desired output form. For offline image input, read control data obtained by using an image scanner such as a read gradation level, a read size, density, and the degree of edge enhancement is stored in the removable memory card using software executed in an external computer.

Abstract: An exposure device has a light emitting unit for emitting a laser beam based on an image signal. The laser beam emitted from the light emitting unit is incident on a polygon mirror through a cylindrical lens. The laser beam reflected on the polygon mirror is illuminated on the surface of a photo sensitive drum through two f&thgr; lenses and a mirror. By doing so, an electrostatic latent image is formed on a drum surface on the basis of an image signal. Further, the exposure device has a housing for holding the light emitting unit, cylindrical lens, polygon mirror, f&thgr; lenses and mirror in a mutually and highly accurate state. A dowel is so provided as to project from the bottom of the housing and functions as a rotation shaft for rotating the exposure device. The dowel is provided on an axis passing through an exposure light spot illuminated in the drum surface by the laser beam.

Abstract: A bracket that rotatably supports a shaft provided along the axis of a back roller for feeding and thereby transporting a document pinched between the back roller and a close-contact-type image sensor elastically supported on a cabinet and that is fitted to the cabinet so as to be rotatable about the shaft is formed integrally with a release lever for releasing the back roller and the close-contact-type image sensor from a state in which they are pressed against each other.

Abstract: An image reading device includes a main body and an openable cover. A sheet feed path is defined inside the cover. An intermediate portion of the sheet feed path is exposed to the top surface of the main body, thereby the top surface defines a part of the sheet feed path at the intermediate portion. The cover is provided with a sheet feed mechanism. Feeding of the sheet is terminated when the cover is opened. The image reading device further includes a sheet location detection system that detects a location of the sheet when the feeding of the sheet is terminated, and a controller determines whether the sheet is to be discharged from the sheet feed path, when the cover is closed, in accordance with a location of the sheet detected by the sheet location detection system.

Abstract: A reference chart including a plurality of patterns for sampling each of characteristic quantities indicating characteristics of a defective image is read by an image scanner targeted for checking, and image data is stored in a memory. An image analyzing section samples the characteristic quantity of each of the plurality of patterns expressed in the image data. Sampling of the characteristic quantities is hardly affected by a displacement between ideal image data and the above stored image data. A correlation table holding section holds a correlation table which associates each phenomenon name for classifying defective image and at lest one of the characteristics quantities corresponding to the phenomenon name. Referring to the correlation table, a phenomenon name specifying section specifies a phenomenon name of a pattern region in which the characteristic quantity is sampled by the characteristic quantity sampling section from among the plurality of patterns expressed in the image data.

Abstract: A document-backing surface for reducing show-through when a duplex-printed document is scanned but without producing undesirable artifacts. The document-backing surface has a plurality of first and second light-absorbing surfaces, and a plurality of specularly reflective surfaces partially covering each of the second light-absorbing surfaces. The first specularly reflective surfaces are oriented to reflect light from a scanner lamp to a scanner sensor. In an alternate embodiment, the document-backing surface is partially covered by a specularly reflective surface oriented to reflect light from the scanner lamp to the scanner lens. In another embodiment, the document-backing surface has a set of teeth, each of which has light-absorptive first and second tooth surfaces and a specularly reflective surface partially covering each second tooth surface. In addition, the present invention is directed to a method for using a document-backing surface.

Abstract: An optical deflector of the present invention includes a movable mirror and torsion bars supporting the mirror and formed integrally with the mirror. The mirror reciprocatingly vibrates to reflect a light beam to thereby deflect it. The mirror is curved in the form of an arch in a section including at least the torsion bars. The mirror deforms little during vibration even if it is thin. Small power can cause such a thin mirror to vibrate with a large amplitude.

Abstract: A four-line CCD sensor is structured by line sensors R, G, B in which color filters are respectively disposed on surfaces of light receiving elements, and a line sensor BK at which no color filter is disposed. Amplitudes of signals which are outputted from the line sensors R, G, B at a time of reading a color document, and an amplitude of a signal which is outputted from the line sensor BK at a time of reading a monochrome document are adjusted so as to be substantially equal to one another. In a case in which a color document is read, outputs of the line sensors R, G, B are selectively provided, and in a case in which a monochrome document is read, output of the line sensor BK is selectively provided.

Abstract: An image reading device includes a light source for illuminating an image in a developed photo film by applying illuminating light thereto. An area CCD reads the image by photoelectrically detecting the illuminating light reflected by, or transmitted through, the developed photo film, to obtain image data respectively of pixels. An input unit inputs information of a photo film type, printing size or printing magnification. A determiner determines whether the photo film type, printing size or printing magnification satisfies a predetermined data correcting condition related to image data correction. An image processor extracts a group of inappropriate pixels from the pixels by checking the image data if the photo film type, printing size or printing magnification satisfies the data correcting condition, and corrects the image data of the inappropriate pixel group.

Abstract: An image processing method for obtaining processed color image signals from image signals on a silver halide photosensitive material, having the following steps: transforming color image signals into a luminance signal and color information signals; applying a high-frequency component suppression processing to the color information signals; decomposing the luminance signal into a luminance low-frequency component signal, a luminance medium-frequency component signal, and a luminance high-frequency component signal; applying a processing, in accordance with requirement, to the luminance low-frequency component signal; applying a suppression processing to the luminance medium-frequency component signal; applying an emphasis processing to the luminance high-frequency component signal; composing a processed luminance signal through combining the processed luminance low-frequency component, the processed luminance medium-frequency component signal, and the processed luminance high-frequency component signal; and t

Abstract: In accordance with the present invention, an operating procedure of a scanning system free of identifying original's attribute comprises steps of scanning at least one original free of identifying original's attribute to generate at least one image, wherein the images present all contents of the originals, displaying the images on a preview window, receiving a portion of the preview window selected by a user, and scanning a portion of the originals corresponding to the portion of the preview window. The present invention further extends to a scanning system free of identifying original's attribute and a scanning method without identifying an original's attribute by a user.

Abstract: A method and system for enhancing images utilizes the direction of a detected edge within an image block of an input image to selectively smooth or sharpen a pixel of the input image that corresponds to that image block. The direction of a detected edge within the image block is determined by computing the horizontal gradient and the vertical gradient, and then using the ratio of the computed gradients. In an exemplary embodiment, the method and system is designed to exclusively use bit shifting to perform multiplications, rather than using digital signal processing. Consequently, the method and system is suitable for implementation in printer firmware and/or hardware.

Abstract: The present invention provides a method and apparatus for producing holographic stereograms. Holographic stereograms have made possible the creation of holograms of both real objects in natural or studio lighting and virtual objects created using three-dimensional graphics. There are several approaches for creating holograms from digital graphics. This paper discusses the application of the light valve to the process along with other related developments. Artists can now produce high quality inexpensive, medium-format holograms using this direct-link to digital media. Future developments will led to even higher resolution Digital Image-Light-Amplifier (D-ILA) systems.

Abstract: Performance monitoring and equalization of DWDM optical links equipped with optical add/drop multiplexers (OADMs) at one or more sites is effected by selecting a direction of transmission and the end sites from the point of view of equalization.

Abstract: A beacon beam is transmitted from a receiver to a transmitter. The transmitter generates and transmits a conjugate beacon beam back to the receiver, where it is interfered with a local oscillator beam to form a hologram. The hologram is used to configure a spatial light modulator as a diffraction grating. A conjugate communications laser beam containing information is subsequently transmitted to the receiver. The diffraction grating deflects the conjugate communications beam to a fixed and known direction, whereupon it is directed through a spatial filter.

Abstract: The invention provides a method for measuring transmission loss in an optical transmission line between a master station and a slave station, and also a slave station, a master station and a star network communication system using this method. Power of an optical signal is measured at a second end of an optical transmission line connected with an added slave station and at a first end other than the second end. The result at the first end is stored in a storing unit or transmitted to an incorporating unit by a transferring unit. The incorporating unit incorporates the result into a downstream optical signal, which is transmitted to the slave station. In the slave station an information extracting unit extracts the result from the downstream optical signal, and a processing unit calculates a difference between the measurement results of the first and second ends to obtain transmission loss therebetween.

Abstract: An apparatus and method for transmitting simultaneous independent data signals over an optical fiber includes converting the data signals into corresponding optical signals and introducing the optical signals into the fiber without necessarily reformatting the data signals to conform to communication standards or synchronizing them. The data signals could include digital streaming video signals, voice signals, data signals etc.

Abstract: Methods and apparatus for multiplexing and demultiplexing optical signals. An interleaver having a modified Mach-Zehnder interferometer as a first stage is used as a wavelength division multiplexer. This first stage is combined with one or more cascaded stages, each having a beam splitter and an optical delay element. A light beam including a number of signals at different wavelengths is received. The beam is split such that approximately half of each signal is contained in one of two sub-beams. One of the two sub-beams passes through a delay element, which provides a phase shift. The two sub-beams are recombined and split again. Each wavelength adds constructively or destructively in the new sub-beams such that the signals are separated—some wavelengths are in one of the new sub-beams, some are in the other. One of these sub-beams is delayed, and the two are combined and split again, improving the separation.

Abstract: A channel allocation apparatus of an OSU in a WDM system includes: an optical signal converter for performing a conversion operation between an E1 data frame and an optical signal; a channel allocating unit for performing a counting operation by a certain unit on the E1 data, detecting an channel allocated to the E1 data or allocating a channel to the E1 data; an E1 framer for reframing the E1 data frame outputted from the optical signal converter to output it to the channel allocating unit, and framing the E1 data outputted from the channel allocating unit to output it to the optical signal converter; and a microprocessor for controlling an operation of the E1 framer. After the E1 data is counted by a certain unit to sequentially identify a plurality of channels, a channel data is assigned to a corresponding channel or a channel data assigned to the channel is detected.

Abstract: The present invention provides an optical module having a light-emitting device for outputting a laser beam, a first temperature sensor disposed in proximity to the light-emitting device for sensing the temperature in the light-emitting device, a first temperature adjustment unit for adjusting the temperature in the light-emitting device, a wavelength monitor for receiving and monitoring the laser beam from the light-emitting device after passed through an optical filter, a second temperature sensor disposed in the wavelength monitor for sensing the temperature in the wavelength monitor, a second temperature adjustment unit for adjusting the temperature in the wavelength monitor, and a third temperature sensor disposed directly in or in proximity to the optical filter for sensing the temperature in the optical filter.

Abstract: An optoelectronic device that has a network address (e.g., IP address) and participates in in-band traffic for purposes of performing functions (e.g., network diagnostics, network control, network provisioning, fault isolation, etc.) that are traditionally performed by host equipment. An embodiment of the invention may have a protocol engine and a status monitoring module. The protocol engine identifies data packets that are addressed to the optoelectronic device, and allows the optoelectronic device to insert packets of information generated by the device into in-band data. Logic of the optoelectronic device may modify the operating parameters of the device according to the control information included in the data packets. The status monitoring module detects the device's physical conditions and the conditions of its links.

Abstract: An optical configuration includes a Mach-Zehnder interferometer and a directional coupler. Both the Mach-Zehnder interferometer and the directional coupler have a first arm and a second arm. The Mach-Zehnder interferometer and the directional coupler share a common arm.

Abstract: An optical communication interface module connected to connected to a direct-current (DC) power terminal, an input/output (I/O) terminal and a ground terminal, to perform optical communication. The module includes a PNP transistor for transmission, a pull-up device, a photo generator device, a photoelectric converter, and first and second NPN transistors for reception. The PNP transmission transistor has its base connected to the I/O terminal and its collector connected to the ground terminal. The first transistor for reception with its collector connected to the anode of the photo generator device and its emitter connected to the ground terminal, has its base driven by output signals of the photoelectric converter. The second transistor for reception with its collector connected to the I/O terminal and its emitter connected to the ground terminal, has its base driven by an output signal of the photoelectric converter.

Abstract: The attenuation profile of an optical system, which defines the power variation as a function of wavelength is adjusted to alter the slope of its contour. The device is useful in a wavelength division modulation system to flatten the profile of an amplifier or the like that has a non uniform power variation with wavelength. The invention adjusts the slope by first providing an input light signal that has a known polarization state, e.g., processing the input into a known phase and amplitude relation between orthogonal components, such as plane polarized at a given alignment. The signal is then passed through a series of waveplates. The waveplates have different phase retardation and orientation resulting in wavelength dependent polarization change. According to an inventive aspect, by tuning the phase retardation of multiple tunable waveplates the desired wavelength dependent polarization changes over a useful wavelength range can be produced.

Abstract: The present invention relates a method of influencing a group delay of an optical signal, comprising the steps of a: splitting a beam of the optical signal into n parts, each part traveling an optical path, n being a natural number greater zero, b: splitting all of the n parts into m subparts, each part traveling an optical path, m being a natural number greater zero, c: superimposing the kth subpart of at least two of the m subparts to a resulting kth superimposed part, k=1, d: repeating step c for k from 2 to m, e: performing steps b to d at least one time with at least two of the superimposed parts, f: using at least one of the resulting superimposed parts for influencing the group delay of the optical signal.

Abstract: A smart node is provided for use in an optical communications network wherein the smart node comprising dynamically reconfigurable optical signal manipulation devices in combination with sensing devices and processors to provide real time closed and open loop control of various channels of the network.

Abstract: The present invention provides a passive optical network system having an optical line terminal for transmitting a plurality of types of distributed data using optical signals and a plurality of optical network terminations for receiving distributed data using optical signals. Each of the plurality of optical network terminations transmits a reception request for at least one of the plurality types of distributed data to said optical line terminal while designating the type. The optical line terminal transmits distributed data of the designated type among the plurality of types of distributed data to the plurality of optical network terminations.

Abstract: A repeater apparatus (1001) is constituted from infrared transmitter sections (1s, 2s, 3s) and infrared receiver sections (1r, 2r, 3r) as well as connection control sections (1C, 2C, 3C) and further a repeater section (101), thereby attaining independent communications with the individual one of several associated equipments with respect to infrared communication apparatus of the direct emission type which supports only one-to-one (1-to-1) or one-to-several (1-to-N) communication schemes, thus enabling achievement of N-to-N communication forms by performing transfer of data information being received by each communication equipment to others.

Abstract: A frequency translating device (FTD) includes at least one light-activated resistor (LAR) connected to down-convert a radio frequency (RF) to an intermediate frequency (IF) and to up-convert an IF to an RF and a source of modulated light that is optically connected to the LAR. The source of modulated light is modulated in response to a local oscillator (LO) and the LAR is activated in response to the modulated light. Modulated light can be generated from a light source and an LO by, for example, directly modulating the light source, modulating a transmission switch that blocks the transmission of light to the LAR, or modulating a light path switch. The LAR-based FTD can be used as a reciprocal FTD to characterize another FTD in a three-pair measurement system. An FTD may include more than one LAR to form, for example, single-balanced and double-balanced LAR-based FTDs.

Abstract: A method and system for generating both return-to-zero (RZ) and carrier suppressed return-to-zero (CSRZ) shaped signals using only a single optical modulator. The system includes: a switch for receiving a data signal and a clock signal as inputs, and outputting a voltage signal; a unit for controllably adjusting the phase of said clock signal before input to the switch; an optical modulator for receiving a continuous wave light (CW) signal and the voltage signal as inputs, and outputting one of an RZ and a CSRZ signal. To generate a CSRZ signal, the optical modulator is biased at a transmission minimum level signal. To generate an RZ signal, the optical modulator is biased at a transmission maximum level and the clock signal is phase shifted. Also disclosed is an optical communication transceiver including a plurality of optical modulator circuits generating both RZ and CSRZ signals.

Abstract: Methods of optical communication and optical communication systems are described. According to a first aspect, a method of optical communication includes providing an optical signal and providing a plurality of data signals. This aspect also includes passing a plurality of desired portions of the optical signal using a plurality of respective optical modulators, the desired portions individually having at least one predefined wavelength. The method also includes optically modulating the desired portions of the optical signal using the respective optical modulators and responsive to respective ones of the data signals and outputting the desired portions of the optical signal to an optical communication medium after the modulating.

Abstract: An optical system for receiving an incoming beam of electromagnetic radiation, for dividing it into a transmitted beam, containing a part of the wavelength band of the incoming beam, and a reflected beam, containing the remainder of the wavelengths in the incoming beam, and for transferring the transmitted beam continuously to a detector. The system is capable of switching the reflected beam between any one of two or more detectors. The system comprises an objective lens, a dichroic beamsplitter cube, a first detector, capable of detecting radiation in a first wavelength band, a second group of two or more detectors, each capable of detecting radiation in a second wavelength band and means of rotating the dichroic beamsplitter cube, so as to switch between the detectors of the second group.

Abstract: A decision system for a modulated electrical signal delivered by a converter in response to a received modulated optical signal compares the amplitude of the electrical signal to a reference level, measures an average amplitude of the electrical signal, and generates the reference level as a function of the result of such measurements so that the “reference level/average amplitude” ratio can be adjusted to a predetermined constant value different from 1. Applications include receivers for optical packet transmission systems.

Abstract: A method for capturing images useful in a scanning system is provided. The present method comprises performing a preview scan of a picture and then displaying the preview image of the picture on a screen. Selecting a scanning area of the preview image and simultaneously performing a first normal scan of the picture from an initial scanning position relative to the picture. When the scanned area of the first normal scan corresponds to the selected scanning area, the scan image produced by the first normal scan is displayed. Otherwise, a second normal scan of a portion of the picture that corresponds to the selected scanning area is performed to produce a final scan image.

Abstract: A mounting mechanism is disclosed for a strap member in which the orientation of a surface of the strap member, such as a reflecting mirror, is adjustable. In particular, the strap member may be a cylindrical mirror for reflecting light beams to image carriers such as sensitized drums on which images are recorded in an optical reproductive scanning apparatus. The mounting mechanism allows the strap member to be readily fixed in position without causing positional changes of the strap member that would change the magnification and/or cause skew changes in scanning lines when the strap member is a cylindrical mirror in an optical scanning apparatus.

Abstract: It is an object of this invention to provide a light scanning device capable of suppressing scanning line bending to a low level, which is caused by the arrangement error of a single-element lens serving as an imaging optical element, and an image forming apparatus using the device. In order to achieve the object, according to this invention, an imaging optical system is formed from a single-element lens, and the sectional shapes of the incident and exit surfaces in the main scanning direction are non-arcuated, and the power in the sub scanning direction substantially concentrates on the exit surface. The non-arcuated shape (curvature) of the exit surface in the main scanning direction is so determined as to make the magnification in the sub scanning direction uniform.