Abstract: A multibeam scanner capable of scanning an image forming area with constant beam amounts of laser beams. The multibeam scanner of the invention performs automatic power control (APC) on each of a plurality of beam emitting points one by one during corresponding time durations, respectively, in a non-image forming area. The laser beam emitted last among the plurality of laser beams is controlled to reach a predetermined beam detecting position within the corresponding time duration. Before scanning the image forming area, the multibeam scanner determines a scan start timing upon the detection of the laser beam emitted at the beam detecting position, which has been stabilized during APC. This arrangement allows the laser diode to avoid wasting time again and again, as rise time for stabilizing the laser beam for performing APC and for identifying the scan start timing, and to secure the time durations as long as possible.

Abstract: An image forming apparatus and a method of controlling turn-on of light source used therefor are capable of conducting stable image forming operation and maintaining high effective scanning rate while switching the rotation control of the polygonal motor between the internal control by the internal encoder of the motor and the external control by the horizontal synchronous signal outside of the motor. With the apparatus and method, the period of detecting the timing of start of the fast scanning (referred to as SOS period) is T when the driving motor rotates at a predetermined number of revolutions. T becomes shorter by T2 due to the switching from the internal control to the external control. During the shift from the internal control to the external control, the light source is turned on so that the period T1 from turning-on the light source for detecting the SOS timing to the detection of the SOS signal becomes longer than T2.

Abstract: Provided are a multi-beam scanning optical system capable of implementing high-quality printing in relatively simple structure and at high speed, and an image forming apparatus using it. The multi-beam scanning optical system has an incidence optical unit for guiding a plurality of beams emitted from a light source unit having a plurality of light-emitting regions spaced apart from each other in a main scanning direction, to a deflector; a scanning optical unit for focusing the plurality of beams deflected by the deflector, on a surface to be scanned; and a synchronism-detecting optical unit for converging part of the plurality of beams deflected by the deflector, via a return mirror on a slit surface by a lens section, thereafter guiding the beams to a synchronism detector, and controlling timing of a scan start position on the surface to be scanned, by use of a signal from the synchronism detector.

Abstract: An image recording apparatus includes a reference clock signal generating unit which generates a reference clock signal; a light beam generating unit which generates a plurality of light beams; a beam detect sensor which detects the plurality of generated light beams to output a plurality of light beam detection signals; an image clock signal. generating unit responding to the reference clock signal and the plurality of light beam detection signals to successively generate a plurality of image clock signals. These clock signals have the same period, and correspond to the plurality of light beam detection signals.

Abstract: Four beams are caused to scan a scanning surface in the main scanning direction in parallel. The beams expose the target area between two optical sensors, not the surface of a photosensitive drum, to produce correction data to correct shifts in the exposure positions of the four beams in the main scanning direction with an accuracy of less than a small fraction of one pixel. On the basis of the correction data, an actual image formation area is set on the photosensitive drum. This makes it possible to always control the relative exposure scanning position accurately even when the relationship between the main scanning positions of the light beams is unknown.

Abstract: Provided are a multi-beam scanning optical apparatus capable of realizing compactification of a synchronism-detecting optical system and high-accuracy synchronism detection based on prevention of spatial overlap between spots, and an image forming apparatus using it.

Abstract: A circuit for controlling scanning of light includes a detection-signal processing unit which generates a detection signal indicative of a timing at which a light beam hits a predetermined reference position, and a clock-generation unit which generates a clock signal in synchronism with the detection signal such that a timing of the clock signal is adjustable by the detection signal independently of a length of one clock cycle of the clock signal, wherein the clock signal synchronizes the light beam.

Abstract: Two sawtooth sensor patterns are combined so that they engage with each other. These sensor patterns are arranged so that a light beam passes sawtooth portions in a horizontal scan direction. A light beam's scan position is determined by integrating a difference between output signals from these sensor patterns. It is possible to provide a highly sensitive circuit for processing signals from the sensors and to improve detection accuracy for light beams.

Abstract: A synchronization signal detector receives a laser beam each time it is scanned in a main scanning direction, and detects a synchronization signal from the received laser beam. An external circuit or the like sets a binary value-determining level for this detector. The binary value-determining level is so determined as not to generate a signal arising from stray light. By this determination, a synchronization error, which is due to stray light, is prevented without adding manufacturing steps to prevent the stray light or without incurring an increase in the cost needed for structural components.

Abstract: A laser scanner is adapted to cause a laser beam to scan in the main-scanning direction by deflecting the laser beam by means of a deflecting optical system. A horizontal synchronizing signal is obtained by detecting the laser beam by means of a photodetector. Forced emission of laser beam is started after a predetermined time period since the detection of the laser beam, which predetermined time period is variable as a function of the rotary speed of the deflector section. With this arrangement, a horizontal synchronizing signal can be reliably detected if the rotary speed of the deflecting operation system fluctuates.

Abstract: Color electrophotographic printers having latent image positions synchronized with start-of-scan signals. A laser source projects a laser beam onto a multifaceted rotating polygon that sweeps that beam in a scan line across a moving photoreceptor. A start-of-scan detector produces start-of-scan signals when the laser beam is in position to write a scan line. A belt sensor produces belt signals when indicia on the photoreceptor passes a reference position. A controller receives the belt signals and the start-of-scan and then adjusts the photoreceptors rotational velocity such that the belt signals are an integral multiple of the start-of-scan signals. To reduce the impact of drive roller eccentricities on belt signal to start-of-scan signal timing, the perimeters of photoreceptor roller elements are sub-multiples of the photoreceptor length.

Abstract: A laser scanning system including a wavelength tunable laser generating and emitting a laser beam having tunable wavelengths, and at least one photonic crystal receiving the laser beam emitted from the wavelength tunable laser. The photonic crystal deflects the received laser beam, during propagation within the photonic crystal, at an angle depending on the wavelength of the laser beam, and emits the deflected laser beam at various angles of emission depending on the angle deflected in the photonic crystal to scan the laser beams over the surface area of a body to be scanned. Non-linearities found in the wavelength versus scanning beam position relation are corrected with position sensors provided at both ends, and in between positions, of the beam scanning range on the photosensitive drum. With this configuration of the position sensors, the non-linearities are corrected and also beam scanning with high precession becomes feasible.

Abstract: A method of setting a plurality of margins in an electrophotographic machine includes setting a top margin for a reference color black by establishing a first time delay between a vertical synchronization signal and a first line. A right margin or a left margin for the reference color black is set by establishing a second time delay between a horizontal synchronization signal and a start of printing. The other of the right margin and the left margin is set by adjusting a scan speed of a laser beam across a photoconductive element and adjusting a process speed in the cross-scan direction including the speed of the photoconductive element, image accumulation member, and print medium. A bottom margin is set by adjusting the process speed. The other three color planes, cyan, magenta and yellow are then registered or aligned to the reference color plane, black.

Abstract: In an image forming apparatus, a plurality of laser beams are emitted by a plurality of laser sources and are scanned onto a recording medium. The laser beams scanned are detected by two light-receiving elements juxtaposed in a main scanning direction. The output signals from the two light-receiving elements are compared so that a reference timing signal indicating that each of the scanned laser beams has reached a substantially middle position between the two light-receiving elements is outputted. The write operations of the plurality of laser sources in the main scanning direction are controlled to be synchronized on the basis of the respective reference timing signals.

Abstract: An optical scanning device for scanning plural surfaces including a plurality of laser light units each configured to emit a laser beam, a deflecting device configured to deflect the laser beams from the plurality laser light units to sweep a plurality of predetermined planes, respectively, and a scanning image forming optical unit configured to project the laser beams deflected by the deflecting device on the plural surfaces, respectively, to scan the plural surfaces with the laser beams. The scanning image forming optical unit includes a plurality of optical detecting devices configured to detect the laser beams and a first plurality of reflecting devices positioned to reflect at least two laser beams of the laser beams toward one of the plurality of optical detecting devices.

Abstract: This invention obtains an image forming apparatus and image forming method capable of achieving a simple, low-cost arrangement by controlling memory write-in/read-out similarly to image signal generation using a single beam even when an image is formed using a plurality of light beams. Write-in of a first light beam image signal in a memory A starts before a first light beam image signal for previous scanning is completely read out from the memory A. Write-in of a second light beam image signal in a memory B starts after a second light beam image signal for previous scanning is completely read out from the memory B.

Abstract: In a digital copying machine using a multi-beam optical system, a sensor pattern SH for sensing the power of each of the light beams a to d scanning the surface of a photosensitive drum and sensor patterns SB1 to SF1, SB2 to SF2 for sensing the passing positions of the beams are provided in a light beam position sensing unit. The sensor patterns SB1 to SF1, SB2 to SF2 are arranged linearly in the sub-scanning direction at intervals corresponding to two resolutions. The power of each light beam on the surface to be scanned is controlled so as to be in a specific range. Even when the light beams are scanned with different resolutions, they can be controlled with high accuracy so as to constantly have an ideal positional relationship between them. This always assures high picture quality.

Abstract: It is one object of the present invention to maintain a constant original document reading start position and a constant image forming start position for each color element, and to obtain a high quality color image with less variance in the image reproductivity of individual color elements.

Abstract: A multi-beam scanning optical system includes a light source having a plurality of light-emission points, an incident optical system for guiding a plurality of light beams emitted from the light source to a deflector, a scanning optical system for forming the plurality of light beams reflected/deflected by the deflector into images on a scanned surface, and a synchronization detection device in which a part of the plurality of light beams from the deflector are reflected at a predetermined angle in a sub-scanning cross-section by using a mirror to be scanned on a surface of a slit member and to be guided to a surface of a synchronization detection element via the slit member, and a timing at a scanning start position on the scanned surface is controlled by using a signal from the synchronization detection element. The slit member is positioned such that a plurality of light beams scanned on a surface of a slit opening are substantially vertically scanned on the slit opening.

Abstract: An optical scanning apparatus is capable of scanning a surface with a plurality of fluxes of light along a principal scanning direction. In the apparatus, a plurality of fluxes of light are emitted by a plurality of light sources arranged at intervals along an auxiliary scanning direction perpendicular to the principal scanning direction. The plurality of fluxes of light are lead to an optical deflector via an optical system for incident light and deflected by the optical deflector. Most part of the deflected fluxes of light are lead to the surface via an imaging optical system for scanning the surface, while small part of the deflected fluxes of light are lead to a photodetector to generate a synchronizing signal for controlling the timing of the scanning start of each of the fluxes of light.

Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.

Abstract: The present invention is an apparatus for digitally controlling the output of multiple laser diodes in a system that forms a plurality of scan lines in a Raster Output Scanning (ROS) system. Output of the laser diodes is digitally controlled by a multi-channel integrated circuit to eliminate propagation delay and linearity differences commonly found between single-channel modulation control devices.

Abstract: A Direct Digital Synthesis pixel clock generator for use in electrophotographic printers. A controller receives a start-of-scan signal and a facet 0 signal. In response, the controller sends a pre-stored frequency control word to a Direct Digital Synthesis Oscillator. The Direct Digital Synthesis Oscillator sends pulses at a frequency that depends on the frequency control word to a Digital Phase Shift Circuit. The controller also applies a sequence of delay profile words to the Digital Phase Shift Circuit. Each delay profile word causes the Digital Phase Shift Circuit to delay a contemporaneous pulse from the Direct Digital Synthesis Oscillator between 0° and 360° degrees, with the actual delay depending upon the delay profile word. The delay profile words are selected such that scan line pixels are “adjusted” in position. A phase-locked-loop circuit integrates and smoothes the frequency step changes.

Abstract: A signal is generated which is active only during an interval of taking one pulse of a series of output pulses of said synchronization detecting sensor, but is not active during an interval of taking more than one pulse thereof. Then, synchronization detection pulses are separated from the pulses output by the synchronization detecting sensor for the respective colors by using the thus-generated signal.

Abstract: A scanning sync-signal detecting circuit for a laser scanner is provided. The circuit prevents misdetections of a horizontal sync signal caused by stray beams and enables a precise detection of the sync signal, independent of the beam power. The scanner comprises a laser detector and a sync-detecting circuit. The sync-detecting circuit detects a proper beam for generating the sync signal in accordance with the duration of the signal from the detector for which the signal level is higher than a predetermined level. The sync-detecting circuit comprises a ramp generator, a comparator, and a sync signal generator. The level of the ramp signal corresponds to the signal duration from the detector. The signal level is compared with a predetermined boundary level, so that the output signal due to the proper beam is detected.

Abstract: In an optical scanning apparatus used in an image forming apparatus for scanning a plurality of optical beams on photosensitive members and for synthesizing a plurality of images formed on the photosensitive members to output a synthesized image as a single image, positional shifts occurred in the plural images can be corrected in a simple arrangement and in low cost.

Abstract: An electrophotographic imaging device uses a transition placement device to position transitions in a stream of video data. A rasterizer included in the electrophotographic imaging device generates pixel data bytes based upon data received from a computer defining an image. A converter generates codes specifying positions of transitions within a pixel time period corresponding to a pixel data byte. The transition placement device includes a phase measuring device to measure a timing offset between an active edge of a beam detect signal and a rising edge of a reference clock. A transition adjustment device adjusts the positions of the transitions specified by the codes relative to the rising edge of the reference clock using the timing offset. Transition generation logic generates the transitions for the stream of video data using the adjusted transition positions received from the transition adjustment device.

Abstract: To provide a laser scanning apparatus, which can suppress the unnecessary emission of a laser beam for a photosensitive drum, can prevent the degradation of the photosensitive drum, and can prolong the life time of a laser, with using simple configuration, an image forming apparatus using this laser scanning apparatus, and a method for starting the laser scanning apparatus. A laser scanning apparatus performing exposure with a laser beam predicts a time elapsing until completion of start on the basis of initial start conditions, shuts off the laser beam during the time predicted, emits a laser beam after the time predicted elapses, and detects completion of start.

Abstract: A system is provided for rendering an output image on an image transfer surface using multiple optical scan paths in an image rendering device. The system includes a plurality of lasers, a plurality of scan time detectors, and processing circuitry. Each of the lasers is configured to generate an optical scan path on the surface. Each scan time detector is associated with a corresponding laser and is operative to measure scan time of the laser along the respective optical scan path. The processing circuitry communicates with each scan time detector and is operative to generate a video signal having a video frequency associated with the scan time detected for the respective laser. A method is also provided.

Abstract: An optical writing apparatus including a semiconductor laser having plural light emitting elements and a single light-receiving element and plural semiconductor laser drive controlling devices. The plural light emitting elements in the semiconductor laser array are driven such that an optical writing operation at a same time per each of plural lines is performed. A commonly used LD drive controlling circuit drives the LD array. An output timing-determining device outputs a switch changing-over signal to either one of respective changing-over switches in a changing-over switch circuit. After an operational delay time of the changing-over switch elapses, an APC signal is output to an APC control section of the LD drive controlling circuit connected to a negative feedback loop formed by a changing-over operation of the changing-over switch circuit. After the completion of the APC operation, the outputting of the switch changing-over signal to the changing-over switch is stopped.

Abstract: A light-scanning optical system comprises a light source, a first optical system, a light deflector having a deflection surface, a second optical system, a photodetector and a luminous flux delimiting member. A luminous flux emitted from the light source is trimmed and imaged as a linear luminous flux extending in the main scanning direction by the first optical system. The deflection surface of the deflector is arranged near the imaging position of the first optical system so that it reflects and deflects the linear luminous flux for scanning operation. The deflected luminous flux is then imaged on the plane to be scanned by the second optical system that establishes a substantially conjugate relationship between the deflection surface and the plane to be scanned.

Abstract: In this invention, a precise multi-beam control process can be effected while suppressing an influence due to the drift of a galvanomirror by effecting the multi-beam position control process during the copying operation, that is, by repeatedly effecting the sub-scanning position control process and main scanning position control process. Therefore, an image can be prevented from being deviated at the front and rear end portions of one sheet of paper.

Abstract: A multi-beam scanning optical system is provided with a light source unit emitting a plurality of beams. The beams are incident on a polygonal mirror, and deflected thereby to scan in a predetermined scanning range. The scanning beam is incident an f&thgr; lens system. The f&thgr; lens system includes a plurality of lenses, and all the beams pass at least one of the plurality of lenses included in the f&thgr; lens system. The lens, which all the beams pass through, is formed as a single lens element made of single material. Further, the lens contributes to convergence of the beams in the main scanning direction.

Abstract: In a multi-beam scanning device including a laser diode array having three or more light emitting points, the interval Pi between one of the three or more light emitting points and the adjacent light emitting point is set so as to be not greater than the minimum recording interval Pi′ of image information to be recorded on a recording medium. In addition, the three or more light emitting points are arranged such that the corresponding laser beam spots formed on the recording medium are arranged in a line or substantially in a line in the sub-scanning direction B. Thereby recording speed and recording density can be increased.

Abstract: An image forming apparatus includes a light beam generating and modulating device which generates and modulates a light beam in accordance with an image signal, a light beam deflecting device which deflects the modulated light beam and scans an image carrier so as to form an image.

Abstract: An optical scanning apparatus has an incident optical system for causing a light beam from a light source to be obliquely incident in a sub-scanning cross-section on a deflecting surface of an optical deflector, and an imaging optical system for forming, on a scanned surface, an image of the light beam deflected by the deflecting surface.

Abstract: A multibeam light source for use in information recording, including a semiconductor laser array provided with a plurality of light emitting points in a single package, in which the plurality of light emitting points are positioned in linear relationship to one another and have an equidistant pitch so as to respectively emit laser beams to be simultaneously scanned over a recording substrate. The position of the semiconductor laser array is adjustable so as to satisfy the relation &thgr;≦tan−1{1/(n−1)}, where the angle &thgr; is defined by two straight lines, the one drawn perpendicular to the primary scanning direction on an image recording substrate and the other drawn through respective centers of the first and n-th laser beam spots formed on the image recording substrate by projecting laser beams emitted respectively from the plurality of light emitting points.

Abstract: An optical scanning apparatus includes a plurality of light sources which emit first and second beams. First and second coupling lens units respectively couple the first and second beams emitted by the plurality of light sources. A rotary deflector which has pairs of mutually-opposite reflection surfaces and deflects the first beam in a first direction by one of the reflection surfaces and deflects the second beam in a second direction opposite to the first direction, by another of the reflection surfaces. First and second imaging units scan an image surface of a photoconductive medium along a first half of a main scanning line by focusing and deflecting the deflected first beam onto the image surface, and scan the image surface along a second half of the main scanning line by focusing and deflecting the deflected second beam onto the image surface, such that the first and second halves form a substantially straight scanning line on the image surface when the rotary deflector is rotated.

Abstract: When the image-forming modes are switched over, the difference between the scan speeds of image-forming modes before and after the mode switching is checked. If the difference is not less than a predetermined set value, the adjustment of a laser beam is executed first, and then image formation is started. If the difference between the scan speeds of image-forming modes before and after the mode switching is less than the predetermined set value, the image formation is started immediately without making adjustment of the laser beam.

Abstract: An image forming apparatus containing a divisional scanning type optical scanner. In the apparatus, if displacement of one line in a subscanning direction occurs in a joint of image formation areas, light sources are controlled so as to modulate and emit light beams based on image data of the scanning line shifted one line at the same point of time. If displacement of 0.5 pixels in a main scanning direction occurs in a joint of image formation areas, the emission start timing of one light beam is shifted by the scanning time as long as 0.5 pixels with respect to the emission start timing of the other light beam, thereby correcting the displacement amount in the main scanning direction.

Abstract: A method and apparatus for forming an image reduce the processing load on a video controller. A CPU causes a counter to start counting the optical beam detection signals of a photodiode in accordance with a signal which indicates the leading edge of a sheet of recording paper received from a TOP sensor. Comparators compare the count value issued from the counter with the values set by the CPU at registers. Based on the comparison result, an F/F sets Q output. Thus, a BD signal is issued through a gate during a period specified by the values set at the registers. The use of the BD signal reduces the processing load on the video controller which generates and transfers an image signal.

Abstract: An image formation apparatus which records an image on a recording medium is provided. The apparatus has a recording element array head on which plural recording chips are arranged, plural recording elements being arrayed on the recording chip, a reference clock generation unit for generating a reference clock, a main scan sync signal generation unit for generating a main scan sync signal by dividing the reference clock into 2n1 (n1: positive number) parts, an input unit for raster inputting image data for one line in synchronism with the main scan sync signal, a drive clock generation unit for generating a drive clock by dividing the reference clock into 2n2 (n2: positive number) parts and a drive unit for driving the recording chips in synchronism with the drive clock.

Abstract: A method and apparatus for signal phase alignment. A pulse is produced and a reference clock signal having a first frequency with one or more clock edges is produced. An alignment clock signal is generated having the first frequency aligned with the pulse. The first frequency of the alignment clock signal is then realigned with the pulse. The alignment clock signal is generated using the pulse and aligning one of the clock edges of the reference clock signal with the pulse edge. The alignment clock signal is realigned using a plurality of delayed clock signals based on the reference clock signal. Each of the delayed clock signals has one or more edges. The plurality of delayed clock signals are latched based on the pulse and the delayed clock signal having an edge nearest to the pulse is selected.

Abstract: Four beams are caused to scan a scanning surface in the main scanning direction in parallel. The beams expose the target area between two optical sensors, not the surface of a photosensitive drum, to produce correction data to correct shifts in the exposure positions of the four beams in the main scanning direction with an accuracy of less than a small fraction of one pixel. On the basis of the correction data, an actual image formation area is set on the photosensitive drum. This makes it possible to always control the relative exposure scanning position accurately even when the relationship between the main scanning positions of the light beams is unknown.

Abstract: In a digital copying machine using a multi-beam optical system, a light beam position detector situated on a line extended from the surface of a photosensitive drum detects the passing position of each light beam scanned by a polygon mirror rotated by a polygon motor. A CPU calculates control amounts for galvanomirrors by using a beam position detector output processor, on the basis of the detection result of the beam position detector. Based on the calculated control amounts, galvanomirror drive circuits drive the galvanomirrors, thereby to control the positions of the beams in a sub-scan direction. The passing positions of the beams can be precisely detected with no special precision in assembling the optical system. In addition, the positions of the beams in the sub-scan direction can be controlled at predetermined positions, even if some change occurs in the structure of the optical system due to a variation in ambience or a variation with the passing of time.

Abstract: An embodiment of an edge placement device is supplied with transition data to generate transitions during a pixel time period corresponding to the transition data. The transition data is supplied by pulse code logic that converts pixel data to the transition data. The embodiment of an edge placement device includes first edge placement logic coupled to taps from a first clock delay chain and second edge placement logic coupled to taps of a second clock phase delay chain. Also included is a phase splitter that generate a first and a second clock phase coupled, respectively, to the first and the second clock delay chain from a clock corresponding to a pixel time period. The first and the second clock phase have rising edges on alternate cycles of the clock. The first and the second edge placement logic each include a plurality of D flip flops.

Abstract: An image forming apparatus records an image on a recording medium by scanning the recording medium with a plurality of beams modulated according to individual information signals. A beam detect device detects the plurality of beams arriving at respective predetermined positions and generates a plurality of beam detect signals corresponding to the plurality of beams, respectively, and a beam detect signals separating device separates the plurality of beam detect signals into individual beam detect signals. An image formation start timing for each beam is controlled according to each beam detect signal separated from others by the beam detect signals separating device.

Abstract: A method and system are disclosed for improving performance of adjustable printer clock signals in an electrophotographic device. A source clock signal is output having a source frequency. A first clock signal is output having a first frequency. The first frequency is substantially related to the source frequency by a ratio of n1:m1. An alignment signal is generated for adjusting a first printer clock signal with respect to a second printer clock signal. In response to the first clock signal and the alignment signal, the first printer clock signal is output having a first printer frequency. The first printer frequency is substantially related to the source clock frequency by a ratio of n1n2:m1m2.

Abstract: A photodiode is positioned outside an image recording region and receives light from a light source portion prior to image recording processing. When the photodiode detects light at the time of the first main scan, the pulse number of a stepping motor is reset, 0, and thereafter, the pulse number is used to control the driving of the stepping motor. For this reason, an output timing of an image signal in the second and subsequent main scan operations does not depend on the detection of light by the photodiode and allows output of an image signal at a predetermined pulse number. The scan operation based on the control of the pulse number is effected for each image, and at the scan start time of a subsequent image, the pulse number is reset again when light is detected by the photodiode. Accordingly, it is possible to eliminate inconsistency of the start time of each main scan, which is caused by a variation in the time of detection by a sensor for controlling a scan start timing.

Abstract: The present invention has been made for the purpose of obtaining an optical apparatus which avoids the necessity for changing a control unit for appropriate control of a light source or making a modification to the control unit even when the type and specifications of the optical apparatus are changed, whereby costs for designing the control unit may be reduced. In the case where a comparative table stores therein LEND signal times and data starting times respectively corresponding SYNC signal periods of three apparatuses of different types, a CPU searches for a SYNC signal period coincident with the measured SYNC signal period from among the SYNC signal periods which are stored in the comparative table, and executes control of signals for an optical unit by using the obtained LEND signal time and data starting time corresponding to the searched SYNC signal period.