Abstract: A lens mirror array includes a plurality of transparent optical elements integrally connected to each other in one direction. Each of the optical elements includes: an incidence side lens surface on which light is incident; an exit side lens surface through which incident light exits; and a flange portion having a surface continuous to the incidence side lens surface. The surface of the flange portion is arranged at an angle at which unnecessary light incident on the flange portion is guided to a position deviating from an slit, the slit allowing transmission of effective light in light that exits through the exit side lens surface.
Abstract: A document reading apparatus including: a detector configured to detect presence of a document on a document tray; a conveyance unit configured to convey the document; a reading unit configured to read the document conveyed by the conveyance unit at a first position; and a reference member. When the detector detects the presence of a document, the reading unit reads the reference member to determine a shading correction value while being moved from a second position to a third position located between the first position and the second position. When the shading correction value is to be determined again in a period from when the shading correction value is determined until when a receiver receives an instruction to start reading, the reading unit reads the reference member while being moved from the second position toward the first position after having been moved from the third position to the second position.
Abstract: An image scanning device includes a linear light source to illuminate a linear illumination position of a scan target with light, a lens body, and a sensor. The linear light source includes a light guide, a scatterer, an emitter, a stepped portion, and a light-shielding member. The stepped portion is formed, from the end surface of the transparent body along the main scan direction, on a side of the light guide that is opposite to the illumination position side of the light guide. The light-shielding member covers a portion of the emitter of the light guide, the portion including the end surface of the transparent body, and extends beyond the stepped portion in the main scan direction and has an end portion that is located out of a scan range of the sensor in the main scan direction.
Abstract: Provided is an image reading apparatus configured to avoid unnecessarily performing shading correction processing. The image reading apparatus detects whether or not an original is placed on an original tray when detecting an open state of an ADF and then detecting a closed state thereof. In a case where the original is placed on the original tray, the image reading apparatus performs shading correction for flow reading, and in a case where no original is placed on the original tray, the image reading apparatus performs shading correction for platen cover reading.
Abstract: An improved optical encoder uses an optical pick-up unit that provides for degrees of freedom in the tracking and focus axes that are unavailable in conventional optical encoders thereby improving the encoders' performance. In an embodiment the encoder employs an optical disc marked with pits and lands which may be arranged in a spiral pattern. The optical disc is mounted on the shaft whose motion is to be monitored by the optical encoder. The encoder may be arranged to read the markings on the optical disc using the three-beam pickup method.
Abstract: This invention relates to an apparatus (1) for carrying out a non-destructive inspection on a wooden board (9) or a similar object. The apparatus (1) comprises a movement system (3) comprising at least two chains or belts (32) that are at a distance from one another and substantially parallel to each other. The chains or belts (32) are slidable parallel to a movement path (30) and are and intended to support the wooden board (9). The apparatus (1) also comprises a non-destructive inspection station (2) that is positioned on the movement path (30), for carrying out a non-destructive inspection on the wooden board (9) that is supported by the chains or belts (32). The non-destructive inspection station (2) comprises at least one operating component (22) that is positioned on the same side as the chains or belts (32) and emits or receives a signal or an image, with an emission or reception field (220) that faces towards a region between two chains or belts (32).
March 14, 2017
Date of Patent:
August 18, 2020
Egon Eisner, Herbert Zambra, Konrad Tschurtschenthaler, Johann Thaler
Abstract: An illuminating device capable of stably illuminating an irradiated object such as a document while suppressing light loss with a simply structure is provided. An LED array and a reflective plate are disposed sandwiching a slit (St) through which light reflected by a document MS passes and a light-guiding member is disposed on the side of the LED array. The light-guiding member includes a direct emission unit disposed between an illumination range y centered on a document reading position and the LED array and an indirect emission unit disposed between the reflective plate and the LED array, a light incidence face of the direct emission unit and a light incidence face of the indirect emission unit are disposed at mutually different position around the LED array, and the LED array is disposed on a side of an interior angle formed by the light incidence faces.
Abstract: A reading module has a light source, an optical system having a mirror array and an aperture stop portion, a sensor in which a plurality of image regions where the image light is converted into an electrical signal are arranged; a housing; and a light-shielding wall shielding stray light striking the image regions. In the mirror array, a plurality of reflective mirrors whose reflection surfaces are aspherical concave surfaces are coupled together in an array in the main scanning direction. The optical system is fixed to on the case housing at one point in the main scanning direction, and the light shielding walls are arranged at a positions displaced deviated by a predetermined amount from boundaries between the image regions in the direction opposite to the fixed side of the optical system.
Abstract: In one example, an apparatus includes a transparent platen to receive a document to be scanned. The transparent platen includes a scan line, an ingress edge positioned prior to the scan line in the document path, and a chamfered egress edge positioned subsequent to the document path. A light source is positioned to illuminate the document with light while the document passes across the scan line, and a focusing mechanism is positioned to focus a portion of the light that is reflected by the document onto a sensor that senses the portion of the light.
September 8, 2016
Date of Patent:
April 21, 2020
Hewlett-Packard Development Company, L.P.
Eric Andersen, Ryan M Smith, Shannon Lai, Jennifer Waskow
Abstract: A setting device sets a print page to be clear-coated. When print data is obtained, the setting device displays a preview of a print page image represented by the print data (step S1040). The setting device further receives a designation for a print page image of which preview is displayed, and sets a print page corresponding to the print page image of which designation has been received as a print page to be clear-coated (step S1050).
Abstract: An image reading device includes a housing that is provided with a contact glass, a document cover, an illumination unit that is received in the housing, and a document size detection unit that performs a document size detection operation for detecting a size of a document by using light irradiated toward the document on the contact glass from the illumination unit when the document cover is switched to a closed state. The illumination unit includes a light guide body extending in a front and rear direction of the housing, a first light source that is disposed at a front side of the light guide body and emits incident light to the light guide body toward a rear side, and a second light source that is disposed at a rear side of the light guide body. In the document size detection operation, only the first light source is lighted.
Abstract: Methods and systems for describing a camera radiometrically, in terms of camera response function and vignetting, and in terms of color, suitable for non-uniform illumination set-ups. It estimates the camera response function and the camera color mapping from a single image of a generic scene with two albedos. With a second same-pose image with a different intensity of the near-light the vignetting is also estimated. The camera response function calibration involves the segmentation of the two albedos, the definition of the system of equations based on the assumption that can be made about the image formation process, and the actual estimation. For the modelling the vignetting there are three steps: computing the albedo-normalized irradiance, finding points of equal vignetting, when needed, and estimation.
April 13, 2016
Date of Patent:
December 10, 2019
Universidade de Coimbra
Pedro Miguel Cerveira Rodrigues, João Pedro de Almeida Barreto
Abstract: In an image forming apparatus that executes exposure for discharging a photoconductive drum by a light emitting unit by which an electrostatic latent image is formed, a duty ratio of a drive signal for a driving unit that exposes the photoconductive drum for performing discharging of the photoconductive drum is set to be 100%, and it is thereby possible to suppress generation of radiation noise resulting from the drive signal for the discharging.
Abstract: An image forming apparatus includes a display, a human detection sensor, and a CPU. If the CPU determines that there is a person in a certain area with the display in an off state, the display enters a first on state in accordance with an instruction from the CPU. If the CPU determines that the image forming apparatus has been operated, the display enters a second on state.
Abstract: There is provided an image reading device which has an operation part configured to receive an operation to select one of a first scan function of treating image data of a plurality of originals read by a reader as one file and a second scan function of treating image data of one original read by the reader as one file. When the operation part receives the operation to select the second scan function, the reader is moved toward a waiting position opposite to the reading end position with respect to the reading start position after completion of the reading process. In response to detection of opening of the cover before the reader reaches the waiting position, a determining process is not executed, while the determining process is executed when opening of the cover is not detected before the reader reaches the waiting position.
Abstract: Provided is a reading module including a light source, an optical system, and a sensor. The optical system images reflected light of light emitted from the light source to the document, as image light. The sensor converts the imaged image light into an electric signal. The optical system includes a mirror array in which a plurality of reflection mirrors are connected, and a plurality of aperture stops. Neighboring reflection mirrors reflect light at different angles viewed from the main scanning direction.
Abstract: Provided is a scanner having sixteen or fewer sensor chips capable of scanning an A4 document; an optical unit that reduces and focuses an image of an A4 document on the sensor chips; and a generator that synthesizes images of the A4 document read by the sensor chips, and generates image data.
Abstract: A reading module has a light source, an optical system imaging, as image light, reflected light of light radiated from the light source to a document, a sensor where a plurality of imaging regions for converting the image light imaged by the optical system into an electrical signal are arranged next to each other in the main scanning direction, and a housing the light source, the optical system, and the sensor. The optical system has a mirror array where a plurality of reflection mirrors whose reflection surfaces are aspherical concave surfaces are coupled together in an array in the main scanning direction, and an aperture stop portion adjusting the amount of the image light reflected from the reflection mirror. The amount of the image light striking the reflection mirror is increasingly small from opposite end parts of the reflection mirror toward its central part in the main scanning direction.
Abstract: An image forming apparatus includes an image reading device; an image forming device including a photoconductor, a charger, an exposure device including a light-emitting element, a memory to store a first correction value for correction a light emission amount of the light-emitting element, and a driver to drive the light-emitting element, a developing device, a transfer device, and a fixing device. The image forming apparatus further includes a processor to calculate a second correction value for correcting the light emission amount, based on density data of image data of a predetermined pattern on a recording medium; calculate a third correction value for correcting the light emission amount, based on the first correction value and the second correction value; and determine, before calculating the third correction value, whether placement of the recording medium on the reading table is correct based on the density data.
Abstract: An image forming system includes a light emitting device, a controller, an image forming device, an acquiring device, a calculator, and a storage device. The controller corrects an amount of light, which is outputted from the light emitting device, based on a first correction value stored in the storage device. The image forming device forms a test image with the amount of light corrected based on the first correction value. The acquiring device acquires density information indicating a characteristic of density of the test image. The calculator calculates a second correction value based on the density information and calculates a third correction value based on the first correction value and the second correction value. The controller corrects the amount of light based on the third correction value. The image forming device forms a target image with the amount of light corrected based on the third correction value.
Abstract: An image reading apparatus includes: N sensor chips arranged in a first direction and each including a plurality of image pickup elements arranged in the first direction; N optical systems that form, on the N sensor chips, reduced-size images of N reading ranges arranged in the first direction on a document; and an image processing section that uses image data of overlap regions to obtain positions of the overlap regions, obtains, based on the positions and predetermined synthesis reference positions in the overlap regions, magnifications of read images and synthesis positions, performs image processing of correcting the magnifications in the first direction of the image data of the N reading ranges, and combines the image data of the N reading ranges subjected to the image processing, thereby generating synthesized image data.
Abstract: A reading module has a light source, an optical system, and a sensor. The optical system images, as image light, reflected light of light radiated from the light source to a document. In the sensor, the image light imaged by the optical system is converted into an electrical signal. The optical system has a mirror array and an aperture stop portion. In the mirror array, reflection mirrors are coupled together in an array in the main scanning direction. The aperture stop portion has a first aperture adjusting the amount of the image light reflected from a reflection mirror and a second aperture shielding stray light entering the first aperture from an adjacent reflection mirror. Between the first and second apertures, a reflection reduction mechanism is provided that reduces reflection, toward the first aperture, of light other than the image light traveling from the second to first aperture.
Abstract: A reading module has a light source, an optical system imaging, as image light, reflected light of the light radiated from the light source to the document, and a sensor converting the image light imaged by the optical system into an electrical signal. The optical system has a mirror array in which reflection mirrors are coupled together in an array in the main scanning direction and an aperture stop portion having a first aperture adjusting the amount of image light reflected from a reflection mirror and a second aperture shielding stray light that enters the first aperture from an adjacent reflection mirror. The second aperture is arranged at such a position as to be able to shield stray light passing through a boundary between the reflection mirrors and the center of the first aperture when the mirror array contracts to the maximum extent in the main scanning direction.
Abstract: An image reading device has a reading module including a light source, an optical system having a mirror array where reflection mirrors are coupled together in the main scanning direction and an aperture stop portion, a sensor where imaging regions for converting the image light imaged by the optical system into an electrical signal are arranged, and a housing, and has a reference drawing pattern determining connection positions between the imaging regions. The reference drawing pattern is composed of a plurality of pixel cut lines arranged to correspond to boundary lines between the reflection mirrors. The optical system is fixed on the housing at one point in the main scanning direction, and the pixel cut lines are arranged such that their distances from the boundary lines in the main scanning direction increase the farther away from the fixed position of the optical system in the main scanning direction.
Abstract: According to an embodiment, a detection apparatus for detecting a decoloration ink image includes an image reading unit, a decoloration unit, and a controller. The controller acquires image data using the image reading unit before decoloration that is the image data on the sheet before decoloration processing is executed by the decoloration unit. In addition, the controller determines whether or not there is a difference between the image data to be decolored and the decolored image data, thereby determining whether or not the decoloration ink is used in the sheet.
Abstract: A system and method are described for enhancing readability of document images by operating on each document individually. Monochromatic light sources operating at different wavelengths of light can be used to obtain greyscale images. The greyscale images can then be used in any desired image enhancement algorithm. In one example algorithm, an automated method removes image background noise and improves sharpness of the scripts and characters using edge detection and local color contrast computation.
December 19, 2016
Date of Patent:
December 18, 2018
Ophir Frieder, Gideon Frieder, Jon Parker
Abstract: An apparatus for securing a camera housing (100) having a central axis (102) to a windshield (22) includes a bracket (20). The bracket (20) has a central axis (30) and extends from a first end (32) to a second end (34). A plurality of centering members (72) on the first end (32) of the bracket (20) is configured to engage the camera housing (100) to align the central axis (102) with the central axis (30). A plurality of locking members (90, 91) on the second end (34) of the bracket (20) is configured to form a snap-fit connection with the camera housing (100) to fasten the bracket (20) to the camera housing (100). The locking members (90, 91) are positioned on opposite sides of the central axis (30) of the bracket (20) with at least one locking member (90, 91) extending at an angle less than 90° to the central axis (30).
Abstract: An image reading apparatus includes an illumination unit that illuminates light on an image surface of a sheet, and a photoelectric conversion element that converts reflected light from the sheet illuminated by the illumination unit into an electric signal. The illumination unit includes a circuit board including a light emitting element, and a light guide that guides light, emitted from the light emitting element, to a sheet read surface. In the image reading apparatus, the light guide includes a positioning surface that abuts against a first surface of the circuit board and that performs positioning of the light guide and the circuit board, and a pressing portion that abuts against a second surface of the circuit board on an opposite side of the first surface and that presses the circuit board against the positioning surface.
Abstract: An image reading device has a motor, an optical sensor (a light emitting portion, a light receiving portion), a carriage, a motor, a moving portion for rotating a belt, a pulse generating gear provided with a plurality of light shielding teeth along its circumference, and a control portion. The light shielding teeth of the pulse generating gear pass through a gap between the light emitting portion and the light receiving portion. First and second widths are set such that the movement amount of the pulse generating gear resulting from the motor rotating one step is equal to or larger than both the width of each of the light shielding teeth (first width) and the width of the interval between adjacent light shielding teeth (second width). The control portion recognizes when, during standby of the carriage, the level of an output signal changes.
Abstract: A reading apparatus that reads a sheet includes: a first light emitting diode (LED) configured to emit light with a specific wavelength; a light emitting element including a second LED configured to emit light with the specific wavelength and a phosphor configured to be excited by the light emitted from the second LED; a line sensor configured to generate a reference signal according to a quantity of received light emitted from the first LED and reflected off the sheet, and also generate an image signal according to a quantity of received light emitted from the light emitting element and reflected off the sheet; and a controller configured to generate an image representing the sheet from a differential result obtained by removing a component corresponding to the reference signal from the image signal.
Abstract: An image forming apparatus includes a photoconductor, a light source, an optical scanning device, an image bearer, an image density sensor, an image processing circuit, and a light source driver. The plurality of images are formed with a plurality of light intensities and a plurality of image area rates on the image bearer. The image density sensor detects a plurality of image densities of the plurality of images at a plurality of positions in a main scanning direction. The image processing circuit determines a light intensity correction value to correct an image density of a target image in the main scanning direction based on the plurality of light intensities, image area rates, image densities, and positions, and the image area rate of the target image, and outputs a control signal to adjust a light intensity. The light source driver adjusts the light intensity based on the control signal.
Abstract: Color calibration of color image rendering devices, such as large color displays, which operate by either projection or emission of images, utilize internal color measurement instrument or external color measurement modules locatable on a wall or speaker. A dual use camera is provided for a portable or laptop computer, or a cellular phone, handset, personal digital assistant or other handheld device with a digital camera, in which one of the camera or a display is movable with respect to the other to enable the camera in a first mode to capture images of the display for enabling calibration of the display, and in a second mode for capturing image other than of the display. The displays may represent rendering devices for enabling virtual proofing in a network, or may be part of stand-alone systems and apparatuses for color calibration.
Abstract: A light guide body (2) includes a light guide main body (21), a band region (4), and radial microstructures (5). The light guide main body (21) is columnar, and light enters the light guide main body (21) from at least one end portion (3). The band region (4) is formed extending in the lengthwise direction of a portion of a circumferential surface of the light guide main body (21). The radial microstructures (5) are arranged in the band region (4) and are formed as microstructures that each have protruding parts extending radially in at least three directions in a band region portion from a reference point.
Abstract: Light is emitted on one side of a paper sheet 100, which is being transported on a transport path, from a first light source 11, and light is emitted on other side of the paper sheet 100 from a second light source 21 and a fourth light source 22. A first light receiving sensor 14 receives a first reflected light, which is the light emitted by the first light source 11 and reflected from the one side of the paper sheet 100. A second light receiving sensor 24 receives a second reflected light, which is the light emitted by the second light source 21 and the fourth light source 22 and reflected from the other side of the paper sheet 100, and receives a transmitted light that is the light emitted by the first light source 11 and that has passed through the paper sheet 100.
Abstract: An image forming apparatus includes an image forming section; a density detection section configured to detect the density of toner image formed on an image bearing member in a sub scanning direction; and a density-unevenness correction section configured to calculate a first correction amount based on the detection result of the density detection section and calculate a second correction amount different from the first correction amount in phase.
Abstract: A system may obtain identification information for a user for obtaining a form of access using universal enrollment. The system may obtain a digital certificate associated with the identification information, the digital certificate including a public key of a public key, private key pair and the public key and the private key of the public key, private key pair being generated using first biometric information of the user obtained during the universal enrollment. The system may obtain second biometric information. The system may generate a second private key using the second biometric information. The system may determine whether the second private key matches the public key included in the digital certificate. The system may provide the form of access based on the second private key matching the public key included in the digital certificate.
June 26, 2015
Date of Patent:
January 16, 2018
Verizon Patent and Licensing Inc.
Manuel Enrique Caceres, Yuk Lun Li, Mauricio Pati Caldeira de Andrada
Abstract: An image is read from a recording medium via first and second optical imaging systems disposed such that respective reading regions partially overlap each other in a principal scanning direction on a reading surface. A sum of distances over which first and second images captured by the first and second optical imaging systems, respectively, are displaced in the principal scanning direction with respect to a reference point included in a region in which the reading regions overlap each other is calculated. First and second distances, over which the first and second images are displaced in the principal scanning direction, respectively, are calculated using the sum and first and second reading angles at which the first and second optical imaging systems, respectively, read the reference point. Positions of the first image and the second image in the principal scanning direction are corrected using the first distance and the second distance, respectively.
Abstract: An image forming apparatus which is configured to expose a photosensitive member to light beams emitted from a plurality of light emitting elements, generates a plurality of BD signals by a plurality of laser light beams, and controls timings at which the plurality of light emitting elements emits the light beams based on a difference between timings at which the BD signals are generated.
Abstract: An image reading system is configured by integrally assembling a flatbed scanner apparatus and a sheet-fed scanner apparatus using a separate component, a connection unit. A circuit substrate for a power source system and a communication system is disposed in the connection unit. The circuit substrate includes a power source input connector to which power is input, a power divider that divides power input from the power source input connector into plural types, and a power source output connector and a communication connector that output each power divided by the power divider to each scanner apparatus.
Abstract: An adjustment includes a first current adjustment for adjusting a first current Idrv by supplying a superimposed current of the first current Idrv and a second current Ib to an LD 101a, and a second current adjustment for adjusting the second current Ib by supplying the second current Ib to the LD 101a without supplying the first current Idrv thereto. Upon reception of an image forming instruction, a control unit performs adjustment in order of the second current adjustment for the first time, the first current adjustment for the first time, the second current adjustment for the second time, and the first current adjustment for the second time. An execution period of the second current adjustment for the first time is longer than an execution period of the second current adjustment for the second time.
Abstract: In a case of changing a first light quantity to a second light quantity which is smaller than the first light quantity, a light quantity changing unit changes a light quantity to a third light quantity, which is smaller than the first light quantity and larger than the second light quantity, before changing the light quantity to the second light quantity, and a third light quantity is a light quantity with which the signal is able to be output in a state where a first threshold is set.
Abstract: A light guide includes an incident surface provided at least at an end portion of the light guide in a longitudinal direction, and receiving light from a light source, an output surface constituting a part of an outer peripheral surface, and outputting the light introduced through the incident surface, a reflecting surface extending along the optical axis so as to oppose the output surface, and including a plurality of reflection patterns that reflect the introduced light toward the output surface, and a reflecting plate opposed to a region in the outer peripheral surface other than the incident surface, the output surface, and the reflecting surface, and reflecting the light from the light source. The outer peripheral surface includes a sloped portion formed so as to come closer to the reflecting plate in a direction away from the incident surface in the longitudinal direction.
Abstract: A light irradiator includes a light source and a light guide to guide a light flux from the light source to an illumination area. The light guide has an incident surface, an emission surface and two side surfaces. The emission surface is located apart from a reading optical axis with an inclination relative to the reading optical axis. The following relations are satisfied: S1(x)?S2(x) S1(L)>S2(L) wherein S1 represents a divided cross-sectional area near the reading optical axis and S2 represents a divided cross-sectional area far from the reading optical axis when a virtual cross-sectional area S parallel to the incident surface of the light guide is divided by a plane passing the center of the incident surface, formed by a direction perpendicular thereto and the incident surface and the main scanning direction; S (x) represents a virtual cross-sectional area distant from the incident surface of the light guide by x; L is a distance from the incident surface to the emission surface; and 0?x<L.
Abstract: A light guide for use in an image reading apparatus. The light guide extends in a predetermined direction and includes: a reflecting surface being parallel to the predetermined direction; an emitting surface; and a prism configured to reflect light to the emitting surface. The prism includes a plurality of asperities formed on the reflecting surface. When viewed from a first direction orthogonal to the reflecting surface, at least one of the plurality of asperities includes a portion parallel to a predetermined curve or a predetermined straight line inclined from a second direction orthogonal to the predetermined direction.
Abstract: A method of matching medical images according to user-defined matches rules. In one embodiment, the matched medical images are displayed according user-defined display rules such that the matched medical images may be visually compared in manner that is suitable to the viewer's viewing preferences.
April 3, 2014
Date of Patent:
January 10, 2017
D.R. Systems, Inc.
Murray A. Reicher, Evan K. Fram, Steven M. Greim, John J. Schumacher
Abstract: The invention relates to a measuring device (1), in particular a laser scanner for optically scanning and measuring an environment. The measuring device (1) comprises a rotatably mounted measuring head (2) and a rotation unit (10) mounted therein and having a rotatably mounted rotation body (20), wherein a targeting element (70) for sighting a target point is integrated into the rotation body (20), said targeting element comprising an opening (70?) passing through the rotation body (20).
Abstract: An information processing apparatus includes a plurality of modules and a change processing portion. The modules are capable of executing data processing on data stored in a memory connected thereto via a bus. The change processing portion is configured to change a frequency of an operation clock signal to be supplied to each module, in accordance with either one of or both a number and types of the modules that execute the data processing in parallel, during execution of a specific data process of executing the data processing by each module at a preset execution timing.
Abstract: A scanner module and an image scanning apparatus employing the same. The scanner module comprises an illuminator for illuminating light on an object to be scanned. The illuminator includes a light emitting diode, a light guide extending in a main scanning direction to change a direction of the light received from the light emitting diode, and at least one elastic member to elastically support at least one longitudinal end of the light guide. As the light guide is elastically supported by the elastic member, convex deformation or bowing of an emission face of the light guide due to thermal expansion can be reduced.
March 30, 2015
Date of Patent:
December 27, 2016
SAMSUNG ELECTRONICS CO., LTD.
Jung Kwon Kim, Dong Hua Lee, Hyun Surk Kim, Kyung Rok Kim
Abstract: An image forming unit forms a toner image on an image carrier, and transfers the toner image to a recording medium. A voltage generation circuit generates a high voltage used for the image forming unit. A control circuit is connected to the voltage generation circuit via a cable, and controls the high voltage generated by the voltage generation circuit. A detection unit detects a current flowing in a load of the image forming unit to which the high voltage generated by the voltage generation circuit is applied. A determination unit determines an error in accordance with a current range in which the current detected by the detection unit falls. The current range is included among a plurality of current ranges that are in one-to-one correspondence with a plurality of errors.
Abstract: A sheet-fed scanner comprising a scan channel, a feeding unit, a transmitting unit, a background sheet, a background light source and a scan module is provided. The feeding unit is disposed at an inlet of the scan channel for feeding a document. The transmitting unit transmits the document to pass through the scan channel. The background sheet is disposed on a side of the scan channel, and has a first surface and a second surface. The first surface faces towards the scan channel. The background light source faces towards the second surface to provide an intermittent light signal to the background sheet, so that the background sheet correspondingly displays an intermittent variation background image on the first surface. The scan module is disposed on another side of the scan channel, and captures a document image of a document and the intermittent variation background image to generate scan data accordingly.