Abstract: An auto document feeder which loads and feeds a document to a read position provided on a read surface of a reader, the auto document feeder including a conveying device having an upstream roller placed upstream of the read position and a downstream roller placed downstream of the read position, the conveying device conveying the loaded document through the read position, a stabilizing roller provided upstream of the read position and opposing to the read surface, the stabilizing roller stabilizing movement of the document conveyed by the conveying device, and a guide member provided downstream of the read position and opposing to the read surface, the guide member guiding the document conveyed by the conveying device, wherein the following relationship is established the thickness of the document<a gap between the read surface and the stabilizing roller<a gap between the read surface and the guide member.

Abstract: The invention has an object to provide an image forming apparatus in which size information of a document image is used, and various printings can be performed on a sheet in manual feed copy without mistake.

Abstract: A sheet size detecting apparatus having a first arm moved by a moving sheet contacting therewith, a second arm moved by the moving sheet contacting therewith, the second arm being disposed at a location differing from that of the first arm in a direction orthogonal to the movement direction of the sheet, and a sensor, wherein the output level of the sensor when only one of the first arm and the second arm has been moved is the same as the output level thereof when neither of the first arm and the second arm is moved, and the output level of the sensor when both of the first arm and the second arm have been moved differs from the output level thereof when neither of the first arm and the second arm is not moved. Thereby, the cost can be suppressed and yet, the wrong detection of the sheet size can be prevented.

Abstract: A printing method and apparatus includes fingerprinting a sheet of printable media such as paper to obtain a fingerprint. The fingerprint is encrypted using an encryption key known only to the user wanting to print the document. The encrypted fingerprint is then encoded and transferred to the document as machine readable information.

Abstract: A document original size detecting device has a plurality of sensors each including a light emitting portion and a light receiving portion and respectively disposed as corresponding to different sizes of document originals to be placed on a transparent document platen and a detecting section which determines a document original size based on outputs of the sensors. The light emitting portion of each of the sensors emits light to illuminate at least two positions on a document placing region of the document platen on which a document original to be subjected to size detection is placed, and the detecting section determines the document original size based on whether or not the light receiving portion of each of the sensors detects the document original blocking the light in at least one of the two positions.

Abstract: In an embodiment of the present invention, a pickup roller R1 makes soft contact to an upper surface of a manuscript by being lowered incrementally in four raising-lowering operations S1 to S4 in which, when an electromagnetic clutch connects, the pickup roller is lowered, while being rotated, to approach the upper surface of the top manuscript and, when the electromagnetic clutch disconnects, the pickup roller, while stopping to rotate, is raised away from the upper surface of the top manuscript by an amount smaller than a lowering amount. Between an electromagnetic clutch-side engaging portion and a pickup roller-side engaging portion of a torque limiter, an elastic member is arranged that suppresses drive power load fluctuation produced by disconnection/connection of the electromagnetic clutch and applies a biasing force in a direction to raise the pickup roller when the electromagnetic clutch disconnects.

Abstract: A print apparatus comprises a memory for storing compressed print information of at least two or more pages transmitted from a host computer, and executes image formation by extracting the compressed print information read from the memory. When nonconformity between an image size of the page to which the print apparatus is executing the image formation and a paper size fed for the relevant page is detected, the compressed print information, for the page in execution of the image formation, subsequent to the read address on the memory at a point of time of the nonconformity detection is read from the memory, and then extracted and abandoned. Thus, the read address on the memory indicates the head of a page subsequent to the page in execution of the image formation.

Abstract: There is described an image forming apparatus comprising a tray that outputs information by which various kinds of fixed form sized of recording mediums can be discriminated and a controller to acquire a approximate size of a recording medium having an unfixed form size by conducting an operation for detecting a fixed form size of the recording medium by referring to the information if the recording medium having the unfixed form size is stacked on the tray, wherein, according to the approximate size, the controller controls an operation for displaying information corresponding to unfixed form size or sizes registered in advance.

Abstract: There are provided an original table for an original, a linear image sensor for converting light into an electric signal, a first optical system for forming an optical image on a main scanning line onto the linear image sensor, a sub scanning unit for scanning the main scanning line in parallel with a sub scanning direction, and a second optical system forming an optical path that reaches the linear image sensor from a detecting position on the plate surface, which is remote from the main scanning line in a sub scanning direction. A size and an orientation of an original are decided based on an electric signal converted from light that reaches the linear image sensor from the main scanning line via the first optical system, and an electric signal converted from light that reaches the linear image sensor from the detecting position via the second optical system.

Abstract: An image formation device having computer readable instructions that alleviate the necessity of the user to enter the correct page size into the image formation device. The computer readable instructions contain, among other things, a look-up table, or map, of known print media dimensions the image formation device is able to handle. The size of the media loaded into the image formation device is detected and assigned a value according to the look-up table, or map, of the computer readable instructions. The value is compared to the known types of media that are supportable by the printer. These types of media are grouped into predetermined categories according to their respective width dimensions. A determination of whether the image formation device performs a function is made based on the comparison of the converted value to the predetermined group of media.

Abstract: A sheet feed device of this invention includes a sheet feed tray, a sheet feed unit which feeds a sheet placed on the sheet feed tray, a detection sensor which detects the presence/absence of a sheet on the sheet feed tray, and a sensor mounting member which mounts the detection sensor on the sheet feed tray. The sensor mounting member can mount the detection sensor on the sheet feed tray such that the angle of the sensor can be adjusted with respect to the tray.

Abstract: An image forming apparatus includes an automatic document conveying apparatus including a table, first and second conveyance paths, a scanning device, and first and second switchback mechanisms. A document of the document bundle set on the table is reversed and conveyed by the first conveyance path through the scanning device with its first surface facing the scanning device, guided to the first switchback mechanism by the second conveyance path, switched back by the first switchback mechanism, reversed and conveyed to the second switchback mechanism by the second conveyance path, and switched back by the second switchback mechanism to detect a size of the document based on information sent from a sensor included in the first conveyance path. Thereafter, the document is reversed and conveyed by the first conveyance path to the scanning device to have its first surface scanned. A method of automatically conveying documents is also described.

Abstract: An automatic document feeder which is capable of preventing the occurrence of jams that would be caused when a bundle of originals in which originals having lengths in a conveying direction equal to or greater than a predetermined reference length and originals having lengths shorter than the reference length are mixed are conveyed in a high-speed double-sided mode. When the originals are sequentially conveyed, a length of a respective original is detected. If the detected length of a preceding original being conveyed in the high-speed double-sided mode is equal to or greater than a predetermined length, the high-speed double-sided mode in which conveyance of the next original is started after start of non-reading conveyance of the preceding original is switched over to a normal double-sided mode in which the conveyance of the next original is started in advance of the non-reading conveyance of the preceding original.

Abstract: A document size detecting device including a flatbed, a sensing region, a matrix optical sensing unit and a logic processing unit is provided. The flatbed has a first flatbed edge and a second flatbed edge. A first edge and a second edge of the document are respectively aligned with the first flatbed edge and the second flatbed edge. Part of the sensing region is covered by part of the document. The sensing region is formed on the flatbed according to a sensing ability of the matrix optical sensing unit. The matrix optical sensing unit fetches an image from the sensing region and then outputs an image signal accordingly. The logic processing unit receives the image signal and determines the size of the document according to the image signal.

Abstract: An auto document feeder which loads and feeds a document to a read position provided on a read surface of a reader, the auto document feeder including a conveying device having an upstream roller placed upstream of the read position and a downstream roller placed downstream of the read position, the conveying device conveying the loaded document through the read position, a stabilizing roller provided upstream of the read position and opposing to the read surface, the stabilizing roller stabilizing movement of the document conveyed by the conveying device, and a guide member provided downstream of the read position and opposing to the read surface, the guide member guiding the document conveyed by the conveying device, wherein the following relationship is established the thickness of the document<a gap between the read surface and the stabilizing roller<a gap between the read surface and the guide member.

Abstract: A document size sensor is disposed on a document feed path at a location between a document tray and a juncture and on the front side in the primary scanning direction perpendicular to a document feed direction. The document size sensor is located between a sheet edge position for B4-size document sheet and a sheet edge position for A 4 -size document sheet, which are situated on the front side in the primary scanning direction. The document size sensor detects A3 - and B 4 -size document sheets but does not detect A 4 - or B5-size document sheet. Based on a detection signal from the document size sensor, judgment is made as to whether a document sheet fed from the document tray is a larger-sized document sheet or a smaller-sized document sheet.

Abstract: A document inverting-and-transporting apparatus includes a transport path, an inversion-and-transport path, a document transporting unit, a closed portion, a document length detecting unit, a comparing unit, a controlling unit. The transport path includes a first route along which the document is transported from a feeding start position to a transport direction changing position; a joining position; and a reading position. The inversion-and-transport path includes a second route along which the document is transported from the transport direction changing position to the reading position via the joining position. The closed portion constitutes a part of the inversion-and-transport path. The comparing unit compares a detected length of the document with a predetermined length larger than a length of the closed portion. The controlling unit determines whether the document is to be transported to the inversion-and-transport path, based on a result of the comparison.

Abstract: An image forming and reading apparatus includes an image forming portion for forming an image on a fed recording sheet and an image reading portion for reading the image of a fed document. At least a portion of the feeding path of the recording sheet is common to at least a portion of the feeding path of the document, and the image reading portion can be set to a first position moved from the common feeding path and to a second position at which the image of the document that is fed through the common feeding path is read, and a reading position at which the image is read by the image reading portion is located downstream of the image forming portion in a recording sheet feeding direction.

Abstract: An image forming apparatus has a job information acquiring unit for acquiring job information which includes job-related sheet size information, a confirmation-output size determining unit for determining the size of a sheet for confirmation output according to the job information, a job information position designating unit for specifying a portion of the job image information to be printed out on a confirmation-output sheet of a size which is determined by the confirmation-output size determining unit, an editing unit for editing the portion of job image information specified by the job information position designating unit as confirmation-output image information on the confirmation-output sheet of a size determined by the confirmation-output size determining unit, and an image forming unit for carrying out image forming of confirmation-output image information edited by the editing unit on the confirmation-output sheet.

Abstract: The ADF 11 is a device for feeding an original document toward an original document scanning position R, comprising an original document loading unit 31, paper feeding roller 51, pressure sensor 33 and lift plate drive unit 35. The original document loading unit 31 comprises a lift plate 41 allowing an original document to be loaded and vertically movable in an original document loading direction. The paper feeding roller 51 is disposed above the lift plate 41 disposed at the lowermost position with an interval therebetween, and is capable of moving upwardly in coordination with a force received from below from the lift plate 41. The pressure sensor 33 is capable of detecting upward pressure on the paper feeding roller 51. The lift plate drive unit 35 causes the lift plate 41 to be lowered upon detection of upward pressure on the paper feeding roller 51.

Abstract: When a user enters control information for controlling a printing device, the information is stored in a user information storage unit. All combinations of items of the control information capable of being set by the user and values of items incapable of being set by the user, these having been selected so as to be the optimum values for the combinations, are stored as preset values in a combined information storage unit. An information storage unit compares a value in the user information storage unit with a value in the combined information storage unit. If a combination for which agreement is achieved is found in the combined information storage unit, this value is stored in a printing information storage unit and transmitted to the printing device. Thus, an optimum value can be selected and sent to the printing device even with regard to an item incapable of being selected by the user.

Abstract: An original document reading apparatus includes a plurality of point light source elements (e.g. a LED array) in a main scanning direction beneath an original document table, a moving device that moves the point light source elements in a sub scanning direction, and a photo acceptance unit that accepts light reflected from the original document and determines a size of the original document based upon a reaction of a pixel to the light. The plurality of point light source elements are divided into a plurality of blocks to be turned on and off in successive turns per a block starting from a block corresponding to an original document minimum size to a block corresponding to an original document maximum size.

Abstract: An automatic document transportation device includes a document tray, a document discharge tray, a transportation path, a document feed roller, a separating pad, transportation rollers, a Charge Coupled Device (CCD) scanning unit, a Contact Image Sensor (CIS) scanning unit and document discharge rollers. The document tray and the document discharge tray are provided vertically in two stages. The transportation path is formed in the sideways letter-U shape from the document tray to the document discharge tray. The document feed roller and the separating pad are provided in proximity to an inlet of the transportation path, and separate original documents by nipping the original documents in a thickness direction. The transportation rollers nip and transport the original document. The CCD scanning unit is provided directly downstream of a U-turn part of the transportation path and scans a first side of the transported original document.

Abstract: A paper-width detecting device includes a paper guide, a conductive element, a circuit board and a control-processing unit. The paper guide is movably disposed on a paper tray for accommodating different sizes of papers. The conductive element attaching to the paper guide and moving simultaneously with the paper guide has a plurality of first conductive portions. The circuit board has a plurality of conductive wires, which is formed by a plurality of separated second conductive portions on the surface of the circuit board. An insulating region is formed between any two adjacent second conductive portions of each conductive wire. The control-processing unit is for providing an electric voltage between the conductive wires and the conductive element. When the paper guide presses against the paper, the control-processing unit generate a paper-width value corresponding to the number of current passages formed between the first conductive portions and the corresponding conductive wire thereof.

Abstract: There is disclosed an image reading process has determining an estimated size of an original based on a width of the original, securing a memory region, the memory region having capacity to hold a maximum image data associated with the estimated size, generating an image data as the original is conveying over the read window, loading the image data into the memory region, after the original passed the read window determining a page size based on the width and the image data.

Abstract: An imaging device, such as a printer, scanner, copier, multifunctional printer, and the like includes a sensor to detect the size of media fed into the imaging device. The detected media size can be set as the default media size for further operations, if desired.

Abstract: An original comprises a first page and a second page as disposed face-down on the platen surface of an image-processing device. The platen is scanned to form a platen image. The positions of two diagonally-opposite corners of the original are determined based on a fixed platen reference point. An original image is formed by cropping the platen image based on the positions of the two original corners. The size and position of either one selected page or both pages are determined based on the two original corner positions. When the image of only one selected page is desired, the image of the selected page is formed by cropping the original image based on the size and position of the selected page. When the images of both pages are desired, the images of both pages are formed by cropping the original image based on the sizes and positions of both pages.

Abstract: A image-forming apparatus has a light projection unit for projecting light onto a document. A reflection plate having a predetermined pattern corresponding to a size of the document reflects the light projected onto the document. The light reception unit receives the reflected light and forms an image. A control unit determines the size of the document based on the width of the document according to the pattern appearing on the image. When photocopying documents of several sizes using an automatic document feeder, documents are sorted based the document sizes and therefore, the documents can be read out at once without requiring re-setting of the image forming apparatus for different document sizes.

Abstract: An Flat Bed-Multi Function Device includes an MPU, a reading section, a recording section, an operation section, an image memory, and a ratio changing section. In a reduction copy mode, the reading section reads an extended reading area of a document larger than a recording area of recording paper to generate image data. The ratio changing section reduces the image data at a predetermined reduction ratio. The recording section forms an image on a sheet of recording paper on the basis of the reduced image data.

Abstract: In an image forming apparatus having a document feeder for taking up a document from a document bundle placed on a document tray, a controller has a normal mode to perform a normal-size conveyance control by taking up each document from a bundle of documents having the same size, a multi-size mode to perform a multi-size conveyance control by taking up each document from a bundle of documents having various sizes. When the normal mode is carried out, the controller controls to stop the document after the first preset time passes after the trailing edge of the document has been detected, and when multi-size mode is carried out, the controller controls in place of using the first preset time by the second preset time which is set to be a longer time than the first preset time.

Abstract: A sheet supplying apparatus includes a sheet feeding stacker for storing the sheet; a sheet discharging stacker arranged in parallel to the sheet feeding stacker in a vertical direction for storing the sheet; a U-shape conveying path disposed between the sheet feeding stacker to the sheet discharging stacker for guiding the sheet from the sheet feeding stacker to the sheet discharging stacker; a processing platen disposed in the conveying path for processing the sheet; a separating device for separating the sheet on the sheet feeding stacker; a register device for temporarily stopping the sheet and conveying the sheet; a sheet feeding device for conveying the sheet; and a sheet conveying device for conveying the sheet. A sheet discharging device discharges the sheet to the sheet discharging stacker, and an idle roller is disposed in the U-shape conveying path for contacting the sheet to rotate.

Abstract: An image reading apparatus includes a transport path for transporting an original from an original tray to a reading position; a reading device for reading the original at a reading position; a determining device for determining whether the original includes a black and white image or color image; a circulating path for returning the original to the reading position without turning over the original; a discharge path for guiding the original from the reading position to a discharge tray; and selection means for selecting one of the circulating path and the discharge path. The image reading apparatus reads the same side of the original fed from the circulating path again according to a result of the determining device.

Abstract: An image reading apparatus includes a transport path for guiding an original from an original tray to a reading position; a transport device for transporting the original toward a downstream side in a forward direction or toward an upstream side in a reverse direction; a reading device for reading the original at the reading position; a determining device for determining whether the original has a black and white image or color image; and a retreat path disposed at an upstream side of the reading position for retreating at least a part of the original from the transport path. After the determining device determines the original, the original is transported in the reverse direction to retreat it to the retreat path. Then, the original is transported to the reading position, so that the reading device reads the original in a reading mode according to a result of the determination.

Abstract: An enhanced graphical icon system depicting the proper document/paper placement and orientation on the glass or in the auto document feeder for a mopier/copier control panel. The enhanced graphical icon system includes a visual feedback control panel display and an orientation indicator. An original document is accurately described through utilization of original settings button by the automatic detection or manual selection of the appropriate document size, number of sides, page type and page orientation that correspond to the original document. Once the document size is determined, orientation indicator displays to a user the proper location for placing the document, either on the glass or in the ADF, so as to make an accurate copy.

Abstract: An image reading apparatus includes: a detecting section for detecting a size of an original sheet; an image reading section for reading an image described in the original sheet; and a storage medium for storing the read image which is read by the image reading section; wherein before the size of the original sheet is detected by the detecting section, the image reading section reads the image to store the read image in the storage medium; and after the size of the original sheet is detected by the detecting section, a size of the stored image which is stored in the storage medium is changed in accordance with the detected size of the original sheet, which is detected by the detecting section.

Abstract: At least two (groups of) sensors forming an insertion detection sensor are offset from each other in the conveyance direction of a photosensitive material. An insertion speed, which is different for each manual insertion event, is obtained based on the time difference when sensors that have been offset from each other detect the leading end of the photosensitive material. The length of the photosensitive material in the conveyance direction thereof is accurately computed based on the insertion speed and other information. By correcting the errors due to the changeable insertion state of the photosensitive material caused by manual insertion by the operator, the process area of the photosensitive material, required for calculating the amount of replenisher to be replenished, is accurately obtained. Therefore, the amount of the replenisher is appropriately determined and the process capacity of the developer or the fixing solution can constantly be maintained at the satisfactory level.

Abstract: An image reading apparatus includes: a detecting section for detecting a size of an original sheet; an image reading section for reading an image described in the original sheet; and a storage medium for storing the read image which is read by the image reading section; wherein before the size of the original sheet is detected by the detecting section, the image reading section reads the image to store the read image in the storage medium; and after the size of the original sheet is detected by the detecting section, a size of the stored image which is stored in the storage medium is changed in accordance with the detected size of the original sheet, which is detected by the detecting section.

Abstract: The image forming apparatus includes an original document size detector device for detecting a size of an original document to be processed and a non-standard size input instruction screen for inputting a size of an original document to be processed. Normally, the detector device detects the size of an original document, and the original document image data is processed based on the obtained original document size to reproduce an image on the recording material. The non-standard size input instruction screen includes an X key and a Y key that enable the operator to input a new original document size by inputting a difference between the actual document size and reference values, where the reference values are provided based on the original document size obtained by the detector device.

Abstract: An automatic document feeding device is capable of one-side process and double-side process, and includes a paper supply stacker, a paper supply path for transferring a document fed from the paper supply stacker to a sheet processing section, a switchback path for switching back the document processed at the sheet processing section, a paper ejection path for ejecting the document switched back in the switchback path in a reversed condition, and a paper ejection stacker for receiving the document ejected from the paper ejection path. In the double-side process, in accordance with a sheet size of the document to be processed, the device is controlled to switch between a mode wherein only one document is transferred in and ejected from the switchback path and another mode wherein a second document is transferred into the switchback path in the condition that a first document is still in the switchback path.

Abstract: Reproduction systems and methods of operating reproduction devices are described. In one embodiment, a reproduction method comprises receiving multiple pages into a reproduction device for reproduction and positioning the multiple pages within an area in the reproduction device so that they can be reproduced. The multiple pages are scanned using a single scanning cycle, and a single reproduced page is output for each of the multiple pages that was scanned. In another embodiment, a copier comprises one or more processors, an image engine having a scan glass for receiving document pages and being configured to scan document pages and produce copies of the pages. A page feeding manager is associated with the one or more processors and is configured to cause pages to be fed into the copier and processed by the image engine.

Abstract: The image forming apparatus includes an original document size detector device for detecting a size of an original document to be processed and a non-standard size input instruction screen 34 for inputting a size of an original document to be processed. Normally, the original document size detector device detects a size of an original document, and original document image data is processed based on the obtained original document size information to reproduce an image on paper of a corresponding size. The non-standard size input instruction screen 34 is provided with a an X key 46 and a Y key 47 that enable the operator to, when inputting thee size of the original document, select and input new original document size information using an incremental key 44 or a decremental key 45 after reference values are provided based on original document size information obtained by the original document size detector device.

Abstract: A document feeding apparatus includes a paper feeding tray, on which a document is placed, a transfer unit that transfers the document placed on the paper feeding tray to a platen glass, a paper delivery tray for receiving the document transferred to the platen glass, and a platen cover for the platen glass. A first paper delivery port is provided for delivering to a short size tray a document whose length in the transfer direction of the document is shorter than a predetermined value, and a second paper delivery port is provided for delivering to said paper delivery tray a document whose length in the transfer direction of the document is longer than the predetermined value. In addition, an image input portion, the second paper delivery port, and the first paper delivery port are arranged in order with a space therebetween in the transfer direction of the document.

Abstract: An automatic document feeding device is capable of one-side process and double-side process, and includes a paper supply stacker, a paper supply path for transferring a document fed from the paper supply stacker to a sheet processing section, a switchback path for switching back the document processed at the sheet processing section, a paper ejection path for ejecting the document switched back in the switchback path in a reversed condition, and a paper ejection stacker for receiving the document ejected from the paper ejection path. In the double-side process, in accordance with a sheet size of the document to be processed, the device is controlled to switch between a mode wherein only one document is transferred in and ejected from the switchback path and another mode wherein a second document is transferred into the switchback path in the condition that a first document is still in the switchback path.

Abstract: A method in an imaging system for automatically selecting a copy substrate from multiple substrate trays and for improving the productivity and imaging of the copy substrates. The method includes comparison of the dimensions of the copy substrate to the dimensions of the input document in order to automatically select a copy substrate, automatically rotate digital information in order to align the orientation of input and copy documents, center imaging information onto the copy substrate, and to perform various AutoFit functions.

Abstract: In the case where since there is no recording paper in an upper stage cassette in which recording papers of an optimum size (for example, A4 size) should be enclosed, a lower stage cassette in which recording papers of another size are enclosed is used as a temporary paper feeding unit and a paper feed is performed, whether there is a status change such as supply of recording papers, removal of output papers from a paper ejecting unit, or the like or not is discriminated on the basis of a status change signal, whether the recording papers of the A4 size have been supplied to the upper stage cassette or not is discriminated, and whether an automatic paper feeding mode has been set or not is discriminated. Thus, when the recording papers of the A4 size are supplied to the upper stage cassette and the automatic paper feeding mode has been set, the paper feeding unit is switched from the lower stage cassette to the upper stage cassette.

Abstract: An image forming apparatus is provided with an automatic document feeder 20 having an original tray 2101, image reading sections 11 and 12 and a printer section P. The apparatus is provided with an insertion sheet detector for discriminating, when a composite original sheet group obtained by inserting between arbitrary pages of a first original sheet group comprised of original sheets of an identical size an insertion sheet of a size identical to that of the original sheets is set on the original tray 2101, whether the sheet fed to the image reading position is the original sheet of the first original sheet group or the insertion sheet. Through the process of forming the print group corresponding to the above composite original sheet group, the image of a second original prepared separately from the composite original sheet group is formed instead of the image of the insertion sheet.

Abstract: An automatic document conveyance apparatus includes: a document feeding section on which a plurality of documents can be placed, for feeding documents one by one therefrom; a zigzag reversal path through which the document fed from the document feeding section is reversed with respect to front and back sides of each of the documents; a reading position forming device for forming an image reading position of the document fed zigzag from and conveyed to the zigzag reversal path; and a document ejection tray on which the document passed through the reading position forming device and ejected through an ejection path is placed.

Abstract: A method and a device are provided for determining a scanning dimension of a scanned body. The device includes a light source, a detecting unit, and a signal processing unit. The method includes steps of (a) providing an initial optical signal, (b) receiving the initial optical signal and generating an initial detecting signal in response to the initial optical signal, (c) receiving the initial optical signal and generating a complex detecting signal according to the scanning dimension of the scanned body, and (d) determining the scanning dimension of the scanned body by calculating the initial detecting signal and the complex detecting signal.

Abstract: An image forming apparatus includes: a tray on which documents are stacked; a first document size detector for detecting a size of the documents stacked on the tray; a second document size detector for detecting a size of each of the documents conveyed from the tray; an automatic document feeding device having a document reading section for reading an image of each of the documents; an image forming section including a transfer material feeder for feeding transfer materials; and a controller for selecting and feeding transfer materials according to the detected document size.

Abstract: An inverting document feeder feeds a document from the document tray to the position where the image reader reads the document, turns the document over, and then reads the second side. Document size determination sensors detects the document passing through, and determines the size of the document from detections signals of the width of the document and the time elapsed between the detection of the top end of the document and the detection of the bottom end of the document. When the top end of the document reaches the document reading position, image reading is started by a scanner, regardless of whether the document size has been determined or not. The image data thus obtained are written into and read out of a memory unit in a specified order.