JP2008187244A - Original size detector and image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original size detector that restrains a decrease in productivity because of detection operation and an influence of a cost increase as much as possible while detecting the size of an original not only in a horizontal scanning direction but also in a vertical scanning direction, and achieves an user-friendly man-machine interface, and to provide an image reader. <P>SOLUTION: In the image reader, a lamp is lit for a time width required for determining the vertical scanning size which is required for reading an original. For example, an image reading means is positioned at the maximum size of the original read size before detecting the size, moves to the original read start position from the maximum size position when an open/close detection means changes from opening to closing, reads the original in that interval, and turns on the lamp only from the maximum to the minimum value of the size to be subjected to vertical scanning detection. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a document size detection device and an image reading device, and more particularly to a technique suitably applied to document size detection performed in an image reading unit of an image reading device used in a digital copying machine, a multi-function peripheral, or the like. is there.

  Conventionally, in an original reading apparatus, an infrared sensor is used as a method for detecting an original size when reading a book. However, in recent years, as a part of cost reduction, an infrared sensor is not used but an original is read using a line sensor for reading an original. A method of detecting the size has come to be used. Regarding the document size detection method using a document reading line sensor as the prior art, the following three patent documents are listed.

  First, as for Patent Document 1, the document size detection device of the document is a method of determining the document size in the main scanning direction assuming that the inside of the document is white and the outside of the document is black when the platen is opened. If it comes, the line sensor reading position is moved, and the size is detected by the white line in the document.

  Further, in the document size detection apparatus of Patent Document 2, the method for determining the document size in the main scanning direction on the assumption that the inside of the document is white and the outside of the document is black when the pressure plate is opened is the same as in the conventional technique 1, but the lamp is turned on. It is characterized by taking data under two conditions, when the lamp is off and when the lamp is extinguished, and removing the influence of ambient light.

  In the document size detection apparatus of Patent Document 3, the method for determining the document size in the main scanning direction on the assumption that the inside of the document is white and the outside of the document is black when the pressure plate is opened is the same as in the conventional technique 1, but the main scanning direction. By using the read data of the line sensor at a plurality of points, a plurality of types of document sizes are detected simultaneously.

The three prior arts mentioned above all refer only to document size detection in the main scanning direction, and conventional infrared sensors are used for size detection in the sub-scanning direction. In order to further reduce the cost, it is desirable to respond without using an infrared sensor for size detection in the sub-scanning direction. Therefore, when detecting the document size in the sub-scanning direction using the document reading line sensor, it is necessary to read about the size of the document to be detected (movement of the line sensor). However, if the original reading for size detection (pre-scan) is performed for each original original reading (main scanning), there arises a problem that reading productivity is lowered. For this reason, a method that does not take as much time as possible for the pre-scan is desirable. In addition, since reading is performed with the pressure plate open, it is desirable to realize a user-friendly interface by shortening the lamp-on time as much as possible.
JP-A-10-257255 JP 2000-138798 A JP 2003-198809 A

  Therefore, in order to solve the above-mentioned problems, the entire document scan (pre-scan) is not performed as much as possible (low productivity reduction), and the conventional reading sequence is actively used, or the document size in the main scanning direction as much as possible. Move closer to the detection sequence (small control change), and make the memory size for document size detection as close as possible to the size required for document size detection in the main scanning direction (small cost increase). An object is to simultaneously detect the document size in the sub-scanning direction by shortening the time as much as possible (realization of a man-machine interface).

  In order to solve such a problem, the present invention provides a document irradiating unit, an image reading unit that scans a document by the document irradiating unit and reads image data of the document line by line, and an open / close that detects opening / closing of the document pressing plate. The main scanning size and the sub-scanning size of the document are detected by using the reading image data at an arbitrary position in the main / sub-scanning direction independently of the main / sub-scanning direction from the image data obtained by the detection unit and the image reading unit. An image reading apparatus including a size determination unit that determines a scan size is characterized in that a lamp that is necessary for reading a document is lit for a time width that is necessary for determining a sub-scan size.

  As described above, a user-friendly man-machine interface can be realized by turning on the lamps necessary for document size detection reading for the time width necessary for sub-scanning size determination.

  As another aspect, the position of the image reading unit before the size detection is positioned at the maximum size of the document reading size, and when the open / close detection unit is changed from open to closed, the position of the maximum size is changed. The image reading means may move to the original reading start position, read the original in that section, and at the same time, the lamp may be turned on only from the maximum value to the minimum value of the size to be detected in sub-scanning.

  According to the above aspect, before the size detection, the position of the image reading means is positioned at the maximum size of the original reading size, and when the open / close detection means of the original holding plate is changed from open to closed, the original reading is performed from the position of the maximum size. By moving the image reading means to the start position and reading the document in that section, the overhead time from closing the document pressing plate to reading the document can be reduced, so that the productivity reduction can be suppressed as much as possible. In addition, by setting the position of the image reading unit before the size detection to the maximum size of the original reading size, it is not necessary to switch the control depending on the type of the original size to be detected, and the control common to the models is possible. In addition, a user-friendly man-machine interface can be realized by lighting the lamp for a time width necessary for sub-scan size determination (from the maximum value to the minimum value required for sub-scan detection).

  Further, as another aspect, the position of the image reading unit before performing size detection is positioned at the maximum reading size required from the size to be detected, and when the open / close detection unit changes from open to closed, The image reading means moves from the position of the maximum size necessary for detection to the document reading start position, and at the same time as reading the document in that section, the lamp is turned on only from the start of scanning to the minimum value of the size to be detected. You may do it.

  According to the above aspect, the position of the image reading unit before performing size detection is positioned at the maximum reading size required from the size to be detected, and when the document holding plate opening / closing detection unit is changed from open to closed, the maximum By moving the image reading means from the size position to the document reading start position and reading the document in that section, the overhead time from closing the document pressing plate to reading the document can be reduced, so that productivity reduction is minimized. be able to. In addition, by setting the position of the image reading means before performing size detection to the maximum reading size required from the size to be detected, it is possible to achieve optimal control of that model, further reducing overhead time and reducing productivity. Can be suppressed. In addition, a user-friendly man-machine interface can be realized by lighting the lamp for a time width necessary for sub-scan size determination (from the maximum value to the minimum value required for sub-scan detection).

  As another aspect, the position of the image reading means before the size detection is located at a start position where normal reading is performed, and when the open / close detection means changes from closed to open, the original is read from the start position. When the image reading means moves to the position of the maximum reading size and changes from open to closed, the image reading means moves from the position of the maximum size to the document reading start position, and simultaneously reads the document in that section. The lamp lighting may be turned on only from the maximum value to the minimum value of the size to be detected in sub-scanning.

  According to the above aspect, before the size detection, the position of the image reading unit is positioned at the start position where normal reading is performed, and when the document holding plate open / close detection unit is changed from closed to open, the maximum document reading from the start position is performed. When moving to the size position and changing from open to closed, the image reading means moves from the position of the maximum size to the document reading start position and reads the document in that section, thereby reading the document without size detection. In some cases, there is no need to move the document reading means, no overhead time, and no reduction in productivity. In addition, since the overhead time from when the document pressing plate is closed to when the document is read can be reduced, productivity reduction can be suppressed as much as possible. In addition, by setting the position of the image reading unit before the size detection to the maximum size of the original reading size, it is not necessary to switch the control depending on the type of the original size to be detected, and the control common to the models is possible. In addition, a user-friendly man-machine interface can be realized by lighting the lamp for a time width necessary for sub-scan size determination (from the maximum value to the minimum value required for sub-scan detection).

  As another aspect, the position of the image reading means before the size detection is located at a start position where normal reading is performed, and when the open / close detection means changes from closed to open, the position is detected from the start position. When the image reading means moves to the position of the maximum size necessary for the change and changes from open to closed, the image reading means moves from the position of the maximum size to be detected to the document reading start position, and the document reading in that section is performed. At the same time, the lamp lighting may be turned on only up to the minimum value of the size to be detected from the start of scanning.

  According to the above aspect, before the size detection, the position of the image reading means is located at the start position where normal reading is performed, and when the open / close detection means of the document pressing plate changes from closed to open, the detection is performed from the start position. When moving from the desired size to the position of the required maximum reading size and changing from open to closed, the image reading means moves from the maximum size position to the original reading start position, and reads the original in that section. When reading a document without performing size detection, it is not necessary to move the document reading means, overhead time is not required, and productivity is not reduced. In addition, by setting the position of the image reading means before performing size detection to the maximum reading size required from the size to be detected, it is possible to achieve optimal control of that model, further reducing overhead time and reducing productivity. Can be suppressed. In addition, a user-friendly man-machine interface can be realized by lighting the lamp for a time width necessary for sub-scan size determination (from the maximum value to the minimum value required for sub-scan detection).

  As another aspect, the position of the image reading means before size detection is located at a start position where normal reading is performed, and when the open / close detection means changes from open to closed, the original is read from the start position. The image reading means may move to the position of the maximum reading size, and the original may be read in that section. At the same time, the lamp may be turned on only from the minimum value to the maximum value of the size to be detected in sub-scanning.

  According to the above aspect, before the size detection, the position of the image reading means is located at the start position where normal reading is performed, and when the opening / closing detection means of the document pressing plate is changed from open to closed, the maximum document reading from the start position is performed. By moving the image reading means to the position of the size and reading the original in that section, when reading the original without detecting the size, the original reading means does not need to be moved and no overhead time is required, so that the productivity is not reduced. Further, since the size detection reading control can be made the same as the normal document reading, the control change can be reduced and the development efficiency can be improved. Further, by setting the size detection reading size to the maximum size, it is not necessary to switch the control depending on the type of document size to be detected, and control common to all models is possible. In addition, a user-friendly man-machine interface can be realized by lighting the lamp for a time width necessary for sub-scan size determination (from the maximum value to the minimum value required for sub-scan detection).

  As another aspect, the position of the image reading means before size detection is located at a start position where normal reading is performed, and when the opening / closing detection means changes from open to closed, the position is detected from the start position. The image reading means moves to the position of the maximum size required for reading and reading the document in that section. At the same time, the lamp is turned on only from the minimum value to the maximum value of the size to be detected in the sub-scan. Good.

  According to the above aspect, before the size detection, the position of the image reading unit is located at the start position where normal reading is performed, and when the open / close detection unit of the document pressing plate changes from open to closed, detection is desired from the start position. By moving the image reading means from the size to the position where the required reading is the maximum size and reading the original in that section, when reading the original without size detection, the original reading means does not need to be moved and overhead time is not required Productivity is lost. In addition, by setting the size detection reading size to the required maximum reading size, it is possible to realize optimal control of the model, further reduce the overhead time, and suppress productivity reduction. In addition, a user-friendly man-machine interface can be realized by lighting the lamp for a time width necessary for sub-scan size determination (from the maximum value to the minimum value required for sub-scan detection).

  Another aspect is an image reading apparatus equipped with the document size detection apparatus described above.

  According to the present invention, there are provided a document size detection apparatus and an image reading apparatus that realize a man-machine interface that suppresses the effects of productivity reduction and cost increase as much as possible, and these apparatuses can be used only in the main scanning direction. First, it is possible to detect the document size in the sub-scanning direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image reading apparatus according to an embodiment of the present invention. This image reading apparatus irradiates a document 10 placed on a contact glass 1 forming a document surface with light from a lamp 2 and reflects light reflected by a first mirror 3, a second mirror 4, and a third mirror 5. The light is collected by the lens 8 and imaged on the CCD 9. While the lamp 2 and the first mirror 3 travel a distance L, the second mirror 4 and the third mirror 5 travel a distance L / 2. This keeps the optical path length of the optical system constant and scans the entire document.

  FIG. 2 is a perspective view showing a mechanical configuration of the image reading apparatus of FIG. The first carriage 6 including the lamp 2 and the first mirror 3 is attached to the drive wire 11, and the second carriage 7 including the second mirror 4 and the third mirror 5 is wound around the pulley 12. The drive wire 11 is wound around the wire pulley 15 connected to the drive shaft 14, and the drive of the motor 18 is transmitted by the timing pulley 16 and the timing belt 17. A position where a certain distance is returned after one end of the first carriage 6 crosses the home position sensor 13 is defined as a home position.

  FIG. 3 shows an electrical block diagram in a series of copying operations. When a document is set on the scanner 1001 and the start key is pressed, the scanner 1001 reads the document, performs a series of image processing in the IPU 1002, outputs image data to the printer 1003, and discharges the paper. Necessary parameters in the scanner 1001, the IPU 1002, and the printer 1003 are held in the RAM 1008, and are set for each device by the CPU 1004. Further, mode information necessary for parameter setting is configured so that the user can specify using the operation unit 1005, and the CPU 1006 and the CPU 1004 in the operation unit 1005 communicate to exchange information. Yes.

  FIG. 4 shows a block diagram in the IPU 1002 which is a main component of the present invention. Although desired image processing is performed on the original reading data received from the scanner 1001, when the original size detection operation is performed, the image data is stored in a multi-line memory 1012 connected to the image processing module 1011. A memory control 1013 for controlling the multi-line memory 1012 is also provided, so that the CPU 1004 can read / write the multi-line memory 1012 data.

  FIGS. 5 to 10 are flowcharts showing an original size detection operation sequence according to the present invention, and FIGS. 11 to 16 are block diagrams showing an original size detection operation sequence according to the present invention. Hereinafter, the document size operation will be described with reference to FIGS. 5 to 10 and FIGS.

  5 and 11 show a flowchart and a block diagram for claim 2. In the standby state, the document reading means (hereinafter referred to as a carriage) moves to the document size detection position (step S101). As shown in the upper right diagram of FIG. 11, the document size detection position is located at the end of the maximum document reading size, and then preparations necessary for document size detection are made (step S102). In step S102, setting of document reading timing for document size detection as shown in FIGS. 18 and 19 and preparation setting necessary for shading correction as necessary are executed.

  After that, it is detected that the pressure plate is closed, or when the user starts reading the document, the document size detection operation is started (step S103 / YES). The opening / closing of the pressure plate is detected by ON / OFF of the DF opening / closing sensor. When the document size detection is started, document reading is started as shown in the lower right diagram in FIG. 11 (step S104). After the document reading starts, the lamp is turned on when the carriage reaches the position of the maximum size necessary for size detection (step S105). After the lamp is turned on, the original for size detection is read (step S106), and this time, the lamp is turned off when the carriage reaches the position of the minimum size necessary for size detection (step S107).

  In step S106, a document size write signal is generated, image data is read within the valid period of the write signal, and the process is terminated. At this time, reading is executed while moving the carriage while scanning the document, thereby reading images at different positions on the document and reading image data at a plurality of positions in the sub-scanning direction. After the lamp is turned off, the carriage is moved to the original document reading (main scanning) position (step S108). When the processing in step S107 is completed, the read document image data is extracted to analyze the document size (step S109).

  In the present embodiment, the read document image data is taken out by reading data stored in the multi-line memory 1012 from the CPU 1004 as shown in FIG. The image data extracted in step S109 is analyzed (step S110), and the document size is determined (step S111). If the determination of the document size is successful (step S111 / YES), the document size is determined (step S112). Here, the determination of the document size is specifically to store the document size information in the RAM 1008 which is a program execution memory connected to the CPU 1004 in FIG. The determined document size information is read and used. After the document size is determined, the document size detection operation is completed.

  If determination of the document size fails in step 111, the document size detection operation is completed without determining the document size. Examples of document size determination failures include a black document, the influence of external light on the document table, and the illumination state of the illumination lamp (reading with the lamp turned on but the light quantity is not stable) For example, the size of the document cannot be determined from the read data. The basic sequence of the document size detection operation in the present invention is as described above.

  6 and 12 show a flow chart and a block diagram for claim 3. In the standby state, the carriage moves to the document size detection position (step S201). As shown in the upper right diagram of FIG. 12, the document size detection position is positioned at the maximum value of necessary size detection reading, and thereafter, preparations necessary for document size detection are made (step S202). The maximum size detection reading required will be described with reference to FIGS. In the case of FIG. 11, it is desired to identify three types of document sizes of A3 / A4 width / A4 length. In this case, the presence / absence of a document outside the A4 length may be determined, and even data near the outside of the A4 length may be read. In step S202, setting of document reading timing for document size detection as shown in FIGS. 18 and 19 and preparation settings necessary for shading correction are executed as necessary.

  After that, it is detected that the pressure plate is closed, or when the user starts reading the document, the document size detection operation is started (step S203 / YES). The opening / closing of the pressure plate is detected by ON / OFF of the DF opening / closing sensor. When document size detection is started, document reading is started, and at the same time, the lamp is turned on (step S204). Then, a document for size detection is read (step S205), and the lamp is turned off when the carriage reaches the position of the minimum size necessary for size detection (step S206).

  In step S205, a write signal for a document size is generated, image data is read within the valid period of the write signal, and the process ends. At this time, reading is executed while moving the carriage while scanning the document, thereby reading images at different positions on the document and reading image data at a plurality of positions in the sub-scanning direction. After the lamp is turned off, the carriage is moved to the original document reading (main scanning) position (step S207). When the processing in step S207 is completed, the read document image data is extracted to analyze the document size (step S208).

  In the present embodiment, the read document image data is extracted by reading data stored in the multi-line memory 1012 from the CPU 1004 shown in FIG. Then, the image data extracted in step S208 is analyzed (step S209), and the document size is determined (step S210). If the determination of the document size is successful, the document size is determined (step S210 / YES, step S211). Specifically, the determination of the document size is to store the document size information in the program execution memory RAM 1008 connected to the CPU 1004 in FIG. 4, and thereafter, the document size information determined as necessary. Is read and used. After the document size is determined, the document size detection operation is completed.

  On the other hand, if the determination of the document size fails (step S210 / NO), the document size detection operation is completed without determining the document size. Examples of document size determination failures include a black document, the influence of external light on the document table, and the illumination state of the illumination lamp (reading with the lamp turned on but the light quantity is not stable) For example, the size of the document cannot be determined from the read data. The basic sequence of the document size detection operation in the present invention is as described above.

  7 and 13 show a flowchart and a block diagram for claim 4. In the standby state, the carriage is normally positioned at the original reading start position (home position), and when the pressure plate is opened from the closed state (step S301 / YES), the carriage moves to the original size detection position (step S301). S302). The opening / closing of the pressure plate is detected by ON / OFF of the DF opening / closing sensor. The document size detection position is located at the end of the maximum document reading size, and then preparations necessary for document size detection are made (step S303). In step S303, the setting of the document reading timing for document size detection as shown in FIGS. 18 and 19 and the preparation setting necessary for the shading correction are executed as necessary.

  After that, it is detected that the pressure plate is closed, or the document size detection operation is started when the user starts reading the document (step S304). When document size detection is started, document reading is performed (step S305). After the document reading starts, the lamp is turned on when the carriage reaches the position of the maximum size necessary for size detection (step S306). Then, after the lamp is turned on, a document for size detection is read (step S307), and this time, the lamp is turned off when the carriage reaches the position of the minimum size necessary for size detection (step S308).

  In step S307, a write signal for the document size is generated, image data is read within the valid period of the write signal, and the process ends (step S309). At this time, reading is executed while moving the carriage while scanning the document, thereby reading images at different positions on the document and reading image data at a plurality of positions in the sub-scanning direction. In parallel with the reading, the carriage is moved to the original document reading (main scanning) position. When the processing in step S309 is completed, the read document image data is extracted to analyze the document size (step S310).

  In the present embodiment, the read document image data is extracted by reading data stored in the multi-line memory 1012 from the CPU 1004 shown in FIG. The image data extracted in step S310 is analyzed, and the document size is determined (step S311). If the determination of the document size is successful (step S312 / YES), the document size is determined (step S313). Specifically, the determination of the document size is to store the document size information in the program execution memory RAM 1008 connected to the CPU 1004 in FIG. 4, and thereafter, the document size information determined as necessary. Is read and used. After the document size is determined, the document size detection operation is completed.

  On the other hand, when the determination of the document size fails (step S312 / NO), the document size detection operation is completed without determining the document size. Examples of document size determination failures include a black document, the influence of external light on the document table, and the illumination state of the illumination lamp (reading with the lamp turned on but the light quantity is not stable) For example, the size of the document cannot be determined from the read data. The basic sequence of the document size detection operation in the present invention is as described above.

  8 and 14 show a flowchart and a block diagram for claim 5. In the standby state, the carriage is normally positioned at the original reading start position (home position), and when the pressure plate is opened from the closed state (step S401 / YES), the carriage moves to the original size detection position (step S401). S402). The opening / closing of the pressure plate is detected by ON / OFF of the DF opening / closing sensor. The document size detection position is positioned at the maximum value of necessary size detection reading, and thereafter, preparations necessary for document size detection are made (step S403). The maximum size detection reading required will be described with reference to FIGS. In the case of FIG. 13, it is desired to identify three types of document sizes of A3 / A4 width / A4 length. In this case, the presence / absence of a document outside the A4 length may be determined, and even data near the outside of the A4 length may be read.

  In step S403, setting of document reading timing for document size detection as shown in FIGS. 18 and 19 and preparation setting necessary for shading correction as necessary are executed. After that, it is detected that the pressure plate is closed, or when the user starts reading the document, the document size detection operation is started (step S404). When the document size detection is started, the document reading is started, and at the same time, the lamp is turned on (step S405). Then, a document for size detection is read (step S406), and the lamp is turned off when the carriage reaches the position of the minimum size necessary for size detection (step S407).

  In step S406, a document size write signal is generated, image data is read within the valid period of the write signal, and the process ends (step S408). At this time, reading is executed while moving the carriage while scanning the document, thereby reading images at different positions on the document and reading image data at a plurality of positions in the sub-scanning direction. In parallel with the reading, the carriage is moved to the original document reading (main scanning) position. When the processing in step S408 is completed, the read document image data is extracted to analyze the document size (step S409).

  In the present embodiment, the read document image data is extracted by reading data stored in the multi-line memory 1012 from the CPU 1004 shown in FIG. The image data extracted in step S409 is analyzed, and the document size is determined (step S410). If the determination of the document size is successful (step S411 / YES), the document size is determined (step S412). Specifically, the determination of the document size is to store the document size information in the program execution memory RAM 1008 connected to the CPU 1004 in FIG. 4, and thereafter, the document size information determined as necessary. Is read and used. After the document size is determined, the document size detection operation is completed.

  On the other hand, when the determination of the document size fails (step S411 / NO), the document size detection operation is completed without determining the document size. Examples of document size determination failures include a black document, the influence of external light on the document table, and the illumination state of the illumination lamp (reading with the lamp turned on but the light quantity is not stable) For example, the size of the document cannot be determined from the read data. The basic sequence of the document size detection operation in the present invention is as described above.

  9 and 15 show a flowchart and a block diagram for claim 6. In the standby state, the carriage is normally positioned at the document reading start position (home position), and preparations necessary for document size detection are made (step S501). In step S501, setting of document reading timing for document size detection as shown in FIGS. 18 and 19 and preparation setting necessary for shading correction as necessary are executed.

  Thereafter, the original size detection operation starts when the pressure plate changes from the opened state to the closed state (detection of closing), or when the user starts reading the original (step S502). When document size detection is started, document reading is started (step S503). After the document reading is started, the lamp is turned on when the carriage reaches the position of the minimum size necessary for size detection (step S504). After the lamp is turned on, the document for size detection is read (step S505), and the lamp is turned off when the carriage reaches the position of the maximum size necessary for size detection (step S506).

  In step S505, a write signal for a document size is generated, image data is read within the valid period of the write signal, and the process ends. At this time, reading is executed while moving the carriage while scanning the document, thereby reading images at different positions on the document and reading image data at a plurality of positions in the sub-scanning direction. In parallel with the reading, the carriage is moved to the original document reading (main scanning) position (step S507). For the size detection, the maximum size is read. In the case shown in FIG. 15, reading is performed for the A3 size. When the processing in step S507 is completed, the read document image data is extracted to analyze the document size (step S508).

  In the present embodiment, the read document image data is extracted by reading data stored in the multi-line memory 1012 from the CPU 1004 shown in FIG. The image data taken out in step S508 is analyzed to determine the document size (step S509). When the determination of the document size is successful (step S510 / YES), the document size is determined (step S511). Specifically, the determination of the document size is to store the document size information in the program execution memory RAM 1008 connected to the CPU 1004 in FIG. 4, and thereafter, the document size information determined as necessary. Is read and used. After the document size is determined, the document size detection operation is completed.

  On the other hand, if the determination of the document size fails (step S510 / NO), the document size detection operation is completed without determining the document size. Examples of document size determination failures include a black document, the influence of external light on the document table, and the illumination state of the illumination lamp (reading with the lamp turned on but the light quantity is not stable) For example, the size of the document cannot be determined from the read data. The basic sequence of the document size detection operation in the present invention is as described above.

  10 and 16 show a flowchart and a block diagram for claim 7. In the standby state, the carriage is normally positioned at the document reading start position (home position), and preparations necessary for document size detection are made (step S601). In step S601, setting of document reading timing for document size detection as shown in FIGS. 18 and 19 and preparation setting necessary for shading correction as necessary are executed.

  Thereafter, the original size detection operation is started when the platen is changed from the opened state to the closed state (detection of being closed) or when the user starts reading the original (step S602). When document size detection is started, document reading is started (step S603). After the document reading is started, the lamp is turned on when the carriage reaches the position of the minimum size necessary for size detection (step S604). After the lamp is turned on, a document for size detection is read (step S605), and this time, the lamp is turned off when the carriage reaches the position of the maximum size necessary for size detection (step S606).

  In step S605, a document size write signal is generated, image data is read within the valid period of the write signal, and the process ends. At this time, reading is executed while moving the carriage while scanning the document, thereby reading images at different positions on the document and reading image data at a plurality of positions in the sub-scanning direction. At the same time as reading, the carriage is moved to the original document reading (main scanning) position (step S606). As the read size for size detection, the maximum size necessary for size detection is read. In the case shown in FIG. 16, reading for A4 vertical size is performed. When the processing in step S606 is completed, the read document image data is extracted to analyze the document size (step S607).

  In the present embodiment, the read document image data is extracted by reading data stored in the multi-line memory 1012 from the CPU 1004 shown in FIG. The image data extracted in step S607 is analyzed, and the document size is determined (step S608). If the determination of the document size is successful (step S609 / YES), the document size is determined (step 610). Specifically, the determination of the document size is to store the document size information in the program execution memory RAM 1008 connected to the CPU 1004 in FIG. 4, and thereafter, the document size information determined as necessary. Is read and used. After the document size is determined, the document size detection operation is completed.

  On the other hand, when the determination of the document size fails (step S609 / NO), the document size detection operation is completed without determining the document size. Examples of document size determination failures include a black document, the influence of external light on the document table, and the illumination state of the illumination lamp (reading with the lamp turned on but the light quantity is not stable) For example, the size of the document cannot be determined from the read data. The basic sequence of the document size detection operation in the present invention is as described above.

  FIG. 17 shows an example of the memory control 1013. The line sensor reading is performed by receiving from the image processing module 1011 an XLSYNC signal that is a reference for one line, PCLK that is a pixel clock, and an XFSYNC signal that indicates a line sensor reading start trigger, and a write reset (XWRST) signal and write An enable (XWE) signal is passed. At the same time, the CPU 1004 receives four parameters indicating the memory write area, ie, main scan start, main scan width, sub scan start, and sub scan width, and determines the memory write position from the two reference signals XFSYNC and XLSYNC.

  FIG. 18 shows the timing in the sub-scanning direction, and FIG. 19 shows the timing in the main scanning direction. By having the above configuration as the memory control, data of a plurality of patches in the two-dimensional direction as shown in FIG. 20 can be simultaneously written into the memory (the hatched portion indicates the memory writing area).

  FIG. 21 shows an example of image data extraction in the flowcharts of FIGS. The patch data shown in FIG. 20 is read from the plurality of line memories 1012 one by one to the RAM 1008 of the CPU 1004, and the average value of one patch is obtained and binarized, thereby performing monochrome determination of the patch. This will be described with reference to the flowchart of FIG. First, the monochrome determination flow is started, and the number of pixels in one patch is set (step S701). Thereafter, reading is performed in units of one pixel from the multi-line memory 1012 (step S702), and the set N pixels are added (step S703 / NO, step S704).

  Thereafter, an average value in one patch is obtained (step S705), and the binarization of the patch is performed (step S706). Based on the result, the black and white pixels of the patch are determined (steps S707 and 708), and the monochrome determination flow ends. Note that steps S703 and 705 for performing a total average after N pixel total addition as a flow for calculating an average value, for example, adding only in the main scanning direction to determine an average for one line, and then adding and averaging the next line. The method of repeatedly performing final determination has no effect on the present invention.

  Next, an embodiment of image data analysis in the flowcharts of FIGS. This will be described with reference to the table of FIG. 22 and FIG. 23 showing image data reading positions and document sizes. As the reading patch, SEN11, SEN12, SEN21, and SEN22 are used as shown in FIG. Further, it is assumed that the document size detected as an example is A3, A4 horizontal, A4 vertical, and other. First, white / black of each read patch is determined by the processing shown in FIG. Then, the original size is determined from the table of FIG. 22 based on the determined white / black.

  If SEN1-1, SEN12, SEN21, and SEN22 are all white, it is determined that there are documents at all four reading positions, and the document is determined to be A3 size. If SEN11 and SEN-12 are white and SEN21 and SEN22 are black, it is determined that there is no original on the rear side in the sub-scanning direction, and the original is determined to be A4 horizontal. If SEN11 and SEN21 are white and SE-N12 and SEN22 are black, it is determined that there is no original on the back side in the main scanning direction, and it is determined that the original is A4 vertical. If SEN11, SEN12, SEN21, and SEN2-2 are all black, it is determined that there are no documents at all four reading positions, and it is determined that the size is smaller than A4 or there is no document. If none of the above four patterns is applicable, it is determined that a detection error has occurred somewhere, and the document size is not detected.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

1 is a cross-sectional view illustrating a schematic configuration of an image reading apparatus according to an embodiment of the present invention. 1 is a perspective view illustrating a mechanical configuration of an image reading apparatus according to an embodiment of the present invention. 1 is a block diagram illustrating a functional configuration of an image reading apparatus according to an embodiment of the present invention. 1 is a block diagram illustrating a functional configuration of an image reading apparatus according to an embodiment of the present invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. It is a figure for demonstrating the document size detection in embodiment of this invention. It is a figure for demonstrating the document size detection in embodiment of this invention. It is a figure for demonstrating the document size detection in embodiment of this invention. It is a figure for demonstrating the document size detection in embodiment of this invention. It is a figure for demonstrating the document size detection in embodiment of this invention. It is a figure for demonstrating the document size detection in embodiment of this invention. 1 is a block diagram illustrating a functional configuration of an image reading apparatus according to an embodiment of the present invention. It is a timing chart of the subscanning direction of the line sensor reading reference signal in the embodiment of the present invention. It is a timing chart of the main scanning direction of the line sensor reading reference signal in the embodiment of the present invention. It is a figure for demonstrating the document size detection in embodiment of this invention. 5 is a flowchart showing a flow of a document size detection operation in the embodiment of the present invention. It is a figure for demonstrating the document size detection in embodiment of this invention. It is a figure for demonstrating the document size detection in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Contact glass 2 Lamp 3 1st mirror 4 2nd mirror 5 3rd mirror 6 1st carriage 7 2nd carriage 8 Lens 9 CCD
DESCRIPTION OF SYMBOLS 10 Document 11 Drive wire 12 Pulley 13 Home position sensor 14 Drive shaft 15 Wire pulley 16 Timing pulley 17 Timing belt 18 Motor 1001 Scanner 1002 IPU
1003 Printer 1004, 1006 CPU
1005 Operation unit 1007 Display unit 1008 RAM
1011 Image processing module 1012 Multiple line memory 1013 Memory control

Claims (8)

Obtained by the original irradiating means, the image reading means for scanning the original by the original irradiating means and reading the image data of the original for each line, the open / close detecting means for detecting the opening / closing of the original pressing plate, and the image reading means. Size determining means for determining the main scanning size and the sub-scanning size of the document using the read image data at an arbitrary position in the main / sub-scanning direction independently of the main / sub-scanning direction from the image data of a plurality of lines. In the image reading device,
A document size detecting apparatus characterized in that a lamp necessary for reading a document is lit for a time width necessary for sub-scanning size determination.   The position of the image reading unit before performing size detection is positioned at the maximum size of the document reading size, and when the open / close detection unit is changed from open to closed, the image is read from the maximum size position to the document reading start position. 2. The document size detection according to claim 1, wherein the reading unit moves and reads the document in the section, and at the same time, the lamp is turned on only from the maximum value to the minimum value of the size to be detected in sub-scanning. apparatus.   The position of the image reading means before the size detection is positioned at the maximum reading size required from the size to be detected, and when the open / close detection means changes from open to closed, the position of the maximum size required for the detection is The image reading means moves from a position to a document reading start position and reads a document in that section, and at the same time, the lamp is turned on only from the start of scanning to the minimum size to be detected. The document size detection apparatus according to 1.   The position of the image reading unit before performing size detection is located at a start position where normal reading is performed, and when the open / close detection unit changes from closed to open, the position from the start position to the maximum document reading size position is determined. When the image reading means moves and changes from open to closed, the image reading means moves from the position of the maximum size to the original reading start position, and at the same time the original is read in that section, the lamp lighting is 2. The document size detection apparatus according to claim 1, wherein the document size detection apparatus is turned on only from a maximum value to a minimum value of a size to be scanned.   The position of the image reading means before performing size detection is located at the start position where normal reading is performed, and when the open / close detection means changes from closed to open, the position of the maximum size necessary for detection from the start position When the image reading means is moved and changed from open to closed, the image reading means is moved from the position of the maximum size desired to be detected to the original reading start position, and simultaneously reading the original in the section, the lamp 2. The document size detection apparatus according to claim 1, wherein lighting is turned on only from a scan start to a minimum value of a size to be detected.   The position of the image reading means before performing size detection is located at a start position where normal reading is performed, and when the open / close detection means changes from open to closed, the position from the start position to the position of the maximum document reading size is determined. 2. The document size according to claim 1, wherein the image reading means moves and reads the document in the section, and at the same time, the lamp is turned on only from the minimum value to the maximum value of the size to be detected in sub-scanning. Detection device.   The position of the image reading means before performing size detection is located at the start position where normal reading is performed, and when the open / close detection means changes from open to closed, the position of the maximum size necessary for detection from the start position 2. The document size according to claim 1, wherein the image reading means moves to read the document in that section and at the same time, the lamp is turned on only from the minimum value to the maximum value of the size to be detected in sub-scanning. Detection device.   An image reading apparatus equipped with the document size detection apparatus according to claim 1.

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