JP2010118819A - Image reader, image reading method, image reading program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an image reader for reading an original with high quality, at high speed and at low cost by an original fixed reading method; an image reading method; an image reading program; and a recording medium. <P>SOLUTION: The image reader 1 moves a carriage at a speed corresponding to half resolution of designated resolution in a forward direction from an original front edge side to an end edge side and a backward direction from the original end edge side to the front edge side in a sub-scanning direction to perform original forward reading and backward reading, shifts the forward reading and the backward reading to the sub-scanning direction for one pixel of the designated resolution to execute a two-way image reading operation, and alternately combines forward image data obtained by the forward reading with backward image data obtained by the backward reading in each line to be image data of the original. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, an image reading method, an image reading program, and a recording medium, and more specifically, an image reading apparatus, an image reading method, and an image reading apparatus that read a document with high quality, high speed, and low cost by a fixed document reading method. The present invention relates to a reading program and a recording medium.

  In an image reading apparatus such as a scanner device, a facsimile machine, a copying machine, or a composite device, as an original reading method, an image of the original is read by moving a reading unit with respect to the original fixed on the contact glass. There are a fixed document type reading method (book type reading method) and a document moving type reading method in which a document to be conveyed and moved is read by a fixed reading unit.

  This image reading apparatus of the original fixed type reading system includes an optical scanning unit mounted on a carriage that moves in the sub-scanning direction, and reading light is read from an optical scanning unit mounted on the carriage onto an original fixed on a contact glass. Is irradiated in the main scanning direction. The image reading apparatus reflects the reflected light from the original to the lens of the photoelectric conversion unit by a mirror mounted on the carriage, condenses the light on a CCD (Charge Coupled Device) by the lens, and performs photoelectric conversion by the CCD. Main scanning reading processing for outputting analog image signals for lines is performed. This document reading type image reading apparatus performs main scanning reading for each line and moves the carriage on which the optical scanning unit is mounted in the sub-scanning direction with respect to the home position as a reference. Scanning is sequentially performed to read one page of image data. When the image reading apparatus reads one page of image data, it returns the carriage from the trailing edge of the document to the home position (return operation), and reads the next document until the return operation is completed. I can't.

  In reading an original, it is necessary to move the carriage at a constant speed in the image reading area of the original. However, in the blank area from the leading edge of the original to the image reading area, the carriage is moved at the constant speed. To speed up. After that, in the blank area on the trailing edge side of the document after the image reading area, the carriage is decelerated, moved to the reverse position after passing through the trailing edge of the document, the carriage is stopped, and then the carriage is reversed and the trailing edge of the document and the document A return operation is performed to pass the tip and return to the home position. Therefore, conventionally, in order to perform the scanning process at a high speed, the deceleration speed during the forward path in the blank area on the trailing edge side of the document after the image reading area is changed to a special deceleration speed that is increased or decreased from the normal deceleration speed. A technique has been proposed (see Patent Document 1). That is, this prior art attempts to shorten the time for the carriage return operation after the document reading is completed by changing the deceleration speed.

JP 2006-245935 A

  However, in the above prior art, since the time for the carriage return operation after the completion of document reading is shortened by changing the deceleration speed, a mechanism and an operation control technique for changing the carriage deceleration speed are required. Today, where the cost is high and the reading speed is required to be high, it is difficult to sufficiently improve the total reading speed for reading a document only by changing the speed when the carriage is decelerated after the document is read. There was a problem that there was.

  Accordingly, an object of the present invention is to provide an image reading apparatus, an image reading method, an image reading program, and a recording medium that read a document with high quality, high speed, and low cost by a fixed document type reading method.

  In order to achieve the above object, according to the present invention, in the sub-scanning direction orthogonal to the main scanning direction, half the designated resolution in the forward direction from the document leading end side to the trailing end side and in the returning path direction from the document trailing end side to the leading end side. Bidirectional image reading in which the traveling body is moved at a speed corresponding to the resolution of the original to read the forward path and the backward path of the original, and the forward path and the backward path are shifted in the sub-scanning direction by one pixel of the designated resolution. The operation is executed, and the forward path image data acquired by the forward path reading and the backward path image data acquired by the backward path reading are alternately synthesized for each line to obtain image data of the original.

  In the present invention, the traveling body is moved at a speed corresponding to the designated resolution, and a one-way image reading operation for reading an image of a document on either the forward path or the return path and the bi-directional image reading operation are appropriately switched. This may be a feature.

  Further, the present invention provides the bidirectional image based on whether or not the traveling speed of the traveling body corresponding to the specified resolution exceeds the limit moving speed by moving the traveling body within a range of a predetermined limit moving speed. The reading operation and the one-way image reading operation may be switched and executed.

  Further, the present invention determines an area width of a non-image line area in which the pixel value of the entire line is within a predetermined range at the leading edge and the trailing edge of the document based on the forward path image data, and at the time of reading the backward path, In the non-image line area, image reading is omitted, and a reading omission process is performed in which the moving speed of the traveling body is moved at a speed higher than that at the time of image reading. It may be generated based on the forward image data of the region.

  According to the present invention, it is possible to read a document with high quality at high speed and at low cost by a fixed document type reading method.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 7 are diagrams showing a first embodiment of an image reading apparatus, an image reading method, an image reading program, and a recording medium that read a document of the present invention with high quality at high speed and at low cost. 1 is a block diagram of a main part of an image reading apparatus 1 to which an image reading apparatus, an image reading method, an image reading program, and a recording medium according to a first embodiment of the present invention are applied.

  In FIG. 1, the image reading apparatus 1 includes a CPU (Central Processing Unit) 2, a memory 3, an operation panel 4, a reading drive unit 5, an image reading unit 6, a lamp 7, and the like. It is connected.

  The memory 3 is a volatile or non-volatile memory such as a ROM (Read Only Memory), a RAM (Random Access Memory), an EEPROM (Electrically Erasable and Programmable ROM), a hard disk, and the like. A program such as an image reading program for executing an image reading method for reading an image by bi-directional image reading processing, and system data and other data necessary for executing these programs are stored and used as a work memory for the CPU 2. The

  A CPU (image reading control means, image editing means) 2 controls each part of the image reading device 1 based on a program in the memory 3 to execute basic processing as the image reading device 1 and also performs a bidirectional image described later. An image reading method for reading is executed.

  That is, the image reading apparatus 1 includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a CD-RW (Compact Disc Rewritable), a DVD. An image reading program that executes the image reading method of the present invention recorded on a computer-readable recording medium such as a (Digital Video Disk), an SD (Secure Digital) card, or an MO (Magneto-Optical Disc) 3 is constructed as an image reading apparatus that executes an image reading method for performing image reading by a bidirectional image reading operation, which will be described later, at low cost and at high speed. This image reading program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. Can be distributed.

  The operation panel (resolution specifying means) 4 is provided with various operation keys such as a start key and function keys, and a display unit, for example, a liquid crystal display. The operation panel 4 is operated to input various commands necessary for causing the image reading device 1 to perform a desired operation using the operation keys, and the display unit displays various command contents input using the operation keys and the image reading device 1. Various information to be notified to the user is displayed. In particular, the operation panel 4 sets various conditions when reading an original G (see FIGS. 4 and 6) by bidirectional image reading, which will be described later, in particular, specifies a reading resolution (specified resolution) when reading the original. An operation is performed, and various information for reading the original is displayed on the display unit.

  The reading drive unit (running body drive means) 5 includes a drive motor and the like, and under the control of the CPU 2, the carriage 12 (see FIGS. 4 and 6) that is a running body on which the image scanning unit is mounted is moved in the sub-scanning direction. Drive in the direction perpendicular to the line direction. That is, the image reading apparatus 1 includes a contact glass 10 (see FIGS. 4 and 6) on which an original G to be read is set, and a carriage 12 on which an image scanning unit is mounted below the contact glass 10. It is arranged to be movable in the scanning direction. When reading the document G, the reading drive unit 5 first moves the carriage 12 to a preset home position Ph (see FIGS. 4 and 6) of the image reading apparatus 1 and reads the forward path from the home position Ph. The carriage 12 is moved while accelerating to the start position (usually the leading edge of the document), and the carriage 12 is moved from the forward path reading start position at a constant speed to the forward path reading end position (usually the document trailing edge). After that, the reading drive unit 5 decelerates and stops the carriage 12 and then reversely drives the motor to move the carriage 12 at a constant speed in the direction of the front end of the document with the forward reading end position as the return reading start position. The home position Ph is returned to the home position Ph by moving in the backward direction with the reading position as the backward reading end position.

  The image reading apparatus 1 is provided with a pressure plate (not shown) that covers the contact glass 10 so as to be openable and closable and presses the document G set on the contact glass 10 against the contact glass 10.

  The image scanning unit mounted on the carriage 12 normally reflects the reflected light irradiated to the original G from the lamp 7 and the lamp 7 which are light sources for irradiating the reading light in order, and reflects in the image reading direction. The lamp 7 is controlled to be lit by the CPU 2.

  The image reading unit (image reading unit) 6 includes a CCD (Charge Coupled Device) that is a photoelectric conversion element, a lens that collects reading light from the image scanning unit mounted on the carriage 12 on the CCD, and the like. Input reading light is photoelectrically converted by a CCD to output image data. In the image reading unit 6, the timing in the main scanning direction for photoelectrically converting the reading light and outputting image data is controlled by the LSYNC signal, and the timing in the sub-scanning direction for outputting image data is controlled by the FGATE signal. The

  Next, the operation of this embodiment will be described. The image reading apparatus 1 according to the present embodiment reads an image of the original G both when the carriage 12 on which the image scanning unit is mounted is moved in the forward direction and when the carriage 12 is moved in the forward direction. The image of the original G is read at a moving speed that is twice the (linear velocity), and the image data read in the forward path and the backward path are combined to obtain read image data of the original G.

  In other words, conventionally, as shown in FIG. 2, the image reading of the original G is a state in which the carriage 102 (see FIG. 3) is once moved to the home position Ph and then brought into contact with the regulating member 101 on the contact glass 100. Is moved to the document leading edge Ga of the document G set in step S1, the FGATE signal is asserted at the timing when the carriage 12 is positioned at the document leading edge Ga, and the forward movement is performed to move the carriage 12 from the document leading edge Ga to the document trailing edge Gb. Meanwhile, the image scanning unit mounted on the carriage 102 reads the image of the original G, and negates the FGATE signal at the rear end Gb of the original, thereby acquiring image data having the number of pixels corresponding to the assertion time of the FGATE signal. . Then, scanning to the rear end Gb of the original is completed, and when reading of one page of original G is completed, a return operation is performed to move the carriage 102 in the backward direction and return to the home position Ph, and the next original G is read in the same manner. A one-way image reading operation is performed. In the conventional document reading operation, as shown in FIG. 3A, the carriage 102 is moved from the document leading edge Ga to the document trailing edge Gb at a predetermined moving speed V1, and the image data of the document G is read at a reading time t1. read. In the conventional document reading operation, as shown in FIG. 3B, the moving direction of the carriage 102 moved to the document trailing edge Gb is reversed, and a predetermined moving speed Vmax (normally, image reading is performed in the backward direction). The carriage 102 is returned to the home position Ph at a return time tr1. That is, in the conventional document reading operation, the image of the document G is read at a predetermined image resolution only during the forward movement, as shown in FIG. As shown in b), only the return operation is performed to return the carriage 102 to the home position Ph. In this conventional document reading operation, as described above, when the carriage 12 is moved from the document leading edge Ga to the document trailing edge Gb to scan the document G, FGATE is scanned in the range from the leading edge pixel to the trailing edge pixel of the document G. The signal is asserted, and pixel data of the number of pixels corresponding to the assert time is read. That is, in reading an image, since the read image has the number of pixels corresponding to the assertion time of the FGATE signal, the assertion time of the FGATE signal is shortened and the low resolution image is obtained as the moving speed of the carriage 12 increases. As the moving speed of the carriage 12 becomes slower, the assertion time of the FGATE signal becomes longer and a high-resolution image can be obtained.

  However, in such a unidirectional image reading operation, even if the moving speed of the carriage 102 and the speed at the time of return are controlled to a speed Vmax that is faster than that at the time of reading, there is a limit to shortening the image reading time and If the moving speed of the carriage 102 is controlled to be high, a mechanism for controlling the speed of the carriage 102 at a high speed is required, which increases the cost.

  Therefore, as shown in FIG. 4, the image reading apparatus 1 according to the present embodiment moves the carriage 12 in the forward direction (forward direction) at a moving speed (linear speed) corresponding to a reading resolution that is half of the specified reading resolution. The image of the original G is read from the front end Ga of the original to the rear end Gb of the original, and the moving direction (line) corresponding to the reading resolution half of the designated reading resolution in the backward direction (reverse direction) by reversing the moving direction of the carriage 12. The image of the same document G is read from the document trailing edge Gb to the document leading edge Ga. Then, the image reading apparatus 1 combines the forward image data Df read in the forward direction and the backward image data Dr read in the backward direction to acquire image data for one page of the document.

  As shown in FIG. 4A, the image reading apparatus 1 is provided with a carriage 12 of a contact glass 11 so as to be movable in the sub-scanning direction of the document G, and a home position Ph and a regulating member 11 of the carriage 12 are arranged. Is provided. Then, the image reading apparatus 1 is set on the contact glass 11 in a state where the document G makes its leading end (document leading end) Ga abut against the regulating member 11 of the image reading apparatus 1.

  The image reading apparatus 1 is set after the original G is set in a state where the leading edge Ga is in contact with the regulating member 11 and necessary reading conditions (particularly, reading resolution) are set on the operation panel 4. When the start key is operated, as shown in FIG. 5, after the carriage 12 (see FIG. 6) is once moved to the home position Ph, the document reading start position (usually the document leading edge Ga of the document G, Hereinafter, it is moved to the document leading edge Ga) (step S101). When the image reading apparatus 1 moves the carriage 12 to the document leading edge Ga, the image reading apparatus 1 asserts an FGATE signal that determines the output timing of image data in the sub-scanning direction, and starts a reading operation in the forward direction (outward reading operation). At this time, the image reading apparatus 1 delays the assertion of the FGATE signal by one pixel of the designated reading resolution as shown in FIGS. 4A and 4B with respect to the unidirectional image reading operation. The required moving speed of the carriage 12 required for reading at half the specified reading resolution specified on the operation panel 4 (that is, required at the specified reading resolution in the one-way image reading operation). The moving speed is set to twice the moving speed of the carriage 12, and the reading operation in the forward direction is started (step S102).

  The image reading apparatus 1 moves the carriage 12 in the forward direction from the document leading edge Ga to the document trailing edge Gb, scans the document G in the forward direction, reads the image of the document G, and acquires the forward path image data Df (step). In step S103, when the image is read up to the trailing edge Gb of the document, as shown in FIG. 4B, the FGATE signal is negated at the trailing edge Gb of the document, the reading of the image is finished, and the carriage 12 is stopped (step S103). S104).

  Next, the image reading apparatus 1 moves the carriage 12 in the backward direction to the reading start position of the document G in the backward path (usually the document trailing edge Gb of the document G, hereinafter referred to as the document trailing edge Gb). Move (step S105). When the image reading apparatus 1 moves the carriage 12 to the document rear end Gb, the image reading apparatus 1 asserts the FGATE signal and starts a reading operation (return reading operation) in the returning direction. At this time, the image reading apparatus 1 delays the assertion of the FGATE signal by the designated reading resolution of one pixel as shown in FIG. 4C with respect to the unidirectional image reading operation. On the other hand, the double moving speed (linear velocity), that is, the reading resolution is set to half, and the backward reading operation is started (step S106).

  The image reading apparatus 1 moves the carriage 12 in the backward direction from the document trailing edge Gb to the document leading edge Ga, scans the document G in the backward direction, reads the image of the document G, and acquires the return image data Dr (step). When the image of the document G is read up to the document leading edge Ga (S107), as shown in FIG. 4C, the FGATE signal is negated at the document leading edge Ga, and the image reading is finished (step S108). The image reading apparatus 1 continues to move the carriage 12 and moves it to the home position Ph (step S109), and the forward image data Df acquired by the reading operation in the forward direction and the return image data acquired by the reading operation in the backward direction. Dr is combined to obtain read image data of one page of the document G (step S110). In the image data synthesizing process, the image reading device 1 moves the carriage 12 from the document trailing edge Gb of the document G toward the document leading edge Ga while the returning image data Dr acquired by the backward scanning operation in the reverse direction. Since the image of the original G is read, the image is reversed 180 ° from the forward image data Df obtained by reading the image of the original G while moving the carriage 12 from the front end Ga of the original to the rear end Gb of the original. After the image data Dr is rotated 180 °, the image data Dr is combined with the forward image data Df.

  That is, when the image reading apparatus 1 reads the document G, the assertion time of each FGATE signal in the forward reading operation and the backward reading operation is half of the assertion time of the FGATE signal in the one-way image reading operation. By setting the time, the number of pixels to be acquired is halved in each reading operation, and the start timing of the FGATE signal in the forward path and the backward path is delayed by the designated image resolution by 1 pixel, so that the forward path image data Df and the backward path The image data Dr is image data obtained by reading the middle of each pixel. Therefore, by superimposing the forward path image data Df acquired by the forward path reading operation and the backward path image data Dr acquired by the backward path reading operation, the same number of pixels (resolution) as the image data obtained by the unidirectional image reading operation is obtained. Image data of the number of pixels (resolution) can be obtained.

  That is, as shown in FIGS. 6A and 6B, the image reading apparatus 1 moves the carriage 12 from the document leading edge Ga to the document trailing edge Gb at a predetermined moving speed V2, and reads the document at the reading time t2. The G image data is read at a predetermined resolution, for example, half the resolution of the conventional reading operation (one-way image reading operation) shown in FIGS. Then, as shown in FIG. 6B, the image reading apparatus 1 reverses the moving direction of the carriage 12 moved to the document trailing edge Gb and moves it in the backward direction at the same moving speed V2 as the forward direction. When the image data of the document G is read at the same resolution as the forward direction at the reading time t3 and the image of the document G is read up to the document leading edge Ga, the carriage 12 is returned from the document leading edge Ga to the home position Ph at the return time tr2. That is, the bidirectional image reading operation of the image reading apparatus 1 is performed at a predetermined image resolution (for example, FIGS. 2 and 3) as shown in FIGS. 4B and 4C during both the forward movement and the backward movement. 6 (b), the image of the original G is read with substantially the same reading time as the one-way image reading operation, and only a short distance from the original tip Ga to the home position Ph is shown in FIG. As described above, as the return operation, the return time tr2 is set to be shorter than the conventional return time tr1.

  That is, in the conventional document reading operation, as shown in FIG. 7A, the total reading time is obtained by adding the document reading time t1 in the forward path and the return time tr1 in the backward path. Then, as shown in FIG. 7B, the original reading time (forward reading time) t2 in the forward path, the original reading time (return reading time) t3 in the backward path, and the short return time from the document leading edge Ga to the home position Ph. The time obtained by adding tr2 is the total reading time. In the case of the above embodiment, the forward reading speed and the backward reading speed are set to half of the conventional reading speed, so that the total reading time (the reading time t2 and the backward reading time t3 of the embodiment are added) ( t2 + t3) is approximately the same time as the conventional document reading time t1, but the return time tr2 of the embodiment is a time required to move the carriage 12 by a short distance from the document leading edge Ga to the home position Ph. On the other hand, in the conventional document reading operation, the moving direction of the carriage 12 is reversed after the document reading from the document leading edge Ga to the document trailing edge Gb in the forward path is completed, and the document trailing edge Gb and the document leading edge are further reversed. Since the time from passing through Ga to returning to the home position Ph is the return time tr1, the return time of the present embodiment Than r2 becomes significant amount longer (tr1> tr2). In the conventional reading operation, the carriage 102 is moved at a faster speed at the time of return than at the time of the image reading. However, since the image reading apparatus 1 of the present embodiment has a short return distance, the moving speed is the same as that at the time of image reading. Thus, the carriage 12 is moved.

  Note that the image reading apparatus 1 may combine the forward image data Df and the backward image data Dr in parallel with the reading operation of the document G in the backward direction. In this way, the entire image reading processing time can be further shortened.

  Further, in the above description, by delaying the assertion of the FGATE signal by one pixel at the start of document reading in the forward path and at the start of document reading in the backward path, the document reading line in the forward path and the document reading line in the backward path are mutually Although reading is performed in a complementary state, mutual complementation of reading lines in the forward path and the backward path is not limited to the method of executing the assertion of the FGATE signal at the start of reading in the forward path and the backward path with a delay of one pixel, For example, the reading lines in the forward path and the backward path may be mutually complemented by accelerating the negation of the FGATE signal one pixel earlier at the end of reading the original path and at the end of reading the original path.

  As described above, the image reading apparatus 1 according to the present exemplary embodiment has the designated resolution in the forward direction from the leading edge Ga side to the trailing edge Gb side of the document G and the returning direction from the document trailing edge Gb side to the leading edge Ga side in the sub-scanning direction. The carriage 12 is moved at a speed corresponding to half the resolution of the original to read the forward path and the backward path of the document Ga, and the forward path and the backward path are shifted in the sub-scanning direction by one pixel of the designated resolution. The bidirectional image reading operation is executed, and the forward path image data Df acquired by the forward path reading and the backward path image data Dr acquired by the backward path reading are alternately synthesized for each line to obtain the image data of the original.

  Therefore, the total reading time of the original G can be shortened by the original fixed reading method, and the original G can be read with high quality at high speed and at low cost.

  Further, according to the image reading apparatus 1 of the present embodiment, it is not necessary to perform a high speed operation dedicated to the return operation of the carriage 12 as in the prior art, and the reading drive unit 5 as a moving mechanism of the carriage 12 is simplified. Thus, the configuration can be reduced, the cost can be reduced, the operation of the carriage 12 can be stabilized, and the stabilization of the operation of the digital image data 1 can be improved.

  Further, as described above, the composition of the forward path image data Df and the backward path image data Dr may be performed in parallel with the reading operation of the document G in the backward path direction, and the synthesis of the image data is performed in the reading operation of the document G in the backward path direction. If performed in parallel, the entire image reading processing time can be further shortened.

  In the above description, the movement speed of the carriage 12 in the return operation is the same as that at the time of reading. However, the movement speed of the carriage 12 in the return operation may be controlled to be faster than that at the time of reading. In this way, the entire image reading processing time can be further shortened.

  FIG. 8 is a flowchart showing image reading processing by the image reading apparatus to which the second embodiment of the image reading apparatus, image reading method, image reading program and recording medium of the present invention is applied.

  This embodiment is applied to an image reading apparatus similar to the image reading apparatus 1 of the first embodiment. In the description of this embodiment, the reference numerals used in the description of the first embodiment are used as they are. It explains using. In FIG. 8, the same processing steps as those of the image reading processing of FIG. 5 of the first embodiment are denoted by the same step numbers, and the description thereof is omitted or simplified.

  The image reading apparatus 1 according to the present embodiment includes a bidirectional image reading operation for reading an image of the document G both when the carriage 12 moves in the document forward direction and when the carriage 12 moves in the document backward direction, and movement of the carriage G in the forward direction of the document G. A function of selectively executing a one-way image reading operation for reading an image of the document G at one of the time and the backward direction movement (usually when moving in the forward direction). The apparatus 1 is provided with a limit moving speed set in advance as the moving speed of the carriage 12 by the reading drive unit 5. Further, when the image reading apparatus 1 reads an image of the original G in the bidirectional image reading operation, the image reading device 1 uses the reading drive unit 5 at a required moving speed required by the reading resolution half of the reading resolution specified by the operation panel 4. The original G is read by moving the carriage 12.

  Then, the image reading apparatus 1 determines whether the CPU 2 determines whether the requested moving speed of the carriage 12 required by the reading resolution half of the reading resolution specified by the operation panel 4 exceeds the limit moving speed. When the moving speed is slower than the limit moving speed, the image of the original G is read by the bidirectional image reading operation. When the required moving speed exceeds the limit moving speed, the image of the original G is read by the one-way image reading operation. Read.

  That is, in the image reading apparatus 1, when the document G is set on the contact glass 10, the reading resolution is designated on the operation panel 4, and the reading start is instructed, the CPU 2 performs the operation as shown in FIG. The requested moving speed of the carriage 12 required for the reading resolution half of the reading resolution (specified resolution) specified on the operation panel 4 is slower than the limit moving speed, that is, half of the specified reading resolution. It is determined whether reading is possible at the reading resolution (step S201), and if the original G can be read at a reading resolution that is half of the specified reading resolution, a bidirectional image reading operation similar to the image reading process shown in FIG. The image of the original G is read by processing (steps S101 to S110). .

  In step S201, if reading is impossible at half the specified reading resolution, the CPU 2 once moves the carriage 12 to the home position Ph and then moves to the document leading edge Ga, which is the document reading start position. (Step S211). When the image reading apparatus 1 moves the carriage 12 to the document leading edge Ga, the image reading apparatus 1 asserts the FGATE signal and starts the reading operation in the forward direction. At this time, in the one-way image reading operation, the image reading apparatus 1 does not perform the process of delaying the assertion of the FGATE signal by the designated resolution of one pixel at the start of reading, and the operation panel 4 Is set to the required moving speed of the carriage 12 required for the reading resolution specified in (1), and the reading operation in the forward direction is started (step S212).

  The image reading apparatus 1 moves the carriage 12 from the document leading end Ga to the document trailing end Gb in the forward direction, scans the document G, reads an image of the document G, and acquires document image data D (step S213). When the image of the document G is read up to the document rear end Gb, the FGATE signal is negated at the document rear end Gb, the image reading is terminated, and the carriage 12 is stopped (step S214).

  Thereafter, the CPU 2 controls the reading drive unit 5 to reversely move the carriage 12, return it to the home position Ph, and terminate the process (step S215).

  In the above description, in the one-way image reading operation, the image of the original G is read only during the forward movement, but the image of the original G may be read only during the backward movement.

  As described above, the image reading apparatus 1 according to the present embodiment moves the carriage 12 at a speed corresponding to the designated resolution designated on the operation panel 4 and reads the image of the document G in either the forward path or the backward path. The reading operation and the bidirectional image reading operation are appropriately switched and executed.

  Accordingly, the image of the original G can be read by appropriately switching between the one-way image reading operation and the two-way image reading operation, and high-quality image reading can be performed at low cost and with improved reading speed.

  Further, the image reading apparatus 1 of the present embodiment moves the carriage 12 within a range of a predetermined limit moving speed, and based on whether or not the moving speed of the carriage 12 corresponding to the specified resolution exceeds the limit moving speed. The bidirectional image reading operation and the unidirectional image reading operation are switched. In particular, when the moving speed of the carriage 12 exceeds the limit moving speed, a one-way image reading operation is performed, and when the moving speed of the carriage 12 is equal to or lower than the limit moving speed, the bi-directional image reading operation is performed.

  Therefore, the moving speed of the carriage 12 can be suppressed and the reading drive unit 5 which is a moving mechanism of the carriage 12 can be made inexpensive. For example, when high-speed reading is required even if the reading resolution is low, the reading drive unit 5 is When the image of the original G is read by the directional image reading operation, and the required reading resolution is high and the reading speed is low, the image of the original G can be read by the bidirectional image reading operation, and the reading is performed at a lower cost. It is possible to read a high-quality image while improving the speed.

  FIG. 9 is a flowchart showing image reading processing by the image reading apparatus to which the third embodiment of the image reading apparatus, image reading method, image reading program, and recording medium of the present invention is applied.

  This embodiment is applied to an image reading apparatus similar to the image reading apparatus 1 of the first embodiment. In the description of this embodiment, the reference numerals used in the description of the first embodiment are used as they are. It explains using. In FIG. 9, the same step numbers are assigned to the same processing steps as the image reading process of FIG. 5 of the first embodiment and the image reading process of FIG. Omit or simplify.

  The image reading apparatus 1 according to this embodiment includes a bidirectional image reading operation for reading an image of a document G both when the carriage 12 moves in the document forward direction and when the carriage 12 moves in the document backward direction, and when the carriage 12 moves in the document forward direction. A function of selectively executing a one-way image reading operation of reading an image of the original G in either one of the movements in the original backward direction (usually in the forward movement direction of the original). The apparatus 1 is provided with a limit moving speed set in advance as the moving speed of the carriage 12 by the reading drive unit 5. Further, the image reading apparatus 1 is provided with a pressure plate that covers the contact glass 10 so as to be openable and closable and presses the document G set on the contact glass 10 against the contact glass 10. The bi-directional image reading operation and the unidirectional image reading operation are switched depending on whether or not to execute. That is, when the pressure plate is opened, there are many occasions when the position of the document G on the contact glass 10 changes, and when the position of the document changes in the middle of reading the image of the document G in the bidirectional image reading operation, Image quality deteriorates.

  Therefore, the image reading apparatus 1 of this embodiment performs a bidirectional image reading operation only when the pressure plate is closed.

  That is, the image reading apparatus 1 determines whether the pressure plate is open when the operation panel 4 instructs to start reading (step S301). If the pressure plate is closed, the image reading device 1 is the same as the image reading process shown in FIG. The image of the original G is read by the bidirectional image reading operation process (steps S101 to S110).

  If the pressure plate is open in step S301, the CPU 2 determines whether the reading can be performed by the one-way image reading operation only in the forward direction at the reading resolution specified by the operation panel 4 without performing the reading by the reciprocating reading operation. (Step S302) If the reading is impossible only by the one-way image reading operation, the image of the original G is read by the bi-directional image reading operation process similar to the image reading process shown in FIG. 5 (Steps S101 to S110). .

  In step S302, if reading is possible only by the one-way image reading operation, the CPU 2 once moves the carriage 12 to the home position Ph as in the case of FIG. After moving to Ga (step S211), the FGATE signal is asserted, and the reading operation in the forward direction (one direction) is started. At this time, the image reading apparatus 1 does not perform a process of delaying the assertion of the FGATE signal by the designated resolution of one pixel at the start of reading with respect to the unidirectional image reading operation, and the operation speed of the carriage 12 is controlled. The requested moving speed of the carriage 12 required for the reading resolution specified on the panel 4 is set, and the reading operation in the forward direction is started (step S212).

  The image reading apparatus 1 moves the carriage 12 from the document leading end Ga to the document trailing end Gb in the forward direction, scans the document G, reads an image of the document G, and acquires document image data D (step S213). When the image of the document G is read up to the document rear end Gb, the FGATE signal is negated at the document rear end Gb, the image reading is terminated, and the carriage 12 is stopped (step S214). Thereafter, the CPU 2 controls the reading drive unit 5 to reversely move the carriage 12 to return to the home position Ph, and ends the process (step S215).

  As described above, the image reading apparatus 1 according to the present embodiment appropriately selects the bi-directional image reading operation and the unidirectional image reading operation depending on whether or not the pressure plate covering the original G on the contact glass 10 is open. Reading.

  Therefore, it is possible to prevent the read image data from being disturbed due to the position of the original fluctuating between the reading operation in the forward pass and the return pass when the pressure plate is open, and the image quality can be reduced while reducing the total reading time at a low cost. This can be further improved.

  In addition, since the image reading on the round-trip path is performed within the possible range, the total reading processing time can be appropriately reduced at a low cost.

  FIG. 10 is a flowchart showing image reading processing by the image reading apparatus to which the fourth embodiment of the image reading apparatus, image reading method, image reading program, and recording medium of the present invention is applied.

  This embodiment is applied to an image reading apparatus similar to the image reading apparatus 1 of the first embodiment. In the description of this embodiment, the reference numerals used in the description of the first embodiment are used as they are. It explains using. In FIG. 9, the same step numbers are assigned to the same processing steps as the image reading process of FIG. 5 of the first embodiment and the image reading process of FIG. Omit or simplify.

  The image reading apparatus 1 according to the present embodiment performs a bidirectional image reading operation for reading an image of the original G both when the carriage 12 moves in the forward direction of the original and when the carriage 12 moves in the backward direction of the original. The degree of change for each pixel in the sub-scanning direction of the forward reading image data Df and the backward reading image data Dr read by both reading operations is determined. When the degree of change is large, a warning that the image change is large is issued. For example, the CPU 2 accumulates the difference value (variation value) of each pixel value at the same pixel position in the main scanning direction of adjacent lines in the sub-scanning direction of the forward reading image data Df and the backward reading image data Dr read by both reading operations. ) And the cumulative value is compared with a preset threshold value. If the cumulative value exceeds the preset threshold value, the change in the forward and backward image data on the operation panel 4 is displayed. Warning is given by a method such as displaying warning information such as large warning.

  That is, as shown in FIG. 10, the image reading apparatus 1 first moves the carriage 12 once to the home position Ph, and then moves the carriage 12 to the document leading edge Ga, which is the document reading start position, and from the document leading edge Ga to the document trailing edge. An outbound reading operation is performed to acquire outbound image data Df of the original G up to Gb (steps S101 to S104). Next, the image reading device 1 reverses the moving direction of the carriage 12 and moves the carriage 12 in the backward direction, and performs a backward reading operation for acquiring the backward image data Dr of the document G from the document trailing edge Gb to the document leading edge Ga ( Steps S105 to S108).

  Thereafter, the image reading apparatus 1 continues the movement of the carriage 12 to move it to the home position Ph (step S109), and the CPU 2 returns the forward path image data Df acquired by the forward path reading operation and the backward path image acquired by the backward path reading operation. The accumulated value (cumulative value) of the differences between the pixel values at the same pixel position in the main scanning direction of adjacent lines in the sub-scanning direction of the data Dr is calculated as a variation value, and the variation value is set as a preset reference threshold value (setting The threshold value is compared (step S401). This reference threshold value may be set as appropriate from the operation panel 4.

  If the variation value is equal to or smaller than the reference threshold value in step S401, the image reading apparatus 1 determines that there is little or no image disturbance due to document position variation during reading in the forward direction and reading in the backward direction. Then, the forward path image data Df and the backward path image data Dr inverted by 180 ° are combined to acquire the read image data of one page of the document G, and the process is terminated (step S402).

  If the fluctuation value exceeds the reference threshold value in step S401, the image reading apparatus 1 determines that the image is largely disturbed due to fluctuations in the document position and the like when reading in the forward direction and reading in the backward direction. Judgment is made by a method of displaying on the display of the operation panel 4 image abnormality information indicating that the degree of change in the image data of the forward path and the backward path is large and the read image is abnormal (step S403). This image abnormality notification is not limited to the method by display on the display of the operation panel 4, and various methods such as a notification method by voice and a notification method by e-mail can be used.

  When the image reading apparatus 1 notifies the abnormal image information, the image reading apparatus 1 combines the forward image data Df and the backward image data Dr inverted by 180 ° to acquire the read image data of the original G of one page, and performs the processing. The process ends (step S404).

  As described above, the image reading apparatus 1 according to the present embodiment issues a warning that the read image is abnormal when the forward image data Df and the backward image data Dr acquired by the bidirectional image reading operation are largely changed.

  Therefore, when the degree of change in the forward path image data Df and the backward path image data Dr is large due to the document position being misaligned during scanning, a warning that the scanned image is abnormal can be issued, and the image quality can be optimized. Therefore, usability can be improved.

  Further, if a reference threshold value that is a guideline for fluctuations in the forward path image data Df and the backward path image data Dr can be set as appropriate from the operation panel 4 or the like, the image quality can be optimized and the image reading can be performed according to the purpose of use of the image reading apparatus 1 or the like. The productivity of the operation can be appropriately improved, and the usability can be further improved.

  Further, whether or not the warning processing for abnormalities in the bi-directional image reading image data due to the document position shifting during reading is limited when the pressure plate is open, or whether the warning processing is limited when the pressure plate is open. May be appropriately selected.

  In this way, it is possible to perform appropriate processing for the fact that the position of the original G is shifted when the pressure plate is open and the image in the forward direction and the backward direction are likely to fluctuate. It is possible to improve the usability by performing the process of determining the fluctuation only when necessary, improving the processing speed and suppressing the generation of an unnecessary warning.

  Further, the number of lines used for calculating the degree of change in the image in the forward direction and the return direction (cumulative value of the difference in pixel values) is changed depending on whether the pressure plate is open (for example, when the pressure plate is closed, The number of lines used for calculating the image fluctuation may be limited to a small number of lines), or the calculation method may be different.

  In this way, it is possible to more appropriately cope with image fluctuations in the forward direction and the backward direction, and it is possible to improve the processing speed.

  FIG. 11 and FIG. 12 are flowcharts showing image reading processing by the image reading apparatus to which the fifth embodiment of the image reading apparatus, image reading method, image reading program and recording medium of the present invention is applied.

  This embodiment is applied to an image reading apparatus similar to the image reading apparatus 1 of the first embodiment. In the description of this embodiment, the reference numerals used in the description of the first embodiment are used as they are. It explains using. In FIG. 11 and FIG. 12, the same step numbers are assigned to the same processing steps as the image reading processing of FIG. 5 of the first embodiment and the image reading processing of FIG. 10 of the fourth embodiment, The description is omitted or simplified.

  The image reading apparatus 1 according to the present embodiment performs a bidirectional image reading operation for reading an image of the document G both when the carriage 12 moves in the document forward direction and when the carriage 12 moves in the document backward direction. The degree of change of each pixel at the same pixel position in the sub-scanning direction of the forward read image data Df and the backward read image data Dr is determined. When the image change is large, a warning to that effect is given, and according to the user's selection Then, it is controlled whether or not the forward read image data Df and the backward read image data Dr are combined.

  That is, as shown in FIG. 11, the image reading apparatus 1 first moves the carriage 12 to the home position Ph, and then moves it to the document leading edge Ga, which is the document reading start position, from the document leading edge Ga to the document trailing edge. An outbound reading operation is performed to acquire outbound image data Df of the original G up to Gb (steps S101 to S104). Next, the image reading device 1 reverses the moving direction of the carriage 12 and moves the carriage 12 in the backward direction, and performs a backward reading operation for acquiring the backward image data Dr of the document G from the document trailing edge Gb to the document leading edge Ga ( Steps S105 to S108).

  Thereafter, the image reading apparatus 1 continues the movement of the carriage 12 to move it to the home position Ph (step S109), and the CPU 2 returns the forward path image data Df acquired by the forward path reading operation and the backward path image acquired by the backward path reading operation. The accumulated value (cumulative value) of the differences between the pixel values at the same pixel position in the main scanning direction of adjacent lines in the sub-scanning direction of the data Dr is calculated as a variation value, and the variation value is set as a preset reference threshold value (setting The threshold value is compared (step S401). This reference threshold value may be set as appropriate from the operation panel 4.

  If the variation value is equal to or smaller than the reference threshold value in step S401, the image reading apparatus 1 determines that there is little or no image disturbance due to document position variation during reading in the forward direction and reading in the backward direction. Then, the forward path image data Df and the backward path image data Dr inverted by 180 ° are combined to acquire the read image data of one page of the document G, and the process is terminated (step S402).

  If the variation value exceeds the reference threshold value in step S401, as shown in FIG. 12, the image reading apparatus 1 causes image disturbance due to document position variation or the like when reading in the forward direction and when reading in the backward direction. The image reading apparatus 1 determines that the image is largely abnormal and notifies the image abnormality information indicating that the read image is abnormal on the display of the operation panel 4 (step S403). In the notification of abnormality, an inquiry is made as to whether or not the forward read image data Df and the backward read image data Dr are combined and stored, and the inquiry message is displayed on the display of the operation panel 4.

  When the image reading apparatus 1 notifies the image abnormality information, the image reading apparatus 1 checks whether saving of the read image is selected by operating the operation panel 4 or the like (step S501). The return image data Dr inverted by 180 ° with Df is synthesized to acquire the read image data of one page of the original G, and the process ends (step S404). If the saving of the read image is not selected in step S501, the image reading device 1 ends the process without combining and saving the forward pass image data Df and the return pass image data Dr.

  As described above, the image reading apparatus 1 according to the present embodiment issues a warning that the read image is abnormal when the forward image data Df and the backward image data Dr acquired by the bidirectional image reading operation are largely changed. In accordance with the selection, control is performed as to whether or not the forward image data Df and the backward image data Dr are combined and stored.

  Accordingly, when image fluctuations in the forward direction and the backward direction occur, it is possible to select whether or not to save the image, and it is possible to improve the usability by optimizing the image quality.

  FIG. 13 is a flowchart showing image reading processing by the image reading apparatus to which the sixth embodiment of the image reading apparatus, image reading method, image reading program, and recording medium of the present invention is applied.

  This embodiment is applied to an image reading apparatus similar to the image reading apparatus 1 of the first embodiment. In the description of this embodiment, the reference numerals used in the description of the first embodiment are used as they are. It explains using. In FIG. 13, the same processing steps as those of the image reading processing of FIG. 5 of the first embodiment are denoted by the same step numbers, and description thereof is omitted or simplified.

  The image reading apparatus 1 according to this embodiment performs a bidirectional image reading operation of reading an image of the document G both when the carriage 12 moves in the document forward direction and when the carriage 12 moves in the document backward direction. The area width of a blank area, which is a non-image line area in which the pixel values of the entire line are within a predetermined range, is determined at the leading edge and the trailing edge of G, and the FGATE signal is asserted in the blank area when reading backward. The image reading is omitted, and the reading skip process is performed in which the moving speed of the carriage 12 is moved faster than the image reading speed, and the backward image data Dr of the blank area is determined based on the forward image data Df of the blank area. Generate.

  That is, as shown in FIG. 13, the image reading apparatus 1 first moves the carriage 12 once to the home position Ph, and then moves the carriage 12 to the document leading edge Ga, which is the document reading start position, and from the document leading edge Ga to the document trailing edge. An outbound reading operation is performed to acquire outbound image data Df of the original G up to Gb (steps S101 to S104).

  When the forward reading operation is performed, the image reading apparatus 1 has a threshold Tw that is a threshold at which all pixels in one line or more can be determined as white pixels or white pixels, or a threshold that can be determined as all black pixels or black pixels. The presence / absence of an area equal to or less than a certain threshold value Tb is searched to determine that the area is a blank area, and the area width of the blank area continuous from the document leading edge Ga is stored in the memory 3 as the leading edge blank area. Similarly, the image reading apparatus 1 stores a blank area continuous from the document trailing edge Gb as a trailing edge blank area in the memory 3 (step S601).

  Next, the image reading apparatus 1 starts moving the carriage 12 in the backward direction to the document rear end Gb of the document G (step S105), and starts an image reading operation in the backward path (step S602). At this time, when the image reading apparatus 1 reads the image of the original G by the forward reading operation without asserting the FGATE signal in the trailing edge blank area stored in the memory 3 by the forward reading operation. In the image area past the trailing edge blank area, the assertion of the FGATE signal is delayed by the designated resolution of one pixel in the same manner as in the backward scanning operation, and the image area specified by the operation panel 4 is used. The required moving speed of the carriage 12 required for reading at half the specified reading resolution (double the moving speed of the carriage 12 required for the specified reading resolution in the one-way image reading operation) The movement speed is set, and the backward reading operation is performed (step S602).

  Then, when the image reading device 1 reads the backward reading operation of the image area and performs the reading operation up to the start position of the leading blank area, the image reading apparatus 1 negates the FGATE signal at the starting position of the leading blank area and performs the reading operation. The process ends (step S603), and a return operation for moving the carriage 12 to the home position Ph is performed (step S109).

  When the backward reading operation is completed, the image reading apparatus 1 combines the forward image data Df and the backward image data Dr inverted by 180 ° to acquire the read image data of the original G of one page, and the backward scanning operation. For the blank area skipped, the backward path image data Dr is generated based on the forward path image data Df of the blank area, and the forward path image data Df and the generated backward path image data Dr are synthesized (step S604). For example, the return image data Dr of the blank area is generated as the return direction image data Dr by duplicating each line of the forward image data Df of the blank area for each line.

  As described above, in the image reading apparatus 1 according to the present embodiment, the pixel values of the entire line are within a predetermined range at the front end portion and the rear end portion of the document G based on the forward pass image data Df acquired by the forward pass reading of the bidirectional image reading operation. The area width of the blank area (no image line area) is determined, and in the backward reading, the image reading in the blank area is omitted without asserting the FGATE signal, and the moving speed of the carriage 12 is set higher than that in the image reading. In addition, the reading skip process of moving at a high speed is performed, and the inbound image data Dr of the blank area is generated based on the outbound image data Df of the blank area.

  Therefore, the carriage 12 can be moved more quickly without the blank area reading operation in the backward reading operation, and the total reading processing time can be further shortened.

  In this case, if the threshold values Tw and Tb for determining whether or not to determine a blank area can be set as appropriate, the threshold value Tw and Tb can be set as appropriate according to the purpose of use of the image reading apparatus 1 and the background color of the document G. It is possible to read an image using a region intended by a person as a reading region, thereby further improving the image quality of the read image and improving the usability.

  FIG. 14 is a flowchart showing image reading processing by the image reading apparatus to which the seventh embodiment of the image reading apparatus, image reading method, image reading program, and recording medium of the present invention is applied.

  This embodiment is applied to an image reading apparatus similar to the image reading apparatus 1 of the first embodiment. In the description of this embodiment, the reference numerals used in the description of the first embodiment are used as they are. It explains using. In FIG. 14, the same step numbers are assigned to the same processing steps as the image reading process of FIG. 5 of the first embodiment and the image reading process of FIG. Omit or simplify.

  The image reading apparatus 1 according to this embodiment performs a bidirectional image reading operation of reading an image of the document G both when the carriage 12 moves in the document forward direction and when the carriage 12 moves in the document backward direction. The area width of a blank area, which is a non-image line area in which the pixel values of the entire line are within a predetermined range, is determined at the leading edge and the trailing edge of G, and the FGATE signal is asserted in the blank area when reading backward. The image reading is omitted, and the reading skip process is performed in which the moving speed of the carriage 12 is moved faster than the image reading speed, and the backward image data Dr of the blank area is determined based on the forward image data Df of the blank area. Generate. Further, the image reading apparatus 1 performs the high-speed movement of the carriage 12 without reading the blank area when the area width of the blank area on the document trailing edge Gb side exceeds a preset threshold Th. When the area width of the blank area on the document trailing edge Gb side is equal to or smaller than the threshold Th, the blank area is read.

  That is, as shown in FIG. 14, the image reading apparatus 1 first moves the carriage 12 to the home position Ph and then moves it to the document leading edge Ga, which is the document reading start position, from the document leading edge Ga to the document trailing edge. An outbound reading operation is performed to acquire outbound image data Df of the original G up to Gb (steps S101 to S104).

  When the forward reading operation is performed, the image reading apparatus 1 has a threshold Tw that is a threshold at which all pixels in one line or more can be determined as white pixels or white pixels, or a threshold that can be determined as all black pixels or black pixels. The presence / absence of an area equal to or less than a certain threshold value Tb is searched to determine that the area is a blank area, and the area width of the blank area continuous from the document leading edge Ga is stored in the memory 3 as the leading edge blank area. Similarly, the image reading apparatus 1 stores a blank area continuous from the document trailing edge Gb as a trailing edge blank area in the memory 3 (step S601).

  Next, the image reading apparatus 1 moves the carriage 12 in the backward direction to the document trailing edge Gb of the document G (step S105), and stores a blank area (rear side) on the document trailing edge Gb side stored in the memory 3. The area width of the edge blank area width) is compared with a threshold value Th set in advance and stored in the memory 3 (step S701). This threshold value Th is a process in which the carriage 12 is moved at a high speed in the trailing edge blank area, and then the carriage 12 is moved to a moving speed corresponding to the image reading operation in the image reading area following the trailing edge blank area. It is a threshold value as to whether or not the area width is appropriate.

  If the trailing edge blank area width exceeds the threshold Th in step S701, the image reading apparatus 1 does not assert the FGATE signal in the trailing edge blank area stored in the memory 3 by the forward path reading operation. Is moved faster than the moving speed when the image of the original G is read by the forward reading operation, and in the image area after the trailing edge blank area, the FGATE for the designated resolution is equivalent to one pixel as in the backward reading operation. The assertion of the signal is delayed, and the return movement reading operation is started by setting the requested moving speed of the carriage 12 required for reading at half the specified reading resolution specified by the operation panel 4 (step). S702).

  Then, the image reading apparatus 1 reads the backward reading operation of the image area, reads the image area Dr to the start position of the leading blank area, and acquires the return path image data Dr (step S107), at the starting position of the leading blank area. Then, the FGATE signal is negated to end the reading operation (step S603), and a return operation for moving the carriage 12 to the home position Ph is performed (step S109).

  When the backward reading operation is completed, the image reading apparatus 1 combines the forward image data Df and the backward image data Dr inverted by 180 ° to acquire the read image data of the original G of one page, and the backward scanning operation. For the blank area skipped, the backward path image data Dr is generated based on the forward path image data Df of the blank area, and the forward path image data Df and the generated backward path image data Dr are synthesized (step S604). For example, the return image data Dr of the blank area is generated as the return direction image data Dr by duplicating each line of the forward image data Df of the blank area for each line.

  If the trailing edge blank area width is equal to or smaller than the threshold Th in step S701, the image reading apparatus 1 includes the trailing edge blank area including the trailing edge blank area without omitting the reading operation with the trailing edge blank area width. The return path reading operation is started using the range up to the area as the reading range (step S703). That is, the image reading apparatus 1 moves the carriage 12 in the backward direction to move to the document trailing edge Gb of the document G, and reads the image of the document G from the document trailing edge Gb. Delaying the assertion of the FGATE signal by the designated resolution by one pixel and performing the backward reading operation to obtain the backward image data Dr (step S107), negating the FGATE signal at the start position of the leading blank area (step S603), A return operation for moving the carriage 12 to the home position Ph is performed (step S109).

  When the backward reading operation is completed, the image reading apparatus 1 combines the forward image data Df and the backward image data Dr inverted by 180 ° to acquire the read image data of the original G of one page, and the backward scanning operation. For the blank area skipped, the backward path image data Dr is generated based on the forward path image data Df of the blank area, and the forward path image data Df and the generated backward path image data Dr are synthesized (step S604).

  As described above, in the image reading apparatus 1 according to the present embodiment, the pixel values of the entire line are within a predetermined range at the front end portion and the rear end portion of the document G based on the forward pass image data Df acquired by the forward pass reading of the bidirectional image reading operation. The blank area (no-image line area) is determined, and when reading backward, the blank area omits image reading without asserting the FGATE signal, and the blank area on the document trailing edge Gb side is omitted. If the area width is equal to or smaller than a preset threshold Th, the blank area is read.

  Therefore, even if a blank area exists in the read image, the blank area on the side of the document trailing edge Gb is a blank area where the blank area is not skipped when the blank area is narrow. It is possible to control whether or not to skip reading based on the area width, and to suppress the operation of performing a deceleration operation immediately after acceleration of the carriage 12 in a narrow blank area, thereby reducing the load on the movement operation of the carriage 12. Thus, the reading operation can be shortened while improving the stability of the operation.

  If the threshold Th for determining whether or not to skip the blank area at the rear end can be set as appropriate from the operation panel 4 or the like, the threshold Th can be set as appropriate according to the purpose of use of the image reading apparatus 1 or the like. Usability can be improved while improving the stability of operation.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  INDUSTRIAL APPLICABILITY The present invention can be used for an image reading apparatus, an image reading method, an image reading program, and a storage medium such as a scanner apparatus, a copying apparatus, a facsimile apparatus, and a composite apparatus that efficiently and inexpensively read an image of a document.

1 is a block diagram of a main part of an image reading apparatus to which a first embodiment of the present invention is applied. Explanatory drawing of the conventional image reading processing operation. Explanatory drawing of the conventional image reading time. Explanatory drawing of the image reading process operation | movement by the image reading apparatus of 1st Example. 6 is a flowchart illustrating image reading processing according to the first embodiment. Explanatory drawing of the image reading time by the image reading apparatus of 1st Example. The comparison explanatory drawing of the image reading time of the past and 1st Example. 12 is a flowchart illustrating image reading processing according to the second embodiment. 12 is a flowchart illustrating image reading processing according to a third embodiment. 10 is a flowchart illustrating image reading processing according to a fourth embodiment. 10 is a flowchart illustrating image reading processing according to a fifth embodiment. 12 is a flowchart showing image reading processing continued from FIG. 10 is a flowchart illustrating image reading processing according to a sixth embodiment. 10 is a flowchart illustrating image reading processing according to a seventh embodiment.

Explanation of symbols

1 Image reading device 2 CPU
3 Memory 4 Operation Panel 5 Reading Drive Unit 6 Image Reading Unit 7 Lamp 8 Bus 10 Contact Glass 11 Restricting Member 12 Carriage G Original Ga Original Top Gb Original Rear End Ph Home Position

Claims (11)

  Image reading means for photoelectrically converting incident light to output image data, a light source for irradiating reading light on a document placed on a document table, and reflected light for one line in the main scanning direction from the document A traveling body on which an optical element to be introduced into the reading means is mounted; a traveling body driving means for moving the traveling body in a sub-scanning direction perpendicular to the main scanning direction; a resolution designation means for designating a document reading resolution; The traveling body driving means in the forward direction from the front end side of the document to the rear end side and the return path direction from the rear end side of the document to the front end side at a speed corresponding to half the resolution of the designated resolution designated by the designation means. Forward scanning and backward scanning, in which reflected light from the original is photoelectrically converted by the image reading means, and forward scanning and backward scanning are performed for one pixel of the designated resolution. A reading control means for performing a bi-directional image reading operation performed by shifting the image, and the forward path image data acquired by the forward path reading and the backward path image data acquired by the backward path reading are alternately combined for each line as image data of the original. And an image editing means.   The reading control means moves the traveling body at a speed corresponding to the designated resolution, and causes the image reading means to read an image of a document on either the forward path or the return path, and the bidirectional image reading operation. The image reading apparatus according to claim 1, wherein the image reading apparatus is executed by switching as appropriate.   The traveling body driving means moves the traveling body within a range of a predetermined limit moving speed, and the reading control means determines whether the moving speed of the traveling body corresponding to the specified resolution exceeds the limit moving speed. 3. The image reading apparatus according to claim 2, wherein the two-way image reading operation and the one-way image reading operation are switched based on the image.   The image editing means calculates a cumulative value of pixel value differences at the same pixel position in the main scanning direction of adjacent lines of the forward pass image data and the backward pass image data, and the cumulative value exceeds a predetermined reference threshold value. The image reading apparatus according to claim 1, wherein a predetermined warning is output when the image is read.   The image editing means determines an area width of a non-image line area where the pixel value of the entire line is within a predetermined range at the leading edge and the trailing edge of the document based on the forward path image data, and the reading control means Read skip processing for skipping image reading by the image reading means and moving the traveling speed of the traveling body at a speed faster than that at the time of image reading in the non-image line area during the backward reading. 5. The image reading device according to claim 1, wherein the image editing unit generates return image data of the non-image line area based on the forward image data. 6.   An image reading processing step for photoelectrically converting incident light into an image reading means and outputting image data; a light source for irradiating reading light to a document placed on a document table; and one line in the main scanning direction from the document A traveling body drive processing step for moving a traveling body on which an optical element for introducing reflected light into the image reading means is moved in a sub-scanning direction perpendicular to the main scanning direction; In the image reading processing step, the traveling body is moved at a speed corresponding to half the resolution of the designated resolution in the forward direction to the side and in the backward direction from the rear end side of the document to the leading side. A reading control processing step for executing a bidirectional image reading operation in which the forward reading and the backward reading are shifted by one pixel of the designated resolution in the sub-scanning direction. And image editing processing steps for alternately synthesizing the forward path image data acquired by the forward path reading and the backward path image data acquired by the backward path reading as image data of the original for each line. An image reading method characterized by the above.   In the reading control processing step, the one-way image reading operation for moving the traveling body at a speed corresponding to the designated resolution and reading the image of the document in the image reading processing step in either the forward path or the return path, and the bidirectional image The image reading method according to claim 7, wherein the reading operation is switched as appropriate and executed.   In the traveling body drive processing step, the traveling body is moved within a range of a predetermined limit moving speed, and in the reading control processing step, the moving speed of the traveling body corresponding to the designated resolution exceeds the limit moving speed. 9. The image reading method according to claim 8, wherein the bidirectional image reading operation and the unidirectional image reading operation are switched and executed based on whether or not there is.   The image editing processing step determines an area width of a non-image line area in which the pixel value of the entire line is within a predetermined range at the leading edge and the trailing edge of the document based on the forward path image data, and the reading control processing step During the backward reading, in the non-image line area, the image reading by the image reading means is omitted, and the moving speed of the traveling body in the traveling body driving processing step is moved at a speed higher than that during the image reading. 8. The read skip process is performed, and the image editing process step generates the backward image data of the non-image line area based on the forward image data of the non-image line area. The image reading method according to claim 9.   An image reading process in which the image reading means photoelectrically converts the incident light to output image data to the computer, a light source for irradiating the document placed on the document table with the read light, and one line in the main scanning direction from the document A traveling body driving process for moving a traveling body equipped with an optical element for introducing reflected light for the image reading means in the sub-scanning direction orthogonal to the main scanning direction, and the traveling body driving process to the rear end from the document front side. The image reading process performs forward reading and backward reading of the original by moving the traveling body at a speed corresponding to half the resolution of the designated resolution in the forward direction to the side and in the backward direction from the document trailing edge to the leading edge. And reading control processing for executing a bidirectional image reading operation in which the forward reading and the backward reading are shifted in the sub-scanning direction by one pixel of the designated resolution, and the forward reading Image reading program characterized by executing image editing processing and synthesizing alternately every line acquired forward image data and the backward image data obtained by 該復 path reading was as image data of the document, the.   A computer-readable recording medium on which the image reading program according to claim 11 is recorded.

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