JP2014068245A - Image reading device - Google Patents

Abstract

When a communication speed with an information processing apparatus becomes lower than a predetermined speed, it is possible to suitably suppress a document reading operation from being temporarily stopped due to a storage unit being empty without reducing the quality of a read image. Provide technology.
When a transmission speed measured by a measurement unit is less than a predetermined transmission rate, the image reading apparatus reads a reading setting accepted by a setting reception unit, a reading time of a document read by the setting unit, and a reading accepted by the setting reception unit. When the change unit (S145) for changing to a reading setting that is longer than the original reading time in the setting and the reading setting received by the setting receiving unit are changed by the changing unit, the changed reading setting is used. The image data generated according to the reading control unit that causes the reading unit to generate image data (S130) and the changed reading setting is matched with the image data obtained by the reading setting received by the setting receiving unit. And an image processing unit that performs processing (S155).
[Selection] Figure 4

Description

  The invention disclosed in this specification relates to an image reading apparatus that reads an image of a document and transmits the read image to an external device such as a PC.

  2. Description of the Related Art Conventionally, an image reading apparatus that performs so-called PC scanning in which data communication is performed with an external apparatus such as a PC via a network and a read image read is transmitted to the external apparatus is known (for example, Patent Document 1). In the image reading apparatus, in the PC scan, the read image read is stored in an internal memory inside the apparatus, and the read image is deleted from the internal memory when the read image is transmitted to the external apparatus. Therefore, when the transmission speed for transmitting the read image to the external device is slower than the read speed for reading the read image, and the capacity of the read image stored in the internal memory exceeds the capacity of the internal memory, The reading operation was temporarily stopped.

  When the reading operation of the image reading apparatus is temporarily stopped, when the reading operation is stopped or when the reading operation is resumed, the reading speed is changed, so that the reading image is likely to be misaligned. There has been a problem that the image quality deteriorates. Therefore, the prior art discloses a technique for preventing the reading operation of the image reading apparatus from being temporarily stopped by reducing the reading speed in advance when the transmission speed is slower than the reading speed. Has been.

Japanese Patent Laid-Open No. 2002-300353

  The user wants the image reading apparatus to read an image of a document under the set reading setting, and transmits the read image read to an external apparatus such as a PC to the external apparatus. However, if the reading speed is reduced in the PC scan as in the prior art, the result is the same as when the image of the document is read with a reading setting different from the reading setting intended by the user. This causes a problem that the image of the original cannot be read.

  In this specification, in an image reading apparatus that performs PC scanning, even when a transmission speed for transmitting a read image to an external apparatus is slower than a reading speed for reading a read image, an image of a document is read with a read setting set by a user. Provide technology.

An image reading device disclosed in this specification includes a reading unit that reads an image of a document and generates image data, a setting reception unit that receives a reading setting when the reading unit reads an image of the document, and the image data In an image reading apparatus comprising: a storage unit that stores data; and a transmission unit that transmits image data stored in the storage unit to an external device. A transmission speed when the transmission unit transmits the image data to the external device. A measurement unit that measures the reading setting, and when the transmission rate measured by the measurement unit is less than a predetermined transmission rate, the reading setting received by the setting reception unit is the document reading time of the reading unit, and the setting reception unit A changing unit that performs a change process for changing to a reading setting that is longer than the original reading time in the reading setting received by the reading setting, and the reading setting received by the setting receiving unit includes the original to the reading unit. A reading control unit that causes the reading unit to generate image data in accordance with the changed reading setting when the reading unit is changed and the reading setting is changed by the changing unit. An image processing unit that performs image processing on the image data generated according to the read setting performed so as to match the image data obtained by the reading setting received by the setting receiving unit, and the reading control The unit causes the storage unit to store the image data processed by the image processing unit.
According to this configuration, when the transmission speed is lower than the predetermined transmission speed, in addition to increasing the document reading time of the reading unit, time required for image processing is added. Therefore, as compared with the case where the document reading time of the reading unit is simply increased, the time required until image data is stored in the storage unit is further increased, and it is possible to reduce the absence of the storage unit. Further, since the image data with the reading setting accepted by the setting receiving unit is obtained by the image processing, the quality of the read image is not deteriorated by changing the reading setting. That is, even when the communication speed with the information processing apparatus becomes lower than a predetermined speed, the image of the original is read with the reading setting set by the user, and the image data desired by the user is obtained.

In the image reading apparatus, image data for each part of the image generated in the reading unit is sequentially stored in the storage unit, and the transmission unit is configured to read the original image when the reading unit reads the image of the document. The image data for each part stored in the storage unit may be sequentially transmitted to the external device.
According to this configuration, the reading of the image of the document and the transmission of the image data for each part are processed in parallel. For example, the storage unit does not have to have a storage capacity for one document, Cost reduction of the image reading apparatus can be expected.

In the image reading apparatus, the reading setting includes a resolution setting, and the changing unit changes the resolution to a resolution higher than the resolution received by the setting receiving unit in the changing process, and the image processing unit In the image processing, the image data obtained by the resolution changed by the changing unit may be converted into image data having the resolution received by the setting receiving unit.
According to this configuration, by performing the conversion process related to the resolution of the image data as the image process, it is possible to suitably lengthen the time until the image data is stored in the storage unit. In this case, image data with the same resolution as the setting accepted from the user can be obtained without reading the document with the resolution accepted from the user, and image data different from the user's intention is prevented from being output. it can.

In the image reading apparatus, the reading setting includes a setting for single-color reading or multi-color reading, and the changing unit receives the single-color reading in the changing process when the setting receiving unit receives the single-color reading. The reading setting may be changed to multi-color reading, and the image processing unit may convert image data obtained by the multi-color reading into image data obtained by the single-color reading in the image processing.
According to this configuration, as a change related to the reading setting, it is possible to suitably lengthen the time until image data is stored in the storage unit by performing conversion processing from single color reading to multiple color reading. At that time, even if the original is not read by the monochrome reading accepted from the user, the image data obtained by the monochrome reading accepted from the user can be obtained, and it is possible to prevent the output of image data different from the user's intention. .

In the image reading apparatus, the reading setting includes a setting of resolution and single color reading or multi-color reading, and the changing unit is higher than the resolution received by the setting receiving unit in the changing process. When there is no resolution and the setting reception unit accepts single-color reading, the reading setting is changed to multi-color reading, and the image processing unit obtains image data obtained by the multi-color reading in the image processing. May be converted into image data obtained by monochromatic reading.
According to this configuration, even when there is no resolution higher than the resolution received by the setting reception unit, by changing from single-color reading to multiple-color reading, for example, from monochrome reading for reading a document in single color, For example, by changing to color reading in which a document is read with a plurality of colors of R (red), G (green), and B (blue), the time until image data is stored in the storage unit is preferably lengthened. be able to.

In the image reading apparatus, a designation receiving unit that receives designation of a reading range that is a range in which the reading unit reads a document, a conveyance unit that conveys the document, and a leading end of the document conveyed by the conveyance unit. A leading edge sensor for detecting the reading range based on detection of the leading edge of the document by the leading edge sensor, and accepting the changed reading setting outside the reading range. You may make it return to the said reading setting which the part received.
According to this configuration, when reading is performed with the reading setting changed by the changing unit even outside the reading range, reading from when the document is fed to when the document is discharged is compared with reading with the reading setting received by the setting receiving unit. The total time it takes may increase. Therefore, outside the reading range, the total reading time can be shortened by returning the changed reading setting to the reading setting accepted by the setting receiving unit.

The image reading apparatus may further include a transport unit that transports a document and a document sensor that detects a subsequent document following the document, and the change unit is configured to detect the subsequent document when the document sensor detects the subsequent document. The changed reading setting may be returned to the reading setting accepted by the setting receiving unit during the conveyance period in which the subsequent document is conveyed by the conveying unit until the reading of the subsequent document is started.
According to this configuration, the period from the detection of the subsequent document by the sensor to the start of reading of the subsequent document corresponds to the conveyance period of the subsequent document, and the document reading is not performed. Therefore, during the conveyance period, the changed reading setting is returned to the reading setting accepted by the setting receiving unit, whereby the total time required for reading when there are a plurality of reading documents can be shortened.

  ADVANTAGE OF THE INVENTION According to this invention, when the communication speed with information processing apparatus becomes slower than predetermined speed, it can suppress suitably that the quality of a read image falls.

FIG. 3 is a perspective view illustrating an appearance of the multifunction machine according to the first embodiment. Schematic sectional view of an image reading device of a multifunction machine Block diagram schematically showing the electrical configuration of the MFP 6 is a flowchart schematically showing a reading process in the first embodiment. Table showing reading settings in the first embodiment Flowchart schematically showing image data transmission processing 6 is a flowchart schematically showing a reading process in the second embodiment. Table showing reading settings in Embodiment 2 10 is a flowchart schematically showing a reading process in the third embodiment.

<Embodiment 1>
Next, Embodiment 1 will be described with reference to FIGS.

1. 1 is a multifunction peripheral device having a printer function, a scanner (document reading) function, a copy function, a facsimile function, and the like, and is an example of an image forming apparatus.

  As shown in FIG. 1, the multifunction machine 1 includes an image reading device 3 for reading a document above the main body 2. As shown in FIG. 2, the image reading device 3 includes a reading unit 30, a carriage 34, an automatic document feeder (ADF) device 40, a document placing unit 50, a reading drive unit 60 (see FIG. 3), and the like. . As an image reading method, the image reading device 3 is moved by a moving reading (hereinafter referred to as “FB (flood bed) reading”) in which an image is read by moving the carriage 34, and conveyed by conveying units 44 and 45 (see FIG. 2). A conveyance reading (hereinafter referred to as “ADF reading”). The image reading device 3 is not limited to a part of the multifunction device 1. For example, the image reading device may be a single scanner device or a copier.

  As shown in FIG. 2, the document placement section 50 includes an underframe 51, a first platen glass 52 made of a transparent glass plate, a second platen glass 53, and an intermediate frame disposed between the glasses 52 and 53. 54. The upper surface of the first platen glass 52 is covered with a rotatable document cover 48.

  Further, a home position HP detection mark 55 is provided on the intermediate frame 54, and the mark 55 includes a white tape 55A and a black tape 55B arranged in the sub-scanning direction (the direction of arrow A in FIG. 2). A position where the data read by the reading unit 30 changes from black to white (or from white to black) is detected as the home position HP. Here, the home position HP may be a standby position where the reading unit 30 waits when the reading unit 30 is not performing FB reading, and a reference for movement control of the carriage 34 when performing FB reading. It is assumed to be a position.

  The document cover 48 is pivotable between a closed posture covering the first platen glass 52 and an open posture opening the first platen glass 52 (the operation unit 11 and the display unit). The side on which 12 etc. are provided is connected to the front side). An ADF device 40 is provided on the document cover 48.

  As shown in FIG. 2, the ADF device 40 includes an ADF cover 41, a document tray 42, a transport path 43, various rollers such as a transport roller 44, a paper feed roller 44 </ b> A, and a paper discharge roller 45, and the top surface of the document cover 48. Including a paper discharge tray 46. The ADF device 40 conveys the originals 5 placed on the original tray 42 one by one, passes them over the second platen glass 53, and discharges them to the paper output tray 46. Further, a rear sensor (an example of a leading edge sensor) 47 such as a photo sensor for detecting the document 5 conveyed by the conveyance roller 44 and a photo sensor for detecting the document 5 set on the document tray 42 are used. A front sensor (an example of a document sensor) 49 is provided. Here, the transport roller 44, the paper feed roller 44 </ b> A, and the paper discharge roller 45 are examples of a transport unit that transports the document 5.

  The reading unit 30 is provided below the document placing unit 50 as shown in FIG. Here, the reading unit 30 is configured to read a document by a CIS (Contact Image Sensor) method. The reading unit 30 linearly reflects reflected light reflected by a linear image sensor 33 in which a plurality of light receiving elements are linearly arranged in the direction perpendicular to the paper surface, a light source 31 including RGB light emitting diodes, a document 5, and the like. A rod lens array 32 that forms an image on each light receiving element of the image sensor 33 is included. The carriage 34 that holds the reading unit 30 is coupled to the timing belt 35, and moves in the arrow A direction and the B direction as the timing belt 35 moves. The timing belt 35 is driven by a read driving unit 60 described later via a sprocket or the like (not shown). The reading unit 30 is not limited to the CIS method, and may be a so-called CCD method using a reduction optical system and a CCD (charge coupled device) image sensor.

  When reading the document 5 placed on the first platen glass 12, that is, when executing the FB reading, the reading unit 30 uses the carriage 34 coupled to the timing belt 35 to move the first platen glass from the home position HP. The original 5 is read while being conveyed at a constant speed in a direction parallel to the board surface 52 (direction A in FIG. 2). At this time, the reading range in the moving direction of the carriage 34 is, for example, from the reading start position PS to the reading end position PE shown in FIG.

  On the other hand, when reading the document 5 conveyed by the ADF device 40, that is, when executing the ADF reading, the reading unit 30 is held at the conveyance reading position RP directly below the second platen glass 53 by the carriage 34. 5 is read.

  Further, on the front side of the multifunction machine 1, an operation unit 11 including various buttons and a display unit 12 including, for example, a liquid crystal display are provided. The operation unit 11 includes a start button 11A for starting a reading operation.

2. As shown in FIG. 3, the multifunction device 1 includes a CPU 20 (an example of a change unit and a reading control unit), a ROM 21, a RAM 22, an NVRAM (nonvolatile memory) 23, a network interface (a transmission unit and setting reception). 24) and a facsimile interface 25, including a communication speed measuring unit (an example of a measuring unit) 26, an image processing unit 27, a reading unit 30, an image forming unit 10, an operation unit 11, a display unit 12, and a rear sensor. 47, the front sensor 49, the reading drive unit 60, and the like are connected.

  Various programs for controlling the operation of the multifunction device 1 are stored in the ROM 21, and the CPU 20 controls each unit while storing the processing results in the RAM 22 or the NVRAM 23 according to the programs read from the ROM 21. .

  A network interface (hereinafter referred to as “network I / F”) 24 is connected to an external computer (an example of an external device), which is an information processing device, via a communication line (not shown). Mutual data communication is possible via / F24. For example, the network I / F 24 receives, from the computer PC, a reading setting when the reading unit 30 reads an image of the document 5, for example, at least one of the reading resolution and the number of reading colors. Here, the number of read colors means single-color reading (hereinafter referred to as “monochrome reading”) or multi-color reading (hereinafter referred to as “color reading”).

  The network I / F 24 transmits the image data read by the reading unit 30 to the computer PC. In this case, in this embodiment, image data is transmitted to the computer PC by using several lines, for example, three lines of image data as a transmission data unit. In other words, when at least three lines of image data are stored in the communication buffer 22B described below, the image data is transmitted to the computer PC. Note that the transmission data unit of image data is arbitrary.

  The facsimile interface 25 is connected to a telephone line (not shown), and facsimile data can be communicated with an external facsimile apparatus or the like via the facsimile interface 25.

  The image forming unit 10 includes a well-known charging unit, exposure unit, photoconductor, developing unit, transfer unit, and fixing unit. Based on image data of an image (original) read by the image reading device 3, the image forming unit 10 Is formed on the paper.

  The RAM 22 includes a reading buffer 22A and a communication buffer (an example of a storage unit) 22B. The reading buffer 22A stores image data generated by the reading unit 30. The communication buffer 22B receives the image data from the reading buffer 22A and temporarily stores the image data when the image data is transmitted to the external computer PC via the network I / F 24.

The communication speed measuring unit 26 includes a timer 26A, and measures a transmission speed S (kilobyte / second: KB / s) when image data is transmitted to the computer PC through the network I / F 24. The transmission speed S is measured, for example, every time image data of a predetermined amount DM (KB) is transmitted from the network I / F 24 to the computer PC. At this time, a time KT (s) from when the predetermined amount DM of image data is transmitted until the network I / F 24 receives a signal confirming reception of the image data from the computer PC is counted by the timer 26A. Then, the transmission speed S is calculated by Equation 1.
S = DM / (KT / 2) ...... Equation 1
In the present embodiment, the predetermined amount DM is an amount of image data for several lines, for example, three lines.

  The CPU 20 controls various processes related to the multifunction machine 1. Further, the CPU 20 executes a reading process described below as a process related to the image reading device 3.

3. Document Reading Processing Next, document reading processing according to the first embodiment will be described with reference to FIGS. The document reading process is executed in response to, for example, the network I / F 24 receiving a reading instruction and reading setting from the computer PC. At that time, each process related to the document reading process is mainly executed by the CPU 20 in accordance with a predetermined control program stored in the ROM 21 or the like, for example. In the first embodiment, as an example of a reading setting that is changed according to the communication speed S, an example in which sub-scanning reading resolution (an example of resolution) is assumed as illustrated in FIG. 5 will be described. Further, an example will be described in which it is assumed that monochrome reading is specified as the reading command, reading of the document 5 is specified at a reading resolution of “100 dpi”, and ADF reading is specified as the reading method.

  Note that the present invention is not limited to this, and the document reading process of the first embodiment can be applied even when at least one of the main scanning reading resolution and the sub scanning reading resolution is set as the reading resolution. Even when color reading is designated, the document reading process of the first embodiment can be applied.

  Further, it is assumed that the reading process of the image data by the reading unit 30 and the transmission process of the image data to the computer PC by the network I / F 24 are performed independently. FIG. 4 shows the document reading process for convenience, and the order in which each process in the document reading process is actually executed may not match the order shown in FIG.

  In the document reading process, the CPU 20 first performs setting for the reading unit 30 to read the document 5 at a reading resolution of “100 dpi” received from the computer PC (step S105). Next, the reading drive unit 60 is controlled to drive the paper feed roller 44A to start conveying the document 5 (step S110). Next, based on the detection signal from the rear sensor 47, the CPU 20 determines whether the rear sensor 47 has detected the leading edge of the document 5 (step S115).

  When it is determined that the leading edge of the document 5 is not detected (step S115: NO), the CPU 20 further conveys the document 5. On the other hand, if it is determined that the leading edge of the document 5 has been detected (step S115: YES), the CPU 20 controls the reading unit 30 to read the image of the document 5 line by line according to the reading setting (step S120). .

  Next, the CPU 20 stores the image data read by the reading unit 30 in the reading buffer 22A (step S130). When image data for several lines, for example, three lines, is stored in the reading buffer 22A in the reading buffer 22A, the image data for three lines is moved to the communication buffer 22B. Then, the image data is transmitted to the computer PC via the network I / F 24 as described above using the image data for three lines as a transmission unit. At this time, the communication speed measuring unit 26 calculates the transmission speed S by the above-described equation 1.

  The CPU 20 acquires the transmission speed S calculated by the communication speed measuring unit 26 (step S135), and determines whether or not the transmission speed S is less than a prescribed speed, for example, 100 KB / s (step S140).

  As shown in C2 of FIG. 5, when it is determined that the transmission speed S is less than 100 KB / s and the transmission speed S is greater than 50 KB / s, the sub-scanning reading resolution is changed from “100 dpi”. For example, it may be changed to “200 dpi”.

  When it is determined that the acquired transmission speed S is 40 KB / s and the transmission speed S is less than 100 KB / s (step S140: YES), as shown in C3 of FIG. The resolution is changed from “100 dpi” to, for example, “300 dpi” (step S145). Here, a method of changing the sub-scanning reading resolution from “100 dpi” to “300 dpi” will be described. For example, by reading three lines where a predetermined interval is read by one line, the operation is tripled at the predetermined interval, and the time required for reading can be increased.

  Then, it is determined whether there is image data read at “300 dpi” (step S150). If it is determined that there is image data read at “300 dpi” (step S150: YES), the CPU 20 performs image processing so that the image data read at “300 dpi” matches the image data read at “100 dpi”. The image is processed by the unit 27 (step S155).

  Specifically, in the image data read at “300 dpi”, image processing is performed in which three lines are changed to one line by thinning out two lines from a bundle of three lines. As a result, the image data read at “300 dpi” is processed into image data read at “100 dpi”. As a result, it can be expected that the time from when the image of the document is read to when the image data is stored in the communication buffer 22B is longer than when the reading resolution is not changed.

  In step S160, image data that matches the image data read at “100 dpi” processed in step S155 is stored in the communication buffer 22B (step S160).

  On the other hand, if it is determined that the transmission speed S is not less than 100 KB / s (step S140: NO), this corresponds to C1 in FIG. 5, and the CPU 20 does not change the sub-scanning reading resolution. If it is determined in step S150 that there is no image data read at “300 dpi” (step S150: NO), the CPU 20 stores the image data in the communication buffer 22B (step S160). That is, when the sub-scanning reading resolution is not changed, the image data stored in the reading buffer 22A is stored in the communication buffer 22B.

  Here, a transmission process for transmitting the image data stored in the communication buffer 22B from the multifunction device 1 to the computer PC will be described with reference to FIG. The transmission process is executed in parallel with the reading process.

  First, the CPU 20 determines whether there is image data for a predetermined number of lines in the communication buffer 22B (S305). When determining that there is no image data for the predetermined number of lines in the communication buffer 22B (S305: NO), the CPU 20 waits until image data for the predetermined number of lines is stored in the communication buffer 22B. On the other hand, when determining that there is a predetermined number of lines of image data in the communication buffer 22B (S305: YES), the CPU 20 transfers the image data stored in the communication buffer 22B to the computer PC via the network I / F 24. Transmit (S310), and the transmission process ends.

  Next, the CPU 20 determines based on the detection signal from the rear sensor 47 whether or not the rear end of the document 5 is detected by the rear sensor 47 (step S165). If it is determined that the trailing edge of the document 5 is not detected (step S165: NO), the CPU 20 returns to the process of step S120 and further causes the reading unit to read the document 5. On the other hand, when it is determined that the trailing edge of the document 5 is detected (step S165: YES), the CPU 20 determines whether there is a subsequent document based on the detection signal from the front sensor 49 (step S170).

  If it is determined that there is a subsequent document (step S170: YES), the CPU 20 returns to the process of step S110 and drives the paper feed roller 44A to start conveying the subsequent document. On the other hand, if it is determined that there is no subsequent document (step S170: NO), the CPU 20 stops the motor 62, stops the conveyance of the document by the conveyance units 44, 44A, 45, and ends the document reading process.

5. Effect of Embodiment 1 According to the present embodiment, when the transmission speed S is less than a predetermined transmission speed, the reading setting accepted by the network I / F 24 is changed to a sub-scanning reading resolution higher than the sub-scanning reading resolution, In addition to lengthening the document reading time of the reading unit 30, a time required for image processing for returning the changed sub-scanning reading resolution to the accepted sub-scanning reading resolution is added. Therefore, as compared with the case where the document reading time of the reading unit 30 is simply increased, it takes a longer time to store the image data in the communication buffer 22B, and it is possible to reduce the absence of the communication buffer 22B. .

  Further, since image data at the sub-scanning reading resolution accepted by the network I / F 24 is obtained by image processing, the quality of the read image is not deteriorated by changing the sub-scanning reading resolution. That is, when the communication speed S with the computer PC becomes lower than the predetermined speed, it is possible to suitably suppress the temporary stop of the document reading operation because the transmission buffer 22B is not empty without reducing the quality of the read image. .

  In addition, as the image processing, by performing processing for returning the sub-scanning reading resolution of the image data from “300 dpi” to the reading setting “100 dpi”, the time until the image data is stored in the transmission buffer 22B is preferably lengthened. be able to. In this case, image data with the same resolution as the setting accepted from the user can be obtained without reading the document with the resolution accepted from the user, and image data different from the user's intention is prevented from being output. it can.

<Embodiment 2>
Next, Embodiment 2 will be described with reference to FIGS. In the second embodiment, the reading setting changed according to the communication speed S is different from that in the first embodiment. In the second embodiment, an example in which the setting of the number of reading colors for monochrome reading or color reading is assumed will be described. Therefore, the same members as those in the first embodiment are denoted by the same member numbers, and the same processes are denoted by the same process numbers, and the description thereof is omitted. Further, as in the first embodiment, an example in which monochrome reading is designated and ADF reading is designated as a reading method will be described.
As in FIG. 4, FIG. 7 shows the document reading process for convenience, and the order in which each process in the document reading process is actually executed may not match the order shown in FIG. is there.

  In the document reading process, the CPU 20 first makes a setting for the reading unit 30 to read the document 5 by “monochrome reading” received from the computer PC (step S205). Next, the CPU 20 executes the processing from step S110 to step S140 as in the first embodiment. If the CPU 20 determines in step S140 that the transmission speed S is less than 100 KB / s (step S140: YES), the CPU 20 corresponds to C2 in FIG. The "monochrome reading" is changed to, for example, "color reading" (step S245).

  Here, a method for changing from “monochrome reading” to “color reading” will be described in detail. In monochrome reading, one line to be read is read, for example, by turning on a G light emitting diode. In the color reading, not only the G light emitting diode is turned on but also the R light emitting diode is emitted, and the B light emitting diode is also emitted for reading the same one line to be read. Further, it is impossible to read the G color, the R color, and the B color by lighting them simultaneously. For this reason, in color reading, it takes about three times as much time to read one line to be read as compared to monochrome reading, and the time required for reading can be increased.

  Next, the CPU 20 determines whether or not there is image data read by “color reading” (step S250). If it is determined that there is image data read by “color reading” (step S250: YES), “ The image processing unit 27 performs image processing so that the image data read by “color reading” matches the image data read by “monochrome reading” (step S255).

  Specifically, in the reading buffer 22A, image data read by turning on a light emitting diode of G color and image data read by turning on a light emitting diode of R color for the same one line to be read. The image data read by turning on the B light emitting diode is stored. Here, for example, the image processing unit 27 deletes the image data read by turning on the R light emitting diode and the image data read by turning on the B light emitting diode, and the G light emitting diode is removed. Image processing is performed in which only the image data read by lighting is left in the reading buffer 22A.

  Then, as in the first embodiment, the CPU 20 executes the processing from step S160 to step S170 and determines that there is no subsequent document (step S170: NO), the CPU 20 stops the motor 62 and stops the conveyance unit. The conveyance of the document by 44, 44A, 45 is stopped, and the document reading process is terminated.

  On the other hand, when it is determined in step S140 that the transmission speed S is not less than 100 KB / s (step S140: NO), the CPU 20 keeps “monochrome reading” as the reading method related to the number of read colors. When it is determined that there is no image data read by “color reading” (step S250: NO), the CPU 20 executes the processing from step S160 to step S170 as in the first embodiment.

6). Effects of Second Embodiment In the second embodiment, when the network I / F 24 receives “monochrome reading” from the computer PC, the CPU 20 sets “monochrome reading” to “color reading” when the transmission speed S is less than a predetermined transmission speed. Change to "Read". In the image processing, the image processing unit 37 converts the image data obtained by “color reading” into image data obtained by “monochrome reading”. Therefore, as a change related to the reading setting, by performing conversion processing from “monochrome reading” to “color reading”, it is possible to suitably lengthen the time until image data is stored in the transmission buffer 22B. At this time, even if the original is not read by “monochrome reading” received from the user, image data obtained by “monochrome reading” received from the user is obtained, and image data different from the user's intention is output. Can be prevented.

<Embodiment 3>
Next, a third embodiment will be described with reference to FIG. The third embodiment can cope with the case where there is no resolution changed in accordance with the communication speed S in the first embodiment. Therefore, the same members as those in the first embodiment are denoted by the same member numbers, and the same processes are denoted by the same process numbers, and the description thereof is omitted. In addition, as in the first embodiment, an example in which monochrome reading is designated and ADF reading is designated as a reading method will be described.

  Similar to the first embodiment, the processing from step S105 to step S140 is executed. If the CPU 20 determines in step S140 that the transmission speed S is less than 100 KB / s (step S140: YES), whether or not the multifunction device 1 has a resolution higher than the resolution received from the computer PC. Is determined (step S443).

  When the multifunction device 1 has a resolution higher than the resolution received from the computer PC (step S443: YES), the CPU 20 changes the resolution to a higher resolution than the designated resolution received from the computer PC (step S446). ), It is determined whether or not the image data with the changed reading setting received from the computer PC is stored in the reading buffer 22A (step S450).

  On the other hand, when the multifunction device 1 does not have a resolution higher than the resolution received from the computer PC (step S443: NO), the CPU 20 performs the “color reading” on the designated “monochrome reading” received from the computer PC. (Step S449), and the process of S450 is executed. In the process of step S449, for example, the maximum resolution of the multifunction device 1 is “600 dpi”, “600 dpi” is specified in the reading command, and monochrome reading is specified. In this case, the resolution of “600 dpi” cannot be changed to a higher resolution, but the time required for reading can be increased by changing “monochrome reading” to “color reading”.

  When it is determined that the image data with the changed reading setting received from the computer PC is stored in the reading buffer 22A (step S450: YES), and when it is determined that the resolution has been changed (step S453: YES), the CPU 20 causes the image processing unit 27 to perform image processing so as to return to the designated resolution received from the computer PC in the same manner as S155 in the first embodiment (step S456), and executes the processing from S160 onward. To do. If it is determined that the resolution has not been changed (step S453: NO), the CPU 20 returns to the designated “monochrome reading” received from the computer PC in the same manner as in S255 of the second embodiment. The image processing unit 27 performs image processing (step S459), and the processing after S160 is executed.

  If it is determined in step S140 that the transmission speed S is not less than 100 KB / s (step S140: NO), the CPU 20 executes the process of step S450. On the other hand, if it is determined that the image data with the changed reading setting received from the computer PC is not stored in the reading buffer 22A (S450: NO), the processing after step S160 is executed.

7). Effects of Embodiment 3 When the maximum resolution of the multifunction device 1 is, for example, “600 dpi”, “600 dpi” is specified in the reading command, and monochrome reading is specified, the resolution of “600 dpi” is changed to a higher resolution. However, it is possible to increase the time required for reading by changing “monochrome reading” to “color reading”. For this reason, it is possible to suitably lengthen the time until image data is stored in the transmission buffer (an example of a storage unit) 22B.
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the second embodiment, when “color reading” is designated and the transmission speed S is less than the predetermined transmission speed (step S140: YES), the CPU 20 sets the resolution in the same manner as in the first embodiment. By increasing the time, the time until the image data is stored in the transmission buffer 22B may be lengthened.

  (2) In each of the embodiments described above, the network I / F (an example of a designation receiving unit) 24 accepts designation of a reading range that is a range in which the reading unit 30 reads the document 5, and a CPU (an example of a changing unit). 20 is configured to recognize the reading range based on the detection of the leading edge of the document 5 by the rear sensor 47 (an example of the leading edge sensor). Then, outside the reading range, the CPU 20 may return the reading setting changed in step S145 or step S245 to the reading setting received by the network I / F (an example of a setting receiving unit) 24.

  The reading range is recognized by a known method in which the leading edge of the document 5 is detected and the leading edge of the document 5 is used as a reference. That is, the CPU 20 starts the reading operation by the reading unit 30 based on the detection of the leading edge of the document 5 by the rear sensor 47, and changes in the amount of light received by the reading unit 30 when the leading edge of the document 5 reaches the transport reading position RP. The leading edge of the document 5 is detected. Then, the CPU 20 recognizes whether or not it is the reading range from the distance in the document conveying direction from the leading edge of the document 5 to the reading range and the document conveying speed.

  When reading with the reading setting changed by the CPU 20 even outside the reading range, compared to reading with the reading setting accepted by the network I / F 24, the total time required for reading from feeding the document 5 to discharging the document 5 May become longer. For this reason, outside the reading range, the changed reading setting is returned to the reading setting accepted by the network I / F 24, so that the transmission buffer 22B runs out of space and the reading of the original is temporarily stopped while suppressing the reading operation. The total time can be shortened.

  (3) In each of the above embodiments, the CPU (an example of the changing unit) 20 conveys the subsequent document by the time when the subsequent document is detected by the front sensor (an example of the document sensor) 49. In the conveyance period in which the subsequent document is conveyed by the units 44 and 44A, the reading setting changed in step S145 or step S245 may be returned to the reading setting accepted by the network I / F 24.

  The period from the detection of the subsequent document by the front sensor 49 to the start of the reading of the subsequent document corresponds to the conveyance period of the subsequent document, and the document reading is not performed. Therefore, during the conveyance period, by returning the changed reading setting to the reading setting accepted by the network I / F 24, there is no space in the transmission buffer 22B. The total time required for reading when there is a read document can be shortened.

(4) In each of the above embodiments, the transmission rate S of the image data is measured by the communication rate measuring unit 26 every time the read image data of a predetermined amount DM is transmitted from the network I / F 24 to the computer PC. An example is shown, but the present invention is not limited to this. For example, when a reading instruction is received from the computer PC, the transmission speed S may be measured by transmitting data dedicated to transmission speed measurement to the computer PC, for example, before starting the image reading operation. Thereafter, the transmission speed S may be measured at predetermined time intervals, or the transmission speed S may be measured every time image data is transmitted as in the first and second embodiments.
In this case, the reading setting can be changed before the start of the image reading operation, and the image reading can be performed with the changed reading setting from the first one-line image reading.

  (5) In each of the above embodiments, an example in which ADF reading is designated as the reading method has been shown, but the present invention is not limited to this. Even when FB reading is designated as the reading method, the document reading process of each embodiment can be applied. When FB reading is designated, for example, the processing related to driving of the conveyance units 44, 44 </ b> A, and 45 may correspond to the movement processing of the carriage 34. For example, the processing in step S110 and step S115 corresponds to moving the carriage 34 from the home position HP to the document reading start position PS. Further, in the case of FB reading, processing relating to the subsequent document is deleted.

  (6) In each of the above embodiments, the CPU 20 may execute processing by the measurement unit and the image processing unit. Moreover, although CPU20 was shown as an example of a reading control part and a change part, it is not restricted to this. For example, the reading control unit and the changing unit may be configured by a plurality of circuits including an ASIC, or may be configured by a CPU and other individual circuits.

  (7) In the above embodiment, the transmission process is executed in parallel with the reading process. However, the present invention is not limited to this. For example, the CPU 20 may use Ping in order to acquire the transmission speed S calculated by the communication speed measurement unit 26 (step S135). In this case, the CPU 20 does not need to perform transmission processing and reading processing in parallel.

  (8) In the above embodiment, in step S145 of the reading process, the sub-scanning reading resolution is changed from “100 dpi” to “300 dpi”, but the present invention is not limited to this. For example, the main scanning reading resolution may be changed from “100 dpi” to “300 dpi” by causing the light emitting elements provided in the CIS to emit light three times as many times. In this case, as a method of changing the main scanning reading resolution from “300 dpi” to “100 dpi” in step S155, an average value of the three pixels is obtained with three pixels as one unit in the main scanning direction of the read image data. It is preferable to perform image processing for conversion into one pixel.

  It should be noted that the change in the main scanning reading resolution from “100 dpi” to “300 dpi” and the change in the sub-scanning reading resolution from “100 dpi” to “300 dpi” may be performed in combination. The time required for reading can be further increased, and it can be expected that the time from when the image of the original is read until the image data is stored in the communication buffer 22B is further increased.

DESCRIPTION OF SYMBOLS 1 ... MFP, 3 ... Image reading device, 5 ... Document, 10 ... Image forming part, 20 ... CPU, 22 ... RAM, 22B ... Communication buffer, 24 ... Network I / F, 26 ... Image form processing part, 27 ... Image shape processing unit, 30 ... reading unit, 34 ... carriage, 40 ... ADF, 44 ... conveying roller, 44A ... feed roller, 47 ... rear sensor, 49 ... front sensor, 60 ... reading drive unit

Claims (7)

A reading unit that reads an image of a document and generates image data;
A setting accepting unit that accepts a reading setting when the reading unit reads an image of a document;
A storage unit for storing the image data;
A transmission unit for transmitting the image data stored in the storage unit to an external device;
A measurement unit for measuring a transmission speed when the image data is transmitted to the external device by the transmission unit;
When the transmission speed measured by the measurement unit is less than a predetermined transmission rate, the reading setting received by the setting receiving unit is the original reading time of the reading unit by the reading setting received by the setting receiving unit. A change unit that performs a change process for changing the reading setting to be longer than the original reading time;
When the reading setting received by the setting receiving unit causes the reading unit to read the image of the document and generate the image data, and the reading unit is changed by the changing unit, the changed reading is performed. A reading control unit that causes the reading unit to generate image data according to settings;
An image processing unit that performs image processing so that the image data generated according to the changed reading setting matches the image data obtained by the reading setting received by the setting receiving unit;
The image reading apparatus, wherein the reading control unit stores the image data processed by the image processing unit in the storage unit. The image reading apparatus according to claim 1,
In the storage unit, image data for each part of the image generated in the reading unit is sequentially stored,
The transmission unit is an image reading device that sequentially transmits the image data for each part stored in the storage unit to an external device when the reading unit reads an image of a document. The image reading apparatus according to claim 1 or 2,
The reading settings include resolution settings,
In the change process, the change unit changes the resolution to a resolution higher than the resolution received by the setting reception unit,
In the image processing, the image processing unit converts image data obtained by the resolution changed by the changing unit into image data having a resolution received by the setting receiving unit. The image reading apparatus according to claim 1 or 2,
The reading setting includes a setting for single-color reading or multi-color reading,
The change unit changes the reading setting to multi-color reading when the setting reception unit accepts single-color reading in the changing process,
The image processing unit, in the image processing, converts image data obtained by the multi-color reading into image data obtained by the single-color reading. The image reading apparatus according to any one of claims 1 to 3,
The reading settings include settings for resolution and single-color reading or multi-color reading,
The changing unit changes the reading setting to multi-color reading when there is no resolution higher than the resolution received by the setting receiving unit and the setting receiving unit receives single color reading in the changing process,
The image processing unit, in the image processing, converts image data obtained by the multi-color reading into image data obtained by the single-color reading. In the image reading device according to any one of claims 1 to 5,
A designation receiving unit that accepts designation of a reading range that is a range in which the reading unit reads a document;
A transport section for transporting a document;
A leading edge sensor for detecting the leading edge of the document conveyed by the conveying unit;
The changing unit is
Starting the change process for the reading range based on detection of the leading edge of the document by the leading edge sensor;
An image reading apparatus that, outside the reading range, returns the changed reading setting to the reading setting received by the setting receiving unit. In the image reading device according to any one of claims 1 to 5,
A transport section for transporting a document;
A document sensor that detects a subsequent document following the document;
The changing unit is configured to read the changed document during a conveyance period in which the subsequent document is conveyed by the conveyance unit until the reading of the subsequent document is started when the subsequent document is detected by the document sensor. An image reading apparatus that returns the setting to the reading setting accepted by the setting receiving unit.

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