JP6323002B2 - Image reading device - Google Patents

Description

  The present invention relates to a technique for reading an original and generating image data.

  Conventionally, in order to reduce noise generated when a document is read, in the silent mode, the raster image is displayed at the same resolution as the normal mode by reading the document while moving the main scanning range in the sub-scanning direction at a lower speed than the normal mode. An image reading apparatus that generates data is known (see, for example, Patent Document 1).

JP 2005-94688 A

  However, according to the above-described conventional technique, when reading an original in the normal mode, the normal mode is continued until the reading of the original is finished, and when reading the original in the silent mode, the silent mode is continued until the reading of the original is finished. End up.

  In this specification, normal reading processing for reading one or more originals at a first speed as in the normal mode, and reading one or more originals at a second speed lower than the first speed as in the silent mode. Disclosed is a technique for suppressing inconvenience caused by continuing one reading process of at least one reading process among the low-speed reading processes until one or more originals are read.

  An image reading apparatus disclosed in the present specification includes a reading unit, a conveyance unit, and a control unit, and the control unit uses the conveyance unit to move the document and the reading unit at a first speed. A normal reading process of causing the reading unit to read one or more originals and generating image data of a set resolution, and a second speed lower than the first speed using the transport unit; A low-speed reading process for causing the reading unit to read one or more originals and generating image data of the set resolution; and a reception process for receiving a speed change request; Regarding at least one of the normal reading process and the low-speed reading process, the speed change request is made by the receiving process while the reading unit is reading one or more documents by the one reading process. When only attached, it executes a switching process of switching on the way the reading of the one or more document to the other reading process.

  According to the image reading apparatus, by making a speed change request while reading one or more documents, it is possible to switch to the other reading process while reading one or more documents. Accordingly, it is possible to suppress inconvenience due to the one reading process being continued until reading of one or more originals is completed.

  Further, the control unit executes a preparation process corresponding to a reading resolution in a main scanning direction before executing the normal reading process and before executing the low-speed reading process, and performs the normal reading process and the low-speed reading process. When the reading unit reads the one or more originals at the same reading resolution in the main scanning direction in the reading process, and the switching process is switched to the other reading process, the other process is not performed. A reading process may be executed.

  According to the image reading apparatus, the preparation process is not executed when the reading process is switched to the other reading process in the middle of reading one or more originals by the one reading process. Compared to the case, it is possible to shorten the time from when the speed change request is received until the other reading process is started.

  Further, in the switching process, the control unit may switch to the other reading process in the middle of reading the document currently being read.

  According to the image reading apparatus, since the other reading process is switched during the reading of the document currently being read, the other reading process is performed at an earlier time point than when the reading process is switched to the other reading process after the reading of the currently reading document is completed. Can be switched to the reading process.

  The transport unit transports the documents placed on the document tray one by one, and the control unit reads the next document after the reading of the document currently being read is completed in the switching process. You may switch to said other reading process before starting.

  If the reading process is switched in the middle of reading the document that is currently being read, the image quality of the image represented by the image data generated by reading the document may change during the reading. According to the image reading apparatus, after the reading of the currently read original is completed, the reading process is switched to the other reading process before starting the reading of the next original, so that the image data generated by reading the current reading original is It can suppress that the image quality of the image to represent changes in the middle.

  In the normal reading process, the control unit causes the reading unit to read the one or more documents at a line cycle in which the reading resolution in the sub-scanning direction becomes the set resolution, and in the low-speed reading process, The reading unit may cause the reading unit to read the one or more originals at a line period that is longer than the line period in the normal reading process and whose reading resolution in the sub-scanning direction is the set resolution.

  According to the image reading apparatus, in the low-speed reading process, one or more documents are read at a line period that is a line period longer than the line period in the normal reading process and that has a resolution set in the sub-scanning direction. Even if the original and the reading unit are relatively moved at a second speed lower than the first speed, the resolution in the sub-scanning direction of the generated image data is the same as the set resolution. For this reason, in the low-speed reading process, it is not necessary to perform image processing for reducing the resolution in the sub-scanning direction of the image data to the set resolution after the image data is generated. Thereby, image data can be generated efficiently.

  In the normal reading process, the control unit causes the reading unit to read the one or more documents at a line cycle in which the reading resolution in the sub-scanning direction becomes the set resolution, and in the low-speed reading process, By causing the reading unit to read the one or more originals at the same line cycle as the line cycle in the normal reading process, the image data having a higher resolution in the sub-scanning direction than the set resolution is generated. Image processing for reducing the resolution in the sub-scanning direction to the set resolution may be executed.

  If the line cycle is different between the normal reading process and the low-speed reading process, the process at the time of switching becomes complicated. According to the image reading apparatus, since the line cycle is made the same in the normal reading process and the low-speed reading process, the process at the time of switching can be simplified. However, since the low-speed reading process is slower than the normal reading process, if the line cycle is the same, the resolution in the sub-scanning direction of the image data becomes higher than the set resolution in the low-speed reading process. According to the image reading apparatus, since the image processing for reducing the resolution in the sub-scanning direction of the generated image data to the set resolution is performed in the low-speed reading processing, the processing at the time of switching is simplified and the low-speed reading processing is performed. The resolution in the sub-scanning direction of the image data can be made the same as the set resolution.

  In addition, the image reading apparatus includes a reference member, the reading unit includes a light source, and the preparation process causes the reading unit to read the reference member in a state where the light source is turned on. It may include a process of adjusting.

  In order to adjust the light quantity of the light source, it takes time because the reading unit must read the reference member. For this reason, if the preparation process is not executed when switching to the other reading process in the middle of reading one or more originals by one reading process, the period from when the speed change request is accepted until the other reading process starts. You can save time.

  The image reading apparatus includes a reference member, the reading unit includes a light source, and the preparation process is performed for shading correction by causing the reading unit to read the reference member with the light source turned on. A process of generating a reference value of

  In order to generate a reference value for shading correction, it takes time because the reading unit must read the reference member. For this reason, if the preparation process is not executed when switching to the other reading process in the middle of reading one or more originals by one reading process, the period from when the speed change request is accepted until the other reading process starts. You can save time.

  The technique disclosed in this specification can be realized in various modes such as an image reading method, an image reading system, an image reading program, and a recording medium on which the image reading program is recorded.

  According to the image reading apparatus, at least one of a normal reading process for reading one or more originals at a first speed and a low-speed reading process for reading one or more originals at a second speed lower than the first speed. In this reading process, it is possible to suppress inconvenience due to the one reading process being continued until reading of one or more originals is completed.

FIG. 3 is a cross-sectional view of the image reading apparatus according to the first embodiment. FIG. 3 is a block diagram showing a simplified electrical configuration of the image reading apparatus. The schematic diagram of an operation screen. The wave form diagram for demonstrating normal mode. The waveform diagram for demonstrating silent mode. The flowchart of the reading control process in the case of 300 dpi and silent mode. The flowchart of a switching process. 10 is a flowchart of a reading control process in a 300 dpi, silent mode according to the second embodiment.

<Embodiment 1>
The first embodiment will be described with reference to FIGS.
(1) Configuration of Image Reading Apparatus The configuration of the image reading apparatus 1 according to the first embodiment will be described with reference to FIG. The image reading apparatus 1 is a so-called CIS (Contact Image Sensor) type image reading apparatus.

  A housing 10 of the image reading apparatus 1 is formed in a generally box shape, and a first platen glass 11 and a second platen glass 12 are provided on the top. The document cover 13 is connected to the housing 10 so as to be rotatable between a closed posture that covers the first platen glass 11 and the second platen glass 12 and an open posture that opens the first platen glass 11 and the second platen glass 12. . The document cover 13 is provided with an ADF (Auto Document Feeder) 14, a document tray 15, a paper discharge tray 16, and the like.

  The ADF 14 includes a paper feed roller 17, a plurality of roller pairs 18 a, 18 b, 18 c, an ADF motor 42 (see FIG. 2) that drives these, a conveyance path 19, a document sensor 20, a rear sensor 21, and the like. The originals placed on the paper are conveyed one by one along the conveyance path 19. The document sensor 20 is a sensor that detects the presence or absence of a document on the document tray 15 and outputs an output signal corresponding to the presence or absence of the document. The rear sensor 21 is a sensor that detects the presence or absence of a document in the conveyance path 19 and outputs an output signal corresponding to the presence or absence of the document. The ADF 14 is an example of a transport unit.

  The reading unit 22 is a manuscript that is emitted from a light source 24 composed of a COMS image sensor 23 in which a plurality of light receiving elements are linearly arranged in the direction perpendicular to the paper surface (main scanning direction), light emitting diodes of RGB three colors, etc. An optical system 25 that forms an image of the reflected light on each light receiving element of the CMOS image sensor 23, a carriage 26 on which these are mounted, and the like. In the following description, the CMOS image sensor 23 is simply referred to as the image sensor 23.

  An FB (Flat Bed) transport unit 27 includes a driving roller 28, a driven roller 29, a belt 30 driven by the driving roller 28 and the driven roller 29, an FB motor 41 (see FIG. 2) that rotationally drives the driving roller 28, and the like. And the reading unit 22 is conveyed in the sub-scanning direction (A direction in the drawing) parallel to the first platen glass 11. The FB transport unit 27 is an example of a transport unit.

  The white reference plate 31 is a white plate-like member having a substantially uniform light reflectance. The white reference plate 31 is provided at a position between the first platen glass 11 and the second platen glass 12 inside the housing 10 so as to extend in a direction perpendicular to the paper surface. The white reference plate 31 is used for adjusting the light amount of the light source 24 and for generating a white reference value for shading correction. The white reference plate 31 is an example of a reference member.

  When reading the document placed on the first platen glass 11, the image reading apparatus 1 reads the document line by line while transporting the reading unit 22 in the sub-scanning direction by the FB transport unit 27. On the other hand, when reading one or more documents by the ADF 14, the image reading apparatus 1 uses the FB conveyance unit 27 to convey the reading unit 22 to an ADF reading position that is a position directly below the second platen glass 12. A document passing over the second platen glass 12 is read line by line by the image sensor 23.

(2) Electrical Configuration of Image Reading Device As shown in FIG. 2, the image reading device 1 includes a control unit 40, an FB motor 41, an ADF motor 42, a reading unit 22, an AFE (Analog Front End) 43, an operation unit 44, The document sensor 20 and the rear sensor 21 are provided.

  The control unit 40 includes a CPU 40A, a ROM 40B, a RAM 40C, an ASIC 40D, and the like. The CPU 40A controls each unit of the image reading apparatus 1 by executing a control program stored in the ROM 40B. The ROM 40B stores a control program executed by the CPU 40A, various data, and the like. The RAM 40C is used as a main storage device for the CPU 40A to execute various processes.

  An FB motor 41, an ADF motor 42, a reading unit 22, an AFE 43, and the like are connected to the ASIC 40D. The ASIC 40D controls these under the control of the CPU 40A. Further, the ASIC 40D performs gamma correction, shading correction, and other various image processing on the pixel signal output from the AFE 43 to generate image data having three RGB RGB values for each pixel.

  The AFE 43 is a circuit that performs gain adjustment, A / D conversion, and the like of the analog signal (voltage) output from the image sensor 23 and outputs a pixel signal to the ASIC 40D.

  The operation unit 44 includes a display device such as a liquid crystal display and a touch panel that covers the display device. The user can perform various operations by pressing the operation buttons displayed on the display device from above the touch panel. Note that the operation unit 44 may be configured to accept various operations using physical operation buttons.

(3) Operation Screen Next, an operation screen 50 displayed on the operation unit 44 will be described with reference to FIG. When the user operates the operation unit 44 and selects the image reading function, the CPU 40A displays an operation screen 50 as shown in FIG.

  The resolution setting column 51 is a column for setting the resolution of image data to be generated. In the illustrated example, 300 dpi, 600 dpi, and 1200 dpi can be set. For example, when 300 dpi is set, image data with a resolution in the main scanning direction and a resolution in the sub-scanning direction of 300 dpi is generated.

  The reading mode selection column 52 is a column for selecting a reading mode. The reading mode includes a normal mode and a silent mode. These reading modes will be described later. The reading start button 53 is a button for the user to instruct reading of a document.

(4) Switching of Reading Mode and Reading Mode Next, switching of the reading mode and the reading mode will be described. Here, a case where a document is conveyed and read by the ADF 14 will be described as an example. When reading a document placed on the first platen glass 11, the first speed and the second speed described below are the speeds at which the FB transport unit 27 transports the carriage 26. .

  The normal mode is a reading mode in which an original is conveyed at a first speed set in advance and the reading unit 22 reads one or more originals to generate image data having the resolution set in the resolution setting field 51. It is. In the silent mode, the document is conveyed at a second speed lower than the first speed, and the reading unit 22 is caused to read one or more documents, and image data having the resolution set in the resolution setting column 51 is generated. It is a reading mode.

  In the normal mode, the speed at which the document is conveyed is higher than that in the silent mode, so that the time required for reading the document is shorter than in the silent mode. However, when the document is conveyed at a high speed, noise due to the rotation of the ADF motor 42 increases. In particular, when a document is read at a low resolution such as 300 dpi, noise is increased because the document is conveyed at a high speed.

  On the other hand, the quiet mode is slower in conveying the document than the normal mode, so that image data with the same resolution can be generated while reducing such noise. The silent mode is particularly effective when reading a document at a low resolution.

  With reference to FIGS. 4 and 5, the normal mode and the silent mode will be described more specifically. 4 and 5 show a case where the resolution set in the resolution setting column 51 is 300 dpi.

(4-1) Normal Mode First, the normal mode will be described with reference to FIG. In the normal mode, the CPU 40A sets one line cycle when reading the document to the reading unit 22, the reading resolution in the main scanning direction, and the document conveyance speed for 300 dpi.

  One line cycle is the time required to read one line. As shown in FIG. 4, in this embodiment, it is assumed that one line cycle for 300 dpi is 2587 clocks.

  The reading resolution in the main scanning direction is the resolution when the image sensor 23 reads a document. For example, when the original is read using all the light receiving elements except the invalid light receiving elements at both ends among the plurality of light receiving elements constituting the image sensor 23, the reading resolution in the main scanning direction becomes 1200 dpi. In this case, the CPU 40A sets the reading resolution in the main scanning direction to 300 dpi by setting the original to be read using only one light receiving element for every four consecutive light receiving elements. When the reading resolution in the main scanning direction is set to 300 dpi, as shown in FIG. 4, the charges accumulated in the light receiving element are sequentially converted into analog signals during the period of 0083 to 2584 clocks and output to the AFE 43.

  Here, in this embodiment, when the reading resolution in the main scanning direction is changed, the light source setting value is also changed accordingly. The light source set value is a value indicating a lighting period during which the light source 24 is turned on during one line period, and a value indicating a current value supplied to the light source 24. The lighting period is set by the timing for turning on the light source 24 and the timing for turning off the light source 24.

  As will be described in detail later, the CPU 40A finely adjusts the lighting period of the light source 24 and the current value supplied to the light source 24 by executing a preparation process described later after setting the light source setting value for 300 dpi. The example shown in FIG. 4 shows a case where the lighting period of the light source 24 is set to 0083 to 2585 clocks as a result of fine adjustment by the preparation process. The light source setting value may be only the lighting period of the light source 24. This is because if the lighting period of the light source 24 is determined, the current value is inevitably determined in order to keep the light quantity constant.

  The document transport speed is the speed at which the ADF 14 transports the document. The document transport speed is set by the number of motor drive pulses output per line cycle. As shown in FIG. 4, in the case of a 300 dpi transport speed, the number of motor drive pulses output per line cycle, that is, the number of motor drive pulses output per 2587 clocks is set to 2.

  The conveyance speed for 300 dpi is an example of the first speed. Further, the process in which the CPU 40A causes the reading unit 22 to read the original in the normal mode and generates image data with the set resolution is an example of the normal reading process.

(4-2) Silent Mode Next, the silent mode will be described with reference to FIG. In the silent mode, the CPU 40A sets the reading resolution in the main scanning direction for the resolution set in the resolution setting column 51 as in the normal mode. That is, the CPU 40A makes the reading resolution in the main scanning direction the same in the normal mode and the silent mode. The reason why the reading resolution in the main scanning direction is the same in the normal mode and the silent mode will be described in the explanation of the preparation process described later.

  On the other hand, the one-line cycle and the document conveyance speed are set for a resolution one step higher than the resolution set in the resolution setting field 51. The one-step larger resolution is 600 dpi when the set resolution is 300 dpi, 1200 dpi when the set resolution is 600 dpi, and 2400 dpi when the set resolution is 1200 dpi. is there.

  In the present embodiment, it is assumed that one line cycle for 600 dpi is 5174 clocks, which is twice as long as one line cycle for 300 dpi. For this reason, when the resolution set in the resolution setting column 51 is 300 dpi, one line cycle is set to 5174 clocks as shown in FIG. The reason for setting one line period to 5174 clocks will be described later.

  In the present embodiment, it is assumed that the number of motor drive pulses output per 5174 clocks is set to 2 when the conveyance speed for 600 dpi is set. Therefore, when the resolution set in the resolution setting column 51 is 300 dpi, the number of motor drive pulses output per 5174 clocks is set to 2 as shown in FIG.

  As described above, when the conveyance speed for 300 dpi is set, the number of motor drive pulses output per 2587 clock is 2, so the conveyance speed for 600 dpi is ½ of the conveyance speed for 300 dpi. The reason for reducing the conveyance speed is to suppress noise as described above.

  Next, the reason why one line cycle is set to 5174 clocks in the silent mode will be described. The reason for setting one line cycle to 5174 clocks is to make the reading resolution in the sub-scanning direction the same as in the normal mode. As described above, in the silent mode, the document conveyance speed is ½ that in the normal mode. Therefore, if the one-line cycle remains at the same 2587 clock as in the normal mode, the reading resolution in the sub-scanning direction is twice that in the normal mode. Become.

  On the other hand, if one line cycle is 5174 clocks, which is twice that of the normal mode, the original is read in the first half of the period of 0000 to 2587 clocks, and the latter half of the period of 2588 to 5174 clocks. Is only conveyed and no reading is performed. For this reason, the reading resolution in the sub-scanning direction can be made the same as in the normal mode even if the conveyance speed is halved.

  The conveyance speed for 600 dpi is an example of a second speed that is lower than the first speed. In addition, the process in which the control unit 40 causes the reading unit 22 to read the original in the silent mode and generates image data with the set resolution is an example of a low-speed reading process.

(4-3) Switching of Reading Mode By the way, the silent mode requires a long time for reading a document because the document conveyance speed is slower than that in the normal mode. For this reason, it may be considered that the user feels that reading of the original document is not finished while the reading unit 22 is reading one or more original documents, and regrets that the silent mode has been set. Or, conversely, since the normal mode is louder than the quiet mode, the user feels that the noise is loud while the reading unit 22 is reading one or more documents, and regrets that the normal mode has been set. It is also possible.

  For this reason, when reading the document in the normal mode, the normal mode is continued until the reading of the document is finished. When the document is read in the silent mode, if the silent mode is continued until the reading of the document is finished, the user regrets on the way. It is inconvenient for the user.

  Therefore, in the image reading apparatus 1, the user can change the reading mode while the reading unit 22 is reading one or more documents. The reading mode can be changed by selecting the other reading mode on the operation screen 50 described above while the reading unit 22 is reading one or more originals in one reading mode. When the reading mode is changed while one or more originals are being read, the CPU 40A switches to the other reading mode while reading the one or more originals, and the reading unit 22 receives the remaining originals. Let me read.

  The process in which the CPU 40A accepts the change of the reading mode on the operation screen 50 is an example of the accepting process. Changing the reading mode is an example of a speed change request.

(5) Preparation Process When the user presses the reading start button 53 on the operation screen 50 described above, the CPU 40A executes a preparation process before the reading unit 22 starts reading the document. The preparation process includes a light amount adjustment process and a white reference value generation process.

  In the light amount adjustment process, the white reference plate 31 is read by the reading unit 22 in a state where the light source 24 is turned on with the light source setting value described above, and the lighting period of the light source 24 and the light source 24 are set based on the pixel signal output from the AFE 43. This is a process for finely adjusting the supplied current value.

The white reference value generation process is a process of causing the reading unit 22 to read the white reference plate 31 with the light source 24 turned on, and generating a white reference value for shading correction based on the pixel signal output from the AFE 43. is there.
In addition, the preparation process may include a process of generating a black reference value for shading correction.

  Incidentally, as described above, in the present embodiment, the reading resolution in the main scanning direction is made the same in the normal mode and the silent mode. In this embodiment, when the reading resolution in the main scanning direction is changed, the light source setting value is also changed accordingly. Therefore, if the reading resolution in the main scanning direction is different between the normal mode and the silent mode, the reading mode is changed. This is because when the switching is performed, the lighting period of the light source 24 and the current value must be finely adjusted before the reading unit 22 starts to read the document in the switched reading mode. In addition, since the sensitivity variation of the light receiving element also changes depending on the brightness of the light source 24, the white reference value must be generated again when the current value supplied to the light source 24 changes.

  That is, if the reading resolution in the main scanning direction is different between the normal mode and the silent mode, when the reading mode is switched, the preparation process is executed before the reading unit 22 starts reading the document in the switching reading mode after switching. I have to fix it. When the preparation process is executed again, the reading unit 22 is moved from the ADF reading position directly below the white reference plate 31, and the reading unit 22 reads the white reference plate 31 to perform the light amount adjustment process and the white reference value generation process. Since it takes time, time to return the reading unit 22 from the position immediately below the white reference plate 31 to the ADF reading position, etc., switching takes time.

  On the other hand, if the reading resolution in the main scanning direction is the same in the normal mode and the silent mode, the preparation process executed when the reading start button 53 is pressed is transferred to the reading unit 22 in the changed reading mode. This can be regarded as a preparatory process executed before reading is started. This is because, since the light source setting values are the same, the result of the preparation process should be the same even when the original is read by the other reading process from the beginning. For this reason, if the reading resolution in the main scanning direction is the same, it is possible to eliminate the preparation process before the reading unit 22 starts reading the document in the reading mode after switching.

(6) Reading Control Processing Next, reading control processing executed by the CPU 40A will be described. This process is started when the user presses the reading start button 53 on the operation screen 50.

(6-1) 300 dpi, Silent Mode First, the case where 300 dpi is set in the resolution setting field 51 and the silent mode is selected in the reading mode selection field 52 will be described with reference to FIG. To do. Here, a case where one or more originals are conveyed and read by the ADF 14 will be described as an example. Here, when the reading unit 22 is changed to the normal mode while one or more originals are being read, after the reading of the currently read original is completed, the reading of the next original is started. An example of switching to the normal mode will be described.

In S101, the CPU 40A sets one line cycle for 600 dpi. That is, the CPU 40A sets one line cycle to 5174 clocks.
In S102, the CPU 40A sets the reading resolution in the main scanning direction and the light source setting value for 300 dpi.

  In S103, the CPU 40A causes the FB transport unit 27 to transport the reading unit 22 directly below the white reference plate 31, and executes the above-described preparation process.

In S104, the CPU 40A causes the FB conveyance unit 27 to convey the reading unit 22 to the ADF reading position.
In S105, the CPU 40A sets the document transport speed for 600 dpi. That is, the CPU 40A sets the number of motor drive pulses output per 5174 clocks to 2.

In S106, the CPU 40A causes the ADF 14 to start conveying the document.
In S107, the CPU 40A detects the leading edge of the document. Specifically, the CPU 40A determines whether or not the rear sensor 21 is on. If the rear sensor 21 is on (S107: Yes), the CPU 40A proceeds to S108 as detecting the leading edge of the document, and if it is off (S107: No). Repeats the determination of S107, assuming that the leading edge of the document is not detected.

  In S <b> 108, the CPU 40 </ b> A waits until the leading edge of the document reaches just before the position where the reading unit 22 reads the document, and then causes the reading unit 22 to start reading the document. Whether or not the leading edge of the document has reached just before the position where it is read by the reading unit 22 can be determined by, for example, the elapsed time from when the rear sensor 21 changes from off to on.

  In S109, the CPU 40A detects the trailing edge of the document. Specifically, the CPU 40A determines whether or not the rear sensor 21 is off. If it is off (S109: Yes), the CPU 40A proceeds to S110 because it detects the trailing edge of the document, and if it is on (S109: No). ) Repeats the determination in S109 because the trailing edge of the document is not detected.

  In S <b> 110, the CPU 40 </ b> A waits until the trailing edge of the document passes the position read by the reading unit 22 and then causes the reading unit 22 to stop reading the document. Whether or not the trailing edge of the document has passed the position read by the reading unit 22 can be determined, for example, by the elapsed time from when the rear sensor 21 changes from on to off.

  In S111, the CPU 40A determines whether there is a next document. Specifically, CPU 40A determines whether or not document sensor 20 is on. If it is on, CPU 40A determines that there is a next document. If it is off, CPU 40A determines that there is no next document. If there is no next original (S111: No), the CPU 40A proceeds to S112, and if present (S111: Yes), the CPU 40A proceeds to S113. Note that the rear sensor 21 may be used to determine whether there is a next document.

In S112, the CPU 40A causes the ADF 14 to stop the conveyance of the document.
In S113, the CPU 40A determines whether or not the reading mode has been changed. If it has been changed (S113: Yes), the process proceeds to S114, and if it has not been changed (S113: No), the process returns to S107.

  In S114, the CPU 40A executes a switching process for switching the reading mode. The switching process will be described later. After executing the switching process, the CPU 40A returns to S107. For this reason, the remaining originals are read in the changed reading mode.

(6-2) Switching Process Next, the switching process executed in S114 will be described with reference to FIG.
In S201, the CPU 40A causes the ADF 14 to interrupt the conveyance of the document.
In S202, the CPU 40A sets one line cycle for 300 dpi. That is, the CPU 40A sets one line cycle to 2587 clocks.

In S203, the CPU 40A sets the document transport speed for 300 dpi. That is, the CPU 40A sets the number of motor drive pulses output per 2587 clocks to 2.
In S204, the CPU 40A causes the ADF 14 to resume the conveyance of the document.

  With the above processing, the reading resolution in the main scanning direction, the light source setting value, the document conveyance speed, and the one line cycle are all for 300 dpi. This switches to the normal mode.

(6-3) 300 dpi, Normal Mode Next, a case where 300 dpi is set in the resolution setting field 51 and the normal mode is selected in the reading mode selection field 52 will be described as an example. Here, the difference from the 300 dpi, silent mode will be described with reference to FIGS. 6 and 7 described above.

  In the case of 300 dpi and normal mode, the CPU 40A executes processing for setting one line cycle for 300 dpi instead of S101 shown in FIG. 6, and processing for setting the document transport speed for 300 dpi instead of S105. Run.

Further, the CPU 40A executes a process of setting one line cycle for 600 dpi instead of S202 shown in FIG. 7, and executes a process of setting the document conveyance speed for 600 dpi instead of S203.
The processing in the 300 dpi, normal mode is substantially the same as the processing in the 300 dpi, silent mode in other respects.

(7) Effects of the Embodiment According to the image reading apparatus 1 according to the first embodiment described above, the other reading mode is in the middle of reading one or more originals by changing the reading mode in the middle of reading one or more originals. You can switch to Accordingly, it is possible to suppress inconvenience due to the one reading mode being continued until reading of one or more originals is completed.

  Further, according to the image reading apparatus 1, when the normal mode and the silent mode allow the reading unit 22 to read one or more documents with the same reading resolution in the main scanning direction, and the switching process switches to the other reading mode, the preparation process Since the original is read in the other reading mode without performing the above, the reading unit 22 in the other reading mode after accepting the change in the reading mode also when switching to the other reading mode, compared to the case where the preparation process is executed. It is possible to shorten the time until the document reading is started.

  Further, according to the image reading apparatus 1, when the reading mode is changed while the originals placed on the original tray 15 are conveyed one by one by the ADF 14 and the reading unit 22 is reading one or more originals. Is switched to the other reading mode after the reading of the currently read original is completed and before the reading of the next original is started. If the reading mode is switched in the middle of reading a document that is currently being read, the image quality of the image represented by the image data generated by reading the document may change during the reading. According to the image reading apparatus 1, after the reading of the currently read original is completed, the reading mode is switched to the other reading mode before starting the reading of the next original. Therefore, the image data generated by reading the current original is read. It can suppress that the image quality of the image to represent changes in the middle.

  Further, according to the image reading apparatus 1, in the silent mode, the resolution (300 dpi) in which the reading resolution in the sub-scanning direction is set in one line cycle (5174 clocks) longer than one line cycle (2687 clocks) in the normal mode. Since one or more originals are read in one line cycle, the resolution in the sub-scanning direction of the generated image data is obtained even if the original and the reading unit 22 are relatively moved at a second speed lower than the first speed. And the set resolution is the same. For this reason, in the silent mode, it is not necessary to perform image processing for reducing the resolution in the sub-scanning direction of the image data to the set resolution after the image data is generated. Thereby, image data can be generated efficiently.

  Further, according to the image reading apparatus 1, the preparation process includes a process of adjusting the light amount of the light source 24 by causing the reading unit 22 to read the white reference plate 31 with the light source 24 turned on. In order to adjust the light quantity of the light source, it takes time because the reading unit 22 must read the white reference plate 31. For this reason, if the preparation process is not executed when switching to the other reading mode in the middle of reading one or more originals in one reading mode, the reading unit 22 in the other reading mode after accepting the change of the reading mode. It is possible to shorten the time until the document reading is started.

  Further, according to the image reading apparatus 1, the preparation process includes a process of generating a white reference value for shading correction by causing the reading unit 22 to read the white reference plate 31 with the light source 24 turned on. In order to generate the white reference value, it takes time because the reading unit 22 has to read the white reference plate 31. For this reason, if the preparation process is not executed when switching to the other reading mode in the middle of reading one or more originals in one reading mode, the reading unit 22 in the other reading mode after accepting the change of the reading mode. It is possible to shorten the time until the document reading is started.

<Embodiment 2>
Next, Embodiment 2 will be described with reference to FIG.
In the above-described first embodiment, when the reading mode is changed while the reading unit 22 is reading one or more originals, after the reading of the currently read original is completed, the reading of the next original is not started. The case of switching to the other reading mode has been described as an example. On the other hand, in the second embodiment, the reading mode is switched to the other reading mode in the middle of reading the document currently being read.

A reading control process according to the second embodiment will be described with reference to FIG. Since S101 to S106 are the same processes as those in the first embodiment, description thereof will be omitted.
In S301, the CPU 40A detects the leading edge of the document. Specifically, the CPU 40A determines whether or not the rear sensor 21 is on. If the rear sensor 21 is on (S301: Yes), the CPU 40A proceeds to S302 because it detects the leading edge of the document, and if it is off (S301: No). Repeats the determination in S301, assuming that the leading edge of the document has not been detected.

In S302, the CPU 40A causes the reading unit 22 to start reading a document.
In S303, the CPU 40A determines whether or not the reading mode has been changed. If it has been changed (S303: Yes), the process proceeds to S114, and if it has not been changed (S303: No), the process proceeds to S304.

  In S304, the CPU 40A detects the trailing edge of the document. Specifically, the CPU 40A determines whether or not the rear sensor 21 is off. If the rear sensor 21 is off (S304: Yes), the CPU 40A proceeds to S305 because the trailing edge of the document is detected, and if it is on (S304: No). ) Repeats the determination in S304, assuming that the trailing edge of the document is not detected.

In S305, the CPU 40A causes the reading unit 22 to stop reading the document.
In S306, the CPU 40A determines whether or not there is a next document. If there is (S306: Yes), the process returns to S301. If not (S306: No), the process proceeds to S307.
In step S307, the CPU 40A stops the conveyance of the document by the ADF 14.

  According to the image reading apparatus 1 according to the second embodiment described above, when the reading mode is changed while the reading unit 22 is reading one or more originals (S303: Yes), the currently read original is read. Since the reading mode is switched to the other reading mode in the middle of reading (S114), it is possible to switch to the other reading mode at an earlier time point compared to the case of switching to the other reading mode after the reading of the document currently being read is completed.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and the drawings, and for example, the following embodiments are also included in the technical scope.

  (1) In the first embodiment, the case where a document conveyed by the ADF 14 is read has been described as an example. On the other hand, when reading a document placed on the first platen glass 11, the reading mode may be switched during reading. In this case, the reading mode is switched during the reading of the document currently being read.

  (2) In the above embodiment, the case where both the switching from the silent mode to the normal mode and the switching from the normal mode to the silent mode are possible has been described as an example. On the other hand, only one of them may be made possible.

  (3) In the above embodiment, the case where the reading unit 22 reads the document with the same reading resolution in the main scanning direction in the normal mode and the silent mode has been described as an example. On the other hand, the document may be read by the reading unit 22 at different reading resolutions in the main scanning direction between the normal mode and the silent mode. For example, when the set resolution is 300 dpi, the reading resolution in the main scanning direction may be set to 300 dpi in the normal mode, and the reading resolution in the main scanning direction may be set to 600 dpi in the silent mode. However, in such a case, the resolution in the main scanning direction of the image data generated in the silent mode is 600 dpi. In that case, the resolution in the main scanning direction of the image data may be reduced to 300 dpi by image processing.

  (4) In the above-described embodiment, the case where one line cycle is set to one line cycle for resolution larger by one step than the set resolution has been described as an example in the silent mode. On the other hand, even in the silent mode, one line cycle may be set to a resolution one line cycle. If the period of one line is different between the normal mode and the silent mode, the process at the time of switching becomes complicated. Even in the silent mode, if one line cycle is set to one resolution cycle, the processing at the time of switching can be simplified.

  However, in such a case, for example, when the set resolution is 300 dpi, the resolution in the sub-main scanning direction of the image data generated in the silent mode is 600 dpi. In that case, the resolution in the sub-scanning direction of the image data may be reduced to 300 dpi by image processing. This makes it possible to make the resolution in the sub-scanning direction of the image data the same as the set resolution in the silent mode while simplifying the process at the time of switching.

  (5) In the above-described embodiment, the image reading apparatus 1 that reads only one side of the document has been described as an example. On the other hand, the image reading apparatus may be capable of reading both sides of a document. As a double-sided reading method of an image reading device, a switchback method, a double CIS method, or the like is known.

  In the switchback method, a document is transported by the ADF 14 and one side of the document is read by the reading unit 22, and then the document is switched back and sent back to the transport path 19 with the front and back reversed. This is a method for causing the reading unit 22 to read this surface. In the case of the switchback method, when the reading mode is changed during the reading of the document, the reading mode may be switched during the reading of the currently reading document, or the currently reading surface is the one surface described above. In some cases, after the reading of the one surface is completed, the reading mode may be switched before the reading of the other surface is started.

  The double CIS system is a system in which a first reading unit 22 that reads one side of a document and a second reading unit 22 that reads the other side of the document are provided to simultaneously read both sides of the document. In the double CIS method, when the reading mode is switched, the reading mode is simultaneously switched for one side and the other side.

  (6) In the above embodiment, the case where the light source setting values are the same in the normal mode and the silent mode has been described as an example. On the other hand, in the silent mode, for example, the lighting period of the light source 24 may be twice that of the normal mode, and the current value supplied to the light source 24 may be ½ that of the normal mode. In this case, however, it is assumed that the preparation process is executed before the reading unit 22 reads the original in the read mode after switching.

  (7) In the above embodiment, the case where the change of the reading mode is received by the operation unit 44 of the image reading apparatus 1 has been described as an example. On the other hand, the reading mode may be changed from a computer that is communicably connected to the image reading apparatus 1.

  (8) In the above embodiment, the case where each process is executed by the CPU 40A has been described as an example. On the other hand, some of these processes may be executed by the ASIC 40D. Further, the control unit 40 may not include the ASIC 40D. In addition, the control unit 40 may include a plurality of CPUs, and the above-described processing may be shared and executed by the plurality of CPUs.

DESCRIPTION OF SYMBOLS 1 ... Image reading device, 15 ... Document tray, 22 ... Reading part, 24 ... Light source, 27 ... FB conveyance part, 31 ... White reference board, 40 ... Control part 40A ... CPU, 40B ... ROM, 40C ... RAM, 40D ... ASIC, 41 ... FB motor, 42 ... ADF motor, 44 ... operation unit, 50 ... Operation screen

Claims (6)

A reading unit;
A transport section;
A control unit;
With
The controller is
A normal reading process to generate image data and a document with the reading unit at a first speed to read the one or more document to the reading unit is relatively moved with the transport section,
Slow reading process is read by one or more of the document to the reading portion by relatively moving said reading unit and the original at a second speed slower than said first speed to generate image data by using the transport unit When,
A reception process for accepting a speed change request;
When receiving the speed change request by the receiving process in the middle of it to read the one or more document thus the reading unit to the treatment before Symbol slow reading, the low-speed reading processing in the middle reading of the document currently being read interrupted, and switching process that resumes the reading switches from the middle reading of the document currently being read to the normal reading process,
The execution,
When the control unit switches from the low-speed reading process to the normal reading process in the switching process, the normal reading process generates image data with the same resolution as that set by the low-speed reading process. apparatus. The image reading apparatus according to claim 1,
The controller is
Before executing the normal reading process and before executing the low-speed reading process, perform a preparation process according to the reading resolution in the main scanning direction,
When the normal reading process and the low-speed reading process cause the reading unit to read the one or more originals with the same reading resolution in the main scanning direction, and the switching process switches to the other reading process, the preparation process is performed. An image reading apparatus that executes the other reading process without executing it. The image reading apparatus according to claim 1 , wherein:
The controller is
In the normal reading process, the reading unit reads the one or more originals at a line cycle in which the reading resolution in the sub-scanning direction becomes the set resolution,
In the low-speed reading process, the reading unit is caused to read the one or more originals at a line period that is longer than the line period in the normal reading process and in which the reading resolution in the sub-scanning direction becomes the set resolution. Image reading device. The image reading apparatus according to claim 1 , wherein:
The controller is
In the normal reading process, the reading unit reads the one or more originals at a line cycle in which the reading resolution in the sub-scanning direction becomes the set resolution,
In the low-speed reading process, the reading unit is caused to read the one or more originals at the same line period as the line period in the normal reading process to generate image data whose resolution in the sub-scanning direction is higher than the set resolution. An image reading apparatus that executes image processing for reducing the resolution of the generated image data in the sub-scanning direction to the set resolution. The image reading apparatus according to claim 2,
A reference member,
The reading unit has a light source,
The preparation process includes an image reading apparatus including a process of adjusting the light amount of the light source by causing the reading unit to read the reference member with the light source turned on. The image reading apparatus according to claim 2,
A reference member,
The reading unit has a light source,
The preparatory process includes an image reading apparatus including a process of generating a reference value for shading correction by causing the reading unit to read the reference member with the light source turned on.

Images