JP2009111909A - Image reader, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of saving power, in an image reader configured to read an image of a document by using image sensors different in types installed on both front and back surface sides of the document to be transported, and an image forming device equipped with the image reader. <P>SOLUTION: When an image reading instruction is executed by a start button (YES in #1), a control part determines whether the image reader is in a situation where a reading operation should be executed in a high-speed mode or in a situation where the reading operation should be executed in a high-image-quality mode (#2). When it is determined that the image reader is in the situation where the reading operation should be executed in the high-image-quality mode (YES in #2), the control part executes the image reading operation (#4) after stopping power feed to a CIS by a power control circuit (#3), and executes the process of #4 by skipping the process of #3 when it is determined that the image reader is in the situation where the reading operation should be executed in the high-speed mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image reading apparatus capable of reading both sides of a document, and an image forming apparatus including the image reading apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a facsimile, the front and back surfaces of a document are automatically read by an image reading device provided with an automatic document feeder (ADF). In this document reading, a method is widely employed in which an image sensor reads an image on the front side of a document, then reverses the front and back sides of the document, and the image sensor reads the image on the back side of the document again.

  Further, as shown in Patent Document 1 below, by providing image sensors on both the front and back sides of the document in the document transport path from the document tray, the document can be transported once (one pass) without reversing the document. An image forming apparatus that employs a method of reading both sides of a document almost simultaneously is known. In an image forming apparatus that employs a method for reading both sides of a document almost simultaneously, one side of the document is read by a reduction optical system image sensor disposed on the apparatus body side, and the other side of the document is read by an installation. In many cases, the contact optical system image sensor disposed on the automatic document feeder side is used because of space and cost.

If the optical configuration of the image sensor that reads the front and back surfaces of the document is different as in the image forming apparatus disclosed in Patent Document 1, there is a difference in the image quality of the read image due to differences in the light source and lens array used for each. Arise. Further, the difference in image quality of the read image appears as a difference in image quality of images formed on the front and back surfaces of the recording paper. Therefore, in such an image forming apparatus, in order to make the image quality of the front and back surfaces of the recording paper the same, one original is reversed and conveyed twice to the same image sensor (reduction optical system image sensor). Double-sided reverse reading mode in which the front and back sides of the document are read by the image sensor, and double-sided scanning mode in which the front and back sides of the document are read almost simultaneously using two image sensors of the reduction optical system and the contact optical system in order to shorten the image reading time There may be two simultaneous reading modes.
JP 2004-15299 A

  By the way, in the above-described image reading apparatus having two modes of the double-sided reverse reading mode and the double-sided simultaneous reading mode, the power consumption is very large because a plurality of image sensors are mounted. Therefore, in recent years, power saving has been strongly demanded for this type of image forming apparatus.

  The present invention has been made to solve the above problem, and an image reading apparatus that reads an image of a document using different types of image sensors installed on both front and back sides of the conveyed document, and the image reading An object of the present invention is to propose a technique capable of saving power in an image forming apparatus including the apparatus.

  According to a first aspect of the present invention, there is provided a document feeding unit that feeds a document placed on a document placing unit and a reduction optical system image sensor, and the document conveyed by the document feeding unit. A first reading unit that reads an image on one side of the image using the reduction optical system image sensor, and a contact optical system image sensor, and the image on the other side of the document conveyed by the document feeding unit. A second reading unit that reads an image using the contact optical system image sensor, and after the reading of one side of the original by the first reading unit is finished, the other side of the original is read by the first reading unit. One side of the original is read by a reversing unit that is reversed and conveyed as a state to be read by the scanning unit, and one of the first reading unit and the second reading unit, and the reversing unit reads the surface of the original. After inversion The first reading unit reads one side of the original, and the second reading unit in a double-sided reverse reading mode in which the reading unit reads the other side of the original and a single original conveyance by the original feeding unit. Individually controls the power supply to the control unit that causes each unit to perform a document reading operation and the first and second reading units in any one of the double-sided simultaneous reading modes for reading the other side of the document. A power control circuit, and the power control circuit is configured to stop power supply to the unused one of the first and second reading units when the double-sided reverse reading mode is set. .

  According to the present invention, in the double-sided reversal reading mode, since one of the first and second reading units is not used, the power control circuit supplies the reading unit that is not used. By stopping the power supply, it is possible to save power compared to the case where power is supplied to the reading unit that is not used.

  According to a second aspect of the present invention, in the image reading device according to the first aspect, the power control circuit further comprises an upper limit value setting unit for performing input for setting an upper limit value of power consumption of the image reading device. When the power consumption input by the upper limit setting unit is smaller than a predetermined threshold value, the power supply to the unused one of the first and second reading units is stopped. .

  According to the present invention, when the user inputs using the input operation unit to set an upper limit value of power consumption smaller than a predetermined threshold value, the upper limit value of power consumption of the image forming apparatus is less than the threshold value. In order to be suppressed, power supply to the reading unit that is not used among the first and second reading units is stopped. As a result, compared to a configuration in which the upper limit value of power consumption of the image forming apparatus is not suppressed to be equal to or lower than the threshold value, power is supplied to the unused reading unit of the first and second reading units. Power saving can be achieved by the amount of stoppage.

  According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, a first input operation unit for selecting a reading mode from the double-sided reverse reading mode and the double-sided simultaneous reading mode; A detection unit that detects whether or not an image composed of the image data obtained by the reading operation of the first and second reading units is a color image, and a current result according to a detection result by the detection unit The suitability of the reading mode is determined, and when it is determined that the current reading mode is unsuitable, a determination unit that switches the reading mode to the other reading mode, and a determination mode that causes the determination unit to determine the suitability of the reading mode are set. A second input operation unit for performing input, wherein the power control circuit is a case where the double-sided reverse reading mode is selected by the first input operation unit, and the second input operation unit In Ri when the input is set to the determination mode is performed, and performs power supply to both of the first and the second reading section.

  According to the present invention, when an input for setting the determination mode is performed by the second input operation unit, an image composed of image data obtained by the reading operation of the first and second reading units is a color image. Whether the current reading mode is inappropriate or not is determined by the determination unit according to the detection result. When it is determined that the current reading mode is inappropriate, the reading mode is Can be switched to the reading mode.

  When such a determination mode is set when the double-side reverse reading mode is selected by the first input operation unit, exceptionally power is supplied to both the first and second reading units. Supply is performed by the power control circuit. As a result, since power is supplied to both the first and second reading units, the detection process by the detection unit can be reliably performed.

  According to a fourth aspect of the present invention, there is provided the image reading apparatus according to any one of the first to third aspects, and an image forming unit that forms an image on a recording sheet based on image data obtained by the reading operation of the reading unit. An image forming apparatus.

  According to this invention, there exists an effect | action obtained by the invention in any one of Claim 1 thru | or 3.

  According to the present invention, in an image reading apparatus that reads an image of a document using different types of image sensors installed on both front and back sides of the conveyed document, and an image forming apparatus including the image reading apparatus, power saving is achieved. Can be realized.

  Embodiments of an image reading apparatus and an image forming apparatus according to the present invention will be described below with reference to the drawings. In the following embodiment, an example in which the image reading apparatus and the image forming apparatus according to the present invention are integrated into a multifunction machine having functions such as a color copy, a scanner, a facsimile, and a printer will be described.

  FIG. 1 is a longitudinal sectional view schematically showing an internal configuration of a multifunction machine 1 as an embodiment of an image reading apparatus and an image forming apparatus according to the present invention. The multifunction device 1 is roughly composed of an image reading device 2 and a device body 3. The image reading apparatus 2 includes a document feeding unit 21, a scanner unit 22, a CIS 231, an operation unit 5, and a reversing mechanism and control unit 61 (see FIG. 3) described later. The document feeder 21 includes an ADF (Automatic Document Feeder), and includes a document tray 211, a pickup roller 212, a transport drum 213, a paper discharge roller 214, and a paper discharge tray 215. A document to be read is placed on the document tray 211. Documents placed on the document tray 211 are taken one by one by the pickup roller 212 and conveyed to the conveyance drum 213. The document that has passed through the transport drum 213 is discharged to a discharge tray 215 by a discharge roller 214.

  The scanner unit (first reading unit) 22 optically reads an image of a document and generates image data. The scanner unit 22 includes a platen glass 221, a light source 222, a first mirror 223, a second mirror 224, a third mirror 225, a first carriage 226, a second carriage 227, an imaging lens 228, and a CCD (Charge Coupled Device) 229. Prepare. In the scanner unit 22, a white fluorescent lamp such as a cold cathode fluorescent tube is used as the light source 222, and the first mirror 223, the second mirror 224, the third mirror 225, the first carriage 226, the second carriage 227, and the imaging. A lens 228 guides light from the document to the CCD 229. Since the scanner unit 22 uses a white fluorescent lamp such as a cold cathode fluorescent tube as the light source 222, it is superior in color reproducibility to the CIS 231 described later in which a three-color LED or the like is used as the light source.

  A document is manually placed on the platen glass 221 by a user's manual operation when reading the document without using the document feeder 21. In the platen glass 221, the light source 222 and the first mirror 223 are supported by the first carriage 226, and the second mirror 224 and the third mirror 225 are supported by the second carriage 227.

  As the document reading method of the image reading apparatus 2, the scanner unit 22 reads a document placed on the platen glass 221, and the document is loaded by the document feeding unit 21 (ADF), and the document is being transferred. There is an ADF reading mode for reading a document. In the flat bed reading mode, the light source 222 irradiates a document placed on the platen glass 221, and the reflected light for one line in the main scanning direction is reflected in the order of the first mirror 223, the second mirror 224, and the third mirror 225. Then, the light enters the imaging lens 228. The light incident on the imaging lens 228 is imaged on the light receiving surface of the CCD 229. The CCD 229 is a one-dimensional image sensor, and simultaneously processes a document image for one line. The first carriage 226 and the second carriage 227 are configured to be movable in a direction orthogonal to the main scanning direction (sub-scanning direction, arrow Y direction). The first carriage 226 and the second carriage 227 move in the orthogonal direction, and the next line is read.

  In the ADF reading mode, the document feeder 21 takes in the documents placed on the document tray 211 one by one by the pickup roller 212. At this time, the first carriage 226 and the second carriage 227 are disposed below the reading window 230. When the document is transported by the document feeder 21, when the document passes over the reading window 230 provided in the transport path from the transport drum 213 to the paper discharge tray 215, the light source 222 irradiates the document and corresponds to one main scanning line. The reflected light is reflected in the order of the first mirror 233, the second mirror 224, and the third mirror 225, and enters the imaging lens 228. The light incident on the imaging lens 228 is imaged on the light receiving surface of the CCD 229. Subsequently, the document is conveyed by the document feeder 21 and the next line is read.

  Further, the document feeder 21 has a document reversing mechanism (reversing unit) including a switching guide 216, a reversing roller 217, and a reversing conveyance path 218. This document reversing mechanism reverses the front and back of the document whose front side (one side of the document) has been read by the first ADF reading and transports it again to the reading window 230 (scanner unit 22). Read the other side of the document. This document reversing mechanism operates only when reading both sides, and does not operate when reading one side. After reading the back side during single-sided reading and double-sided reading, the switching guide 216 is switched to the upper side, and the document that has passed through the transport drum 213 is discharged to the discharge tray 215 by the discharge roller 214. After the surface reading at the time of double-sided reading, the switching guide 216 is switched to the lower side, and the document that has passed through the transport drum 213 is transported to the reverse transport path 218 by the reverse roller 217. Thereafter, the switching guide 216 is switched to the upper side, the reverse roller 217 rotates in the reverse direction, and the original is fed again to the transport drum 213. Hereinafter, a mode in which both sides of a document are read using the document reversing mechanism is referred to as a double-sided reversal reading mode or a high image quality mode.

  Further, in the ADF reading mode, the image reading apparatus 2 according to the present embodiment causes the CCD 229 (scanner unit 22) to read the surface of the document while the document is being transported as described above. Thus, the back side of the document can be read by the CIS (second reading unit) 231. In this case, the surface of the document conveyed from the document tray 211 by the document feeder 21 is read by the CCD 229 when passing through the reading window 230, and the back surface is read when passing through the location where the CIS 231 is arranged. In CIS231, RGB three-color LEDs or the like are used as light sources. By using the CCD 229 and the CIS 231 in this way, it is possible to read both the front and back sides of a document by a single document transport operation (one pass) from the document tray 211 to the paper discharge tray 215 by the document feeder 21. Hereinafter, a mode in which both sides of a document are read using the CCD 229 and the CIS 231 in this way is referred to as a double-sided simultaneous reading mode or a high-speed mode. In the following description, the scanner unit 22 is referred to as a CCD 229 in order to clarify the difference between the scanner unit 22 and the CIS 231.

  Here, the high image quality mode (double-sided reverse reading mode) and the high-speed mode (double-sided simultaneous reading mode) will be described. In the high image quality mode, both sides of the original are read by the same image sensor (CCD 229). Therefore, even if duplex printing is performed based on the acquired image data, there is no difference in the image quality of the printed images on both sides. However, in the high-speed mode, reading is performed by different image sensors such as the CCD 229 on the front side of the document and the CIS 231 on the back side. Therefore, particularly in the case of a color document, when duplex printing is performed based on the image data acquired by each image sensor, There is a difference in the image quality of the printed images. This is because the CCD 229 and the CIS 231 are configured as an image sensor in which a plurality of light receiving elements are formed on a single chip in addition to the difference in spectral distribution of the light source used when reading an original. In CIS231, since a plurality of solid-state image sensors are connected to form an image sensor, the sensitivity varies between the solid-state image sensors, which is considered to cause a difference in image quality.

  Therefore, in the multi-function device 1 of the present embodiment, in order to solve the above-described difference in image quality, when performing double-sided reading of an original using the ADF reading mode, the user can use the high-quality mode (double-sided reverse reading mode) or the high-speed mode. One of the modes (double-sided simultaneous reading mode) can be selected. In other words, high-quality mode (double-sided reverse reading mode) is used to match the image quality of double-sided printed images, and high-speed mode (priority is given to shortening the reading time even if there is a difference in image quality of double-sided printed images) The user can select the mode using the operation unit 5 to be described later according to the situation. Note that the MFP 1 in the present embodiment is initially set to the high-speed mode, and when an image formation instruction is input without performing any mode setting operation in the reading mode, the multi-function device 1 in the high-speed mode is used. An image reading operation is performed.

  Further, the multifunction machine 1 includes an apparatus main body 3 and a stack tray 6 disposed on the left side of the apparatus main body 3. The apparatus main body 3 includes a plurality of paper feed cassettes 461, a paper feed roller 462 that feeds recording paper from the paper feed cassette 461 one by one and transports it to the recording unit 40, and a recording paper transported from the paper feed cassette 461. And a recording unit 40 for forming an image. The apparatus body 3 also includes a paper feed tray 471 and a feed roller 472 that feeds the originals placed on the paper feed tray 471 one by one toward the recording unit 40.

  The recording unit (image forming unit) 40 is acquired by the neutralization device 421 that neutralizes residual charges from the surface of the photosensitive drum 43, the charging device 422 that charges the surface of the photosensitive drum 43 after neutralization, and the scanner unit 22. A laser beam is output based on the obtained image data to expose the surface of the photosensitive drum 43, and an electrostatic latent image is formed on the surface of the photosensitive drum 43; Formed on the photosensitive drum 43 and developing devices 44K, 44Y, 44M, and 44C that form toner images of each color of cyan (C), magenta (M), yellow (Y), and black (K) on the photosensitive drum 43. A transfer drum 49 on which the toner images of the respective colors are transferred and overlaid, a transfer device 41 for transferring the toner image on the transfer drum 49 to the paper, and heating the paper on which the toner image is transferred. And a fixing device 45 for fixing the toner image onto the sheet. Note that toner is supplied to each color of cyan, magenta, yellow, and black from a toner supply container (toner cartridge) (not shown). In addition, conveyance rollers 463 and 464 that convey the recording paper that has passed through the recording unit 40 to the stack tray 6 or the discharge tray 48 are provided.

  When forming images on both sides of the recording paper, the recording unit 40 forms an image on one side of the recording paper, and then the recording paper is nipped by the conveyance roller 463 on the discharge tray 48 side. In this state, the conveyance roller 463 is reversed to switch back the recording paper, and the recording paper is sent to the paper conveyance path L and conveyed again to the upstream area of the recording unit 40, and an image is formed on the other surface by the recording unit 40. Thereafter, the recording paper is discharged to the stack tray 6 or the discharge tray 48.

  Further, in front of the apparatus main body 3, an operation unit 5 having a display unit through which a user can visually recognize an operation screen and various messages, and operation buttons for inputting various operation commands is provided. FIG. 2 is an example of a front view of the operation unit 5. The operation unit 5 includes a display unit 51, a touch panel 52, a numeric key group 53, various operation buttons 54 to 57, a function selection button 58, and the like. The display unit 51 is configured by an LCD (Liquid Crystal Display), an ELD (Electronic Luminescent Display), or the like, and displays an operation guidance screen for the user such as paper size selection, magnification selection, density selection, and the like. The display unit 51 is formed integrally with the touch panel 52. The touch panel 52 detects a touch position and outputs a detection signal to the control unit 61 described later when a touch operation is performed by the user.

  The numeric key group 53 is for inputting, for example, the number of copies when operating the copy function of the multifunction machine 1 and the telephone number of the transmission destination when operating the facsimile function. The power saving button 54 is a button for setting the multifunction machine 1 in a power saving (low power) mode. The start button 55 is a button for starting a copy operation or a scanner operation, and the stop / clear button 56 is a button for stopping the copy operation or the scanner operation or canceling an input operation. The reset button 57 is a button for setting the display of the display unit 51 and various settings to an initial state or a standard operation state. The function selection button 58 is a button for setting a copy function, a printer function, a scanner function, and a facsimile function.

  FIG. 3 is a block diagram illustrating an electrical configuration of the multifunction machine 1. The same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted. The multi-function device 1 includes a document feeding unit 21, a scanner unit 22, a CIS 231, an operation unit 5, an image processing unit 64, a recording unit 40, a communication unit 66, a power control circuit 67, and a control unit 61.

  The document feeder 21 automatically captures the document placed on the document tray 211 when the document is copied or scanned in the ADF reading mode so that the document can be read by the CCD 229 or the CIS 231. Transport to. The operation unit 5 corresponds to the operation unit 5 shown in FIG. The scanner unit 22, the CIS 231 and the operation unit 5 correspond to the scanner unit 22, the CIS 231 and the operation unit 5 shown in FIGS.

  The image processing unit 64 performs various image processing relating to image data. For example, the image processing unit 64 processes image data acquired by the CCD 229 or the CIS 231 or image data transferred via the communication unit 66 from a personal computer connected via a network, a facsimile machine connected via a public line, or the like. Then, correction processing such as level correction and gamma correction, image data compression or expansion processing, and image processing processing such as enlargement or reduction processing are performed.

  The recording unit 40 forms on the recording paper an image based on image data obtained by the CCD 229 or the CIS 231 or image data transferred from the personal computer or facsimile apparatus via the communication unit 66.

  The communication unit 66 uses a network interface to transmit / receive various data to / from an external device such as a computer or a facsimile machine connected via a network.

  The power control circuit 67 individually controls power supply to the scanner unit 22 and the CIS 231.

  The control unit 61 controls the overall operation of the multifunction machine 1 and is configured by a CPU or the like. The document feeding unit 21, the scanner unit 22, the CIS 231, the operation unit 5, the image processing unit 64, the recording unit 40, and the communication unit 66 operate under the control of the control unit 61. The control unit 61 executes processing based on an operation control program stored in an unillustrated ROM or HDD in accordance with various instruction signals input to the operation unit 5 from the user, The multifunction device 1 is controlled in an integrated manner by outputting an instruction signal, transferring data, and the like, and particularly in the present embodiment, has a function as the power control unit 611.

  The power control unit 611 outputs an instruction related to power supply to the power control circuit 67. In the present embodiment, the multi-function device 1 is in a high image quality mode (double-sided reverse reading mode) in order to save power. When the power control circuit 67 is set, the power control circuit 67 turns off the power supply to the CIS 231.

  Next, processing related to power supply by the control unit 61 will be described. FIG. 4 is a flowchart showing processing related to power supply by the control unit 61.

  As shown in FIG. 4, when start button 55 is pressed (image reading instruction is issued) (YES in step # 1), control unit 61 determines whether the reading operation should be performed in the high-speed mode or not. It is determined whether or not the reading operation should be performed in the mode (step # 2). If the controller 61 determines that the reading operation is performed in the high image quality mode (YES in step # 2), the power control circuit 67 stops the power supply to the CIS 231 (step # 2). 3) When the image reading operation is performed (step # 4), on the other hand, when it is determined that the reading operation is performed in the high speed mode (NO in step # 2), the processing of step # 3 is skipped and step # 3 is performed. Step 4 is executed.

  As described above, in the present embodiment, since the CIS 231 is not used in the high image quality mode, power is supplied to both the CIS 231 and the CCD 229 by causing the power control circuit 67 to stop power supply to the CIS 231. Power saving can be achieved as compared with the case.

  In this case, the following modifications may be employed instead of or in addition to the embodiment.

  [1] In some cases, the peak power consumption (hereinafter referred to as peak power) in the apparatus is desired to be within a desired power value (for example, 1500 (W) or 1000 (W)) because of the rated power of the commercial power supply. In this embodiment, considering this point, a function for setting the peak power by the user is installed, and a function for controlling on / off of power supply to the CIS 231 and the CCD 229 according to the peak power is installed. Yes.

  Specifically, as illustrated in FIG. 5, the MFP 1 according to the present embodiment performs an input for reducing the peak power on the display unit 51 by performing a predetermined operation on a setting screen (not illustrated). A screen is displayed. Normally, the MFP 1 has a peak power of 1500 (W), and in order to save power, when the user wants to reduce the peak power, the input screen is displayed on the display unit 51. FIG. 5 shows an example in which a peak power selection screen in which “1500 (W)” and “1000 (W)” are set as peak powers that can be specified is displayed, and “1500 (W)” is displayed. By pressing the area or the display area of “1000 (W)”, an input for specifying the peak power is performed.

  For example, when the MFP 1 is set to the normal mode and “1000 (W)” is designated on the input screen, the peak power reduction mode in which the peak power is reduced to 1000 (W) is set. When the MFP 1 is set to the peak power reduction mode and “1500 (W)” is designated on the input screen, the peak power is increased to 1500 (W). Mode is set.

  The power control unit 611 (see FIG. 3) controls the power supply to the CIS 231 when the MFP 1 is set to the high image quality mode and is switched from the normal mode to the peak power mode. The circuit 67 is stopped.

  Next, the power supply control process of the control part 61 in this embodiment is demonstrated. FIG. 6 is a flowchart showing power supply control processing by the control unit 61. It is assumed here that “1500 (W)” and “1000 (W)” are set as specifiable peak powers.

  As shown in FIG. 6, when start button 55 is pressed (image formation instruction is issued) (YES in step # 11), control unit 61 determines whether the reading operation should be performed in the high-speed mode. It is determined whether or not the reading operation should be performed in the mode (step # 12). When it is determined that the reading operation is performed in the high image quality mode (YES in step # 12), control unit 61 determines whether or not the peak power is set to 1000 (W) (step #). 13).

  When the peak power is set to 1000 (W) (YES in step # 13), the controller 61 stops the power supply to the CIS 231 by the power control circuit 67 (step # 3). The image reading operation is performed (step # 4). On the other hand, when the peak power is not set to 1000 (W), that is, when the peak power is set to 1500 (W) (NO in step # 13). ), Step # 13 is skipped and step # 14 is executed. Also, when it is determined in step # 12 that the reading operation is performed in the high speed mode (NO in step # 12), control unit 61 skips step # 13 and executes step # 14. To do.

  As described above, when the multifunction device 1 is set to the high image quality mode, the power supply to the CIS 231 is turned off particularly when an instruction to reduce the peak power of the multifunction device 1 is input by the user. Therefore, power saving can be achieved when the user intends. Here, the desired power consumption can be selected from two different peak powers, but the number of peak power settings is not limited to two, and a plurality of peak powers may be set. A desired power consumption may be selected.

  [2] In the above embodiment, the power supply to the CIS 231 is stopped when the double-side reverse reading mode is set as the reading mode. However, when the following configuration is used, the double-side reverse reading is performed. Even when the mode is set, it is preferable to exceptionally supply power to the CIS 231.

  That is, the MFP 1 according to the present embodiment includes a detection unit that detects whether an image composed of image data obtained by the reading operation of the CCD 229 and the CIS 231 is a color image, and a single sheet by the detection unit. When the suitability of the current reading mode is determined according to the detection result of whether or not one of the two images obtained for the document is a color image, and the current reading mode is determined to be inappropriate A determination unit that automatically switches the reading mode to the other reading mode and an input unit for inputting whether to use the function of the determination unit are provided.

  As an example of suitability of the reading mode, for example, when at least one of the front and back images of a single document is a color image, the front image and the back image become relatively prominent. Is an example of a case where it is preferable to perform a reading operation in the double-sided reverse reading mode in order to eliminate a difference in image quality between images, and an example of a case where it is inappropriate to perform the reading operation on the original in the double-sided simultaneous reading mode. It is.

  In such a configuration, when an input for using the function of the determination unit is performed by the input unit, both the CCD 229 and the CIS 231 perform a reading operation so that the detection unit and the determination unit perform operations. Therefore, when the detection unit and the determination unit are operated in a state where the double-sided reverse reading mode is set, it is preferable to supply power to the CIS 231 as well. The detection unit, determination unit, and input unit are not shown.

  Thereby, even if it is a case where it is set to double-sided reverse reading mode, the detection process by a detection part can be performed reliably.

  [3] In the above embodiment, since the CIS 231 is not used in the high image quality mode, the power supply to the CIS 231 is turned off. However, as a mode other than the high image quality mode and the high speed mode, the reversing roller 217 is used. When a mode for reading images on both front and back sides of all documents using only the CIS 231 is provided using the document reversing mechanism including the reversing conveyance path 218, when performing a document reading operation using the mode, Since the CCD 229 is not used, if the power supply to the CCD 229 is turned off, power saving can be achieved as compared with the case where power is supplied to both the CIS 231 and the CCD 229.

  [4] The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, in the above, the configuration of the image reading apparatus and the image forming apparatus according to the present invention and the embodiments of the processing are shown in FIGS. 1 to 6, but these are only examples, and the image reading apparatus and the image forming apparatus according to the present invention The present invention is not limited to the image forming apparatus and the configuration and control described above.

1 is a longitudinal cross-sectional view schematically showing an internal configuration of a multifunction peripheral that is an embodiment of an image forming apparatus according to the present invention. It is an example of the front view of an operation part. FIG. 3 is a block diagram illustrating an electrical configuration of the multifunction machine. It is a flowchart which shows the process which concerns on the electric power supply by a control part. It is a figure which shows the input screen for performing the input which selects peak electric power. It is a flowchart which shows the modification of the process which concerns on the electric power supply by a control part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multifunctional device 2 Image reading apparatus 5 Operation part 21 Document feeding part 22 Scanner part 40 Recording part 61 Control part 611 Power control part 67 Power control circuit 229 CCD
231 CIS

Claims (4)

A document feeder for feeding a document placed on the document placement unit;
A first reading unit that has a reduction optical system image sensor and reads an image of one side of the original conveyed by the original supply unit using the reduction optical system image sensor;
A second reading unit that has a contact optical system image sensor and reads an image of the other surface of the document conveyed by the document feeding unit using the contact optical system image sensor;
A reversing unit for reversing and transporting the original so that the other side is read by the first reading unit after the first reading unit finishes reading one side of the original;
Either one of the first reading unit and the second reading unit reads one side of the document, and after the document is reversed by the reversing unit, the one reading unit is the other side of the document. In both-side reverse reading mode for reading a document and one-time document conveyance by the document feeding unit, the first reading unit reads one side of the document and the second reading unit reads the other side of the document. A control unit that causes each unit to perform a document reading operation in any of the simultaneous reading modes;
A power control circuit for individually controlling power supply to the first and second reading units,
The power control circuit is an image reading apparatus that stops power supply to the unused reading unit of the first and second reading units when the double-sided reverse reading mode is set. An upper limit setting unit for performing input for setting an upper limit value of power consumption of the image reading apparatus;
The power control circuit stops power supply to the unused one of the first and second reading units when the power consumption input by the upper limit setting unit is smaller than a predetermined threshold value. The image reading apparatus according to claim 1. A first input operation unit for selecting a reading mode from the double-sided reverse reading mode and the double-sided simultaneous reading mode;
A detection unit for detecting whether or not an image composed of image data obtained by the reading operation of the first and second reading units is a color image;
A determination unit that determines whether or not the current reading mode is appropriate according to a detection result by the detection unit, and when the current reading mode is determined to be inappropriate, a determination unit that switches the reading mode to the other reading mode;
A second input operation unit for performing an input for setting to a determination mode for causing the determination unit to determine whether the reading mode is appropriate;
In the case where the double-side reverse reading mode is selected by the first input operation unit and the input to set the determination mode is performed by the second input operation unit, the power control circuit The image reading apparatus according to claim 1, wherein power is supplied to both the first and second reading units. An image reading apparatus according to any one of claims 1 to 3,
An image forming apparatus comprising: an image forming unit that forms an image on a recording sheet based on image data obtained by a reading operation of the reading unit.