Patent Publication Number: US-2018034992-A1

Title: Image reading device and image forming apparatus

Description:
INCORPORATION BY REFERENCE 
     This application claims priority to Japanese Patent Application No. 2016-150674 filed on 29 Jul. 2016, the entire contents of which are incorporated by reference herein. 
     BACKGROUND 
     This disclosure relates to an image reading device and an image forming apparatus, and more specifically to an image reading device having contact glass for loading a document thereon and an image forming apparatus including this image reading device. 
     Some image forming apparatus such as copiers perform: document-loaded reading in which a document reading section loaded with a scanner reads a document loaded onto document-loaded reading contact glass by a user&#39;s hand while moving with respect to the document; and document-conveyed reading in which a document conveyed by an automatic document delivery device and passing through document-conveyed reading contact glass is read by the scanner. 
     The image forming apparatus prints an image of the document onto a recording medium based on image data obtained through the reading by the scanner. Through use of the image forming apparatus, the contact glass is contaminated with dust, a foreign substance, etc. As a result of the contamination of the contact glass, the contamination is reflected on printing, leading to printing quality deterioration. Thus, to prevent the printing quality deterioration, various inventions for detecting contamination of contact glass have been suggested. 
     SUMMARY 
     As one aspect of this disclosure, a technology obtained by further improving the technology described above will be suggested. 
     An image reading device according to one aspect of this disclosure includes: contact glass, a document reading section, a reading control section, a first contamination detection section, and a report section. The contact glass loads a document thereon. The document reading section has a moving mechanism capable of reciprocally moving in a predefined document reading direction, and reads the document loaded on the contact glass while the moving mechanism moves in the document reading direction. The reading control section, to cause the document reading section to read the document loaded on the contact glass, causes the document reading section to read the whole contact glass at a rate of once per a predefined number of times N1. The first contamination detection section detects, from image data of the whole contact glass obtained through the reading by the document reading section, contamination of the contact glass present in a region other than a region loaded with the document. The report section, upon detecting by the first contamination detection section the same contamination from all the pieces of image data obtained consecutively a predefined plural number of times M1, reports to a user that the contamination is present on the contact glass. 
     An image forming apparatus according to another aspect of this disclosure includes: the image reading device described above; and an image formation section performing image formation on a recording medium based on the image data of the document obtained through the reading by the image reading device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating outer appearance of an image forming apparatus according to a first embodiment of this disclosure. 
         FIG. 2  is a functional block diagram roughly illustrating main inner configuration of the image forming apparatus according to the first embodiment. 
         FIG. 3  is a transmission plan view schematically illustrating inner configuration of a document reading section. 
         FIG. 4  is a diagram illustrating one example of a display screen displayed at a display section. 
         FIG. 5  is a flowchart illustrating one example of processing operation performed at a control unit. 
         FIG. 6  is a flowchart illustrating one example of the processing operation performed at the control unit. 
         FIGS. 7A to 7C  are diagrams schematically illustrating examples of images indicated by image data obtained consecutively three times in the past, where  FIG. 7A  is the image indicated by the latest image data,  FIG. 7B  is the image indicated by the last image data, and  FIG. 7C  is the image indicated by the second last image data. 
         FIG. 8  is a diagram illustrating one example of a display screen displayed at the display section. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an image reading device and an image forming apparatus according to one embodiment of this disclosure will be described with reference to the drawings.  FIG. 1  is a perspective view illustrating outer appearance of the image forming apparatus according to the first embodiment of this disclosure.  FIG. 2  is a functional block diagram roughly illustrating main inner configuration of the image forming apparatus according to the first embodiment.  FIG. 3  is a transmission plan view schematically illustrating inner configuration of a document reading section. 
     The image forming apparatus  1  is a multifunction peripheral combining together a plurality of functions such as, for example, a copy function, a printer function, a scanner function, and a facsimile function, and includes: a control unit  10 , a document feed section  6 , a document reading section  5 , an image formation section  12 , an image memory  32 , a hard disk drive (HDD)  92 , a fixing section  13 , a paper feed section  14 , an operation section  47 , an open-close sensor  15 , a first document sensor  16 , and a second document sensor  17 . 
     The document reading section  5  irradiates a document by using a light irradiation section and receives light reflected thereon to thereby read an image from the document. The document reading section  5  includes: document-conveyed reading contact glass  161 , document-loaded reading contact glass  162 , a white reference plate  33 , a carriage  34 , a condensing lens  36 , and a charge coupled device (CCD) sensor  37 . Note that the document-loaded reading contact glass  162  is one example of contact glass in the scope of the claims. 
     The white reference plate  33  is a white plate provided between the document-conveyed reading contact glass  161  and the document-loaded reading contact glass  162  along a main scanning direction. The white reference plate  33  is used for shading correction. Image data read from the white reference plate  33  is used as white reference data. 
     The carriage  34  includes: a light source (not illustrated) such as a light emitting diode (LED); and a plurality of mirrors (not illustrated) which reflects read light reflected on the document towards the CCD sensor  37 . The document reading section  5  also includes, for example, a driving motor (not illustrated) formed of a step motor. The carriage  34  is provided in a manner such as to be capable of reciprocally moving in a sub-scanning direction (a document reading direction in this embodiment) as a moving mechanism under control performed by, for example, the control section  100  by a driving force provided from the driving motor. 
     The document feed section  6  feeds a document to be read to the document reading section  5 . Moreover, the document feed section  6  is formed in a manner such as to be capable of opening and closing with respect to a top surface of the document reading section  5  by, for example, a hinge. The document feed section  6  functions as a document press cover upon reading the document loaded on the document-loaded reading contact glass  162  of the document reading section  5 . 
     The image formation section  12  forms, on paper (recording medium), a toner image of an image to be printed. The image memory  32  is a region provided for temporarily storing image data of the document obtained through the reading by the document reading section  5  and temporarily saving data to be printed at the image formation section  12 . 
     The HDD  92  is a large-capacity storage device which stores, for example, the document image read by the document reading section  5 . The fixing section  13  fixes, on the paper through thermal compression, the toner image formed thereon. The paper feed section  14  picks up and conveys paper stored in a paper feed cassette. 
     The open-close sensor  15  detects whether the document feed section  6  is in an open state or in a closed state as the document press cover, and outputs a detection signal to the control unit  10 . The first document sensor  16  detects presence or absence of the document set at the document feed section  6 , and outputs a detection signal to the control unit  10 . The second document sensor  17  includes a plurality of light sensors (not illustrated) which is provided below the document-loaded reading contact glass  162  in correspondence with document sizes, detects the presence or absence of the document loaded on the document-loaded reading contact glass  162  and then the document size, and outputs a detection signal to the control unit  10 . 
     The operation section  47  receives, from an operator, instructions such as an image formation operation execution instruction, a document reading operation execution instruction, etc. for various types of operation and processing executable by the image forming apparatus  1 . The operation section  47  includes a display section  473  which displays, for example, an operation guide to the operator. The display section  473  is a touch panel, and the operator can touch buttons and keys displayed on a screen to operate the image forming apparatus  1 . 
     The control unit  10  includes: a processor, a random access memory (RAM), a read only memory (ROM), and a dedicated hardware circuit. The processor is, for example, a central processing unit (CPU), an application specific integrated circuit (ASIC), or a micro-processing unit (MPU). The control unit  10  includes: a control section  100  in charge of overall operation control of the image forming apparatus  1 ; an operation reception section  101 , a reading control section  102 , a first contamination detection section  103 , a second contamination detection section  104 , a report section  105 , and a setting section  106 . 
     The control unit  10  functions as the control section  100 , the operation reception section  101 , the reading control section  102 , the first contamination detection section  103 , the second contamination detection section  104 , the report section  105 , and the setting section  106  through operation in accordance with control programs installed in the HDD  92 . Note that, however, the control section  100 , etc. can each be formed by a hardware circuit without depending on the operation performed by the control unit  10  in accordance with the control programs. Hereinafter, unless otherwise specified, the same applies to each embodiment. 
     The control section  100  is connected to the document feed section  6 , the document reading section  5 , the image formation section  12 , the image memory  32 , the HDD  92 , the fixing section  13 , the paper feed section  14 , the operation section  47 , the open-close sensor  15 , the first document sensor  16 , and the second document sensor  17  to perform driving control of each of these sections. 
     The operation reception section  101  receives operation from the user. 
     The reading control section  102  performs, for example, control of causing the document reading section  5  to read the document loaded on the document-loaded reading contact glass  162 . 
     The first contamination detection section  103  detects, from image data of the whole document-loaded reading contact glass  162  obtained through the reading by the document reading section  5 , contamination of the document-loaded reading contact glass  162  present in a region other than a region loaded with a document of a predefined size. 
     For example, the reading control section  102  causes the document reading section  5  to perform document reading operation on the document-loaded reading contact glass  162  present in the region other than the region loaded with the document of the predefined size, and acquires image data obtained though the reading of the region other than the region loaded with the document of the predefined size. The first contamination detection section  103  determines whether or not the acquired image data includes image data indicating an image formed by a predefined number of pixel groups including a pixel value other than a pixel value indicating white. Note that this image is hereinafter referred to as a contaminated image. Here, the pixel value indicating white is, for example, a 256 value, which is, for example, in a range between 240 and 256. Moreover, the predefined number is not specifically limited, but is a number of pixels required for forming an image of such a size which permits user&#39;s confirmation with his or her naked eye, for example, 7168 pixels with a resolution of 600DPI×600DPI. The first contamination detection section  103 , upon determination that the aforementioned acquired image data includes the image data indicating the aforementioned contaminated image, detects that contamination is present in the region of the document-loaded reading contact glass  162  other than the region loaded with the document of the predefined size. 
     Note that a desirable document as the document of the predefined size is a document of an A4 size which is most frequently used in business scenes. Thus, the aforementioned predefined size is described as an A4 size in this embodiment. 
     The second contamination detection section  104  detects the contamination of the document-loaded reading contact glass  162  from the image data of the whole document-loaded reading contact glass  162  loaded with no document which data has been obtained through the reading by the document reading section  5 . 
     For example, the reading control section  102  causes the document reading section  5  to perform the document reading operation on the document-loaded reading contact glass  162  loaded with no document, and thereby acquires the image data of the whole document-loaded reading contact glass  162 . The second contamination detection section  104  determines whether or not the aforementioned acquired image data includes the image data indicating the image formed by the predefined number of pixel groups including the pixel value other than the pixel value indicating white. The second contamination detection section  104 , upon determination that the aforementioned acquired image data includes the image data indicating the aforementioned contaminated image, detects that contamination is present on the document-loaded reading contact glass  162 . 
     Specifically, the second contamination detection section  104  is capable of detecting the contamination of the document-loaded reading contact glass  162  which cannot be detected in the first contamination detection section  103  and which is present in a region loaded with a document of, for example, an A4 size as the aforementioned predefined size. 
     The report section  105  notifies the user that the contamination is present on the document-loaded reading contact glass  162 . 
     Upon receiving, by the operation reception section  101  from the user, a request for setting to a contamination detection mode in which the contamination of the document-loaded reading contact glass  162  is detected, the setting section  106  sets this contamination detection mode. For example, upon receiving, by the operation reception section  101  from the user, a request for displaying a contamination detection mode setting screen, the setting section  106  displays, at the display section  473  ( FIGS. 1 and 2 ), a “contamination detection mode setting” screen D 1 , as illustrated in  FIG. 4 , for detecting the contamination of the document-loaded reading contact glass  162 . 
     Formed on the “contamination detection mode setting” screen D 1  are: a selection button B 1  on which “SET” for selecting the contamination detection mode setting is written; a selection button B 2  on which “NO SET” is written; and an input box L 1  for inputting an interval (a number of times of scanning performed by the document reading section  5 ) at which this contamination is detected. The control section  100  causes the image forming apparatus  1  to operate in this set mode. 
     Upon receiving, by the operation reception section  101 , selection of the selection button B 1  on which “SET” is written, the setting section  106  sets the contamination detection mode and also sets, at 0, the count values C 1  and C 2  for counting the number of times (a number of times of reading) of scanning performed by the document reading section  5 . The count value C 1  is used for counting the number of times of reading of the document of the A4 size as the predefined size, and the count value C 2  is used for counting the number of times of document reading regardless of the size of the document. Moreover, the setting section  106  sets a numerical value (for example, 50 times) received by the operation reception section  101  and inputted in an input box L 1  at a number of times N1 to be used as a contamination detection trigger. 
     Next, one example of processing operation performed at the control unit  10  will be described based on flowcharts illustrated in  FIGS. 5 and 6 . Note that this processing operation is performed when, after reception of a copy instruction from the user by the operation reception section  101 , the control section  100  has determined, based on the detection signal provided from the first document sensor  16 , that no document is set at the document feed section  6 . 
     First, the reading control section  102  determines whether or not the contamination detection mode has been set by the setting section  106  (S 1 ). Upon determination by the reading control section  102  that the contamination detection mode has not been set by the setting section  106  (NO in S 1 ), the reading control section  102  controls driving of the carriage  34  in a conventional manner in accordance with the size of the document, loaded on the document-loaded reading contact glass  162 , which size is required based on a detection signal provided from the second document sensor  17 , causes the document reading section  5  to read the document image (S 2 ), causes the image memory  32  to store image data of a document region obtained through the reading by the document reading section  5  (S 3 ), and moves the carriage  34  to a home position HP ( FIG. 3 ) as a predefined standby position (S 4 ), and the image formation section  12  performs image formation on the recording medium based on the image data of the document stored in the image memory  32  (S 5 ). 
     On the other hand, upon determination by the reading control section  102  that the contamination detection mode has been set by the setting section  106  (YES in S 1 ), the reading control section  102  determines based on the detection signal provided from the second document sensor  17  whether or not the size of the document loaded on the document-loaded reading contact glass  162  is an A4 size (S 6 ). More precisely, the reading control section  102  determines whether or not the document is an A4 size and loaded longitudinally. 
     Upon determination by the reading control section  102  that the size of the document loaded on the document-loaded reading contact glass  162  is an A4 size (YES in S 6 ), the reading control section  102  adds 1 to the count value C 1  (S 7 ), and determines whether or not the count value C 1  is equal to or greater than the number of times N1 (for example, 50 times) (S 8 ). 
     Upon determination by the reading control section  102  that the count value C 1  is equal to or greater than the number of times N1 (that is, a number of times of reading of the A4-sized document has reached 50 times) (YES in S 8 ), the reading control section  102  controls the driving of the carriage  34 , causes the document reading section  5  to read not only a region of the document (A4 region here) but also the whole document-loaded reading contact glass  162  (S 9 ), and resets the count value C 1  at 0 (S 10 ). 
     Subsequently, the reading control section  102  stores, into the HDD  92 , the image data of the whole document-loaded reading contact glass  162  which has been obtained through the reading by the document reading section  5  (S 11 ) and also causes the image memory  32  to store the image data of the document image obtained through the reading by the document reading section  5  (S 12 ), and the image formation section  12  performs image formation on the recording medium based on the image data of the document stored in the image memory  32  (S 13 ). 
     Then the first contamination detection section  103  detects, from latest image data of the document-loaded reading contact glass  162  which has been stored in the HDD  92  and which has been obtained through the reading by the document reading section  5 , an image (that is, contamination) present in the region other than the region loaded with the document (S 14 ). The first contamination detection section  103  determines whether or not an image (contamination) is present in any region other than the region loaded with the document (S 15 ). Any region other than the region loaded with the A4-sized document should originally be white. In other words, when color data (image) of a color other than white in addition to the region loaded with the A4-sized document has been detected, it can be assumed that contamination is present on the document-loaded reading contact glass  162 . 
     Upon determination by the first contamination detection section  103  that the image (contamination) is present in any region other than the region loaded with the document (YES in S 15 ), the first contamination detection section  103  performs matching between the pieces of image data of the whole document-loaded reading contact glass  162  which data has been obtained a predefined consecutive plural number of times M1 (the consecutive three times in the past including this time, the last time, and the second last time) and which has been stored in the HDD  92 , and determines whether or not the same contamination could be detected from all these pieces of image data (S 16 ). As described above, the first contamination detection section  103  detects the same contamination by performing the matching between the pieces of image data obtained the aforementioned plural number of times M1, thus permitting accurate detection of this same contamination. 
       FIGS. 7A to 7C  are diagrams schematically illustrating examples of the images indicated by the pieces of image data obtained consecutively three times in the past, where  FIG. 7A  is the image indicated by the latest image data,  FIG. 7B  is the image indicated by the last image data, and  FIG. 7C  is the image indicated by the second last image data, respectively illustrating cases where the same contamination F 1  is present in regions Ea to Ec other than regions loaded with A4-sized documents Ga to Gc. 
     Upon determination by the first contamination detection section  103  that the same contamination could be detected from all the pieces of image data obtained consecutively three times in the past (YES in S 16 ), the first contamination detection section  103  detects a position of this contamination on the document-loaded reading contact glass  162  (S 17 ), the report section  105  displays a display screen D 2  as illustrated in  FIG. 8  at the display section  473 , thereby presenting the user that the document-loaded reading contact glass  162  has this contamination and further information indicating the position of this contamination (S 18 ), and then the processing proceeds to S 31  illustrated in  FIG. 6 , in which processing for detecting the contamination of the document-loaded reading contact glass  162  including the region loaded with the A4-sized document is performed. 
     On the other hand, when the first contamination detection section  103  has determined that no image (contamination) is present in any region other the region loaded with the documents (NO in S 15 ), or when the first contamination detection section  103  has determined that the same contamination cannot be detected from all the pieces of image data obtained consecutively three times in the past (NO in S 16 ), there is no need of reporting the presence of contamination, and thus the processing proceeds directly to S 31  ( FIG. 6 ), skipping S 17  and S 18 . 
     Moreover, upon determination by the reading control section  102  that the size of the document loaded on the document-loaded reading contact glass  162  is not an A4 size (NO in S 6 ), or upon determination by the reading control section  102  that the count value C 1  is not equal to or greater than the number of times N1 (that is, the number of times of reading the A4-sized document has not reached 50 times) (NO in S 8 ), the reading control section  102  controls the driving of the carriage  34  in a conventional manner in accordance with the size of the document loaded on the document-loaded reading contact glass  162 , which size is required based on the detection signal provided from the second document sensor  17 , and causes the document reading section  5  to read the document image (S 19 ), causes the image memory  32  to store the image data of the document region obtained through the reading by the document reading section  5  (S 20 ), and moves the carriage  34  to the home position HP (S 21 ), and the image formation section  12  performs image formation on the recording medium based on the image data of the document stored in the image memory  32  (S 22 ), and then the processing proceeds to S 31  ( FIG. 6 ). 
     In S 31  illustrated in  FIG. 6 , the reading control section  102  adds 1 to the count value C 2  (S 31 ), and determines whether or not the count value C 2  is equal to or greater than a predefined number of times N2 (S 32 ). The number of times N2 is set at a number of times greater than the number of times N1, for example, set at approximately 200 times. 
     Upon determination by the reading control section  102  that the count value C 2  is equal to or greater than the number of times N2 (that is, the number of times of the document reading has reached 200 times) (YES in S 32 ), the reading control section  102  determines based on the detection signal provided from the open-close sensor  15  whether or not the document feed section  6  functioning as the document press cover of the document-loaded reading contact glass  162  has been opened and closed (S 33 ). 
     Upon determination by the reading control section  102  that the document feed section  6  has been opened and closed (YES in S 33 ), the reading control section  102  determines based on the detection signal provided from the second document sensor  17  whether or not the document is loaded on the document-loaded reading contact glass  162  (S 34 ). 
     Upon determination by the reading control section  102  that no document is loaded on the document-loaded reading contact glass  162  (NO in S 34 ), the reading control section  102  controls the driving of the carriage  34  and causes the document reading section  5  to read the whole document-loaded reading contact glass  162  loaded with no document (S 35 ), resets the count value C 2  at 0 (S 36 ), the reading control section  102  causes the HDD  92  to store all the pieces of image data of the whole document-loaded reading contact glass  162  obtained through the reading by the document reading section  5  (S 37 ), and moves the carriage  34  to the home position HP (S 38 ). 
     Subsequently, the second contamination detection section  104  detects, from among the latest image data of the whole document-loaded reading contact glass  162  loaded with no document which image data has been stored in the HDD  92  and which has been obtained through the reading by the document reading section  5 , any image (contamination) present on the document-loaded reading contact glass  162  (S 39 ), and the second contamination detection section  104  determines whether or not any image (contamination) is present on the document-loaded reading contact glass  162  (S 40 ). 
     Upon determination by the second contamination detection section  104  that any image (contamination) is present on the document-loaded reading contact glass  162  (YES in S 40 ), the second contamination detection section  104  performs matching between the pieces of image data of the whole document-loaded reading contact glass  162  loaded with no document which image data has been obtained consecutively the predefined plural number of times M2 and which has been stored in the HDD  92  (three consecutive times in the past including this time, the last time, and the second last time here), and determines whether or not the same contamination could be detected from all these pieces of image data (S 41 ). As described above, the second contamination detection section  104  detects the same contamination by performing the matching between the pieces of image data obtained the aforementioned plural number of times M2, thus permitting accurate detection of the same contamination. 
     Upon determination by the second contamination detection section  104  that the same contamination could be detected from all the pieces of image data obtained consecutively three times in the past (YES in S 41 ), the second contamination detection section  104  detects a position of this contamination on the document-loaded reading contact glass  162  (S 42 ), and the report section  105  presents, via the display section  473 , the user that this contamination is present on the document-loaded reading contact glass  162  and further the information indicating the position of this contamination (S 43 ). 
     On the other hand, upon determination by the second contamination detection section  104  that no image (contamination) is present on the document-loaded reading contact glass  162  (NO in S 40 ), or upon determination by the second contamination detection section  104  that the same contamination cannot be detected from all the pieces of image data obtained consecutively three times in the past (NO in S 41 ), there is no need of reporting the presence of the contamination, and thus this processing operation directly ends. 
     Moreover, upon determination by the reading control section  102  that the count value C 2  is not equal to or greater than the number of times N2 (that is, the number of times of the document reading has not reached 200 times) (NO in S 32 ) or upon determination by the reading control section  102  that any document is loaded on the document-loaded reading contact glass  162  (YES in S 34 ), there is no need of reading the whole document-loaded reading contact glass  162  for the contamination detection, and thus the reading control section  102  moves the carriage  34  to the home position HP (S 44 ), and this processing operation ends. 
     Here, in typical image reading devices, document-loaded reading contact glass is frequently touched by a human&#39;s hand, and may be contaminated by stain in addition to dust and a foreign substance. Some of the typical image reading devices are known to detect contamination of document-conveyed reading contact glass. Moreover, some typical image reading devices have been suggested which detect contamination of the document-loaded reading contact glass, and upon determining presence or absence of any document on the document-loaded reading contact glass and determining that any document is absent, the image reading device detects contamination of the document-loaded reading contact glass and displays results of the detection. That is, when any document is absent, it is required to perform special processing only for contamination detection, for example, driving a scanner, which raises a problem of deteriorated productivity. 
     On the contrary, according to the first embodiment described above, to cause the document reading section  5  to read the document loaded on the document-loaded reading contact glass  162 , the document reading section  5  is caused to read the whole document-loaded reading contact glass  162  at a rate of once per the predefined number of times N1 (for example, a rate of once per 50 times), and the contamination of the document-loaded reading contact glass  162  present in the region other than the region loaded with the document is detected from the image data of the whole document-loaded reading contact glass  162  obtained through the reading by the document reading section  5 . That is, the document reading section  5  is not driven only for the contamination detection, thus permitting prevention of the productivity deterioration. 
     Moreover, upon detecting the same contamination from all the pieces of image data obtained consecutively the predefined plural number of times M1 (for example, three times), the user is notified that this contamination is present on the document-loaded reading contact glass  162 . For example, when the same contamination has been detected consecutively three times, the user is notified of the presence of this contamination. Consequently, this can prevent erroneous notification of the presence of the contamination to the user although no contamination is actually present. 
     Further, according to the first embodiment described above, not only when any document is loaded, but also when no document is loaded, the image data of the whole document-loaded reading contact glass  162  is regularly read to detect the contamination of the document-loaded reading contact glass  162  from this image data, which therefore permits detection of not only the contamination located outside of the region loaded with the document but also contamination located in the region loaded with the document. 
     Reading of this image data when no document is loaded is special processing only for the contamination detection, leading to a risk of deteriorated productivity, but since a frequency of this reading is relatively small, for example, approximately once per 200 times, the productivity deterioration can be suppressed. 
     Moreover, the reading control section  102  causes the document reading section  5  to read the document loaded on the document-loaded reading contact glass  162  and then moves the carriage  34  to the home position HP in normal occasions (S 4  and S 21  of  FIG. 5 ), but to cause the document reading section  5  to read the whole document-loaded reading contact glass  162  when no document is loaded, the carriage  34  is not immediately moved to the home position HP, the document reading section  5  is first caused to read the whole document-loaded reading contact glass  162  loaded with no document, and then the carriage  34  is moved to the home position HP (S 38  of  FIG. 6 ). Consequently, this can efficiently move the carriage  34 , suppressing the productivity deterioration. 
     This disclosure is not limited to the configuration of the embodiment described above, and thus various modifications can be made. Moreover, the embodiment has been described above, referring to the multifunction peripheral of the image forming apparatus as one embodiment of the image reading device according to this disclosure, but this is just one example, and another electronic device, such as an image reading device having a copy function, a printer function, a scanner function, and a facsimile function may be used. 
     Moreover, the configuration and the processing indicated in the embodiment described above referring to  FIGS. 1 through 8  are just one embodiment of this disclosure, and this disclosure is not limited in any way to these configuration and processing. 
     Various modifications and alterations of this disclosure will be apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that this disclosure is not limited to the illustrative embodiments set forth herein.