Patent Publication Number: US-8534664-B2

Title: Image forming apparatus and feed mechanism

Description:
This application is based on and claims the benefit of priority from Japanese Patent Application No. 2010-173844, filed on 2 Aug. 2010, the content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image forming apparatus having a feed mechanism that feeds image formation target materials. In addition, the present invention relates to a feed mechanism that feeds image formation target materials. 
     2. Related Art 
     Conventionally, image forming apparatuses such as copy machines include a housing in which an image forming portion is disposed to be housed, and a feed mechanism (device) that feeds paper (image formation target materials) into the housing. 
     The feed mechanism of an image forming apparatus typically includes a feed roller that feeds paper (image formation target material) to inside of the housing, and a pad unit (separation unit) that has a separation pad member (separation member) disposed so as to oppose the feed roller and insert, therebetween and the feed roller, paper. The feed roller and pad unit of the feed mechanism are consumable items that tend to wear and deteriorate. As a result, worn or deteriorated consumable items such as the feed roller and pad unit in the feed mechanism are replaced by a user with a new feed roller or pad unit. 
     In this operation, a user may forget to install the new feed roller or pad unit into the feed mechanism when replacing the feed roller or pad unit. In a case of the feed mechanism being operated in a state in which the user has forgotten to install the new feed roller or pad unit, a malfunction will occur such as a paper jam in the feed mechanism. 
     To address this, an image forming apparatus has been proposed that includes a feed roller detection means, for example, as a technology to suppress forgetting to install a new feed roller in the feed mechanism. 
     However, with such a feed mechanism, the feed roller detection means is not a means for detecting the presence of the pad unit including the separation pad member. 
     In addition, the pad unit including the separation pad member is covered by the feed roller in the state installed in the feed mechanism, and thus it may be difficult to determine whether it is installed or not from outside. 
     Furthermore, even in a state in which the unit including the separation pad member is not installed in the feed mechanism, paper may be disposed at a position that can be fed by the feed roller. In such a case, there has been a problem in that a severe paper jam occurs from a plurality of sheets of paper being fed at one time when the feed roller is rotationally driven. Moreover, there has been a problem in that a failure will occur in the feed mechanism or the image forming apparatus equipped with this feed mechanism due to such a severe paper jam. 
     SUMMARY OF THE INVENTION 
     The present invention has an object of providing an image forming apparatus having a feed mechanism that can suppress malfunctions that may arise in a state in which a separation unit including a separation member is not installed. 
     In addition, the present invention has an object of providing a feed mechanism that can suppress malfunctions that may arise in a state in which the separation unit is not installed. 
     The present invention relates to an image forming apparatus, comprising: an image forming portion; a housing in which the image forming portion is disposed to be housed; a placement portion on which at least one image formation target material can be placed; a feed roller that is disposed to oppose an upper surface of at least one image formation target material placed on the placement portion to be disposed at a predetermined feed position, and feeds a topmost image formation target among the at least one image formation target material to inside of the housing; a supply feed path in which image formation target materials are fed; a separation unit that is disposed at a predetermined mounting part so as to configure a portion of the supply feed path and is detachable relative to the mounting part, and includes a separation member that is disposed to oppose the feed roller on a more downstream side in a feed direction in which the image formation target materials are fed than the feed position, and is disposed so as to insert, therebetween and the feed roller, the image formation target material; a position detection part can detect that at least one image formation target material is disposed at a predetermined position on the placement portion, and includes: a detection member that can move between an initial position that is a position at which a leading end of the at least one image formation target material is abutted in a case of the at least one image formation target material being moved from the predetermined position to the feed position or a feed setup position that is in the vicinity of the feed position and is for moving image formation target material to the feed position by a predetermined lift member, and a retracted position retracted from the placement portion in a state in which the at least one image formation target material is disposed at the feed position or the feed setup position, and a detector which detects that the at least one image formation target material is disposed at the feed position or the feed setup position in a case of having detected that the detection member is at the retracted position; and a restricting member that is disposed at a stored position opposing the detection member to interpose the separation unit therewith, in a mounted state in which the separation unit is mounted to the mounting part, and is disposed at a restricting position that restricts the detection member from moving from the initial position to the retracted position by abutting the detection member, in a detached state in which the separation unit is detached from the mounting part. 
     In addition, the present invention relates to a feed mechanism, comprising: a placement portion on which at least one sheet material can be placed; a feed roller that is disposed to oppose an upper surface of at least one sheet material placed on the placement portion to be disposed at a predetermined feed position, and feeds a topmost sheet among the at least one sheet material in a predetermined feed direction; a supply feed path in which sheet materials are fed; a separation unit that is disposed at a predetermined mounting part so as to configure a portion of the supply feed path and is detachable relative to the mounting part, and includes a separation member that is disposed to oppose the feed roller on a more downstream side in a feed direction in which the sheet materials are fed than the feed position, and is disposed so as to insert, therebetween and the feed roller, the sheet material; a detection member that is disposed in order to detect that at least one sheet material is disposed on the placement portion, and can move between an initial position that is a position at which a leading end of the at least one sheet material is abutted in a case of the at least one sheet material being moved from the predetermined position to the feed position or a feed setup position that is in the vicinity of the feed position and is for moving sheet material to the feed position by a predetermined lift member, and a retracted position retracted from the placement portion, in a state in which the at least one sheet material is disposed at the feed position or the feed setup position; and a restricting member that is disposed at a stored position opposing the detection member to interpose the separation unit therewith in a mounted state in which the separation unit is mounted to the mounting part, and is disposed at a restricting position that restricts the detection member from moving from the initial position to the retracted position by abutting the detection member, in a detached state in which the separation unit is detached from the mounting part. 
     In addition, the present invention relates to a image forming apparatus, comprising: an image forming portion; a housing in which the image forming portion is disposed to be housed; a placement portion on which at least one image formation target material can be placed; a feed roller that is disposed to oppose an upper surface of at least one image formation target material placed on the placement portion to be disposed at a predetermined feed position, and feeds a topmost image formation target among the at least one image formation target material to inside of the housing; a supply feed path in which image formation target materials are fed; a separation unit that is disposed at a predetermined mounting part so as to configure a portion of the supply feed path and is detachable relative to the mounting part, and includes a separation member that is disposed to oppose the feed roller on a more downstream side in a feed direction in which the image formation target materials are fed than the feed position, and is disposed so as to insert, between and the feed roller, the image formation target material; a position detection part that can detect that at least one image formation target material is disposed at a predetermined position on the placement portion, and includes: a detection member that can move between an initial position that is a position at which a leading end of the at least one image formation target material is abutted in a case of the at least one image formation target material being moved from the predetermined position to the feed position or a feed setup position that is in the vicinity of the feed position and is for moving image formation target material to the feed position by a predetermined lift member, and a retracted position retracted from the placement portion in a state in which the at least one image formation target material is disposed at the feed position or the feed setup position, and a detecting part which can detect that the detection member is at the retracted position; and a restricting member that is disposed at a stored position opposing the detection member to interpose the separation unit therewith, in a mounted state in which the separation unit is mounted to the mounting part, and is disposed at a restricting position that restricts the detection member from moving from the initial position to the retracted position by abutting the detection member, in a detached state in which the separation unit is detached from the mounting part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view illustrating the arrangement of each constitutional element of a copy machine  1  of the present invention; 
         FIG. 2  is a perspective view when the entirety of a feed mechanism  600  of the copy machine  1  shown in  FIG. 1  is viewed from above at an angle from the right lateral face side of a device main body M; 
         FIG. 3  is a perspective view when a state in which a paper feed roller  66  of the feed mechanism  600  is removed in the copy machine  1  shown in  FIG. 1  is viewed from above at an angle from the right lateral face side of the device main body M; 
         FIG. 4  is a perspective view in which a region in the vicinity of a detection member  621  in  FIG. 3  is enlarged; 
         FIG. 5  is a perspective view in which a region in the vicinity of the detection member  621  is enlarged in a state where a pad unit  610  in  FIG. 4  is detached; 
         FIG. 6  is an enlarged perspective view illustrating an installed state of a restricting member  630 ; 
         FIG. 7  is a block diagram illustrating a configuration of a control system of the copy machine  1 ; 
         FIG. 8A  is a view illustrating a state in which the pad unit  610  is mounted to a mounting part  602  of a casing  601 ; 
         FIG. 8B  is a view illustrating a state in which paper T is moved from the state in  FIG. 8A  in the arrow F 1  direction and the detection member  621  pivotally moves; 
         FIG. 8C  is a view illustrating a state in which a lift plate  603  rises from the state in  FIG. 8B ; 
         FIG. 8D  is a view illustrating a state in which the pad unit  610  is made to move in the arrow F 4  direction after the paper feed roller  66  has been removed; 
         FIG. 8E  is a view illustrating a state in which the pad unit  610  is made to move further in the arrow F 4  direction from the state in  FIG. 8D  to be detached from the mounting part  602 ; and 
         FIG. 9  is a flowchart illustrating operations of the control system of the copy machine  1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, preferred modes for carrying out the present invention will be explained while referring to the drawings. 
     The overall configuration of a copy machine  1  as an image forming apparatus of the present embodiment will be explained according to  FIG. 1 .  FIG. 1  is a view illustrating an arrangement of each constitutional element of the copy machine  1 . 
     As shown in  FIG. 1 , the copy machine  1  as an image forming apparatus includes an image reading device  300  that is disposed at an upper side of the copy machine  1  in the vertical direction Z, and an apparatus main body M that is disposed at a lower side of the copy machine  1  in the vertical direction Z and forms a toner image on paper T, which serves as an image formation target material of sheet-shape, based on image information read from the image reading device  300 . 
     It should be noted that, in the explanation of the copy machine  1 , the sub scanning direction X is also referred to as the “horizontal direction” of the copy machine  1 , and the main scanning direction Y (direction penetrating into  FIG. 1 ) is also referred to as the “front-back direction” of the copy machine  1 . The vertical direction Z of the copy machine  1  is orthogonal to the sub scanning direction X and the main scanning direction Y. 
     First, the image reading device  300  will be explained. 
     As shown in  FIG. 1 , the image reading device  300  includes a cover member  70 , and a reading portion  301  that reads an image of an original G. 
     The cover member  70  is connected to be openable and closeable to the reading portion  301  by a connecting portion that is not illustrated. The cover member  70  has a function of protecting a reading surface  302 A, which is described later. 
     The reading portion  301  includes a housing  306 , and the reading surface  302 A that is disposed at an upper side of the housing  306 . Furthermore, in an internal space  304  of the housing  306 , the reading portion  301  includes: a lighting portion  340  that has a light source; a plurality of mirrors  321 ,  322  and  323 ; a first frame body  311  and a second frame body  312  that move in the sub scanning direction X; an imaging lens  357 ; a CCD  358  serving as a reading device; and a CCD substrate  361  that performs predetermined processing on image information read by the CCD  358  and causes the image information to be output to an apparatus main body M side. The lighting portion  340  and the first mirror  321  are housed in the first frame body  311 . The second mirror  322  and the third mirror  323  are housed in the second frame body  312 . 
     The reading surface  302 A extends in directions orthogonal to the sub scanning direction X and the main scanning direction Y, and covers a large part of the reading portion  301  in the sub scanning direction X. The original G is placed on the reading surface  302 A. The first frame body  311  and the second frame body  312  each move in the sub scanning direction X while maintaining the length of a light path H described later (light path length) to be constant. The image of the original G placed on the reading surface  302 A is thereby read. 
     In the internal space  304  of the housing  306 , the plurality of mirrors  321 ,  322  and  323  form the light path H for causing the light from the original G to enter the imaging lens  357 . In addition, since the first frame body  311  moves in the sub scanning direction X at a constant speed A and the second frame body  312  moves in the sub scanning direction X at a constant speed A/ 2 , the length of the light path H is kept constant even during an image reading operation. The details of the reading portion  301  will be described later. 
     The apparatus main body M will be explained next. 
     The apparatus main body M has an image forming portion GK that forms a predetermined toner image on the paper T based on predetermined image information, and a paper feeding/ejection portion KH that feeds the paper T to the image forming portion GK and ejects the paper T on which a toner image has been formed. 
     The external form of the apparatus main body M is configured by a case body BD serving as a housing portion. 
     As shown in  FIG. 1 , the image forming portion GK includes: photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  as image carriers (photoreceptors); charging portions  10   a ,  10   b ,  10   c  and  10   d ; laser scanner units  4   a ,  4   b ,  4   c  and  4   d  serving as exposure units; developing units  16   a ,  16   b ,  16   c  and  16   d ; toner cartridges  5   a ,  5   b ,  5   c  and  5   d ; toner supply parts  6   a ,  6   b ,  6   c  and  6   d ; drum cleaning parts  11   a ,  11   b ,  11   c  and  11   d ; static eliminators  12   a ,  12   b ,  12   c  and  12   d ; an intermediate transfer belt  7 ; primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d ; a secondary transfer roller  8 ; a counter roller  18 ; and a fusing portion  9 . 
     As shown in  FIG. 1 , the paper feeding/ejection portion KH includes paper feed cassettes  52 , a manual paper feed part  64 , a paper feed path L for the paper T, a resist roller pair  80 , and first paper ejection part  50   a , and a second paper ejection part  50   b . It should be noted that, the paper feed path L is a collection of a first paper feed path L 1 , a second paper feed path L 2 , a third paper feed path L 3 , a manual paper feed path La, a reverse paper feed path Lb, and a post-processing paper feed path Lc, as described later. 
     Each component of the image forming portion GK and the paper feeding/ejection portion KH will be explained in detail hereinafter. 
     First, the image forming portion GK will be explained. 
     In the image forming portion GK, charging by the charging parts  10   a ,  10   b ,  10   c  and  10   d ; exposure by the laser scanner units  4   a ,  4   b ,  4   c  and  4   d ; developing by the developing units  16   a ,  16   b ,  16   c  and  16   d ; primary transfer by the intermediate transfer belt  7  and the primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d ; static elimination by the static eliminators  12   a ,  12   b ,  12   c  and  12   d ; and cleaning by the drum cleaning parts  11   a ,  11   b ,  11   c  and  11   d  are performed in order from an upstream side to a downstream side along the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. 
     In addition, in the image forming portion GK, secondary transfer by the intermediate transfer belt  7 , the secondary transfer roller  8  and the counter roller  18 , as well as fusing by the fusing portion  9 , are performed. 
     The photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  are each made of a cylindrically shaped member, and function as a photoreceptor or an image carrier. Each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  is disposed to be rotatable in the directions of the arrows in  FIG. 1  about an axis extending in a direction orthogonal to the direction of movement of the intermediate transfer belt  7 . An electrostatic latent image can be formed on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d.    
     The charging parts  10   a ,  10   b ,  10   c  and  10   d  are disposed to oppose the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. The charging parts  10   a ,  10   b ,  10   c  and  10   d  uniformly negatively charge (negative polarity) or positively charge (positive polarity) the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. 
     The laser scanner units  4   a ,  4   b ,  4   c  and  4   d  function as exposure units and are disposed to be spaced apart from the surfaces of the respective photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d . The laser scanner units  4   a ,  4   b ,  4   c  and  4   d  are configured to each include a laser light source, a polygonal mirror, a polygonal mirror drive motor, and the like, which are not illustrated. 
     The laser scanner units  4   a ,  4   b ,  4   c  and  4   d  scan and expose the surface of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively, based on image information related to an image read by the reading portion  301 . By being scanned and exposed by the laser scanner units  4   a ,  4   b ,  4   c  and  4   d , the electric charge of an exposed part of the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  is removed. In this way, an electrostatic latent image is formed on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d.    
     The developing units  16   a ,  16   b ,  16   c  and  16   d  are provided so as to correspond to the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   b , respectively, and are disposed to oppose the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. The developing units  16   a ,  16   b ,  16   c  and  16   d  each cause toner of each color to adhere to the electrostatic latent image formed on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , to form a color toner image on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d . The developing units  16   a ,  16   b ,  16   c  and  16   d  correspond to the four colors of yellow, cyan, magenta, and black, respectively. The developing units  16   a ,  16   b ,  16   c  and  16   d  are each configured to include developing rollers that are disposed to oppose the surface of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , stirring rollers for toner stirring, and the like. 
     The toner cartridges  5   a ,  5   b ,  5   c  and  5   d  are provided to correspond to the developing units  16   a ,  16   b ,  16   c  and  16   d , respectively, and store toners of each color supplied to the respective developing units  16   a ,  16   b ,  16   c  and  16   d . The toner cartridges  5   a ,  5   b ,  5   c  and  5   d  store yellow toner, cyan toner, magenta toner, and black toner, respectively. 
     The toner supply parts  6   a ,  6   b ,  6   c  and  6   d  are provided to correspond to the toner cartridges  5   a ,  5   b ,  5   c  and  5   d  and the developing units  16   a ,  16   b ,  16   c  and  16   d , respectively, and supply toner of each color stored in the respective toner cartridges  5   a ,  5   b ,  5   c  and  5   d  to the respective developing units  16   a ,  16   b ,  16   c  and  16   d . The toner supply parts  6   a ,  6   b ,  6   c  and  6   d  are connected with the developing units  16   a ,  16   b ,  16   c  and  16   d , respectively, by toner supply paths that are not illustrated. 
     The toner images of each color formed on the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  are primarily transferred in sequence to the intermediate transfer belt  7 . The intermediate transfer belt  7  is stretched around a driven roller  35 , the counter roller  18  operating as a drive roller, a tension roller  36 , and the like. Since the tension roller  36  biases the intermediate transfer belt  7  from the inside to the outside, a predetermined tension is applied to the intermediate transfer belt  7 . 
     The primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d  are disposed across the intermediate transfer belt  7  from the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  so as to oppose the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. 
     Predetermined portions of the intermediate transfer belt  7  are sandwiched by the primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d  and the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. These sandwiched predetermined portions are pressed against the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. First transfer nips N 1   a , N 1   b , N 1   c  and N 1   d  are formed between the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  and the primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d , respectively. The toner images of each color developed on each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  are primarily transferred in sequence to the intermediate transfer belt  7  at the respective primary transfer nips N 1   a , N 1   b , N 1   c  and N 1   d . A full color toner image is thereby formed on the intermediate transfer belt  7 . 
     A primary transfer bias for causing the toner images of each color formed on the respective photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  to transfer to the intermediate belt  7  is applied to each of the primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d  by a primary transfer bias applying part that is not illustrated. 
     The static eliminators  12   a ,  12   b ,  12   c  and  12   d  are disposed to oppose the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. The static eliminators  12   a ,  12   b ,  12   c  and  12   d  remove electricity (eliminate an electrical charge) from the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively, after the primary transfer has been performed, by irradiating light onto the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d.    
     The drum cleaning parts  11   a ,  11   b ,  11   c  and  11   d  are disposed to oppose the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. The drum cleaning parts  11   a ,  11   b ,  11   c  and  11   d  remove toner and attached matter remaining on the surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively, and make the removed toner, etc. carried to a predetermined collection mechanism for collection. 
     The secondary transfer roller  8  secondarily transfers the full color toner image, which was primarily transferred to the intermediate transfer belt  7 , to the paper T. A secondary transfer bias for causing the full color toner image formed on the intermediate transfer belt  7  to transfer to the paper T is applied to the secondary transfer roller  8  by a secondary transfer bias applying part that is not illustrated. 
     The secondary transfer roller  8  can be either brought into contact with or spaced apart from the intermediate transfer belt  7 . More specifically, the secondary transfer roller  8  is configured to be movable between a contact position that is in contact with the intermediate transfer belt  7  and a spaced position that is spaced apart from the intermediate transfer belt  7 . In particular, the secondary transfer roller  8  is disposed at the contact position in a case of causing the full color toner image primarily transferred to the surface of the intermediate transfer belt  7  to be secondarily transferred to the paper T, and is disposed at the spaced position in other cases. 
     The counter roller  18  is disposed on an opposite side of the intermediate transfer belt  7  than the secondary transfer roller  8 . Predetermined portions of the intermediate transfer belt  7  are sandwiched by the secondary transfer roller  8  and the counter roller  18 . Then, the paper T is pressed against the outer surface (surface to which the toner image is primarily transferred) of the intermediate transfer belt  7 . A secondary transfer nip N 2  is formed between the intermediate transfer belt  7  and the secondary transfer roller  8 . The full color toner image, which was primarily transferred to the intermediate transfer belt  7 , is secondarily transferred to the paper T at the secondary transfer nip N 2 . 
     The fusing portion  9  heats and melts the toner of each color configuring the toner image secondarily transferred to the paper T in order to fuse to the paper T. The fusing portion  9  includes a heated rotating body  9   a  that is heated by a heater, and a pressure rotating body  9   b  that is brought into pressurized contact with the heated rotating body  9   a . The heated rotating body  9   a  and the pressure rotating body  9   b  sandwich, compress, and also feed the paper T secondarily transferred. By the paper T being fed in a state sandwiched between the heated rotating body  9   a  and the pressure rotating body  9   b , the toner transferred to the paper T is fused to the paper T by being melted and pressed. 
     Next, the paper feeding/ejection portion KH will be explained. 
     As shown in  FIG. 1 , two paper feed cassettes  52 , which store the paper T, are disposed to be aligned vertically in a lower portion of the apparatus main body M. The paper feed cassettes  52  are configured to be able to be pulled out from the housing of the apparatus main body M in a horizontal direction. A paper tray  60  on which the paper T are placed is disposed in each of the paper feed cassettes  52 . The paper T is stored in a state of being stacked on the paper tray  60  in the respective paper feed cassettes  52 . The paper T placed on the paper tray  60  is fed to the paper feed path L by the cassette paper feed part  51  disposed at an end (end on left side in  FIG. 1 ) of the paper feed cassette  52  on a paper feeding side. The cassette feed part  51  includes a double feed prevention mechanism consisting of a forward feed roller  61  for picking up paper T on the paper tray  60 , and a feed roller pair  63  for feeding the paper T one at a time to the paper feed path L. 
     The manual paper feed part  64  is provided on a right lateral face (right side in  FIG. 1 ) of the apparatus main body M. The manual paper feed part  64  is provided primarily for the purpose of supplying paper T of differing size and type from the paper T stored in the paper feed cassette  52  to the apparatus main body M. The manual paper feed part  64  includes a manual feed tray  65  constituting a portion of the right lateral face of the apparatus main body M in the closed state, and a paper feed roller  66  serving as a feed roller. The manual paper feed tray  65  functions as a paper tray on which one or a plurality of sheets of the paper T can be placed in the opened state, and has a lower end rotatably mounted (openable and closeable) in a vicinity of the paper feed roller  66 . The paper feed roller  66  sends (feeds) the paper T placed on the manual paper feed tray  65  in the opened state towards the manual feed path La inside of the housing  306 . 
     It should be noted that the feed mechanism  600  for the paper T containing the paper feed roller  66  of the manual paper feed tray  65  will be described later. 
     A first paper ejection part  50   a  and a second paper ejection part  50   b  are provided to an upper side of the apparatus main body M. The first paper ejection part  50   a  and the second paper ejection part  50   b  eject the paper T to outside the apparatus main body M. The details of the first paper ejection part  50   a  and the second paper ejection part  50   b  will be described later. 
     The feed path L feeding the paper T includes: a first paper feed path L 1  from the cassette paper feed part  51  to the second transfer nip N 2 ; a second paper feed path L 2  from the second transfer nip N 2  to the fusing portion  9 ; a third paper feed path L 3  from the fusing portion  9  to the first paper ejection part  50   a ; the manual paper feed path La that guides paper supplied from the manual paper feed part  64  to the first paper feed path L 1 ; a reverse paper feed path Lb that reverses and returns paper fed from the upstream side to the downstream side in the third paper feed path L 3  to the first paper feed path L 1 ; and a post-processing paper feed path Lc that feeds paper fed from the upstream side to the downstream side in the third paper feed path L 3  to a post-processing device (not illustrated) connected to the second paper ejection part  50   b.    
     In addition, a first junction P 1  and a second junction P 2  are provided in the middle of the first paper feed path L 1 . A first branch part Q 1  is provided in the middle of the third paper feed path L 3 . 
     The first junction P 1  is a junction at which the manual paper feed path La converges with the first paper feed path L 1 . The second junction P 2  is a junction at which the reverse paper feed path Lb converges with the first paper feed path L 1 . 
     The first branch part Q 1  is a branching part at which the post-processing paper feed path Lc branches from the third paper feed path L 3 . A dividing member  58  is provided at the first branch part Q 1 . The dividing member  58  causes the feed direction of the paper T fed from the fusing portion  9  to branch (switch between) the third paper feed path L 3  toward the first paper ejection part  50   a  or the post-processing paper feed path Lc toward the second paper ejection part  50   b.    
     A sensor for detecting paper T, and a resist roller pair  80  for skew compensation of the paper T and timing adjustment with respect to the formation of the toner image in the image formation portion GK are disposed in the middle of the first paper feed path L 1  (specifically, between the second junction P 2  and the second transfer roller  8 ) 
     The sensor is disposed directly before the resist roller pair  80  in the feed direction of the paper T (upstream side of the feed direction). The resist roller pair  80  feeds the paper T while performing the aforementioned compensation and timing adjustment based on detection signal information from the sensor. 
     The reverse paper feed path Lb is a feed path provided for making a surface (unprinted surface) opposite to a surface that has already been printed to face toward the intermediate transfer belt  7 , when performing duplex printing on the paper T. According to the reverse paper feed path Lb, paper T fed from the first branch part Q 1  to the first paper ejection part  50   a  side can be reversed and returned to the first paper feed path L 1 , so as to be fed to the upstream side of the resist roller pair  80  disposed on the upstream side of the second transfer roller  8 . At the secondary transfer nip N 2 , a predetermined toner image is transferred to the unprinted surface of the paper T that has been reversed by the reverse paper feed path Lb. 
     The first paper ejection part  50   a  is formed at an end of the third paper feed path L 3 . The first paper ejection part  50   a  is disposed on the upper side of the apparatus main body M. The first paper ejection part  50   a  opens toward the right lateral face side of the apparatus main body M (right side in  FIG. 1 , manual paper feed part  64  side). The first paper ejection part  50   a  ejects the paper T fed through the third paper feed path L 3  to outside of the apparatus main body M. 
     An ejected paper collection part M 1  is formed on the opening side of the first paper ejection part  50   a . The ejected paper collection part M 1  is formed on an upper face (outer face) of the apparatus main body M. The ejected paper collection part M 1  is a portion of the upper face of the apparatus main body M that is formed to be depressed downward. A bottom face of the ejected paper collection part M 1  constitutes a portion of the upper face of the apparatus main body M. Sheets of the paper T on which a predetermined toner image has been formed and is ejected from the first paper ejection part  50   a  are collected by stacking on the ejected paper collection part M 1 . 
     The second paper ejection part  50   b  is formed at an end of the post-processing paper feed path Lc. The second paper ejection part  50   b  is disposed on an upper side of the apparatus main body M. The second paper ejection part  50   b  opens toward a left lateral face side of the apparatus main body M (left side in  FIG. 1 , side at which the post-processing device is connected). The second paper ejection part  50   b  ejects paper T fed through the post-processing feed path Lc to outside the apparatus main body M. 
     A post-processing device (not illustrated) is connected at an opening side of the second paper ejection part  50   b . The post-processing device performs post-processing (stapling, punching, etc.) on paper discharged from the image forming apparatus (copy machine  1 ). 
     It should be noted that a sensor for paper detection is disposed at a predetermined position in each paper feed path. 
     Next, the structure for eliminating a paper jam (JAM) in the main paper feed paths L 1  to L 3  (hereinafter the first paper feed path L 1 , second paper feed path L 2  and third paper feed path L 3  are also collectively referred to as “main paper feed paths”) and the reverse paper feed path Lb will be briefly explained. 
     As shown in  FIG. 1 , the main paper feed paths L 1  to L 3  and the reverse paper feed path Lb are aligned so as to extend primarily in the vertical direction on the left lateral face side of the apparatus main body M (left side in  FIG. 1 ). A cover body  40  is provided to the left lateral face side of the apparatus main body M (left side in  FIG. 1 ) so as to form a portion of the lateral face of the apparatus main body M. The cover body  40  is connected at a lower end thereof to the apparatus main body M via a pivot shaft  43 . The axial direction of the pivot shaft  43  is arranged at a predetermined position along a direction intersecting the main paper feed paths L 1  to L 3  and the reverse paper feed path Lb. The cover body  40  is configured to be pivotable between a closed position (position shown in  FIG. 1 ) and an opened position (not illustrated) about the pivot shaft  43 . 
     The cover body  40  is configured from a first cover part  41  pivotably connected to the apparatus main body M by the pivot shaft  43 , and a second cover part  42  pivotably connected to the apparatus main body M by the same pivot shaft  43 . The first cover part  41  is located more towards the outside (lateral face side) of the apparatus main body M than the second cover part  42 . It should be noted that, in  FIG. 1 , the portion hatched by dashed lines sloped down to the left is the first cover part  41 , and the portion hatched by dashed lines sloped down to the right is the second cover part  42 . 
     In the state in which the cover body  40  is located in the closed position, an outer face side of the first cover part  41  forms a portion of the outer face (lateral face) of the apparatus main body M. 
     In addition, in the state in which the cover body  40  is located in the closed position, the inner face side (apparatus main body M side) of the second cover part  42  forms a portion of the main paper feed paths L 1  to L 3 . 
     Furthermore, in the state in which the cover body  40  is located in the closed position, the inner face side of the first cover part  41  and the outer face side of the second cover part  42  form at least a portion of the reverse paper feed path Lb. In other words, the reverse paper feed path Lb is formed between the first cover part  41  and the second cover part  42 . 
     By providing the cover body  40  of such a configuration, the copy machine  1  of the present embodiment allows for a sheet of paper blocking the main paper feed paths L 1  to L 3  to be handled by pivoting the cover body  40  from the closed position illustrated in  FIG. 1  to the opened position (not illustrated) to open the main paper feed paths L 1  to L 3 , when a paper jam (JAM) occurs in the main paper feed paths L 1  to L 3 . On the other hand, when a paper jam occurs in the reverse paper feed path Lb, a sheet of paper blocking the reverse paper feed path Lb can be handled by causing the second cover part  42  to pivot about the pivot shaft  43  to the apparatus main body M side (right side in  FIG. 1 ) to open the reverse paper feed path Lb, after having pivoted the cover body  40  to the opened position. 
     Next, the configuration relating to the feed mechanism (device)  600  of paper T in the copy machine  1  of the present embodiment will be explained while referring to  FIGS. 2 to 6 . 
       FIG. 2  is a perspective view when the entirety of the feed mechanism  600  is viewed from above at an angle from the right lateral face side of the device main body M.  FIG. 3  is a perspective view when the feed mechanism  600  is viewed from above at an angle from the right lateral face side of the device main body M in a state in which the paper feed roller  66  is removed.  FIG. 4  is a perspective view in which a region in the vicinity of a detection member  621  in  FIG. 3  is enlarged.  FIG. 5  is a perspective view in which a region in the vicinity of the detection member  621  is enlarged in a state where the pad unit  610  is detached in  FIG. 4 .  FIG. 6  is an enlarged perspective view illustrating an installed state of a restricting member  630 . 
     The feed mechanism  600  connects with a lower end of the manual paper feed tray  65  of the manual paper feed part  64  and is disposed inside of the apparatus main body M (refer to  FIG. 1 ). 
     As shown in  FIGS. 2 to 5 , the feed mechanism  600  includes a casing  601 , the paper feed roller (feed roller)  66 , a paper feed drive shaft  605 , the pad unit  610 , the lift plate (ascending/descending member)  603 , a paper supply feed path  640 , a position detection part  620  for paper T, and the restricting member  630 . 
     The casing  601  is disposed on a feed beginning side of the manual paper feed path La in the paper feed path L, which is a downstream side in the feed direction D 1  (refer to  FIGS. 2 and 3 ) of paper T. The casing  601  is fixed to the apparatus main body M. 
     As shown in  FIG. 5 , a mounting part  602  to which the pad unit  610  is mounted is formed in the casing  601 . The mounting part  602  is located substantially in the center of the casing  601  in the orthogonal direction D 3 , and is configured to include a first wall  602   a  abutted (opposed) by the back face of the pad unit  610 , and a horizontal step part  602   b  and second wall part  602   c . The pad unit  610  is detachably mounted to the mounting part  602 . 
     As shown in  FIG. 5 , a recess  601   b  in which the restricting member  630  described later is disposed to be housed is formed in the casing  601 . The recess  601   b  is a narrow concaved part formed by cutting out the horizontal step part  602   b  and the second wall part  602   c  of the mounting part  602 . 
     In addition, a support tube  604  that rotatably supports the paper feed drive shaft  605  is formed in the casing  601 . 
     The paper feed roller  66  is disposed on a downstream side of the casing  601  in the feed direction D 1 . The paper feed roller  66  is disposed so as to be positioned substantially in the center of the casing  601  in the orthogonal direction D 3 . The paper feed roller  66  is disposed to be spaced above the placement surface of the manual paper feed tray  65  and the lift plate  603 . 
     The paper feed roller  66  is disposed to oppose a separation pad member (handle member)  612  of the pad unit  610  described later. The paper feed roller  66  is disposed at an upper side in the vertical direction (above) of the pad unit  610 . 
     The paper feed roller  66  is disposed to oppose (abut) the top face of one or a plurality of sheets of paper T disposed at the feed position (refer to  FIG. 8C , position PS 2 ). The paper feed roller  66  is a paper feed roller (feed roller) that feeds the sheet of paper T on the topmost side among one or a plurality of sheets of paper T disposed at the feed position towards the manual paper feed path La inside the apparatus main body M. 
     The paper feed roller  66  is disposed at the upper side of the casing  601  in the vertical direction to be detachable. 
     The paper feed roller  66  is of substantially columnar form, and is detachably mounted to the paper feed drive shaft  605  that is rotatably retained (supported) to the support tube  604  at both ends in the orthogonal direction D 3 . 
     Herein, the paper feed drive shaft  605  is connected to a drive portion  700  at an end on a side opposite to the paper feed roller  66  either directly or indirectly via a gear member or the like. The paper feed roller  66  is rotationally driven by the rotational drive force output from the drive portion  700 . The rotationally driven paper feed roller  66  feeds (paper feeds) a sheet of paper T disposed to be opposing the paper feed roller  66  inside the apparatus main body M along the paper supply feed path  640  described later. 
     As shown in  FIGS. 2 and 3 , the pad unit  610  is configured to be detachable relative to the mounting part  602  of the casing  601 . 
     In a state mounted to the mounting part  602 , the pad unit  610  is disposed so as to configure a portion of the paper supply feed path  640  described later. In addition, in a state mounted to the mounting part  602 , the pad unit  610  is disposed on a downstream side of the paper T in the feed direction D 1 , below (lower side in the vertical direction) the paper feed roller  66 . 
     The pad unit  610  includes a pad holder  611 , a separation pad member  612  pasted to the pad holder  611 , and a mount holder  613  (refer to  FIG. 8A ) abutted to (placed on) the mounting part  602  of the casing  601 . In addition, a notch portion  619  in which the detection member  621  described later is housed in a state positioned in a retracted position is formed in the pad unit  610 . 
     The mount holder  613  retains the pad holder  611 . The mount holder  613  has a pair of rib parts (not illustrated) formed in both end faces thereof in the orthogonal direction D 3 . The rib parts are formed to be able to insert (engage) into a pair of grooved parts  606  formed at both end sides of the mounting part  602  of the casing  601  in the orthogonal direction D 3 . The pad unit  610  is detachable relative to the mounting part  602  by sliding in the direction in which the groove parts  606  extend, in a state in which the pair of rib parts of the mount holder  613  is inserted (engaged) in the pair of groove parts  606  on the casing  601  side. 
     The pad holder  611  is mounted to the mount holder  613 . The pad holder  611  has a shaft  614  formed at both end faces in a longitudinal direction thereof (orthogonal direction D 3 ). The pad holder  611  is mounted to the mount holder  613  to be rotatable about the shafts  614 , by sticking the pair of shafts  614  into holes (not illustrated) formed in inner faces on both ends of the mount holder  613 . The pad holder  611  is biased so as to pivot in a direction approaching the paper feed roller  66 , by the elastic force (resilience) of a spring that is not illustrated disposed between the pad holder  611  and the mount holder  613 . 
     In addition, separation pad members  612 ,  612  are pasted to the pad holder  611 . 
     The separation pad members  612 ,  612  are pasted to the pad holder  611 . The separation pad members  612 ,  612  are pasted to the pad holder  611 , which is mounted to the mount holder  613 . In the present embodiment, the two separation pad members  612 ,  612  are disposed to be aligned in the orthogonal direction D 3  interposing a portion of the notch portion  619 . The separation pad members  612  are disposed further downstream in the feed direction D 1  than the feed position (position of paper T that can be fed in the feed direction D 1  by the paper feed roller  66 ) to oppose the paper feed roller  66 , in a state in which the pad unit  610  is installed to the casing  601 . 
     The separation pad member  612  is disposed so as to insert, therebetween and the paper feed roller  66 , the paper T. 
     The separation pad member  612  is biased so as to pivot in a direction to contact the paper feed roller  66  (or paper T), by the elastic force (resilience) of a spring via the pad holder  611 . 
     The separation pad member  612  contacts or moves away from the paper feed roller  66  (or paper T) by the pad holder  611  pivoting relative to the casing  601  (apparatus main body M) about the shafts  614 . 
     The notch portion  619  is a portion in which the detection member  621  positioned in the retracted position is housed. 
     The notch portion  619  is a concave portion that is formed to span the pad holder  611  and the mount holder  613 . The notch portion  619  is formed at a position opposing the detection member  621 . The notch portion  619  is formed in a size and shape that allows the detection member  621  positioned in the retracted position to be housed therein. 
     The lift plate  603  (ascending/descending member) is disposed at a lower side in the vertical direction (below) of the paper feed roller  66 . The lift plate  603  is a flat member that causes a sheet of paper T placed on a paper feed setup position of the manual paper feed tray  65  to contact or separate from the paper feed roller  66 . The lift plate  603  is a member that presses a sheet of paper T disposed at the paper feed setup position to the paper feed roller  66  or releases pressing by moving up or down relative (toward) the paper feed roller  66  by way of a lift drive portion that is not illustrated. 
     The paper supply feed path  640  is a paper feed path in which paper T placed on the placement surface of the manual paper feed tray  65  is fed to inside of the apparatus main body M. 
     The paper supply feed path  640  includes an upper space of the placement surface of the manual paper feed tray  65  further upstream in the feed direction D 1  than the upper surface of the lift plate  603 . The paper supply feed path  640  is a paper feed path in which paper T is fed from the upper space of the placement surface of the manual paper feed tray  65 , past the upper surface of the lift plate  603  and the upper surface of the separation pad member  612 , until an opening part of the manual paper feed path La inside of the apparatus main body M. 
     In the present embodiment, the paper supply feed path  640  refers to a paper feed path in which paper T fed by the paper feed roller  66  is fed in a state in which the lift plate  603  is raised (state in which topmost face of the paper T abuts the paper feed roller  66 ). 
     The position detection part  620  has a detection member  621 , a switch part  622 , and a detector  623  that is a functional part of a CPU  740  described later. 
     The position detection part  620  is a position detector that detects the presence of paper T on the manual paper feed tray  65 . 
     More specifically, the position detection part  620  is a position detector that detects the fact that one or a plurality of sheets of the paper T has been placed at a predetermined position on the manual paper feed tray  65 . 
     In detail, the position detection part  620  is a position detector that detects whether a sheet of paper T (leading end) placed on the manual paper feed tray  65  is disposed at a feed position that can be fed by the paper feed roller  66 , or whether a sheet of paper T is disposed at a feed setup position (refer to  FIG. 8B , position PS 1 ) that is near the feed position and is for moving the paper T to the feed position by a predetermined ascending/descending member (the lift plate  603  in the present embodiment). 
     In addition, the position detection part  620  is a position detector that detects the detection member  621  being positioned at the retracted position. The position detection part  620  is a position detector that detects the detection member  621  being positioned at an initial position, or positioned at the retracted position. 
     The position detection part  620  detects a sheet of paper T being positioned at the feed position or feed setup position in a case of the detection member  621  being positioned at the retracted position. In other words, the position detection part  620  does not detect a sheet of paper T being positioned at the feed position or feed setup position in a case of not detecting the detection member  621  being positioned at the retracted position (detects that a sheet of paper T is not at the feed position or feed setup position). 
     The detection member  621  is disposed more on an upstream side of the pad unit  610  in the feed direction D 1  than the separation pad member  612 . 
     The detection member  621  is disposed to oppose the pad unit  610  in a state in which the pad unit  610  is installed. 
     The detection member  621  has a pair of rotating shafts  624 ,  624  formed so as to protrude outwards in the orthogonal direction D 3  at the lower end side in the vertical direction. The detection member  621  is pivotably mounted to the casing  601  by the rotating shafts  624 ,  624 . 
     The detection member  621  is configured to be movable between the initial position (refer to  FIG. 8A ) and the retracted position (refer to  FIG. 8C ). 
     The initial position is a position that is abutted to a leading end of a sheet of paper T when the paper T is moved from a predetermined placement position in a state placed on the manual paper feed tray  65  to the feed position or feed setup position on the lift plate  603  side. 
     In the present embodiment, the paper T is moved from the predetermined position to the feed setup position in a case of being placed on the manual paper feed tray  65 , and then moved from the feed setup position to the feed position. In the present embodiment, the initial position is a position at which the leading end of the paper T is abutted in a case of paper placed on the manual paper feed tray  65  being moved from the predetermined position to the feed setup position. 
     In the present embodiment, the detection member  621  disposed at the initial position is arranged (at an attitude extending in the vertical direction) so as to project through the notch portion  603   a  formed at a leading end of the lift plate  603  and block a portion of the paper supply feed path  640  (refer to  FIGS. 4 ,  5  and  8 A). 
     In a state in which the paper T is disposed at the feed position or feed setup position, the retracted position is a position at which the detection member  621  does not abut the leading end of a topmost sheet of paper T fed by the paper feed roller  66 . The retracted position is a position in which the detection member  621  does not restrict the feeding movement of the paper T fed by the paper feed roller  66 . The retracted position is a position that does not block the paper supply feed path  640 . The retracted position is a position retracted from the placement portion in a state in which the at least one paper T is disposed at the feed position or the feed setup position. 
     In the present embodiment, the detection member  621  positioned in the retracted position is housed in the aforementioned notch portion  619 . The detection member  621  is pivotally moved from the initial position to the retracted position, which is the position housed in the notch portion  619 . The detection member  621  is configured so as to be housed in the notch portion  619  and retract from the paper supply feed path  640  in a case of being moved from the initial position to the retracted position by the paper T. 
     The detection member  621  disposed in the retracted position is positioned to be retracted from the paper supply feed path  640 , which is formed in a state in which the lift plate  603  is raised. 
     The switch part  622  outputs a predetermined signal to the CPU  740  (detector  623 ) described later, according to the position of the detection member  621 . The switch part  622  outputs a predetermined signal to the CPU  740  (detector  623 ) when the detection member  621  is positioned at the retracted position, for example. The switch part  622  is disposed in the vicinity of the detect member  621 , for example. 
     The detector  623  detects whether the detection member  621  is moving (positioned) to the retracted position. The detector  623  detects whether the detection member  621  is moving (positioned) to the retracted position by receiving a signal output from the switch part  622 , for example. 
     The detector  623  detects (recognizes) that a plurality of sheets of paper T have been placed at the predetermined position of the manual paper feed tray  65 , in a case of having detected that the detection member  621  is moving (positioned) to the retracted position. The detector  623  detects (recognizes) that the paper T is disposed at the feed position or feed setup position, in a case of having detected that the detection member  621  is moving (positioned) to the retracted position. 
     Then, the detector  623  outputs a predetermined signal to a drive controller  710  described later, in a case of having detected that detection member  621  moving (positioned) to the retracted position. 
     Herein, the drive controller  710  described later permits the drive portion  700  to enter a drivable state in a case of having received the predetermined signal from the detector  623 . As a result, the paper feed roller  66  is not rotationally driven in a case of the detection member  621  not having been detected to be moving (positioned) to the retracted position by the detector  623 . 
     As shown in  FIGS. 5 and 6 , the restricting member  630  is disposed to be storable in the concaved recess (stored position)  601   b  formed in the casing  601 . 
     As shown in  FIG. 8A , in a state in which the pad unit  610  is installed to the mounting part  602  of the casing  601 , the restricting member  630  is disposed at a position opposing the detection member  621 , interposing the pad unit  610 . 
     As shown in  FIG. 6 , the restricting member  630  is pivotally supported around a support shaft  631  at a base end  630   a  thereof. The restricting member  630  is biased so as to pivotally move to a restricting position side described later, by the elastic force of a helicoidal spring (example of a biasing member)  632  wound around a portion of the support shaft  631 . 
     The restricting member  630  is configured to be pivotally movable between a stored position (restriction release position, refer to  FIG. 4 ), and a restricting position (refer to  FIG. 5 ). 
     More specifically, the restricting member  630  is configured to be pivotally movable between a stored position (restriction release position, refer to  FIG. 4 ) at which the pad unit  610  is positioned in an installed state installed to the mounting part  602 , and a restricting position (refer to  FIG. 5 ) at which the pad unit  610  is positioned in a detached state detached from the mounting part  602 . 
     In particular, the restricting member  630  is configured to be pivotally movable between a stored position (restriction release position, refer to  FIG. 4 ) separated from the detection member  621  and allowing pivotal movement of the detection member  621  from the initial position to the retracted position, in an installed state in which the pad unit  610  is installed to the mounting part  602 , and a restricting position (refer to  FIG. 5 ) project to stand at a substantially level attitude (attitude extending in the horizontal direction in  FIG. 5 ), the leading end  603   b  abutting the detection member  621  (as a prop), and restricting pivotal movement of the detection member  621  from the initial position to the retracted position, in a detached state in which the pad unit  610  is detached from the mounting part  602 . 
     It should be noted that the restricting member  630  may restrict such that the detection member  621  entirely cannot move from the initial position in a state abutting the detection member  621 , or may restrict such that the detection member  621  moves slightly in the retracted position direction in a range that can catch the paper T. 
     Next, focusing on the feed mechanism  600 , the configuration of the control system of the copy machine  1  will be explained while referring to  FIG. 7 .  FIG. 7  is a block diagram illustrating the configuration of the control system of the copy machine  1 . 
     As shown in  FIG. 7 , the copy machine  1  includes the paper feed roller  66 , the drive portion  700  causing the paper feed roller  66  to rotationally drive, the detection member  621  and switch part  622  configuring the position detection part  620 , the CPU  740 , an image data receiving part  720 , and the image forming portion GK. 
     The CPU  740  includes the detector  623  configuring the position detection part  620 , the drive controller  710 , and an image formation controller  730 . 
     The drive portion  700  is a motor, and the like, that is connected to the paper feed roller  66  via the paper feed drive shaft  605 , and rotationally drives the paper feed roller  66 . The drive portion  700  is controlled by the drive controller  710 . 
     The drive controller  710  controls the drive portion  700  so as to permit the drive portion  700  to rotationally drive in a state in which the detector  623  (position detection part  620 ) is detecting that the paper T is disposed at a predetermined feed position or the feed setup position, and so as not to permit the drive portion  700  to rotationally drive in a state in which the detector  623  (position detection part  620 ) has not detected that the paper T is disposed at the predetermined feed position or feed setup position. 
     In a state in which a predetermined signal indicating that the detection member  621  is positioned at the retracted position is received from the detector  623  (position detection part  620 ), the drive controller  710  permits the drive portion  700  to rotationally drive in a case of a signal requesting the driving of the drive portion  700  being received from the image formation controller  730  described later (outputs a drive signal to the drive portion  700 ). 
     In addition, in a state in which a predetermined signal indicating that the detection member  621  is positioned at the retracted position is not received from the detector  623  (position detection part  620 ) (or in a state in which a predetermined signal indicating that the detection member  623  is at the initial position), the drive controller  710  does not permit the drive portion  700  to rotationally drive in a case of a signal requesting driving of the drive portion  700  being received from the image formation controller  730  described later (does not output a drive signal to the drive portion  700 ). 
     The image data receiving part  720  receives image data read by the image reading device  300 . Herein, image data includes an image formation instruction that is an instruction to the image formation portion GK to form predetermined toner images on the respective photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , image information related to a toner image, paper number information, and the like. 
     The image formation controller  730  controls the image forming portion GK so as to cause toner images to be formed on the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively. The image formation controller  730  outputs an image formation instruction to the image forming portion GK so as to cause toner images to be formed on the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , respectively, in a case of image data being received by the image data receiving part  720 . 
     In addition, the image formation controller  730  outputs a signal requesting driving of the drive portion  700  to the drive controller  710 , in a case of image data being received by the image data receiving part  720 . 
     Next, operations of the copy machine  1  of the present embodiment will be briefly explained. 
     First, a sheet of paper T stored in the paper feed cassette  52  is fed to the first paper feed path L 1  by the forward feed roller  61  and a feed roller pair  63 , and subsequently, is fed to the resist roller pair  80  via the first junction P 1  and the second paper feed path L 2 . 
     Skew correction of the paper T and timing adjustment with the toner image is performed at the resist roller pair  80 . 
     The paper T sent from the resist roller pair  80  is introduced to the second transfer nip N 2  between the intermediate transfer belt  7  and the second transfer roller  8  via the first paper feed path L 1 . Then, a toner image is transferred to the paper T between the intermediate transfer belt  7  and the second transfer roller  8 . 
     Subsequently, the paper T is sent out from between the intermediate transfer belt  7  and the second transfer roller  8 , and is introduced to between the heated rotating body  9   a  and the pressure rotating body  9   b  of the fusing portion  9 , via the second paper feed path L 2 . Then, by the paper T being fed in a state sandwiched between the heated rotating body  9   a  and the pressure rotating body  9   b , the toner transferred to the paper T is fused to the paper T by being heated and pressed thereby. 
     Next, the paper T is fed to the first paper ejection part  50   a  or second paper ejection part  50   b  via the third paper feed path L 3 , and is discharged to the ejected paper collection part M 1  or outside of the apparatus main body M. 
     By performing operations in this way, printing of the paper T stored in the paper feed cassette  52  is completed. 
     In a case of printing on paper T placed on the manual paper feed tray  65 , the paper T placed on the manual paper feed tray  65  is fed to the manual paper feed path La by the paper feed roller  66  (feed mechanism  600 ), and subsequently is fed to the resist roller pair  80  via the first junction P 1  and the first paper feed path L 1 . The operations from then on are similar to the aforementioned operations of one-sided printing of a sheet of paper T stored in the paper feed cassette  52 , and thus an explanation thereof will be omitted. 
     Herein, operations of the feed mechanism  600  that feeds paper T placed on the manual paper feed tray  65  into the apparatus main body M will be described in detail hereafter. 
     Next, operations of the feed mechanism  600  of paper T in the copy machine  1  of the present embodiment will be explained while referred to  FIGS. 8A to 8E . 
       FIG. 8A  is a view illustrating a state in which the pad unit  610  is mounted to the mounting part  602  of the casing  601 .  FIG. 8B  is a view illustrating a state in which the paper T is moved from the state in  FIG. 8A  in the arrow F 1  direction and the detection member  621  pivotally moves.  FIG. 8C  is a view illustrating a state in which the lift plate  603  rises from the state in  FIG. 8B .  FIG. 8D  is a view illustrating a state in which the pad unit  610  is made to move in the arrow F 4  direction after the paper feed roller  66  has been removed. FIG. BE is a view illustrating a state in which the pad unit  610  is made to move further in the arrow F 4  direction from the state in  FIG. 8D  to be detached from the mounting part  602 . 
     First, in the state in which the pad unit  610  is mounted to the mounting part  602 , as shown in  FIG. 8A , the restricting member  630  is pressed to the pad unit  610  and is disposed to be housed inside of the recess  601   b . In other words, the restricting member  630  separates from the detection member  621  of the position detection part  620  to be disposed in the restriction release position which permits pivotal movement of the detection member  621  from the initial position to the retracted position. 
     Next, when a sheet of paper T is made to move so as to insert in the arrow F 1  direction accompanying the user placing a plurality of sheets of paper T on the placement surface of the manual paper feed tray  65  as shown in  FIG. 8B , the detection member  621  disposed at the initial position is pivotally moved in the arrow F 2  direction in a state abutted at a leading end of the paper T. Then, in a state in which the paper T is disposed at the feed setup position PS 1 , the detection member  621  is pivotally moved from the initial position to the retracted position. 
     Upon the detection member  621  being pivotally moved to the retracted position, the switch part  622  outputs a predetermined signal to the CPU  740  (detector  623 ). Then, upon receiving the predetermined signal from the switch part  622 , the detector  623  outputs to the drive controller  710  a signal indicating that the detection member  621  is at the retracted position. The drive controller  710  having received this signal enters a state in which driving of the drive portion  700  is permissible. 
     In other words, in this state, the drive controller  710  outputs to the drive portion  700  a drive signal instructing to drive, in a case of having received from the image formation controller  730  a signal requesting to make the drive portion  700  driven. 
     In addition, the drive controller  710  similarly controls a lift drive portion (not illustrated) that drives the lift plate  603  to ascend or descend. In a state of receiving from the detector  623  a predetermined signal indicating that the detection member  621  is positioned at the retracted position, the drive controller  710  permits the lift drive portion to drive to ascend or descend in a case of having received from the image formation controller  730  described later a signal requesting the driving of the lift drive portion (outputs a lift drive signal to the lift drive portion). 
     By doing this, the lift plate  603  is ascendingly moved, as shown in  FIG. 8C , and a leading end of a sheet of paper T not illustrated is disposed at the feed position PS 2 . 
     In addition, the paper T is thereby fed to the paper supply feed path  640  while double feeding is suppressed by being inserted between the paper feed roller  66  and the separation pad member  612  of the pad unit  610 , and the paper T is fed to the manual paper feed path La inside of the apparatus main body M. 
     Then, in a case of the paper feed roller  66 , the pad unit  610 , etc. wearing and deteriorating, and it becoming necessary to replace with a new part or repair, the user can detach the pad unit  610  from the mounting part  602  of the casing  601  by removing the paper feed roller  66  to above the casing  601 , and then causing the pad unit  610  to slide upwards through the space created by removing the paper feed roller  66 . 
     First, when the pad unit  610  is made to move in the arrow F 4  direction after having removed the paper feed roller  66  from the casing  1 , as shown in  FIG. 8D , the restricting member  630  is pivotally moved gradually upwards around the support shaft  631  by the biasing force of the helicoidal spring  632 . The restricting member  630  is pivotally moved from the stored position to the restricting position side. 
     Then, in a state in which the pad unit  610  has been completely detached from the mounting part  602  of the casing  601  by moving in the arrow F 4  direction, as shown in  FIG. 8E , the restricting member  630  projects to stand at a substantially horizontal attitude, and is moved to the restricting position which is a position in which the leading end  630   b  thereof abuts the detection member  621  of the position detection part  620 , and restricts the detection member  621  from pivotally moving from the initial position to the retracted position. 
     The detection member  621  of the position detection part  620  thereby comes to be maintained at a position such that a portion of the paper supply feed path  640  is blocked. 
     In other words, in the state shown in  FIG. 8E , the detection member  621  restricts movement of paper T to the downstream side in the feed direction D 1 . The detection member  621 , for which movement to the retracted position is restricted by the restricting member  630 , restricts the paper T from being disposed (moved) to the feed position or feed setup position. 
     From a structural perspective, it is thereby possible to suppress paper T from becoming stacked and fed inside of the apparatus main body M (occurring by the pad unit  610  not being mounted), even in a case of the paper feed roller  66  being mounted in the state in which the pad unit  610  has been removed shown in  FIG. 8E . 
     In addition, the detection member  621  is restricted from moving from the initial position to the retracted position, as explained above. In other words, in this state, the drive controller  710  is maintained in a state not permitting the drive portion  700  to drive. 
     From a control aspect, it is thereby possible to suppress the paper T from becoming stacked and fed inside of the apparatus main body M, even in a case of the paper feed roller  66  being mounted in a state in which the pad unit  610  has been removed shown in  FIG. 8E . 
     Therefore, the feed mechanism  600  can suppress (prevent) malfunction such as a severe paper jam occurring due to the paper feed roller  66  being rotationally driven and the paper T being fed, even if the pad unit  610  is not mounted or one forgets to mount the pad unit  610  after replacement or repair. 
     Next, referring to  FIG. 9 , operations for suppressing the occurrence of malfunctions such as double feed and paper jams in a case of having forgotten to mount a new pad unit  610  to the mounting part  602  of the casing  601  after replacement or repair will be explained focusing on the operations of the control system of the copy machine  1  shown in  FIG. 7 .  FIG. 9  is a flowchart illustrating operations of the control system of the copy machine  1 . 
     First, a user removes the old pad unit from the mounting part  602 , and then mounts the paper feed roller  66  to the casing  601  without installing the new pad unit. 
     Then, in Step ST 101 , the user operates a power source operation part, which is not illustrated, to turn ON the power source of the copy machine  1 . 
     Continuing, in Step ST 102 , the image data receiving part  720  receives image data read by the image reading device  300 . The image data includes an image formation instruction that is an instruction to the image forming portion GK to form predetermined toner images on the respective photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d , image information related to a toner image, paper number information, and the like. 
     Then, in Step ST 103 , the image formation controller  730  receives image data output from the image data receiving part  720 . 
     Next, in Step ST 104 , the image formation controller  730  outputs a signal instructing image formation to the image forming portion GK, and outputs a request signal requesting to the drive controller  710  to cause the drive portion  700  to rotationally drive. 
     Subsequently, in Step ST 105 , the position detection part  620  (detector  623 ) confirms whether it is being detected that the detection member  621  is in the retracted position. 
     In this case, the detection member  621  of the position detection part  620  is in a state in which pivotally moving from the initial position to the retracted position is restricted by contact with the restricting member  630 , as shown in  FIG. 8E ; therefore, the position detection part  620  (detector  623 ) does not detect that the detection member  621  is at the retracted position. 
     The drive controller  710  thereby does not permit the drive portion  700  to rotationally drive the paper feed roller  66 . 
     Therefore, the paper T is not forcibly fed to the manual paper feed path La inside of the apparatus main body M through the paper supply feed path  640 , and thus a malfunction such as a severe paper jam from paper T being fed while one has forgotten to mount the pad unit  610  is suppressed from occurring. 
     Then, in this case (Step ST 105 , NO), the processing is returned to before Step ST 104 . Herein, it may be configured so as to notify by way of a notification unit (not illustrated) that the pad unit  610  is not installed, in a case of the processing returning to Step ST 104  being repeated a predetermined number of times. 
     A user having received the determination results of Step ST 105  (NO) and having realized having forgotten to mount the pad unit  610  installs the pad unit  610  to the mounting part  602 . When the pad unit  610  is installed to a predetermined mounting part  602 , the restricting member  630  is moved to the restriction release position, as shown in  FIG. 8A . According to this, the detection member  621  of the position detection part  620  enters a state in which pivotal movement from the initial position to the retracted position is allowed. 
     When the leading end of the paper T placed on the placement surface of the manual paper feed tray  65  abuts the detection member  621  and is made to move so as to abut and press the detection member  621  in this state, the detection member  621  is pivotally moved from the initial position to the retracted position. 
     The position detection part  620  (detector  623 ) thereby detects that the detection member  621  is at the retracted position (Step ST 105 , YES). Then, the processing advances to Step ST 106 . 
     Subsequently, in Step ST 106 , the drive controller  710  permits the drive portion  700  to rotationally drive the paper feed roller  66  (similarly permits ascending and descending driving of the lift drive portion (not illustrated)); therefore, the paper T (is transferred from the feed setup position to the feed position) is fed to the paper supply feed path  640  in a state in which double feeding is suppressed by being inserted between the paper feed roller  66  and the separation pad member  612  of the pad unit  610 , and is fed to the manual paper feed path La inside of the apparatus main body M. 
     The paper T fed in the manual paper feed path La is fed to the resist roller pair  80  via the first junction P 1  and the first paper feed path L 1 . From then on, image formation operations (printing) similar to those previously described are performed. 
     Next, in Step ST 107 , the image formation controller confirms whether image formation operations (printing) of a predetermined number of sheets of paper received from the image data receiving part  720  have completed. The image formation controller continues the processing in a case of not confirming that image formation operations of a predetermined number of sheets of paper has completed (NO), and ends the processing in a case of having confirmed that image formation operations of a predetermined number of sheets of paper has completed (YES). 
     The following effects are exerted according to the copy machine  1  of the present embodiment, for example. 
     The copy machine  1  of the present embodiment includes: the paper feed roller  66  that feeds the paper T placed on the manual paper feed tray  65  to inside of the apparatus main body M; the paper supply feed path  640  for paper T; the pad unit  610  that is disposed at a predetermined mounting part  602  so as to configure a portion of the paper feed supply path  640  and is detachable relative to the mounting part  602 , is disposed to oppose the paper feed roller  66  further downstream in the feed direction in which the paper T is fed than the predetermined feed position, and has the separation pad members  612  disposed so as to sandwich, therebetween and the paper feed roller  66 , the paper T; the position detection part  620  including the detection member  621  that is configured to be moveable between an initial position which is a position abutted to the leading end of the paper T moved, in a case of the paper T being moved from the predetermined position to the feed position or feed setup position, and a retracted position which is a position not abutted to the leading end of the topmost sheet of paper T, in a state disposed in the feed position, the switch part  622  that detects whether the detection member  621  is positioned at the retracted position, and detects that the paper T is disposed at the feed position or feed setup position in a case of having detected that the detection member  621  is at the retracted position; and the restricting member  630  that is disposed in the stored position opposing the detection member  621  to sandwich, therebetween and the detection member  621 , the pad unit  610  in an installed state in which the pad unit  610  is installed to the mounting part  602 , and is disposed at a restricting position that restricts the detection member  621  from moving from the initial position to the retracted position by abutting the detection member  621 , in a detached state in which the pad unit  610  is detached from the mounting part  602 . 
     As a result, in a state in which the pad unit  610  is detached from a predetermined mounting part  602  for replacement or repair, it is possible for the restricting member  630  to abut the detection member  621  and restrict movement of the detection member  621  from the initial position at which the leading end of the paper T is abutted to the retracted position at which the leading end of the paper T is not abutted. Therefore, it is possible to suppress a malfunction such as a severe paper jam from occurring accompanying the paper T being forcibly fed while one has forgotten to install the pad unit  610 , by making it so that the feed of paper T by the rotational driving of the paper feed roller  66  does not occur in a case of having forgotten to mount the pad unit  610  detached for replacement or repair back to a predetermined mounting part  602  after the replacement or repair. In addition, the causes for failure of the image forming apparatus can also be drastically reduced. 
     Furthermore, in the present embodiment, the spring  632  is included that biases the restricting member  630  towards the restricting position, i.e. a position abutting the detection member  621  of the position detection part  620 . 
     As a result, in a case of the pad unit  610  being detached from the mounting part  602 , the restricting member  630  can be made to automatically move to the restricting position by the biasing force of the spring  632 . Therefore, the labor in causing the restricting member  630  to move to the restricting position by hand after detachment of the pad unit  610  can be eliminated, and forgetting to move the restricting member  630  to the restricting position can be prevented. As a result, the occurrence of malfunctions such as a severe paper jam accompanying paper T being forcibly fed while one has forgotten to install the pad unit  610  can be much more reliably suppressed. 
     Furthermore, in the present embodiment, the copy machine  1  includes the drive portion  700  that causes the paper feed roller  66  to be rotationally driven, and the drive controller  710  that controls the drive portion  700 . In addition, the drive control  710  is a controller that can permit the drive portion  700  to rotationally drive in a state in which the position detection part  620  detects that a sheet of paper T is disposed at a predetermined feed position or feed setup position, and does not permit the drive portion  700  to rotationally drive in a state in which the position detection part  620  does not detect that a sheet of paper T is disposed at the predetermined feed position or feed setup position. Then, in a case of the pad unit  610  being in a detached state, it is not detected by the position detection part  620  that a sheet of paper T is disposed at the feed position or feed setup position due to movement of the detection member  621  to the retracted position being restricted by the restricting member  630 , and thus the drive controller  710  does not permit the drive portion  700  to rotationally drive. 
     As a result, it is possible to perform feed operation control of paper in that movement of the detection member  621  to the retracted position is not only mechanically restricted in a case of the pad unit  610  being in a state detached from the mounting part  602  as when forgetting installation of the pad unit  610 , but also rotational driving of the drive portion  700  is not permitted based on the detection signal of the position detection part  620 . Therefore, the feed mechanism  600  can reliably suppress forcible feeding of paper T when forgetting to install the pad unit  610  and the occurrence of malfunctions such as a severe paper jam accompanying this by mechanical (structural) restriction and control restriction. 
     Although a preferred embodiment of the present invention has been explained above, the present invention is not to be limited to the aforementioned embodiment, and various modifications thereto can be carried out. 
     For example, in the embodiment, the feed mechanism  600  is applied to the feed of the manual paper feed tray  65 ; however, it is not limited thereto. For example, the feed mechanism  600  may be applied to the feed of the paper feed cassette  52 . 
     In addition, in the embodiment, it is configured such that both the detection member  621  of the position detection part  620  and the restricting member  630  move spatially by pivoting; however, they are not limited thereto. For example, the detection member  621  may be configured to be able to move between the initial position and the retracted position by sliding vertically, and the restricting member may be configured to be able to move between the restricting position and the restriction release position by sliding substantially horizontally. 
     In addition, in the embodiment, an explanation has been provided in which the separation pad member is given as an example of a separation member; however, it is not limited thereto. For example, the separation member may be a separation roller or the like. Furthermore, in the embodiment, an explanation has been similarly provided in which the pad unit is given as an example of a separation unit; however, it is not limited thereto. For example, the separation unit may be a separation roller unit having a separation roller. 
     In addition, in the embodiment, although an explanation has been provided in which the copy machine  1  is given as an example of an image forming apparatus, the image forming apparatus may be a monochromatic copy machine, a printer, a facsimile, a multifunctional machine with these functions, or the like. 
     Moreover, the image formation target material is not limited to paper, and may be a film sheet, for example.