Patent Publication Number: US-7722032-B2

Title: Sheet feeding device and image forming apparatus

Description:
FIELD OF THE INVENTION 
   The present invention relates to a sheet feeding device and an image forming apparatus provided with the sheet feeding device, wherein image forming at a predetermined position of a sheet is achieved in a light printing process or the like, overcoming the problem of angle deviation of the sheet. 
   BACKGROUND OF THE INVENTION 
   For example, it is known to use an electrophotographic image forming apparatus, such as a copier, printer or facsimile machine, form images on the front and back sides of sheets, and bind a bundle of the sheets to produce a book. In the case of using an image forming apparatus in such a manner, highly accurate positioning of an image on a sheet is required. In other words, high quality image forming free from position deviation of images on the front and back sides of a sheet is required. Further, in the case of cutting the edge portions of plural sheets after binding, images may be partially cut off to be missing if the positions of edge portions of formed images are not correctly aligned. 
   In general, a sheet feeding device is provided with regulating members to regulate the sides of sheets stored in a sheet feeding tray, along the transverse direction. When regulating members are accurately collided with sheets for regulation, almost no shift or angle deviation of sheets is caused. However, as disclosed in Japanese Unexamined Patent Application Tokkaihei No. H05-132240, an image forming apparatus is, in general, provided with a plurality of sheet feeding devices, having a sheet loading table, for respective sizes of sheets, wherein when an opening and closing cover arranged on a sheet feeding device is opened, or when a sheet feeding tray is drawn out from the main body of a sheet feeding device, a sheet loading table with sheets stacked thereon is automatically falls to a lower position so that sheets can be supplied. Therefore, even when adjusting the position of regulating members, adjustment is carried out in a state where a sheet loading table has been lowered to a lower position. However, even trying to regulate sheets in the transverse direction in a state where a sheet loading table has been lowered to a lower position, the sheets are not at the sheet feeding position, but are below and too far from the sheet feeding position, which makes regulation in the transverse direction incorrect and cannot achieve a high accuracy. 
   That is, regulating members may be deformed depending on the accuracy of manufacturing, change with time, etc., and accordingly the distance between regulating members deviates between an upper position where sheets are actually fed and a lower position to which a sheet loading table has been lowered. Consequently, even adjusting regulating members correctly at a lower position to which a sheet loading table has been lowered, when sheets have risen to a position for actual sheet feeding thereafter, a gap may be created along the transverse direction between the side of the sheets and a regulating member to cause angel deviation of the sheets, prohibiting accurate regulation of the position of the sheets. Herein, angle deviation of sheets means a state where sheets are located not parallel to the sheet conveying direction, and have an angle deviation to the conveying direction. 
   Particularly, the angle deviation is significant in a large capacity tray (LCT) with a large rise and fall amount of a sheet loading table. 
   For solution of problems, as described above, and adjustment of regulating members that is sufficiently accurate, it is necessary that sheets are held at a sheet feeding position at the time of adjustment. Herein, the adjustment can be made by an input via an operation unit, by opening an opening and closing cover of a sheet feeding device, or by drawing out a sheet feeding tray. On the other hand, when supplying sheets, it is necessary that a sheet loading table falls and then sheets can be supplied. An object of the invention is to provide a sheet feeding device that can feed a sheet at a highly accurate position by adjusting the positions of regulating members with a simple mechanism and an image forming apparatus provided with such a sheet feeding device. 
   SUMMARY OF THE INVENTION 
   The invention includes the following structures. 
   (1) A sheet feeding device, including: 
   a sheet loading table; 
   a sheet feeding member that feeds a sheet from an uppermost portion of sheets stacked on the sheet loading table; 
   a regulating member that regulates a side of sheets, in a transverse direction orthogonal to a sheet feeding direction; 
   an opening and closing mechanism that opens and closes a sheet feeding section; 
   a lowering mechanism that lowers the sheet loading table that holds sheets at a sheet feeding position, to a lower position by opening the opening and closing mechanism; 
   an adjusting mechanism that adjusts a position of the regulating member in the transverse direction; and 
   a holding mechanism that holds a position of the sheet loading table so as to hold the sheets at the sheet feeding position even when the opening and closing mechanism is opened. 
   (2) An image forming apparatus, including the sheet feeding device of above item (1) and an image forming unit that forms an image. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional structural view of an image forming apparatus provided with a sheet feeding device as an example of an embodiment in accordance with the invention; 
       FIG. 2  is a perspective view of a sheet feeding section in a state where an opening and closing cover F is removed from a large capacity tray LCT; 
       FIG. 3  is a block diagram of a control device A of an image forming apparatus provided with a sheet feeding device in accordance with the invention; 
       FIG. 4  is a flowchart of a control of lifting and lowering of a sheet loading table  20   a  in accordance with the invention; 
       FIG. 5  is a perspective view showing a state where a sheet feeding tray  101  is drawn out from a main body frame  100 B of the sheet feeding device; 
       FIGS. 6   a  and  6   b  are a front view and side view of the sheet feeding tray  101  in a state where sheets are at a sheet feeding position, and  FIGS. 6   c  and  6   d  are a front view and side view of the sheet feeding tray  101  in a state where sheets are supplied onto a sheet loading table; and 
       FIG. 7   a  is a detailed diagram of part A in  FIG. 6   a , and  FIG. 7   b  is a detailed diagram of part C in  FIG. 6   c.    
   

   PREFERRED EMBODIMENTS OF THE INVENTION 
   Embodiment 1 
   An embodiment in accordance with the invention will be described below, referring to the drawings. 
   Herein, the description of the present embodiment does not limit the scope of the invention. 
   Regarding X, Y and Z directions shown in the respective figures, X direction represents the left direction when an image forming apparatus in the present embodiment is viewed from the front, and Reverse X direction represents the right direction. Y direction represents the up direction when the apparatus is viewed from the front, and Reverse Y direction represents the down direction. Z direction represents the depth direction when the apparatus is viewed from the front, and Reverse Z direction represents the front direction. 
     FIG. 1  is a cross-sectional structural view of an image forming apparatus provided with a sheet feeding device as an example of embodiment in accordance with the invention. This image forming apparatus is called a tandem type color image forming apparatus including a plurality of image forming units  10 Y,  10 M,  10 C and  10 K, an intermediate transfer unit  7 , a fixing device  24  and the sheet feeding device. An image reading device SC is disposed at the top portion of an image forming device main body GH. As an example of a sheet feeding device in accordance with the invention, a large capacity tray (LCT) in the present embodiment is arranged on the right side, in  FIG. 1 , of the image forming device main body GH. Sheets are supplied from the large capacity tray LCT, sheet feeding trays  20  or a manual sheet feeding tray C. 
   The image forming unit  10 Y for forming yellow colored images includes a charging unit  2 Y, exposing unit  3 Y, developing unit  4 Y, primary transfer roller  5 Y as a primary transfer unit, and cleaning unit  6 Y which are disposed around a photoreceptor  1 Y. The image forming unit  10 M for forming magenta colored images includes a photoreceptor  1 M, a charging unit  2 M, exposing unit  3 M, developing unit  4 M, primary transfer roller  5 M as a primary transfer unit, and cleaning unit  6 M. The image forming unit  10 C for forming cyan colored images includes a photoreceptor  1 C, a charging unit  2 C, exposing unit  3 C, developing unit  4 C, primary transfer roller  5 C as a primary transfer unit, and cleaning unit  6 C. The image forming unit  10 K for forming black colored images includes a photoreceptor  1 K, a charging unit  2 K, exposing unit  3 K, developing unit  4 K, primary transfer roller  5 K as primary transfer unit, and cleaning unit  6 K. 
   An intermediate transfer unit  7  includes an intermediate transfer body  70  that circulates, driven by plural rollers, and serves as the second image carrier which is a semiconductive endless belt supported by the rollers to be able to circulate. 
   Images in respective colors formed by the image forming units  10 Y,  10 M,  10 C and  10 Y are sequentially transferred onto an circulating intermediate transfer body  70  by the primary transfer rollers  5 Y,  5 M,  5 C and  5 K to form a composite color image. Each sheet S loaded on one of the sheet feeding tray  20 , manual sheet feeding tray C and the large capacity tray LCT is fed one by one by a sheet feeding roller  106  being a sheet feeding member and separating rollers  107 , conveyed through pre-registration rollers  109 , which are the first registration member, intermediate rollers  22 A,  22 B,  22 C and  22 D, which are conveying members, and then the front end of the sheet S is collided with registration rollers  23 , which are the second registration member so that angle deviation of the sheet is corrected. 
   Thereafter, synchronizing with image forming by the image forming units  10 Y,  10 M,  10 C and  10 K, registration rollers  23  start rotating to convey the sheet S to the secondary transfer roller  5 A being the secondary transfer section to transfer the color image onto the sheet S in a batch. The sheet S onto which the color image has been transferred is subjected to fixing processing with a fixing device  24  and then sandwiched by ejection rollers  25  to be loaded on an external ejection tray  26 . 
   On the other hand, from the intermediate transfer body  70  after transferring the color image onto the sheet S, residual toner is removed by a cleaning unit  6 A and collected into a box. 
   The primary transfer roller  5 K is always in press contact with the photoreceptor  1 K during image forming. The other primary transfer rollers  5 Y,  5 M and  5 C are in press contact with the corresponding photoreceptors  1 Y,  1 M and  1 C only when a color image is formed. The secondary transfer roller  5 A comes in press contact with the intermediate transfer body  70  only when the sheet S comes and secondary transfer is performed. 
   Next, a sheet feeding device in accordance with the invention to be used for the image forming apparatus in  FIG. 1  will be described in details, taking the example of the large capacity tray LCT. 
   As shown in  FIG. 1 , the large capacity tray LCT is provided with an opening and closing cover F as a mechanism to open and close the sheet feeding section. Further, an opening and closing detection sensor H is provided to detect opening and closing of the opening and closing cover F. 
     FIG. 2  is a perspective view showing the sheet feeding section in a state where the opening and closing cover F is removed from the large capacity tray LCT. In  FIG. 2 , plural sheets S are loaded on a sheet loading table  20   a , shown in  FIG. 1 , and supported to be able to rise and fall. Regulating members  104  for regulating the edges of sheets S move in the direction that is orthogonal to the sheet S feeding direction (shown as X direction) and is the transverse direction (shown as Z direction and Reverse Z direction) in the present embodiment. The regulating members  104  contact with the both sides of sheets S loaded on the sheet loading table  20   a  to regulate the both sides of the sheets S. A back edge regulating member  105  moves in the sheet S feeding direction (shown as X direction and Reverse X direction). The back edge regulating member  105  regulates the back edges of the sheets S in the sheet feeding direction. A sheet feeding roller  106  for feeding sheets is provided at the front end, in the sheet feeding direction, of sheets S and press-contacts the uppermost sheet S at a predetermined pressure. 
   When the sheet feeding roller  106  rotates in the direction arrow ‘a’, the uppermost sheet S is conveyed in the direction arrow ‘b’ and is conveyed to the separating rollers  107  provided on the downstream side of the sheet feeding roller  106 . When double feeding occurs, the lower separating roller  107   a  which is rotated by a torque limiter in the same direction as arrow ‘a’ pushes back the sheets after the uppermost one so that only the uppermost one sheet is conveyed by an upper separating roller  107   b  rotating in the arrow direction. Herein, the pair of the lower separating roller  107   a  and upper separating roller  107   b  form the separating rollers  107 . 
   The front end of a sheet S conveyed by the upper separating roller  107   b  is collided with the pre-registration rollers  109 , which are the first registration member. The pre-registration rollers  109  are a pair of facing rollers and rotate in the arrow direction. After the sheet S is collided with the pre-registration rollers  109 , the pre-registration rollers  109  starts conveying the sheet S at a predetermined timing, and the sheet S is conveyed through the registration rollers  23  being the second registration member to the secondary transfer roller  5 A. 
   Herein, the registration members in accordance with the invention have functions to start and stop sheet conveying and to correct angle deviation of a sheet that is conveyed, under control by a conveyance control section  303  of a control unit A. 
   Each regulating member  104  is provided with a small fan  120  as a sheet separating member and an air feed opening  122 . Air fed out upward from the fan  120  turns 90 degrees by a fan fitting plate and is blown out from the air feed opening  122  substantially horizontally. The air feeding opening  122  is open near the top of the regulating member  104  and has a grid form so that foreign objects do not enter to damage the fan  120 . 
   When the fan  120  rotates, air is fed out from the air feeding opening  122  to several sheets which are at the top portion of loaded sheets S. The fed air flows in from one side of the several sheets at the top portion of the sheets S and flows out through the gaps between the sheets. Thus, the tight-contact between sheets is weakened, and accordingly the several sheets at the top portion of the sheets S are separated into respective sheets. The sheet feeding roller  106  feeds only the uppermost sheet of such separated sheets S. 
   The control unit A of the image forming apparatus provided with the sheet feeding device in accordance with the invention will be described below, referring to the block diagram in  FIG. 3 . 
   The control unit A in accordance with the invention includes a CPU, a ROM that stores a control program, a memory  305  that stores image data, etc., and controls respective members shown in  FIGS. 1 and 2 . In order to describe objects of control in categories, the control unit A is described for convenience in categories of a system control section  300 , image forming control section  301 , conveyance control section  303 , operation-unit control section  304 , reading control section  306  and LCT control section  308  that controls driving and stopping position of the sheet loading table of the large capacity tray LCT. 
   The system control section  300  controls the respective control sections of the image forming apparatus as a whole and performs scheduling of image forming and the like. 
   The image forming control section  301  controls the image forming units  10 Y,  10 M,  10 C and  10 K, the intermediate transfer body  7 , the fixing device  24 , etc. 
   The conveyance control section  303  receives a signal transmitted from the system control section  300 , and controls the sheet feeding roller  106 , separating rollers  107 , pre-registration rollers  109 , intermediate rollers  22 A,  22 B,  22 C and  22 D, and registration rollers  23 . Specifically, the conveyance control section  303  controls motors that drive the respective rollers and electromagnetic clutches that switch drives. 
   The control section  304  of the operation unit controls the operation unit  302  related to display and operational input with an operation panel. 
   The reading control section  306  controls the operation of the image reading device SC. 
   The LCT control section  308  controls a driving motor  165  that drives lifting and lowering of the sheet loading table  20   a , namely, controls lifting of the sheet loading table  20   a  so that sheets move up to a sheet feeding position, and controls lowering of the sheet loading table  20   a  to a lower position to supply sheets. Specifically, when Power ON or closing of the opening and closing cover F has been detected, the LCT control section  308  drives the driving motor  165  to start lifting of the sheet loading table  20   a , and keeps lifting the sheet loading table  20   a  until the top surface of the loaded sheets is detected by the top surface detection sensor  139  provided at the upper portion, and then stops the sheet loading table  20   a . Thus, sheets are held at the sheet feeding position, and thereby it becomes possible to feed sheets. 
   When Power OFF or opening of the opening and closing cover is detected, the LCT control section  308  drives the driving motor  165  to lower the sheet loading table  20   a  to a lower position. 
   Next, control of lifting and lowering of the sheet loading table  20   a  and adjustment of the regulating members  104  will be described, referring to  FIG. 4 . 
   A lowering mechanism in the present embodiment is implemented by an opening and closing detection sensor H to detect the opening operation of the opening and closing cover F which serves as an opening and closing mechanism; Control  1  to lower the sheet loading table that holds sheets at the sheet feeding position to the lower position in association with the opening operation when the opening and closing sensor has detected the opening operation; and the LCT control section  308 , in the control device A, for the Control  1 . 
   Further, a holding mechanism that holds the sheet loading table to hold sheets at the sheet feeding position in no association with the opening operation of the opening and closing mechanism is implemented by the opening and closing detection sensor H to detect the opening operation of the opening and closing cover F which serves as the opening and closing mechanism; Control  2  not to lower the sheet loading table that holds sheets at the sheet feeding position to the lower position in association with the opening operation when the opening and closing sensor has detected the opening operation, but to keep the drive of the sheet loading table in a stopping state so as to hold sheets at the sheet feeding position; and the LCT control section  308 , in the control device A, for the Control  2 . 
   In the invention, based on setting for holding or lowering the sheet feeding table  20   a  via the input section  307  of the operation unit  302 , the LCT control section  308  controls to perform stopping by switching two positions, with Control  1  to hold the sheet loading table  20   a , keeping it stopped at the position that allows feeding of sheets, and with Control  2  to lower the sheet feeding table  20   a  to the lower position for supplying sheets and stop there the sheet feeding table  20   a.    
   Next, control of lifting and lowering of the sheet loading table  20   a  in accordance with the invention will be described in detail, referring to a flowchart in  FIG. 4 . 
   The opening and closing sensor H always monitors opening of the opening and closing cover F (step-S 1 ). When the opening and closing detection sensor H detects opening of the opening and closing sensor F (Yes), the input section  307  determines whether input to hold the sheet feeding position has been set (step-S 2 ). If input to hold the position has been set (Yes), Control  2  is executed to prohibit driving of the sheet loading table and hold the stopping state (step-S 3 ). Thus, a user or service man can adjust the regulating members  104  of the large capacity tray LCT, while holding sheets at the sheet feeding position. If input to hold the sheet feeding position has not been set (No), Control  1  is executed to drive the sheet loading table downward to the lower position (step-S 4 ). Thus, the sheet loading table is lowered to the lower position, allowing the user to supply sheets. 
   Then, the opening and closing detection sensor H monitors closing of the opening and closing cover F (step-S 5 ). When the opening and closing detection sensor H detects closing of the opening and closing sensor F (Yes), then driving is controlled to lift the sheet loading table up to a point where sheets are at the sheet feeding position (step-S 6 ). Herein, when Control  1  is executed, control to drive the sheet loading table is not executed particularly, since the sheets are held at the sheet feeding position. 
   Next, adjustment of the regulating members  104  to be performed after execution of step-S 3 , mentioned above, will be described. 
   The larger the capacity of the sheet feeding device, the regulating members  104  to guide the both sides of sheets have the longer vertical surfaces in the height direction, wherein the upper position and the lower position have different position dimensions in the transverse direction, which actually does not allow accurate dimensional positioning even if positioning is performed at a lower part. Further, in prior arts, in a sheet feeding device connected to an image forming apparatus, a sheet loading table is lowered to a lower position when the opening and closing cover F of a LCT is opened for a work of sheet supply or on a trouble, such as a jam. Accordingly, even if the image forming apparatus and the sheet feeding device is stopped for position adjustment of sheets in the transverse direction in a light printing process, and thus the positions of the regulating members  104  are adjusted for adjustment of the position of sheets to be fed, when the sheets reach the actual sheet feeding position, gaps may be created between the regulating members  104  and the sheets, which causes angle-deviation of sheets. 
   In the present invention, in order to avoid such a problem, when the opening and closing cover F of the LCT is opened by input setting via the input section  307  of the operation unit  302  at the time of adjusting the regulating members  104 , the sheet loading table is controlled to hold a stopping state while it is held at the position for sheet feeding. 
   An adjusting mechanism, in accordance with the invention, for adjustment of the position of a regulating member  104  in the transverse direction includes a clamp  135  to fix the position, scale gauge  130  integrally fixed to the regulating member  104 , index  137  fixed to the main body of the LCT, and the regulating member  104  movable in the transverse direction. 
   Adjustment of the position of the regulating member  104  by the adjusting mechanism unclamps the clamp  135  fixing the position, moves the regulating member  104  in the transverse direction (in Z direction or Reverse Z direction) for adjustment, with an indication by the measure  131  of the scale gauge  130  integrally fixed to the regulating member  104  and an indication by the index  137  fixed to the main body. Finally, the clamp  135  is tightened to fix the position. Since this adjusting operation can be performed in a state where sheets S are at the sheet feeding position, it is possible to make an accurate adjustment, while narrowing the gap between the regulating member  104  and the edges of the sheets S and visually checking so that the sheets S have no angle deviation. Further, micro adjustments, including readjustment at any time needed, can be made easily with the simple mechanism. 
   Further in the invention, when sheets are supplied to the LCT, the sheet loading table  20   a  is lowered to the lower position so that a large amount of sheets can be easily supplied. 
   An adjustment method for adjustment of regulating members  104  in the present Embodiment 1 will be described. In the adjustment method for adjustment of regulating members  104  in accordance with the present invention, a process is included, wherein when setting to hold the sheet loading table  20   a  by prohibiting a fall of it has been input via the input section  307  of the operation unit  302 , the LCT control section  308  controls the driving of the sheet loading table  20   a  such that the sheet loading table  20   a  does not fall and sheets are held at the sheet feeding position. Thereafter, a process is executed that adjusts the position of the regulating members  104  in the state where the sheets are held at the sheet feeding position. On the other hand, another process is included, wherein when setting to lower the sheet loading table  20   a  that does not prohibit a fall of it is input via the operation unit  302 , the LCT control section controls the sheet loading table  20   a  to fall to a lower position where sheets can be supplied. Then, a process to supply sheets onto the sheet loading table  20   a  is executed. 
   In the present embodiment, although prohibition of lowering the sheet loading table  20   a  is set by an input via the input section  307  of the operation unit  302  of the image forming apparatus, it is also possible, for example, to provide an input section on the sheet feeding device LCT. 
   Embodiment 2 
   A sheet feeding device shown in  FIGS. 5 ,  6   a  to  6   d ,  7   a  and  7   b  in Embodiment 2 in accordance with the present invention will be described below as an example. 
   In Embodiment 2, a sheet feeding section is opened by drawing out a sheet feeding tray  101  from a main body frame 
     FIG. 5  is a perspective view showing a state where the sheet feeding tray  101  is drawn out from a main body frame  100 B of the sheet feeding device.  FIG. 6   a  and  FIG. 6   b  are a front view and side view of the sheet feeding tray in a state where sheets are at a sheet feeding position, while  FIG. 6   c  and  6   d  are a front view and side view showing a state where sheets are supplied onto a sheet loading table. 
   The structure of the sheet feeding tray will be described, referring to  FIG. 5 . The tips of wires  142   a ,  142   b ,  142   c  and  142   d  are fixed at the four corners of the sheet loading table  20   a  and guided by plural guide pulleys  143  provided and fixed to the sheet feeding tray  101 . The other tips of the wires are fixed to winding pulleys  145  A and  145 B and the wires are wound and released. Further, guide rollers  151  arranged at the four corners of the sheet loading table  20   a  and guide rails  152  provided on the main body of the sheet feeding tray  101  enable stable rise and fall of the sheet loading table  20   a.    
   The winding pulleys  145 A and  145 B are integrally connected with a drive transmission shaft  146 . As shown in  FIG. 6   b , an engaging section provided at one end of the drive transmission shaft  146  is coupled with a coupling member  156  of a drive motor  165  provided on the main body frame  100 B, and thereby the drive is transmitted. The drive transmission section includes the wires  142   a ,  142   b ,  142   c  and  142   d , the winding pulley  145 A and  145 B, and the drive transmission shaft  146 . The drive motor  165  is driven to lift the sheet loading table  20   a . When the sheet feeding tray  101  is drawn out from the main body frame  100 B, coupling between the engaging section and the coupling member  156  is released to cut off the transmission of the driving force, and accordingly the sheet loading table  20   a  falls to the lower position with the gravity thereof. 
   On the other hand, as shown in  FIG. 7   a  being a detailed figure of A in  FIG. 6   a  and  FIG. 7   b  being a detailed drawing of C in  FIG. 6   c , the drive transmission shaft  146  for the winding pulleys  145 A and  145 B is fitted with a ratchet gear  147 . A crank box  160  is provided on the side wall of the front part of the sheet feeding tray  101 . The crank box  160  is provided with a clamp claw  163  as an inhibiting member through a lock button  161  and a spring  162 , facing the ratchet gear  147 . The clamp claw  163  is engaged with the ratchet gear  147  to inhibit driving.  FIG. 7   a  shows the state where the clamp claw  163  is at the inhibiting position, and  FIG. 7   b  shows the state where the clamp claw  163  is at the releasing position. By operation of the lock button  161  through the spring  162 , the clamp claw  163  is engaged with the ratchet gear  147  to inhibit driving, or the engagement is released to permit the ratchet gear  147  to be driven. When the ratchet gear  147  is in the state of being stopped by the engagement with the clamp claw  163 , the sheet feeding tray  101  is drawn out and the drive transmission section is released, and even if the connection with the drive motor  165  is cut off, the drive transmission shaft  146  is inhibited from driving, and thus the sheet loading table  20   a  does not fall and the sheets can be held at the sheet feeding position. The regulating members  104  can be adjusted in this state. 
   An adjusting mechanism to adjust the transverse position of a regulating member  104  in accordance with the invention includes a clamp  135 , scale gauge  130  integrally fixed to the regulating member  104 , index  137  fixed to the main body, and the regulating member  104  movable in the transverse direction. 
   In adjustment of the position of the regulating member  104  by the adjusting mechanism, the transverse position of the regulating member  104  is moved and adjusted with an indication by the measure  131  of the scale gauge  130  integrally fixed to the upper portion of the regulating member  104  and an indication by the index  137  fixed on a fixing frame  101 A of the sheet feeding tray  101 , and the regulating member  104  is fixed at a position decided by the clamp  135 . Since the operation of this adjustment can be performed in a state where sheets S are at the feeding position, it is possible to make an accurate adjustment, while narrowing the gap between the regulating member  104  and the ends of the sheets S and visually checking so that the sheets S have no angle deviation. Further, micro adjustments, including readjustment at any time needed, can be made easily with the simple mechanism. 
   When the sheet feeding tray  101  is inserted into the sheet feeding device main body  100 B in this state after adjustment, insertion of the sheet feeding tray  101  is detected and the drive motor  165  is driven, based on a detection signal, to start rising of the sheet loading table  20   a . The sheet loading table  20   a  rises until the top surface of the loaded sheets is detected by a top surface detection sensor  139  provided at the upper part, and the sheet loading table  20   a  stops. In such a manner, the sheets are held at the sheet feeding position and sheet feeding becomes possible. 
   In order to draw out the sheet feeding tray  101  and supply sheets, the engagement of the ratchet gear  147  with the clamp claw  163  is released by releasing the lock button  161 , the winding pulleys provided at the drive transmission shaft  146  becomes freely rotatable, and the sheet loading table  20   a  falls to the lower position with the gravity thereof. 
   Further, the ratchet gear  147  is provided with a one way clutch  148  which allows the drive transmission shaft  146  to rotate in the direction to lift the sheet loading table  20   a  even when the clamp claw  163  inhibits drive rotation of the ratchet gear  147 . In such a manner, even when the clamp claw  163  inhibits drive rotation of the ratchet gear  147  during image forming, if the top surface of sheets S becomes lower than the sheet feeding position when some of the sheets S have been fed out, the sheet loading table  20   a  can be lifted such that the remaining sheets S rises to the sheet feeding position. 
   In the sheet feeding device including the sheet feeding tray  101  in the present Embodiment 2, the regulating members  104 , scale gauges  130 , sheet feeding roller  106 , lower separation roller  107   a , upper separation roller  107   b , control device and the like have the similar structures and functions as those of the large capacity tray LCT in aforesaid Embodiment 1, and therefore detailed description is omitted here. 
   Further, by making it possible to shift the sheet feeding roller  106  away to an upper position, easy adjustment of regulating members and supply of sheets are achieved. 
   In accordance with the invention, it is possible to adjust the regulation of the side of sheets, in the transverse direction, not at a lower position below a sheet feeding position, but holding the sheets at the sheet feeding position. In such a manner, the traverse position of sheets can be accurately adjusted with a simple structure. Accordingly, creation of a shift or angle deviation between sheets and images can be prevented in image forming on the sheets, and stable image forming in a high quality without deviation can be attained. Further, when it is necessary to supply sheets, a sheet loading table is lowered to a lower position, allowing efficient supply of sheets.