Sheet supply device and foil transfer device

Abstract

To provide a sheet supply device and a foil transfer device capable of shortening an interval between sheets.SOLUTION: A sheet supply device 11 and a foil transfer device 1 include: a sensor SS1 that detects a sheet S; a sensor SS2 arranged upstream of the sensor SS1 in a conveyance direction of the sheet S and at a position different from the sensor SS1 in a width direction of the sheet S orthogonal to the conveyance direction; and a control unit. The control unit performs shape determination processing for determining a shape of a first sheet S based on detection results of the sensors SS1 and SS2 after supplying the first sheet S, and supplies a next second sheet S at the timing when the sensor SS1 no longer detects the first sheet S. The control unit supplies a next third sheet S at the timing when the sensor SS1 no longer detects the second sheet S when the first sheet S does not have a predetermined shape, and supplies the next third sheet S at the timing when the sensor SS2 no longer detects the second sheet S when the first sheet S has the predetermined shape.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sheet supplying device and a foil transfer device. [Background technology]

[0002] Conventionally, a foil transfer device is known that includes a transfer unit that transfers foil to a sheet, a supply roller that supplies the sheet toward the transfer unit, and a sheet sensor that detects the sheet being supplied toward the transfer unit (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-122908 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when multiple sheets are fed continuously, a method of controlling the feed rollers so that the next sheet is fed when the sheet sensor no longer detects the preceding sheet is conceivable, but it is desirable to keep the interval between the preceding sheet and the next sheet as short as possible, because if the interval between sheets is long, for example, the printing time will be long when foil is transferred to multiple sheets continuously, or the foil film will be wasted if it is transported between the sheets.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a sheet supplying device and a foil transfer device that can shorten the interval between sheets. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the sheet feeding device includes a feed roller that feeds a sheet toward a sheet processing section that forms an image on the sheet or reads the image on the sheet, a first sheet sensor that detects the sheet fed toward the sheet processing section, a second sheet sensor that detects the sheet fed toward the sheet processing section, the second sheet sensor being arranged upstream of the first sheet sensor in the sheet conveying direction and at a different position from the first sheet sensor in the sheet width direction perpendicular to the conveying direction, and a control section. When a plurality of sheets are continuously supplied, the control unit controls the supply roller to supply the first sheet at a predetermined timing. After supplying the first sheet, the control unit executes a shape determination process for determining the shape of the first sheet based on the detection results of the first sheet sensor and the second sheet sensor. The control unit controls the supply roller to supply the second sheet following the first sheet at a timing when the first sheet sensor no longer detects the first sheet. If the shape determination process determines that the first sheet does not have a specified shape, the control unit controls the supply roller to supply a third sheet following the second sheet at a time when the first sheet sensor no longer detects the second sheet. Furthermore, when the shape determination process determines that the first sheet has a predetermined shape, the control unit controls the supply roller to supply the third sheet at a timing when the second sheet sensor no longer detects the second sheet.

[0007] According to this configuration, when the first sheet has a predetermined shape, the third sheet is supplied at the time when the second sheet sensor, which is located upstream in the conveying direction from the first sheet sensor, no longer detects the second sheet, thereby shortening the distance between the second sheet and the third sheet.

[0008] In the above-mentioned sheet supplying device, when four or more sheets are supplied continuously, if the shape determination process determines that the first sheet has a predetermined shape, the control unit can be configured to supply the fourth and subsequent sheets at a time when the second sheet sensor no longer detects the preceding sheet.

[0009] According to this, the interval between the third and subsequent sheets and the preceding sheets can be shortened.

[0010] In the above-described sheet feeding device, the second sheet sensor may be arranged at a position farther from the center of the sheet processing section in the width direction than the first sheet sensor.

[0011] In the above-described sheet feeding device, the first sheet sensor may be arranged at a position closer to the center of the sheet processing section than to an end of the sheet processing section in the width direction.

[0012] In the above-mentioned sheet supplying device, the control unit can be configured to determine in the shape determination process that the first sheet has a predetermined shape if the time when the first sheet sensor detects the first sheet is the same as the time when the second sheet sensor detects the first sheet.

[0013] In the above-mentioned sheet supplying device, the control unit can be configured to determine in the shape determination process that the first sheet does not have a predetermined shape if the second sheet sensor does not detect the first sheet between the time when the first sheet sensor detects the first sheet and the time when it no longer detects the first sheet.

[0014] In the above-mentioned sheet supplying device, the control unit can be configured to determine in the shape determination process that the first sheet does not have a predetermined shape if the time during which the first sheet sensor detects the first sheet is longer than the time during which the second sheet sensor detects the first sheet.

[0015] In addition, in order to achieve the above-mentioned objective, the foil transfer device is a foil transfer device that overlays a sheet on a foil film containing foil and transfers the foil to the sheet, and is equipped with a transfer unit as a sheet processing unit that transfers the foil to the sheet, and the above-mentioned sheet supply device that supplies the sheet to the transfer unit.

[0016] This configuration allows the distance between the second sheet and the third sheet to be shortened, which can reduce the printing speed when transferring foil to multiple sheets in succession and reduce waste of foil film. Effect of the Invention

[0017] According to the present invention, the distance between the second sheet and the third sheet can be shortened. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2A is a diagram showing a foil transfer device including a sheet supplying device according to an embodiment, and FIG. 2B is a cross-sectional view showing the configuration of a foil film. [Diagram 2] FIG. 2 is a diagram showing the foil transfer device with the cover open. [Diagram 3] FIG. 4 is a diagram showing the arrangement of sensors for detecting a sheet. [Figure 4] 1A to 1D are diagrams illustrating an example of the timing and intervals at which a first sheet is supplied when the first sheet has a predetermined shape. [Diagram 5] 10A to 10D are diagrams illustrating an example of the timing and intervals at which a first sheet is supplied when the first sheet does not have a predetermined shape. [Figure 6] 13A to 13D are diagrams illustrating other examples of the timing and intervals at which the first sheet is supplied when the first sheet does not have a predetermined shape. [Figure 7] 10 is a flowchart showing an example of an operation of a control unit. [Figure 8] 13 is a flowchart illustrating an example of a shape determination process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Next, an embodiment of the invention will be described in detail with reference to the drawings as appropriate. In the following description, directions will be described in the directions shown in Fig. 1(a). That is, the right side of Fig. 1(a) will be referred to as "front", the left side as "rear", the front side of the paper as "left", and the back side of the paper as "right". Also, the top and bottom of Fig. 1(a) will be referred to as "top and bottom".

[0020] As shown in Fig. 1(a), foil transfer device 1 is a device for overlaying sheet S on foil film F containing foil and transferring the foil to sheet S. Foil transfer device 1 forms an image of foil on sheet S by transferring a foil such as aluminum onto a toner image formed on sheet S by an image forming device such as a laser printer. Foil transfer device 1 includes a housing 2, a sheet tray 3, a sheet conveying unit 10, a film supply unit 30, and a transfer unit 50 as a sheet processing unit.

[0021] The housing 2 is made of resin or the like, and includes a housing main body 21 and a cover 22. The housing body 21 has an opening 21A (see FIG. 2) at the top. The opening 21A is an opening for attaching and detaching a film unit FU to and from the housing body 21, which will be described later. Cover 22 is a member for opening and closing opening 21A. A rear end portion of cover 22 is rotatably supported by housing body 21. Cover 22 is rotatable between a closed position where it closes opening 21A and an open position where it opens opening 21A (see FIG. 2).

[0022] The sheet tray 3 is a tray on which sheets S, such as paper and overhead projector films, are placed. The sheet tray 3 is provided at the rear of the housing 2. The sheet S is placed on the sheet tray 3 with the surface on which the toner image is formed facing downward.

[0023] The sheet transport section 10 includes a sheet supply device 11 and a sheet discharge device 12 . The sheet supplying device 11 is a device that supplies the sheets S on the sheet tray 3 one by one to the transfer unit 50. The sheet supplying device 11 includes a pickup roller 11A as an example of a supply roller, a retard roller 11B, and a conveying roller 11C.

[0024] The pickup roller 11A is a roller for supplying the sheet S on the sheet tray 3 toward the transfer unit 50.

[0025] The retard roller 11B is a roller for separating the sheet S conveyed by the pickup roller 11A into one sheet. The retard roller 11B is disposed above the pickup roller 11A. The retard roller 11B is rotatable in a direction to return the sheet S overlapping the sheet S sent out by the pickup roller 11A toward the sheet tray 3.

[0026] The conveying roller 11C is made up of a pair of rollers, and each roller rotates while sandwiching the sheet S between the pair of rollers, thereby enabling the sheet S to be conveyed. The conveying roller 11C is disposed between the pickup roller 11A and the transfer unit 50, and conveys the sheet S sent out by the pickup roller 11A to the transfer unit 50.

[0027] The sheet discharge device 12 is a device that discharges the sheet S that has passed through the transfer unit 50 to the outside of the housing 2. The sheet discharge device 12 includes intermediate discharge rollers 12A and discharge rollers 12B. Each of the intermediate discharge rollers 12A and discharge rollers 12B is made up of a pair of rollers, and each roller rotates with the sheet S sandwiched between the pair of rollers, thereby enabling the sheet S to be conveyed.

[0028] The intermediate discharge rollers 12A are rollers for transporting the sheet S sent out from the transfer unit 50 toward the discharge rollers 12B. The intermediate discharge rollers 12A are disposed downstream of the transfer unit 50 in the transport direction. In the following description, the transport direction of the sheet S is also simply referred to as the "transport direction."

[0029] The discharge rollers 12B are rollers for discharging the sheet S sent out by the intermediate discharge rollers 12A to the outside of the housing 2. The discharge rollers 12B are disposed downstream of the intermediate discharge rollers 12A in the transport direction.

[0030] The film supplying section 30 is a section that supplies the foil film F so as to be superimposed on the sheet S conveyed from the sheet supplying device 11. The film supplying section 30 includes a film unit FU and a motor 80.

[0031] 2, the film unit FU is detachable from the top of the housing main body 21. The film unit FU includes a supply reel 31, a take-up reel 35, a first guide shaft 41, a second guide shaft 42, and a third guide shaft 43. A foil film F is wound around the supply reel 31 of the film unit FU.

[0032] As shown in FIG. 1(b), the foil film F has a supporting layer F1 and a supported layer F2. The supporting layer F1 is a tape-shaped transparent base material made of a polymeric material, and supports the supported layer F2.

[0033] The supported layer F2 has a release layer F21, a transfer layer F22, and an adhesive layer F23. The release layer F21 is a layer for facilitating peeling of the transfer layer F22 from the support layer F1, and is disposed between the support layer F1 and the transfer layer F22. The release layer F21 contains a transparent material, such as a wax-based resin, that is easily peeled from the support layer F1.

[0034] The transfer layer F22 is a layer to be transferred to the toner image and includes a foil. The foil is a thin metal such as gold, silver, copper, or aluminum. The transfer layer F22 also includes a coloring material such as gold, silver, or red, and a thermoplastic resin. The transfer layer F22 is disposed between the release layer F21 and the adhesive layer F23.

[0035] The adhesive layer F23 is a layer for making it easier for the transfer layer F22 to adhere to the toner image. The adhesive layer F23 contains a material that easily adheres to the toner image heated by the transfer unit 50, such as a vinyl chloride resin or an acrylic resin.

[0036] 1(a), the supply reel 31 is made of resin or the like, and has a supply shaft portion 31A around which the foil film F is wound. One end of the foil film F is fixed to the supply shaft portion 31A. The take-up reel 35 is made of resin or the like, and has a take-up shaft portion 35A for taking up the foil film F. The other end of the foil film F is fixed to the take-up shaft portion 35A.

[0037] For convenience, Fig. 1(a) and other figures show a state in which the foil film F is wound to its maximum around both the supply reel 31 and the take-up reel 35. In reality, when the film unit FU is new, the diameter of the roll-shaped foil film F wound around the supply reel 31 is at its maximum, and either no foil film F is wound around the take-up reel 35 or the diameter of the roll-shaped foil film F wound around the take-up reel 35 is at its minimum. Also, at the end of the life of the film unit FU (when the foil film F has been used up), the diameter of the roll-shaped foil film F wound around the take-up reel 35 is at its maximum, and either no foil film F is wound around the supply reel 31 or the diameter of the roll-shaped foil film F wound around the supply reel 31 is at its minimum.

[0038] The first guide shaft 41, the second guide shaft 42, and the third guide shaft 43 are roller-shaped shafts for changing the traveling direction of the foil film F. The first guide shaft 41, the second guide shaft 42, and the third guide shaft 43 are made of SUS (stainless steel) or the like.

[0039] The first guide shaft 41 is located upstream of the transfer section 50 in the conveying direction of the sheet S. The first guide shaft 41 changes the traveling direction of the foil film F pulled out from the supply reel 31 so that it is approximately parallel to the conveying direction of the sheet S. The foil film F guided by the first guide shaft 41 is conveyed toward the transfer section 50 with the supported layer F2 (see FIG. 1(b)) facing upward. In addition, the sheet S is superimposed on the foil film F with the supported layer F2 facing upward, and is conveyed toward the transfer section 50 together with the foil film F.

[0040] The second guide shaft 42 is located downstream of the transfer section 50 in the conveying direction of the sheet S. The second guide shaft 42 peels the foil film F from the sheet S by changing the traveling direction of the foil film F that has passed through the transfer section 50 to a direction different from the conveying direction of the sheet S.

[0041] The third guide shaft 43 is a member that determines the traveling direction of the foil film F that is changed by the second guide shaft 42. More specifically, the third guide shaft 43 determines the peeling angle, which is the angle of the foil film F when the foil film F is peeled off from the sheet S. Here, the peeling angle is the angle between the portion of the foil film F that is stretched between the first guide shaft 41 and the second guide shaft 42 and the portion that is stretched between the second guide shaft 42 and the third guide shaft 43. The third guide shaft 43 changes the traveling direction of the foil film F guided by the second guide shaft 42 and guides it to the take-up reel 35.

[0042] With the film unit FU attached to the foil transfer device 1, the take-up reel 35 is driven to rotate counterclockwise in the figure by a motor 80 provided in the housing 2. When the take-up reel 35 rotates, the foil film F wound around the supply reel 31 is pulled out, and the pulled-out foil film F is guided by the guide shafts 41 to 43 and wound up around the take-up reel 35. In more detail, during foil transfer, the foil film F is fed out by the pressure roller 51 and the heat roller 61, so that the foil film F is pulled out from the supply reel 31. Then, the foil film F fed out from the pressure roller 51 and the heat roller 61 is wound up around the take-up reel 35.

[0043] The transfer unit 50 is a section for forming an image on the sheet S. More specifically, the transfer unit 50 heats and presses the sheet S and the foil film F in a superimposed state, thereby transferring the foil (transfer layer F22) onto the toner image formed on the sheet S, thereby forming an image of the foil on the sheet S. The transfer unit 50 includes a pressure roller 51, a heating roller 61, and a pressure contact / separation mechanism 70. The transfer unit 50 heats and presses the sheet S and the foil film F in a superimposed state at the nip portion between the pressure roller 51 and the heating roller 61.

[0044] The pressure roller 51 is a roller in which the periphery of a cylindrical core metal is covered with a rubber layer made of silicone rubber. The pressure roller 51 is disposed above the foil film F and is capable of contacting the back surface of the sheet S (the surface opposite to the front surface on which the toner image is formed). Both ends of the pressure roller 51 are rotatably supported by the cover 22. The pressure roller 51 sandwiches the sheet S and the foil film F between itself and the heating roller 61, and is driven to rotate by the motor 80 to rotate the heating roller 61.

[0045] The heating roller 61 is a roller in which a heater H is disposed inside a cylindrical metal tube, and heats the foil film F and the sheet S. The heating roller 61 is disposed below the foil film F and is in contact with the foil film F. The heating roller 61 heats the foil film F and the sheet S.

[0046] The pressure contact / separation mechanism 70 is a mechanism for moving one of the heating roller 61 and the pressure roller 51 between a pressure contact position where it is in pressure contact with the other roller and a spaced position where it is spaced from the other roller. In this embodiment, the pressure contact / separation mechanism 70 is configured to move the heating roller 61 between the pressure contact position shown by the solid line in Fig. 1 and the spaced position shown by the imaginary line in Fig. 1. In this embodiment, the pressure contact position is a position where the heating roller 61 is in pressure contact with the pressure roller 51, and the spaced position is a position where the heating roller 61 is spaced from the pressure roller 51.

[0047] In the foil transfer device 1 configured in this manner, the sheets S placed on the sheet tray 3 with their front surfaces facing downwards are transported one by one by the sheet supply device 11 toward the transfer unit 50. The sheets S are overlapped with the foil film F supplied from the supply reel 31 on the upstream side of the transfer unit 50 in the transport direction, and are transported to the transfer unit 50 with the toner image on the sheet S and the supported layer F2 of the foil film F in contact with each other.

[0048] In the transfer section 50, as the sheet S and foil film F pass through the nip between the pressure roller 51 and the heating roller 61, they are heated and pressurized by the heating roller 61 and the pressure roller 51, and the foil (supported layer F2) is transferred onto the toner image.

[0049] After the foil is transferred, the sheet S and the foil film F are transported in a stuck state to the second guide shaft 42. When the sheet S and the foil film F pass the second guide shaft 42, the transport direction of the foil film F changes to a direction different from the transport direction of the sheet S, so that the foil film F is peeled off from the sheet S, that is, the supported layer F2 adhered to the toner image is peeled off from the supporting layer F1 of the foil film F.

[0050] The foil film F, which includes the supporting layer F1 peeled off from the sheet S and peeled off from the supported layer F2 adhered to the toner image on the sheet S, is taken up by the take-up reel 35. Meanwhile, the sheet S from which the foil film F has been peeled off is discharged by the sheet discharge device 12 to the outside of the housing 2 with the surface on which the foil has been transferred facing down.

[0051] 3, the sheet supplying device 11 further includes a trailing end detection sensor SS1 as an example of a first sheet sensor, a width detection sensor SS2 as an example of a second sheet sensor, a set detection sensor SS3, a discharge sensor SS4, and a control unit 100 (see FIG. 1). In the following description, the width direction of the sheet S, which is a direction perpendicular to the conveying direction of the sheet S, is also simply referred to as the "width direction." In this embodiment, the width direction corresponds to the left-right direction.

[0052] The trailing end detection sensor SS1 and the width detection sensor SS2 are sensors for detecting the sheet S being fed toward the transfer unit 50. The set detection sensor SS3 is a sensor for detecting the sheet S placed on the sheet tray 3. In the foil transfer device 1, the set detection sensor SS3 can detect whether or not the sheet S is placed on the sheet tray 3. The discharge sensor SS4 is a sensor for detecting the sheet S being sent out from the transfer unit 50.

[0053] Here, as the sensors SS1 to SS4, for example, a sensor including a lever that rotates when the sheet S comes into contact with it, and an optical sensor that detects the position of the lever can be used.

[0054] The trailing end detection sensor SS1, the width detection sensor SS2, and the set detection sensor SS3 are disposed upstream of the transfer unit 50 in the transport direction. The discharge sensor SS4 is disposed downstream of the transfer unit 50 in the transport direction.

[0055] Specifically, the trailing end detection sensor SS1 and the width detection sensor SS2 are disposed in the transport direction between the pickup roller 11A and the transfer unit 50. More specifically, the trailing end detection sensor SS1 and the width detection sensor SS2 are disposed in the transport direction between the pickup roller 11A and the transport roller 11C.

[0056] Further, the trailing end detection sensor SS1 is disposed at a position, in the width direction, closer to the center than to the end of the transfer unit 50. Specifically, the trailing end detection sensor SS1 is disposed near the center C of the heating roller 61 in the width direction.

[0057] The width detection sensor SS2 is disposed upstream of the trailing end detection sensor SS1 in the transport direction. Moreover, the width detection sensor SS2 is disposed at a position different from the trailing end detection sensor SS1 in the width direction. Specifically, the width detection sensor SS2 is disposed at a position farther from the center of the transfer unit 50 than the trailing end detection sensor SS1 in the width direction. More specifically, the width detection sensor SS2 is disposed between the center C and the left end of the heating roller 61 in the width direction.

[0058] In this embodiment, the foil transfer device 1 is configured to transport a sheet S of a standard size such as letter size, A4 size, or A5 size, with the center C of the transfer unit 50 (heat roller 61) in the width direction as the transport center. As an example, the width detection sensor SS2 is disposed at a position in the width direction where it can detect a sheet S having a width equal to or larger than the A5 size, but cannot detect a sheet S having a width equal to or smaller than the A6 size.

[0059] The set detection sensor SS3 is disposed upstream of the rear end detection sensor SS1 and the width detection sensor SS2 in the transport direction. More specifically, the set detection sensor SS3 is disposed upstream of the pickup roller 11A in the transport direction. More specifically, the set detection sensor SS3 is provided on the sheet tray 3. In addition, the set detection sensor SS3 is disposed at a position shifted to the right with respect to the center C of the heating roller 61 in the width direction.

[0060] The discharge sensor SS4 is disposed between the transfer unit 50 and the discharge roller 12B in the transport direction. More specifically, the discharge sensor SS4 is disposed between the intermediate discharge roller 12A and the discharge roller 12B in the transport direction. The discharge sensor SS4 is also disposed at a position closer to the center than to the end of the transfer unit 50 in the width direction. Specifically, the discharge sensor SS4 is disposed near the center C of the heating roller 61 in the width direction.

[0061] In this embodiment, the sensors SS1 to SS4 output an ON signal to the control unit 100 when they detect the sheet S, and output an OFF signal to the control unit 100 when they do not detect the sheet S. Therefore, the sheet S is detected when the signal output to the control unit 100 switches from an OFF signal to an ON signal, and the sheet S is no longer detected when the signal output to the control unit 100 switches from an ON signal to an OFF signal.

[0062] The control unit 100 (see FIG. 1(a)) includes a CPU, RAM, ROM, input / output circuits, etc., and performs various types of arithmetic processing based on programs and data stored in the ROM and the like, thereby executing control.

[0063] In this embodiment, when the control unit 100 continuously supplies a plurality of sheets S placed on the sheet tray 3, the control unit 100 sequentially supplies a first sheet S, a second sheet S following the first sheet S, and a third sheet S following the second sheet S, toward the transfer unit 50 at the timing described below. Note that in Figs. 4 to 6 to be referred to later, the first sheet S is represented as "S1", the second sheet S as "S2", the third sheet S as "S3", and the fourth sheet S following the third sheet S as "S4".

[0064] The control unit 100 controls the pickup roller 11A to supply the first sheet S at a predetermined timing. Specifically, when the control unit 100 receives a command to start foil transfer, the control unit 100 first executes a foil transfer preparation process. In the foil transfer preparation process, the control unit 100, for example, rotates the rollers 11B, 11C, 51, 12A, and 12B, controls the pressure contact / separation mechanism 70 to move the heating roller 61 to a pressure contact position, and controls the heater H of the heating roller 61 to heat the transfer unit 50 to a predetermined temperature for foil transfer. Then, the control unit 100 rotates the pickup roller 11A at a timing when the foil transfer preparation process is completed, and supplies the first sheet S toward the transfer unit 50.

[0065] After supplying the first sheet S, the control unit 100 executes a shape determination process to determine the shape of the first sheet S based on the detection results of the trailing end detection sensor SS1 and the width detection sensor SS2. The control unit 100 executes the shape determination process to determine the shape of the first sheet S, and controls the supply of the subsequent sheets S, assuming that a sheet S having the same shape as the first sheet S is placed on the sheet tray 3.

[0066] In the shape determination process, the control unit 100 determines that the first sheet S has a predetermined shape if the time when the trailing end detection sensor SS1 detects the first sheet S is the same as the time when the width detection sensor SS2 detects the first sheet S. In this embodiment, in the shape determination process, the control unit 100 determines that the first sheet S has a predetermined shape if the time from when the trailing end detection sensor SS1 detects the first sheet S to when it no longer detects the first sheet S is the same as the time from when the width detection sensor SS2 detects the first sheet S to when it no longer detects the first sheet S.

[0067] Specifically, the control unit 100 sets the shape determination flag FL to 1 when the first sheet detection time td1, which is the time from when the trailing end detection sensor SS1 outputs an ON signal to when it outputs an OFF signal, is the same as the second sheet detection time td2, which is the time from when the width detection sensor SS2 outputs an ON signal to when it outputs an OFF signal.

[0068] In this embodiment, the sheet S of a predetermined shape is typically a wide sheet S that is rectangular and has a width that can be detected by both the trailing end detection sensor SS1 and the width detection sensor SS2, as shown in FIG. 4(a). As an example, the sheet S of a predetermined shape is a sheet S of a standard size such as A4 size or A5 size. In the case of such a sheet S, the first sheet detection time td1 and the second sheet detection time td2 are the same. Here, the first sheet detection time td1 and the second sheet detection time td2 being the same are not limited to being completely the same, but also include the case where they are the same after the detection errors of the sensors SS1 and SS2 have been added or subtracted.

[0069] Furthermore, in the shape determination process, the control unit 100 determines that the first sheet S does not have a predetermined shape if the width detection sensor SS2 does not detect the first sheet S during the period from when the trailing end detection sensor SS1 detects the first sheet S to when it no longer detects the first sheet S. Specifically, the control unit 100 sets the shape determination flag FL to 0 if the signal output from the width detection sensor SS2 does not change from the OFF signal during the period from when the trailing end detection sensor SS1 outputs an ON signal to when it outputs an OFF signal.

[0070] Here, the sheet S not having the specified shape is, for example, a narrow sheet S that is rectangular and has a width that can be detected by the trailing end detection sensor SS1 but cannot be detected by the width detection sensor SS2, as shown in Fig. 5(a). As an example, the sheet S not having the specified shape is a sheet S having a width equal to or smaller than A6 size. In the case of such a sheet S, the signal output from the width detection sensor SS2 does not change from the OFF signal during the period from when the trailing end detection sensor SS1 outputs an ON signal to when it outputs an OFF signal.

[0071] Furthermore, in the shape determination process, the control unit 100 determines that the first sheet S does not have the predetermined shape if the time during which the trailing end detection sensor SS1 detects the first sheet S is longer than the time during which the width detection sensor SS2 detects the first sheet S. In this embodiment, in the shape determination process, the control unit 100 determines that the first sheet S does not have the predetermined shape if the time from when the trailing end detection sensor SS1 detects the first sheet S to when it no longer detects the first sheet S is longer than the time from when the width detection sensor SS2 detects the first sheet S to when it no longer detects the first sheet S.

[0072] Specifically, the control unit 100 sets the shape determination flag FL to 0 if the first sheet detection time td1, which is the time from when the trailing end detection sensor SS1 outputs an ON signal to when it outputs an OFF signal, is longer than the second sheet detection time td2, which is the time from when the width detection sensor SS2 outputs an ON signal to when it outputs an OFF signal.

[0073] Here, the sheet S that does not have a predetermined shape refers to a sheet S with a special shape in which the length in the transport direction of the portion detectable by the trailing end detection sensor SS1 is longer than the length in the transport direction of the portion detectable by the width detection sensor SS2, as shown in Fig. 6(a). In the case of such a sheet S, the first sheet detection time td1 is longer than the second sheet detection time td2. Here, the length of the first sheet detection time td1 and the second sheet detection time td2 include the length when the detection errors of the sensors SS1 and SS2 are added or subtracted.

[0074] As shown in (b) of FIG. 4 to FIG. 6, the control unit 100 controls the pickup roller 11A to supply the second sheet S (S2) at the timing when the trailing end detection sensor SS1 no longer detects the first sheet S. Specifically, the control unit 100 rotates the pickup roller 11A at the timing when the signal output from the trailing end detection sensor SS1 switches from an OFF signal to an ON signal, and supplies the second sheet S toward the transfer unit 50. In this case, the interval between the first sheet S (S1) and the second sheet S (S2) is B1. B1 is approximately equal to the distance in the transport direction from the nip portion between the pickup roller 11A and the retard roller 11B arranged thereon to the trailing end detection sensor SS1.

[0075] The control unit 100 controls the pickup roller 11A to supply the third sheet S (S3) at a timing based on the result of the shape determination process.

[0076] 5 and 6(c), when the shape determination process determines that the first sheet S (S1) does not have a predetermined shape, the control unit 100 controls the pickup roller 11A to supply the third sheet S (S3) at the timing when the trailing end detection sensor SS1 no longer detects the second sheet S (S2). Specifically, when the shape determination flag FL is 0, the control unit 100 rotates the pickup roller 11A at the timing when the signal output from the trailing end detection sensor SS1 switches from an OFF signal to an ON signal, and supplies the third sheet S (S3) toward the transfer unit 50. In this case, the interval between the second sheet S (S2) and the third sheet S (S3) is B1.

[0077] On the other hand, as shown in FIG. 4(c), when the shape determination process determines that the first sheet S (S1) has a predetermined shape, the control unit 100 controls the pickup roller 11A to supply the third sheet S (S3) at the timing when the width detection sensor SS2 no longer detects the second sheet S (S2). Specifically, when the shape determination flag FL is 1, the control unit 100 rotates the pickup roller 11A at the timing when the signal output from the width detection sensor SS2 switches from an ON signal to an OFF signal, and supplies the third sheet S (S3) toward the transfer unit 50. In this case, the interval between the second sheet S (S2) and the third sheet S (S3) is B2, which is shorter than B1. B2 is approximately equal to the distance from the nip portion between the pickup roller 11A and the retard roller 11B in the conveying direction to the width detection sensor SS2.

[0078] Furthermore, as shown in Fig. 5 and Fig. 6(d), in the case where foil is transferred to four or more sheets S in succession, if the first sheet S (S1) does not have the predetermined shape as a result of the shape determination process, the control unit 100 supplies the fourth and subsequent sheets S (S4) at the timing when the trailing end detection sensor SS1 no longer detects the preceding sheet S (S3). Specifically, when the shape determination flag FL is 0, the control unit 100 rotates the pickup roller 11A at the timing when the signal output from the trailing end detection sensor SS1 switches from an ON signal to an OFF signal, and supplies the fourth and subsequent sheets S sequentially toward the transfer unit 50. In this case, the interval between the preceding sheet S (S3) and the next sheet S (S4) is B1.

[0079] 4(d), when four or more sheets S (S4) are continuously supplied, if the shape determination process determines that the first sheet S (S1) has a predetermined shape, the control unit 100 supplies the fourth and subsequent sheets S (S4) at the timing when the width detection sensor SS2 no longer detects the preceding sheet S (S3). Specifically, when the shape determination flag FL is 1, the control unit 100 drives the pickup roller 11A at the timing when the signal output from the width detection sensor SS2 switches from an OFF signal to an ON signal, and supplies the fourth and subsequent sheets S sequentially toward the transfer unit 50. In this case, the interval between the preceding sheet S (S3) and the next sheet S (S4) is B2, which is shorter than B1.

[0080] Next, an example of the operation of the control unit 100 will be described with reference to the flowcharts shown in FIGS. 7, when the control unit 100 receives a command to start foil transfer, it executes a foil transfer preparation process (S11). After the foil transfer preparation process is completed, the control unit 100 rotates the pickup roller 11A to feed the sheet S (first sheet) toward the transfer unit 50 (S12).

[0081] After that, the control unit 100 executes a shape determination process (S20). As shown in Fig. 8, in the shape determination process, when the trailing end detection sensor SS1 outputs an ON signal due to the conveyance of the sheet S (S21, Yes), and then the trailing end detection sensor SS1 outputs an OFF signal (S22, Yes), the control unit 100 determines the shape of the sheet S (first sheet).

[0082] Specifically, the control unit 100 determines whether the width detection sensor SS2 has not detected the sheet S (S23). If the width detection sensor SS2 has not detected the sheet S (S23, Yes), the sheet S does not have a predetermined shape, for example, the sheet S is a narrow sheet S (see FIG. 5), so the control unit 100 sets the shape determination flag FL to 0 (S26).

[0083] In step S23, if the width detection sensor SS2 detects the sheet S (No), the control unit 100 judges whether the first sheet detection time td1 of the trailing edge detection sensor SS1 is longer than the second sheet detection time td2 of the width detection sensor SS2 (S24). If the first sheet detection time td1 is longer than the second sheet detection time td2 (S24, Yes), the sheet S does not have a predetermined shape, for example, it is a specially shaped sheet S (see FIG. 6), so the control unit 100 sets the shape determination flag FL to 0 (S26).

[0084] In step S24, if the first sheet detection time td1 is not longer than the second sheet detection time td2 (No), the control unit 100 determines whether the first sheet detection time td1 of the trailing edge detection sensor SS1 is the same as the second sheet detection time td2 of the width detection sensor SS2 (S25). If the first sheet detection time td1 and the second sheet detection time td2 are not the same (S25, No), the sheet S does not have a predetermined shape, so the control unit 100 sets the shape determination flag FL to 0 (S26).

[0085] In step S25, if the first sheet detection time td1 and the second sheet detection time td2 are the same (Yes), the sheet S has a predetermined shape, for example, a wide sheet S (see FIG. 4), so the control unit 100 sets the shape determination flag FL to 1 (S27).

[0086] 7, and determines whether the set detection sensor SS3 outputs an ON signal (S31). If the set detection sensor SS3 outputs an ON signal (S31, Yes), the next sheet S is placed on the sheet tray 3, so the control unit 100 rotates the pickup roller 11A to supply the next sheet S (second sheet) toward the transfer unit 50 (S32).

[0087] Thereafter, the control unit 100 determines whether or not the trailing end detection sensor SS1 outputs an ON signal due to the conveyance of the second sheet S (S41). If the trailing end detection sensor SS1 outputs an ON signal (S41, Yes), the control unit 100 determines whether or not the determination flag is 1 (S42).

[0088] If the determination flag is 1 (S42, Yes), that is, if the sheet S has a predetermined shape, the control unit 100 determines whether or not the width detection sensor SS2 has output an OFF signal due to the conveyance of the second sheet S (S43), and if an OFF signal has been output (S43, Yes), proceeds to the process of step S45. Also, if the determination flag is 0 (No) in step S42, that is, if the sheet S does not have a predetermined shape, the control unit 100 determines whether or not the trailing end detection sensor SS1 has output an OFF signal due to the conveyance of the second sheet S (S44), and if an OFF signal has been output (S44, Yes), proceeds to the process of step S45.

[0089] In step S45, the control unit 100 determines whether the set detection sensor SS3 outputs an ON signal. If the set detection sensor SS3 outputs an ON signal (S45, Yes), the next sheet S is placed on the sheet tray 3, so the control unit 100 rotates the pickup roller 11A to supply the next sheet S (third sheet) toward the transfer unit 50 (S46). Thereafter, the control unit 100 returns to the process of step S41.

[0090] If there is a fourth or subsequent sheet S in the sheet tray 3, the control unit 100 supplies the fourth or subsequent sheet S when the width detection sensor SS2 outputs an OFF signal if the sheet S has a specified shape, and supplies the fourth or subsequent sheet S when the trailing end detection sensor SS1 outputs an OFF signal if the sheet S does not have the specified shape (S41 to S46).

[0091] In steps S31 and S45, if the set detection sensor SS3 outputs an OFF signal (No), the sheet S is not placed on the sheet tray 3, so the control unit 100 determines whether or not a predetermined time tp has elapsed since the discharge sensor SS4 output an OFF signal (S51). Here, the predetermined time tp is set to a time at which it can be determined that the sheet S conveyed by the discharge roller 12B has been discharged outside the housing 2.

[0092] In step S51, if the predetermined time tp has elapsed (Yes), the last sheet S has been discharged outside the housing 2, so the control unit 100 executes a foil transfer end process (S52). In the foil transfer end process, the control unit 100, for example, controls the heater H of the heating roller 61 to lower the temperature of the transfer unit 50, controls the pressure contact / separation mechanism 70 to move the heating roller 61 to a separation position away from the pressure roller 51, and stops the rotation of the rollers 11B, 11C, 51, 12A, and 12B. After the foil transfer end process is completed, the control unit 100 ends the process.

[0093] 4, when the first sheet S (S1) has a predetermined shape, the third sheet S (S3) is supplied at the timing when the width detection sensor SS2, which is disposed upstream of the trailing end detection sensor SS1 in the conveying direction, no longer detects the second sheet S (S2), so that the interval B2 between the second sheet S (S2) and the third sheet S (S3) can be made shorter than the interval B1 in the case where the sheet S is supplied at the timing when the trailing end detection sensor SS1 no longer detects the sheet S. This makes it possible to shorten the printing time when foil is transferred continuously to multiple sheets S and to reduce waste of the foil film F.

[0094] Also, for the fourth and subsequent sheets S (S4), if the first sheet S (S1) has a predetermined shape, the sheet S (S4) is fed when the width detection sensor SS2 no longer detects the preceding sheet S (S3), so the interval B2 between the third and subsequent sheets S and the preceding sheet S can be shortened. This makes it possible to further shorten the printing time when foil is transferred to multiple sheets S in succession, and to further reduce waste of foil film F.

[0095] Although the embodiment has been described above, the present invention is not limited to the above embodiment, and can be modified as appropriate as exemplified below.

[0096] For example, in order to determine that a wide rectangular sheet S, such as an A4-sized sheet S, has a specified shape, the following second condition may be added to the first condition that the first sheet detection time td1 and the second sheet detection time td2 are the same, and if both the first and second conditions are satisfied, the first sheet S may be determined to have the specified shape.

[0097] The second condition can be a condition that the time it takes for the leading edge of the rectangular wide sheet S to move from the position detected by the width detection sensor SS2 to the position detected by the trailing edge detection sensor SS1 is defined as a first movement time, and the trailing edge detection sensor SS1 detects the first sheet S after the first movement time has elapsed since the width detection sensor SS2 detected the first sheet S. Alternatively, the second condition can be a condition that the time it takes for the trailing edge of the rectangular wide sheet S to move from the position detected by the width detection sensor SS2 to the position detected by the trailing edge detection sensor SS1 is defined as a second movement time, and the trailing edge detection sensor SS1 stops detecting the first sheet S after the second movement time has elapsed since the width detection sensor SS2 stopped detecting the first sheet S.

[0098] In addition, in the above embodiment, in the width direction, the trailing end detection sensor SS1 (first sheet sensor) is arranged at a position closer to the center of the transfer unit 50 than the end, and the width detection sensor SS2 (second sheet sensor) is arranged at a position farther from the center of the transfer unit 50 than the trailing end detection sensor SS1, but this is not limited to this. For example, in a configuration in which the foil transfer device conveys the sheet while shifting it to one side in the width direction of the transfer unit, the first sheet sensor may be arranged at a position farther from the center of the transfer unit than the second sheet sensor, and the second sheet sensor may be arranged at a position closer to the center than the end of the transfer unit.

[0099] In the above embodiment, the pressure contact / separation mechanism 70 moves the heating roller 61 relative to the pressure roller 51, but is not limited thereto, and may move the pressure roller relative to the heating roller, for example. Also, the transfer unit may not have a pressure contact / separation mechanism.

[0100] In addition, in the above embodiment, the pickup roller 11A is exemplified as the supply roller, but the present invention is not limited to this. For example, the supply roller may be composed of a pair of rollers.

[0101] In the above embodiment, the sensors SS1 to SS4 for detecting the sheet S are exemplified by sensors each including a lever and an optical sensor for detecting the position of the lever, but are not limited thereto. For example, the sensors may be composed of only an optical sensor.

[0102] In addition, in the above embodiment, the foil transfer device 1 that transfers foil to a toner image on the sheet S has been exemplified, but the present invention is not limited to this. The foil transfer device may be any device that transfers foil to a sheet.

[0103] In addition, in the above embodiment, the foil film F having four layers is exemplified, but the present invention is not limited to this, and the foil film may have any number of layers.

[0104] In the above embodiment, the sheet supply device 11 is applied to the foil transfer device 1, but the present invention is not limited thereto. For example, the sheet supply device may be applied to an image forming device such as a laser printer, an inkjet printer, or a dot impact printer. In this case, the image forming device includes an image forming unit that forms an image on a sheet as a sheet processing unit. The sheet supply device may be applied to a document reading device that includes an automatic document feeder. In this case, the document reading device includes a document reading unit that reads an image of a sheet (document) as a sheet processing unit. The sheet supply device may be applied to an image forming device that includes a document reading device, such as a copier or a multifunction device.

[0105] Furthermore, the elements described in the above embodiment and modified examples may be implemented in any combination. [Explanation of symbols]

[0106] 1 Foil transfer device 11 Sheet supply device 11A Pickup roller 50 Transcription unit 100 Control section F foil film S Seat SS1 Rear end detection sensor SS2 Width detection sensor

Claims

1. a feed roller that feeds a sheet toward a sheet processing portion that forms an image on the sheet, or feeds a sheet toward a sheet processing portion that reads the image on the sheet; a first sheet sensor that detects a sheet being fed toward the sheet processing section; a second sheet sensor that detects a sheet supplied toward the sheet processing section, the second sheet sensor being disposed upstream of the first sheet sensor in a sheet transport direction and at a position different from that of the first sheet sensor in a sheet width direction perpendicular to the transport direction; A control unit, the control unit is capable of executing a shape determination process for determining whether or not a shape of a sheet supplied to the sheet processing unit is rectangular and has a predetermined shape having a width that can be detected by both the first sheet sensor and the second sheet sensor, based on detection results of the first sheet sensor and the second sheet sensor; the first sheet sensor is disposed at a position capable of detecting a sheet being fed toward the sheet processing section regardless of whether the sheet has the predetermined shape; When a plurality of sheets are continuously fed, the control unit The first sheet is supplied at a predetermined timing by controlling the supply roller. After supplying the first sheet, the shape determination process is executed to determine whether the first sheet has the predetermined shape; The second sheet is supplied at a timing when the first sheet sensor no longer detects the first sheet by controlling the supply roller. The third sheet, If the result of the shape determination process indicates that the first sheet does not have the predetermined shape, the supply roller is controlled to supply the second sheet at a timing when the first sheet sensor no longer detects the second sheet; If the result of the shape determination process indicates that the first sheet has the predetermined shape, the supply roller is controlled to supply the second sheet at a timing when the second sheet sensor no longer detects the second sheet. A sheet supplying device comprising:

2. The sheet feeding device described in claim 1, characterized in that when four or more sheets are fed continuously, if the result of the shape determination process shows that the first sheet has the specified shape, the control unit feeds the fourth and subsequent sheets at a time when the second sheet sensor no longer detects the preceding sheet.

3. 3. The sheet feeding device according to claim 1, wherein the second sheet sensor is disposed at a position farther from a center of the sheet processing section in the width direction than the first sheet sensor.

4. 4. The sheet feeding device according to claim 1, wherein the first sheet sensor is disposed at a position closer to a center of the sheet processing section than to an end of the sheet processing section in the width direction.

5. A sheet supplying device as described in any one of claims 1 to 4, characterized in that, in the shape determination process, the control unit determines that the first sheet has the specified shape if the time when the first sheet sensor detects the first sheet is the same as the time when the second sheet sensor detects the first sheet.

6. A sheet supplying device as described in any one of claims 1 to 5, characterized in that, during the shape determination process, if the second sheet sensor does not detect the first sheet between the time when the first sheet sensor detects the first sheet and the time when the first sheet sensor no longer detects the first sheet, the control unit determines that the first sheet does not have the specified shape.

7. A sheet supplying device as described in any one of claims 1 to 6, characterized in that, in the shape determination process, the control unit determines that the first sheet does not have the specified shape if the time it takes the first sheet sensor to detect the first sheet is longer than the time it takes the second sheet sensor to detect the first sheet.

8. A foil transfer device that transfers the foil to a sheet by overlaying the sheet on a foil film including the foil, A transfer unit that transfers a foil onto a sheet as the sheet processing unit; A foil transfer apparatus comprising: the sheet supplying device according to claim 1 , which supplies a sheet to the transfer section.

Images