JP7619004B2 - Sheet supply device and foil transfer device - Google Patents

Description

The present invention relates to a sheet supply device and a foil transfer device.

Conventionally, a foil transfer device is known that includes a transfer unit that transfers foil onto a sheet, a feed roller that feeds the sheet toward the transfer unit, and a sheet sensor that detects the sheet being fed toward the transfer unit (see, for example, Patent Document 1).

JP 2020-122908 A

When multiple sheets are fed continuously, one method is to control the feed rollers so that the next sheet is fed when the sheet sensor no longer detects the preceding sheet. However, it is desirable to keep the gap between the preceding and following sheets as short as possible. If the gap between sheets is long, for example, the printing time will be longer when foil is transferred to multiple sheets in succession, or the foil film will be wasted if it is transported between the sheets.

Therefore, the present invention aims to provide a sheet supply device and foil transfer device that can shorten the distance between sheets.

In order to achieve the above-mentioned objective, the sheet feeding device includes a feed roller that feeds a sheet toward a sheet processing unit, which 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 unit, a second sheet sensor that detects the sheet fed toward the sheet processing unit, the second sheet sensor being positioned upstream of the first sheet sensor in the sheet transport direction and at a different position from the first sheet sensor in the sheet width direction perpendicular to the transport direction, and a control unit.
When a plurality of sheets are to be continuously fed, the control unit controls the feed roller to feed the first sheet at a predetermined timing.
After supplying the first sheet, the control unit executes a shape determination process to determine 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 the specified shape, the control unit controls the supply roller to supply the third sheet following the second sheet at the 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.

With this configuration, when the first sheet has a predetermined shape, the third sheet is supplied at the timing when the second sheet sensor, which is located upstream of the first sheet sensor in the conveying direction, no longer detects the second sheet, thereby shortening the distance between the second sheet and the third sheet.

In the above-mentioned sheet supplying device, when four or more sheets are supplied in succession, 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 timing when the second sheet sensor no longer detects the preceding sheet.

This allows the distance between the third and subsequent sheets and the preceding sheet to be shortened.

In the above-mentioned sheet supply device, the second sheet sensor can be configured to be positioned farther from the center of the sheet processing section in the width direction than the first sheet sensor.

In the above-mentioned sheet supplying device, the first sheet sensor can be configured to be positioned closer to the center of the sheet processing section in the width direction than to the edge of the sheet processing section.

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 at which the first sheet sensor detects the first sheet is the same as the time at which the second sheet sensor detects the first sheet.

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 the first sheet sensor no longer detects the first sheet.

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 the specified 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.

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 that transfers the foil to the sheet as a sheet processing unit, and the above-mentioned sheet supply device that supplies the sheet to the transfer unit.

This configuration allows the distance between the second sheet and the third sheet to be shortened. This makes it possible to reduce the printing speed when transferring foil to multiple sheets in succession and to reduce waste of foil film.

According to the present invention, the distance between the second sheet and the third sheet can be shortened.

1A is a diagram showing a foil transfer device including a sheet supplying device according to an embodiment, and FIG. 1B is a cross-sectional view showing the configuration of a foil film. FIG. 2 is a diagram showing the foil transfer device with the cover open. FIG. 4 is a diagram showing the arrangement of sensors for detecting a sheet. 1A to 1D are diagrams illustrating an example of the timing and intervals for supplying a first sheet when the first sheet has a predetermined shape. 10A to 10D are diagrams illustrating an example of the timing and intervals for supplying a first sheet when the first sheet does not have a predetermined shape. 13A to 13D are diagrams illustrating other examples of the sheet supply timing and intervals when the first sheet does not have a predetermined shape. 10 is a flowchart showing an example of an operation of a control unit. 13 is a flowchart illustrating an example of a shape determination process.

Next, one 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 terms of the directions shown in FIG. 1(a). That is, the right side of FIG. 1(a) will be referred to as the "front", the left side as the "rear", the front side of the page as the "left", and the back side of the page as the "right". Additionally, the top and bottom of FIG. 1(a) will be referred to as the "top and bottom".

As shown in FIG. 1(a), the foil transfer device 1 is a device for overlaying a sheet S on a foil film F containing foil and transferring the foil to the sheet S. The foil transfer device 1 forms an image of foil on the sheet S by transferring a foil such as aluminum onto a toner image formed on the sheet S by an image forming device such as a laser printer. The 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.

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.
The cover 22 is a member for opening and closing the opening 21A. A rear end of the cover 22 is rotatably supported by the housing body 21. The cover 22 is rotatable between a closed position where the opening 21A is closed and an open position where the opening 21A is opened (see FIG. 2).

The sheet tray 3 is a tray on which sheets S, such as paper and overhead projector film, 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 down.

The sheet conveying section 10 includes a sheet supplying device 11 and a sheet discharging 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 transport roller 11C.

The pickup roller 11A is a roller for feeding the sheet S on the sheet tray 3 toward the transfer unit 50.

The retard roller 11B is a roller for separating the sheet S conveyed by the pickup roller 11A into a single 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.

The transport roller 11C is made up of a pair of rollers, and is capable of transporting the sheet S by rotating each roller while the sheet S is sandwiched between the pair of rollers. The transport roller 11C is disposed between the pickup roller 11A and the transfer unit 50, and transports the sheet S sent out by the pickup roller 11A to the transfer unit 50.

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 is equipped with intermediate discharge rollers 12A and discharge rollers 12B. Each of the intermediate discharge rollers 12A and discharge rollers 12B consists of a pair of rollers, and each roller rotates while the sheet S is sandwiched between the pair of rollers, thereby enabling the sheet S to be transported.

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."

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

The film supply unit 30 supplies the foil film F so that it is superimposed on the sheet S transported from the sheet supply device 11. The film supply unit 30 includes a film unit FU and a motor 80.

As shown in FIG. 2, the film unit FU can be attached to and detached from the top of the housing 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. The foil film F is wound around the supply reel 31 of the film unit FU.

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.

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.

The transfer layer F22 is a layer to be transferred to the toner image and contains foil. The foil is a thin metal such as gold, silver, copper, or aluminum. The transfer layer F22 also contains 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.

The adhesive layer F23 is a layer that facilitates adhesion of the transfer layer F22 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.

1A, 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.

1(a) and other figures show, for convenience, the foil film F wound to its maximum on 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 of foil film F wound on the supply reel 31 is maximum, and the take-up reel 35 has no foil film F wound thereon, or the diameter of the roll of foil film F wound on the take-up reel 35 is minimum. At the end of the film unit FU's life (when the foil film F has been used up), the diameter of the roll of foil film F wound on the take-up reel 35 is maximum, and the supply reel 31 has no foil film F wound thereon, or the diameter of the roll of foil film F wound on the supply reel 31 is minimum.

The first guide shaft 41, the second guide shaft 42, and the third guide shaft 43 are roller-shaped shafts for changing the direction of travel 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.

The first guide shaft 41 is located upstream of the transfer section 50 in the transport 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 transport direction of the sheet S. The foil film F guided by the first guide shaft 41 is transported toward the transfer section 50 with the supported layer F2 (see FIG. 1(b)) facing up. In addition, the sheet S is placed on top of the foil film F with the supported layer F2 facing up, and is transported together with the foil film F toward the transfer section 50.

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.

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 it 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 that is guided by the second guide shaft 42 and guides it to the take-up reel 35.

With the film unit FU attached to the foil transfer device 1, the take-up reel 35 is driven to rotate counterclockwise as shown by the 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 onto 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 onto the take-up reel 35.

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, forming a foil image 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.

The pressure roller 51 is a roller in which the circumference of a cylindrical core metal is covered with a rubber layer made of silicone rubber. The pressure roller 51 is placed on the upper side of the foil film F and can come into contact with 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 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.

The heating roller 61 is a roller with a heater H 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.

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 pressed against 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 phantom line in FIG. 1. In this embodiment, the pressure contact position is the position where the heating roller 61 is pressed against the pressure roller 51, and the spaced position is the position where the heating roller 61 is spaced from the pressure roller 51.

In the foil transfer device 1 configured in this manner, the sheets S placed on the sheet tray 3 with their front surfaces facing down 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.

In the transfer section 50, when 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.

After the foil is transferred, the sheet S and foil film F are transported in a bonded state to the second guide shaft 42. When the sheet S and 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, i.e., the supported layer F2 adhered to the toner image is peeled off from the support layer F1 of the foil film F.

The foil film F, which is peeled off from the sheet S and includes the support layer F1 peeled off from the supported layer F2 adhered to the toner image on the sheet S, is wound up on 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.

As shown in FIG. 3, the sheet supplying device 11 further includes a trailing edge 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.

The trailing edge 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 a 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.

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

The trailing edge 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.

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

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

The width detection sensor SS2 is disposed upstream of the trailing end detection sensor SS1 in the transport direction. Furthermore, the width detection sensor SS2 is disposed at a different position in the width direction from the trailing end detection sensor SS1. 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.

In this embodiment, the foil transfer device 1 is configured to transport sheets S of standard sizes such as letter size, A4 size, and 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 positioned in a position in the width direction where it can detect sheets S with widths equal to or larger than A5 size, but cannot detect sheets S with widths equal to or smaller than A6 size.

The set detection sensor SS3 is disposed upstream of the trailing 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 of the center C of the heating roller 61 in the width direction.

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 closer to the center of the transfer unit 50 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.

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 moment when the signal output to the control unit 100 switches from an OFF signal to an ON signal is the moment when the sheet S is detected, and the moment when the signal output to the control unit 100 switches from an ON signal to an OFF signal is the moment when the sheet S is no longer detected.

The control unit 100 (see FIG. 1(a)) is equipped with a CPU, RAM, ROM, input/output circuits, etc., and performs various arithmetic operations based on programs and data stored in the ROM, etc., to execute control.

In this embodiment, when the control unit 100 continuously supplies multiple sheets S placed on the sheet tray 3, it 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 Figures 4 to 6, which will 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".

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, it 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 the 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, when the foil transfer preparation process is completed, the control unit 100 rotates the pickup roller 11A and supplies the first sheet S toward the transfer unit 50.

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 edge 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 subsequent sheets S, assuming that a sheet S of the same shape as the first sheet S is placed on the sheet tray 3.

In the shape determination process, 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, the control unit 100 determines that the first sheet S has a predetermined shape. In this embodiment, in the shape determination process, 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, the control unit 100 determines that the first sheet S has a predetermined shape.

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 edge 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.

In this embodiment, a 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 edge detection sensor SS1 and the width detection sensor SS2, as shown in FIG. 4(a). As an example, a 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 each sensor SS1, SS2 have been added or subtracted.

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

Here, a sheet S that does not have a specified shape is, for example, as shown in FIG. 5(a), 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 an example, a sheet S that does not have a specified shape is a sheet S with 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 between the time when the trailing end detection sensor SS1 outputs an ON signal and the time when it outputs an OFF signal.

In addition, in the shape determination process, if the time taken for the trailing end detection sensor SS1 to detect the first sheet S is longer than the time taken for the width detection sensor SS2 to detect the first sheet S, the control unit 100 determines that the first sheet S does not have the specified shape. In this embodiment, in the shape determination process, if the time taken for the trailing end detection sensor SS1 to detect the first sheet S and then stop detecting the first sheet S is longer than the time taken for the width detection sensor SS2 to detect the first sheet S and then stop detecting the first sheet S, the control unit 100 determines that the first sheet S does not have the specified shape.

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 edge 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.

Here, a sheet S that is not of a specified shape refers to a sheet S of a special shape in which the length in the transport direction of the portion detectable by the trailing edge 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 includes the length when the detection errors of each sensor SS1, SS2 are added or subtracted.

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 edge 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 edge 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 from the nip between the pickup roller 11A and the retard roller 11B arranged above it in the conveying direction to the trailing edge detection sensor SS1.

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

More specifically, as shown in FIG. 5 and FIG. 6(c), when the shape determination process determines that the first sheet S (S1) does not have the predetermined shape, the control unit 100 controls the pickup roller 11A to supply the third sheet S (S3) at the timing when the trailing edge 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 edge 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.

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 between the pickup roller 11A and the retard roller 11B in the conveying direction to the width detection sensor SS2.

Furthermore, as shown in FIG. 5 and FIG. 6(d), when foil is transferred continuously onto four or more sheets S, if the shape determination process results in the first sheet S (S1) not being of the predetermined shape, the control unit 100 supplies the fourth and subsequent sheets S (S4) at the timing when the trailing edge 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 edge 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.

In addition, as shown in FIG. 4(d), when four or more sheets S (S4) are supplied in succession, if the shape determination process results in the first sheet S (S1) being of 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.

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, the control unit 100 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).

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

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, it is a narrow sheet S (see FIG. 5), so the control unit 100 sets the shape determination flag FL to 0 (S26).

In step S23, if the width detection sensor SS2 detects the sheet S (No), the control unit 100 determines 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 sheet S with a special shape (see FIG. 6), so the control unit 100 sets the shape determination flag FL to 0 (S26).

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 and the second sheet detection time td2 of the width detection sensor SS2 are the same (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 the specified shape, so the control unit 100 sets the shape determination flag FL to 0 (S26).

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).

After determining the shape of the sheet S, the control unit 100 returns to the process of FIG. 7 and determines whether the set detection sensor SS3 is outputting an ON signal (S31). If the set detection sensor SS3 is outputting an ON signal (S31, Yes), the next sheet S is placed on the sheet tray 3, and the control unit 100 rotates the pickup roller 11A to supply the next sheet S (second sheet) toward the transfer unit 50 (S32).

Then, the control unit 100 determines whether the trailing edge detection sensor SS1 outputs an ON signal due to the transport of the second sheet S (S41). If the trailing edge detection sensor SS1 outputs an ON signal (S41, Yes), the control unit 100 determines whether the determination flag is 1 (S42).

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

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

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 predetermined shape, and supplies the fourth or subsequent sheet S when the trailing edge detection sensor SS1 outputs an OFF signal if the sheet S does not have the predetermined shape (S41 to S46).

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 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 being transported by the discharge roller 12B has been discharged outside the housing 2.

In step S51, if the predetermined time tp has elapsed (Yes), the last sheet S has been discharged outside the housing 2, and the control unit 100 executes the 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 each of the rollers 11B, 11C, 51, 12A, and 12B. After the foil transfer end process is completed, the control unit 100 ends the process.

According to the present embodiment described above, as shown in FIG. 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 arranged upstream in the conveying direction from the trailing end detection sensor SS1, no longer detects the second sheet S (S2). Therefore, the interval B2 between the second sheet S (S2) and the third sheet S (S3) can be made shorter than the interval B1 when 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 reduce waste of foil film F.

In addition, 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 shorten the printing time when foil is transferred to multiple sheets S in succession, and to reduce waste of foil film F.

Although the embodiment has been described above, the present invention is not limited to the above embodiment, and can be modified as appropriate as shown in the following examples.

For example, to determine that a wide rectangular sheet S, such as an A4-sized sheet S, has a predetermined 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 predetermined shape.

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 no longer detects the first sheet S after the second movement time has elapsed since the width detection sensor SS2 no longer detects the first sheet S.

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

In addition, in the above embodiment, the pressure contact/separation mechanism 70 is configured to move the heating roller 61 relative to the pressure roller 51, but this is not limited thereto, and for example, the pressure roller may be configured to move relative to the heating roller. Also, the transfer unit may be configured not to include a pressure contact/separation mechanism.

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

In the above embodiment, the sensors SS1 to SS4 that detect the sheet S are exemplified as sensors each consisting of a lever and an optical sensor that detects the position of the lever, but this is not limiting. For example, the sensors may consist of only an optical sensor.

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

In addition, in the above embodiment, a foil film F having four layers is exemplified, but this is not limited thereto, and the foil film may have any number of layers.

In the above embodiment, the sheet supply device 11 is applied to the foil transfer device 1, but the present invention is not limited to this. 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 multifunction device.

Furthermore, the elements described in the above embodiments and variations may be implemented in any combination.

REFERENCE SIGNS LIST 1 foil transfer device 11 sheet supply device 11A pickup roller 50 transfer unit 100 control unit F foil film S sheet SS1 trailing end detection sensor SS2 width detection sensor

Claims (8)

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;
a sheet supplying device that, when the result of the shape determination process indicates that the first sheet has the predetermined shape, controls the supply roller to supply the second sheet at a timing when the second sheet sensor no longer detects the second sheet. The sheet feeding device according to claim 1, characterized in that, when four or more sheets are fed continuously, if the result of the shape determination process is that the first sheet has the specified shape, the control unit feeds the fourth and subsequent sheets at a timing when the second sheet sensor no longer detects the preceding sheets. The sheet feeder according to claim 1 or 2, characterized in that the second sheet sensor is disposed at a position farther from the center of the sheet processing section in the width direction than the first sheet sensor. The sheet feeder according to any one of claims 1 to 3, characterized in that the first sheet sensor is disposed at a position closer to the center of the sheet processing section in the width direction than to the end of the sheet processing section. The sheet supplying device of 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 when 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. The sheet supplying device of 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. The sheet supplying device according to 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 for the first sheet sensor to detect the first sheet is longer than the time it takes for the second sheet sensor to detect the first sheet. 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.

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