Patent Description:
A sheet separation device (i.e. a laminator) separates a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet (for example, see PTL1 (<CIT>)). Specifically, the laminator in PTL1 includes the sheet separation device that separates two sheets of a laminated sheet that is a two-ply sheet in which one sides of the two sheets are bonded, and inserts protective paper that is an insertion sheet therebetween.

In a technique disclosed in PTL1, one suction device sucks one of the two sheets of the laminated sheet (that is the two-ply sheet) in which the one sides of the two sheets are bonded, and the other suction device sucks the other sheet of the two sheets. As a result, two sheets are separated.

Conventional sheet separation devices are large and expensive because the sheet separation devices use large devices such as two suction devices to separate two sheets constituting a two-ply sheet.

This disclosure is made in light of solving the above-described problems, and an object of this disclosure is to provide a sheet separation device, a laminator, an image forming apparatus, and an image forming system, which can preferably separate two sheets constituting the two-ply sheet without increasing the size of the separation device.

Embodiments of this disclosure can provide a sheet separation device, a laminator, an image forming apparatus, and an image forming system, which can preferably separate two sheets constituting a two-ply sheet without increasing the size of the sheet separation device.

The accompanying drawings are intended to depict example embodiments of the present invention and should not be interpreted to limit the scope thereof, which is only defined by the appended claims.

With reference to the drawings, embodiments of the present disclosure are described below. Identical reference numerals are assigned to identical components or equivalents and a description of those components is simplified or omitted.

A configuration and operations of a sheet separation device <NUM> are described below with reference to <FIG>.

The sheet separation device <NUM> separates a non-bonding portion of a two-ply sheet PJ in which two sheets P1 and P2 are overlapped and bonded together at a bonding portion A (see <FIG>) of the two-ply sheet. The two-ply sheet PJ in the present embodiment is made of two sheets P1 and P2 overlapped and bonded together at one side of four sides as the bonding portion A. That is, in the two-ply sheet PJ made of two sheets P1 and P2, only one sides of the two sheets P1 and P2 are connected by thermal welding or the like as the bonding portion A, and the other sides of the two sheets P1 and P2 are overlapped and not connected as non-bonding portions. As the two sheets P1 and P2 constituting the two-ply sheet PJ, a transparent film sheet (that is, a laminate sheet) may be used.

The two-ply sheet PJ may be made by folding a single sheet. In the present disclosure, the two-ply sheet PJ made by folding a single sheet is also defined as the two sheets overlapped, a folded portion of the folded single sheet is defined as the bonding portion, and the other portions are defined as the non-bonding portions.

Between the winding roller <NUM> and the third conveyance roller pair <NUM>, the sheet separation device <NUM> separates the two sheets P1 and P2 constituting the two-ply sheet PJ at the non-bonding portion. The sheet separation device <NUM> separates the two sheets P1 and P2 around the bonding portion A that maintains bonding the two sheets P1 and P2. Subsequently, the sheet separation device <NUM> inserts an insertion sheet PM between the separated two sheets P1 and P2. The insertion sheet PM is a sheet such as one plain sheet.

As illustrated in <FIG>, the sheet separation device <NUM> includes a first feed tray <NUM>, a second feed tray <NUM>, a first feed roller <NUM>, a second feed roller <NUM>, a first conveyance roller pair <NUM>, a second conveyance roller pair <NUM>, a third conveyance roller pair <NUM>, an ejection tray <NUM>, a first sensor <NUM>, a second sensor <NUM>, a third sensor <NUM>, a fourth sensor <NUM>, a fifth sensor <NUM>, a winding roller <NUM>, a moving mechanism <NUM>, a switching claw <NUM>, separation claws <NUM>, a first guide <NUM> as an inner limiter, a second guide <NUM> as an outer limiter, and a third guide <NUM>. Additionally, the sheet separation device <NUM> includes a plurality of conveyance paths such as a first conveyance path K1, a second conveyance path K2, a third conveyance path K3, a first branched conveyance path K4, and a second branched conveyance path K5. The above-described conveyance paths K1 to K5 each include two conveyance guides (that are guide plates) facing each other to guide and convey the sheet such as the two-ply sheet PJ or the insertion sheet PM.

Specifically, the two-ply sheet PJ is stacked on the first feed tray <NUM>. The first feed roller <NUM> feeds the uppermost two-ply sheet PJ on the first feed tray <NUM> to the first conveyance roller pair <NUM>, and the first conveyance roller pair <NUM> conveys the two-ply sheet PJ along the first conveyance path K1.

The insertion sheet PM is stacked on the second feed tray <NUM>. The second feed roller <NUM> feeds the uppermost insertion sheet PM on the second feed tray <NUM> to the second conveyance path K2.

Each of the first to third conveyance roller pairs <NUM> to <NUM> includes a drive roller and a driven roller each having an elastic layer made of rubber or the like formed on a core, and conveys the sheet nipped in a nip between the drive roller and the driven roller. The third conveyance path K3 is a path from the second conveyance roller pair <NUM> to the third conveyance roller pair <NUM> and includes, from the upstream side, the second conveyance roller pair <NUM>, the winding roller <NUM>, and the third conveyance roller pair <NUM>. The third conveyance roller pair <NUM> is configured to be able to rotate in forward or in reverse, rotates in forward to convey the sheet in forward, and rotates in reverse to convey the sheet in reverse. The third conveyance roller pair <NUM> also functions as an ejection roller pair that ejects the sheet to the ejection tray <NUM>.

Each of the first to fifth sensors <NUM> to <NUM> is a reflective photosensor that optically detects whether the sheet is present at the position of each sensor. The first sensor <NUM> is disposed in the vicinity of the downstream side of the first conveyance roller pair <NUM>. The second sensor <NUM> is disposed in the vicinity of the downstream side of the second feed roller <NUM>. The third sensor <NUM> is disposed between the second conveyance roller pair <NUM> and the winding roller <NUM> in the vicinity of the downstream side of the second conveyance roller pair <NUM>. The fourth sensor <NUM> serving as a sheet detection sensor is disposed upstream the third conveyance roller pair <NUM> in the vicinity of the downstream side of the winding roller <NUM>. The fifth sensor <NUM> is disposed downstream the third conveyance roller pair <NUM>.

The winding roller <NUM> is described below with reference to <FIG>, <FIG>, and <FIG>, (and <FIG> and <FIG>).

In the winding roller <NUM>, a gripper <NUM> that is one example of a gripper grips a gripped portion B of the two-ply sheet PJ at a winding start position W. The gripped portion B is one end of the two-ply sheet PJ that is opposite an end at which the bonding portion A is formed. While the gripper <NUM> grips the gripped portion B of the two-ply sheet PJ, the winding roller <NUM> rotates in a predetermined rotation direction to wrap the two-ply sheet PJ around the winding roller <NUM>. The winding roller <NUM> can rotate about a rotation shaft 20a in forward and in reverse.

A controller controls a drive motor that drives the winding roller <NUM>. The controller includes one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), and conventional circuit components.

Specifically, as illustrated in <FIG>, the two-ply sheet PJ starts from the first feed tray <NUM> and passes through the first conveyance path K1, and the second conveyance roller pair <NUM> conveys the two-ply sheet PJ in the forward direction along the third conveyance path K3. The two-ply sheet passes through a position of the winding roller <NUM> once and is conveyed to a position of the third conveyance roller pair <NUM>. Thereafter, the third conveyance roller pair <NUM> rotates in reverse to convey the two-ply sheet PJ to the position of the winding roller <NUM>. The gripper <NUM> grips the two-ply sheet PJ and the winding roller <NUM> rotates counterclockwise to wrap the two-ply sheet PJ around the winding roller <NUM>.

With reference to <FIG>, the linear velocity of the sheet P1 and the linear velocity of sheet P2 each are proportional to a distance from the center of the winding roller <NUM> to each of the sheets P1 and P2 like the linear velocity of the roller surface that is proportional to the radius of the roller when the two-ply sheet PJ is wrapped around the winding roller <NUM>. Therefore, the linear velocity of the sheet P1 is slower than the linear velocity of the sheet P2 because the sheet P1 is nearer from the center of the winding roller <NUM> than the sheet P2. The slower sheet P1 that is referred to as a first sheet P1 is more likely to slacken than the sheet P2 that is referred to as a second sheet P2. As illustrated in <FIG> and <FIG>, the upper first sheet P1 is bent upward and forms a gap C between the two sheets P1 and P2 in the vicinity of the bonding portion A that is referred to as the other end of the two-ply sheet PJ. As described above, the two sheets P1 and P2 that are in close contact with each other without any gap are separated from each other.

The following additionally describes a mechanism that winding the two-ply sheet PJ around the winding roller <NUM> generates the gap C in the two-ply sheet PJ between the winding roller <NUM> and the third conveyance roller pair <NUM>.

In the two-ply sheet PJ wound around the winding roller <NUM>, the gripped portion B of the two-ply sheet PJ gripped by the gripper <NUM> does not generate a slip between the sheets P1 and P2. However, winding the two-ply sheet PJ around the winding roller <NUM> generates the difference in winding circumferential length between the two sheets P1 and P2 and, therefore, causes a slip between the two sheets P1 and P2, and a conveyance amount of the inner sheet P1 is smaller than a conveyance amount of the outer sheet P2. As a result, slack occurs in the inner sheet P1 between the nip of the third conveyance roller pair <NUM> and the winding roller <NUM>. Winding the two-ply sheet PJ around the winding roller <NUM> one or more times additionally generates the difference in winding circumferential length between the inner circumference and the outer circumference by the thickness of the sheet and increases the slack. Finally, the slack is accumulated between the third conveyance roller pair <NUM> and the winding roller <NUM>, and the gap C is formed between the two sheets P1 and P2.

Specifically, a distance from the rotation shaft 20a (i.e. the center of the shaft) of the winding roller <NUM> to the outer sheet P2 is R + ΔR when a distance from the rotation shaft 20a (i.e. the center of the shaft) of the winding roller <NUM> to the inner sheet P1 is R, and the thickness of the inner sheet P1 is Δ R. The difference between a radius of the inner sheet P1 wound around the winding roller <NUM> and a radius of the outer sheet P2 wound around the inner sheet P1, that is, the thickness of the inner sheet P1 Δ R, generates a circumferential length difference of <NUM> × Δ R × π when the two-ply sheet PJ is wound around the winding roller <NUM> by one round. Therefore, winding the two-ply sheet PJ around the winding roller <NUM> times generates the circumferential length difference <NUM> × Δ R × π × M that is a slack of the inner sheet P1. Finally, the slack is accumulated between the third conveyance roller pair <NUM> and the winding roller <NUM>, and the gap C corresponding to <NUM> × Δ R × π × M is formed between the two sheets P1 and P2.

In the present embodiment, in order to significantly form the gap C as described above, the two-ply sheet PJ is wound around the winding roller <NUM> at least once or more. In the present embodiment, winding the two-ply sheet PJ around the winding roller <NUM> can separate the two-ply sheet PJ without increasing the size and cost of the sheet separation device <NUM>.

As illustrated in <FIG>, the gripper <NUM> in <FIG> is configured to grip the gripped portion B of the two-ply sheet PJ without abutting and contacting the end surface of the tip of one end of the gripped portion B.

The "end surface" of the two-ply sheet is defined as a side surface extending in the thickness direction and connecting the front surface and the back surface of the two-ply sheet. Accordingly, there are four end surfaces of the rectangular two-ply sheet on the front, back, left, and right.

Specifically, the gripper <NUM> is configured to sandwich and grip the gripped portion B of the two-ply sheet PJ in a direction perpendicular to the sheet surface of the gripped portion B of the two-ply sheet PJ between the gripper <NUM> and a receiving portion 20b of the winding roller <NUM> without causing any member to abut and restrict the end surface of the one end of the two-ply sheet PJ, in other words, without causing any member to hit or contact the end surface of the two-ply sheet PJ. The receiving portion 20b is disposed on the outer surface of the winding roller <NUM> and faces the gripper <NUM>. More specifically, the receiving portion 20b is disposed in a portion recessed inward from a virtual outer peripheral surface of the winding roller <NUM>. The virtual outer peripheral surface is an outer cylindrical surface around which the two-ply sheet PJ is wound.

More specifically, the two-ply sheet PJ is not gripped and sandwiched by the gripper <NUM> and the receiving portion 20b in a state in which a specific member such as the gripper <NUM> abuts on the end surface of the one end (that is the tip of one end) to restrict the end surface. Without abutting the end surface of the one end that is the tip of the one end to any member, the two-ply sheet PJ is sandwiched and gripped by the outer gripper <NUM> and the inner receiving portion 20b.

That is, the end surface of the one end (that is the tip of one end) of the two-ply sheet PJ does not abut against an obtuse angle portion (a wedge portion) of the gripper <NUM> in <FIG>, and the gripped portion B on the one end of the two-ply sheet PJ is gripped by the gripper <NUM> and the receiving portion 20b. Without abutting on any member, the end surface of the one end (that is the tip of one end) of the two-ply sheet PJ coincides with an end of a contact surface of the receiving portion 20b at which the gripper <NUM> contacts the receiving portion 20b via the two ply sheet PJ, that is, a right end of the contact surface in <FIG>.

The end surface of the one end (that is the tip of one end) of the two-ply sheet PJ may move to the right in <FIG> beyond the contact surface between the gripper <NUM> and the receiving portion 20b so that the gripped portion B is inside the sheet from the tip of the one end, that is, the other end side from the tip of the one end. Alternatively, the end surface of the one end (that is the tip of one end) may be on a left point of the contact surface from the right end of the contact surface in <FIG>.

Compared with a structure that abuts the end surface of the tip of the two-ply sheet on a member, the above-described structure can reduce a disadvantage that the two-ply sheet PJ (particularly, the tip of one end) is damaged.

In the present embodiment, the bonding portion A of the two-ply sheet PJ wound around the winding roller <NUM> is the other end of the two-ply sheet PJ. The other end is opposite to the one end serving as the gripped portion B.

In the present embodiment, at least one of the gripper <NUM> and the receiving portion 20b is made of elastic material such as rubber or includes an elastic part such as a spring, or a flat spring. Compared with a sheet separation device including the gripper <NUM> and the receiving portion 20b that are rigid bodies made of metal or resin, the above-described sheet separation device can increase a gripping force to grip the two-ply sheet PJ and prevent surfaces of the two-ply sheet PJ from being damaged. In particular, the sheet separation device including the gripper <NUM> and the receiving portion 20b made of the elastic material easily exhibits the above-described effect.

As illustrated in <FIG>, <FIG>, the moving mechanism <NUM> moves the gripper <NUM> at the winding start position W of the winding roller <NUM> between a gripping position (a position illustrated in <FIG> and <FIG>) at which the gripper <NUM> can grip the two-ply sheet PJ and a releasing position (a position illustrated in <FIG> and <FIG>) at which the gripper <NUM> is released from the gripping position.

Specifically, the moving mechanism <NUM> includes an arm <NUM>, a compression spring <NUM> as a biasing member, a cam <NUM>, and a motor that rotates the cam <NUM> in forward or in reverse. The arm <NUM> holds the gripper <NUM> and is held by the winding roller <NUM> to be rotatable about a support shaft 31a. In the present embodiment, the gripper <NUM> is connected to a base of the arm <NUM>, that is, the tip of arm <NUM>, and the gripper <NUM> and the arm <NUM> are made as one part. Alternatively, the gripper <NUM> and the arm <NUM> may be made as separate members, and the gripper <NUM> may be disposed on the arm <NUM>, that is, may be held by the arm <NUM>. In any case, the arm <NUM> holding the gripper <NUM> rotates around the rotation shaft 20a together with the gripper <NUM> and the winding roller <NUM>.

The compression spring <NUM> functions as a biasing member that biases the arm <NUM> so that the gripper <NUM> moves from the releasing position illustrated in <FIG> to the gripping position illustrated in <FIG>. Specifically, one end of the compression spring <NUM> is connected to a fixed part near the rotation shaft 20a, and the other end of the compression spring <NUM> is connected to one end of the arm <NUM> that is a free end opposite to the other end of the arm <NUM> connected to the gripper <NUM> with respect to the support shaft 31a.

The cam <NUM> pushes the arm <NUM> against the biasing force of the compression spring <NUM> as the biasing member so that the gripper <NUM> moves from the gripping position illustrated in <FIG> to the releasing position illustrated in <FIG>. A motor controlled by the controller drives the cam <NUM> to rotate in forward or in reverse at a desired rotation angle. The cam <NUM> is held by the apparatus housing so as to be rotatable about a cam shaft 34a independently of the winding roller <NUM>.

In the moving mechanism <NUM> configured as described above, as illustrated in <FIG> and <FIG>, the arm <NUM> not contacting the cam <NUM> is biased by the compression spring <NUM> and presses the gripper <NUM> against the receiving portion 20b. This state is referred to as a closed state. In contrast, as illustrated in <FIG> and <FIG>, the arm <NUM> pressed by the cam <NUM> rotates counterclockwise in <FIG> about the support shaft 31a against the urging force of the compression spring <NUM> and separates the gripper <NUM> from the receiving portion 20b. This state is referred to as an open state. In the open state, the two-ply sheet PJ is not gripped, which is referred to as a grip release state.

When the gripper <NUM> is at the releasing position to be in the open state, the two-ply sheet PJ enters a space between the gripper <NUM> and the receiving portion 20b, and the gripper <NUM> moves to the gripping position to be in the closed state. As a result, the gripper <NUM> and the receiving portion 20b grip the two-ply sheet PJ.

In the present embodiment, as illustrated in <FIG>, the winding roller <NUM> includes a plurality of roller portions (i.e. seven roller portions in the present embodiment) having a columnar shape and separated in the axial direction of the winding roller <NUM>. A plurality of grippers <NUM> and a plurality of arms <NUM> are disposed at recesses between adjacent roller portions (that are portions between roller portions), respectively. A plurality of cams <NUM> are disposed to be able to abut against the plurality of arms <NUM>, respectively.

Setting positions separated in the axial direction to grip the two-ply sheet PJ as described above, that is, not setting entire area in the axial direction to grip the two-ply sheet PJ can separate load necessary to grip the two-ply sheet PJ and be scratch resistant at the tip of one end of the two-ply sheet PJ. In addition, the above-described configuration is useful when a necessary gripping force becomes large, for example, when a large-sized two-ply sheet PJ or a heavy two-ply sheet PJ is gripped.

In this embodiment, as illustrated in <FIG>, the third conveyance path K3 is made of linear conveyance guide plates. In contrast, the third conveyance path may be made of curved conveyance guide plates. In such a case, a gripping position at which the winding roller <NUM> grips the two-ply sheet PJ may be changed to be closer to the rotation shaft 20a than the gripping position in the present embodiment. Additionally, in such a case, the positions of the gripper <NUM> and the receiving portion 20b in the present embodiment may be interchanged, that is, in the winding roller <NUM>, the gripper <NUM> may be disposed closer to the rotation shaft 20a than the receiving portion 20b.

With reference to <FIG>, <FIG>, and <FIG>, the following describes the fourth sensor <NUM> in the sheet separation device <NUM> in the present embodiment. The fourth sensor <NUM> is the sheet detection sensor to detect two-ply sheet PJ conveyed toward the winding roller <NUM>. Based on results detected by the fourth sensor <NUM> that is the sheet detection sensor, the controller controls the moving mechanism <NUM>.

Specifically, the fourth sensor <NUM> is disposed on the conveyance guide of the conveyance path between the winding roller <NUM> and the third conveyance roller pair <NUM>. As illustrated in <FIG> and <FIG>, the third conveyance roller pair <NUM> conveys the two-ply sheet PJ in reverse toward the position of the winding roller <NUM>, so that the gripped portion B of the two-ply sheet PJ becomes a front end in the reverse direction conveyance, and the fourth sensor <NUM> detects the front end of the two-ply sheet PJ conveyed in reverse, that is, the tip of one end of the gripped portion B. The controller uses a timing at which the fourth sensor <NUM> detects the tip of one end of the gripped portion B as a trigger to adjust and control a timing to stop the two-ply sheet PJ at the gripping position and a timing at which the gripper <NUM> grips the gripped portion B. Specifically, after a predetermined time has passed since the fourth sensor <NUM> detected the front end of the two-ply sheet PJ, the third conveyance roller pair <NUM> stops the reverse direction conveyance of the two-ply sheet PJ, and the cam <NUM> rotates to pivot the arm <NUM> of the moving mechanism <NUM> so that the gripper <NUM> moves from the releasing position illustrated in <FIG> to the gripping position illustrated in <FIG>.

The above-described control accurately performs an operation in which the end surface of the two-ply sheet PJ is sandwiched by the gripper <NUM> and the receiving portion 20b without abutting the end surface of the two-ply sheet PJ on any member.

As described above, the third conveyance roller pair <NUM> conveys the tip of one end of the gripped portion B of the two-ply sheet as a front end toward the winding start position W of the winding roller <NUM> in the third conveyance path K3 between the third conveyance roller pair <NUM> and the winding roller <NUM>.

With reference to <FIG>, <FIG>, <FIG>, and <FIG>, the separation claws <NUM> is described.

The separation claws <NUM> are claw-shaped members that are inserted into the gap C formed between two sheets P1 and P2 and between the winding roller <NUM> and the third conveyance roller pair <NUM> from both ends of the two-ply sheet PJ in the width direction of the two-ply sheet PJ in which the one end (that is the gripped portion B) is wound by the winding roller <NUM> and the other end (that is the bonding portion A) is nipped by the third conveyance roller pair <NUM>.

Specifically, in the present embodiment, the separation claws <NUM> are disposed at both sides of the conveyance path in the width direction that is the direction perpendicular to a plane on which <FIG> are illustrated and the horizontal direction in <FIG>. The separation claw <NUM> has a fin extending in the vertical direction and a plate. In a direction in which the separation claw <NUM> is inserted into the two-ply sheet PJ, the plate has a tip at the center in a width direction of the plate and a back-end. Each of a plate thickness and a plate width in the plate gradually increases from the tip to the back-end. A vertical length of the fin gradually increases from the tip of the fin in the direction in which the separation claw <NUM> is inserted into the two-ply sheet PJ. The back-ends of the fin and the plate in the separation claw <NUM> form a cross shape (see <FIG>). A pair of separation claws <NUM> is moved in the width direction of the two-ply sheet PJ by a driving device controlled by the controller so as not to contact each other.

A driving device to move the separation claws <NUM> in the width direction of the two-ply sheet PJ is described below. As illustrated in <FIG>, the sheet separation device <NUM> according to the present embodiment includes two separation claws 16a and 16b disposed to face each other. In <FIG>, a belt driving device causes the two separation claws 16a and 16b to approach or move away from each other. In <FIG>, a rack and pinion driving device causes the two separation claws 16a and 16b to approach or move away from each other.

Specifically, the belt driving device in <FIG> includes a driving pulley 300a, a driven pulley 300b, and a belt <NUM> stretched between the driving pulley 300a and the driven pulley 300b. The two separation claws 16a and 16b are attached to the belt <NUM> to face each other. One separation claw 16a is connected to the lower side of the belt <NUM>, and the other separation claw 16b is connected to the upper side of the belt <NUM>.

The belt driving device includes a drive transmission gear <NUM> attached to the driving pulley 300a. The drive transmission gear <NUM> receives the rotational driving force of the drive motor <NUM> via the motor output gear <NUM> and transmits the rotational driving force to the belt <NUM>.

In <FIG>, clockwise rotation of the drive motor <NUM> causes the separation claws 16a and 16b to approach each other, and counterclockwise rotation of the drive motor <NUM> causes the separation claws 16a and 16b to move away from each other.

The rack and pinion driving device in <FIG> includes a pinion <NUM> and two racks 420a and 420b extending in opposite directions and meshing with the pinion <NUM>. The two separation claws 16a and 16b facing each other are attached to the racks 420a and 420b, respectively. The pinion <NUM> is attached a drive transmission gear <NUM>. The drive transmission gear <NUM> receives the rotational driving force of the drive motor <NUM> via the motor output gear <NUM> and transmits the rotational driving force to the racks 420a and 420b.

The separation claws <NUM> configured as described above stand by at standby positions illustrated in <FIG> at which the separation claws <NUM> do not interfere with the conveyance of the sheet such as the two-ply sheet PJ in the third conveyance path K3 until the gap C is formed in the two-ply sheet PJ as illustrated in <FIG>. Subsequently, as illustrated in <FIG>, the separation claws <NUM> enter the gap C in the two-ply sheet PJ when the two-ply sheet PJ (configured by two sheets P1 and P2) is separated. As a result, the separation claws <NUM> secure the gap C to be large.

With reference to <FIG>, a position of the separation claw <NUM> in the present embodiment is described. The separation claw <NUM> is disposed on the side at which the winding roller <NUM> is disposed with respect to the imaginary plane S1 that includes the nip N of the third conveyance roller pair <NUM> and touches the winding roller <NUM> on the side at which the two-ply sheet PJ starts to be wound around the winding roller <NUM> that is the side indicated by the white arrow and not the side indicated by the black arrow in <FIG>. In other words, the separation claw <NUM> is disposed in a space that is bounded by the imaginary plane S1 and includes the winding roller <NUM>, and the imaginary plane passes through the nip of the third conveyance roller pair <NUM> and the winding start position W at which the two-ply sheet PJ starts to be wound around the winding roller.

When viewed from the rotation axis direction of the winding roller <NUM>, the winding start position W is a tangent point at which the winding roller <NUM> touches the imaginary plane S1. The imaginary plane S1 includes a tangent of the winding roller <NUM> at a predetermined position on the side at which the two-ply sheet PJ starts to be wound around the winding roller <NUM>. The imaginary plane S1 is a plane connecting the winding start position W and the nip N of the third conveyance roller pair <NUM> (more specifically, an end point of the nip N, which is the end point near the winding roller <NUM>). That is, the imaginary plane S1 represents the two-ply sheet PJ having one end wound around the winding roller <NUM> and the other end nipped by the third conveyance roller pair <NUM> and pulled by the winding roller <NUM> and the third conveyance roller pair <NUM>. The separation claw <NUM> is disposed on the side at which the winding roller <NUM> is disposed with respect to the imaginary plane S1 (the side indicated by the white arrow in <FIG>) above the third conveyance path K3.

More specifically, when viewed in a cross section orthogonal to the axial direction, the separation claw <NUM> is disposed above the imaginary plane S1 in <FIG>. In addition, the separation claw <NUM> is disposed between the two branched conveyance paths K4 and K5 and the third conveyance roller pair <NUM> (see <FIG>).

As described above, the separation claw <NUM> is arranged on the side at which the winding roller <NUM> is disposed with respect to the imaginary plane S1 that represents the sheet P2 of the two-ply sheet PJ in <FIG>. As a result, the separation claw <NUM> easily enters the gap C between the two sheets P1 and P2. The above-described configuration can prevent a disadvantage that the separation claw <NUM> is not inserted into the gap C between the two sheets P1 and P2 and cannot separate the two sheets P1 and P2. The above-described mechanism including the winding roller <NUM> winding the two-ply sheet and the separation claws <NUM> inserted into the two-ply sheet PJ to separate the two-ply sheet PJ can reduce the size of the sheet separation device as compared with a mechanism using a large-scale device such as a vacuum device to separate the two-ply sheet PJ. That is, without increasing the size of the sheet separation device <NUM>, the above-described mechanism can satisfactorily separate the two sheets P1 and P2 constituting the two-ply sheet PJ.

Additionally, with reference to <FIG>, the separation claw <NUM> is preferably disposed in a region sandwiched between two imaginary contact planes S <NUM> and S2 that are one imaginary contact plane S1 passing through the nip N of the third conveyance roller pair <NUM> and one tangent point of the outer peripheral surface of the winding roller <NUM> and the other imaginary contact plane S2 passing through the nip N of the third conveyance roller pair <NUM> and the other tangent point of the outer peripheral surface of the winding roller <NUM>. That is, since the outer peripheral surface of the upper roller in the third conveyance roller pair <NUM> limits bending the two-ply sheet PJ upward, the separation claw <NUM> is preferably disposed below the imaginary contact plane S2 and in a region sandwiched between the two imaginary contact planes S <NUM> and S2.

Alternatively, in <FIG>, in a sheet separation device having a sheet conveyance path including the second imaginary plane S2 and the winding roller <NUM> rotating clockwise to wind the two-ply sheet PJ around the winding roller <NUM>, the winding roller <NUM> rotates clockwise to wind the two-ply sheet PJ around the winding roller <NUM> from the winding start position Z of the winding roller <NUM>. In the sheet separation device described above, the separation claw <NUM> is disposed on the side at which the winding roller <NUM> is disposed with respect to the second imaginary contact plane S2 (that is the imaginary plane), that is, on the lower side from the second imaginary plane S2. That is, even when the winding roller <NUM> rotates in forward and in reverse, disposing the separation claw <NUM> in the region sandwiched between the two imaginary contact planes S1 and S2 (that are imaginary planes) to wind the two-ply sheet PJ around the winding roller <NUM> and separate the two-ply sheet PJ enables the separation claw <NUM> to satisfactorily separate the two sheets P1 and P2.

With reference to <FIG>, the switching claws <NUM> are described. The switching claws <NUM> are disposed between the separation claws <NUM> and the winding roller <NUM>. The two-ply sheet PJ is separated into the two sheets P1 and P2 by the separation claws <NUM>, and the two sheets P1 and P2 are given stiffness. The switching claws <NUM> separately guides the two sheets P1 and P2 to the two branched conveyance paths K4 and K5, respectively. The two branched conveyance paths K4 and K5 are branched from the third conveyance path K3 in different directions, and the third conveyance path K3 sandwiched by the two branched conveyance paths K4 and K5. The switching claws <NUM> are claw-shaped moving members and rotate in forward or in reverse within a range of a predetermined angle to guide the two-ply sheet PJ. Specifically, in the present embodiment, the switching claws <NUM> are a plurality of claws divided with a gap therebetween in the width direction that is the direction perpendicular to a plane on which <FIG> are illustrated. The switching claws <NUM> are configured to be rotatable about a support shaft. The controller controls a driving device that rotates the switching claws <NUM>.

The switching claws <NUM> configured as described above stand by at standby positions as illustrated in <FIG> at which the switching claws <NUM> do not interfere with the conveyance of the sheets such as the two-ply sheet PJ in the third conveyance path K3 before the switching claws <NUM> guide the sheets P1 and P2 with stiffness that are separated from the two-ply sheet PJ by the separation claws <NUM> to the branched conveyance paths K4 and K5. When the switching claws <NUM> guide the two sheets P1 and P2 separated from the two-ply sheet PJ by the separation claws <NUM> to the branched conveyance paths K4 and K5, respectively, the switching claws <NUM> rotate to positions at which the switching claws <NUM> prevent the two-ply sheet PJ from entering the third conveyance path K3 when viewed from the two-ply sheet PJ as illustrated in <FIG>. As a result, the first sheet P1 is guided to the first branched conveyance path K4, and the second sheet P2 is guided to the second branched conveyance path K5.

Specifically, as illustrated in <FIG>, the third conveyance roller pair <NUM> conveys the other end of the two-ply sheet PJ to the left side in <FIG> after the separation claws <NUM> are inserted into the gap C until the winding of the one end of the two-ply sheet PJ on the winding roller <NUM> is released. After the third conveyance roller pair <NUM> conveys the two-ply sheet PJ as illustrated in <FIG>, the third conveyance roller pair <NUM> conveys the one end of the two-ply sheet PJ to the right side as illustrated in <FIG> again, and the switching claws <NUM> guide the first sheet P1 separated by the separation claws <NUM> to the first branched conveyance path K4 and guide the second sheet P2 to the second branched conveyance path K5. Subsequently, as illustrated in <FIG>, the second conveyance roller pair <NUM> conveys the insertion sheet PM to the third conveyance path K3, that is, the right side in <FIG> to insert the insertion sheet PM between the two sheets P1 and P2 separated from the two-ply sheet PJ.

With reference to <FIG>, the first guide <NUM> is described below. The first guide <NUM> is disposed between the separation claws <NUM> (see <FIG>) and the winding roller <NUM> in the third conveyance path K3 and functions as the inner limiter to limit an amount of slack of the first sheet P1 that is an inner sheet of the two sheet P1 and P2 of the two-ply sheet PJ wound around the winding roller <NUM>.

Specifically, the first guide <NUM> as the inner limiter is the conveyance guide disposed on the side in which the winding roller <NUM> is disposed with respect to the imaginary plane S1 (see <FIG>), that is, the upper side indicated by a white arrow in <FIG>, in the third conveyance path. In other words, the first guide <NUM> as the inner limiter is disposed in the space bounded by the imaginary plane S1 and including the winding roller <NUM>. The first guide <NUM> has a curved surface that covers a part of the outer circumferential surface of the winding roller <NUM> and functions as the conveyance guide of the third conveyance path K3 and the conveyance guide of the first branched conveyance path K4 (see <FIG>). That is, the first guide <NUM> guides the sheet conveyed on the third conveyance path K3 and the sheet conveyed on the first branched conveyance path K4.

In the third conveyance path K3, the first guide <NUM> limits bending the two-ply sheet PJ upward (that is, bending the first sheet P1 upward. Note that the sheet P1 is nearer to the surface of the winding roller <NUM> than the second sheet P2) between the winding roller <NUM> and the third conveyance roller pair <NUM>. Therefore, the gap C in the two-ply sheet PJ that is mainly formed by bending the first sheet P1 upward is intensively formed between the first guide <NUM> and the third conveyance roller pair <NUM>. Accordingly, the separation claws <NUM> can enter the gap C to satisfactorily separate the two sheets P1 and P2constituting two-ply sheet PJ.

With reference to <FIG>, the second guide <NUM> is described below. The second guide <NUM> is disposed between the separation claws <NUM> (see <FIG>) and the winding roller <NUM> in the third conveyance path K3 and functions as the outer limiter to limit an amount of slack of the second sheet P2 that is an outer sheet of the two sheets P1 and P2 of the two-ply sheet PJ wound around the winding roller <NUM>. The slack of the second sheet P2 is caused by variation in rotations of the winding roller <NUM> and the third conveyance roller pair <NUM>.

Specifically, the second guide <NUM> as the outer limiter is the conveyance guide disposed on the side in which the winding roller <NUM> is not disposed with respect to the imaginary plane S1 (see <FIG>), that is, the lower side indicated by a black arrow in <FIG>, in the third conveyance path. In other words, the second guide <NUM> as the outer limiter is disposed in a space bounded by the imaginary plane S1 and not including the winding roller <NUM>. The second guide <NUM> is disposed to face the lower surface of the sheet from a portion upstream from the second conveyance roller pair <NUM> to an entrance of the second branched conveyance path K5 that is the fifth conveyance path in the forward direction (see <FIG>). That is, the second guide <NUM> guides the sheet conveyed on the third conveyance path K3.

In the third conveyance path K3, the two-ply sheet PJ may bend downward (in particular, the second sheet P2 may bend downward) between the winding roller <NUM> and the third conveyance roller pair <NUM>. The two-ply sheet PJ bends downward when the winding roller <NUM> winds the two-ply sheet PJ up counterclockwise and when a conveyance speed at which the winding roller <NUM> conveys the two-ply sheet PJ is slower than a conveyance speed at which the third conveyance roller pair <NUM> conveys the two-ply sheet PJ. Since the second guide <NUM> limits bending the two-ply sheet PJ downward when the two-ply sheet bends downward, the gap C in the two-ply sheet PJ that is mainly formed by bending the first sheet P1 upward is intensively formed in a region in which the winding roller <NUM> is disposed with respect to the imaginary plane S1 (see <FIG>), that is, an upper region indicated by the white arrow in <FIG>. Accordingly, the separation claws <NUM> can enter the gap C to satisfactorily separate the two sheets P1 and P2constituting two-ply sheet PJ.

With reference to <FIG>, the following describes operations of the sheet separation device <NUM> to separate the two-ply sheet PJ.

In the description of the operations, operations of the separation claws <NUM> is appropriately described with reference to <FIG>, and the control flow is described with reference to a flowchart of <FIG>, that is, <FIG> and <FIG>.

After the first feed roller <NUM> starts feeding the two-ply sheet PJ on the first feed tray <NUM> in step S1 of <FIG>, as illustrated in <FIG>, the second conveyance roller pair <NUM> conveys the two-ply sheet PJ with the bonding portion A as a front end in the forward direction that is a direction from the right side to the left side in <FIG> in the third conveyance path K3. At this time, the controller controls the moving mechanism <NUM> so that the gripper <NUM> is positioned at the gripping position inside the outer periphery of the winding roller <NUM>. That is, the cam <NUM> rotates to move to a position at which the cam <NUM> does not push the arm <NUM>. When the gripper <NUM> is positioned at the gripping position as described above, the gripper <NUM> does not interfere the sheet conveyance in the third conveyance path K3. In addition, the free end of the switching claws <NUM> rotate downward and stand by at the standby positions at which the switching claws <NUM> do not interfere with the conveyance of the sheets in the third conveyance path K3.

Subsequently, as illustrated in <FIG>, the third conveyance roller pair <NUM> conveys the two-ply sheet PJ in the forward direction until the gripped portion B of the two-ply sheet PJ (that is the one end of the two-ply sheet PJ and a back end of the two-ply sheet PJ conveyed in the forward direction) passes through the position of the winding roller <NUM>. After the two-ply sheet PJ is further conveyed in the forward direction, the third conveyance roller pair <NUM> stops the conveyance of the two-ply sheet PJ as illustrated in <FIG>. In order to determine the timing to stop the conveyance of the two-ply sheet PJ, the controller uses the timing at which the third sensor <NUM> detects the bonding portion A of the two-ply sheet PJ (that is a front end of the two-ply sheet PJ conveyed in the forward direction and the other end of the two-ply sheet PJ) as a trigger in step S2 of <FIG>. After the timing, that is, after the third sensor <NUM> detects the bonding portion A of the two-ply sheet PJ, the controller determines whether the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by a predetermined amount X1 in step S3 of <FIG> and stops the conveyance of the two-ply sheet PJ at the timing at which the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by a predetermined amount X1.

When the third conveyance roller pair <NUM> temporarily stops the conveyance of the two-ply sheet PJ, as illustrated in <FIG>, the gripper <NUM> moves from the gripping position to the releasing position in step S4 of <FIG>. That is, the cam <NUM> rotates to move to a position at which the cam <NUM> pushes the arm <NUM>. In this state, the gripped portion B of the two-ply sheet PJ can be received between the gripper <NUM> and the receiving portion 20b.

Then, as illustrated in <FIG>, the third conveyance roller pair <NUM> rotates in reverse to start conveyance of the two-ply sheet PJ in the reverse direction in step S5 of <FIG>. At this time, in order to convey the gripped portion B of the two-ply sheet PJ to the gripping position of the gripper <NUM> in the winding roller <NUM>, the fourth sensor <NUM> detects the gripped portion B of the two-ply sheet PJ that is the one end of the two-ply sheet PJ and the front end of the two-ply sheet PJ conveyed in the reverse direction.

Subsequently, as illustrated in <FIG>, the controller uses the timing at which the fourth sensor <NUM> detects the gripped portion B of the two-ply sheet PJ as a trigger in step S6 of <FIG> and stops the conveyance of the two-ply sheet PJ in step S7 of <FIG> at a timing at which the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by a predetermined amount X2 that is a timing at which the gripped portion B of the two-ply sheet PJ reaches a predetermined rotational position of the winding roller <NUM> that is the winding start position W. As illustrated in <FIG>, the gripper <NUM> is moved from the releasing position to the gripping position at the predetermined rotational position of the winding roller <NUM> in step S8 of <FIG>. That is, the cam <NUM> rotates to move to the position at which the cam does not push the arm <NUM>. In step S8, as illustrated in <FIG>, the end surface of the one end of the two-ply sheet PJ does not abut on any member, and the gripped portion B is gripped between the gripper <NUM> and the receiving portion 20b. The winding start position W in <FIG> is the position of the outer peripheral surface of the winding roller <NUM> at the predetermined rotational position. However, at the releasing position in <FIG> and the gripping position in <FIG>, the outer peripheral surface itself of the winding roller <NUM> does not exist. Therefore, the winding start position W is a position on an imaginary outer peripheral surface of the winding roller <NUM>.

Then, as illustrated in <FIG>, the winding roller <NUM> rotates in reverse (that is, counterclockwise) when the gripper <NUM> grips the two-ply sheet PJ, and, at the same time, the third conveyance roller pair <NUM> rotates in reverse again. As the winding roller <NUM> rotates, the gap C is formed between the two sheets P1 and P2 of the two-ply sheet PJ between the winding roller <NUM> and the third conveyance roller pair <NUM> as illustrated in <FIG>. While the gap C is formed, the first guide <NUM> and the second guide <NUM> limit the bend of the two-ply sheet PJ in the vicinity of the winding roller <NUM>. Accordingly, the gap C of the two-ply sheet PJ is intensively formed near the third conveyance roller pair <NUM>. The gap C is largely formed above the imaginary plane S1 (see <FIG>) described above.

As described above, the fourth sensor <NUM> detects the front end of the two-ply sheet PJ conveyed in reverse. The fourth sensor <NUM> is disposed between the third conveyance roller pair <NUM> and the winding roller <NUM> and downstream in the reverse direction from the third conveyance roller pair <NUM>. Since the controller uses the timing at which the fourth sensor <NUM> detects the gripped portion B of the two-ply sheet PJ conveyed in reverse as the trigger to determine the timing at which the gripper <NUM> and the receiving portion 20b grip the gripped portion B, the gripped portion B of the two-ply sheet PJ can be accurately conveyed to a desired gripping position regardless of variations in sheet lengths with respect to the sheet conveyance amount X2 (Note that the size of sheets includes an error even if the sheets are sold as the same size).

Disposing the fourth sensor <NUM> near the winding roller <NUM> between the third conveyance roller pair <NUM> and the winding roller <NUM> can shorten the sheet conveyance amount X2 regardless of the sheet length because the sheet conveyance amount X2 is measured since the fourth sensor <NUM> detects the front end of the two-ply sheet PJ conveyed in the reverse direction. The above-described configuration can reduce variation in the sheet conveyance amount X2 and enables an accurate conveyance of the gripped portion B of the two-ply sheet PJ to the desired gripping position. Accordingly, the fourth sensor <NUM> is preferably disposed near the winding roller <NUM>.

In step S9 of <FIG>, after the third conveyance roller pair <NUM> continues to rotate in reverse and the winding roller <NUM> starts the winding of the two-ply sheet PJ as illustrated in <FIG>, the third conveyance roller pair <NUM> stops the conveyance of the two-ply sheet PJ and the winding roller <NUM> stops the winding of the two-ply sheet PJ at the timing at which the third conveyance roller pair <NUM> conveys the two-ply sheet by a predetermined amount X3 as illustrated in <FIG>. In this state, the two-ply sheet PJ is wound around the winding roller <NUM> one or more times, and the gap C in the two-ply sheet PJ is sufficiently widened. In addition, the bonding portion A of the two-ply sheet PJ is sandwiched by the third conveyance roller pair <NUM>.

Next, as illustrated in <FIG>, the separation claws <NUM> are inserted into the gap C in the two-ply sheet PJ that is sufficiently widened in step S10 of <FIG>. That is, as illustrated in <FIG>, each of the pair of separation claws <NUM> is moved from the standby position in <FIG> to a position in <FIG> to separate the two-ply sheet PJ.

When the separation claws <NUM> move as described above, the pair of separation claws <NUM> can smoothly enter the gap C formed above the imaginary plane S1 described above because the pair of separation claws <NUM> are disposed to be movable in the width direction above the imaginary plane S1 (see <FIG>).

Next, as illustrated in <FIG>, the third conveyance roller pair <NUM> and the winding roller <NUM> start rotating in forward, that is, clockwise in step S11 of <FIG> after the separation claws <NUM> are inserted into the gap C. At this time, the bonding portion A may not be sandwiched by the third conveyance roller pair <NUM> when rotations of the winding roller <NUM> in forward (clockwise) can convey the two-ply sheet PJ. That is, the rotations of the winding roller <NUM> in forward may convey the bonding portion A of the two-ply sheet PJ to the third conveyance roller pair <NUM>, the bonding portion A may be sandwiched by the third conveyance roller pair <NUM>, and the third conveyance roller pair <NUM> may convey the two-ply sheet PJ.

In step S12 of <FIG>, as illustrated in <FIG>, the controller stops forward rotation in the third conveyance roller pair <NUM> and forward rotation in the winding roller <NUM> after the forward rotation in the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by a predetermined amount of X4. At this time, the two-ply sheet PJ is not wound around the gripper <NUM>, and the gripper <NUM> can release the gripping of the gripped portion B of the two-ply sheet PJ at the winding start position W. That is, at the winding start position W, the gripper <NUM> can move from the gripping position at which the gripper <NUM> grips the gripped portion B to the releasing position.

In this state, the gripper <NUM> moves from the gripping position to the releasing position so that the gripper <NUM> is in the third conveyance path K3 in step S13 of <FIG>. That is, the cam <NUM> rotates as illustrated in <FIG> to move to the position at which the cam <NUM> pushes the arm <NUM>. The gripper <NUM> releases gripping the two-ply sheet PJ. In the present embodiment, the cam <NUM> in the moving mechanism <NUM> moves to release the gripping of the gripper <NUM>, but the third conveyance roller pair <NUM> may pull the two-ply sheet from the gripper <NUM> to release the gripping and convey the two-ply sheet without the above-described movement of the cam <NUM> in the moving mechanism <NUM> when a pulling force due to the conveyance of the third conveyance roller pair <NUM> is larger than a force of the gripper <NUM> that grips the two-ply sheet PJ.

In step S14 of <FIG>, as illustrated in <FIG>, the third conveyance roller pair <NUM> again rotates in forward to start conveyance of the two-ply sheet PJ in the forward direction. At this time, the fourth sensor <NUM> detects the gripped portion B of the two-ply sheet PJ that is the one end of the two-ply sheet PJ and the back end of the two-ply sheet PJ conveyed in the forward direction to stop the gripped portion B near the separation claws <NUM>. In addition, the gripper <NUM> moves from the releasing position to the gripping position, and the switching claws <NUM> rotates clockwise from the standby position to a switching position after the gripped portion B of the two-ply sheet PJ that is the one end of the two-ply sheet PJ and the back end of the two-ply sheet PJ passes over the switching claws <NUM>. When the gripped portion B that is the back end of the two-ply sheet PJ conveyed in the forward direction reaches the vicinity of the separation claws <NUM> as illustrated in <FIG>, back ends of the two sheets P1 and P2 are largely separated and opened (see <FIG>).

The controller determines whether the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by a predetermined amount X5 after the timing, as a trigger, at which the fourth sensor <NUM> detects the back end of the two-ply sheet PJ conveyed in the forward direction in step S15 of <FIG> and stops the conveyance of the two-ply sheet PJ when the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by the predetermined amount X5. In step S16 of <FIG>, the third conveyance roller pair <NUM> rotates in reverse to start a conveyance of the two-ply sheet PJ in the reverse direction as illustrated in <FIG>. At this time, since the free ends of the switching claws <NUM> are disposed at the switching positions at which the switching claws <NUM> block the two-ply sheet PJ moving to the third conveyance path K3, the two sheets P1 and P2 separated each other are guided to the two branched conveyance paths K4 and K5, respectively, as illustrated in <FIG>. At this time, the fifth sensor <NUM> (see <FIG>) detects the bonding portion A of the two-ply sheet PJ that is the other end of the two-ply sheet PJ and the back end of the two-ply sheet PJ conveyed in the reverse direction to stop the conveyance of the two-ply sheet PJ so that the vicinity of the bonding portion A in the two-ply sheet PJ is nipped by the third conveyance roller pair <NUM>.

Subsequently, the controller uses, as a trigger, the timing at which the fifth sensor <NUM> (see <FIG>) detects the back end of the two-ply sheet PJ conveyed in the reverse direction that is the bonding portion A in step S17 of <FIG> and stops the conveyance of the two-ply sheet PJ at a timing at which the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by a predetermined amount X6 as illustrated in <FIG> in step S18 of <FIG>. When the third conveyance roller pair <NUM> conveys the two-ply sheet PJ by the predetermined amount X6, the bonding portion A of the two-ply sheet PJ is in the nip of the third conveyance roller pair <NUM> or at a position slightly leftward and downstream from the nip. That is, the third conveyance roller pair <NUM> nips the other end of the two-ply sheet PJ.

Subsequently, as illustrated in <FIG>, the controller starts feeding the insertion sheet PM from the second feed tray <NUM> (see <FIG>) in step S19 of <FIG>. At this time, the third sensor <NUM> detects the front end of the insertion sheet PM conveyed in the forward direction that is also referred to as the other end of the insertion sheet PM. In addition, as illustrated in <FIG>, the separation claw <NUM> moves to the standby position.

Subsequently, the controller uses the timing at which the third sensor <NUM> detects the front end of the insertion sheet PM as a trigger in step S20 of <FIG>. After the second conveyance roller pair <NUM> conveys the insertion sheet PM by a predetermined amount X7 since the third sensor <NUM> detects the front end of the insertion sheet PM, the third conveyance roller pair <NUM> again starts the conveyance of the two-ply sheet PJ in the forward direction in step S21 of <FIG> as illustrated in <FIG>. At this time, the insertion sheet PM is accurately sandwiched at a desired position between the two sheets P1 and P2.

Thus, the controller ends processes to insert the insertion sheet PM between the two sheets P1 and P2 in the two-ply sheet PJ. The third conveyance roller pair <NUM> conveys the two-ply sheet PJ with the insertion sheet PM inserted therein in the forward direction, and the two-ply sheet PJ with the insertion sheet PM inserted therein is placed on the ejection tray <NUM> (see <FIG>).

The sheet separation device <NUM> in the present embodiment forms the gap C between the two sheets P1 and P2 of the two-ply sheet PJ at the non-bonding portion near the bonding portion A in the state illustrated in <FIG> to separate (peel) the two sheets P1 and P2.

In contrast, the bonding portion A may be set as the gripped portion in the state illustrated in <FIG> if the third conveyance roller pair <NUM> nips the two-ply sheet PJ with sufficiently strong force. That is, in <FIG>, the bonding portion A of the two-ply sheet PJ is gripped by the gripper <NUM> and the receiving portion 20b, the two-ply sheet PJ is wound around the winding roller <NUM>, and the non-bonding portion is nipped and conveyed by the third conveyance roller pair <NUM>. At this time, the sheets P1 and P2 of the two-ply sheet PJ are conveyed in synchronization with each other without slipping by the rotation of the third conveyance roller pair <NUM>. For example, increasing the nip pressure of the third conveyance roller pair <NUM>, using roller material having a large coefficient of friction, or controlling the driving of the third conveyance roller pair <NUM> using various kinds of methods reduces slippage of the two sheets P1 and P2 to be less likely to occur, and the two sheets P1 and P2 can be separated (peeled) by forming a desired gap C in the two-ply sheet PJ. The above-described configuration can also reduce the number of times of conveyance of the two-ply sheet PJ until the insertion sheet PM is inserted into the two-ply sheet PJ.

Next, a first variation is described. As illustrated in <FIG>, a laminator <NUM> as the first variation includes the sheet separation device <NUM> illustrated in <FIG>.

The laminator <NUM> includes a lamination processor <NUM> downstream from the third conveyance roller pair <NUM> in the sheet separation device <NUM> in the forward direction. The lamination processor <NUM> performs a laminating process on the two-ply sheet PJ in which the insertion sheet PM is inserted between the two sheets P1 and P2 separated by the sheet separation device <NUM>.

The lamination processor <NUM> includes a plurality of heat and pressure roller pairs that apply heat and pressure to the two-ply sheet PJ while conveying, in the forward direction, the two-ply sheet PJ into which the insertion sheet PM is inserted. The two-ply sheet PJ into which the insertion sheet PM is inserted inside passes through the lamination processor <NUM>, and the entire region of the two-ply sheet PJ is joined. The two-ply sheet PJ subjected to the laminating process described above is ejected to the outside of the lamination processor <NUM> by an ejection roller pair <NUM> and is placed on the ejection tray <NUM>.

As described above, the laminator <NUM> according to the first variation performs a process to feed the sheets PJ and PM, a process to separate the two sheets P1 and P2 in the two-ply sheet PJ, a process to insert the insertion sheet PM into the space between the two separated sheets P1 and P2, and a process to perform the laminating process on the two-ply sheet PJ in which the insertion sheet PM is inserted, as a sequence of processes, thus enhancing the convenience for a user.

Since a part of the two-ply sheet PJ including a damaged front end surface is hard for the laminating process, the configuration of the present disclosure is useful.

Next, a second variation is described. As illustrated in <FIG>, an image forming apparatus <NUM> as the second variation includes the laminator <NUM> illustrated in <FIG> and an image forming apparatus main body that forms an image on a sheet P.

With reference to <FIG>, in the image forming apparatus <NUM>, multiple pairs of sheet conveying rollers disposed in the document feeder <NUM> feeds the original document D from a document loading table and conveys the original document D in a direction indicated by arrow in <FIG>, and the original document D passes over the document reading device <NUM>. The document reading device <NUM> optically reads image data of the original document D passing over the document reading device <NUM>.

The image data optically read by the document reading device <NUM> is converted into electric signals and transmitted to a writing device <NUM>. The writing device <NUM> emits laser beams onto the photoconductor drums 105Y, <NUM>, 105C, and <NUM> based on the electric signals of the image data in each of colors, respectively, performing an exposure process.

On the photoconductor drums 105Y, <NUM>, 105C, and <NUM> of the image forming units 104Y, <NUM>, 104C, and <NUM>, a charging process, the exposure process, and a developing process are performed to form desired images on the photoconductor drums 105Y, <NUM>, 105C, and <NUM>, respectively.

The images formed on the photoconductor drums 105Y, <NUM>, 105C, and <NUM> are transferred and superimposed onto the intermediate transfer belt <NUM> to form a color image. The color image formed on the intermediate transfer belt <NUM> is transferred to the surface of a sheet P (which is a sheet to be the insertion sheet PM) fed and conveyed by a feed roller <NUM> from a feeding device <NUM> at a position at which the intermediate transfer belt <NUM> faces the secondary transfer roller <NUM>.

After the color image is transferred onto the surface of the sheet P (that is the insertion sheet PM), the sheet P is conveyed to the position of a fixing device <NUM>. The fixing device <NUM> fixes the transferred color image on the sheet P.

Thereafter, the sheet P is ejected from the image forming apparatus main body of the image forming apparatus <NUM> by an ejection roller pair <NUM> and is fed into the laminator <NUM> as the insertion sheet PM. When the laminator <NUM> including the sheet separation device <NUM> receives the insertion sheet PM, the laminator <NUM> has completed the process described with reference to <FIG> (that is, the process to separate the two-ply sheet PJ) and performs the process described with reference to <FIG> (that is, the process to insert the insertion sheet PM into the two-ply sheet PJ) after the laminator <NUM> (the sheet separation device <NUM>) receives the insertion sheet PM. After the lamination processor <NUM> performs the laminating process on the two-ply sheet PJ into which the insertion sheet PM is inserted, the ejection roller pair <NUM> ejects the two-ply sheet PJ to the outside of the lamination processor <NUM> to place the two-ply sheet PJ on the ejection tray <NUM>.

As described above, a series of image formation processes (i.e. printing operations) in the image forming apparatus <NUM> and a series of sheet separation processes and the laminating process using the insertion sheet PM on which the image is formed are completed. In the second variation, the image forming apparatus <NUM> includes the laminator <NUM>, but may include the sheet separation device <NUM> illustrated in <FIG>.

The image forming apparatus <NUM> according to the second variation of the present disclosure is a color image forming apparatus but may be a monochrome image forming apparatus. The image forming apparatus <NUM> according to the second variation of the present disclosure employs electrophotography, but the present disclosure is not limited to this. The present disclosure may be applied to other types of image forming apparatuses such as an inkjet image forming apparatus and a stencil printing machine.

A third variation is described. As illustrated in <FIG>, an image forming system <NUM> according to the third variation includes the image forming apparatus <NUM> illustrated in <FIG> that forms the image on the sheet P and the laminator <NUM> illustrated in <FIG>, and the laminator <NUM> is detachably attached to the image forming apparatus <NUM>.

In the image forming system <NUM> illustrated in <FIG>, the image forming apparatus <NUM> performs the image formation described above with reference to <FIG> and ejects the sheet P (that is the insertion sheet formed a desired image) from the ejection roller pair <NUM> to the laminator <NUM>, and the laminator <NUM> performs the laminating process on the two-ply sheet PJ into which the insertion sheet PM has been inserted, and the ejection roller pair <NUM> ejects the two-ply sheet PJ to the outside of the laminator <NUM> to place the two-ply sheet PJ on the ejection tray <NUM>.

When the user does not select a laminating process mode as described above, the image forming apparatus <NUM> in the image forming system <NUM> ejects the sheet P formed the image by the image formation process from a second ejection roller pair <NUM> to the outside of the image forming apparatus <NUM> to place the sheet P on a second ejection tray <NUM>.

The laminator <NUM> is detachably attached to the image forming apparatus <NUM> and can be detached from the image forming apparatus <NUM> when the laminator <NUM> is not necessary. The image forming apparatus <NUM> from which the laminator <NUM> is detached uses a placement surface <NUM> to place the laminator <NUM> as an ejection tray to place the sheet P formed the image by the image formation process and ejected from the ejection roller pair <NUM> to the outside of the image forming apparatus <NUM>.

In the third variation, the image forming system <NUM> includes the detachable laminator <NUM>. However, the image forming system <NUM> may include the sheet separation device <NUM> illustrated in <FIG> detachable.

As described above, the sheet separation device <NUM> according to the present embodiment separates the non-bonding portion of the two-ply sheet PJ in which the two sheets P1 and P2 are overlapped and bonded at the bonding portion A and includes the winding roller <NUM> that rotates in a predetermined rotation direction to wind the two-ply sheet PJ, the third conveyance roller pair <NUM> to convey the two-ply sheet PJ toward the winding roller <NUM>, and the separation claws <NUM> inserted into the gap C formed between the two sheets P1 and P2 between the winding roller <NUM> and the third conveyance roller pair <NUM>. The separation claw <NUM> is disposed on the side at which the winding roller <NUM> is disposed with respect to the imaginary plane S1 that includes the nip N of the third conveyance roller pair <NUM> and touches the winding roller <NUM> on the side at which the two-ply sheet PJ starts to be wound around the winding roller <NUM>.

Thus, without increasing the size of the sheet separation device <NUM>, the above-described mechanism can satisfactorily separate the two sheets P1 and P2 constituting the superimposed sheet PJ.

The above-described embodiments are illustrative and do not limit this disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements at least one of features of different illustrative and exemplary embodiments herein may be combined with each other at least one of substituted for each other within the scope of this disclosure and appended claims. The number, position, and shape of the components described above are not limited to those embodiments described above. Desirable number, position, and shape can be determined to perform the present disclosure.

Claim 1:
A sheet separation (<NUM>) device configured to separate a non-bonding portion of a two-ply sheet (PJ) in which two sheets (P1, P2) are overlapped and bonded together at a bonding portion (A) of the two-ply sheet, the sheet separation device comprising:
a winding roller (<NUM>) configured to rotate and wind the two-ply sheet (PJ), the winding roller (<NUM>) comprising a receiving portion (20b);
a conveyance roller pair (<NUM>) configured to convey the two-ply sheet (PJ) toward the winding roller (<NUM>);
a separation claw (<NUM>) configured to be inserted into a gap (C) between the two sheets (P1, P2) at a position between the winding roller (<NUM>) and the conveyance roller pair (<NUM>), the separation claw (<NUM>) being disposed in a space that is bounded by an imaginary plane (S <NUM>) and includes the winding roller (<NUM>), the imaginary plane passing through a nip (N) of the conveyance roller pair (<NUM>) and a winding start position (W) at which the two-ply sheet (PJ) starts to be wound around the winding roller (<NUM>); and characterized in that it comprises
a gripper (<NUM>) configured to grip one end of the two-ply sheet (PJ), that is opposite an end at which the bonding portion (A) is formed, with the receiving portion (20b) at the winding start position (W).