KR200361547Y1 - Apparatus for automatically turning a page of a booklet - Google Patents

Abstract

A page switching device for turning over a booklet is disclosed. The page switching device includes a book conveying member including a conveying path and a conveying driving device for guiding a booklet, a switching part including a switching roller for turning a booklet of the conveyed booklet, a page shutter and a page shutter disposed adjacent to the switching roller. And a shutter member including a support that moves up and down, and a curved member that partially curves the booklet in association with the shutter member in some of the vertical movement sections of the shutter member. The number of electronic components can be reduced because the curved member can be operated by using the movement of the shutter member, and the height protruding by the curved member can be adjusted according to the thickness of the booklet, making it easier to turn over the booklet. have.

Description

Page turning device of booklet {APPARATUS FOR AUTOMATICALLY TURNING A PAGE OF A BOOKLET}

The present invention relates to a page switching device for turning a booklet, and more particularly, to a page switching device for automatically switching a book or other booklet (Leaf or Page).

As the functions of the banks are diversified, the bank's business is not only performed within the bank, but various transactions are carried out through various routes. Banks use bankbook organizers to fill out these transactions, and bank employees and customers can conveniently print the financial transactions of towels.

If there is no more blank space to print on the first inserted bankbook page, or if the already inserted bankbook page has been printed but the remaining transaction details remain, the conventional bankbook organizer displays the next page to the user through the screen or voice. The user passes through the bankbook by requesting it to be inserted, and the user uses the method of manually turning over the page of the discharged bankbook.

However, as the frequency of cash withdrawal, bank account deposit, telebanking, and internet banking, etc., increased through the automated teller machine, the transactions recorded in the bank account increased significantly, and the number of visits to the bank by customers was reduced. For example, there have been cases where the details to be filled in the account book organizer continue to accumulate.

In general, since the transaction history written on one side of the account is about 22 to 25 lines, there is a shortage of space while printing the transaction history, and the user frequently needs to turn over the page. This can be inconvenient for the customer. In particular, if the account can not be re-injected despite the remaining transaction details of the remaining to be printed, there is a problem that there is a difficulty in post-processing after the failure. Therefore, methods for solving these problems have been continuously presented.

In recent years, a bankbook arranging device which automatically turns a page of a bankbook without discharging the bankbook by additionally attaching a page switching device capable of automatically turning a page into a bankbook printer has been disclosed. In addition, such a page switching device is attached to an ATM, including a bank account arranging function, thereby assisting the user to conveniently organize the account.

It is necessary to transfer the passbook to the correct position for the page switching operation, there is a possibility that problems such as page folding, page jam (jam), page breakage, etc. may occur. On the other hand, the page turning of the passbook transferred to the right position is due to the page change roller, the contact pressure applied to the page by the page change roller, the rotation speed of the page change roller, the material and shape of the change roller, the material and shape of the page, etc. Problems such as page switching or multiple pages being switched together may occur due to various factors.

In general, in order to facilitate page turning of the passbook, an apparatus for partially curved the passbook is used. This bending device ensures contact between the transfer roller and the passbook by extending the contact between the transfer roller and the passbook by partially bending the contact area of the transfer roller before the changeover roller rotates, so as to extend the section that is in contact with each other and to easily separate one piece from the passbook. You can do it.

1A and 1B are configuration diagrams of a conventional page switching apparatus for explaining a conventional bending apparatus, and FIG. 2 is a bottom perspective view of the bending apparatus of FIG.

1A, 1B and 2, the conventional page switching apparatus 10 includes a book transfer member 120, a first switching unit 150, a second switching unit 160, a shutter member 70, and the like. The curved member 80 is included. More specifically, the page switching device 10 is used to pass through a bankbook, and is used in a bankbook printer such as a cash register or a cash dispenser, which also functions as a bankbook organizer.

The booklet conveying member 120 includes a conveying path 130 and a conveying drive device 140, the conveying path 130 guides the unfolded bankbook, and the conveying drive device 140 drives the rollers 142a and 142b. The passbook can be conveyed in the front-rear direction by using the support rollers 144a and 144b. The transport path 130 is provided by the first upper plate 134 and the second upper plate 136 located on the lower plate 132 and the lower plate 132, and the first and second upper plates 134, 136 is spaced apart from the lower plate 132 by a predetermined interval.

The first switching unit 150 is mounted adjacent to the first support roller 144a to cooperate with the book conveying member 120 to turn over the paper pieces of the passbook in the forward direction. The first switch unit 150 includes a first switch roller 152, a first guide inclined surface 154, a first number detecting groove 156, and a first number detecting sensor 158. As the first switching roller 152 rotates, it is possible to push up the pieces of the passbook, and the pushed-up pieces are separated from the passbook and positioned on the first guide inclined surface 154.

The second switching unit 160 is mounted adjacent to the second support roller 144b, so as to cooperate with the book transfer member 120 to flip the bank pieces in the reverse direction. The second switching unit 160 also includes a second switching roller 162, a second guide inclined surface 164, a second number detecting groove 166, and a second number detecting sensor 168. As the second switching roller 162 rotates, it is possible to push up the fulcrum of the passbook in the reverse direction, and the dilated lip is separated from the fulcrum and positioned on the second guide inclined surface 164.

The shutter member 70 is mounted between the first upper plate 134 and the second upper plate 136. The shutter member 70 is engaged with the page shutter 72 located above, the rack 78 for vertically transferring the page shutter 72, and the rack 78, and the driving pinion for conveying the shutter member 70 vertically. 74 and driven pinion 76. The drive pinion 74 receives a driving force from the motor, and can engage the driven pinion 76 to move the rack 78 up and down.

When transferring the bankbook, the page shutter 72 is in the lowered position to cover between the first and second top plates 134, 136. Since the page shutter 72 covers the open upper part of the conveying path 130, the passbook can move inside the conveying path 130 without being separated. The page shutter 72 eliminates empty spaces between the upper plates 134 and 136 of the passbook, thereby guiding the unfolded passbook to prevent page folding, page jams, and page breakage. However, after transferring the passbook to the desired position, the page shutter 72 moves to the lifted position with the rack 78 ascending, and the upper portion of the conveyance path 130 is moved by the upward movement of the page shutter 72. Partially open. When the page is switched by the first or second switching units 150 and 160 by opening the upper portion of the transfer path 130, the turned pieces may be located on the guide slope without being disturbed by the page shutter 72. have.

At the same time as the page shutter 72 ascends or ascends, the curved member 80 also starts to operate so that a portion of the curved finger 88 protrudes from the lower plate 132, and the curved curved finger 88 protrudes. The account is partially curved. Since the part contacting the changeover roller is convex, the friction force between the first changeover roller 152 and the passbook can be increased, the pushed-up path can be longer, and the passbook has a restoring force as a whole. It is also very easy to separate.

The curved member 80 is to bend the passbook when the page is switched, and is installed below the page shutter 72 and the bottom surface of the lower plate 132. The curved member 80 is connected to the solenoid 82, the link 84 connected to the solenoid 82, the curved bracket 86 connected to the end of the link 86, and the curved finger 88 of the curved bracket 86. It includes. After the page shutter 72 is raised, the solenoid 82 is operated to pull the link 84, and the link 84 is moved to rotate the curved bracket 86. As the curved bracket 86 rotates, the curved finger 88 also rotates together, and the curved finger 88 protrudes into the transport path 130 through a hole formed in the lower plate 132.

Then, the first switch roller 152 rotates to separate one piece from the booklet, and the book transfer member 120 moves the opposite direction to complete the page change.

The conventional page switching apparatus 10 includes a drive motor for driving the shutter member 70 and a solenoid 82 for operating the curved member 80. Since the drive motor and the solenoid 82 must be controlled so as to be harmonized with each other as separate electronic components, there is a possibility of malfunction.

In addition, the solenoid 82 has a characteristic that the projecting height of the curved finger 88 is always constant because the link 84 merely moves a certain stroke. However, according to the paper material of the passbook, the characteristics of being separated or not separated from other papers may be determined, and there may be cases in which a large or small curve is required depending on the thickness of the passbook to be curved. It has the disadvantage of not being adjustable.

The present invention is to solve the above-mentioned problems, an object of the present invention is to provide a page switching device that can operate the shutter member and the curved member from one power source.

Another object of the present invention is to provide a page switching apparatus whose structure can adjust the height at which the curved finger protrudes from the curved member.

Another object of the present invention is to ensure the operation of the switching device without malfunction by reducing the number of electronic components used, the page height of the curved finger can adjust the height of the curved finger according to the material of the booklet and the thickness of the booklet It is to provide a switching device.

1A and 1B are configuration diagrams of a conventional page switching device for explaining a conventional bending device.

FIG. 2 is a bottom perspective view of the bending device of FIG. 1. FIG.

3 is a perspective view of a page switching apparatus according to an embodiment of the present invention.

4 is a right side view for explaining the internal structure of the page switching apparatus according to the present embodiment.

5 is a perspective view schematically illustrating the shutter member and the curved member according to the present embodiment.

6 is a bottom perspective view of the page switching device for explaining when the shutter member is in the lowered position according to the present embodiment.

FIG. 7 is a side view illustrating the shutter member and the curved member in the page switching apparatus of FIG. 6.

8 is a bottom perspective view of the page switching device for explaining when the shutter member is in the raised position according to the present embodiment.

FIG. 9 is a side view illustrating the shutter member and the curved member in the page switching apparatus of FIG. 7.

10 is a configuration diagram for explaining the shutter member and the curved member according to the present embodiment.

<Explanation of symbols for the main parts of the drawings>

100: page switching device 112: first bracket

114: second bracket 120: booklet conveying member

130: transfer path 140: transfer drive device

142a, 142b: Drive roller 144a, 144b: Support roller

150: 1st switch part 152: 1st switch roller

153: First roller rotating shaft 154: First guide slope

156: The first number detecting groove 158: The first number detecting sensor

160: 2nd switching part 162: 2nd switching roller

163: 2nd roller rotating shaft 164: 2nd guide inclined surface

166: second shot detection groove 168: second shot detection sensor

170: Shutter member 172: Page shutter

178: Rack 179: Support shaft

180: curved member 182: curved bracket

186: curved finger 210: drive unit

220: Roller change department

According to a preferred embodiment of the present invention for achieving the above object of the present invention, the page switching device includes a book transfer member, the switching unit, the shutter member and the curved member.

The booklet conveying member includes a conveying path and a conveying driving device to convey the booklet in the forward and backward directions on the conveying path, and the switching unit functions to turn over the booklet conveyed by the booklet conveying member. The switching unit may be designed to turn over the paper piece in one direction or two directions according to the intention of the designer, and includes a turning roller for turning the paper piece using frictional force.

The shutter member includes a page shutter, a rack, a drive pinion, a driven pinion, and a shutter motor, the rotational force of the shutter motor is transmitted to the drive pinion and the driven pinion, and with respect to the rotation of the pinion, the rack moves up and down relatively to rotate the page shutter. Transfer it up and down. Also, a lower end of the rack is equipped with a support for lifting the curved member.

The curved member includes a curved bracket and a curved finger formed on the curved bracket. As the shutter member is raised, the support is supported to lift the curved bracket, and the curved finger formed integrally with the curved bracket protrudes into the conveying path to bend the booklet. The curved bracket is then supported by the support in some sections where the shutter member approaches the highest peak.

Unlike the conventional curved member, the curved member of the present invention does not include a separate driving component such as a solenoid, and only protrudes the curved finger using the vertical movement of the shutter member. Therefore, the page switching apparatus can perform the shutter function and the curved function simultaneously only by including the shutter motor for driving the shutter member.

In addition, the shutter motor can adjust the vertical movement distance of the shutter member, as compared with the solenoid which can not adjust the movable length, by using this can also adjust the height of the protruding fingers.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments.

3 is a perspective view of a page switching apparatus according to an embodiment of the present invention, Figure 4 is a right side view for explaining the internal structure of the page switching apparatus according to the present embodiment, Figure 5 is a shutter member according to the present embodiment And a perspective view schematically illustrating the curved member.

3 to 5, the page switching apparatus 100 according to the present embodiment may include a book transfer member 120, a first switching unit 150, a second switching unit 160, a shutter member 170, The curved member 180, the driving unit 210, and the roller changing unit 220 are included. More specifically, the page switching device 100 is used for handing over a bankbook, and is used in a bankbook printer such as a cash dispenser or a bankbook function.

Booklet conveying member 120 includes a conveying path 130 and the conveying drive device (140). The transfer path 130 is for guiding the opened booklet and is located adjacent to the transfer path of the bankbook printer (not shown). The transport path 130 is provided by the first upper plate 134 and the second upper plate 136 positioned on the lower plate 132 and the lower plate 132. The first and second top plates 134, 136 are spaced apart from the bottom plate 132 by a predetermined distance and guide the unfolded booklet to move along the intended path.

In addition, the transfer drive device 140 is for transferring the passbook, and includes a first drive roller 142a and a second drive roller 142b which are installed below the transfer path 130, and the first drive roller ( And a first support roller 144a and a second support roller 144b installed above the transfer path 130 in correspondence with each of the 142a and the second driving roller 142b. Several drive rollers 142a and 142b and support rollers 144a and 144b are disposed up and down and partially exposed to the inside of the transfer path 130 to be in contact with the upper and lower surfaces of the passbook. The first and second support rollers 144a and 144b are supported by the first and second drive rollers 142a and 142b to support the back surface of the passbook, and the first and second drive rollers 142a and 142b are rotated. Accordingly, the passbook is pressurized and transferred at a constant pressure. In this embodiment, since the driving rollers 142a and 142b and the support rollers 144a and 144b are connected to each other by the gear 148, the driving rollers can be transferred while rotating together, and the transfer motor is driven through the gears. Driving force may be provided to the 142a and 142b and the support rollers 144a and 144b. In addition, the first support roller 144a and the second support roller 144b may be in close contact with a passbook in which a pressure plate spring installed upward of the rotation shaft presses the rotation shaft downward.

The first upper plate 134 and the second upper plate 136 are each equipped with a position detection unit 138 for detecting the position of the passbook. The position detection unit 138 can detect whether or not the pass of the passbook, the position detection unit 138 to the outside of the support rollers (144a, 144b) and the driving rollers (142a, 142b), respectively. At least one or more may be installed to determine whether the passbook is transferred to a desired position during forward or reverse transfer of the passbook. In addition, the booklet conveying member 120 can transfer the passbook in the front-back direction to an optimal position that can pass the handbook of the passbook.

In addition, the booklet thickness sensor 139 is mounted adjacent to the position detecting unit 138. The thickness sensor 139 may detect the thickness of the booklet passing through the transfer path 130.

The first switching unit 150 is mounted adjacent to the first support roller 144a to cooperate with the book conveying member 120 to turn over the paper pieces of the passbook in the forward direction. The first switch unit 150 includes a first switch roller 152, a first guide inclined surface 154, a first number detecting groove 156, and a first number detecting sensor 158. The first switching roller 152 is mounted to the first roller rotation shaft 153, has a protruding shape and is made of a rubber material.

Accordingly, the first switching roller 152 may push up the pieces of the passbook while rotating, and the pushed-up pieces are separated from the passbook and positioned on the first guide inclined surface 154. The first guide inclined surface 154 is disposed on the upper portion of the first switching roller 152 and guides the piece that is converted in the forward direction. In addition, a first number sensing groove 156 is formed at an upper end of the first guide inclined surface 154 to partially insert the end of the switched paper, and the number of switched paper is detected in the first number sensing groove 156. The first number detecting sensor 158 is mounted.

The second switching unit 160 is mounted adjacent to the second support roller 144b, so as to cooperate with the book transfer member 120 to flip the bank pieces in the reverse direction. The second switching unit 160 also includes a second switching roller 162, a second guide inclined surface 164, a second number detecting groove 166, and a second number detecting sensor 168. The second switching roller 162 is mounted on the second roller rotation shaft 163, has a protruding shape, and is made of a rubber material so as to face the first switching roller 152. As the second switching roller 162 rotates, it is possible to push up the fulcrum of the passbook in the reverse direction, and the dilated lip is separated from the fulcrum and positioned on the second guide inclined surface 164. The second guide inclined surface 164 is disposed on the upper portion of the second switching roller 162 and guides the piece that is converted in the forward direction. In addition, a second number sensing groove 166 is formed at an upper end of the second guide inclined surface 164 to partially insert the end of the switched piece, and the number of switched pieces is detected in the second number detecting groove 166. The second number detecting sensor 168 is mounted.

The shutter member 170 is mounted between the first upper plate 134 and the second upper plate 136. The shutter member 170 is engaged with the page shutter 172 located above, the rack 178 for vertically transferring the page shutter 172, and the rack 178, and the driving pinion for conveying the shutter member 170 up and down. 174 and driven pinion 176, and shutter motor 171 for operating the shutter member 170. The drive pinion 174 receives a driving force from the shutter motor 171, and may engage the driven pinion 176 to move the rack 178 up and down. At the lower end of the rack 178, a support shaft 179 connecting both sides is mounted.

When transferring the passbook, the page shutter 172 is in the lowered position to cover between the first and second top plates 134, 136. Since the page shutter 172 covers the open upper part of the conveying path 130, the passbook can move inside the conveying path 130 without being separated. The page shutter 172 eliminates empty spaces between the upper plates 134 and 136 of the passbook, thereby guiding the unfolded passbook to prevent page folding, page jams, and page breakage.

The curved member 180 is to bend the passbook when switching pages, and is installed below the page shutter 172. The curved member 180 includes a curved bracket 182 and a curved finger 186. The curved bracket 182 is formed on both sides of the rotation shaft 183, and each curved bracket 182 is integrally formed with a curved finger 186 facing upward. A support surface 184 is formed at a lower end of the curved bracket 182, and the support surface 184 is formed corresponding to the support shaft 179.

Hereinafter, the operation between the shutter member 170 and the curved member 180 will be described.

FIG. 6 is a bottom perspective view of the page switching apparatus for explaining when the shutter member is in the lowered position, and FIG. 7 is a side view illustrating the shutter member and the curved member in the page switching apparatus of FIG. 6.

6 and 7, after transferring the passbook to the desired position, the shutter member 170 is stopped in the lowered position, the curved bracket 182 and the curved finger 186 is the lower plate ( 132) located below. The shutter shaft 188 is formed in the transverse direction adjacent to the curved bracket 182 and the curved finger 186, and the curved bracket 182 and the curved finger 186, which are lowered by their own weight, are attached to the shutter shaft 188. It is supported and fixed.

FIG. 8 is a bottom perspective view of the page switching apparatus for explaining when the shutter member is in an elevated position, and FIG. 9 is a side view for explaining the shutter member and the curved member in the page switching apparatus of FIG.

Referring to FIGS. 8 and 9, after the booklet is moved to the correct position, the driving pinion 174 and the driven pinion 176 are rotated by the shutter motor 171, and the page shutter 172 is the rack 178. ) Is moved to the rising position with the rise of the upper part, and the upper part of the transfer path 130 is partially opened by the rising movement of the page shutter 172.

When the page is switched by the first or second switching units 150 and 160 by opening the upper portion of the transfer path 130, the turned pieces may be located on the guide slope without being disturbed by the page shutter 172. have. In addition, intermediate guides 155 and 165 for switching are provided between the guide inclined surfaces 154 and 164 to facilitate page switching.

As the shutter member 170 approaches the highest apex position, the support shaft 179 comes into contact with the support surface 184 of the curved bracket 182, and the support shaft 179 supports the curved bracket 182. As it rises, the curved finger 186 is lifted up. As a result, the end of the curved finger 186 is exposed to the upper portion of the lower plate 132, it is possible to convexly curving the passbook located on the transfer path 130.

Hereinafter, with reference to the drawings will be described a process of switching the bank pieces of the passbook in the forward direction.

The curved finger 186 protrudes and convexly curses the bankbook, and then the first switching roller 152 pushes up the banknote of the bankbook while making one rotation. The pushed-up piece is separated from the bankbook and enters between the first and second top plates 134 and 136 and is positioned on the first guide inclined surface 154. At this time, since the page shutter 172 is in the ascending position, the pushed up piece may easily enter between the first and second upper plates 134 and 136 without being disturbed by the page shutter 172.

After the switched pieces are positioned on the first guide inclined surface 154, the book conveying member 120 conveys the passbook in the direction in which the first driving roller 142a and the first supporting roller 144a are located. As the bankbook is transferred, the changed pieces are raised along the first guide inclined surface 154, and the ends of the converted pieces are inserted into the first number detecting groove 156. At this time, the first number detecting sensor 158 measures the number of sheets inserted in the first number detecting groove 156.

Then, the book conveying member 120 is to further pass the passbook, the converted piece is relatively moved in the forward direction. As the central portion of the passbook enters between the first upper plate 134 and the lower plate 132, the switched pieces are also brought into close contact with the passbook in a turned over state, and as a result, the pieces pass completely in the forward direction.

If two or more pieces of paper are detected by the first number detecting sensor 158, the page switching apparatus 100 may switch the pieces of paper in the reverse direction. At this time, the second switching unit 160 is used instead of the first switching unit 150, the second switching unit 160 is used to switch the paper in the reverse direction, and the second sheet detecting sensor 168 of the paper You can verify the number of copies. By repeating this process, the above operation is repeated until the desired number of pages is correctly converted.

10 is a configuration diagram for explaining the shutter member and the curved member according to the present embodiment.

Referring to FIG. 10, the support shaft 179 of the shutter member 170 starts to rise from the lowered position START to support the support surface 184 of the curved bracket 182, and continues to rise to the curved finger. You can move until 186 is exposed. Since the shutter member 170 moves up and down by the shutter motor 171, the shutter member 170 has an advantage of being able to variously adjust the height of the support shaft 179.

As shown, the support shaft 179 may move to the first raised position up1 and may move to the second raised position up2. By using this it is possible to adjust the height (d1, d2) that the curved finger 186 is exposed, it is to adjust the degree of bending according to the thickness of the passbook paper material or passbook.

Therefore, in the case of a thick passbook, the page turning can be more reliably increased by increasing the exposed portion of the curved finger 186. In the case of a thin passbook, the exposed portion can be reduced to find the degree of bending suitable for the page turning. For example, the exposed height of the curved finger 186 may be variously adjusted, such as 2.0 mm, 2.5 mm, 3.0 mm.

The page switching apparatus according to the present invention can operate both the shutter member and the curved member by using one shutter motor. In addition, by using a servo motor or step motor instead of a solenoid, the stop height of the shutter member can be adjusted in various ways. By using this property, the height of the protruding curved finger can be changed according to the paper material of the booklet or the thickness of the booklet. have.

In addition, by reducing the number of electronic components used, manufacturing costs, etc. can be lowered, and the number of parts to be controlled is reduced, thereby simplifying control and reducing the possibility of malfunction.

As described above, the present invention has been described with reference to a preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

Claims (6)

In a page switching device for turning over a booklet, A book conveying member including a conveying path and a conveying driving device for guiding the booklet; A switching unit disposed on the transfer path and including a switching roller for turning over a booklet; A page shutter disposed adjacent to the changeover roller and a support tool for moving up and down together with the page shutter, wherein the page shutter guides the transfer of the booklet in a descending position when the booklet is transported, A shutter member that provides a space for the switched paper to pass in the raised position when the paper is switched; And A curved bracket moving along a predetermined path and a curved finger interlocked with the curved bracket, wherein the curved bracket is supported and moved by the supporter in some of the vertical movement sections of the shutter member, The curved finger temporarily protruding into the conveying path in response to the movement to partially curve the booklet; The method of claim 1, In the booklet conveying member, the conveying drive device includes a drive roller partially exposed toward the inside of the conveying path and a support roller disposed opposite to the drive roller to support the rear surface of the booklet. Device. The method of claim 1, The shutter member further includes a rack for transporting the page shutter up and down, a drive pinion and a driven pinion for engaging the rack and transporting the page shutter up and down, the support being connected to the lower end of the rack, A page switching device positioned below the curved bracket, wherein the support supports the lower portion of the curved bracket when the shutter member approaches the highest vertex. The method of claim 1, The switching unit includes a guide inclined surface which is disposed on the upper portion of the switching roller to guide the switched pieces, the upper end of the guide inclined surface is formed with a number sensing groove is inserted into the end portion of the switched pieces, the number of detection The groove switching apparatus, characterized in that it comprises a number of sensors for detecting the number of the switched pieces of paper. The method of claim 1, And the thickness detecting sensor is mounted on the conveying path to detect the thickness of the booklet. The method of claim 1, A shutter shaft is mounted adjacent to the curved bracket and the curved finger, and limits the rotation range of the curved bracket and the curved finger that fall by the weight or rise by the shutter member by using the shutter shaft. Page switcher.