JP2954860B2 - Media transport device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided drive type medium transport device in which a pair of drive rollers for holding a recording medium is driven by a drive unit.

[0002]

2. Description of the Related Art A recording medium capable of recording / reproducing a magnetic signal, for example, a medium transport apparatus which transports a magnetic card and records / reproduces the magnetic signal to / from the card by an information recording / reproducing head such as a magnetic head, has already been known. It is used in various fields. As such a medium transport device, there is a double-side drive system for driving both drive roller pairs for the purpose of increasing the card transport force. In this double-sided drive type media transport device,
The opposing drive rollers are driven by drive means, respectively.
The magnetic card inserted into the medium transport path is transported while being held between both rollers.

[0003]

A problem with the above-described double-sided drive type medium transport apparatus is that a problem due to a difference in peripheral speed between the pair of drive rollers facing each other is likely to occur. For example, even when the drive roller is formed to have the same diameter and is driven at the same rotation speed, the peripheral speed of the drive roller, that is, the roller surface speed or the medium transport speed at the outer diameter including the deformation of the roller itself, is the driving force. In practice, it is difficult to make the peripheral speed the same due to the loss of the transmission system, the difference in the roller diameter due to the degree of wear of the rollers and the individual differences in the roller manufacturing, and it is unclear which roller is faster or slower. In the transport of the card by the drive roller pair in such a state, it is difficult to stably run the card without knowing which drive roller is used to transport the card. Recording / playback is impossible. SUMMARY OF THE INVENTION It is an object of the present invention to provide a medium conveyance device that can stably convey a recording medium.

[0004]

Therefore, according to the first aspect of the present invention, a main driving roller driven integrally with the driving means by the driving means and an elastic belt interposed between the driving means and the main driving roller. And at least one pair of drive rollers for nipping and transporting the recording medium. According to a second aspect of the present invention, there is provided a pressing and moving means for enabling the sub-drive roller to move with respect to the main drive roller and applying a pressing force to the recording medium by the movement of the sub-drive roller. According to the third aspect of the invention, the diameters of the main drive roller and the sub drive roller are set to be substantially the same, and the same deformation amount is provided when the same pressing force is applied.

[0005]

An embodiment of the present invention will be described below with reference to the drawings. The medium conveyance device indicated by reference numeral 1 in FIG.
It is nipped and conveyed by the driving roller pair 6, the second driving roller pair 7, and the third driving roller pair 8, and is converted into magnetic information by magnetic heads 4 and 5 as information recording / reproducing heads arranged facing the medium conveying path 2. The recording / reproducing signal is transmitted and received.

As shown in FIG. 2, the medium transport path 2 is formed between frames 1A and 1B which are arranged in parallel to face each other. At the insertion port 2 a of the medium transport path 2, card detecting means 9 and 10 are arranged to face each other via the medium transport path 2. The card detecting means 9 and 10 detect whether or not the magnetic card C is a magnetic card based on the presence or absence of a magnetic signal of the inserted magnetic card C. In this case, activation of the drive motor 11 serving as a drive source of the drive means and medium This is one of triggers for opening and closing a well-known shutter mechanism (not shown) that can move in and out of the transport path 2.

The first, second and third drive roller pairs 6,
1 and 2, main driving rollers 6A, 7A and 8A arranged below the medium conveying path 2 and sub driving rollers 6B arranged above the medium conveying path 2 as shown in FIGS. 7B,
8B. Main drive roller 6
A, 7A, 8A and sub-drive rollers 6B, 7B, 8B
It is a rubber roller having a rubber layer on its outer periphery, and is a double-sided drive system that is individually driven by drive means described later.

The main drive rollers 6A, 7A, 8A are provided with a pair of bearings 18a, 18b,
The drive shafts 12, 13, and 14 are fixed via the respective drive shafts 18 c. The drive shafts 12, 13, 14 have
Belt pulley 19 constituting drive means 19 on the main drive side
1, 192 and 193 are provided. Belt pulley 1
Reference numerals 91 and 193 denote bearings 207A for the drive shafts 12 and 14.
, And the belt pulley 192 is fixed to the drive shaft 13 (FIG. 3 shows only one of them).
A toothed drive belt 190 is hung on the belt pulleys 191, 192, 193. The toothed drive belt 190 has tension pulleys 21a, 21b and a tension pulley 2 that are rotatably arranged on both sides of a belt pulley 192.
2, the driving means 19
To prevent transmission loss of the driving force to the main drive rollers 6A, 7A, 8A.

To the drive shafts 12, 14, gears 201, 202 constituting the drive means 20 on the auxiliary drive side are fixed. Sleeves 201a, 202a of gears 201, 202
Are provided with pins 201b and 202b extending in the radial direction so as to pass through the drive shafts 12 and 14, respectively. The pin 202b is arranged within a rotation range of a protrusion 193a provided on the belt pulley 193 and extending in the axial direction, and can be engaged with the protrusion 193a by rotation of the pulley 193.

At the outermost end of the drive shaft 12, the drive shaft 1 is manually
A knob 39 for rotating 2 is fixed. Gear 20
1 and the frame 1A, the gear 203 has a bearing 207B.
It is rotatably supported via. On the gear 203,
As shown in FIG. 4, an opening 203 a into which a protrusion 191 a protruding from the belt pulley 191 is inserted, and a protrusion 203 b capable of engaging with a pin 201 b of the gear 201 are formed. The pin 201b is arranged within the rotation range of the protrusion 203b.

That is, the gear 203 is connected to the belt pulley 19
1, and when the projection 203b and the pin 201b are engaged with each other, the gear 201 is integrally rotated to rotate the main drive roller 6A. The gear 202 rotates when the belt pulley 193 rotates and the projection 193a engages with the pin 202b, and rotates the main drive roller 8A. The pins 201b and 202b serve as the standby pieces,
Reference numerals 3b and 193a form movable pieces, and constitute engagement means 200A and 200B, respectively, for causing the rollers to idle within a certain range.

A large-diameter pulley 194 is fixed to the drive shaft 13. An endless timing belt 196 a is attached to the large-diameter pulley 194.
And a small-diameter pulley 195 fixed thereto.

As shown in FIG. 3, the auxiliary driving rollers 6B and 8B are provided with a pair of bearings 18 on the frame 1A and the frame 1C.
The sub-drive roller 7B is fixed to the drive shaft 16 supported by the pressing and moving means 3 by being fixed to the drive shafts 15 and 17 supported via d and 18e, respectively. Drive shaft 12,
The drive shaft 15 and the drive shafts 14 and 17 are between fixed shafts that contact the main drive roller 6A and the sub-drive roller 6B and the peripheral surfaces of the main drive roller 8A and the sub-drive roller 8B such that they do not deform.

The drive shafts 15 and 17 are provided with gears 201 and 20 respectively.
The gears 204 and 205 meshing with 2 are fixed respectively. As shown also in FIG.
A first pulley 231 having a gear 206 constituting a part of both the driving means 20 and the driving force buffering means 23 is rotatably supported between the frame 4 and the frame 1A via bearings 208A and 208B. The gear 206 is a gear 20 on the main drive side.
3 is engaged.

A second pulley 233 is fixed to the drive shaft 16. The second pulley 233 and the toothed pulley 231
Are formed with two circumferential grooves 231a and 233a, respectively, and two round belts 232 are wound around each groove. The round belt 232 has elasticity,
The expansion and contraction force is set so that the round belt 232 expands and contracts with respect to the first pulley 231 and the second pulley 233 when a rotation difference between the main drive roller 7A and the sub drive roller 7B occurs. In other words, the round belt 232 buffers the driving force transmitted to the sub-main driving roller 7B by the belt driving means 20 and applies the main driving roller 7A to the main driving roller 7A when an overload is input from the card C to the second conveying roller pair 7. On the other hand, the sub-main drive roller 7
B is made to follow. Here, round belt 2
Although 32 is used, the present invention is not limited to this, and may be, for example, an elastic flat belt. In this case, there is no need to provide a circumferential groove as in the case where the round belt 232 is used for the pulley around which the flat belt is wound.

Next, the pressing and moving means 3 will be described.
The pressing and moving means 3 connects the sub drive roller 7B to the main drive roller 7B.
A, which movably supports and presses against A, includes a pad arm 30 for supporting the drive shaft 16 and a compression coil spring 32, as shown in FIGS. The pad arm 30 has a U-shaped cross section and extends in the card transport direction (the direction of arrow A). The base end 301 of the pad arm 30 is disposed on the card insertion slot 2a side, and is swingably supported by the shafts 31 on the frames 1A and 1C. The drive shaft 16 is rotatably supported at the free end 302 of the pad arm 30 via bearings 37 and 38 on the side surfaces 30a and 30b. Drive shaft 1
Numeral 6 protrudes out of the medium transport path 2 from an opening 1E provided in the frame 1A, which is larger than the coaxial diameter, and has a structure for preventing interference with the frame 1A during movement.

On the pad arm 30 located above the drive shaft 16, an arm guide shaft 33 is disposed to penetrate upward through a spacer 36. Arm guide shaft 3
A screw portion 33a is formed on the upper end side of 3 as shown in FIG. The screw portion 33a is screwed into a pad frame 1D formed on the frame 1A, and movably supports the pad arm 30 on the free end 302 side. A lock nut 35 for preventing loosening is screwed into the screw portion 33a from above the pad frame 1D.

A compression coil spring 32 is provided between the lower surface 1Da of the pad frame 1D and the upper surface 30c of the pad arm 30.
Are arranged so as to surround the arm guide shaft 33, and urge the drive shaft 16 downward to generate a pressing force on the card C. A groove 33b is formed at the end of the arm guide shaft 33. As shown in FIG. 5, a tool 40 is inserted into the groove 33b and rotated, so that the main drive roller 7A and the sub drive roller 7B are rotated. Adjustment of the interval with

The card C and the magnetic heads 4 and 5 will be described. FIG. 11 shows the magnetic card C in this embodiment.
A thick card C1 represented by a credit card or the like provided with a magnetic stripe C1a shown on the upper or lower surface of the card shown in FIG. 11A, a prepaid card provided with a magnetic stripe C2a shown on the lower surface of the card shown in FIG. And a thin card C2 represented by The magnetic head 4 corresponds to the thick card C1, and the magnetic head 5 corresponds to both the thick card C1 and the thin card C2.
A magnetic recording signal is transmitted and received by contact with the second magnetic stripes C1a and C2a. The magnetic head 4 is urged toward the magnetic head 5 by pressing means (not shown). The magnetic heads 4 and 5 are provided with a second drive roller pair 7.
In the axial direction. That is, the first and third drive roller pairs 6 and 8 are arranged before and after the magnetic heads 4 and 5 in the transport direction. As shown in FIG. 5, the width of the medium transport path 2A near the second drive roller pair 7 in the card thickness direction is reduced. This width is set slightly larger than the thickness of the thick card C1 so that the magnetic card C can contact the magnetic heads 4 and 5 as perpendicularly as possible.

The operation of the medium transport device 1 having such a configuration will be described. When the magnetic card C is inserted into the card insertion slot 2a and a magnetic signal is detected by the card detection means 9 or 10, the drive motor 11 is started and the magnetic card C is transported in the card transport direction A here. At 1, the shutter is rotated clockwise, and at the same time, a shutter member (not shown) is retracted from the medium transport path 2. The rotation of the drive motor 11 is controlled by the large-diameter pulley 19 via a timing belt 196.
4, the drive shaft 13 rotates and the main drive roller 7A
Is driven to rotate.

The rotation of the drive shaft 13 is transmitted to belt pulleys 191 and 193 via a toothed belt 190. When the belt pulley 191 rotates, as shown in FIG. 4, it is transmitted to the drive shaft 16 from the second pulley 233 shown in FIG. The driving roller 7B is driven to rotate.
When the gear 203 rotates and the projection 203b engages with the pin 201b, the gear 201 rotates and the drive shaft 12 rotates, and the drive shaft 15 rotates via the gear 201 and the gear 204, so that the main drive gear 6A And the auxiliary drive roller 6B is rotationally driven.

The belt pulley 193 rotates and the protrusion 193
When a is engaged with the pin 202b, the gear 202 rotates to rotate the drive shaft 12, and the gear 202, the gear 20
5, the drive shaft 17 rotates, the main drive roller 8A and the sub drive roller 8B rotate, and the first, second, and third drive roller pairs 6, 7, and 8 are driven. The inserted magnetic card C is sandwiched in the order of the first, second, and third drive roller pairs 6, 7, and 8 and is transported in the medium transport path 2. In the middle, the card type (thick card C1, The magnetic recording signal is transmitted and received by one of the magnetic heads 4 and 5 by the thin card C2).

When the magnetic card C is conveyed from the first driving roller pair 6 to the second driving roller pair 7, the pad arm 30 with respect to the shaft 31 resists the urging force of the compression coil spring 32 as shown in FIG. And swings in the direction of arrow B, and the sub-drive roller 7B is lifted as shown by the two-dot chain line. The main drive roller 7A and the sub-drive roller 7B have the same effective hardness and the sub-drive roller 7B is displaced upward. Therefore, even when a thick card C1 or a thin card C2 having a different thickness is conveyed, the main drive roller 7A and the sub-drive roller 7B are displaced upward. The peripheral speeds of the main drive roller 7A and the sub drive roller 7B are the same,
The conveyance speed at the time of passing through the section is stabilized. Therefore, the recording and reproducing of the magnetic card C in the medium transport device 1 which transports the magnetic card C having a different thickness by a double-sided driving method can be performed stably.

If the load from the magnetic card C to be conveyed is applied more to the sub-drive roller 7B than to the main drive roller 7A, for example, the peripheral speed of the sub-drive roller 7B becomes smaller than the peripheral speed of the main drive roller 7A. As shown in FIG. 7, the auxiliary driving roller 6 of the first driving roller pair 6 is attached to the auxiliary driving roller 7B as shown in FIG.
The round belt 232 transmitting the driving force from B expands and contracts with respect to the first pulley 231 and the second pulley 233, so that the driving force applied to the sub-drive roller 7B is reduced, and the peripheral speed difference is absorbed.

On the other hand, since the driving force is transmitted to the main driving roller 7A by the toothed driving belt 190, the round belt 232
It is harder to slip than it is. That is, the main drive roller 7
The driving force for A becomes larger than the driving force for sub-drive roller 7B. Therefore, the card C held between the second drive roller pair 7 is conveyed under the control of the main drive roller 7A having a large driving force, and the peripheral speed difference between the main drive roller 7A and the sub drive roller 7B is reduced. Even when this occurs, the magnetic card C can be stably conveyed, and recording / reproducing defects of the card C can be reduced.

Next, the relationship between the first driving roller pair 6, the second driving roller pair 7, and the third driving roller pair 8 will be described.
Main drive rollers 6A, 7A, 8A and sub drive rollers 6B, 7
B and 8B, respectively, before transporting the magnetic card C,
The rollers are arranged so that their peripheral surfaces are located on the same plane line O. Each of the sub-drive rollers 6B, 8B of the first and third drive roller pairs 6, 8 is opposed to the main drive roller 6A,
The amount of deformation of the entire roller when the same pressing force is applied than that of 8A is larger, that is, the effective hardness is set lower. The main drive rollers 6A, 7A, 8A and the sub drive roller 7B are set to have a smaller deformation amount of the entire roller when the same pressing force is applied than the sub drive rollers 6B, 8B, that is, the effective hardness is set higher. ing. Table 1 shows the relationship between these rollers.

[0027]

[Table 1]

When such a roller relationship is set, the sub-drive rollers 6B and 8B are set to have a lower effective hardness than the sub-drive roller 7B and the main drive rollers 6A, 7A and 8A. Since the drive shafts 14 and 17 are between the fixed shafts with respect to the frame 1A,
Regardless of the type of the card C, as shown in FIG. 9, it deforms more than the main drive rollers 6A and 8A facing each other. Therefore, the first and third drive roller pairs 6 and 8 are
When a peripheral speed difference occurs between B and 8B and the main drive rollers 6A and 8A, the peripheral speed difference is absorbed by deformation of the sub-drive rollers 6B and 8B, so that the transport speed of the magnetic card C is stabilized. . Further, even if one of the driving rollers (here, the sub driving rollers 6B, 8B) is not urged to the main driving rollers 6A, 8A by a pressing mechanism or the like, the pad pressure is applied to the card C by the deformation of the sub driving rollers 6B, 8B. Therefore, it is possible to prevent an increase in the number of parts and an increase in the complexity of the device, and to suppress an increase in the size of the device.

In the embodiment described above, the main drive roller 6A,
Although there is a difference in the amount of deformation (effective hardness) between 7A, 8A and the sub-drive rollers 6B, 7B, 8B, as shown in Table 2,
The diameter of each drive roller pair may be given a difference in advance. In addition,
The amount of deformation (effective hardness) of each of the primary and secondary drive rollers is set to the conditions shown in Table 1.

[0030]

[Table 2]

For example, with respect to the diameter Y1 of the main drive roller 7A shown in FIG. 8, the diameter X1 of the main drive roller 6A, 8A,
Z1 is set small, the diameter Y1 of the main drive roller 7A and the diameter Y2 of the sub drive roller 7B are set to be the same, and the peripheral speeds of the main drive rollers 6A and 8A are set lower than the peripheral speed of the main drive roller 7A. . In this case, each drive shaft rotates at the same rotation speed. Then, when the magnetic card C to be conveyed is transferred from the first and third driving roller pairs 6 and 8 to the second driving roller pair 7, the magnetic card C is conveyed under the control of the peripheral speed of the main driving roller 7A, and is conveyed. 5 is conveyed at a constant conveyance speed. Therefore, the first and third drive roller pairs 6,
8, even if the transport speed of the magnetic card C fluctuates.
Recording and reproduction can be performed stably.

Under the condition of the roller diameter described above, the diameters X1 and Z1 of the main drive rollers 6A and 8A are
The diameters X2 and Z2 of B and 8B are set slightly larger so that when the magnetic card C is inserted between the rollers and the rollers are deformed, the diameters X1 and Z1 of the main driving rollers 6A and 8A become the same as the diameters X1 and Z1. Set. With this setting, the main drive rollers 6A, 7A, 8A and the sub drive rollers 6B, 7B, 8B are driven, and the magnetic card C is held between the first and third drive roller pairs 6, as shown in FIG. Then, the auxiliary drive roller 6B
The magnetic card C is conveyed toward the second drive roller pair 7 at a constant conveyance speed by absorbing the peripheral speed difference between the main drive roller 6A and the sub drive roller 6B.

When the magnetic card C is sandwiched between the third driving roller pair 8, the sub driving roller 8B is crushed, and the peripheral speed difference between the main driving roller 8A and the sub driving roller 8B becomes the same as the first driving roller pair 6. Absorbed. Therefore, when the magnetic card C is inserted from the third driving roller pair 8 side or when the card is reciprocated, the card C is conveyed to the second driving roller pair 7 at a constant speed.

When the magnetic card C is conveyed and nipped from the first drive roller pair 6 to the second drive roller pair 7 as shown in FIG. 10, the second drive roller pair 7 is more susceptible to the roller diameter relationship. Since the peripheral speed is set faster, the card C is delivered by being pulled from the first drive roller pair 6 to the second drive roller pair 7, and is controlled by the peripheral speed of the second drive roller pair 7. Transported. As described above, the card transport speed on the medium transport path 2 is stabilized by setting the roller diameter, so that the recording and reproduction of the magnetic card C can be performed stably.

Since the main drive roller 7A and the sub drive roller 7B are set to have the same effective hardness and the same diameter, they are similarly deformed when a pad pressure is applied. The main drive rollers 6A and 8A are configured to have the same effective hardness as the main drive roller 7A and the sub drive roller 7B, and the sub drive roller 6B and the sub drive roller 8B are lower in effective hardness than the main drive rollers 6A and 8A. (Easily deformed) is set. Therefore,
Even if the environment such as temperature changes, the first and third
The difference in the amount of roller deformation between the driving roller pair 6, 8 and the second driving roller pair 7 also fluctuates, so that the magnetic card C can be stably conveyed even over time and recording / reproducing defects are reduced. can do. This leads to an improvement in the durability of the medium transport device 1.

In addition, the first driving roller pair 6 and the third driving roller pair 8 having a lower peripheral speed than the second driving roller pair 7 are provided with the engagement means 200A and 200B. When the card C is conveyed from the first driving roller pair 6 or the third driving roller 8 toward the second driving roller 7 and enters the second driving roller, the card C includes a driving main driving roller 7A and a sub driving roller 7B. A driving force is provided from above and below. Then, the main and sub drive rollers 6A, 6B of the first drive roller pair and the main and sub drive rollers 8A, 8B of the third drive roller pair are driven by the drive shafts 12, 15, and 14,
7 and the projection 203b and the pin 201
b and the projection 193a and the pin 202b are temporarily disengaged from each other. That is, the first drive roller pair 6 and the third
The drive roller pair 8 idles with respect to the drive means 19 and 20.

Therefore, the first driving roller pair 6 or the third driving roller pair 6
The driving roller pair 8 is driven by the second driving roller pair 7, and only the driving force of the second driving roller pair 7 is transmitted to the magnetic card C. Accordingly, when the card C is conveyed in the vicinity of the magnetic heads 4 and 5, the card C does not receive the interference of the conveying force of the first and third driving roller pairs 6, 8 and responds to the peripheral speed of the second driving roller 7. Since the magnetic card C is transported at the transport speed, fluctuations in the transport speed of the magnetic card C are reduced, the transport speed is stabilized, and defective recording and reproduction are reduced.

Further, even if the roller diameter of the driving roller pair 6, 7, 8 changes due to the influence of the temperature or the like, the peripheral speed of the second driving roller pair 7 does not constantly increase. The peripheral speed is set to be higher than that of the roller pair 6, 8 and the first and third drive roller pairs 6, 8 are engaged with the engagement means 200A,
By providing 200B, the gap between each pair of conveying rollers 6, 7, 8 can be made zero. Therefore, the thickness of the magnetic card C to be conveyed is different, so that a sufficient conveying force can be given to the card C by deformation of each of the conveying roller pairs 6, 7, 8 and near the magnetic heads 4, 5, Engaging means 2
By the action of 00A and 200B, the sheet can be transported at a transport speed corresponding to the peripheral speed of the second transport roller 7 without being affected by the transport speed of the first and third transport roller pairs 6 and 8. Therefore, recording and reproduction by the magnetic heads 4 and 5 can be performed stably.

In this embodiment, in order to make the peripheral speed of the second transport roller pair 7 faster than the peripheral speed of the other transport roller pairs 6 and 8, as shown in FIG. 8, the main drive rollers 6A and 8A Diameter X
2, Z2 is set smaller than the diameter Y2 of the main drive roller 7A, but is not limited to this. For example, the gear ratio of the drive means 19, 20 to the first and third transport roller pairs 6, 8 is changed to change the first and third transport roller pairs 6, 8
Is lower than the peripheral speed of the second conveying roller pair 7,
Alternatively, a driving means having the same roller diameter for each of the transport roller pairs 6, 7, 8 and providing the first and third transport roller pairs 6, 8 and the second transport roller pair 7 with individual drive motors having different rotation speeds. , The peripheral speed of the second transport roller pair 7 may be set faster than the peripheral speed of the first and third transport roller pairs 6 and 8. Also in these cases, the effective hardness of the main drive roller 7A and the auxiliary drive roller 7B of the second transport roller pair 7 is set higher than the actual hardness of the main and auxiliary drive rollers of the other transport roller pairs, and the roller deformation amount is set. It is important that the peripheral speed of the second conveying roller pair 7 be stabilized while maintaining a small value.

In the embodiment, the main driving rollers 6A, 7A, 8A
Are located above the medium transport path 2 and are provided with sub-drive rollers 6B, 7B, 8
B has been described as an example disposed below the medium transport path 2, but the present invention is not limited to this, and the main and sub drive rollers may be disposed upside down. In short, the present invention can be applied to any pair of double-sided drive type conveyance rollers that hold the magnetic card C from both sides and apply a driving force. Further, the medium transport device 1 in this embodiment is a one-way transport system (arrow A).
However, the present invention may be applied to a medium transport apparatus of a type in which the magnetic card C is reciprocated on the medium transport path 2 using a motor capable of rotating forward and backward as a drive source.

Although the recording medium of the present invention has been described with reference to the magnetic card C in the embodiment, the recording medium is not limited to the magnetic card alone, but may be a magnetic IC card in which an IC chip is provided on a magnetic card or an optical information card. Of course, a plate-shaped recording medium capable of recording and reproducing the information may be used. In the embodiment, the magnetic heads 4 and 5 are used as the information recording / reproducing head of the present invention. However, the information recording / reproducing head is a head capable of recording / reproducing light or a magneto-optical signal or a head such as an IC contact corresponding to the above-mentioned card. Is also good.

[0042]

According to the first aspect of the present invention, when a peripheral speed difference occurs between the main driving roller and the sub driving roller, the driving force to the sub driving roller is released by the elastic belt. The peripheral speed difference between the main drive roller and the sub drive roller is absorbed, and the recording medium nipped and conveyed by both rollers can be stably conveyed. According to the second aspect of the present invention, the pressing force applied to the recording medium by the pressing and moving means can be made constant, so that the recording medium can be transported more stably. Further, since the sub-drive roller is supported by the pressing and moving means so as to be displaceable and movable, it is possible to cope with both thin recording media and thick recording media. According to the third aspect of the present invention, the peripheral speed of the main drive roller and the sub-drive roller during medium conveyance is constant, so that the recording medium can be conveyed more stably.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a medium conveyance device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a main driving roller and a driving unit thereof.

FIG. 3 is a plan view showing a schematic configuration of a sub-drive roller and its driving unit, and a pressing and moving unit and a driving force buffering unit.

FIG. 4 is a front view showing a configuration of a driving force buffering unit.

FIG. 5 is a side view showing the configuration of the pressing and moving means.

FIG. 6 is a partially cutaway front view showing the configuration of the pressing and moving means.

FIG. 7 is an enlarged view showing the operation of the driving force buffering means.

FIG. 8 is an explanatory diagram showing a relationship between a main drive roller and a sub drive roller.

FIG. 9 is a side view showing a state in which a recording medium has entered a first and third drive roller pair.

FIG. 10 is a side view illustrating a moving state of a recording medium from a first driving roller pair to a second driving roller pair.

FIG. 11 is a plan view of a recording medium applied to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 medium transport device 3 pressing and moving means 7 drive roller pair 7A main drive roller 7B sub drive roller 19, 20 drive means 232 telescopic belt C recording medium Y1 diameter of sub drive roller Y2 diameter of main drive roller

Claims (3)

(57) [Claims] 1. A recording medium comprising: a main drive roller driven integrally with a drive unit by a drive unit; and a sub drive roller connected via an elastic belt interposed between the drive unit and the main drive roller. A medium conveying device comprising at least one pair of drive rollers for nipping and conveying the sheet. 2. The apparatus according to claim 1, wherein said auxiliary drive roller is movable with respect to said main drive roller, and said pressing means is provided for applying a pressing force to said recording medium by movement of said auxiliary drive roller. Media transport device. 3. The medium transport apparatus according to claim 1, wherein the main drive roller and the sub drive roller have substantially the same diameter, and have the same amount of deformation when the same pressing force is applied. .