JPH043752B2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The present invention relates to a recording sheet conveying method.

(Prior art) The ink in the ink layer of the ink sheet is selectively heated and melted by a thermal head in accordance with an image signal, and the heated and melted ink is transferred onto the recording sheet to obtain a recorded image on the recording sheet. The recording method is known. In such a thermal transfer recording method, the recorded image formed on the surface of the recording sheet is not printed immediately after recording because the ink that makes up the recorded image is not sufficiently cooled and solidified. If the image comes into contact with something and is rubbed, the recorded image will be damaged.

A similar problem may also occur in copying machines and the like.
In other words, the recorded image formed by powdered toner on the recording sheet is in an extremely unstable state before it is fixed, and is easily damaged if another object comes into contact with the recorded image. .

The same is true in the case of printing presses; freshly recorded images are easily damaged if they come into contact with something before the ink dries.

As mentioned above, recorded images that are easily damaged by contact with other objects are hereinafter collectively referred to as unstable recorded images.

By the way, in a thermal transfer recording device, a copying machine, a printing machine, or the like, there are cases where a recording sheet having an unstable recorded image must be conveyed along a curved path due to the layout of the device. In this case, if the curved path is such that the surface of the recording sheet, that is, the side on which the unstable recorded image is formed, is concave, the guide protruding on the side of the recorded image will cause Unstable recorded images are easily damaged.

(Objective) Therefore, the present invention aims to provide a novel recording sheet conveyance method that effectively solves such problems.

(composition) The present invention will be explained below.

The features of the present invention are as follows.

A curved path for conveying a recording sheet having an unstable recorded image on its surface is formed by two or more sets of rotary conveyance means and one or more sets of guides. This curved path is curved so that the surface of the recording sheet being conveyed is concave. The guides are arranged between the rotating conveyance means, one set of guides consisting of a front side and a back side. That is, one of the members constituting the set of guides is placed on the front side of the recording sheet being conveyed, and the other is placed on the back side.

Each rotary conveyance means is constituted by two rotary conveyance members. The rotating conveyance member may be a roller, a roller, or the like. Therefore, the rotary conveyance means may be configured by a combination of rollers, a combination of rollers, a roller and a roller, or the like.

In each rotary conveyance means, among the rotary conveyance members, the one that contacts the back surface of the recording sheet is the driving side, and the one that contacts the front surface of the recording sheet is the driven side. Further, the drive-side rotary conveying members of each rotary conveying means are driven to have the same circumferential speed.

This will be explained below using a specific example.

1 to 3 show an example of a thermal transfer recording apparatus to which the present invention is applied.

Figure 1 shows the external appearance. Figure 2 shows only the main parts of the inside of the device.

This device is designed so that the upper part of the device can be opened and closed with respect to the lower part of the device in a hinged manner.

FIG. 3 shows a state in which the upper part of the apparatus is opened relative to the lower part of the apparatus.

First, to explain the symbols appearing in FIG. 1, numeral 1 is the lid, numeral 2 is the main body, numeral 3 is the tray, numeral 4 is the cassette, and numeral 5 is the
The cover member and the symbol S each indicate a recording paper as a recording sheet.

The lid part 1 can be opened and closed with respect to the main body part 2.

Among the various parts of the apparatus, the part that is opened and closed together with the lid part 1 is the upper part of the apparatus, and the part that is fixed to the main body part 2 is the lower part of the apparatus. The tray 3 is removably attached to the lid part 1. The cassette 4 stores the recording sheets S in a stack therein, and is attached to the recording apparatus main body 2. Although plain paper is used as the recording paper S, it goes without saying that for example, a resin film or the like can be used as the recording sheet if necessary. Recording paper S can be used in various sizes, and for each size,
It is stored and used in a special cassette. Regardless of the dimensions of the recording paper S, the length of the recording paper in the direction perpendicular to the recording paper conveyance direction is called the width of the recording paper, and the direction of the length is called the width direction of the recording paper. Regardless of the size of recording paper used, the recording paper is always set in the main body 2 so that the center in the width direction is located at a fixed position. That is, the recording paper is set using the so-called center sorting method in this example of the apparatus.

The cassette 4 is provided with a magnetic pattern corresponding to the size of the stored recording paper at the engagement portion with the main body 2, and the main body 2 detects the magnetic pattern to detect the set recording paper. Detect the dimensions of
Controls the driving area of the thermal head.

In addition to the recording paper stored in the cassette, this apparatus also allows other recording sheets to be manually loaded into the apparatus for recording. The lid member 5 is adapted to open and close the entrance of the recording sheet setting section for manual feeding.

Now, to explain each part of the apparatus with reference to FIG. 2, reference numeral 11 is a paper distribution roller, numeral 12 is a paper feed roller, numeral 13 is a return roller, numeral 14 is a guide, numerals 15 and 16 are guides, and numeral 17 is a Sensors, symbols 18A and 18B are registration rollers, symbol 19
2 indicates a guide, and 20 indicates a platen roller, respectively.

Further, code IS is an ink sheet, code 21 is a guide pipe, code 22 is a buffer guide, code 23 is a guide pipe, code 24 is a guide roller, code 2
5 is a thermal head, 26 is a bracket, 27 is a relay roller, 28 is a guide, and 29 is a peeling claw.

Furthermore, codes 30A, 30B, 32A, 32
B, 34A, 34B are discharge rollers, code 31A,
31B, 33A, and 33B are guides, 35 is a control unit, 36 is a power source, 37 is a cover, 38 is a sensor, 39 is a take-up spool, and 40 is a take-up shaft.

The paper distribution roller 11 has a shaft equipped with a plurality of rollers arranged at intervals in a skewer shape, and these rollers have a rubber surface and have sufficient frictional force against the recording paper S. . This paper distribution roller 11 rotates clockwise during operation.

The paper feed roller 12 and the return roller 13 are also equipped with a plurality of rollers arranged in a skewer shape on their shafts, and the surfaces of these rollers are made of rubber, so that each roller has sufficient friction against the recording paper S. It has power. While the paper feed roller 12 rotates clockwise during operation, the return roller 13 is rotationally driven clockwise via a friction transmission mechanism.

The guide 14 is plate-shaped, and from the cassette 4,
It constitutes a conveyance path for recording paper leading to registration rollers 18A and 18B. The guides 15 and 16 are also plate-shaped and constitute a conveyance path for recording sheets that are manually set, that is, a manual conveyance path.

The sensor 17 is for detecting a recording sheet, and
The actuator 17A is placed near the confluence of the conveyance path formed by the guide 14 and the manual feed conveyance path. Of course, actuator 1
7A, guides 14, 15, 16
is cut out.

Roller 18A constituting the registration roller,
Among the rollers 18B, the roller 18A is on the driving side, and the roller 18B is on the driven side. Drive side roller 18
The surface of roller A is made of rubber, and the roller 18B on the driven side is made of stainless steel. The end of the guide 14 on the registration roller side is connected to the rollers 18A, 1.
It is set at a lower position than the contact portion 8B so that the recording paper can enter the contact portion without being obstructed. In addition, the guide 14 moves from the feeding position of the paper feed roller 12 to the registration roller 18.
It gradually rises toward the A and 18B sides.

The guide 19 includes registration rollers 18A, 18
A conveyance path from B to the platen roller 20 is configured.

The platen roller 20 is a rubber roller and can be driven to rotate intermittently in both forward and reverse directions by a step motor (not shown).

The thermal head 25 has a plate shape elongated in the direction perpendicular to the drawing, and has a large number of minute heating elements arranged in an array in the longitudinal direction of the head, that is, in the direction perpendicular to the drawing. This heating element array arrangement section is hereinafter referred to as a writing section.

The thermal head 25 is held by a bracket 26, and during recording, it is connected to the writing section and the platen roller 20 via an ink sheet IS and a recording paper S.
are in pressure contact with each other along the generatrix of the platen roller 20 in the longitudinal direction. Thermal head 2
5 and the platen roller 20 are hereinafter referred to as a recording section.

The guide 28 is plate-shaped and forms a conveyance path for the recording paper from the recording section to the discharge rollers 30A and 30B. The peeling claw 29 is auxiliary provided to ensure separation of the recording paper S and the ink sheet IS after recording.

Ejection rollers 30A, 30B, 32A, 32B, 3
4A and 34B transfer the recording paper S after recording to the tray 3.
A conveyance path for discharging upward is provided by guides 31A,
31B, 33A, and 33B.

Ejection rollers 30A, 30B, 32A, 32B, 3
4A and 34B both have a plurality of rollers mounted on the shaft in a skewed manner. The discharge rollers 30A, 32A, and 34A are on the driven side and are made of a material that is not easily stained by ink, such as resin or aluminum. The discharge rollers 30B, 32B, and 34B are on the drive side and are made of a material such as rubber that has a sufficient coefficient of friction against the recording paper. Further, these discharge rollers 30A to 34B are all set to the same feeding speed. Moreover, the feeding speed by these discharge rollers is
The feeding speed of the relay roller 27 is set higher than the feeding speed of the relay roller 27.

In the end, the recording paper S passes through the guide 14, the manual feed conveyance path, the registration rollers 18A, 18B, the guide 19, the platen roller 20, and reaches the recording section.
Guides 31A, 31B, discharge rollers 32A, 32
B, guides 33A, 33B, discharge rollers 34A, 3
4B and is discharged onto the tray 3. The recording paper transport path from the cassette 4 to the tray 3 is shown by a broken line in FIG. Immediately after the ejection rollers 30A and 30B in the recording paper transport path, a sensor 38 is provided to detect the recording paper to be ejected after recording, and the actuator 38A is inserted into the recording paper transport path. I'm letting you do it. Guide 31A, 3
1B is plate-shaped, but of course the part where the actuator 38A is placed is cut out.

On the other hand, the ink sheet IS is wound into a roll and set on the upper part of the thermal transfer recording device. For ink sheet IS, first, guide pipe 2
1, and then the guide pipe 23
After wrapping around the upper side, and then wrapping around the lower side of the guide roller 24, it reaches the recording section, passes through the relay roller 27, and then winds up on the take-up spool 3.
9 and is wound onto the take-up spool 39 by rotation of the take-up spool 39 counterclockwise by the take-up shaft 40. Note that the winding shaft 40
is provided at the bottom of the device. ink sheet IS
The conveyance path is shown by a chain line in FIG.

Now, the guide pipe 21 is rotatably provided at the top of the device. The buffer guide 22 is a rotatable pipe, and the guide pipes 21 and 23
, and comes into contact with the upper surface of the ink sheet IS, that is, the spine of the ink sheet IS. A bracket (not shown) that rotatably holds the buffer guide 22
is itself swingably held on the rotating shaft of the guide pipe 21. Therefore, the buffer guide 22 itself is swingable and can be moved between the position shown by the solid line and the position shown by the broken line. It is designed to be able to oscillate.

The guide pipe 23 is arranged at the bottom of the device and is rotatable. The guide roller 24 is disposed at the top of the device, is rotatable, is made of foamed rubber, and has a low hardness and a large outer diameter.

The relay roller 27 has a surface formed of rubber or foamed rubber that has a sufficient frictional transmission force with respect to the base sheet of the ink sheet IS, and is set at a feed speed that is 1 to 10% higher than the feed speed of the platen roller 20. .

The control unit 35 is a circuit system including a CPU, and is mainly composed of a printed circuit board.

The device also has two drive motors (not shown). One of them is the step motor mentioned above, and the others are regular motors for continuous rotation.

Here, if each part is associated with the upper part of the device and the lower part of the device, it will be as follows. As mentioned earlier,
The upper part of the apparatus can be opened and closed with the lid 1 in a hinged manner relative to the lower part of the apparatus.
Guide pipe 21, buffer guide 22, guide roller 24, thermal head 25, relay roller 2
7, discharge rollers 32A, 32B, 34A, 34B,
This is why guides 33A and 33B are provided. Also, as mentioned above, the ink sheet IS is set at the top of the apparatus. The platen roller 20 and others are located at the bottom of the device.

Therefore, as shown in Fig. 3, when the upper part of the apparatus is lifted upward, the upper part of the apparatus opens in a hinged manner with the ink sheet conveyance path (the path indicated by the chain line in Fig. 2) facing the lower part of the apparatus. It turns out.

The cover 37 is swingable around the shaft 37A, and when the upper part of the apparatus is opened, it follows the lid part 1 and rotates to the position shown in FIG. 3.

Note that the swing shaft for opening and closing the upper part of the device is
It is indicated by the symbol X in the figure and FIG.

Next, driving of each part will be explained. As mentioned above, the device has a step motor and a regular motor. These motors are arranged at the bottom of the apparatus, and among these motors, the step motor drives the platen roller 20, the relay roller 27, and the winding shaft 40. Platen roller 2
0 and the relay roller 27 are directly driven by a step motor, but the take-up shaft 40 is driven with constant torque via a friction transmission mechanism.

On the other hand, the normal motor first moves the paper delivery roller 11, the paper feed roller 12, the return roller 13, the drive side roller 18A of the registration roller, and then the side drive side of each ejection roller, that is, the ejection roller. 30
B, 32B, and 34B are driven. Of these,
Return roller 13, discharge roller 30B, 32B, 34B
is driven with constant torque via a friction transmission mechanism.

Each roller is operated according to predetermined timing by an electromagnetic clutch.

Various controls in the recording process are performed by a control unit 35. FIG. 4 shows a flow diagram of this control system.

In the figure, it is indicated by reference numeral 4-1. The part surrounded by a solid line frame indicates the thermal transfer recording device. The host system is a system that supplies image signals to the thermal transfer recording device, and is a computer, word processor, communication device, or the like. The host system and thermal transfer recording device are mediated by a video interface. In the figure, the part indicated by the symbol 4-2 surrounded by a broken line is the control unit 3.
It corresponds to 5. This control unit 35 includes a CPU,
It has a video interface, bit unit energy control circuit, RAM, head driver, pulse width determination circuit, AMP, and mechanical driver. The head driver is the thermal head 25 (second
Figure). The mechanical driver is a motor,
Drives clutches, solenoids, etc.

The recording process using this thermal transfer recording apparatus will be explained below.

As shown in Figure 3, the upper part of the apparatus is opened in a hinged manner relative to the lower part of the apparatus, and the ink sheet IS wound into a roll is set in a holding mechanism (not shown) at the upper part of the apparatus, and the ink sheet IS attached to the tip of the sheet is taken up. The spool 39 is locked to the take-up shaft 40. After that, if the upper part of the device is closed, the state shown in FIG. 2 will be obtained.

During recording, first, a lifting mechanism (not shown) operates to lift up the leading end of the recording paper S in the cassette 4. As a result, the leading edge of the topmost sheet of recording paper S comes into contact with the paper distribution roller 11.

Subsequently, the paper delivery roller 11, the paper feed roller 12, and the return roller 13 are driven, and each is rotated in the direction of the arrow. Note that since the return roller 13 is driven via a friction transmission mechanism, contact with the paper feed roller 12 causes
A slip occurs in the friction transmission mechanism, and the paper feed roller 12 rotates counterclockwise.

As the sheet distribution roller 11 rotates, the topmost sheet of recording paper S in the cassette 4 is distributed from within the cassette 4. The distributed recording paper S is transferred to the paper feed roller 12.
The paper is conveyed along the guide 14. At this time, the friction transmission mechanism of the paper feed roller 12 is slipping.

Although it is not uncommon, sometimes two or more sheets of recording paper are distributed by the paper distribution roller 11. In such a case, only the topmost sheet is fed toward the registration rollers due to the action of the paper feed rollers 12 and the return rollers 13.

That is, the conveyance force due to friction between the paper feed roller 12 and the recording paper is F _FP , the conveyance force due to friction acting between the recording paper and the recording paper is F PP , and the return roller 13 is F _PP .
Let F _RP be the _recording paper return force due to _{the friction between}
It is set so that F _FP > F _RP . In other words, the relationships F _FP > F _PP and F _RP > F _PP are established by forming the surfaces of the feed roller 12 and the return roller 13 with rubber, and the relationship F _FP > F _RP is established by forming the surfaces of the paper feed roller 12 and return roller 13 with rubber. This is achieved by setting the maximum transmission torque immediately before slippage occurs in the friction transmission mechanism that transmits rotation to the shaft 13 within a range where this relationship holds true. Because of this force relationship, when two or more sheets of recording paper are delivered and held by the paper feed roller 12 and return roller 13, the return roller 13 rotates clockwise correctly and reaches the maximum position. Except for the top one, pull the other recording papers back to the cassette 4 side. Therefore, even if a plurality of sheets of recording paper are delivered by mistake, only one sheet of recording paper is always sent to the recording section.

In order to safely transport the recording paper S, the transport speed of the paper feed roller 12 is set higher than that of the paper distribution roller 11, and the reverse transport speed of the return roller 14 is set higher than that of the paper feed roller 12. It is desirable to make it even larger.

The leading edge of the recording paper S conveyed by the paper feed roller 12 gradually advances upward along the guide 14.
Defeat actuator 17A of sensor 17,
After that, it reaches registration rollers 18A and 18B. As mentioned above, among the registration rollers, the driving side roller 18A has a rubber surface and the driven side roller 18B has a stainless steel roller.
When the registration rollers 18A and 18B enter the contact area between both rollers, the registration rollers 18A and 18B are not yet driven.
Not rotating. The leading edge of the recording paper that is being conveyed is connected to the rollers 18A and 1 by the end of the guide 14.
Since it is located below the contact part of roller 8B, it first hits the circumferential surface of the smooth and slippery stainless steel roller 18A, and slides on this circumferential surface.
The above contact area is reached smoothly.

The registration rollers 18A and 18B are driven to rotate after a predetermined period of time after the sensor 17 is turned on, but when the leading edge of the recording paper enters the registration roller contact area as before, they are still not driven. However, after the above-mentioned plunge, it is driven a little later. During this time, the paper feed roller 12 continues to transport the recording paper S, and therefore, the recording paper S whose leading end is stopped by the contact portions of the registration rollers 18A and 18B is moved between the registration rollers 18A and 18B.
A slack is formed between the paper feed roller and the paper feed roller.

Subsequently, the registration rollers 18A and 18B rotate to convey the recording paper S to the recording section.

As described above, since the recording paper S is slackened and then the registration rollers are driven to transport the recording paper, the skew of the recording paper and uneven transport speed that occur between the cassette and the registration rollers are eliminated. It can be corrected and the subsequent transport position of the recording paper can be accurately controlled.

Note that when the registration rollers 18A and 18B rotate, the paper feed rollers 12 and the like are deactivated and follow the movement of the recording paper S by free rotation.

When loading recording paper manually, use guide 1.
The recording paper is fed into the apparatus through the manual feed conveyance path indicated by 5 and 16. The fed recording paper knocks down the actuator 17A with its tip and rushes into the contact portion of the registration rollers 18A and 18B.

The registration rollers 18A and 18B start rotating a predetermined time after the sensor 17 is turned on. If this predetermined time is set to about 0.5 to 1.5 seconds, assuming that the distance from the position where the sensor 17 is turned on to the contact portion of the registration rollers 18A, 18B is 20 mm, a good operational feeling can be obtained.

The time interval from when the sensor 17 turns on to when the registration rollers are driven must be different depending on whether the recording paper is fed manually or from a cassette, and it is necessary to distinguish between these two feeding modes. There is a need to.

Now, when the registration rollers 18A and 18B rotate to send the recording paper to the recording section, the platen roller 20 rotates counterclockwise and grips the leading end of the recording paper S into the recording section. In this way, the recording paper S
is set in the recording section, registration roller 1
8A and 18B are released from driving and left in a freely rotatable state thereafter.

Subsequently, the platen roller 20 is rotated counterclockwise by intermittent driving to cause the recording paper S and the ink sheet S to run toward the thermal head 25.

At the same time, an image signal is applied to the thermal head 25, and writing is performed. In other words, the minute heating element that constitutes the writing section of the thermal head 25 generates heat in response to the image signal, and instantaneously generates heat.
The temperature rises to around 300℃. This heat is transmitted to the ink layer via the base sheet of the ink sheet IS, and the ink in the heated portion is thermally melted and transferred onto the recording paper S.

Note that, as described above, recording sheets of different sizes can be used in this recording apparatus, and these sheets are conveyed within the apparatus by a so-called center sorting method. Therefore, if the layer of the recording paper used is shorter than the length of the writing section of the thermal head 25, the image signal applied to the thermal head 25 is masked according to the width of the recording paper, and the thermal By timing the latch to the head 25, appropriate image recording is achieved depending on the width of the recording paper.

Now, the recording paper S and the ink sheet IS that have passed through the recording section are bonded together due to the adhesive force of the thermally transferred ink.
Although they are in a state where they are attached to each other, the two are separated from each other by the relay roller 27. That is,
As mentioned above, the ink sheet IS is extremely thin, so
The so-called stiffness of the ink sheet IS and the recording sheet S are greatly different. Therefore, ink sheet IS
When the conveyance direction of the ink sheet IS is suddenly changed greatly by the relay roller 27, the recording paper S cannot follow the change in the direction of the ink sheet IS due to its elastic force, that is, its stiffness, and the recording paper S automatically changes to the ink sheet IS. Separated and along the guide 28, the discharge rollers 30A, 30
It rushes into the contact area of B. The peeling claw 29 is used when separation of the two sheets fails due to some reason.
This is provided to ensure that the two are separated.

Since the middle roller 27 separates both sheets on its outer periphery, its diameter is preferably made as small as possible. When the diameter of the relay roller 27 becomes smaller, even thinner and weaker paper can be reliably separated, so that a wide variety of paper types can be used as recording paper.

The peeled ink sheet IS is then sequentially wound onto a take-up spool 39.

On the other hand, for recording paper S, discharge rollers 30A, 30
B, guides 31A, 31B, discharge rollers 32A, 3
2B, the guides 33A, 33B, and finally the tray 3 is conveyed by the discharge rollers 34A, 34B.
is discharged upwards. In this way, a desired thermal transfer recorded image is obtained.

The common tangential plane at the contact portion of the discharge rollers 34A, 34B is oriented slightly upward to the right in FIG. Therefore, the recording paper S is discharged slightly upward to the right. In this way, tray 3
Good stock is guaranteed.

Note that the sensor 38 detects the leading edge and trailing edge of the recording paper to be ejected by the fall of the actuator 38A and its return, and compares the signal with the theoretical value to determine the position of the recording paper S. In addition to detecting the occurrence of a conveyance failure, that is, a so-called jam, the recording operation completion time is determined.

Also, after writing in the recording section, the ink sheet
The IS is sent to the separation position together with the recording paper S, but if the IS is left as it is and the next recording is performed, the ink sheet portion between the recording section and the separation section will be wasted. Therefore, after the recording paper and the ink sheet are separated, the platen roller 20 is reversed, and the ink sheet portion located at the separating section and the recording section is returned to the recording section. In the case of continuous recording, the paper is pulled back after the last page of recording paper is separated.

Now, in the thermal transfer recording apparatus described above, the present invention is applied to the conveyance of the recording paper S as a recording sheet for ejecting it out of the apparatus after recording.

That is, after recording, the recording paper having an unstable recorded image is discharged out of the apparatus through a curved path in which the front side is concave.

The curved path includes discharge rollers 30A, 30B, 32
A, 32B, 34A, 34B and guides 31A, 3
1B, 33A, and 33B.

Ejection rollers 30A and 30B, 32A and 32B, 3
4A and 34B each constitute a rotary conveyance means. That is, in this example, three sets of rotary conveyance means are provided. Guide 31A, 3
1B is the discharge rollers 30A, 30B and the discharge roller 3.
It is located between 2A and 32B. Further, the guides 33A, 33B are arranged between the discharge rollers 32A, 32B and the discharge rollers 34A, 34B.

Guides 31A and 31B are one set of guides, and guides 33A and 33B are another set of guides. In each set of guides, guides 31A and 33A are
A guide 31 is placed on the front side of the recording sheet being conveyed.
B and 33B are arranged on the back side.

Ejection rollers 30A, 30B, 32A, 32B, 3
4A and 34B are rotary conveying members, and among these, 30 is in contact with the front side of the recording sheet.
A, 32A, and 34A are on the driven side, and the others are on the driving side.

The drive side discharge rollers 30B, 32B, 34B are
The platen roller 20 has a peripheral surface formed of a material such as rubber that has a sufficient frictional transmission force to the recording paper S, is driven by a normal motor via a frictional transmission mechanism, and has a peripheral speed for conveying the platen roller 20. The circumferential speed is set higher than the circumferential speed of the relay roller 27, and the circumferential speeds of the discharge rollers 30B, 32B, and 34B are equal to each other. In addition, rollers 30A and 32 on the driven side
A and 34A are made of a material that is not stained by ink, such as resin or aluminum.

First, since the circumferential speed of the discharge roller 30B is higher than that of the platen roller 20 and the relay roller 27, the recording paper S is stretched tightly on the guide 28, and wrinkles are prevented from forming in this area. Ru. In addition, the discharge rollers 30A, 32A, 34A are
Since the ink does not stain, the ink on the recording paper adheres to the ejection roller, and then again.
The so-called offset phenomenon, which occurs when images are transferred onto recording paper, can be effectively prevented.

Further, since the conveyance speed of the recording paper S by the discharge rollers 30A to 34A is the same, the recorded image formed on the recording paper S by the transfer ink is transferred to the guide 3.
It will not be rubbed by 1A and 33A.

Generally, when conveying sheet-like materials, it is common sense to set the conveyance speed higher toward the downstream side of the conveyance path to create tension in the conveyed sheet and to stabilize the conveyance. Applying this idea to the ejection path of the paper S, in the case of this device, the ejection path has a large curve, and for example, the recording paper is tensioned between the ejection rollers 30A, 30B and 32A, 32B. And the recorded image on the recording paper is
It is rubbed by the guide 31A, leaving scratch marks. Therefore, in this device, this problem is solved by making the conveyance speed of all discharge rollers equal.

(Effects) As described above, according to the present invention, it is possible to provide a recording sheet transport method that can transport a recording sheet favorably without damaging an unstable recorded image.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the external appearance of an example of a thermal transfer recording device to which the present invention is applied, FIG. 2 is a front view showing only the main internal parts of the device, and FIG. 3 is similar to FIG. FIG. 4 is a flowchart showing the control system of the apparatus shown in FIG. 1. FIG. 30A, 30B, 32A, 32B, 34A, 3
4B...Discharge roller (rotary conveyance member), 31A, 31
B, 33A, 33B...Guide.

Claims (1)

[Scope of Claims] 1. A method for conveying a recording sheet having a recorded image on its surface along a curved path in which the path is curved so that the surface side is concave, the method comprising: two or more sets of rotary conveyance means; , one or more sets of guides arranged between these rotary conveyance means and forming one set on the front side and the back side constitute a curved path, and among the rotary conveyance members constituting each rotary conveyance means, recording The drive side rotary conveyance member of each rotary conveyance means is driven to have the same circumferential speed, with the side that contacts the back side of the sheet being the drive side and the side that contacts the front side of the recording sheet being the driven side. A recording sheet conveying method.