JPH06135075A - Printing apparatus - Google Patents

Abstract

PURPOSE:To positively set a cut paper or a continuous paper and to smoothly feed the paper in the reverse direction by providing a friction plate which urges a cut paper guiding member to a platen when each pinch roller in pressed contact with the platen is rotated forward following the forward rotation of the platen. CONSTITUTION:A paper detecting sensor 7 capable of detecting each paper is set at a paper guiding face 5. A first and a second pinch rollers 11, 12 are also provided to be freely brought in touch and out of touch to the outer peripheral surface of a platen 1. Moreover, a cut paper guiding member 21 is provided. A base end 22 of the member 21 is supported in the rotatable fashion in the vicinity of an entrance 6 of the paper guiding face 5 and, a front end 23 of the member 21 is formed to be positioned upstream of the sensor 7 in the transferring direction of the cut paper. When the rollers 11, 12 while in pressed contact with the platen 1 are rotated forward following the forward rotation of the platen 1, a friction plate 31 urges the member 21 towards the platen 1 from the free state with using the rotating force of the roller 11 as a driving source. When the rollers 11, 12 are rotated backward, the friction plate 31 retreats the member 21 from the platen 1 thereby to position the member 21 at a standby position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus capable of selectively printing cut sheets and continuous sheets.

[0002]

2. Description of the Related Art Conventionally, as a printing device, one capable of selectively printing cut paper and continuous paper with one device is known. Such printers are roughly classified into two types, which are shown in FIGS. 5 and 6. First, the printing apparatus (first conventional printing apparatus) shown in FIG. 5 will be described. In the figure,
Reference numeral 1 is a platen, and 2 is a print head, which is disposed opposite to the platen 1 and is in the longitudinal direction of the platen 1 (direction perpendicular to the plane of the drawing).
It is configured to reciprocate. A paper guide surface 5 is formed so that both cut paper and continuous paper can be guided along the outer peripheral surface of the platen 1. At the entrance portion 6 of the paper guide surface 5, a paper detection sensor 46 for detecting continuous paper sent from the tractor 8.
Is provided. 41A is a cut sheet guide member. A pinch roller 42 is rotatably supported by the cut sheet guide member 41A so as to be in pressure contact with the outer peripheral surface of the platen 1, and a sheet for detecting the cut sheet is provided upstream of the pinch roller 42 in the cut sheet conveying direction. A detection sensor 45 is provided. Note that FIG.
Reference numeral 9 denotes a deflector that prevents the sheet from rising near the printing unit 3.

However, when the cut sheet is conveyed on the cut sheet guide member 41A and the leading edge of the sheet is detected by the sheet detection sensor 45, the sheet is moved by the platen 1 and the pinch for a predetermined length from the detection position. It is conveyed by rollers 42 and positioned at a predetermined set position.
After being set, the cut sheet is conveyed on the sheet guide surface 5 by the platen 1 and the pinch roller 42 and is supplied to the printing unit 3 via the deflector 9 to be printed.

At this time, the cut sheet may be reversely fed in order to print a graph or the like. This reverse feeding is performed by rotating the platen 1 in the counterclockwise direction in FIG. 5 on condition that the sheet detection sensor 45 detects the cut sheet.

Further, the paper guide surface 5 is moved by the tractor 8.
When the leading edge of the continuous sheet fed toward the sheet is detected by the sheet detection sensor 46, the sheet is fed by a predetermined length from the detection position and positioned at a predetermined set position. After that, the continuous paper is conveyed on the paper guide surface 5 and is supplied to the printing unit 3 for printing. When the continuous paper is fed in reverse, the motor driving the tractor 8 is rotated in reverse.

On the other hand, the printing apparatus (second conventional printing apparatus) shown in FIG. 6 has a platen 1 having the same structure as the first conventional printing apparatus.
In addition to having the print head 2, the paper guide surface 5, the tractor 8, the deflector 9 and the like, the cut paper guide member 41B, the first and second pinch rollers 43 and 44, and the pinch roller contact / separation mechanism 15A are included.

The cut sheet guide member 41B is formed long in the cut sheet conveying direction so as to divide the sheet guide surface 5 and the outer peripheral surface of the platen 1 into two parts. Further, the pinch rollers 43, 44 are pressed against the outer peripheral surface of the platen 1 at the time of feeding cut paper by using the pinch roller contacting / separating mechanism 15A (pinch roller holder 16, pressure contact spring 17, etc.), and at the time of continuous paper feeding, the platen rollers are pressed. It is configured to be separated from 1.

When printing a cut sheet, however, the platen 1 is rotated clockwise in FIG. 6 while being in pressure contact with the pinch rollers 43 and 44, and is fed onto the cut sheet guide member 41B. Is conveyed in cooperation with the pinch roller 43 until the leading edge of the sheet is detected by the sheet detection sensor 47. In this way, the cut paper set in the predetermined position is loaded with the platen 1, the pinch rollers 43,
The sheet 44 is conveyed on the cut sheet guide member 41B and is supplied to the printing unit 3 for printing. At this time, the cut sheet may be reversely fed by rotating the platen 1 counterclockwise in FIG. 6 on condition that the sheet detection sensor 47 detects the sheet.

Further, the continuous paper is fed to the printing unit 3 and printed by the same method as in the first conventional printing apparatus. Also, it is sent backward.

[0010]

By the way, in the above-mentioned first conventional printing apparatus, since the paper detection sensor 45 is installed on the upstream side of the pinch roller 42 in the layout, the cut paper is straight with respect to the pinch roller 42. Even if it is not set to (that is, even if it is set to be tilted), it may be judged to be set normally. Further, when the continuous paper is fed backward, the perforations may get caught on the tip of the cut paper guide member 21. Further, since the sheet detection sensor 45 for detecting the cut sheet and the sheet detection sensor 46 for detecting the continuous sheet are provided, it is difficult to reduce the cost.

On the other hand, in the second conventional printing apparatus, the cut sheet guide member 41B must be formed long in the cut sheet conveying direction, and moreover, in the narrow sheet conveying path portion between the platen 1 and the sheet guide surface 5. Since it is necessary to dispose the platen 1 without interfering with the platen 1 or the like, a high processing precision is required and the cost tends to increase.

Therefore, under the present situation where further improvement in printing performance is required, it is an urgent need to develop a technique capable of smoothly feeding back each sheet while ensuring the setting of each sheet and reducing the cost. ing.

In view of the above circumstances, an object of the present invention is to provide a printing apparatus capable of smoothly and reliably reverse feeding cut paper and continuous paper while ensuring reliable setting of cut paper and continuous paper and cost reduction. To do.

[0014]

A printer according to the present invention has a platen and a print head which are arranged to face each other,
In a printing device configured to print by selectively feeding cut paper and continuous paper to a printing section between the print head and the platen, both the cut paper and continuous paper can be printed along the outer peripheral surface of the platen. Paper guide surface that guides the paper, a paper detection sensor that can detect cut paper and continuous paper on the paper guide surface, and the outer circumference of each platen upstream and downstream of the paper detection sensor when feeding cut paper A pinch roller that is pressed against the surface and is retracted from the outer peripheral surface of the platen during continuous paper feeding, and is retracted to the outside of the paper transport path, and the base end is rotatably supported near the entrance of the paper guide surface. And a cut sheet guide member formed so that its front end is located upstream of the sheet detection sensor in the cut sheet conveying direction, and the first and second pinch rollers. When the plate is brought into contact with the platen and is normally rotated following the normal feed rotation of the platen, the cutting paper guide member is biased from the free state toward the platen by using the rotational force of the first pinch roller as a drive source and is rotated in the reverse direction. In this case, an interlocking member for retracting from the platen and positioning at the standby position is provided.

[0015]

According to the present invention having the above-described structure, when printing cut sheets, the platen is normally fed and rotated while being in pressure contact with the first and second pinch rollers. As a result, each pinch roller is made to follow forward rotation (rotate in the opposite direction to the platen). Then, the interlocking member urges the cut paper guide member toward the platen using the rotational force of the first pinch roller as a drive source. Next, the cut sheet fed on the guide member in that state is smoothly inserted between the first pinch roller and the platen, and the leading end portion thereof is detected by the sheet detection sensor by the platen and the pinch roller. It is sent until it is set to the predetermined position.

Since the paper detection sensor is installed downstream of the first pinch roller in the cut paper conveyance direction, if the cut paper is not set straight on the pinch roller, the paper detection is performed. Since it does not, the situation in which the cut sheet is inclined and set with respect to the pinch roller does not occur.

In this way, the cut sheet set at the predetermined position is conveyed on the sheet guide surface by the platen and the first and second pinch rollers and is sent to the printing section for printing. At this time, when the platen is rotated in the direction opposite to the forward feed rotation to reversely feed the sheet with the rear end of the cut sheet positioned between the first and second pinch rollers,
Each pinch roller is rotated in reverse. As a result, the interlocking member positions the cut paper guide member at the standby position by using the rotational force of the first pinch roller as a drive source to separate the cut paper guide member from the platen. Therefore, at the time of reverse feeding, the rear end of the cut sheet is not caught on the front end of the cut sheet guide member.

When printing continuous paper, the first and second pinch rollers are separated from the platen. Next, in this state, the continuous paper is set on a paper guide surface by a tractor or the like until the leading edge of the continuous paper is detected by the paper detection sensor and set at a predetermined position. After setting, the continuous paper is conveyed on the paper guide surface and supplied to the printing unit for printing. When feeding continuous paper, each pinch roller is retracted out of the paper transport path and the cut paper guide member is in a free state, so continuous paper can be fed backward without being disturbed by pinch rollers or the like. You can

Further, since the cut sheet guide member is positioned at the standby position when the cut sheet is fed backward, the rear end portion of the cut sheet does not have to be long in the cut sheet conveying direction as in the second conventional printer. Will not be caught in. As a result, it is possible to reduce the size of the guide member and facilitate the processing, and it is possible to achieve cost reduction.

Further, as described above, since one sheet detection sensor detects cut sheets and continuous sheets, cost reduction can be achieved.

As described above, the cut paper and continuous paper can be smoothly and reliably fed backward while ensuring the setting of the cut paper and continuous paper and reducing the cost.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. The printing apparatus is formed so that cut sheets and continuous sheets can be selectively printed. Specifically, this printing apparatus has a platen 1, a print head 2, and the like having the same configuration as a conventional printing apparatus, a paper guide surface 5 provided with a paper detection sensor 7 for detecting each paper, and a platen. 1, the first and second pinch rollers 11 and 12 provided so as to be able to come into contact with and separate from each other, and the base end portion 22 has the inlet portion 6 of the paper guide surface 5.
When the platen 1 is pressed against the cut paper guide member 21, which is rotatably supported in the vicinity and is formed so that the front end portion 23 is located upstream of the paper detection sensor 7 in the cut paper conveyance direction. When the platen 1 rotates normally following the normal feed rotation, the first pinch roller 1
The interlocking member (friction plate 31) that urges the cut sheet guide member 21 from the free state toward the platen 1 by using the rotational force of 1 as a drive source and retracts from the platen 1 and positions it at the waiting position when it is rotated in the reverse direction. It is configured to include and.

Here, the paper guide surface 5 is formed so that both cut paper and continuous paper can be guided along the outer peripheral surface of the platen 1. On this paper guide surface 5,
A sheet detection sensor 7 is provided so as to detect cut sheets and continuous sheets.

The first and second pinch rollers 11,
A cut sheet 12 is pressed against the platen 1 to nip and convey in cooperation with the platen 1, and is configured to be pressed against and separated from the outer peripheral surface of the platen 1 by a pinch roller contact / separation mechanism 15.

More specifically, the first pinch roller 11
Is rotatably supported by a pinch roller holder 16 of a pinch roller contact / separation mechanism 15 so as to be pressed / separated from the outer peripheral surface portion of the platen 1 upstream of the paper detection sensor 7 in the cut paper conveyance direction. The second pinch roller 12 is rotatably supported by the pinch roller holder 16 so that it can be pressed into contact with and separated from the outer peripheral surface portion of the platen 1 downstream of the sensor 7 in the sheet conveyance direction. The pinch roller holder 16 is pressed toward the platen 1 by a pressure contact spring 17.

However, when the cut sheet is fed,
The second pinch rollers 11 and 12 are pressed against the outer peripheral surface of the platen 1 by the pinch roller contact / separation mechanism 15 and are separated from the platen 1 during continuous paper feeding, and are outside the paper conveyance path (paper in FIG. 1). It is configured to be retracted below the guide surface 5).

Further, the cut paper guide member 21 has its base end portion 22 rotatably supported via a support shaft 25, and its cut paper conveyance direction length does not hinder smooth guide of cut paper. It is formed to be as short as possible. In this embodiment, the cut sheet guide member 21 is
The tip portion 23 is formed so as to be located upstream of the left outer peripheral edge of the first pinch roller 11 pressed against the platen 1 in FIG.

The cut paper guide member 21 is made of an elastic material (stainless steel thin plate in this embodiment), and its tip portion 23 is folded back as shown in FIG. This effectively prevents the trailing edge of each sheet from being caught by the leading edge 23 of the guide member 21 during reverse feeding of cut sheets and continuous sheets.

Further, as shown in FIGS. 2 and 3, the guide member 21 is provided with the pinch roller 11 so that the cut sheet can be smoothly guided to the center of the sheet guide surface 5 without interfering with the first pinch roller 11. Roller housing part 24 for housing
Are formed. Further, the tip portion 2 of the guide member 21
The sheet 3 is formed so that the cut sheet sandwiched between the first pinch roller 11 and the platen 1 does not hit the sheet even if the cut sheet undulates.

As shown in FIG. 1, the interlocking member is a friction plate 3 mounted on the lower surface of the cut paper guide member 21 in the figure.
1 is formed.

The friction plate 31 is made of a high friction material (for example, a rubber plate), and is pressed against the outer peripheral surface of the first pinch roller 11 by the weight of the guide member 21 or the like. Thus, when the first and second pinch rollers 11 and 12 are in pressure contact with the platen 1, the platen 1 is rotated in the forward direction (clockwise in FIG. 1) to follow the forward rotation (clockwise in FIG. 1). Then, the friction plate 31 is pushed upward by the first pinch roller 11 that is frictionally engaged. As a result, the cut sheet guide member 21 is biased toward the platen 1, and a part thereof is lightly contacted with the outer peripheral surface of the platen 1.

When the platen 1 is reversely rotated (counterclockwise in FIG. 1) and the pinch rollers 11 and 12 are reversely rotated (clockwise in FIG. 1), the friction plate 31 is rotated.
Is pushed down by the first pinch roller 11. As a result, the cut paper guide member 21 is separated from the platen 1, and is positioned at the standby position where the leading end portion 23 contacts the paper guide surface 5. When the pinch rollers 11 and 12 are separated from the platen 1, the cut paper guide member 21 is released from the position regulation by the first pinch roller 11 and is in a free state.

Next, the operation will be described. When printing cut paper, the platen 1 is rotated in the forward direction while being in pressure contact with the first and second pinch rollers 11 and 12. As a result, the pinch rollers 11 and 12 follow each other and are normally rotated (rotated in the opposite direction to the platen 1).

Then, the friction plate 31 is pushed up by the normal rotation of the first pinch roller 11, and as a result, the cut sheet guide member 21 is urged toward the platen 1 and a part thereof is brought into contact with the platen 1. . Next, the cut sheet fed on the guide member 21 in that state is smoothly inserted between the first pinch roller 11 and the platen 1, and the leading edge of the sheet is detected by the platen 1 and the pinch roller 11. It is sent until it is detected by and set at a predetermined position.

Since the sheet detecting sensor 7 is installed downstream of the first pinch roller 11 in the cut sheet conveying direction, if the cut sheet is not set straight on the pinch roller 11. Since the sheet is not detected, the situation in which the cut sheet is inclined and set with respect to the first pinch roller 11 does not occur.

In this way, the cut sheet set at the predetermined position is the platen 1 and the first and second pinch rollers 11, 1.
2 is conveyed on the paper guide surface 5 and is sent to the printing unit 3 for printing. At this time, the platen 1 is rotated in the direction opposite to the forward feed rotation in order to reversely feed the sheet with the rear end of the cut sheet positioned between the first and second pinch rollers 11 and 12. And each pinch roller 11, 1
2 is rotated in reverse. As a result, the guide member 21 is pushed downward in FIG. 1 by the first pinch roller 11 via the friction plate 31, is separated from the platen 1, and is positioned at the standby position. Therefore, at the time of reverse feeding, the rear end portion of the cut paper is the front end portion 2 of the cut paper guide member 21.
No more getting caught in 3.

Further, when printing continuous paper, the pinch roller contact / separation mechanism 15 is used to separate the first and second pinch rollers 11 and 12 from the platen 1 and retract them out of the paper conveying path. Next, in that state, the continuous paper is set on the paper guide surface 5 by using the tractor 8 until the leading edge of the paper is detected by the paper detection sensor 7 and set at a predetermined position. After setting, the continuous paper is conveyed on the paper guide surface 5 and is supplied to the printing unit 3 for printing. During continuous sheet feeding, the pinch rollers 11 and 12 are retracted to the outside of the sheet conveying path, and the cut sheet guide member 21 is in a free state, so that the pinch rollers 11 and 12 and the like can continuously feed the sheet. The paper can be fed backwards.

Further, since the cut sheet guide member 21 is positioned at the standby position when the cut sheet is fed backward, the rear end of the cut sheet does not have to be elongated in the cut sheet conveying direction as in the second conventional printer. The member 21 will not be caught. As a result, downsizing of the guide member 21,
Processing can be facilitated and cost reduction can be achieved.

Further, as described above, since one sheet detection sensor 7 detects cut sheets and continuous sheets, the cost can be reduced.

Therefore, according to this embodiment, the paper guide surface 5 provided with the paper detection sensor 7 capable of detecting each paper, and the upstream and downstream of the paper detection sensor 7 in the cut paper conveyance direction at the time of feeding the cut paper. The first and second pinch rollers 11 and 12 that are pressed against the outer peripheral surface of each platen 1 and are retracted from the outer peripheral surface of the platen when the continuous paper is fed, and the base end portion 22. A cut sheet guide member 21 rotatably supported in the vicinity of the entrance 6 of the sheet guide surface 5 and formed so that the front end portion 23 is located upstream of the sheet detection sensor 7 in the cut sheet conveying direction; When the second pinch rollers 11 and 12 are normally rotated following the normal feed rotation of the platen 1 when the platen 1 is in contact, the rotational force of the first pinch roller 11 is used as a drive source to cut the sheet. Platen when it is rotated reversely urges the id member 21 to the platen 1 the free state 1
Since the friction plate 31 that is further retracted and positioned at the standby position is provided, each sheet can be smoothly fed back while ensuring reliable setting of each sheet and cost reduction.

Further, the cut paper guide member 21 has a first pinch roller 1 whose tip 23 is in pressure contact with the platen 1.
1 is formed so as to be positioned on the upstream side of the left outer peripheral edge in FIG. 1, the trailing edge of the sheet does not directly hit the leading end portion 23 of the guide member 21 in reverse feeding of the cut sheet, and the sheet is smoother. You can certainly reverse.

Further, the interlocking member is the first pinch roller 11
Since the guide member 21 is formed by the friction plate 31 that is frictionally engaged with the platen 1 to urge the platen 1 toward the platen 1, the configuration can be simplified and the cost can be further reduced.

Further, since the cut paper guide member 21 is made of an elastic material (stainless steel plate), the cut paper can be elastically supported, and the paper can be more smoothly fed to and fed back to the printing unit 3.

[0044]

According to the present invention, a paper guide surface provided with a paper detection sensor capable of detecting each paper, and platen outer peripheral surfaces upstream and downstream of the paper detection sensor in the cut paper conveyance direction at the time of feeding the cut paper. The first and second pinch rollers which are pressed against the portion and are separated from the outer peripheral surface portion of the platen during the continuous sheet feeding and retracted outside the sheet conveying path, and the base end portion is rotated near the inlet portion of the sheet guide surface. The cut sheet guide member, which is movably supported and whose front end is located upstream of the sheet detection sensor in the cut sheet conveying direction, and the first and second pinch rollers are adapted to rotate the platen forward when the platen is in contact. In the case where the cut paper guide member is urged toward the platen from the free state by using the rotational force of the first pinch roller as a drive source in the case of the normal rotation following the reverse rotation. Since the structure provided with interlocking member is retracted from the Latin positioned at the standby position, the cut paper can be smoothly backward each sheet while achieving set reliably and cost reduction of the continuous paper.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an essential part of an embodiment of the present invention.

FIG. 2 is a perspective view for explaining the positional relationship between the cut sheet guide member and the first pinch roller.

FIG. 3 is likewise a view showing a cut sheet guide member.

FIG. 4 is a sectional view showing a cut sheet guide member.

FIG. 5 is a diagram for explaining a schematic configuration of a conventional printing device.

FIG. 6 is a diagram for explaining a schematic configuration of another conventional printing apparatus.

[Explanation of symbols]

 1 Platen 2 Printing Head 3 Printing Section 5 Paper Guide Surface 7 Paper Detection Sensor 11 First Pinch Roller 12 Second Pinch Roller 21 Cut Paper Guide Member 22 Base End 23 Tip Part 31 Friction Plate (Interlocking Member)

Claims (1)

[Claims] 1. A print having a platen and a print head which are disposed opposite to each other, and cut paper and continuous paper are selectively fed to a print portion between the print head and the platen so as to print. In the device, a paper guide surface that guides both cut paper and continuous paper along the outer peripheral surface of the platen, a paper detection sensor that is provided on the paper guide surface to detect cut paper and continuous paper, and cut paper A pinch roller that is pressed against the platen outer peripheral surface portions upstream and downstream of the paper detection sensor in the paper feeding direction during feeding, and is separated from the platen outer peripheral surface portion during continuous paper feeding, and is retracted outside the paper feeding path, The base end is rotatably supported near the entrance of the paper guide surface, and the front end is located upstream of the paper detection sensor in the cut paper conveyance direction. When the cut sheet guide member formed as described above and the first and second pinch rollers are normally rotated following the forward rotation of the platen when the platen is in contact with the platen, the rotational force of the first pinch roller is used as a drive source to cut the sheet. A printing apparatus, comprising: an interlocking member that urges the guide member from the free state toward the platen and retracts the platen to a standby position when the platen is reversely rotated.