JP2002002075A - Tension mechanism for ink ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain good image quality of a recorded paper by maintaining a speed of an ink ribbon at a constant level even when diameters of rolls change in a supplying section and a winding section in an image recording apparatus wherein the ink ribbon is inserted into a recording section together with a paper to form the recorded paper. SOLUTION: A recording section 5 comprises a platen roller 8 which is driven by a device constituted such that the ink ribbon 10 is supplied from the supplying section 11 and is wound in a winding section 15 and a recording head 6. A conveyance roller device 20 is disposed to an upstream section of the recording section 5 and the speed of the ink ribbon is maintained at a constant level by a torque limiter 23 provided to the conveyance roller device 20. The conveyance roller device 20 maintains an entering angle of the ink ribbon 10 to the recording section 5 in a constant level and stably executes an operation for guiding the paper introduced from a paper conveyance path in the recording section 5 by interposing the paper on the ink ribbon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving mechanism for an ink ribbon used in an image recording apparatus, and more particularly to a tension mechanism for an ink ribbon which can maintain a constant speed of a recording section of the ink ribbon.

[0002]

2. Description of the Related Art Conventionally, in an image recording apparatus such as a small facsimile apparatus or a printer, an apparatus of a type in which recording is performed on a sheet using an ink ribbon is used. In the image recording apparatus using the ink ribbon, the paper and the ink ribbon are overlapped and passed between the thermal head of the recording unit and the platen roller, and the heating element of the thermal head is turned on by the print information transmitted to the recording unit. By generating heat and transferring the ink carried by the ink ribbon to the paper, image information is printed on the paper. The ink ribbon is wound around a roll holder disposed in each of a supply unit and a winding unit, and is configured to drive the winding roll holder to sequentially draw out the ink ribbon from the roll holder in the supply unit. A torque limiter is provided between the take-up roll holder and the drive source, and controls the speed of the ink ribbon in the recording unit to be constant.

[0003]

In the ink ribbon driving mechanism, as the ink ribbon is used, the diameter of the ink ribbon on the feeding side decreases and the diameter of the roll holder on the winding side gradually increases. . For this reason, even if an attempt is made to maintain the speed of the ink ribbon in the recording unit constant, there is a problem that the expansion and contraction rate of the recorded image in the sub-scanning direction is not stabilized due to the influence of the change in the diameter of the rolls on both sides. Further, as the ink ribbon is wound up, the diameter of the ink ribbon held by the roll holder on the feeding side gradually decreases, so that the angle at which the ink ribbon enters the recording unit from the feeding roll holder side changes. For this reason, the relative angle between the ink ribbon and the paper entry path changes, which may cause a paper feeding failure to the recording unit, which may cause a paper jam.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism that can apply a constant tension to convey an ink ribbon regardless of the use condition of the ink ribbon, so that the angle of invasion into a recording unit is constant.

[0005]

According to the present invention, there is provided a supply member for supplying an ink ribbon, a winding member for winding the ink ribbon, and a supply member disposed between the supply member and the winding member.
The present invention relates to an apparatus including a recording unit that transfers ink ribbon to paper. The invention according to claim 1 of the present invention is characterized in that a pair of rollers for conveying an ink ribbon is provided between the supply member and the recording unit. Therefore, since a constant penetration angle can always be set for the recording unit, it is possible to prevent jamming or the like caused by biting into the platen roller or poor overlay with paper. Also,
Since the tension between the recording unit and the roller can be maintained constant, it is possible to prevent the recorded image from expanding and contracting in the sub-scanning direction.

According to a second aspect of the present invention, a torque limiter is provided on one of the pair of rollers. Then, unlike the case where the torque limiter is provided on the supply member or the winding member, the ink ribbon can be conveyed in a state where a constant tension is applied regardless of the usage state of the ink ribbon. Claim 3
In the invention, the recording section includes a platen roller rotating at a constant speed, and a thermal head resiliently provided on the platen roller, and an ink ribbon and paper are nipped between the thermal head and the platen roller. It is transported in a state where And according to the configuration,
It is possible to obtain a sheet on which high quality image is recorded.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the apparatus of the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows a case where a recording unit using an ink ribbon is used as a recording member of a facsimile machine or a printer. A device and control means for receiving an image signal, transmitting the image signal to the recording head 6 of the recording unit 5, and recording image information on a sheet are arranged. The recording head 6 is disposed on the inner frame 4 so that the paper transport path can be opened with the cover 3 of the main body frame 2 opened.

[0008] In the recording section 5, a sheet and an ink ribbon 10 are conveyed while being superposed between a recording head 6 such as a thermal head pressed by a spring 7 and a platen roller 8, and applied to the recording head 6. The ink is transferred from the ink ribbon 10 to the paper based on the record information,
Record image information on paper. The ink ribbon 10 includes:
Supply unit 11 for holding roll film on main body frame 2
And a winding unit 15 for winding the film that has passed through the recording unit. A transport roller device 20 is disposed between the supply unit 11 of the ink ribbon 10 and the recording unit 5.

The transport roller device 20 serves to maintain the angle at which the ink ribbon 10 fed from the supply unit 11 is guided toward the recording unit 5 at a constant angle, and to operate the ink ribbon 10 fed toward the recording unit 5. Is given a constant tension. Then, by rotating the platen roller 8 of the recording unit 5 at a constant speed, the image information is recorded on the paper while maintaining the speed of the ink ribbon in the recording unit 5 constant. Further, a torque limiter for controlling the transport speed of the ink ribbon 10 to be constant is disposed on each of the rolls disposed in the supply unit 11 and the rollers of the transport roller device 20. Control is performed so that the transport speed is constant.

For the ink ribbon 10 fed at a constant speed by the transport roller device 20, a paper transport path 25 is disposed upstream of the recording unit 5, and one paper is fed from a paper feed device (not shown). The sheet is fed one by one, and the sheet is overlapped on the lower surface of the ink ribbon 10 at the nip portion of the recording unit 5. Then, in the recording unit 5, the platen roller 8 is driven at the sheet feeding speed set in the image recording apparatus, and the image information is recorded on the sheet while the sheet and the ink ribbon 10 are conveyed in an overlapping manner. The ink ribbon 10 on which the image information has been recorded on the paper through the recording unit 5 is guided from the separation unit 26 formed in the shape of a knife edge toward the winding unit 15 at a steep angle. The paper having high rigidity is easily separated from the ink ribbon 10. The paper separated from the ink ribbon 10 by the separation unit 26 is discharged to a discharge tray (not shown) via a discharge roller device 27.

A member having a configuration as shown in FIG. 2 is disposed on a guide path between the supply section 11 and the winding section 15 of the ink ribbon 10. A supply unit 11 for holding the ink ribbon 10 includes a roll holder 12 having a core.
And a mechanism for disposing the torque limiter 14 with respect to the gear 13 of the roll holder 12 to feed out the ink ribbon 10 at a constant speed. In the transport roller device 20 disposed between the recording unit 5 and the supply unit 11, two rollers 21 and 22 are disposed so as to sandwich the ink ribbon 10, and a predetermined value of nip pressure is applied between the two rollers. , And a torque limiter 24 is provided on one of the two rollers so that the transport roller device 20 maintains the speed of the ink ribbon at a constant speed. For example. A gear 23 is provided on the lower roller 22 in the figure, and a torque limiter 24 is meshed with the gear 23, and the roller 2 is rotated by the torque limiter 24.
2 controls the rotation speed of the ink ribbon 1 passing through the recording unit 5.
A constant value tension can be applied to 0.

As the torque limiter 24 provided in the transport roller device 20 and the torque limiter 14 provided in the supply section 11, conventionally known torque limiter means can be used. The torque limiter provides a large braking action when the ink ribbon is at or above a certain speed, but can be configured as a device that allows the ink ribbon to move at or below a set speed. In the recording unit 5 disposed downstream of the transport roller device 20, the recording head 6 is pressed by a spring 7 at a predetermined nip pressure against a platen roller 8 driven at a constant speed. The image information is recorded on the sheet by transferring the carried ink to the sheet by the heat of the recording head 6. Further, the ink ribbon 10 that has passed through the recording unit 5 is taken up by a roll holder 16 driven by a drive gear 18.

The ink ribbon 10 is driven by driving the roll holder 16 by a driving gear 18 meshing with a gear 17.
When the conventional device is wound around the roll holder 16,
As the diameter of the film wound on the roll holder 16 increases, the speed of the ink ribbon 10 fed from the supply unit 11 gradually increases when the driving speed of the driving gear 18 is constant. Had occurred. Further, control means for controlling the feeding speed of the supply unit 11 has been arranged so that the feeding speed of the ink ribbon 10 in the supply unit 11 is kept constant. However, in the conventional device,
It is difficult to control the winding speed of the winding unit 15 to a constant speed with respect to the diameter of the roll that is gradually increased by winding the ink ribbon, and it is necessary to control the feeding speed from the supply unit 11 to be constant. The problem remained that it was also very difficult.

In order to solve the problem of the conventional apparatus as described above, in the present embodiment, the torque limiter 14 provided for the supply unit 11 causes the supply unit 11 to rotate excessively due to inertia, thereby causing the ink ribbon 10 to become excessive. Can be prevented. The feeding speed of the recording unit 5 with respect to the ink ribbon 10 is controlled by the transport roller device 2.
Only by the action of the speed control by the torque limiter 24 at 0, it is possible to accurately maintain the constant value. Therefore, the drive speed of the drive gear by the drive gear of the ink ribbon wound by the winding unit 15 is regulated by the transport roller device 20, so that the winding unit 15
Take-up unit 15 and recording unit 5
The ink ribbon 10 can be moved while maintaining a constant tension between them. When the sheet is superimposed immediately before the recording unit 5 on the moving path of the ink ribbon 10, the contact angle with the sheet between the transport roller device 20 and the recording unit 5 does not change.
The guide position of the ink ribbon 10 with respect to the recording unit 5 does not change.

The image recording apparatus 1 using the ink ribbon 10 can be constructed by incorporating it into an arbitrary apparatus, but is preferably constructed as a small facsimile apparatus. In the transport roller device 20 disposed upstream of the recording unit, if a constant speed drive mechanism is disposed for the drive roller, it is possible to easily control the feed speed for the ink ribbon. Other,
Instead of connecting the transport roller device 20 to the drive mechanism, the transport roller device 20 may be configured to control the speed with respect to the feeding action by the winding unit 15. That is, when the transport roller device 20 is not driven, the platen roller 8 of the recording unit 5 performs an operation of maintaining a constant feed speed of the ink ribbon, and the winding unit 1
Due to the winding operation at 5, the speed of the ink ribbon and the paper passing through the recording unit in an overlapping manner does not change, and the speed can always be maintained at a constant speed.

[0016]

Since the apparatus of the present invention is constructed as described above, by providing a pair of rollers for conveying the ink ribbon between the supply member and the recording section, It is possible to always set a constant penetration angle, and it is possible to prevent jamming or the like caused by biting into the platen roller and failure of superimposition with paper. Since the tension between the recording unit and the roller can be kept constant, it is possible to prevent the recorded image from expanding and contracting in the sub-scanning direction. Also, since a torque limiter is provided on one of the pair of rollers, unlike a case where a torque limiter is provided on a supply member or a winding member, regardless of the use condition of the ink ribbon,
The ink ribbon can be conveyed in a state where a certain tension is applied. Further, the recording section conveys between a platen roller rotating at a constant speed and a thermal head resiliently provided on the platen roller, so that a recording sheet with good image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of an image recording apparatus.

FIG. 2 is an explanatory diagram of components arranged on a movement path of an ink ribbon.

[Explanation of symbols]

1 image recording device, 2 body frame, 3
Cover, 4 inner frames, 5 recording section, 6
Recording head, 7 spring, 8 platen roller, 10 ink ribbon, 11 supply unit, 1
2 roll holder, 13 gears, 14 torque limiter, 15 winding unit, 16 roll holder, 17 gears, 18 drive gear, 20 transport roller device, 21 and 22 rollers, 23 torque limiter, 25 paper transport path, 26 separation unit,
27 Discharge roller device.

Claims (3)

[Claims] 1. A supply member that supplies an ink ribbon, a take-up member that takes up the ink ribbon, and a recording unit that is disposed between the supply member and the take-up member and that transfers the ink ribbon to a sheet. An ink ribbon tension mechanism, comprising a pair of rollers for transporting an ink ribbon between the supply member and a recording unit. 2. The ink ribbon tension mechanism according to claim 1, wherein a torque limiter is provided on one of the pair of rollers. 3. The recording section includes a platen roller that rotates at a constant speed, and a thermal head resiliently provided on the platen roller, and a nip between the thermal head and the platen roller. 3. The ink ribbon tension mechanism according to claim 1, wherein the ink ribbon is transported in a state where the ink ribbon is moved.