JPS60236779A - Feeder for thin sheet form material - Google Patents

Abstract

PURPOSE:To accurately control the feeding velocity of an ink doner film or a recording paper and prevent misregister of colors from occurring, by providing a roller having multiple projections on the outer periphery thereof and being rotated in contact with the ink doner film or the recording paper and a means for detecting the rotating speed of the roller. CONSTITUTION:Recording in different colors is conducted by multiple stages of devices for recording while passing ink doner films 2, 12 and a recording paper 21 in a laminated condition between a recording heads 5, 15 and a platen rollers 6, 16. In this case, to accurately control the feeding velocities of the films 2, 12 and the paper 21 in each of the recording devices, rollers 8, 18 and the rotating speed detecting means are provided. The rollers 8, 18 are provided with minute projections on the outer periphery thereof, and is rotated while maintaining the projections in contact with the films 2, 12 or the paper 21. The rotating speed detecting means is constituted by, for example, fitting circular disks 33, 34 to the shafts 31, 32 of the rollers 8, 18, providing the disk 33 with a multiplicity of slits 35, 36 and providing light-emitting elements 39, 40 and light-receiving elements 37, 38 on opposite sides of the disks 33, 34.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a device for conveying a thin plate-like material made of an ink donor film or recording paper in a transfer type thermal recording device.

``Prior art'' In a transfer-type thermal recording bag device, an ink donor film coated with ink on one side of the base paper is placed on top of the recording paper, and in this state, a thermal head selectively prints the ink from the base paper side of the ink donor film. It's heating up.

The ink fluidized or sublimated by this heating is transferred to recording paper, and image information is recorded. Therefore, if the colors of ink are different, it is possible to perform multicolor recording.

FIG. 1 shows an example of a conventional transfer type thermal recording apparatus capable of recording in two colors, for example, black and red.

This recording apparatus is provided with a black recording section 1 at the front stage and a red recording section 11 at the rear stage. The black recording section 1 is equipped with a long ink donor film 2 coated with black ink and wound around a supply roll 3. The ink donor film 2 fed out from the supply roll 3 passes through a guide roller 4, between a thermal head 5 and a back roller 6, and between a drive roller 7 and a pinch roller 8, and then is wound onto a take-up roll 9. It is now possible to

The red recording section 11 is equipped with a long ink donor film 12 coated with red ink wound around a supply roll 13 . In this red recording section 11 as well, the ink donor film 12 fed out from the supply roll 13 passes through the guide roller 14, between the thermal head 15 and back roller 16, and between the drive roller 17 and pinch roller 18, and then is wound. It is adapted to be wound up on a take-up roll 19.

When a recording paper 21 is sent out from a paper feed tray (not shown) of this recording apparatus, it is overlapped with a black ink donor film 2 in front of the thermal head 5 . When the drive roller 7 rotates at a predetermined timing and conveyance of the ink donor film 2 is started, the recording paper 21 passes between the thermal head 5 and the back roller 6 while being overlapped with the ink donor film 2. At this time, the thermal head 5 is driven and recording in black is performed.

The recording paper 21 after the black recording is completed is the ink donor film 2.
The ink donor film 12 is peeled off from the ink donor film 12 and guided by the paper guide 22 into the red recording section 11, where it is overlapped with the red ink donor film 12 in front of the thermal head 15. When conveyance of the ink donor film 12 is started at a predetermined timing, red recording is performed using the same recording principle as black recording. After two-color recording, the recording paper 21 is peeled off from the ink donor film 12, conveyed in the direction of the arrow, and discharged to a discharge tray (not shown).

By the way, in such a recording apparatus, the drive roller 7.
If there are variations in dimensional accuracy or assembly accuracy in the driving force transmission system for rotating the image forming apparatus 17, the image quality will be inferior. That is, if there are variations in the dimensional accuracy of the elements, the conveyance speed of the recording paper 21 in each recording section 1.11 will differ from each other. If the conveyance speeds are different from each other, color misalignment will occur,
The image quality will be inferior.

Therefore, in such a recording apparatus, each conveying speed of the ink donor film 2.12 is detected by detecting each rotation amount of the drive roller 7.17 that contacts it with a row reencoder or the like, and each result is Based on this, the conveyance speed of the ink donor film 2.12 and the recording paper 21 superimposed thereon in each recording section 1.11 is controlled during each recording, thereby reducing color shift.

However, in such a recording device, the ink donor film 2.12 is transported by the frictional force of the rubber drive roller 7.17, so if the surface becomes dirty or deteriorates over time, it may slip locally. sometimes occurred. If slippage occurs, the drive roller 7.1
The rotation amount of the ink donor film 7 and the transport speed of the ink donor film 2.12 are no longer proportional, resulting in a detection error and, as a result, it becomes impossible to sufficiently reduce color shift.

[Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, and it is a method to solve the following problems: It is an object of the present invention to provide a thin plate material conveying device that can always and reliably make the conveyance speed of the thin plate material proportional to the conveyance speed of the thin plate material.

"Means for Solving the Problems" In the present invention, a roller for contacting a thin plate-like material such as an ink donor film and detecting its conveyance speed is configured to have minute protrusions on one circumference. This makes it difficult for slips to occur between the two.

"Example" The present invention will be described in detail below with reference to Examples.

FIG. 2 shows the main parts of a transfer type thermal recording apparatus to which an embodiment of the present invention is applied, and FIG. 3 shows a part thereof. In these figures, parts with the same names as those in FIG.

In this recording apparatus, the conveying speed of the ink donor film 2.12 is detected by detecting the amount of rotation of the pinch roller 8.18. For this purpose, disks 33, 34 for detecting the amount of rotation are attached to the shafts 31, 32 of the pinch rollers 8, 18, respectively.

A plurality of slits 35, 36 are formed in the disc 33, 34 at equal intervals in the circumferential direction. On both sides of the disk 33, 34 are light emitting elements 37, 38 and light receiving elements 39, 40.
are placed respectively.

The pinch roller 8.18 has minute protrusions 41.4 on the outer periphery.
It has a structure with 2. The fine protrusions 41 and 42 are file-like protrusions formed by thermal spraying the surface of a metal roller, or file-like protrusions formed by attaching granular materials of about 30 to 300 μm, and It consists of a cross-grain or flat-grain low left. On the other hand, the drive roller 7.17 has a structure in which a rubber layer is provided on the outer periphery of a metal shaft. The pinch rollers 8.18 are pressed against the drive rollers 7.17 with appropriate pressing forces by springs or the like (not shown).

In this recording apparatus, a recording paper 21 fed from a paper feed tray (not shown) is first fed into a black recording section 1 where black recording is performed, and then fed into a red recording section 11 where red recording is performed. This is the same as in the conventional example described above.

When recording is performed in the black recording section 1 of this recording device,
The rotation of the drive roller 7 causes the ink donor film 2 to
is conveyed together with the recording paper 21 superimposed thereon.

At this time, the pinch roller 8 is rotated while reliably following the conveyance of the ink donor film 2 because its protrusion 41 has bitten into the ink donor film 2 appropriately. The amount of rotation of the pinch roller 8 is detected when the slit 35 of the disk 33 rotated together with the pinch roller 8 passes between the light emitting element 39 and the light receiving element 41. That is, the light receiving element 41 sequentially detects the slits 35 formed at regular intervals on the disk 33.

The detection signal output from the light receiving element 41 is supplied to a conveyance amount detection circuit 51 shown in FIG. Conveyance amount detection circuit 51
calculates the conveyance speed of the ink donor film 2 based on the detection signal from the light receiving element 41. This calculation result is supplied to the arithmetic circuit 52. The calculation circuit 52 compares the calculation result from the conveyance amount detection circuit 51 and the reference signal from the reference signal generation circuit 53, and controls the motor drive circuit 54 based on the comparison result. As a result, the frequency applied to the step motor 55 for rotating the drive roller 7 is controlled. That is, when the conveyance speed of the ink donor film 2 is the expected speed, the step motor 55 is driven as expected, and the drive roller 7 is driven as expected.
is rotated at the desired rotation speed. If the conveying speed of the ink donor film 2 is slower than the expected speed, the step motor 55 is driven faster and the drive roller 7 is rotated at a faster speed than the expected speed, and if it is faster, then the drive roller 7 is rotated at a slower speed. It will be rotated by

On the other hand, in the red recording section 11, similarly to the black recording section 1,
Since the projections 42 of the pinch roller 18 suitably bite into the ink donor film 12, the pinch roller 18 is rotated while reliably following the conveyance of the ink donor film 12. Further, the rotational speed of the drive roller 7 is controlled using the same control principle as that of the black recording section 1. In other words, even in the red recording section 11,
The detection signal from the light receiving element 40 is supplied to the conveyance amount detection circuit 61, the calculation result from the conveyance amount detection circuit 61 is supplied to the calculation circuit 62, and the motor drive circuit 64 is controlled based on the comparison result of the calculation circuit 62. This □ controls the frequency applied to the step motor 65 for rotating the drive roller 17.

In this manner, in this recording apparatus, the projections 41.42 of the pinch roller 8.18 bite into the ink donor film 2.12 appropriately, so that no slip occurs between them. Therefore, it is ensured that the respective transport speeds of the ink donor film 2.12 and the respective rotation amounts of the pinch rollers 8.18 for detecting these transport speeds are always reliably proportional. For this reason, the conveyance speeds of both ink donor films 2.12 are always controlled to be the desired conveyance speed,
The conveyance speed of the recording paper 21 in each recording section 1.11 is the expected conveyance speed.

In the above embodiment, the pinch roller 8.18 is provided with the protrusion 4I,
Although the roller 42 is a tri-blow rough and the rubber roller 17 is a rubber roller, the reverse may be used. In this case, the amount of rotation of the drive roller 7.17 having a protrusion is detected. Alternatively, the guide roller 4.14 may be a roller having a protrusion, and the amount of rotation of the roller may be detected to control the amount of rotation of the drive roller 7.17.

Further, in the above embodiment, each recording section 1.11 independently controls the transport speed of the ink donor film 2.12, but the black recording section 1 does not control the conveyance speed of the ink donor film 2.12. Control may be performed only by the red recording unit 11 based on the transport speed of . Further, in the above embodiment, the drive rollers 7.17 are rotated by dedicated step motors 55.65, but they may be rotated by a common step motor.

Furthermore, although the above embodiment describes the case where two colors, black and red, are recorded using two recording units, it is of course applicable to cases where three or more colors are recorded using three or more recording units. be. It is also naturally applicable to the case where one of the two recording sections is provided with a relatively thin black ink donor film, and the other is provided with a relatively dark black ink donor film, thereby performing gradation recording. Naturally, the present invention can also be applied to single-color recording or multi-color recording in a single recording section. When recording a single color using a single recording section, the recording pitch in the sub-scanning direction is constant, and the reduction ratio can be kept constant. When performing multicolor recording on a single recording section, use an ink donor film in which multiple colors of ink are sequentially applied in the length direction of the base paper on one side of the base paper in a size that corresponds to the recording paper. The recording paper that has passed through the thermal head may be returned to the front side of the thermal head several times.

Furthermore, in the above embodiment, the transport speed of the ink donor film 2.12 is detected, but a roller having a protrusion is arranged in each recording section 1.11 so as to be in direct contact with the recording paper 21. Dry Pro by directly detecting the conveyance speed of
(7.17) The amount of rotation may be controlled.

"Effects of the Invention" As explained above, according to the present invention, the conveyance speed of a thin plate-like material such as an ink donor film can be detected reliably, so that the conveyance speed can be well controlled. Therefore, in the case of multi-color recording, for example, displacement of the recording surface during each recording process can be reduced as much as possible, improving image quality.

Furthermore, in the case of single-color recording, the recording pitch in the sub-scanning direction can be kept constant, the reduction ratio can be kept constant, and the image quality can be improved.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an example of a conventional transfer type thermal recording device capable of performing two-color recording, and Fig. 2 is a schematic diagram showing an example of a conventional transfer type thermal recording device capable of performing two-color recording. FIG. 3 is a perspective view showing a part of the apparatus, and FIG. 4 is a block diagram showing the main parts of the electric circuit of the apparatus. 2.12...Ink donor film, 3.13
...... Supply roll, 4.14... Guide roller, 5.15... Thermal head, 6.16...
...Back roller, 7.17...Drive roller, 8.18...
... Pinch roller, 9.19 ... Take-up roll, 21 ... Recording paper, 22 ... Paper guide, 33.34 ... Disc plate , 35, 36... Slit, 37.38... Light emitting element, 39.40... Light receiving element, 41.42... protrusion. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Umeo Yamauchi Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] In a transfer-type thermal recording device that records image information by conveying an ink donor film together with a recording paper superimposed on the ink donor film and selectively heating the ink donor film with a thermal head at this time, fine protrusions on the outer peripheral portion 55 are formed. a roller that is rotated in contact with a thin plate-shaped material made of an ink donor film or recording paper; a detection means for detecting the rotation angle of this roller per a certain period of time; 1. A thin plate material conveying device, comprising: a control means for controlling the amount of rotation of a drive roller for conveying a thin plate material.