JPH04120047U - color printer - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent pressing scratches from occurring on the capstan roller. [Structure] Pressure adjusting means (arm 4, fulcrum shaft 3, connecting rod 5, torsion spring 11, drive shaft 6, Pulleys 7, 9, timing belt 1
0, a motor 8, a rotation angle sensor 12, etc.). The capstan roller 2 has a large number of fine protrusions on its outer peripheral surface to prevent slipping. The rotation angle of the drive shaft 6 is adjusted according to the material of the paper, the repulsive force of the torsion spring 11 is adjusted, and the pressing pressure P of the capstan roller 2 against the pinch roller 1 is adjusted. Even with soft paper such as OHP paper, it is possible to prevent pressure scratches from occurring by weakening the capstan roller pressure P.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea involves pinching the paper between a capstan roller and a pinch roller and transporting it back and forth multiple times. The present invention relates to a color printer that prints multiple colors in a sequential manner.

0002

[Conventional technology]

Conventionally, thermal transfer color printers have been able to print colors such as yellow (Y) and magenta. A color image is formed by overlapping three colors: (M) and cyan (C). above The three colors are transferred to the paper in sequential order, so the paper passes over the thermal head three times. must be restored. This back-and-forth conveyance of paper is usually carried out using capstan rollers and pins. However, to avoid color misalignment during surface-sequential transfer, use a capsta roller. For example, a large number of minute thorn-like protrusions with a height of several tens of microns are formed on the outer peripheral surface of the roller. It is common practice to form a paper sheet to transport paper with high precision without slipping. this In some cases, capstan rollers and pinch rollers are used to convey paper without slipping. It is necessary to hold the paper at a pressure above a certain level, but in the past, it was simply a pressure that was considered appropriate. The pressure can be adjusted according to the material of the paper. It wasn't done that way.

0003

[Problem that the idea aims to solve]

As mentioned above, the outer circumferential surface of the capstan roller is coated with fine polyurethane to prevent the paper from slipping. Provides several protrusions and maintains constant pressure between the capstan roller and pinch roller. With conventional color printers that set values, there is no particular problem when using standard paper, but OHP paper (transparent resin sheet used for projection documents of overhead projectors) When printing in color on paper, the surface of the soft OHP paper, which is a resin sheet, is Pressure scratches are caused by the minute protrusions shown below, and these pressure scratches cause OHP paper to be printed. There was a problem in that when the image was placed on a projector, a shadow appeared on the image.

0004 This invention was made to eliminate the above-mentioned conventional drawbacks, and it is similar to OHP paper. Even paper made of soft materials will not be damaged by pressure from capstan rollers, etc. The purpose is to provide a color printer.

[0005]

[Means to solve the problem]

This invention, which solves the above problems, uses a capstan roller and a pinch roller to handle paper. Used in color printers that print multiple colors side by side by conveying the pinch multiple times back and forth. Pressing pressure between the capstan roller and pinch roller depending on the paper material It is characterized by comprising a pressure adjustment means for adjusting the pressure.

[0006]

[Effect]

In the above configuration, when using soft paper such as OHP paper, pressure adjustment is required. By means of weakening the pressing pressure between the capstan roller and the pinch roller . As a result, for example, the outer circumferential surface of a capstan roller has a large number of microscopic parts to prevent slipping. Even if fine protrusions are formed, the paper may be scratched by pressure from capstan rollers, etc. This can be prevented. Note that paper made of soft material has some elasticity and the surface of the roller Since it is in close contact with the roller, the pinching pressure between the capstan roller and the pinch roller is small. There is little risk of slipping even if the capstan roller and pinch roller are used. Highly accurate paper transport is possible.

[0007]

【Example】

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. Figure 1 shows paper being moved back and forth. Paper transport in a full-color printer that performs color printing using thermal transfer in a field-sequential manner. A perspective view of the mechanism section, and FIG. 2 is a side view of the same. The pinch roller 1 is made of rubber, for example. The diameter is the same over the entire length in the paper width direction. The axial center of the pinch roller 1 is fixed. The capstan roller 2 is divided and fixed at multiple locations on the shaft 2a, and the entire outer circumferential surface of the capstan roller 2 is As shown in the partially enlarged cross-sectional view of Fig. It is provided with a large number of thorn-like protrusions 2b about the size of a cylindrical shape. Capstan roller 2 shaft 2a is rotatably supported on left and right arms 4 that are rotatable around a fixed fulcrum shaft 3. Although not shown in the figure, it is supported by a drive pulley coaxial with the fulcrum shaft 3. It is designed to be rotated to convey paper through a belt or the like.

[0008] The other ends of the left and right arms 4 are integrally connected by a connecting rod 5. This connecting rod 5 A drive shaft 6 is arranged in parallel with has been handed over. This torsion spring 11 moves the arm 4 clockwise (arrow) in FIG. It is attached so that a repulsive force is generated that urges it in the direction indicated by mark a. In addition, the drive shaft A pulley 7 is fixed to one end of 6, and a pulley 9 is fixed to the output shaft of a DC motor 8. A timing belt 10 is wound around the pulley 7. The other end of the drive shaft 6 is provided with a rotation angle sensor 12 that detects the rotation angle of the drive shaft 6. this The rotation angle sensor 12 is a so-called rotary encoder, and is fixed to the drive shaft 6. A disc 13 having a notch on its periphery, and a light emitting part 14a sandwiching the periphery of the disc 13. It consists of an optical sensor 14 having a light receiving section 14b. The arm 4, the fulcrum shaft 3 , connecting rod 5, torsion spring 11, drive shaft 6, pulleys 7, 9, motor 8, rotation angle sensor The sensor 12 etc. adjusts the pressing pressure of the capstan roller 2 against the pinch roller 1. It constitutes a pressure adjustment means to adjust the pressure.

[0009] As shown in FIGS. 4 and 5, the four corners of the paper 15 are used to identify the material of the paper 15. Identification marks 16 and 17 corresponding to the material are attached by printing or the like. In the illustrated example is one black line (code 16) for standard paper (Figure 4), and one black line (code 16) for OHP paper (Figure 5). In this case, there are two black lines (symbol 17). Identification marks 16 and 17 in the illustrated example are used for It also serves as a cue mark on the paper.

0010 Next, the operation will be explained. The arm 4 moves as shown in Fig. 2 due to the repulsive force of the torsion spring 11. The caps are biased clockwise (in the direction of arrow a) and supported by the other end of arm 4. The tongue roller 2 presses against the pinch roller 1 with a pressure P corresponding to the repulsive force of the torsion spring 11. It is attached. In this case, depending on the rotation angle (angular position) of the drive shaft 6, the torsion spring The torsional displacement of the torsion spring 11 changes, the magnitude of the repulsive force of the torsion spring 11 changes, and the cap The pressing pressure P of the stun roller 2 against the pinch roller 1 changes.

[0011] Now, suppose you change the paper you are printing on from standard paper to OHP paper or vice versa. , when the paper set in the printer is fed into the paper transport mechanism, an identification (not shown) occurs. Another mark detection sensor detects the identification mark 16 or 17 on the paper and locates the beginning of the paper. At the same time, the type of identification marks 16 and 17 is detected to identify the material of the paper, The motor 8 is automatically operated. When motor 8 operates, pulley 9, timing A drive shaft 6 is rotationally driven via a belt 10 and a pulley 7. In this case, the rotation angle The sensor 12 detects the rotation angle of the drive shaft 6 and feeds it back to the motor 8 to drive the motor. The rotation angle of the shaft 6 is adjusted to a predetermined angle depending on the material of the paper, and thereby the torsion spring Adjust the strength of the repulsion force in step 11 and press the capstan roller 2 against the pinch roller 1. Adjust the application pressure (capstan roller pressure) P.

0012 The adjustment of the capstan roller pressure P described above is for soft paper such as OHP paper. Make it weaker for paper and stronger for standard paper. This allows the capstan row Even if minute protrusions 2b are formed on the outer circumferential surface of the roller 2, It is possible to prevent the paper from being scratched by the pressure of the capstan roller 2. Also, standard If the paper is made of a hard material like paper, there will be no problem with pressure scratches, so the cap The stun roller pressure is sufficiently strong to prevent paper from slipping and achieve high-precision paper transport. do. Note that paper made of soft material has some elasticity and adheres well to the roller surface. Therefore, even if the capstan roller pressure is small, it will grip the paper firmly and cause slippage. There is little risk of Paper transport is possible.

[0013] Note that the paper material identification mark also serves as the paper cue mark, as shown in the example. It is also possible to use a dedicated mark instead. Also, as in the example, feed the paper In addition to the configuration that automatically detects the material and adjusts the pressure when inserting the material, for example, switching A switch or adjustment dial may be installed to manually adjust the pressure. It is possible. In addition, fine protrusions are provided on the pinch roller 1 side to prevent slipping. It is also possible.

[0014]

[Effect of the idea]

According to the present invention, the capstan roller and the pinch roller can be used depending on the paper material. A pressure adjustment means is provided to adjust the pressing pressure between the Even in the case of soft materials, fine protrusions are provided on the outer circumferential surface of the capstan roller etc. to increase the height. Achieves accurate conveyance function, but at the same time prevents pressure scratches from capstan rollers, etc. It is now possible to prevent this.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of a color printer of the present invention, and is a perspective view of a paper conveyance mechanism.

FIG. 2 is a side view of the paper conveyance mechanism section in FIG. 1;

FIG. 3 is a partially enlarged sectional view of the capstan roller.

FIG. 4 is an explanatory diagram of marks for material identification on standard paper.

FIG. 5 is an explanatory diagram of marks provided on OHP paper for material identification.

[Explanation of symbols]

1 Pinch roller 2 Capstan roller 3 Fulcrum shaft 4 Arm 5 Connecting rod 6 Drive shaft 8 motor 11 Torsion spring 12 Rotation angle sensor

──────────────────────────────────────────────── ─── Continued from front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B41J 11/42 Z 9011-2C 13/00 8603-2C

Claims (1)

[Scope of utility model registration request] 1. In a color printer that prints multiple colors in a field-sequential manner by sandwiching a sheet of paper between a capstan roller and a pinch roller and conveying it back and forth multiple times, there is a difference between the capstan roller and the pinch roller depending on the material of the sheet. A color printer characterized by comprising a pressure adjustment means for adjusting the pressing pressure of the color printer.