JP2007284199A - Thermal printer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveying mechanism capable of obtaining grip force required for respective recording papers and suppressing the generation of color ununiformness by high conveying accuracy. <P>SOLUTION: In the thermal printer using a plurality of kinds of recording papers, a plurality of original projections are provided on a capstan roller and a switching mechanism of an abutment position of a pinch roller and the capstan roller is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal printer device, and more particularly to a mechanism for conveying recording paper in a thermal printer device.

  FIG. 10 is a schematic configuration diagram showing a transport mechanism of a thermal printer apparatus that has been generally used conventionally. In the figure, an ink ribbon 13 is sent from a feed roll 13a to a take-up roll 13b through a thermal head 11, and the thermal ribbon 11 presses against the platen roller 12 to apply heat, whereby the ink ribbon 13 The dye applied to is transferred onto the recording paper 14. The recording paper 14 is nipped between the pinch roller 1 and the capstan roller 2 at a predetermined pressure, and the capstan roller 2 is conveyed counterclockwise by rotating counterclockwise.

  When the conveyance accuracy of the recording paper 14 by the pinch roller 1 and the capstan roller 2 is not good, when color recording is performed in the surface sequential manner, the position where the dye is transferred is shifted on each surface, and the output is blurred (color Misalignment) may occur. As a countermeasure against such color misregistration, for example, the capstan roller 2 is provided with Mt. Fuji type protrusions and 1/4 spherical protrusions at a predetermined height (60 ± 40 μm) and a predetermined interval (0.5 ± 0.2 mm). Therefore, there has already been proposed one that increases the gripping force to increase the conveyance accuracy (see, for example, Patent Document 1).

JP-A-11-240654 (page 4, FIG. 14)

However, the protrusion height and interval of the capstan roller that can provide the necessary gripping force differ depending on the type of recording paper, so when using multiple types of recording paper with the same capstan roller, There is a problem that it is difficult to obtain the optimum conveyance accuracy.
The gripping force depends on the pressing force of the pinch roller. Increasing the pressing force increases the gripping force of each recording paper. However, depending on the type of recording paper, the pinch roller indentation and capstan roller There is also a problem that the traces of the protrusions become conspicuous and the print quality is deteriorated. The present invention has been made in view of the above problems, and even when a plurality of types of recording paper is used, a necessary grip force can be obtained for each recording paper, and occurrence of color misregistration can be suppressed with high conveyance accuracy. An object of the present invention is to provide a transport mechanism that can handle the above-described problem.

  The present invention is a thermal printer apparatus using a plurality of types of recording paper, wherein a plurality of projections are provided on the capstan roller, and a mechanism for switching a contact position between the pinch roller and the capstan roller is provided. .

As described above, by providing a plurality of projections on the capstan roller and providing a mechanism for switching the abutment position between the pinch roller and the capstan roller, a printer that uses a plurality of types of recording paper can perform each recording. A thermal printer apparatus that can obtain an optimum grip force for paper and can suppress occurrence of color misregistration with high conveyance accuracy is obtained.
In addition, by providing a pressing force switching mechanism that switches the pressing force depending on the type of recording paper, it is possible to prevent a decrease in print quality due to a pinch roller impression or a capstan roller protrusion.

Embodiment 1 FIG.
A thermal printer apparatus according to Embodiment 1 of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a paper transport mechanism of a thermal printer apparatus, which is substantially the same as that shown in FIG. FIG. 2 is a block diagram showing the principal part of the thermal printer apparatus according to Embodiment 1 of the present invention, and the same reference numerals are assigned to the parts corresponding to those in FIG. In the figure, the pinch roller 1 faces the capstan roller 2, and the pinch roller 1 is supported by a support arm 4. Note that the position of the pressure arm 5 changes as the cam 3 rotates.

  An elastic body 6 such as a spring is connected between the support arm 4 and the pressure arm 5, and the relative position of the support arm 4 and the pressure arm 5 changes as the cam 3 rotates. FIG. 3 is a table (cam chart) showing the relative positions of the support arm 4 and the pressure arm 5, and FIG. 4 is a diagram showing the positional relation of each component when the cam 3 rotates. As is apparent with reference to both drawings, the pinch roller 1 is separated from the capstan roller 2 in the P1 position. At the P2 position, the pinch roller 1 comes into contact with the capstan roller 2, and the elastic body 6 is pulled by the pressure arm 5 to generate a pressing force Pa. At the P3 position, the pressing arm 5 pulls the elastic body 6 more strongly than the P2 position, so that the pressing force Pb is larger than Pa.

  FIG. 5 is an enlarged configuration diagram of the pinch roller 1 shown in FIG. 1, and the pinch roller 1 includes a shaft 6, rollers 7a and 7b, and fastening parts 8a and 8b. The shaft 6 has four steps (6a, 6b, 6c, 6d). The rollers 7a, 7b penetrating the shaft 6 are fastened at the stepped portions by the fastening parts 8a, 8b to thereby fix the rollers 7a, 7b. It can be detachably fixed to the shaft 6.

  FIG. 6 is a view showing a protrusion arrangement state of the capstan roller 2 shown in FIG. 1, and the protrusions 9 a and 9 b configured with predetermined specifications are arranged at positions facing the steps 6 a and 6 d of the pinch roller 1. Yes. Further, the protrusions 10 a and 10 b configured with different specifications are arranged at positions facing the steps 6 b and 6 c of the pinch roller 1. FIG. 7 is a diagram showing an example of the specific shape of the protrusions in FIG. The mountain-shaped protrusion as shown in FIG. 7 is manufactured by winding or welding or bonding a plate on which a protrusion is formed by a manufacturing method such as etching around a shaft.

  FIG. 8 is a diagram showing a configuration example of different types of recording papers 14 and 15 used in the thermal printer. The recording paper 14 includes an image receiving layer 14a to which a dye is transferred, a base material 14b made of natural paper, and a back layer 14c made of resin. The back surface layer 14c has a role of reducing curl in the roll paper by sandwiching the base material 14b with the image receiving layer 14a between the front and back surfaces. On the other hand, the recording paper 15 includes an image receiving layer 15a to which a dye is transferred and a base material 15b made of natural paper. Since there is no back layer 14c, it is advantageous in terms of cost, but it is easy to cause curling, and the recording paper 15 is likely to have a pinch roller indentation or capstan roller protrusion trace with a lower pressing force than the recording paper 14.

FIG. 9 is a graph showing the grip force F obtained when the gap L and the pressing force P of the capstan roller 2 are changed for the above-mentioned different types of recording papers 14 and 15. The horizontal line Fr at the center indicates the level of grip force required to obtain proper conveyance accuracy.
FIG. 9 illustrates a case where the protrusions of the capstan roller 2 are changed into two types of intervals L = 0.26 mm and L = 0.4 mm. First, when the recording paper 14 is used at an interval L = 0.26 mm, the gripping force F increases as the pressing force P increases as shown by the line P14a, so that an appropriate conveyance accuracy can be obtained with the pressing force Pb. The necessary grip force can be obtained.

  However, when L = 0.4 mm, the grip force F is saturated with respect to the pressing force P as shown by the line P14b. On the other hand, in the case of the recording paper 15, the grip force F increases with respect to the pressing force P in both cases of L = 0.26 mm (see the line P15a) and 0.4 mm (see the line P15b), but L = 0.4 mm. The grip force F is higher in (P15b), and the necessary grip force can be obtained with a pressing force Pa lower than that of the recording paper 14. When the recording paper 15 is pressed with the pressing force Pb, the indentation of the pinch roller 1 and the protrusion mark of the capstan roller 2 are conspicuous, and the printing quality is deteriorated. Therefore, the pressing force of the recording paper 15 needs to be set lower than Pb. Note that the graphs of FIGS. 9A and 9B are examples in each case where the projection height H = 60 ± 10 μm and the projection tip diameter R = 35 ± 5 μm.

  As described above, the protrusions 9a and 9b of the capstan roller 2 are L = 0.26 mm, H = 60 ± 10 μm, R = 35 ± 5 μm, the protrusions 10a and 10b are L = 0.40 mm, H = 60 ± 10 μm, R = If the recording paper 14 is used, an appropriate grip force can be obtained by fixing the rollers 7a and 7b of the pinch roller 1 at the positions of the steps 6a and 6d and pressing them with the pressing force Pb. When the recording paper 15 is used, an appropriate grip force can be obtained by fixing the rollers 7a and 7b at the positions of the steps 6b and 6c and pressing with a pressing force Pa lower than Pb. It has been found that it does not occur.

  Hereinafter, the printing operation of the recording sheets 14 and 15 will be described with reference to FIGS. In the schematic configuration diagram of FIG. 1, the thermal head 11 faces the platen roller 12, and the dye applied to the ink ribbon 13 is transferred to the recording papers 14 and 15 by applying heat to the ink ribbon 13. As described above, the recording sheets 14 and 15 are sandwiched between the pinch roller 1 and the capstan roller 2 with a predetermined pressure and conveyed from the right to the left by the rotation of the capstan roller 2.

  First, the printing operation when the recording paper 14 is used will be described with reference to FIGS. When the recording paper 14 is not present, the P1 position (FIG. 3) is set, and the protrusion of the capstan roller 2 is prevented from being damaged by separating the pinch roller 1 and the capstan roller 2, and the recording paper 14 is easily received. . In this state, the rollers 7a and 7b are fixed at the positions of the steps 6a and 6d. When printing is started, the P3 position is reached, and the recording paper 14 is clamped between the projections 9a and 9b of the pinch roller 1 and the capstan roller 2 with pressure Pb, and the thermal head 11 moves to a position where it presses against the platen roller 12 and the ink ribbon. 13 and the recording paper 14 start the conveying operation.

  A predetermined amount of heat corresponding to the print data is applied from the thermal head 11 to the ink sheet 13, and the dye applied on the ink sheet 13 is transferred to the recording paper 14 line by line. After sending a predetermined line, the thermal head 11 moves to a position away from the platen roller 12, the recording paper 14 is rewound to the printing start position, and the ink sheet 13 is taken up to the next screen. In the frame sequential thermal transfer printer, the above operation is repeated for three colors YMC to form an image.

  Next, the printing operation when the recording paper 15 is used will be described in the same manner. When there is no recording paper 15, the P1 position is set. In this state, the rollers 7a and 7b are fixed at the positions of the steps 6b and 6c. When printing is started, the P2 position is reached, and the recording paper 15 is clamped between the projections 10a and 10b of the pinch roller 1 and the capstan roller 2 with pressure Pa, and the thermal head 11 moves to a position where it comes into pressure contact with the platen roller 12 and the ink ribbon 13 And the recording paper 15 starts the conveying operation. Thereafter, the same operation as that in the case of using the recording paper 14 described above is performed, and thus the description thereof is omitted.

  As a method for identifying the recording paper 14 and the recording paper 15, a manual identification method such as selection on a printer driver or an automatic identification method such as reading with a non-contact or contact IC tag attached to the core of the recording paper can be considered. . As a pressing force switching mechanism for switching the pressing force depending on the type of recording paper, the cam 3 or an auxiliary plate that rotates in synchronization with the cam 3 is provided with an arbitrary protrusion or reflecting portion. A method of detecting this with a sensor is conceivable.

  Moreover, although the case where the protrusion interval L is changed to two types of 0.26 mm and 0.40 mm as the protrusions of a plurality of specifications has been shown, the present invention is not limited to this, and other protrusions such as 0.30 mm, for example. It is also applicable to the interval. The higher the protrusion height H, the higher the conveyance accuracy, but there is a tendency to saturate at a certain height or more, and the protrusion tip diameter R generally increases the conveyance accuracy when the protrusion is thin. Since there is a tendency to bend, it is used in the setting range of the above embodiment.

  Further, in the above embodiment, when the recording paper 14 is used, the case where the portion of the pinch roller that contacts the capstan roller and the pressing force of the portion are simultaneously switched has been described. It is also possible to realize the above-mentioned without changing the pressing force switching mechanism by optimally setting the projection interval and height.

1 is a configuration diagram of a main part of a thermal printer apparatus showing Embodiment 1 of the present invention. 1 is a configuration diagram of a thermal printer apparatus showing Embodiment 1 of the present invention. Position change table of holding arm and pressure arm Position change diagram of holding arm and pressure arm Configuration diagram of pinch roller Capstan roller projection layout Specific shape of capstan roller protrusion Configuration example of recording paper Graph showing the grip strength characteristics of recording paper Configuration diagram of a conventional thermal printer device

Explanation of symbols

1 Pinch roller,
2 Capstan roller,
3 cams,
4 holding arm,
5 Pressure arm,
6 Pinch roller shaft,
6a, 6b, 6c, 6d Shaft step,
7a, 7b roller,
8a, 8b fastening parts,
9a, 9b Protrusion of capstan roller,
10a, 10b Capstan roller protrusion,
11 Thermal head,
12 Platen roller,
13 Ink ribbon,
14 Recording paper with back layer,
14a image receiving layer,
14b base material,
14c back layer,
15 Recording paper without back layer,
15a image receiving layer,
15b Substrate.

Claims (5)

  In a thermal printer that transports recording paper by a capstan roller and a pinch roller that is in pressure contact with the capstan roller, the capstan roller is provided with a plurality of projections having different specifications, and is in contact with the capstan roller of the pinch roller. A thermal printer device characterized in that the contacting portion is variable between the projections of the plurality of specifications according to the specifications of the recording paper.   2. The thermal printer apparatus according to claim 1, wherein the pressing force of the pinch roller can be switched to a plurality of specifications according to the specifications of the recording paper.   2. The thermal printer apparatus according to claim 1, wherein the capstan roller has a protrusion interval in the case of using a recording paper having a two-layer structure without a back layer than when using a recording paper having a back layer. A thermal printer device characterized by being wider.   3. The thermal printer apparatus according to claim 2, wherein the pressing force of the pinch roller uses a recording paper having a two-layer structure without a back layer than using a recording paper having a three-layer structure with a back layer. A thermal printer device characterized by low.   3. The thermal printer apparatus according to claim 2, wherein when the recording paper having the first specification is used, a portion of the pinch roller that contacts the capstan roller is a projection portion having a first specification. When setting the pressing force and using the recording paper of the second specification, the portion that contacts the capstan roller of the pinch roller is the projection portion of the second specification, and the second pressing force is set. A thermal printer apparatus characterized by that.

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