JP2001253131A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of accurately printing on a predetermined position even in the case of using a printing paper with high transmissivity. SOLUTION: This printer 10 is provided with a sensor 36. A light beam is directed from a light emitting element 40 to a label paper 18, and the light reflected by the label paper 18 is received by a light receiving element 42. A mark 30 with a reflectance different from that of a base paper 26 is formed in the label paper 18. The position of the mark 30 is sensed, utilizing the difference of the reflectances of the mark 30 and the base paper 26. A reflection plate 38 is disposed facing the sensor 36 so that a light beam transmitted the label paper 18 is reflected by the reflection plate 38 to the light receiving element 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer that detects a mark printed on the back side of a printing sheet and determines a position where printing is started or cut.

[0002]

2. Description of the Related Art A printer that prints on a label temporarily attached to a band-shaped backing paper senses the position of the label by a sensor,
Printing on the label is started based on the detected timing. Examples of the sensor include an optical sensor including a light emitting element and a light receiving element. In this optical sensor, the light emitting element emits light toward the mount, and the light receiving element receives light reflected by the mount. On the mount, at predetermined intervals, a mark having a light reflectance different from that of the mount is printed, and the sensor detects a change in the amount of light between the reflected light reflected by the mark and the reflected light reflected by the mount. To detect the mark. Then, by starting printing based on the timing at which the mark is detected, printing is accurately performed at a predetermined position on the label.

[0003]

However, the conventional printer has a problem that when the mount or label is thin, light from the light emitting element passes through the mount or label and the amount of light reflected from the mount decreases. When the amount of reflected light from the mount decreases, the difference between the amount of reflected light from the mount and the amount of reflected light from the mark decreases, and the sensor cannot detect the mark correctly. For this reason, the conventional printer has a problem that the printing position is shifted from a predetermined position or printing is not performed when the mount sheet or the label is thin.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a printer capable of printing accurately at a predetermined position even when using printing paper having a high light transmittance. Aim.

[0005]

In order to achieve the above object, the present invention provides a light emitting means for emitting light toward a printing paper, and receiving light emitted by the light emitting means and reflected by the printing paper. A printer comprising a sensor for detecting a change in the amount of light received by the light receiving means, wherein the light reflected from the light emitting means and transmitted through the printing paper is reflected toward the light receiving means. Means are provided.

According to the present invention, since the reflection means reflects the light transmitted through the printing paper toward the light receiving means, even when the light transmittance of the printing paper is high, the apparent amount of reflected light from the printing paper is small. growing. Thus, for example, when a mark having a small reflectance is provided on the printing paper, a large difference between the amount of reflected light from the printing paper and the amount of reflected light from the mark is secured, so that the sensor can reliably detect the mark. it can. Therefore, by performing printing based on the timing at which the sensor detects the mark, it is possible to accurately print at a predetermined position on the printing paper.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a printer according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram showing the structure of a printer according to the present embodiment.

As shown in FIG. 1, a thermal head 14 and a platen roller 16 are disposed opposite to each other in a printing unit 12 of a printer 10, and a label paper is placed between the thermal head 14 and the platen roller 16. 18 and the ink ribbon 20 are supplied. The ink ribbon 20 is mounted on the ink ribbon supply reel 22 in a wound state, is rewound from the ink ribbon supply reel 22, and is supplied to the printing unit 12.

On the other hand, the label paper 18 is wound in a roll shape and mounted on a supply reel 24. This label paper 1
8, a plurality of labels 28, 28,... Are temporarily attached at predetermined intervals to the surface of a band-shaped backing sheet 26, as shown in FIG.
Marks (or eye marks) 30, 30 are printed on both sides of a position corresponding to the rear end of each label 28 on the back surface of the backing paper 26. The mark 30 is printed with, for example, a black paint having a low reflectance, and has a significantly different reflectance from the mount 26. As a result, the PCS value (relative reflectance of printing) increases, and the position of the mark 30 can be detected by a change in the amount of reflected light from the label paper 18.

The label paper 18 mounted on the supply reel 24 shown in FIG. 1 is rewound and guided by the guide rollers 32, and then supplied to the printing unit 12. The label paper 18 supplied to the printing unit 12 is printed with a bar code and character information on the label 28 in the printing unit 12, and
4

A sensor 36 is provided between the printing unit 12 and the guide roller 32. The sensor 36 is shown in FIG.
As shown in FIG. 5, the light emitting device 40 includes a light emitting element 40 and a light receiving element 42. The light emitting element 40 emits light toward the back surface of the label paper 18, and the light receiving element 42 receives light reflected by the label paper 18. I do. As the light emitting element 40, for example, an LED is used, and as the light receiving element 42, for example, a photodiode or the like is used. The light emitting element 40 and the light receiving element 42 are arranged symmetrically with respect to an axis perpendicular to the label paper 18 to be transferred, and the light receiving element 42 receives light emitted from the light emitting element 40 and reflected by the label paper 18. . The sensor 36 configured as described above detects the mark 30 based on a change in the amount of light received by the light receiving element 42 by utilizing the difference between the reflectance of the mark 30 and the reflectance of the mount 26. That is, the sensor 36 recognizes the mark 30 when the amount of light received by the light receiving element 42 decreases.
The printing unit 12 starts printing based on the timing at which the sensor 36 detects the mark 30.

On the opposite side of the label paper 18 from the sensor 36, a reflection plate 38 is provided. The reflecting plate 38
The surface on the label paper 18 side is processed so as to be easily reflected, and this surface is arranged parallel to the label paper 18. Accordingly, when the light emitted from the light emitting element 40 of the sensor 36 passes through the label paper 18, the transmitted light is reflected by the reflector 38 toward the light receiving element 42.

Next, the operation of the printer 10 configured as described above will be described with reference to FIGS.

As shown in FIGS. 4A and 4B,
When the mount 26 or the label 28 is sufficiently thick, the light transmitted from the light emitting element 40 hardly passes through the label paper 18 because the light transmittance of the label paper 18 is small. Therefore, as shown in FIG. 4A, when light is projected on the mount 26 having a high reflectance, most of the light is reflected by the mount 26, and thus the amount of light received by the light receiving element 42 is large. FIG.
As shown in (b), when light is projected on the mark 30 having a small reflectance, a part of the light is absorbed by the mark 30, so that the amount of light reflected on the mark 30 is small and the light is received by the light receiving element 42. The amount of light that is emitted Here, assuming that the amount of light reflected by the mount 26 is A1, and the amount of light reflected by the mark 30 is B1, the ratio A1 / B1 is sufficiently large.
Therefore, when the mark 30 passes through the position of the sensor 36, the amount of light received by the light receiving element 42 changes greatly, whereby the mark 30 can be detected.

As shown in FIGS. 5A and 5B,
When the mount 26 and the label 28 are thin, the light transmittance of the label paper 18 increases. Therefore, as shown in FIG. 5A, when light is projected on the mount 26, a part of the light passes through the label paper 18, so that the amount of reflected light A2 directly reflected by the mount 26 decreases. On the other hand, as shown in FIG. 5B, when light is projected on the mark 30, a part of the light is absorbed by the mark 30, so that the reflected light amount B2 is independent of the light transmittance of the label paper 18. , Remains small. Therefore, the reflected light amount A2 of the mount 26 and the reflected light amount B2 of the mark
Is smaller. For this reason, in the conventional device, the fluctuation of the amount of light received by the light receiving element 42 is small, and it has been difficult to accurately detect the mark 30. On the other hand, in the printer 10 of the present embodiment, since the reflection plate 38 is provided, the transmitted light transmitted through the mount 26 is reflected by the reflection plate 38, transmitted through the mount 26, and received by the light receiving element 42. You. Here, assuming that the amount of light reflected by the reflector 38 is A3,
The apparent amount of light reflected by the mount 26 is (A2 + A
3), and the difference from the reflected light amount B2 of the mark 30 increases. That is, the ratio (A2 + A3) / B2 of the amount of reflected light between the mount 26 and the mark 30 increases, so that the sensor 36 can reliably detect the mark 30.

As described above, the printer 10 according to the present embodiment
According to the present invention, since the reflection plate 38 that reflects the transmitted light transmitted through the mount 26 toward the light receiving element 42 is provided, the label paper 1
Even when the light transmittance of No. 8 is high, the mark 30 can be reliably detected. That is, the printer 10 is able to operate the mark 3 without being affected by the light transmittance of the label paper 18.
0 can be reliably detected. Thereby, it is possible to print accurately at a predetermined position of the label 28.

In the above-described embodiment, the reflecting plate 38 may be a means for reflecting the transmitted light transmitted through the label paper 18 to the light receiving element 42, and may be, for example, a prism or the like.

It is also possible to provide a support mechanism for supporting the reflecting plate 38 so as to be able to move forward and backward with respect to the label paper 18 to be transferred, and to move the reflecting plate 38 forward and backward according to the thickness of the label paper 18.

An angle adjusting mechanism for adjusting the angle of the reflecting plate 38 may be provided, and the angle of the reflecting plate 38 may be adjusted so that the light is reflected toward the light receiving element 42 without fail.

In the above-described embodiment, the sensor 36
Started printing based on the timing at which the mark 30 was detected, but the invention is not limited to this. For example, based on the timing at which the sensor 36 detects the mark 30,
The position where the label 28 is sent out or the position where the label 28 is cut may be determined.

Further, the color and shape of the mark 30 are not limited to the above-described embodiment,
Any device can be used as long as it changes the amount of light received.

[0023]

As described above, according to the printer of the present invention, since the light transmitted through the printing paper is reflected by the reflecting means toward the light receiving means, a large amount of reflected light from the printing paper can be secured. it can. As a result, the mark can be reliably detected, and printing can be accurately performed at a predetermined position on the printing paper based on the timing at which the mark is detected.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a structure of an embodiment of a printer according to the present invention.

FIG. 2 is a perspective view of the label sheet shown in FIG. 1;

FIG. 3 is a schematic structural diagram showing a structure of a sensor and a reflector shown in FIG. 1;

FIG. 4 is an explanatory diagram for explaining the operation of the printer according to the present invention.

FIG. 5 is an explanatory diagram for explaining the operation of the printer according to the present invention.

[Description of Signs] 10 printer, 12 printing unit, 18 label paper, 2
6 Mount, 28 Label, 30 Mark, 36 Sensor, 38 Reflector, 40 Light-emitting element, 42 Light-receiving element

Claims (1)

[Claims] 1. A light emitting means for emitting light toward a printing paper, and a light receiving means for receiving light emitted by the light emitting means and reflected by the printing paper, wherein a change in the amount of light received by the light receiving means is provided. And a reflecting means for reflecting light emitted from the light emitting means and transmitted through the printing paper toward the light receiving means.