JPS60176789A - Printing paper detector for printer - Google Patents

Abstract

PURPOSE:To detect the presence or absence of a printing paper on a platen and detect also the presence or absence of the paper in the width direction of the paper, by providing a light-emitting element and a light-receiving element in a printing mechanism part moved along the platen. CONSTITUTION:A photo-sensor 23 is fitted into a recessed part provided at the lower part of the rising part 12b of a support member 12 for the printing mechanism part on the side of the moving direction of the printing mechanism part in a printing operation of a thermal head 14. A photo-sensor 23 is provided with a light-emitting element 26 and a light-receiving element 27, and the presence or absence of the printing paper is detected from a signal generated when the light emitted from the element 26 is reflected by the printing paper and received by the element 27.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a printing paper detection device for a printer that detects the presence or absence of printing paper in a printer.

[Technical background of the invention]

Conventionally, for example, in a thermal transfer printer, a platen that receives printing paper is rotatably provided in the main body case, and a printing mechanism consisting of a support body having a Therma μ head and a carriage that supports it is attached to the platen. A printing paper detection device is provided to be located in front of the platen and run along the platen, and has a contact terminal at the rear part of the platen among the paper guide parts provided around and behind the platen in this case. The printing paper is mounted on the platen through the paper guide section. The printing paper detection device detects the presence or absence of printing paper on the paper guide section based on the contact terminal coming into contact with the printing paper through the opening of the paper guide section.

[Problems with background technology]

However, since the conventional printing paper detection device described above is fixedly disposed behind the platen, there is a problem that it cannot detect the presence or absence of printing paper particularly in the width direction of the printing paper mounted on the platen, and For example, when a narrow printing paper is attached to a platen and printing is performed using the thermal head, the printing operation is performed with the thermal μ head positioned beyond the width of the printing paper. Unfortunately, in this case, there is a risk of damaging the platen.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and therefore, its purpose is to be able to detect the presence or absence of printing paper in the width direction of the printing paper on the platen, and therefore print 4! according to the width of the printing paper. l! It is also possible to control the printing operation and movement of the printing mechanism, thereby enabling control such as stopping the printing of the printing mechanism when the printing mechanism comes off the printing paper. The present invention provides a paper detection device.

[Summary of the invention]

The present invention provides a printing mechanism that runs along a platen that receives printing paper, and includes a light emitting element that emits light toward the printing paper and a light receiving element that receives light reflected by the printing paper and generates a signal. The device is characterized in that the presence or absence of printing paper on the platen is detected based on the signal emitted by the device.

[Embodiments of the invention]

A first embodiment of the present invention applied to a thermal transfer printer will be described below with reference to FIGS. 1 to 4.

First, in Figures 1 and 2, 1 is the main case, 2
is a platen, and this differential gear 2 is rotatably supported via a shaft 4 on a platen support base 3 provided within the main body case 1. 5 is a printing paper inserted from the paper guide section 6 at the rear of the platen 2 and received by the front surface of the platen 2;
7 is a paper presser. Reference numerals 8 and 8 designate a pair of guide trays .mu., which are supported and fixed to a tray support 9 provided in the main body case 1 so as to be located in front of the platen 2 and arranged along the platen 2. Reference numeral 10 denotes a substantially rectangular carriage, which is provided so as to be movable in the longitudinal direction of the guide tray μ8 by being inserted into and supported by the guide tray /L/8.8 at the lower part;
is reciprocated via a shaft (L/) 11 by a motor (not shown). Also, carriage 10
A concave cutout 10B is formed in a portion on the platen 2 side. Reference numeral 12 denotes a support member that constitutes the printing mechanism section 13 together with the carriage 10, and as shown in FIG. On the rear surface of the rising portion 12b, a Thermanon head 14, which is the main printing portion, is provided so as to face the platen 2 and protrude slightly rearward. The support member 12 is located within the notch 10& of the carriage 10, and is rotatable in the front-rear direction of the carriage 10 via a shaft 16 passing through a through hole 15 formed in the base portion iza of the support member 12. Although not shown, the support member 12 is supported by a pressure mechanism provided on the carriage 10 to press the platen z.
The Therma μ head 14 is rotated to the side and the printing paper 51 is rotated to the side.
C It is narrowed to make pressure contact. In addition, 17 is the support member 1
2 and the carriage 10, which further supports the support member 12 with respect to its Thermaμ head 1.
4 is biased in a direction away from the printing paper 5. Thus, the entire printing mechanism section 13 consisting of the carriage 10 and the support member 12 runs along the platen 2 (#) 7, and prints on the printing paper 5 with its thermal head 14. . On the other hand, 18 is a ribbon storage cassette detachably mounted on the carriage 10 by pressing springs 19, 19, 20 is a thermal ink ribbon, and the thermal ink ribbon 20 is attached to the ribbon storage cassette 18.
The rack is wound on the winding sheet 9-/L'21 and the feeding sheet IJ-1v22, which are provided in the interior, respectively, in a stretched state, and the portion where the rack is stretched between both μ21 and 22. is passed through the THERMY head 14 portion of the support member 12. Further, although not shown in the drawings, the carriage 10 includes a motor for driving the winding le 21 and the feeders -lv, 22 in order to wind the thermal ink ribbon 20 onto the winding -μ21. It is provided.

Now, in FIG. 3, 26 is a photosensor, which is formed on the right side of the lower part of the upright structure 12b of the support member 12, that is, on the traveling direction side of the print mechanism 16 during the printing operation of the thermal head 14. It is located within the four mounting parts 24 and is mounted with its front face facing the platen 2 side. As shown in detail in FIG. 4, this photosensor 23 has a light emitting diode 26 as a light emitting element and a light emitting diode 26, which is a light emitting element, inside a short cylindrical sensor case 25 that is vertically partitioned by a light shielding wall 25a. A phototransistor 27, which is a light receiving element that receives received light and emits a signal, is provided. Note that 28.28 is a transparent plate attached to the front opening of the sensor case 725. This photosensor 25'l-1 travels along the platen 2 together with the printing mechanism section 13, and at this time, light is emitted from the light emitting diode 26 toward the printing paper 5 side on the platen 2. The phototransistor 27 receives the light reflected by the printing paper 5 and issues a signal, thereby detecting the presence of the printing paper 5 on the sieve platen 2. On the other hand, if the light emitted from the light emitting diode 26 is not reflected from the printing paper 5, for example, the position of the photosensor 26 is
When the phototransistor 27 is positioned to the right of the right edge of the printing paper 5 beyond the width of the upper printing paper 5, the phototransistor 27 emits a signal based on the fact that it does not receive the reflected light from the light emitting diode 26. Printing paper 5 on 2
It is detected that is not at that position. In this case,
No printing operation is performed by the Thermanon head 14, and the entire printing mechanism section 16 is moved to the printing start position.

According to this embodiment, a light emitting diode 26 that emits light toward the printing paper 5 side and a print mechanism 13 that runs on the platen 2 that receives the printing paper 5 are installed. A phototransistor 27 that receives the emitted light and emits a signal is provided, and the presence or absence of the printing paper 5 on the platen 2 is detected based on the emitted signal, so the printing paper detection device is installed at the rear of the platen. Unlike in the past, which was fixedly disposed on the platen 2, the presence or absence of the printing paper 5 in the width direction of the printing paper 5 on the platen 2 can also be detected. Therefore, it is also possible to stop the printing operation when the thermal head 14 comes off the printing paper 5, and in this case, it is possible to eliminate the risk of damaging the platen 2. In addition, particularly according to this embodiment, the light emitting diode 26 and the phototransistor 27 are provided on the support member 12 where the thermistor v head 14 which is the printing main part of the printing mechanism section 13 is located. Since the transistor 27 is located close to the print paper 5 and the thermistor head 14, the presence or absence of the print paper 5 can be detected more reliably, and the The printing operation control and movement control of the printing mechanism section 13 can also be made accurate.

FIG. 5 shows a second embodiment of the present invention. In this second embodiment, a photo sensor 26 similar to that in the first embodiment is provided on the carriage 10 via a mounting base 29. It is different from. In this case, the photosensor 23 is located on the right side of the support member 12 on the carrier and Fuji 10.

This second embodiment also has basically the same effects as the first embodiment.

Although the present embodiment has been described with respect to a thermal transfer printer, the present invention is not limited to this, and may be applied to, for example, a Therma μ printer that does not use a Therma μ ink ribbon, an impact dot printer, a Dizzy Hoino V printer, or an inkjet printer. This can be used in printers such as printers in which the printing mechanism moves relative to the platen.

In addition, the present invention can be implemented with appropriate changes within the scope of the invention.

〔Effect of the invention〕

As is clear from the above description, the present invention provides a light-emitting element that emits light toward the printing paper in a printing mechanism that runs along a platen that receives printing paper.

A light-receiving element that receives light reflected by the printing paper and emits a signal is provided, and the presence or absence of the printing paper on the platen is detected based on the emitted signal. It is also possible to detect the presence or absence of printing paper in the width direction, so it is possible to control the printing operation and movement of the printing mechanism according to the width of the printing paper. This has the excellent effect of making it possible to stop printing by the printing mechanism section.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a perspective view of the entire thermal transfer printer, FIG. 2 is an enlarged plan view of the main parts, and FIG. 3 is an enlarged perspective view of the support member. 4 are enlarged longitudinal sectional side views of the photosensor, and FIG. 5 is an enlarged perspective view of the main parts showing a second embodiment of the present invention. In the drawing, 2 is a platen, 5 is a printing paper, 10 is a carriage, 12 is a support member, 16 is a printing mechanism section, 14 is a thermal/V head (printing main body part), 26 is a light emitting diode (light emitting element), and 27 is a Phototransistor (light receiving element).

Claims (1)

[Scope of Claims] 1. A light-emitting element that emits light toward the printing paper side and a signal that receives the light reflected by the printing paper in a printing mechanism section that runs along a platen that receives printing paper. What is claimed is: 1. A printing paper detection device for a printer, comprising: a light receiving element that emits light, and detects the presence or absence of printing paper on the platen based on the emitted signal. 1. A printing paper detection device for a printer as set forth in claim 1, wherein the light emitting element and the light receiving element are provided in a member of the printing mechanism section where the printing main part is located.