JPH03275A - Printer - Google Patents

Abstract

PURPOSE:To make possible the detection of paper width and an initial carriage position using a single sensor by arranging a member to be detected for detection of an initial carriage position near one end of a platen and at the same time, mounting a detection sensor for detection of paper width and said member on the carriage. CONSTITUTION:If a printer is switched ON and paper is supplied using a paper transport mechanism in such a manner that the paper is wound around a platen 3, the carriage 6 is moved by the activation of a paper detection switch, and the width of the paper is detected by a detection sensor 20 and CPU during the movement of the carriage 6. After this, the carriage 6 is again moved, and the detection sensor 20 is positioned against a plate to be detected 21. Then light emitted by a light emitter on the detection sensor 20 is reflected by the plate 21. This results in the more rapid reception of light by a light receiver. After this, the location of the carriage 6 at an initial position is detected by CPU, and the drive of the carriage 6 is immediately stopped. Subsequently, it is possible to place the carriage 6 at an initial position.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printer that prints on paper on a platen using a print head mounted on the carriage while moving the carriage along the platen. The present invention relates to a printer that performs printing by detecting the paper width and the initial position of a carriage.

(Prior Art) There are various types of printers mentioned above, such as wire dot printers, thermal printers, and inkjet printers. The carriage carrying print heads such as heads, thermal heads, inkjet heads, etc. must be positioned at an initial position near one end of the platen in the longitudinal direction, and the carriage must be moved according to the width of the paper to perform printing. It won't happen.

FIG. 3 is an exploded perspective view showing a general type of wire dot printer among the various printers mentioned above, in which bearing frames 2 are erected almost vertically at both left and right ends of the upper surface of a frame 1, respectively. This bearing frame 2 has
A cylindrical platen 3 is rotatably held by shaft portions 3a at both ends. Further, the bearing frame 2 includes:
A carriage shaft 4 and a support post 5 are respectively installed parallel to the platen 3 and closer to the platen.
A carriage 6 is attached to the carriage shaft 4 and the support post 5 so as to be able to reciprocate along the platen 3. A wire dot head 7, which is a printing head (not shown), is mounted on the carriage 6 at a position close to the platen 3 so as to face the platen 3.

An endless drive belt 8 is connected to the lower surface of the carriage 6, and the drive belt 8 drives the carriage 6 back and forth along the carriage shaft 4.

A cover frame 9 whose top surface is open is attached above the frame 1, and a front cover 10 whose rear end is located approximately above the platen 3 is mounted in front of the top surface of the cover frame 9. It is attached so that it can rotate freely around its front end. Furthermore, a paper discharge guide 11 is arranged on the upper surface of the cover frame 9 to guide the paper after printing is completed, and a rear end portion of the cover frame 9 is provided with a paper discharge guide 11 for feeding the paper before printing. A paper guide 12 is foldably arranged.

According to the above-described configuration, the paper supplied from the paper guide 12 is wound around the outer periphery of the platen 3, and the wire dot head 7 is activated based on a desired print signal while the carriage 6 is moved at a predetermined speed. It can be driven to perform printing.

The paper after printing is discharged from between the paper discharge guide 11 and the front cover 10.

By the way, as mentioned above, in order to print at a predetermined position on paper, it is necessary to position the carriage at the initial position and move the carriage according to the width of the paper. There are two types of printers: one in which the paper width is set in advance by operating the printer's keyboard, and the other in which the paper width is detected by a paper width detection sensor mounted on a carriage. Among these, the main parts of a conventional printer that detects the paper width of paper using a paper width detection sensor are shown in FIGS. 4 and 5.

In FIGS. 4 and 5, carriage shirts 1 to 4
A wire dot head 7 facing the platen 3 is mounted on the carriage 6 supported by the support post 5, and a ribbon cassette 13 is mounted on the carriage 6 so as to surround the wire dot head 7. It is installed. A ribbon mask 14 is erected on the front part of the carriage 6 to prevent the ink ribbon in areas other than the front of the wire dot head 7 from coming into sliding contact with the paper. A paper width detection sensor 15 made of a reflective photosensor or the like is mounted on the carriage 6 so as to face the platen 3 .

On the other hand, on the frame 1 near one end of the movement range of the carriage 6, an initial position detection sensor 16 made of a transmission type photosensor or the like is installed so as to face directly below the carriage 6. Further, a light shielding piece 17 is vertically provided at the lower part of the key 1r ridge 6 to block light from the light emitter 16A of the initial position detection sensor 16 to the light receiver @16B when the carriage 6 is at the initial position. .

Note that the detection signals from both the sensors 15 and 16 are input to a CPU (not shown) of the printer.

In order to detect the paper width of the paper using the paper width detection sensor 15 and position the carriage 6 to the initial position using the initial position detection sensor 16, first turn on the printer switch and use the paper transport mechanism (not shown). When paper is fed so as to be wound around the platen 3, a paper detection switch (not shown) detects the feeding of the paper, and the carriage 6 is moved.While the carriage 6 is moving, the paper width detection sensor 15 detects the width of the paper. Detected.

The paper width detection signal from this paper width detection sensor 15 is C.
The PIJ is manually operated, and the CPIJ controls the reciprocating movement of the carriage 6 during printing so as to correspond to the paper width of the paper.

Then, as the carriage 6 is moved again, light is emitted from the light emitter 16A of the initial position detection sensor 16 to the light receiver 516B, and when the carriage 6 is positioned at the initial position in this state, the light is attached to the carriage 6. The light shielding piece 17 faces between the light emitter 16A and the light receiver 16B of the initial position detection sensor 16, and extends from the light emitter 16A to the light receiver '1.
Blocks the light received by 6B. Then, a detection signal is output from the initial position detection sensor 16 to the CPLI, and the drive of the carriage 6 is immediately stopped, and the carriage 6 is positioned at the initial position.

[Problem to be solved by the invention]

However, in the conventional method described above, the paper width detection sensor 1 is used to accurately print at a predetermined position on the paper.
This requires two expensive sensors: 5 and the initial position detection sensor 16, which poses a problem in that the printer is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to overcome the problems of the conventional printers described above, and to provide a printer that can be manufactured at low cost by detecting the width of paper and the initial position of the carriage using one sensor. .

(Means for Solving the Problems) In order to achieve the above-mentioned object, the printer according to the present invention has the following features:
In a printer in which a print head is mounted on a carriage that can reciprocate along a platen, and the carriage is moved to detect the width of paper and the initial position of the carriage before printing, the carriage is located near one end of the platen. The present invention is characterized in that a member to be detected is disposed for detecting the initial position of the paper, and a detection sensor is mounted on the carriage to detect the paper width of the paper and the member to be detected.

[For production]

In order to detect the paper width of paper and the initial position of the carriage using the present invention configured as described above, paper is supplied to the platen, and when the paper supply is detected by a paper detection switch or the like, the carriage is moved. , while the carriage is moving, the paper width of the paper is detected by the detection sensor. Then, the carriage is moved again, and the detection sensor faces the member to be detected, thereby detecting the initial position of the carriage.

In this way, the paper width of the paper and the initial position of the carriage can be detected with one detection sensor, so the printer can be manufactured at low cost.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings. Note that the same components as those of the conventional device described above are denoted by the same reference numerals in the drawings, and the explanation thereof will be omitted.

1 and 2 show the main parts of the printer according to the present invention. A ribbon mask 14 is erected on the front part of the carriage 6, and the carriage 6 near the ribbon mask 14 is shown in FIG. A detection sensor 20 made of a reflective photosensor or the like is mounted so as to face the platen 3. This detection sensor 20 includes, for example, a light emitter (not shown) that emits light in the direction of the platen 3, and a light receiver (not shown) that receives light when the light from the light emitter is reflected by some object.
(not shown), and this detection sensor 2
o is electrically connected to a CPU (not shown) of the printer. The light emission timing from the light emitter of the detection sensor 20 and the light reception timing at the light receiver are respectively input to the CPU, and in paper width detection, the light reflected from the paper and the light reflected from the platen 3 are CPU calculates the time difference between light reception and light reception.
The paper width of the paper is detected by calculating in .

Near one end of the platen 3, that is, the platen 3
The detection sensor 20 mounted on the carriage 6 is extended in the axial direction on the side facing the carriage 6.
A detection target plate 21, which is an example of a detection target member, is disposed at a height that can face the detection target member. The position of the detection plate 21 in the axial direction of the platen 3 is such that the carriage 6 is at an initial position when the detection sensor 20 faces the detection plate 21.

Next, the operation of this embodiment having the above-described configuration will be explained.

To detect the paper width of the paper and the initial position of the carriage 6 before printing, first turn on the printer switch and set the paper so that it is wound around the platen 3 by the paper transport mechanism (not shown). When the paper is supplied, the carriage 6 is moved by the action of a paper detection switch (not shown) or the like, and while the carriage 6 is moving, the width of the paper is detected by the detection sensor 20 and the CPU.

Then, the carriage 6 is moved again, and the detection sensor 20
is opposed to the detection target plate 21, and the light emitted from the light emitter of the detection sensor 20 is reflected by the detection target plate 21, so that the light is received by the light receiver more quickly than before.

Therefore, by inputting the light reception signal from this light receiver to the CPU, the CPU detects that the carriage 6 is located at the initial position, and the driving of the carriage 6 is immediately stopped. As a result, the carriage 6 can be positioned at the initial position.

As described above, according to this embodiment, since the paper width of the paper and the initial position of the carriage can be detected by one detection sensor 20, only one expensive sensor is required.
Printers can be manufactured at low cost.

Note that the present invention is not limited to the embodiments described above, and various changes can be made as necessary. For example, the detected member may be a seal instead of the detected plate 21 in the embodiment. Further, the detection sensor may be of an illuminance detection type that can detect the reflectance of light of the anti-rJI object.

(Effects of the Invention) As described above, according to the present invention, the paper width of the sheet and the initial position of the carriage can be detected with a single sensor, so that it has the practical effect of being able to be manufactured at low cost.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the printer according to the present invention, FIG. 1 is a plan view of the main part, and FIG.
Figure 3 is an exploded perspective view of a general wire dot printer, Figures 4 and 5 are conventional printers, Figure 4 is a plan view of the main parts, and Figure 5 is a side view of the main parts. FIG. 5 is a side view of FIG. 4; DESCRIPTION OF SYMBOLS 1... Frame, 3... Platen, 4... Carriage shaft, 5... Support post, 6... Carriage, 7... Wire dot head, 13... Ribbon cassette, 15... - Paper width detection sensor, 16... Initial position detection sensor, 17... Light shielding piece, 20... Detection sensor, 21... To be detected plate.

Claims (1)

[Claims] In a printer in which a print head is mounted on a carriage that can reciprocate along a platen, and the carriage is moved to detect the width of paper and the initial position of the carriage before printing, the carriage is located near one end of the platen. What is claimed is: 1. A printer comprising: a member to be detected for detecting the initial position of the printer; and a detection sensor capable of detecting the paper width of the sheet and the member to be detected, respectively, mounted on the carriage.