JPS62226764A - Recording device - Google Patents

Abstract

PURPOSE:To prevent the reduction in the detection accuracy due to dirt by projecting an index plate stored in a prescribed position by the movement of a carriage and generating a read home position signal by a read means provided to the carriage. CONSTITUTION:The index plate 9 projected by utilizing the movement of the carriage only when the carriage 3 moves in a prescribed range and stored when the carriage 3 is in other positions is provided to a prescribed position of a base of a recorder, and a read means 10 reading optically the projecting index plate 9 and generating a home position signal based thereupon is provided on the carriage 3. A wipe means such as a felt or a cloth is fitted aditionally to the storage part of the index plate 9 and every time the index plate 9 is stored, the index part (reflection face) is wiped off. Thus, the index plate is kept always to the state of he initial reflecting density.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to means for setting the home position of a carriage in a recording device such as a printer, typewriter or facsimile.

[Prior art]

As a recording device such as a printer, electronic typewriter, or facsimile, a recording head is mounted on a carriage that moves along a platen, and the recording head is driven in synchronization with the main scanning movement of the carriage to record on a sheet. There are several configurations.

In this type of recording apparatus, the position of the carriage is calculated based on a home position, that is, a stop position of the carriage set outside the recording area, and the operations of the carriage, the recording head, etc. are controlled based on this.

Therefore, it is required to accurately and quickly detect the home position of the carriage.

Conventional home position detection methods include optical detection or electrical reading of a mechanical contact switch, but with optical methods, the index plate is constantly exposed, so detection accuracy may be affected by dirt. Deterioration is a problem, and the method using a contact type sinch has a problem of large accuracy errors due to aging.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical home position setting means that can solve the problems of the prior art and eliminate deterioration in detection accuracy due to dirt.

〔overview〕

The present invention provides a recording apparatus in which a recording head is mounted on a carriage that moves along a platen, and the recording head is driven in synchronization with the main scanning movement of the carriage. By protruding the indicator plate and reading the indicator plate with a reading means provided on the carriage, the home position 3 is generated.
This aims to achieve the above objectives.

〔Example〕

FIG. 1 shows the main part of an embodiment in which the present invention is applied to a thermal transfer printer.

In FIG. 1, guide rails 2, 2 are installed in front of and parallel to the platen 1, and a recording head 4 is mounted on a carriage 3 that is guided and supported by the guide rails.

The platen 1 is used to back up sheets of recording media such as paper or thin plastic plates, and the illustrated platen 1 also serves as a sheet feeding roller.

The recording head 4 is a thermal head, and on its front surface is a dot forming means consisting of a plurality (for example, 24 or 32) of electrothermal transducers (heating resistors, etc.) arranged in one or two vertical rows. It is provided.

Further, a ribbon cassette 5 is replaceably mounted on the carriage 3, and includes a recording head 4 and a platen 11? ; The ink ribbon 6 is configured to be fed between it and a sheet (not shown) on one side.

The recording head 4 is connected to the platen 1 via an ink ribbon 6.
The amplifier is driven to be displaced between a down position (recording position) where it is pressed against the upper sheet and an amplifier position (non-recording position) where it is separated from the sheet.

The recording device includes a control circuit (CPU) 7 that controls the entire device.
This control circuit 7 and the electronic 1m KL on the carriage 3 such as the recording head 4 are electrically connected by a flexible cable 8.

In this manner, the recording apparatus shown in FIG. 1 is configured such that the recording head 4 is mounted on the carriage 3 that moves along the platen 1, and the recording head 4 is driven based on print data in synchronization with the main scanning movement of the carriage. ing.

During recording, the recording head 4 is pressed against the sheet on the platen 1 via the ink ribbon 6 and moves in the main scan, and the ink ribbon 6 is wound and driven in synchronization with this movement.

When not recording, such as when the carriage returns or when the carriage runs dry,
The recording head 4 is separated from the platen 1, and winding of the ink ribbon 6 is also stopped.

However, the carriage 3 is located at a predetermined position on the base of the recording device.
An indicator plate 9 is provided which is projected using the movement of the carriage only when the carriage 3 moves within a predetermined range, but which is held in a retracted state when the carriage 3 is in any other position.

On the other hand, a reading means 10 is provided on the carriage 3 for optically reading the protruding index plate 9 and generating a home position signal based on the reading. This reading means 10 can be configured with a reflective sensor made of, for example, an LED and a CCD.

That is, the recording apparatus shown in FIG. 1 causes the indicator plate 9 stored in a predetermined position to protrude by moving the carriage 3, and generates a home position signal by reading the indicator 9 with a reading means provided on the carriage. It is configured like this.

The position of the carriage 3 when the indicator plate 9 (protruding state) is read by the reading means 10 is set to the home position of the carriage or a position in a specific relative relationship thereto.

2 shows the state in which the t mark plate 9 is attached, FIGS. 3 and 4 show the state in which the second mark plate 9 is retracted and protruded by the carriage 3, and FIG. Indicates a surface (reflective surface).

In FIG. 2, the index plate 9 is rotatably supported around a shaft 11, and is normally held at a position biased clockwise by a return spring 12 as shown.

As shown in the figure, the indicator plate 9 has an L-shape with arm parts on both sides of the shaft 11, and when the indicator part (reflective surface) 9A is stored, the other end arm part 9B that protrudes upward has a carriage. 3 (1jI1. cam portion described) is provided with an engaging pin 14 that comes into contact with the cam portion.

Further, a wiping means 15 made of felt or cloth is attached to the inside of the cover 13, that is, the t mark section 9A housing section, and each time the index plate 9 is stored, the index section (reflective surface) 9A is cleaned. It can be cleaned.

Next, the operation will be explained with reference to FIGS. 3 and 4.

First, the carriage 3 is provided with a cam 16 that contacts the engagement pin 14 and penetrates the return spring 12 to rotate the index plate 9 counterclockwise to a protruding state.

The carriage 3 moves along the guide rail 2.2 in the direction of arrow A (
1 and 3), the cam 16 provided on the carriage 3 collides with the engagement pin 14, hits the return spring 12 and rotates the index plate 9, causing the carriage to retract as shown in FIG. drive from the state to the protruding state shown in FIG.

A reading means 10 on the carriage 3 detects the amount of reflected light while the carriage is moving, and constantly compares the read signal with data from the control circuit 7.

By the way, as shown in FIG. 5, the index portion (reflective surface) 9A of the index plate 9 has a binary density divided into a surface X having a maximum reflectance and a surface Y having a minimum reflectance. It has a structure that allows correction for 10 reading outputs.

After the indicator plate 9 protrudes as shown in Fig. 4, the carriage 3
When the reading means 10 moves, the indicator portion (reflective surface) 9
The amount of reflected light from A is detected, and by comparing it with the data of the control circuit 7, it is recognized that it is the indicator plate area, and the maximum value is corrected with respect to the reference amount of reflection.

Furthermore, the carriage 3 continues to move, and the reading means 10
The amount of light is detected and compared with the data of the control circuit 7, and the position where the amount of light reflected from the index plate 9 matches the range of data of the control circuit is recognized as the home position or a target position having a specific correlation with the home position. Then, correction is performed using that data as the minimum value for the reference reflection amount.

That is, the index plate 9 also serves as a reference output calibration reflection plate for correcting the read output of the image reading means.

By reading the indicator plate 9 as described above, a home position signal indicating arrival at the home position or arrival at a position in a specific relationship with the home position is generated, and the carriage 3 and the recording head 4 are operated in response to this signal. is controlled.

According to the embodiment described above, the 1-hour signboard 9 is made retractable and its surface is cleaned each time it is retracted, so that the 1-h signboard can always be maintained at the initial reflection density, and the light source It is now possible to easily correct deterioration.

Although the illustrated embodiment uses the platen 1 which also serves as a sheet feeding roller, the present invention can be similarly applied to a recording apparatus having a fixed type (or 112-sided) platen.

Further, the present invention can be widely applied regardless of the recording method such as a thermal recording device, an inkjet recording device, or a wire dot recording device.

〔effect〕

As is clear from the above description, according to the present invention, when the home position is optically detected using the reflected light from the index plate installed at a predetermined position, the index plate is prevented from becoming dirty and the state of the initial reflection density is determined. Provided is a recording device that can be maintained and easily compensated for deterioration of a light source.

[Brief explanation of drawings]

FIG. 1 shows the main parts of a recording device according to an embodiment of the present invention;
1 is a perspective view, and FIG. 2 is a partially cutaway perspective view showing the retracted (installed) state of the indicator plate in FIG. A schematic elevational view showing the operational relationship, and FIG. 5 is an explanatory view showing the reflective surface of the T signboard. 1...--Platen, 3-------Carriage, 4--- Recording head, 9-----1 index plate, 9A--1-- --- Pilgrimage sign part (reflective surface), 10
・・・・−・−・Reading means, 13−・−−・−−
--One cover, 14---...Engagement bin, X.
・〜・・・−・Maximum reflectance surface, Y−・−・−Minimum reflectance surface. Agent Patent Attorney Yasushi Ooto Takeno De Itte U Shizui (Format) June 18, 1986 3, Relationship to the case of the person making the amendment Patent Applicant Address 3 Shimomaruko, Ota-ku, Tokyo 30-2, Chome Name (100) Canon Co., Ltd. Representative Ryu Sanbu 4, Agent Address: 101

Claims (2)

[Claims] (1) In a recording device in which a recording head is mounted on a carriage that moves along a platen, and the recording head is driven in synchronization with the main scanning movement of the carriage, an index plate stored in a predetermined position is moved by the movement of the carriage. A recording device characterized in that a home position signal is generated by reading the index plate with a protruding reading means provided on a carriage. (2) The recording apparatus according to claim 1, wherein the index plate also serves as a reference output calibration reflection plate for correcting the read output of the image reading means.