JPS59174375A - Printing head position detection system - Google Patents

Abstract

PURPOSE:To simplify and make easier the position adjustment of a detector as well as to permit the simple discrimination of head position by detecting a printing head discriminator provided on the belt for driving the printing head by a common sensor. CONSTITUTION:On a motor-driven belt 10 on which a printing head 1 is fixedly provided through a carrier 2 and serving to move the head 1 to a desired printing position on a platen, one, two, or three head position discriminators h1-h3 in the form of through holes are provided on both ends and the central part. These discriminators h1-h3 are optically detected by a common sensor S and the position of the head 1 is simply discriminated. Since the discrimiators h1- h3 can be mechanically formed concurrently and exactly, the adjustment of their relative position with the sensor S can be simplified and made easier.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a print head position detection method, and in particular, the present invention relates to a print head position detection system, and in particular, a belt that drives the print head is provided with a position identifier detectable by a sensor such as a hole, so that a common one can be detected. This is detected by two sensors to detect the position of the print head.

[Conventional technology and problems]

Conventionally, in serial printers and the like, a print head 1 is supported on a carrier 2, as shown in FIG.

This carrier 2 is fixed to the belt 3, and the belt 3 is moved by rotating the pulley 4 by the motor 5.
4, 4' to move the print head 1 to the right or left. The print head 1 then prints on a paper surface (not shown) located on the platen 6.

When printing from left to right with a sheet of paper placed on the platen 6, if printing is done only on the left half or right half of this sheet of paper, □ as shown in Figure 2, There is a glazed printing mode, such as when two sheets of paper LP and RP are placed and printing is performed on only one of them. Therefore, it is necessary to detect the position of the print head 1 according to these printing modes.

As shown in FIG. 1, sensors S1, S2. Place S3 at the left end, center, and right end positions of the print head, respectively.
A light shielding plate C provided on the carrier 2 detects which of the sensors 5l to 8i is in a light shielding state to detect the position of the print head l.

However, in such a detection method, Sl-S3
Three sets of sensors are required, and three sets of sensors may be required for each sensor S1 to S3, including sensor position adjustment during production, cables to the control circuit, and three control circuit elements. This has the disadvantage that it is not only complicated but also difficult to adjust.

[Purpose of the invention]

The purpose of the present invention is to improve these drawbacks.

A print head position detection method that allows one sensor to easily identify whether the print head is in one of several predetermined positions, such as left, right, or center, and allows adjustment with a single position adjustment. The goal is to provide the following.

[Structure of the invention]

In order to achieve this object, the print head position detection method of the present invention detects whether the print head is at a plurality of predetermined positions on the print head drive belt in a printing device equipped with a print head and a print head drive belt. With the position identifier of multiple types of odes that can be classified by job.

A common sensor is provided to detect these position identifiers.

The present invention is characterized in that the print head position is detected based on the output of this common sensor.

[Embodiments of the invention]

An embodiment of the present invention will be described based on FIGS. 3 to 6.

FIG. 3 is an explanatory view showing the position of the print head and the position of the belt hole, FIG. 4 is an explanatory view of the sensor, FIG. 5 is a configuration diagram of an embodiment of the present invention, and FIG. 6 is an explanatory view of the operating state.

In the figure, the same reference numerals as in the others indicate the same parts, 10 is a belt, 11 is an external device, 12 is a microcomputer, and 13 is a control program storage unit.

14 is a space control section, 15 is a driver, and 16 is a senna output detection circuit.

As shown in FIG. 3, the carrier 2 that supports the print head 1 is fixed to the bell) 10, and has three types of holes.
'-13 is formed. This hole Al consists of one through hole, h2 consists of two through holes,
A5 consists of three through holes. And these holes hx -%-A3 are the light emitting diode LD of sensor S.
10 so as to pass between the light receiving diode RD and the light receiving diode RD. When the print head 1 is at the left end position, as shown in FIG. 3 (a), the hole h3 is located at the sensor S part, and as shown in FIG. 3 (b), the print head 1 is at the center position. At one time, the hole h2 is located in the sensor S portion, and as shown in FIG. 3(c), when the print head 1 is at the light end position, the hole Al is located in the sensor S portion.

The microcomputer 12 is controlled by a program stored in a control program storage section 13 configured in a ROM.

The space control unit 14 controls the printing head 1 from left to right or from right to left during printing.

Controls the driver 15 of the motor 5 that drives the belt 10.

The senna output detection circuit 16 detects the pulse output detected from the sensor S, and as shown in FIG.
output, and as shown in (b), insert the sensor S into the hole h2.
When the hole Al passes through the sensor S, it outputs two pulses, and as shown in (a), when the hole Al passes through the sensor S, it outputs one pulse.

The control program storage section 13 stores a microprogram for controlling the microcomputer 12, and is constituted by, for example, a ROM. This control program storage section 13 contains a control program for when the print head 1 prints from the left end position to the right, a control program for the print head 1 to print from the center position, and a control program for the print head 1 to print from the center position.
In addition to control programs necessary for the print head to perform various types of printing, such as a control program for printing leftward from the light end position, a control program for printer initialization is stored.

This printer initialization is for moving the print head 1 to the left end position as shown in FIG. 3(A) prior to printing. For example, the print head 1 may be stopped at a position other than the left end position due to a power outage, etc., so after turning on the power, first move the belt 10 to the left and stop it when the sensor S detects the hole h3. , place the print head l in the left end position.

Next, the operation of the present invention shown in FIG. 5 will be described with reference to FIG. 6 for an example in which the sheets are located separately on the left and right sides of the center of the print area as shown in FIG. 2, and printing is performed only on the right sheet of paper. Explain according to the following.

(1) First, turn on the power. As a result, a program for initializing the printer is read from the microcomputer 12 (i-control program storage section 13), and the print head 1 is adjusted as shown in FIG. 3(a).

Place it in the left end position.

(2) Then, the microcomputer 12 decodes the right side paper print instruction command transmitted from the external device 11, and sequentially reads microprograms based on the command from the control program storage section 13, and controls are performed based on this. .

(3) This microprogram first controls the space controller 14 to move the belt 10 from left to right in order to move the print head 31 in the state shown in Fig. 3 (a) to the position shown in Fig. 3 (b). Then, by driver 15 υ
The rotation of the motor 5 is controlled so that the belt 10 moves from left to right. This causes the print head 1 to be moved to the right.

(4) At this time, in order to monitor whether or not the sensor S has detected the hole h2, the microcomputer 12 checks that the sensor output detection circuit 16 transmits the signal. The print head 1 will then control the space controller 14 to be moved to the right until the pulse is transmitted.

(5) Count the number of pulses when they are transmitted from the sensor output detection circuit 16. And this is 27
In the case of Sorus output, the print head 1 is located in the state shown in Figure 3 (b), so using this state as a starting point, print data is transmitted to the print head 1 from a line buffer (not shown), and the right side is output. Execute the desired printing on the paper.

(6) In (5) above, the sensor output detection circuit 1
If the ・ξ rus number transmitted from 6 is not 2, then Fig. 3 (
As shown in (a) or (c), the print head 1 is not located at the center position, so the alarm is not output.
The printer will inspect this printing device.

Incidentally, instead of using the holes to detect the position of the print head as described above, it is also possible to add a mark or the like to the hole and detect the position of the print head using a reflective sensor or the like.

〔Effect of the invention〕

In the present invention, it is only necessary to process the belt for transmitting the rotation of the motor to the print head, and this process can be performed mechanically at three positions simultaneously. Therefore, the position of the hole, mark, etc. can be determined accurately by the machine, so it is only necessary to adjust the relative relationship between the sensor and any one hole, etc.

Compared to the conventional case in which all three sensors had to be adjusted, the number of sensors can be reduced and the control circuit configuration can be simplified, and the adjustment can be made very simple.

[Brief explanation of the drawing]

Figure 1 is a conventional serial printer, Figure 2 is an explanatory diagram when printing on one of two sheets of paper, and Figure 3 is an explanatory diagram showing the position of the print head and the position of the belt holes. , FIG. 4 is a sensor, FIG. 5 is a configuration diagram of an embodiment of the present invention,
FIG. 6 is an explanatory diagram of the operating state. In the figure, 10 is a bell), 11 is an external device, 12 is a microcomputer, 13 is a control program storage unit,
14 is a space control section, 15 is a driver, and 16 is a sensor output detection circuit. Patent Applicant Fujitsu Limited Representative Patent Attorney Akira Yamatani Sakae 1st Ward $2 (21 Shinobu 4 Figure sy"'i-": 4 History RD

Claims (1)

[Claims] In a printing device equipped with a print head and a print head drive belt, multiple types of position identifiers are provided on the print head drive belt to identify that the print head is in a plurality of predetermined positions, and these position identifiers are detected. A print head position detection method characterized in that a common sensor is provided, and the print head position is detected based on the output of the common sensor.