JPS6096479A - Printer - Google Patents

Abstract

PURPOSE:To always perform an optimal printing by reading data indicating the thickness of a printing paper provided thereon to control the interval between the print head and the platen to the optimum value. CONSTITUTION:When a printing paper 19 is fed and a thickness data 22 recorded on the paper 19 passes in front of a photocoupler 17, the photocoupler 17 detects and outputs the thickness data to a CPU, which reads out the interval data for the thickness from an RAM25 based on the thickness data 22. Then, the CPU outputs a drive control signal for optimizing the interval D between the print head 4 and the platen 2 to a stepping motor 9 through a driving circuit 26 based on the interval data read out. In response to the control signal, the stepping motor 9 turns a guide shaft 6 to move the carriage 3 forward or backward thereby setting the interval D between the print head 4 and the platen 2 at the optimum value for the printing operation.

Description

Detailed Description of the Invention Technical Field The present invention relates to a printing device capable of printing on printing paper on a platen by reciprocating a carriage having a print head along the platen. The present invention relates to a printing device in which the distance between a platen and a print head can be changed as appropriate.

Conventional technology: Conventionally, printing devices print by changing the thickness of the printing paper or by overlapping multiple sheets of printing paper at the same time so that the printing stroke of the printing element always has the optimum stroke no matter what kind of printing paper it is. It was necessary to change the distance between the print head and the printing paper, that is, the distance between the print head and the platen, depending on the thickness of the paper in the case.

In the past, there have been various detection devices for detecting paper thickness in order to change this interval appropriately, but all of them have been mechanically detected. For example, a pressure-sensitive member is brought into contact with the printing paper, and the thickness of the printing paper is detected based on the movement of the pressure-sensitive member in accordance with the paper thickness of the printing paper.

However, this mechanical detection method has a limit in detecting the thickness of printing paper of about 0.05 mm to 0.06 mm, and in reality, it has not been possible to accurately detect it. Therefore, the four printing strokes of the printing elements of the print head were not set to the optimum strokes, and printing operations were not performed in the optimum condition.

Purpose This invention was made in order to solve the above-mentioned problems, and its purpose is to accurately detect the paper thickness of printing paper, and to optimize the distance between the print head and the platen based on this detection result. To provide a printing device that can always perform optimal printing.

Structure of the Invention In order to achieve the above-mentioned objects, the structure of the present invention provides a driving device for driving the print head toward and away from the platen in the printing device, and also provides a driving device for driving the print head toward and away from the platen. A reading device is provided for reading data representing paper thickness, and the driving device is configured to control the drive device based on an output signal from the reading device so that the distance between the platen and the print head is optimal for the paper thickness of the printing paper. It is equipped with a control means for controlling.

EXAMPLE An example embodying the present invention will be described below with reference to the drawings.

In FIG. 1, a frame 1 of the printing device includes a platen 2.
are arranged and fixed, and a printing surface 2a is formed on the front surface thereof. A carriage 3 is arranged in front of the print surface 2a, and a print head 4 containing a print element (not shown) is placed on the upper surface of the carriage 3.

The eccentric cam 5 rotatably fitted to the lower boss portion 3a of the carriage 3 is unrotatable with respect to the guide shaft 6 rotatably supported by the frame 1, and is moved by one movement in the axial direction. Possibly installed. A gear 7 is attached to one end of the guide shaft 6.
A first step motor 9 serving as a drive device is drivingly connected via a motor 8, and the guide shaft 6 is rotationally controlled by the motor 9 within a range to be described later.

A support body 10 is fixed to the rear side of the carriage 3, and a support plate 12 fixed to the frame 1 is rotatably engaged with a fitting recess 11 formed on the rear side.

(When the guide shaft 6 rotates, the carriage 3 tries to rotate around the guide shaft 6 via the eccentric cam 5, but since the support body 10 is engaged with the support plate 12, , it is moved back and forth in the direction of the arrow, as shown in FIG.

As a result, the distance between the print head 4 and the platen 2 can be changed as appropriate by driving and controlling the first step 9.

A wire 13 for moving the kittredge 3 in the left-right direction along the guide shaft 6 is connected to a wire 4 disposed outside the frame 1.
The pulley 14 is pulled out 11), and one part of the pulley 14 is fixed to a wire stopper 15 attached to the carriage 3.

The second step motor 16 is drivingly connected to the wire 13 and moves the carriage 3 in the left-right direction along the guide shaft 6 via the wire 13.

Below the print head 4, a cover 17 consisting of a light-emitting element and a light-receiving element as a reading device is fixedly attached to the carriage 3 via a support arm 18. It is designed to read paper thickness data.

The printing paper 19 is guided upward on the printing surface 2a of the platen 2 by a pair of feed rollers 2o arranged below the platen 2 and a pair of tension rollers 21 arranged above the platen 2. be done.

Then, characters are printed on the print paper 19 by the print head 4 at the front.

Further, as shown in FIG. 3, on the surface of the printing paper 19, paper thickness data 22 consisting of a bar code indicating the paper thickness of the printing paper 19 is recorded in the upper left corner thereof.
It is read out at 7.

Next, an explanation will be given of the electric circuit of the printing device constructed as shown in the figure.

In Fig. 3, the central processing unit (hereinafter referred to as
CI) 23 includes a read-only memory (hereinafter referred to as ROM) 24 and a readable and replaceable memory (hereinafter referred to as RAM) 25, and the ROM
It is operated according to a control program stored in the printer 24, and paper thickness data 22 recorded on the printing paper 19 is inputted via the photocoupler 17.

The RAM 25 stores spacing data that indicates the optimum spacing between the print head 4 and the platen 2 for various paper thicknesses of the printing paper 19, and the CPIJ 23
The paper thickness of the printing paper 19 is determined based on the paper thickness data 22 inputted through the printer 17, and the CPU 23 reads out interval data corresponding to the paper thickness.

Further, the CPU 23 sends a drive control signal via the drive circuit 26 to drive and control the first step motor 9 based on the read spacing data to optimize the spacing between the print head 4 and the platen 2. output to the first step motor 9. Further, the CPU 23 outputs a drive signal to the second step 16 via the drive circuit 27 to drive and control the second step motor 16 to move the carriage 3 along the guide shaft 6.

Next, the operation of the printing device configured as described above will be explained.

First, when one printing paper shown in FIG. 3 is set in the printing device and a start switch (not shown) is turned on, the photocoupler 17 will be able to read the paper thickness data 22 while recording it in the printing [19]. The carriage 3 is moved by a second step motor 16 to a position not shown in FIG. Next, the printing paper 19 is fed and pulled by a roller 2o,
Paper thickness data 2 sent out at 21 and recorded on the same paper 19
2 passes in front of the photocoupler 17.

At this time, the photocoupler 17 detects (reads) paper thickness data and outputs it to the CPU 23. Cl3() 23 determines the paper thickness of the printing paper 19 based on the paper 19 data 22, and reads the interval data for the same paper thickness from the RAM 25.

Next, the CPU 23 drives and controls the first step motor 9 based on the read interval data to drive the print head 4.
Drive 9 to optimize the distance between the platen 2 and the platen 2
A one-way open signal is output to the first step motor 9 via the drive circuit 26.

The first step motor 9 is driven in response to this control signal to move the guide shaft 6 l! Jl! Make it till. Based on the rotation of the guide shaft 6, the carriage 3 moves forward or backward to set the distance between the print head 4 and the platen 2 to the optimum distance for the printing operation. Therefore, the print element of the print head 4 has its print stroke 0 set to the optimum stroke L1, allowing the printing operation to be performed in an optimum state.

In this embodiment, the paper thickness of the i11 printing paper 19 has been explained, but when multiple sheets of printing paper are overlapped and printed at the same time, the print head and platen may be changed depending on the paper thickness of the overlapped state. to control the spacing to the optimum spacing;
Of course, it is also possible. In this case, the first sheet of multiple sheets of the same printing paper has a third button that indicates the paper thickness when the paper is folded together.
Paper thickness data consisting of a barcode as shown in the figure will be recorded.

Further, in this embodiment, the paper thickness data is constituted by a bar code, but for example, a numerical value indicating the paper thickness may be used instead of the bar code, and the paper thickness of the paper may be determined by pattern recognition.

Effects As detailed above, the present invention provides a printing device with a drive device for driving the print head toward and away from the platen, and also provides data representing the paper thickness of the printing paper provided on the printing paper. A reading device is provided to read the image, and the driving device is controlled based on the output signal from the reading device so that the distance between the platen and the print head is optimal for the paper thickness of the printing paper. By installing a control means for this purpose, the paper thickness of the printing paper can be accurately detected, and based on this detection result, the distance between the print head and the platen can be set to the optimum distance to always perform optimal printing. It has the effect that it can.

[Brief explanation of drawings]

FIG. 1 is a plan view of the main parts of a printing device embodying this invention.
Figure m2 is a trrl side view of the main parts, Figure 3 is a front view of the printing paper, and Figure 4 is an electrical block circuit diagram at the printing position '4A (
There is. In the figure, 1 is a frame l1, 2 is a platen, 3 is a carriage, 4 is a print head, 9 is a first stellar/shield as a driving device, 17 is a cover 1 and a cover as a reading device, 19 is the printing paper, 22 is the paper thickness data, 23 is the control 9
11 is a central processing unit (CPLJ) as a means; 25 is a readable and replaceable memory IAM; and D is an interval. Patent Applicant: Kon, representative of Brother Industries, Ltd. Patent Attorney: Fugenobu Onda

Claims (1)

[Claims] One platen (2) movable along the platen (2).
□ A print head (4) for printing characters, etc. on a print paper (19) that is capable of moving toward and away from the platen (2);
a drive device (9) for driving in the separating direction; and (1) printing paper provided on the printing paper (19).
a reading device (17) for reading data (22) representing the paper thickness; and a distance (D) between the platen (2) and the print head (4).
control means (23) for controlling the drive device (9) based on the output signal from the reading device (17) so that the thickness of the printing paper (19) is optimized; A printing@place characterized by comprising: