JPH03216369A - Method for controlling line feed pitch based on thickness of paper - Google Patents

Abstract

PURPOSE:To apply printing to any paper at a regular position by correcting line feed pitch according to the thickness difference of paper by adjusting the distance between a printing head and a platen by a cam to indicate the quantity of rotation to a line feed motor. CONSTITUTION:A printer receives a printing command to feed paper. After the paper is fed to a predetermined position, automatic head gap operation is performed. Thereafter, the operation quantity Ac of a cam is counted and the value thereof is stored in an RAM 51. When the first line of the paper is printed, the cam operation quantity As stored in an EPROM 53 is compared with the present cam operation quantity Ac and, when the cam operation quantity Ac is more than the cam operation quantity As by 20 pulses or more, the present paper is judged to be thin and, when the cam operation quantity Ac is less than the cam operation quantity As by 20 pulses or more, the present paper is judged to be thick. In the case of thick paper, the correction of +0.04mm is necessary in 1/6 inch line feed and, in the case of thin paper, the correction of -0.04mm is necessary in 1/6 inch line feed.

Description

[Detailed Description of the Invention] [Summary] A printer device having an automatic paper thickness adjustment function, which aims to make it possible to print in the correct position on any medium, regarding a line feed amount control method based on the plate thickness. In this method, paper of a specified thickness is fed between a print head and a platen, automatic paper thickness adjustment is performed, and the cam rotation amount As at this time is stored in a memory. When printing on paper, feed the paper between the print head and the platen, perform χ automatic paper thickness adjustment, find the cam rotation amount Ac at this time, and calculate the cam rotation amount As and cam rotation amount Ac. By comparison, the printing paper is cardboard. Is it thin paper? If the paper is neither thick nor thin, it instructs the linefeed motor to rotate by N at the time of line feed, and in the case of thick paper, it instructs the linefeed motor to effectively apply force N+α (α is a positive value). In the case of a thin rabbit, it instructs the linefeed motor to rotate by a substantial GcoN-β (β is a positive real number).

[Industrial application field]

The present invention relates to a line feed amount control method based on sheet thickness, in which a rotation amount command value for a line feed motor is changed in accordance with the thickness of the sheet.

[Conventional technology]

A line feed is performed by driving a line feed pulse motor. When the line feed amount is, for example, 1/6 inch, the rotation amount command value for the line feed pulse motor is set to 60 pulses. Conventionally, when performing a 1/6 line feed, the rotation amount command value was 6, regardless of whether the paper was thick paper or thin paper.
It was supposed to be 0 pulse.

[Problem to be solved by the invention]

However, in the case of standard thickness paper, a 1/6 inch line feed is performed when the line feed pulse motor rotates for 60 pulses, but in the case of thick paper, even if the line feed pulse motor rotates 60 pulses, a 1/6 inch line feed is performed. If a 6-inch line feed is not performed and the paper is thin, the line feed pulse motor rotates 60 pulses and the
A line break of 6 inches or more is performed. The reason why this phenomenon occurs is that when using thick paper, the amount of slip between the paper feed roller and the paper is greater than when using paper of the standard thickness, and when using thin paper, the amount of slip between the paper feed roller and the paper is greater than the amount of slip between the paper of the standard thickness. This is because the paper size is smaller than that of paper.

As described above, conventionally, line feeds are performed uniformly on paper of any thickness, so the line feed amount is small for thick paper and large for thin paper. Therefore, when printing on a sheet of paper on which a frame, item name, etc. have been pre-printed, the lower part of the sheet will not match the pre-printed information.

The present invention was created in view of this point, and it is possible to print at the correct position on any medium by correcting the line feed amount depending on the difference in paper thickness. The purpose is to provide a method for controlling the amount of line feeds.

(Method for Solving the Problem) FIG. 1 is a diagram explaining the principle of the present invention. The printer device to which the present invention is applied has an automatic paper thickness adjustment function that uses a cam to adjust the distance between the print head and the platen to keep the distance between the paper on the platen and the print head constant.

Automatic paper thickness adjustment is performed by feeding paper of a specified thickness between the print head and the platen in advance, and the cam rotation amount As at this time is stored in a memory.

When printing on paper, feed the paper between the print head and platen, perform automatic paper thickness adjustment, calculate the cam rotation amount Ac at this time, and calculate the cam rotation amount AS and cam rotation amount Ac.
Compare and check if the printing paper is thick paper. Determine whether the paper is thin or not. If the paper is neither thick nor thin, the line feed motor is instructed to rotate by N when starting a line, and if it is thick paper, the line feed motor is essentially instructed to rotate by N+α (α is a positive real number) when starting a line. In the case of thin paper, the line feed motor is effectively N - β (β is a positive real number).
Indicates the amount of rotation.

[Embodiment] FIG. 2 is a perspective view of an example of a printer device that can adjust the head gap, and FIG. 3 is a sectional view showing details of a guide section above a carrier. A guide rod 2 is installed parallel to the platen L, and an L-shaped guide rail 3
is attached to Guide Rondo 2 in parallel. The carrier 4 reciprocates along the guides 2 and 3. The platen 1 includes a paper feed roller 1o that is pivoted to the frame of the device.
It is swingably supported on a shaft 11 by an arm 12, and is mounted so as to be able to move toward and away from the print head. Rollers 13 are pivotally attached to both ends of the platen 1, and the platen 1, which is urged downward by its own weight or a spring, is supported by the roller l3 coming into contact with the cam 6. The cam 6 is fixed to a camshaft 14, and the camshaft l4 is mounted at a fixed position on a frame (not shown) and connected to a pulse motor 17 via gears 15, 16. Therefore,
When the cam 6 is rotated by the pulse motor 17, the platen 1 is pushed by the cam 6 and moves up and down. The contour curve of the cam 6 is a curve in which the amount of elevation of the platen 1 and the rotation angle of the cam 6 are proportional. The carrier 4 is slidably and rotatably supported by a guide rod 2 attached to a fixed position on the frame, and is supported by a guide rod 20 and a slider 21 at its upper part.
It holds the rail 3. The guide structure on the upper part of the carrier is shown in FIG. 3, in which the guide rail 3 is held between a roller 20 pivoted on the carrier 4 and a sliding body 21 urged toward the roller 20 by a panel 22. , allows the carrier 4 to move along the guide rod 2, and restricts rotation of the carrier 4 around the guide rod 2. In FIG. 3, 23 is a sleeve that holds the sliding body 21 in a manner that it can be freely retracted and retracted, and 24 is a spring retainer.

The print head 5 has an arm 4 extending horizontally below the carrier 4.
Therefore, when the carrier 4 rotates around the guide rod 2, the print head 5 moves toward and away from the platen 1. The rotation of the carrier 4 around the guide iron 2 is regulated by a roller 20 and a sliding body 21 biased by a spring 22. In other words, the print head 5 is urged toward the platen 1 by the spring 22, and its advancing end position is regulated by the rollers 20.

A detection piece 30 is fixed to the upper part of the carrier 4,
A sensor 7 having a pair of opposing light emitting device 31 and light receiving device 32 is arranged at a position slightly apart from the position of the tip of the detection piece 30 in a steady state. Note that printer devices having an auto head gap adjustment function are disclosed in, for example, Japanese Patent Application Laid-Open No. 199969/1983 and Japanese Patent Laid-Open No. 1378/1989.
This is disclosed in detail in Japanese Patent No. 70.

FIG. 4 is a diagram showing an example of a paper conveyance system of a printer. When the line feed pulse motor rotates, the platen 1, paper feed roller 69, paper feed rollers 70 and 71, and discharge port roller 73 rotate. Note that the tractor 74 is used when producing continuous sheets.

Automatic paper feeding of the cut sheet 40 is performed as follows.

■ The booster (not shown) rises.

■ The paper feed roller 69 rotates and the paper 40 is taken out from the hopper.

■ The leading edge of the paper 40 is fed to a predetermined position by the rotation of the paper feed rollers 70 and 71, and is then moved a predetermined distance (
until the first line of paper is under the print head 5)
send.

Paper is ejected as follows.

■ Platen 1, paper feed roller 72, discharge port roller 73
The paper 40 is conveyed by the rotation of.

(2) After the rear end of the paper 40 passes a predetermined position, the paper is further fed a predetermined distance and discharged to a stacker (not shown).

FIG. 5 is a diagram showing an example of the electric circuit of the printer. Microprocessor 50 executes programs stored in control memory 52. The RAM 51 has a buffer for temporarily holding data, a work area, and the like. E2
The PROM 53 stores data that is desired to be saved. The interface control circuit 54 controls data transfer with the computer of the main system. The microprocessor 51 connects to the console via the output port 57.
Data can be sent to the panel 55 and the driver and mechanism section 56, and data from the console panel 55 and the driver and mechanism section 56 can be read via the input/output port 58. Bidirectional driver/receiver 60 drives address signals, and bidirectional driver/receivers 61 and 62 drive data signals. Address decoder 59 decodes address signals. Data is written to/read from a register etc. determined by this decoding result. Inside the dryer and mechanism section 56, there are a pulse motor for adjusting the auto/henod/gannob and a motor for moving the carrier. There is a pulse motor for line feed, etc.

FIG. 6 is a diagram illustrating the line feed processing of the present invention.

When the printer device is shipped from the factory, it undergoes adjustment tests and
The program TP is started, a standard medium (paper of standard thickness) is fed, and auto-hend-ganop processing is performed. Auto head gear knob processing means processing to maintain the distance between the tip of the print head and the paper surface to a constant value when paper is inserted. After performing auto-henod-ganop processing, the operating amount As of the cam 6 at that time (rotation angle with respect to the lowest position of the platen) is stored in the E2FROM 53. The printer device is shipped in this state.

The printer device at the user's destination performs line feed processing as described below. Upon receiving the print command, the printer device feeds paper. After feeding the paper to a predetermined position, an auto head gap operation is performed, and then the cam operation amount Ac is counted. This value is stored in RAM51. When printing the first line of paper, E. The cam movement amount As stored in the 2PROM 53 is compared with the current cam movement amount Ac. If the cam operation amount Ac is 20 pulses or more larger than the cam operation amount As, the current paper is determined to be thin paper,
If the cam operation amount Ac is smaller than the cam operation amount As by 20 pulses or more, the current paper is determined to be thick paper.

For thick paper, 1/6 inch (60 pulses) line break +0
．． In the case of thin paper, a 1/6 inch (60 pulses) line feed requires a correction of -0.04 mm. The line feed resolution is 0.07mm per pulse (
1/360 inch), one pulse correction is performed every 105 pulses.

For example, in the case of thin paper, the first rotation amount command value for the line feed pulse motor is 60 pulses, and the second rotation amount command value is 59 pulses. The third rotation amount command value is 60
pulse, the fourth rotation amount command value is 59 pulses. The fifth rotation amount command value is 60 pulses, and the sixth rotation amount command value is 59 pulses. The seventh rotation amount command value may be set to 59 pulses. In addition, in the case of thick paper, the line feed pulse
The first rotation amount command value for the motor is 60 pulses, the second rotation amount command value is 61 pulses, and the third rotation amount command value is 60 pulses. The fourth rotation amount command value is 61 pulses. The fifth rotation amount command value is 60 pulses. The 6th rotation amount command value is 61 pulses. The seventh rotation amount command value may be set to 61 pulses. If the paper is neither thin nor thick paper, the rotation amount command value for the line feed pulse motor is always set to 60 pulses.

After the first line of the paper is positioned at the print hand position, printing of the first line is performed, and then a line feed is performed, and the second line feed is performed as described above. That is, in the case of thin paper, the rotation amount command value is set to 59 pulses, in the case of thick paper, the rotation amount command value is set to 61 pulses, and in the case of neither thin paper nor thick paper, the rotation amount command value is set to 60 pulses. .

〔Effect of the invention〕

As is clear from the above description, according to the present invention, printing can be performed at regular line positions regardless of the thickness of the paper. In the above description, a printer device in which a platen moves up and down by a cam is used as an example, but it goes without saying that the present invention can also be applied to a printer device in which a print head moves up and down by a cam.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a diagram showing an example of a printer device that can adjust the head gap, Fig. 3 is a diagram showing details of the guide section above the carrier, and Fig. 4 is a diagram of the printer. FIG. 5 is a diagram showing an example of a printer's electric circuit, and FIG. 6 is a diagram illustrating line feed processing of the present invention. 1...Platen, 2...Guide Rondo, 3...
L-shaped guide rail, 4...Carrier, 5...Print head, 6...Cam,...7...Photo sensor,
40...Paper, 50...Microprocessor, 51
...RAM, 52...Control memory, 53...E2P
ROM, 54...Interface system JB times u, 55
...Console panel, 56...Driver & mechanism section, 57...Output port, 58...Input port, 6 9...Paper feed roller, 70 or 7 2...Paper feed roller, 73...Discharge port-ra, 7 4...Tractor.

Claims (1)

[Claims] Line feed amount control based on the plate thickness in a printer device having an automatic paper thickness adjustment function that uses a cam to adjust the distance between the print head and the platen to keep the distance between the paper on the platen and the print head constant. In this method, paper of a specified thickness is fed between the print head and the platen, automatic plate thickness adjustment is performed, the cam rotation amount As at this time is stored in memory, and printing is performed on the paper. , feed the paper between the print head and the platen, perform automatic plate thickness adjustment, calculate the cam rotation amount Ac at this time, compare the cam rotation amount As with the cam rotation amount Ac, and determine whether the printing paper is thick paper. If the paper is neither thick nor thin, it instructs the linefeed motor to rotate by N when starting a line, and if it is thick paper, it instructs the linefeed motor to rotate an amount of N when starting a line. It is characterized by instructing the amount of rotation of N+α (α is a positive real number), and in the case of thin paper, instructing the amount of rotation of N−β (where β is a positive real number) to the line feed motor when starting a line. A method for controlling the amount of line feeds depending on the thickness of the plate.