JPS63251261A - Printer - Google Patents

Abstract

PURPOSE:To improve sheet feed accuracy immediately after setting of sheet, by detecting a signal fed from a sheet detecting section then recognizing change from no sheet condition to sheet set condition and making that information holdable/cancelable while furthermore providing fine sheet feed control. CONSTITUTION:Driving of a thermal head 1, a traction solenoid 4, a carriage motor 6 and a line feed motor 8 and detection of signals fed from a home position sensor 11 and a sheet sensor 12 are controlled by means of a controller 14. A sheet detection mechanism detects whether there is a sheet 10 in printing section, and when change from fo sheet condition to sheet set condition is detected, setting of a new sheet is recognized. When a sheet is set newly, fine sheet feed mode is made effective and executed prior to printing operation or line feed operation only in this case. Consequently, the position of the line feed motor is set to control position when backlash of sheet feed mechanism section is removed and the sheet feed mechanism is manually set again.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer, and particularly to a printer suitable for improving printing position accuracy in the paper feeding direction.

[Conventional technology]

As described in Japanese Utility Model Application Publication No. 60-41255, the conventional apparatus is of a type in which minute paper feeding is performed by operating a switch. But according to this method.

No consideration was given to operability, as a new switch had to be provided or the user had to operate the switch.

[Problem that the invention seeks to solve]

The object of the present invention is to set paper in a printer.

If you start printing from that position, especially if you set the paper manually, backlash will occur in the paper feed mechanism, and the electric motor control position and physical motor in open loop control such as pulse motors will The purpose is to correct the paper feeding error immediately after paper is set, since a misalignment with the paper position occurs.

[Means for solving problems]

The above purpose is to detect the signal from the paper detection surface, to recognize that the state has changed from paper out to paper present, to retain and release this information, and to control minute paper feed operations. This can be achieved by having the following.

[Effect]

The paper detection mechanism section detects whether or not there is paper in the printer printing section, and when detecting the presence of paper from the absence of paper, it recognizes that paper has been newly set. When paper is newly set.

A minute paper feed mode is enabled, and only when the mode is enabled, a minute paper feed operation is executed before a printing operation or a feed feed operation is executed.

Note that after the minute paper feed operation is executed, the minute paper feed mode is canceled until the mode is enabled.

Normal printing or reversing operations are performed.

The above method can be easily implemented in a printer equipped with a microprocessor.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 is a main configuration diagram of a thermal transfer printer.

Thermal head 1. Ink ribbon 2. ribbon cassette 3
．． The traction solenoid 4 is mounted on a carriage 5 and is moved in the left-right direction via a timing belt 7 by a carriage motor 6 drive. The ink ribbon 2 is wound up and stored in the ribbon cassette 3 only when the carriage moves from left to right by a gear mechanism in the carriage 5 and a drive source of the timing belt 7.

The printing operation is performed by driving the traction solenoid 4.
Thermal head 1. The ink ribbon 2 is pressed against the recording paper 10, and printing is performed while the carriage 5 is moved from left to right. Line feed motor 8 rotates platen roller 9 via timing belt 7 and feeds recording paper 10 . Paper can also be fed in the same way by turning the platen knob 13 by hand. Thermal head 1. Drive of traction solenoid 4, carriage motor 6, line feed motor 8 and home position sensor 119 paper sensor 12
The signal detection is controlled by the controller 14.

FIG. 2 shows an example of a minute paper feeding operation.

The line feed motor 8 is controlled by the CPU in the controller 14.
By control, it can be driven arbitrarily in the paper feeding direction and the reverse paper feeding direction using signals φ1 to φ4. In this embodiment, the line feed motor 8 uses a pulse motor and is driven by a two-phase excitation force type, and the direction of φ1→φ2→φ3→φ4 is the paper feeding direction. Further, the fine paper feeding pitch was set to 10 pitches. a shows the stop control phase of the line feed motor 8 before the minute paper feeding operation. The minute paper feed operation is 10 pitches in the reverse paper feed direction (
B section) After driving, 10 pitches in the paper feeding direction (C section)
Driven. Therefore, in terms of control, the minute paper feed operation is
Since the sheet is returned to the same position, the backlash of the sheet feeding mechanism can be corrected without any influence on control caused by the execution of the operation.

FIG. 3 schematically shows a flowchart of the CPU control software in the controller 14. As shown in FIG. When the printer is turned on, the CPU program starts initial processing 15.
is executed, and the process moves to main processing 16. Main processing 16
Here, the status of the entire printer is managed, and data reception from an external host is also performed here. Paper presence/absence management is performed within the main processing 16, and is shown in 1 in Fig. 3.
The logics 6-1 to 16-4 are the logics for determining whether or not to perform minute paper feeding. The condition for the minute drive request to be satisfied is when paper is set and the previous paper presence/absence information indicates no paper, that is, when the presence of paper can be detected for the first time from no paper. Therefore, when paper is newly set, a minute drive request 16-3 is generated. When a printing or line feed request occurs from the host, it is checked whether there is a minute drive request (19)L, and only when the above request is made, a minute paper feed operation is executed (20), followed by a printing operation (23) or a line feed operation. Execute (24). still,
After executing the minute drive process (2o), the minute drive request is canceled (2o).
1), the minute drive process (20) is not performed from the second line onward, and only the normal operation (23, 24) is performed.

20-1 and 20-2 show an example of minute drive processing. First, the line feed motor 8 is driven by an X pitch (20-1) L in a direction opposite to the paper feeding direction.

Next, X pitch drive (20-2) is performed in the paper feeding direction.

The method described above makes it possible to eliminate backlash in the paper feeding mechanism. Furthermore, if the line feed motor 8 is operated with open loop control such as pulse motor, setting the paper manually using the platen knob will cause a discrepancy between the line feed motor position managed by the CPU and the actual motor position. , the line feed motor position can be aligned with the control position. Therefore, it is desirable that the number of pitches X to be driven in the minute drive process be the minimum number of pinches necessary for eliminating backlash and for line feed motor control positioning.

〔Effect of the invention〕

When setting paper, it is often necessary to manually feed the paper and make fine adjustments to set the paper in the desired print position. According to the present invention, since the paper is automatically slightly fed before printing the first line after setting the paper or performing line feed, it is effective to improve the accuracy of the initial paper feed after setting the paper.

[Brief explanation of drawings]

FIG. 1 is a main configuration diagram of a thermal transfer printer according to an embodiment of the present invention. FIG. 2 shows an example of a minute paper feeding operation. FIG. 3 schematically shows a part of a flowchart of a microprocessor control program for the controller.

Claims (1)

[Claims] 1. In a printer that has a print head, a paper feed mechanism, and a paper detection mechanism that detects the presence or absence of paper, the above operation is started only in the case of the first line printing operation or change operation after detecting paper from a paper-out state. A printer characterized in that a paper feed motor is driven at a minute pitch immediately before the paper feed.