JPS59106981A - Paper feed control apparatus of printer - Google Patents

Abstract

PURPOSE:To remove the loading defect of paper, by controlling a stepping motor so as to lower the driving speed thereof as the numbers of paper feed lines become much more in a continuous transfer SL mode. CONSTITUTION:A static memory apparatus ROM preliminarily stores a high speed code corresponding to a driving speed generating no loading defect of paper 1 by paper feed of the N1 line and below of a SL mode, a medium speed code corresponding to the N1 line and a low speed code corresponding to an N2 line in separate area. The above mentioned N1 and N2 are integers specified in order to judge the numbers of feed lines in the SL mode and, for example, N1 is set so as to form a formula N1<Na with respect to the numbers of lines Na between L1-L2 while N2 is set so as to form a formula Na<N2<Nb with respect to the numbers of lins Nb between Na and L3-L4 and, that is, a formula N1<N2 is formed. In a SL mode for continuously transferring the paper 1 over a plurality of lines, the numbers of lines thereof are judged by a CPU and, when the numbers of lins are many, a paper feed speed is lowered by the control of the CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feed control device for a printer that transports printed sheets in one direction and sequentially stacks them on a stacking table.

In general, in a high-speed line printer, as shown in FIG. 1, a sheet of paper 1 that is engaged with a sprocket 2 that is interlocked with a stepping motor STM and transported in the direction of arrow F is transferred to a roller that is interlocked with a motor 8 in the paper feeding direction. Then, they are held by rotatable support rollers 5 and stacked one after another on a loading table 6 while being bent along perforations 1α (FIG. 2).

At this time, the paper can be transported in two modes, as shown in Figure 2, in which the paper is transported intermittently while printing is being performed (sp mode), and in a mode in which the paper is transported continuously over multiple lines without printing. There are two modes: a mode in which the print data is transferred to the printer (SL mode), and one of these modes is selected based on the print command from the host computer.
Conventionally, the stepping motor STM was driven at the same speed regardless of the number of lines to be fed in the SL mode. The moving speed of the paper becomes extremely high, and the paper falls onto the stacking table 6 before it is sufficiently bent, resulting in paper stacking failure.

An object of the present invention is to eliminate the above-described drawbacks of the conventional method by controlling the driving speed of the stepping motor STM to decrease as the number of paper feed lines increases in the SL mode.

Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG.
A well-known central processing unit with input/output functions, Ilo is the CPU
Ink for input and output? -7ACE, ROM is a static storage device, and each control program of the CPU and setting speed information of the stepping motor STM, which will be described later, are stored separately at different addresses. RAM is a readable and writable dynamic storage device, DR is a stepping motor S
This is a drive circuit for the stepping motor STM, and distributes drive pulses given from the CPU via the stepper 10 to each excitation coil of the stepping motor STM.

PFC is a paper feed command from the host computer.
Contains information to indicate the number of lines to which the paper should be transferred next.

The ROM stores paper by feeding the paper below N1 lines in SL mode.
a "high speed" code corresponding to a driving speed that does not cause a loading defect, and a "medium speed" code corresponding to a driving speed that does not cause a loading defect of paper 1 when feeding N1 lines in the SL mode. A "low speed" code corresponding to a driving speed at which paper 1 does not cause stacking failure when paper is fed by N2 lines in the SL mode is stored in advance in each separate area.

Here, Nl and N2 are integers specified for determining the number of feed lines in the SL mode, and N1 is, for example, L
The number of lines Nα between 1 and L2 is set to be N1 times Nα, and N2 is set so that N a (N 2 (NA) That is, Nl<N2.

In addition, to explain the definition of SP mode and SL mode in the present invention, SP mode is the stepping motor ST.
This corresponds to a paper feeding line interval so short that M cannot reach its steady speed, which is approximately 5 lines experimentally.

Therefore, in the present invention, especially continuous feeding of 5 lines or less is
mode, and continuous feeding of 6 lines or more is called SL mode, and therefore is 6(Nl(N2).

Figure 4 shows C called in connection with paper feed specification PFC.
This is a control flow of PU.

In the flow, when a paper feed command PFC is generated, if the command is in SL mode, the number of paper feed lines N by that command is determined, and if it is N less than N1, the "high speed" code is set.
1 <N<N 2, a "low speed" code is read from the ROM according to each condition, and the period of the drive pulse to be applied to the drive circuit DR of the stepping motor STM is controlled via step 10.

The case where the printing shown in FIG. 2 is performed using the above configuration will be explained.

When Ll of paper 1 faces the printing section, when the host computer issues a paper feed command Nα for the number of digits up to L2, which is the next print line, the CPU determines this number Nα,
The code in the ROM is read so that the stepping motor STM is driven at "medium speed", so that when the paper 1 passes through the printing section between L1 and L2, it is driven at "medium speed". ” will be sent. When L2 of paper 1 faces the printing unit, the host computer issues an sp-mode paper feed command while transporting the next line up to L8, where the print line is interrupted. Intermittent drive for each line printed. When L8 of paper 1 faces the printing unit, the host computer issues a paper feed command (SL
mode) is issued. At this time, since Nh>N2, the CPU sets the stepping motor STM to "low speed", so that the paper 1 is fed in the SL mode "low speed" between L8 and L4.

As described above, according to the present invention, in a printer configured to transport printed sheets in one direction and stack them one after another, in the SL mode in which sheets are continuously transported for multiple lines, the number of lines is determined by the CPU. However, when the number of lines is large, the paper feeding speed is reduced under the control of the CPU, thereby preventing paper stacking failure and improving the efficiency of printing work.

Incidentally, in the above embodiment, a stepping motor is used as a driving means for the sprocket 2, but for example, a servo motor or other driving means may be used.

Further, in the above embodiment, the paper 1 is bent by the roller 4 and the support roller 5, but in a printer that is not very high speed, these rollers are not used and the paper 1 is bent by its own weight. You may also do so.

In addition, in the above embodiment, the paper feeding speed based on the judgment of the number of lines to be fed in the SL mode is set to three levels: "high", "medium", and "low", but by dividing the judgment of the number of lines to be fed in more detail, If the paper feeding speed is controlled, it may be controlled in multiple stages.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the paper loading device of the printer, and Fig. 2 is a schematic diagram of the paper loading device of the printer.
FIG. 8 is a block diagram of the control circuit, and FIG. 4 is a 70-chart of the control state. l... Paper, 2... Paper feeding means, STM... Drive means (stepping motor), 8, 4, 5, 6... Loading means, CPU... Control circuit, ÷÷ 綞=ridge Name of applicant: Tokyo Heavy Equipment Industry Co., Ltd.

Claims (1)

[Scope of Claims] Paper feeding means supported on the machine frame so as to engage the paper and transport the paper from the printing section, and connected to the paper feeding means so as to transport the paper in one direction by driving. , a driving means whose driving speed can be adjusted by electrical control; a loading means which is arranged in the machine frame at the front in the direction of paper feeding from the paper feeding means and is capable of sequentially folding and stacking paper; and a printing means. Based on the command, specify one of the first mode that transports paper intermittently or the second mode that transports paper continuously, and the number of lines that should be continuously transported in the second mode. A paper feed control device for a printer, comprising: a control circuit that sets the drive speed of a drive means to be lowered as the number increases.