JPS5939584A - Automatic paper loading control circuit for printer - Google Patents

Abstract

PURPOSE:To reduce the time of loading a printing section with a paper by slowing down the paper carrying speed where the printing paper is hard to carry while speeding it up where it is easy to carry. CONSTITUTION:While the tip of a printing paper 2 reaches a tractor 10 from an automatic load table 4 via a printing section, namely, a photosensitive drum 7 and a guide 8, jumming, wrapping on the photosensitive drum 7 and other troubles are readily caused. In this part, the carrying of the paper 2 is done at a low speed while at a high speed in other part. To achieve this, a means is provided to detect the tip of the paper 2 passing the printing section and the paper is fed at a low speed only for a specified time from the moment of detecting it. The specified time is preferably detected with a one-shot multivibrator.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an automatic sheet loading control circuit in a printing device, and particularly to speeding up automatic sheet loading in a high-speed line printer.

(2) Background of the Technology As printing devices such as line printers become faster, the ratio of paper loading time to output waiting time can no longer be ignored. In other words, even though printing time has been shortened, paper loading still relies on manual labor such as an operator.
Even with automatic paper loading, they were very time consuming compared to the printing speed. Therefore, it has been desired to develop an automatic sheet loading control circuit that can further reduce the time required. (3) Prior art and problems FIG. 1 is a schematic diagram of a sheet conveying section. 1 is a paper hopper,
2 is a printing paper, 3 is a splicing table, 4 is an automatic loading (hereinafter referred to as autoload) table that can be moved up and down, 5 and 9 are transfer guides, 6°8 is a guiding guide, 7 is a photosensitive drum, and 10 is a Tractor presser foot lid, 11 is a tractor,
12 is a fixing device, 13 is a paper pull-in roller, 14 is a stacker, and 26 is a tractor drive motor. Print paper 2
The transportation @ structure is as follows.

The paper 2 is pulled out from the paper hopper 1, passed through the splicing table 3, and the leading edge of the paper 2 comes to the autoload table 4. When the leading edge of the paper 2 reaches the autoload table 4, the autoload table 4 is raised and the feed hole of the paper 2 is coupled to the tractor 11. Furthermore, when the autoload switch (not shown) is pressed, the tractor drive motor 26
begins to rotate and the paper 2 moves through the transfer guides 5 and 9 and the guide guide 6.
8, and is automatically set in the direction of the arrow to the stacker 14. In FIG. This is because the optical drum 17 is rotating in the direction in which the printing paper 2 moves (in the direction of the arrow) when the paper is loaded, so the printing paper 2 does not separate from the photosensitive drum 17 especially in front of the guide 8. This is because there is a possibility that it will be caught in the photosensitive drum 17 as it is. Therefore, the rotation speed of the tractor drive motor 26 is slowed down, and the conveyance speed of the printing paper 1 is slowed down to prevent the printing paper 1 from being omitted onto the photosensitive drum 7.

However, in the conventional paper automatic loading control circuit, the paper transport speed at a location where paper transport is easy is set to the same speed as the above-mentioned location where paper transport is difficult. This method takes a long time to load the paper, but the effect of this can be ignored in high-speed line printers and the like.

(4) Object of the Invention In view of the above-mentioned shortcomings of the conventional art, an object of the present invention is to provide a paper loading control circuit that can shorten the paper loading time without determining the paper loading time at a location where paper transport is difficult. It is in.

(5) Structure of the invention and the purpose of the invention is to
~, a printing unit that prints on the printing paper; a paper feeding unit that conveys the printing paper to the printing unit and loads it; and 3- a detection means that detects that the leading edge of the printing paper has completely passed through the printing unit; This is achieved by providing a paper automatic loading control circuit in a printing device, which is characterized by comprising a transfer control circuit that increases the paper feeding speed by the paper feeding section according to the detection means, from before the detection to after the detection. Ru.

(6) Examples of inventions Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of an automatic sheet loading control circuit according to the present invention.

Figures 1 and 2 are numbered serially, and in both Figures 26 represents the entire tractor drive motor. First, when an autoload switch (not shown) is pressed, a paper autoload signal (indicated by the symbol AUTLD in the figure) is set to "1". This signal is input to the one-shot multivibrator 17. The output of one-shot multivibrator 17 is AUT
The time is set so that the LD signal remains "1" until the leading edge of the paper passes the tractor presser cover 10.

4- On the other hand, the frequency dividing circuit 16 divides the frequency of the reference clock by 1/n. Therefore, the output of the AND element 20 is AUT
1/1 of the reference clock for the time set by the one-shot multivibrator 17 after the LD signal becomes "1".
It will output n clocks. This signal passes through the OR element 21 and is input to the pulse train generator 22 (f).

The pulse train generator 22 is set in advance so that the pulse intervals of the output signal are coarse at first, gradually become denser9, and become constant intervals at a certain point.

Next, the output signal of the pulse train generator 22 is input to the up side of the comparator 23 (indicated by symbol U in the figure).

On the other hand, a pulse train signal generated by a rotary detector 27 attached to a tractor drive motor 26 that drives the tractor 11 is input to the down side of the comparator 23 (indicated by a symbol in the figure). Therefore, the output signal of the comparator 23 is the number of pulses output by the pulse train generator 22.
If the number of pulses is greater than the number of pulses output, it will increase, and if it is the opposite of the above, it will decrease.
004・Repeat the above operation until the number of output pulses and the number of pulses output by the rotary detector 27 are the same.Then, the output signal from the comparator 23 is D/ The signal is converted into an analog signal through the A converter 24, amplified by the amplifier 25, and then applied to the tractor drive motor 26. Therefore, the tractor drive motor 26 maintains rotation at a speed of 17n, which is the reference rotational speed. On the other hand, when the time preset by the one-shot multi-by break 17 has elapsed, the output of the one-shot multi-by break 17 becomes 10". Therefore, the output of the AND element 20 also becomes "0", but instead the output of the AND element 19 comes to output the reference clock.As a result, the period from the autoload table 4 to the tractor presser lid 10 in FIG. The rotation speed of the tractor drive motor 26 is 17 n
Therefore, the transport speed of the printing paper is also 1/n of the reference speed. When the leading edge of the paper passes the tractor presser cover 10, the motor 26fd rotates at the reference speed, so that the transport speed also becomes the reference speed (current transport speed).

Here, the autoload signal AUTLD is reset by setting the time for conveying the paper from the autoload table 4 to the stacker 14 using a one-shot multivibrator (not shown), or by setting the number of pulses of the rotary detector 27. This can be done by detecting the amount of paper movement by counting.

The time required for the leading edge of the paper to reach the tractor presser cover 10 can be set by attaching a paper detector to the tractor presser cover 10 in place of the multivibrator 17, and detecting when the leading edge of the paper has passed and adjusting the speed. A similar effect can be obtained by a control method.

(7) As described in detail, according to the present invention, the paper transport mechanism is slowed down in locations where paper transport is difficult, and the paper transport speed is increased in locations where paper transport is easy, thereby maintaining the same speed as the conventional method. This conveyance mechanism also has the effect of shortening the paper loading time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a paper transport mechanism, and FIG. 2 is a block diagram showing an automatic paper loading control circuit according to a seventh embodiment of the present invention. In the drawing, 2 is a printing paper, 4 is an autoload table, 5 and 9 are transfer guides, 6 and 8 are guide guides, 7 are photosensitive drums, 10 is a tractor presser lid, 11 is a tractor,
16 is a frequency divider, 17 is a one-shot multivibrator, 23 is a comparator, 26 is a tractor drive motor, and 27 is a rotary detector. 8-

Claims (1)

[Claims] 1. A printing unit that faces the loaded printing paper and prints on the printing paper, a paper feeding unit that transports the printing paper to the printing unit and loads it, and a leading edge of the printing paper that A printing device comprising: a detection means for detecting passing through a printing section; and a transfer control circuit that increases the paper feeding speed by the paper feeding section according to the detection means, from before the detection to after the detection. Paper automatic loading 111iJ control circuit 0 2 The printing device according to claim 1, wherein the detection means is a one-shot multivibrator that operates only during the time when the leading edge of the printing paper passes through the printing section. automatic paper loading control circuit in 3. Claim 1, characterized in that the detection means is a paper detector provided at the printing paper outlet of the printing unit.
2. A paper automatic loading control circuit in a printing device according to item 1 or 2.