JPH02220876A - Page printer - Google Patents

Abstract

PURPOSE:To improve operability by detecting the position of a sheet guide by a potentiometer, converting it to number of dots corresponding to a printing density and shifting a print starting position. CONSTITUTION:Since a sheet guide 21 moves symmetrically to the center of a sheet cassette 22, the width of a sheet can be detected only at the position of one guide 21. The guide 21 is connected to a potentiometer VR1 on an engine control board 23 through a position detecting bar 24. If its position is altered, the resistance value of the potentiometer VR1 is varied and detected. The resistance value of the potentiometer VR1 is impedance-converted by an IC1, and converted to a digital signal by an A/D converter of an IC2. If the resistance value of the potentiometer VR1 is so set to the moving range of the guide 21 as to vary from 0 to maximum value, when the 1C2 of a 8-bit A/D converter is employed, 256 digital outputs are obtained. That is, the position of the guide 21 can be detected at a pitch equally divided into 256 at the maximum moving distance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a page printer that uses cut paper.

(Prior Art) Conventionally, in page printers such as laser printers and LED printers that print cut sheets set in paper cassettes, the printing start position in the horizontal direction is the same even if the paper size is different. As shown in FIG. 3, paper running is generally based on one side.

And A5.85. In order to prevent paper 3 of various sizes such as A4.84 from traveling in an inclined manner, a plurality of paper feed rollers 1 for feeding paper from a paper cassette are provided, or a plurality of tensile springs for pushing up the paper cassette are provided. Therefore, as the number of paper feed rollers 1 or tensile springs increases, the paper running mechanism becomes more complicated.

Also, in recent low-priced page printers, the fourth
As shown in the figure, the paper feed roller 2 is placed in the center of the paper path.
A simple mechanism with individual arrangement is provided.

In this case, paper travel is based on the center, and paper 3 of various sizes are fed only by the paper feed roller 2 located at the center.

When paper is run based on the center as described above, the paper feed roller 2 is set so that it is always located at the center even if the paper size is different, but the printing start position in the horizontal direction is set for each paper 3. It needs to change.

For this reason, as shown in FIG. 5, the paper cassette 4 is provided with a protrusion 5 for recognizing the paper size, and the printer is provided with a microswitch 6 at a position corresponding to the protrusion 5. There is.

In this case, when the cassette is loaded, the protrusion 5 presses the microswitch 6, and the type of cassette is detected.

In this case, for example, if three microswitches 6 are used, three corresponding protrusions are provided on the cassette side, and the protrusions are selected depending on the paper size, the correct paper size can be recognized.

This is how the printer recognizes the paper size and
Determine the print start position.

(Means for solving the problem) However, in the above conventional page printer,
When using standard size paper such as 4.84, you can determine the printing start position by recognizing the paper size, but when printing on envelopes or non-standard size paper by manual insertion. In this case, it is not possible to position the printing start on the printer side.

Therefore, when printing such non-standard size paper by hand, the operator must enter in advance the print start position of the non-standard size paper into the host computer, which is determined relative to the standard size paper. There is a need.

The above input method will be explained with reference to FIG.

In the figure, 51 is standard size paper with paper width A (for example, A4)
, and 52 is a sheet of non-standard size with a sheet width B, such as an envelope.

Then, when using the standard size paper 51 of paper width A as a reference,
The printing start position of the envelope 52 with paper width B is (A-R)/
Move 2 distances to the right.

Therefore, the operator must input the coordinates into the host computer and shift the coordinates by the number of dots or character pitches corresponding to the resolution.

As described above, the present invention allows the printer to automatically determine the print start value in the horizontal direction without inputting the print start position to the host computer in advance. The purpose of the present invention is to provide a page printer that can calculate and print data, and that also has excellent operability.

(Means for Solving the Problems) For this purpose, the present invention provides a paper guide that is provided in a paper cassette and whose position can be changed according to the paper width;
It has a potentiometer that detects the position of the paper guide and changes its resistance value, a circuit that converts the change in resistance value into the number of dots corresponding to the printing density, and a circuit that shifts the printing start position by the number of dots. As described above, printing is started when the printing start value l is shifted.

(Function) According to the present invention, the paper cassette is provided with a paper guide whose position can be changed according to the paper width,
A potentiometer detects the position of the paper guide.

That is, when the paper guide moves, the resistance value of the potentiometer changes.

Then, the change in the resistance value is converted into the number of dots corresponding to the printing density, and the printing start position is shifted by the number of dots.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram of a page printer showing an embodiment of the present invention, and FIG. 2 is a perspective view of a manually inserted paper guide of the page printer of the present invention.

In the figure, 14 is a host computer connected above the page printer 10, which outputs print data and sends it to the controller 13. The controller 13, as a video I/F, edits and converts the print data and outputs it to the engine control circuit 11 as image data.

The VRI is a linear potentiometer, and its resistance value is changed by moving the paper guide 21 (FIG. 2) for manual insertion. In addition, IC+ is an operational amplifier, IC2 is an 8-bit AD converter, ICi is an l-chip microcomputer with an I10 port for mechanical control, and IC4 is a binary counter with a maximum count length n that can preset the count number and generates a pulse when counting ends. It is.

Further, 12 is an LED head equipped with n-dot LEDs.

Next, the operation of the page printer of the present invention will be explained.

First, when using non-standard paper by hand, position the paper by sliding the paper guide 21 shown in FIG. 2. Since the paper guide 21 moves symmetrically with respect to the center of the paper cassette 22, The paper width can be detected only by the position of one paper guide 21.

The paper guide 21 is connected to a potentiometer VR on the engine control board 23 via a position detection bar 24, and when its position changes, the potentiometer VR
, is detected by changing its resistance value.

The resistance value of potentiometer VR is converted into inheatance by IC, and converted into a digital signal by Icm converter. When the resistance value of the potentiometer VR is set to change from O to the maximum value with respect to the movement range of the paper guide 21, the I of the 8-bit AD converter
When using C, there are 20 pieces and 256 pieces, so 256 types of digital outputs are obtained.

That is, the position of the paper guide 21 can be detected at a pitch obtained by dividing its maximum moving distance into 256 equal parts.

For example, when printing from B4 size paper to envelopes, the maximum movement distance of the paper guide 21 is approximately 10
0 tm, and the positioning accuracy is approximately 0.4 m.
The printing start position can be calculated with this accuracy.

The digital output of the above-mentioned ICI is read by the IC, and the number of dots converted into printing density corresponding to the actual printing position 1 is set in the binary counter IC4.

For example, when using small paper in which the printing start position calculated by tCt is shifted by 30 mm relative to B4 size 1, and the print density is 240 dots/inch, the print density is 0.106 mm/inch. It becomes a dot.

Therefore, 30 (m+a) 10.1106 (/dot) −
Since the number of dots is 283 (dots), it is only necessary to shift the print start position inward by 283 dots.

Furthermore, the LED head 12 transfers print data to a shift register within the LED head 12 using n sample clocks. When the LATCH signal is input to the n-th pulse, n-dot data is printed.

Therefore, when the sample clock input to the LED head I2 is m pulses less than n pulses, LA
When the TCH signal is input, the print start position is shifted to the right by m pulses, that is, m dots.

For example, as mentioned above, set the print start position to standard size (
In order to shift to the right side of 3011IIl from B4),
When the sample clock is input to LED head 12 by n-mwn -283 pulses,
Just input the signal.

Therefore, a binary counter IC with a count length of n,
n-238 is preset, and after counting the n-238 pulses, the ICa count end signal, that is, the LATCII signal, is output to the LED head 12. Counter IC4 is reset by the LINE 5YNC signal, which is a horizontal one-dot line start signal.

By the above-described operation, it is possible to set the print start position of the print head of the page printer IO in correspondence with the position of the paper guide 21 in the case of manual insertion.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Function) As described above in detail, according to the present invention, a paper guide whose position can be changed according to the width of the paper is provided in the paper cassette, and the position of the paper guide is set to a resistance value using a potentiometer. The change in resistance value is converted to the number of dots corresponding to the printing density, and the printing start position is shifted by the number of dots.
The printing start position can be determined on the printer side.

Therefore, there is no need for the operator to input the print start position into the host computer in advance according to the paper size.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a page printer showing an embodiment of the present invention, Fig. 2 is a perspective view of the manual paper guide of the page printer of the present invention, and Fig. 3 is a paper feed state diagram when paper travel is based on one side. , FIG. 4 is a diagram showing a paper feeding state when paper travel is based on the center, FIG. 5 is a perspective view of a paper cassette in a conventional page printer, and FIG. 6 is a diagram showing a conventional printing start position determination method. IO... Page printer, 11... Engine control circuit, 12... LED head, 13... Controller, 14... Host computer, 21... Paper guide, 22... Paper cassette, 24 ...Position detection bar, lIR+...Potentiometer. Patent Applicant Oki Electric Industry Co., Ltd. Agent Patent Attorney Makoto Kawai (1 other person) August Page Printer Manual Insertion Paper Guide #8 Perspective View Figure 2 Wl'lJ! 211MdSMIL&! ! 1m Figure 3 Center base 11 Rei M! Fig. 4

Claims (1)

[Claims] (a) A paper guide provided in a paper cassette and whose position can be changed according to the paper width; (b) A potentiometer whose resistance value changes by detecting the position of the paper guide. (c) a circuit for converting the change in resistance value into a number of dots corresponding to printing density; and (d) a circuit for shifting a print start position by the number of dots.