JPS60151079A - Printer - Google Patents

Abstract

PURPOSE:To prevent useless printing with the printing position staggered from being generated, by a method wherein a sensor is provided for detecting the leading end of a recording paper being fed, and a positioned printed matter is secured even when the operation of a printer is stopped and restarted. CONSTITUTION:A CPU31 controls a motor-driving circuit 37 and a feed-controlling circuit 38 to output a driving pulse 23 and a feed-controlling signal 39, respectively, thereby starting the supply of a recording paper 12. When the leading end of the paper 12 reaches the position C of the sensor 18, correction data NC read from an ROM32 are set on a counter 35, and a counted value is corrected. Thereafter, the counted value is added to the correction data NC simultaneously with driving a stepping motor 24. When the trailing end of the paper 12 is detected by the sensor 18, the counted value is re-corrected in correspondence with the length in the feeding direction of the paper 12. Also thereafter, the counted value is added simultaneously with driving of the motor 24. The adding operation of the counter 35 is repeated until printing on one page is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer that prints on recording paper (sheets or cut sheets) that have been cut into predetermined sizes.

[Prior art]

There are two types of printers: those that use pre-cut recording paper and those that use recording paper that is wound into a roll. In a printer that uses recording paper cut in advance to a size such as Δ4 size or 84 size (hereinafter simply referred to as recording paper), the color, paper quality, etc. of the paper can be freely selected depending on the content to be printed. Further, it is also possible to use paper on which ruled lines and the like have already been printed, that is, preprinted paper, and to additionally print character information and the like on this paper.

However, in this type of printer, since the recording paper is cut in advance, it is necessary to adjust its position when printing. Particularly in printers that use preprinted paper, accurate positioning of printing positions is required in relation to preprinted ruled lines and the like.

FIG. 1 shows the main parts of such a printer. A large number of recording sheets 12 are stacked on the paper tray 11, and a feed roller 13 is driven so that the recording sheets 12 are sent one by one onto a recording sheet conveying path 14, starting from the lowest layer. The recording paper 12 is conveyed by a conveyance roller 15 arranged on a recording paper conveyance path. The feed roller 13 and the conveyance roller 15 are driven by a pulse motor (not shown), and the amount of conveyance thereof is controlled. That is, the position of the recording paper 12 being conveyed can be determined from the number of steps of the pulse motor after the start of feeding.

Now, the position of the conveyance start point Δ located on the exit side of the paper tray 11 is set as a reference point, and this is set as zero. The recording density of this printer that performs rusk scanning is 8 rusks/mm, and the conveyance pitch P of the recording paper 12 is 1/8 mm. At this time, the position of the leading edge of the recording paper 12 on the recording paper transport path 14 can be expressed by the following equation using the number of steps N.

L - P X N ...... (1) Distance from the transport start point Δ. It is assumed that the printing position B of the printing unit 17 exists at the position. In this case, from equation (1), the number of steps NIl =
The L/P position becomes the printing position.

However, in reality, the sequential feeding of the recording paper 12 is not necessarily carried out accurately due to slippage of the feeding roller 13 and the like. Therefore, conventional measures have been taken to correct errors in conveyance of recording paper. In other words, the recording paper 12 being conveyed
A sensor 18 is provided to detect the position of the leading end of the shaft, and the +m feed timing is corrected using this sensor 18.

FIG. 2 is for explaining such a correction operation conventionally used. The conveyance control circuit 21 controls the motor drive circuit 22 and generates a drive pulse 23 from the time when conveyance is started. The drive pulse 23 is supplied to the step motor 24, and the recording paper is (generally fed).The counter 25 counts the number of drive pulses 23, and calculates the number of steps N described above.
. A print start signal 26 is output at the time when the print start signal 26 is reached. The printing unit 27 starts printing at the same time.

By the way, before printing starts, the leading edge of the recording paper 12 is detected by the sensor 18.

At this point, the data generation circuit 28 outputs the correction data Nc. Here, the correction data Nc refers to the ideal number of steps corresponding to the position C of the sensor 18.

The counter 25 receives this correction data N. The count value is corrected to the contents of and the drive pulse 23 is added. Under normal conditions, there is almost no conveyance error caused by the conveyance roller 15, so
This allows the printing start position to be set almost accurately.

Now, printers are often provided with a pause switch for temporarily stopping a series of printing operations. If the operator presses this pause switch for some reason, the printer will come to an emergency stop. Resumption of operation is performed by operating a resume switch. However, in conventional printers, if the Bose/Resume button is operated after the leading edge of the recording paper 12 passes position C, the print start position is often not set accurately. This is due to slippage occurring in the first general feed roller 15 when the conveyance of the recording paper 12 is resumed, and mechanical distortion occurring in the conveyance driving force transmission system such as the belt. If the printing start position was not set correctly, unnecessary printing could occur. Particularly in the case of special recording paper with a limited number of sheets, such as preprint paper, there is a risk of paper shortage due to such wasteful printing.

[Purpose of the invention]

In view of these circumstances, it is an object of the present invention to provide a printer that can prevent the occurrence of wasteful printing due to misaligned printing positions.

[Structure of the Invention] The present invention includes a paper tray that stores a plurality of recording sheets cut into predetermined sizes, a printing section that prints on the recording sheets that are sequentially fed out one by one from the paper tray, and A sensor exists in or near the recording paper conveyance path between the printing section and the paper tray, and detects the leading edge of the recording paper during general feeding. A printing start control means performs timing control until the printing operation is started, and a signal to stop printing is generated during a period of time from when the leading edge of the recording paper is detected by the sensor until it arrives at the printing section. The printer is equipped with a paper ejection control means for ejecting the recording paper without performing a printing operation when the printing operation occurs. This prevents a situation where the conveyance is restarted after the leading edge of the recording paper passes the sensor, and avoids a shift in the printing position due to an error in the conveyance amount.

〔Example〕

The present invention will be described in detail with reference to Examples below.

FIG. 3 shows the main parts of the printer of this embodiment. This printer has a cp for controlling printing operations.
u <central processing unit) 31 is mounted on the tower. ROM (
A read-only memory (read-only memory) 32 stores a program for controlling the printer. RAM (Random Access Memory) 33 is a working memory. The sensor 18 is a reflective optical sensor as shown in FIG. 1, and detects the leading edge of the recording paper 12 using reflected light.

The counter 35 displays the position of the leading edge of the recording paper 12 as an integrated value of the counting clock 36. This counting clock 36 is generated by the drive pulse 23 output from the motor drive circuit 37 and the I(
(high) level transport control signal 39 and the AND circuit 4.
It is created by performing a logical AND with 1.

The drive pulse 23 is also supplied to a step motor 24 to drive the feed roller 13 and conveyance roller 15 shown in FIG. The drive timings of these rollers 13, 15 are individually controlled using electromagnetic clutches (not shown). The printing section 17 displays the number of steps N indicated by the counter 35. The printing operation is started when the number is counted.

The pause switch 43 is a switch that stops a series of operations for printing, and the resume switch 44 is a switch that restarts operations. Both of these are arranged on an operation panel (not shown). Data bus 45 is connected to many of the components described above, either directly or through the I10 (human output) port, to provide the necessary data transfer.

First, the normal operation of this printer will be explained with reference to FIG. When print data is sent to this printer from a data supply source (not shown), the CPU 31 controls the motor drive circuit 37.
and controls the transport control circuit 38 to output the drive pulse 23 and transport control signal 39. As a result, feeding of the recording paper 12 is started (step 2). When the step motor 24 is driven one step by the drive pulse 23 (step ■; Y), the contents of the initialized counter 35 become "1".
" is added (step ■). Such addition operation is repeated until the leading edge of the recording paper 12 is detected by the sensor 18 (step ■; Y).

When the leading edge of the recording paper 12 reaches the position C of the sensor 8, the correction data Nc read out from the ROM 32 is set in the counter 35, and the counted value is corrected (step 2). After this, along with driving the step motor 24 (step ■; Y), the correction data N. The count value is added to (step ■).

The conveyance of the recording paper 12 further progresses, and the trailing edge reaches the sensor 1.
8, the count value is corrected again in association with the length of the recording sheet in the feeding direction (step ■; Y). After this, as well as the step motor 24 is driven (step ■; Y), the count value is added (step ■). This addition operation of the counter 35 is 1
This continues until printing for one page is completed (step 0; Y). Even after the printing of the first page is completed, if there are still pages to be printed (step 0; N), a new sheet is fed (step 2), and the above-described operation is repeated. When printing of all pages is completed (step @; Y), the printing operation ends.

Next, the operation when the pause switch 43 of this printer is pressed will be explained with reference to FIG. When an interrupt occurs,
The CPU 31 determines whether the pause switch 43 has been pressed (step ■). When the boss switch 43 is pressed (Y), a predetermined pause process is performed (step [phase]). That is, if printing is already in progress, the printer is brought to an emergency stop as soon as the printing of the received data is completed. If the printing operation is not yet started, the conveyance of the recording paper 12 is immediately stopped.

The CPtJ 31 waits in this state until the resume switch 44 is pressed (step [phase]; N).

When the resume switch 44 is pressed (Y), the CPU 3
1 reads the count value of the counter 35 and determines whether the leading edge of the recording paper 12 is between positions C and B (step 0). If it does not exist during this time (N), normal resume processing is performed (step O). That is, conveyance of the recording paper 12 is restarted. After the leading edge of the recording paper 12 reaches the printing section ]7, the printing operation and driving of the step motor 24 are restarted. If the leading edge of the recording paper 12 has not reached position C, conveyance of the recording paper is started, and the count value is corrected at this position C (step 2 in FIG. 4).

1 If the leading edge of the recording paper 12 exists between positions C and B when the resume switch 44 is pressed (step @; y>
, 1. With the general feed control signal 39 cut off, the motor drive circuit 37 drives the step motor 24 at high speed, and the recording paper is ejected (step (2)). At this time, no printing operation is performed.

The recording paper 12 is stored in a discharge tray 52 by a discharge roller 51 (FIG. 1).

When the ejection of the recording paper 12 is completed, the counter 35 is reset, and the next recording paper 12 is fed (step [phase]). At this point, the print data to be printed on the previous recording paper is printed on the recording paper 12 sent out from the feed roller 13. Note that the recording paper 12 that has been discharged as a blank paper can be reused by setting it in the paper tray 12.

In this embodiment, a monochrome printing printer has been described, but the present invention can also be applied to a two-color or multicolor printing printer. In this case, if the printer stops in a predetermined interval, the recording paper is ejected without waiting for printing in one of the other colors. This is because creating printed matter with color misregistration wastes time.

〔Effect of the invention〕

As described above, according to the present invention, even if the printer stops and restarts (pause/resume), it is possible to ensure correctly positioned printed matter, and there is no need for inspection work for this purpose. .

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a printer, FIG. 2 is a block diagram showing main parts of a circuit of a conventional printer, FIG. 3 is a block diagram showing main parts of a circuit of a printer according to an embodiment of the present invention, and FIG. 4 and 5 are flowcharts showing the operation of the printer of this embodiment. 11...Paper tray, 12...Recording paper, 14...Recording paper transport path, 17...Printing section, 18...Sensor , 31...CPU. 3 1 Otsu 35...Counter, 37...Motor drive circuit, 38...Transportation control circuit, 43...Pause switch. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Umeo Yamauchi 4

Claims (1)

[Claims] A paper tray that accommodates a plurality of recording sheets cut to a predetermined size, a printing section that prints on the recording sheets that are sent out one by one from this paper tray, and a recording section between this printing section and the paper tray. a sensor that is located in or near the paper conveyance path and detects the leading edge of the recording paper being conveyed;
a print start control means for controlling the timing from when the sensor detects the leading edge of the recording paper until the printing section starts printing; and from when the leading edge of the recording paper is detected by the sensor to the printing section; 1. A printer comprising: a paper ejection control means for ejecting the recording paper without performing a printing operation when a signal to stop printing is generated during a time period until the arrival of the printer.