JPS606535A - Recording paper conveyance controller - Google Patents

Abstract

PURPOSE:To exactly control the conveyance of recording paper at the time of resumption of the conveyance, by providing a sensor, a push detector and a recording paper size detector and applying the outputs of these detectors to a compensation coefficient calculator. CONSTITUTION:A sensor 16, a push detector 21 and a recording paper size detector 22 are provided. The outputs of these detectors are applied to a compensation coefficient calculator 33 so that compensation data for conveying recording paper 12 to a recording start position are calculated at the time of resumption of conveyance of the paper. The recording paper 12 is thus accurately set in the recording start position. According to this constitution, the conveyance of the recording paper 12 is exactly controlled after the conveyance stopped as the recording paper sent out of a paper feed tray 23 in a bottom feed method still has the rear edge in the tray before the beginning of recording is resumed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording paper conveyance control device used to convey recording paper cut into a predetermined size to a recording section.

[Prior art]

2. Description of the Related Art In image information processing apparatuses such as facsimile machines and copying machines, as the apparatuses become more compact, there is a tendency for the feeding path for conveying recording paper to a recording section to be shortened.

FIG. 1 shows the main parts of a thermal recording apparatus using cut paper as recording paper. A plurality of sheets of recording paper 12 cut to a predetermined size are stacked on the paper feed tray 11 . This paper feed tray 11 is configured to feed recording paper 12 using a bottom feed method. That is, the feed roller 13 is arranged at the bottom of the paper feed tray 11, and through an opening (not shown) at the bottom of the paper feed tray, it comes into contact with the recording paper 12L located at the lowest layer and feeds it out. ing. A paper pressing member 14 is arranged above the paper feed tray 12, and is adapted to press the recording paper 12L in the direction of the feed roller 13.

In this device, when a step motor (not shown) is driven and the feed roller 13 rotates in the direction of the arrow in the figure, the lowest layer of recording paper 12L is sent out and travels along a conveyance path 15 shown by a chain line. A sensor 16 is arranged in the middle of the conveyance path 15. When the sensor 16 detects the leading edge of the recording paper 12L, the conveyance amount of the recording paper 12L is controlled using this point as a reference. That is, a control circuit (not shown) counts the number of drive pulses applied to the step motor, and starts the recording operation when the number reaches a predetermined number of pulses. At this time, the leading edge of the recording paper 12L should be at a predetermined recording start position that has slightly passed between the thermal head 17 and the back roll 18.

Now, suppose that after the leading edge of the recording paper 12L passes the sensor 16, the operation of the apparatus stops for some reason. Such cases include when a user of the device presses a stop button (not shown) for safety reasons, or when a stop signal is supplied from a host computer as an external data generation source. Once the conveyance of the recording paper 12L is once stopped in this way, even if the remaining number of drive pulses are applied to the step motor thereafter, the recording paper 12L may not be able to reach the recording start position described above.

In other words, if recording is started when the remaining number of drive pulses have been applied, the recording start position will be shifted.
In extreme cases, image information may be missing. This is recording paper 1
When 2L resumes withdrawal, the rear end and other recording paper 12
This is because static friction acts between the two and hinders conveyance.

The degree of deviation of the recording start position varies depending on the stacking state of the recording paper 12 in the paper feed tray 11 and the stop position of the recording paper 12L. Conventionally, it has not been possible to control the conveyance of the recording paper 12L in response to such a shift. Therefore, if the apparatus stops after the leading edge of the recording paper 12L passes the sensor 16 and before recording starts,
A method has been adopted in which recording on the recording paper 12L is abandoned and the paper is ejected from the apparatus as a blank sheet.

However, this is not at all desirable for the user of the device.

[Purpose of the invention]

In view of these circumstances, the present invention has been developed in such a manner that the recording paper sent out from the paper feed tray using the bottom feed method leaves the trailing edge portion inside the paper feed tray, and the conveyance of the recording paper is stopped before recording starts. It is an object of the present invention to provide a recording paper conveyance control device that can accurately control the conveyance of recording paper when the conveyance of the recording paper is resumed.

[Structure of the invention]

The present invention includes a stop position data storage means for recording data regarding the stop position when one general feed is stopped before the leading edge of the recording paper reaches the recording start position, and a trailing edge of the recording paper stopped during conveyance. paper feed tray related data measuring means for measuring frictional force or data related to which part of the recording paper does not reach when the portion is present in the paper feed tray;
a correction data calculation means for calculating correction data for transporting the recording paper to a recording start position when transport of the recording paper is restarted based on at least two types of data, stop position data and paper feed tray related data; The recording paper conveyance control device is provided with a motor drive control means for resetting the number of drive pulses to be supplied to the pulse motor in order to cause one general feed to the starting position in accordance with the correction data. In addition to dynamic or static frictional force, the paper feed tray related data includes various data such as the amount of recording paper accumulated, weight, and size. As described above, the present invention achieves the above object by setting the drive pulses necessary to convey the recording paper to the recording position, taking into account the influence of the paper feed tray at the time of starting the retransmission of the recording paper.

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

FIG. 2 shows the recording paper conveyance control device of this embodiment used in a thermal recording apparatus. This device is equipped with two detectors: a suppression detector 21 and a recording paper size detector 22.

FIG. 3 shows the arrangement of these detectors in the paper feed section. The suppression detector 21 detects the pressure applied to the lowest layer of recording paper 12L from the relationship with the amount of recording paper 12 stacked in the paper feeder button 23.
A pressing roller 24 is provided which rolls into contact with the uppermost layer of No. 2 and presses it downward by its own weight. One end of an arm 25 is attached to the rotating shaft of the pressing roller 24. The other end of the arm 25 is attached to a rotating shaft of a potentiometer 26 fixedly mounted on a stationary member (not shown).

As the amount of accumulated recording paper 12 decreases, the arm 25 changes at a time δ in the figure.
It is designed to rotate in one direction, and the potentiometer 26 detects this as a change in resistance value. The detected resistance value is converted into a voltage and output as a suppression signal 27.

On the other hand, the paper feed cassette 23 contains the recording paper 12 stored therein.
Two magnets 28 with different arrangement patterns depending on the size of
．． 29 is attached. Recording paper strength detector 22
magnetically detects this arrangement pattern and detects the size of the recording paper 12. The detection result is output as a recording paper size signal 31.

The suppression signal 27 is an analog signal, and the A/D converter 3
2 is converted into a digital signal and input to the correction coefficient calculator 33. The recording paper size signal 31 is similarly input to the correction coefficient calculator 33.

Now, when a start button (not shown) of the thermal recording device is pressed, a conveyance start signal 34 is supplied to the motor drive circuit 35, and a drive pulse 37 for driving the step motor 36 is generated. As a result, the step motor 36 starts rotating, and the feed roller 13 shown in FIG. 3 rotates in the direction of the arrow. At the same time, feeding of the lowest layer of recording paper 12L is started.

When the leading edge of the recording paper 12L reaches the center point of the sensor 16, the leading edge is detected and a detection signal 39 is output. When the pulse number setting circuit 41 manually inputs this detection signal 39,
Bliss counter 43 with numerical value N as setting signal 42
and preset it. The number N is the fourth
As shown in the figure, this is a value expressed as the number of driving pulses of the step motor corresponding to the distance between the sensor 16 and the recording position of the thermal head 17.

The preset counter 43 receives the drive pulse 37, and subtracts the value N after it is set. □
If the recording paper 12L is conveyed without stopping midway, the recording start signal 45 is output at the time when the Nth drive pulse 37 is generated after the detection signal 39 is generated. The recording start signal 45 is supplied to a recording control circuit (not shown), and thermal recording by the thermal radar 17 is started.

On the other hand, assume that the recording paper 12L stops midway along the conveyance path 15 for some reason. Let S be the stopping position in this case. If n driving pulses 37 are generated from the sensor 16 to the stop position S, the preset counter 43 supplies the subtraction value (N - n) at this time to the correction coefficient calculator 33 as the remaining conveyance amount data 46.

As the above results, the correction coefficient calculator 33 contains (i) data regarding the pressing force applied to the recording paper 12L from other recording papers 12, and (ii) records stored in the paper feed cassette 23. Data regarding the size of the paper 12 and (iii) data regarding the remaining conveyance amount to the recording position required when resuming withdrawal of the recording paper 12L are input. The correction coefficient calculator 33 has a read memory area divided into a total of nine memory areas 49 as shown in FIG.
Only memory 48 is arranged. Suppression signal 27 (
(Fig. 2) as heavy (H), medium (M), and light (L).
In addition, there are three types of recording paper sizes (84 size, △
4 size, 85 size), each of these combinations corresponds to each memory area 49. A correction coefficient α is written in each memory area 49 in comparison with the remaining transport amount data. Zunawara correction coefficient calculator 33
The read/run 9/memory 48 address is specified in the form of a combination of three data input manually, and the read correction coefficient α is sent to the pulse number setting circuit 41 as correction data 51. It is now being supplied.

FIG. 6 shows an example of the contents of data written to a certain memory area in the read-only memory. The origin on the horizontal axis of this figure is the position of the sensor 16, and the point with the numerical value N is the recording position. Even if the stop position of the recording paper is directly above the sensor 16, the correction coefficient α, that is, the increase rate of the drive pulse is greater than 1. This takes into consideration the coefficient of static friction between the recording sheets at the time when re-feeding of the recording sheets is started. The correction coefficient α becomes larger as the stop position approaches the recording position. This is because the number of drive pulses to be corrected is relatively reduced. Furthermore, the 6th
The data shown in the figure was obtained experimentally by setting various conditions such as the size of recording paper.

The correction data 51 output from the correction coefficient calculator 33 in this manner is manually input to the pulse number setting circuit 41. The pulse number setting circuit 51 multiplies the remaining conveyance amount data 46 and the correction data 51.

That is, the calculation of (N-n)Xα is performed, and the setting signal 42
It is preset in the preset counter 43 as follows. Thereafter, when the conveyance of the stopped recording paper 12L is resumed, the preset counter 43 subtracts this new value using the drive pulse 37. When the content becomes zero, a recording start signal 45 is output. As a result, the recording start position is corrected.

Let us express an example of the above-mentioned recording paper conveyance control using specific numerical values.

Each time one pulse of the drive pulse 37 is applied to the pulse motor 36, the feed roller 13 moves the recording paper 12L to 1/b.The distance between the detection position of the sensor 16 and the recording position of the thermal head 17 is set to 20 mm. At this time, the numerical value N becomes the numerical value 16 ( ), which is the sum of both values. However, recording paper 1
There is some slip between 2L and the feed roller 13. Therefore, the numerical value N that is actually set is a value somewhat larger than this. For example, assume that the value is 180. If the recording paper 12F does not stop between the sensor 16 and the recording position, recording will start when 180 driving pulses 37 are generated.

The curve for the correction coefficient α shown in FIG. 6 is given as a digital quantity representing the stop position divided into eight sections. Assume that the recording paper 12L stops at the stop position S of the 50th pulse in the figure, and that the correction coefficient α at this time is 1.06. In this case, the pulses P applied until the start of recording when transport is resumed are as follows.

P = (N-n)

〔Effect of the invention〕

As described above, according to the present invention, the recording start position can be accurately guaranteed even in a recording apparatus using cut paper. Furthermore, even if the apparatus temporarily stops before starting recording, there is no need to eject blank paper, and no recording paper is wasted.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a thermal recording apparatus for explaining conventional recording conveyance control, and FIGS. 2 to 6 are for explaining an embodiment of the present invention. Of these, FIG. A block diagram showing the configuration of the recording paper conveyance control device, FIG. 3 is a schematic configuration diagram of the paper feeding section of the thermal recording device, FIG. 4 is a principle diagram showing the principle of 1st general feed control, and FIG. 5 is a correction diagram. FIG. 6 is an explanatory diagram of the memory area arrangement of the read-only memory in the coefficient calculator, and is an explanatory diagram showing the contents of data stored in one of the memory areas. 12... Recording paper, 16... Sensor, 17... Thermal head (recording position), 21...
... Pressure detector, 22 ... Recording paper size detector, 23 ...
・Paper feed cassette (paper feed tray), 33... Correction coefficient calculator, 35... Motor drive circuit, 36... Step motor, 37... - Drive pulse, 41...Pulse number setting circuit, 43...Preset counter. Applicant Fuji Xerox Co., Ltd. Attorney Umeo Yamauchi Figure 1 Figure 20 Figure 3 Figure 6 Figure 4 Figure 5 Open Figure 6

Claims (1)

[Claims] In a recording device that feeds recording paper cut to a predetermined size from a bottom-feed paper feed tray to record, the stop position is when the conveyance of the recording paper is stopped before the leading edge of the recording paper reaches the recording start position. and a stop position data storage means for storing data related to the frictional force or data related to this when the rear end portion of the recording paper that stopped during withdrawal is present in the paper feed tray and other recording paper does not reach it. Paper feed tray-related data to be measured Based on at least two types of data, ie, stop-normal position data and paper feed tray-related data, the paper feed tray-related data to be measured is generally measured when the paper conveyance mountain is opened to the recording start position. A correction data calculation means for calculating correction data to be sent, and a motor drive control means for resetting the number of drive pulses to be supplied to the pulse motor in order to transport the paper to the recording start position according to the correction data. A recording paper conveyance control device characterized by: