JPS6377769A - Sheet conveyor for recorder - Google Patents

Abstract

PURPOSE:To alleviate a load at the time of feeding a sheet by providing a guide roller separated at the time of recording and subjected to pressure contact at the time of feeding the sheet at the upstream side of a feed roller for applying a feeding force of the peripheral surface of a sheet feed roller. CONSTITUTION:When a feed roller 13 and a guide roller 12 at the upstream side of the roller 13 are contacted under pressure with the peripheral surface of a sheet feed roller 2 at the time of starting. When a sheet sensor 14A detects the fact that the sheet 1 arrives at the guide roller, it rotates the roller 2 to feed the sheet. When a sheet sensor 14B detects the fact that the sheet 1 arrives at the header, it rotates a release shaft 23 at a predetermined angle to drive a rockable arm 20 to a separating position against a spring 22 to release the pressure contact of the roller 12, and then records in a recording head 5 while pitch-feeding it. Thus, the load of sheet feeding can be alleviated, and the sheet feeding accuracy can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a sheet conveying device for a recording device such as a printer or a facsimile.

[Prior art]

A recording device such as a printer or facsimile feeds a sheet (recording medium such as paper or a thin plastic plate) from a sheet supply port, and a sheet feed roller driven by a sheet feed motor drives the sheet to a cue position where it faces the recording head. The sheet is fed 7M to the sheet, the line is fed while recording on the sheet based on the recording information, and after recording, the sheet is discharged to the outside from the sheet discharge port.

In the sheet conveyance device of such a recording device, a driven roller-type feed roller or pinch roller is installed on the circumference of the sheet feed roller, and the sheet is pressed against the sheet by this feed roller, and the resulting frictional force is used to increase the sheet conveyance force. It is configured to grant.

Incidentally, a conventional sheet conveying device of this kind has a configuration in which one or two feed rollers are provided that press against each other and move away from each other at the same time, and during recording, the sheet is conveyed by pressing the feed rollers.

However, in such conventional sheet conveying devices,
When the number of feed rollers is 1 (IM), there is a problem in that the guide function is insufficient during sheet feeding, and the sheet has a gap, resulting in poor cueing accuracy to the recording start position.

In addition, when two feed rollers are used, there is a problem that the sheet feeding load increases during recording, and the difference in tangential speed of the two feed rollers causes sheet waving and sheet feeding unevenness due to this. There was a problem.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet 1 [feeding device] of a recording apparatus that can solve the problems of the prior art, reduce the load during sheet feeding, and improve sheet feeding accuracy. .

[Means to achieve the purpose]

The present invention provides a sheet conveyance device for a recording apparatus that includes a sheet feed roller driven by a sheet feed motor, and a feed roller that is in pressure contact with the sheet feed roller and applies a feeding force to the sheet. The above object is achieved by providing a guide roller upstream from the feed roller during recording and pressed against during sheet feeding.

〔Example〕

The present invention will be specifically described below with reference to the drawings.

FIG. 4 shows a schematic configuration of a recording apparatus suitable for applying the present invention.

In Fig. 4, a guide rail 3 is installed parallel to the platen 2 in front of the platen 2 for bank-amplifying sheets (recording media such as paper or thin plastic plates), and the platen 2 moves (mainly runs) along this guide rail. A recording head 5 is mounted on a carriage 4.

The platen 2 also serves as a sheet feed roller, and is rotationally driven by a sheet feed motor (not shown).

In the illustrated example, the carriage 4 is controlled by a drive system composed of a drive pulley 7, a driven pulley 8, and a timing heald 9 stretched around these pulleys by a carriage motor.

On the front surface of the recording head 5, a dot forming means is provided in which a plurality (for example, 32) of heating elements, wires, or ink ejection ports are arranged in one or two vertical rows.

The illustrated example is a thermal transfer rewriting fl:1 device, in which a ribbon cassette 11 for feeding an ink ribbon 10 between a recording head (thermal head) 5 and a sheet 1 on a carriage 4 is replaced. Possibly installed.

During recording, the recording head 5 is pressed against the sheet 1 via the ink ribbon 10, and the carriage 4 scans the main in the direction of arrow P, and while feeding the ink ribbon 10 at the same speed, the dot forming means is controlled based on the recording information. Recording of a predetermined background is performed by driving the recording medium with the same speed.

Each time one line is recorded, the sheet feed roller 2 is rotated by a certain pinch angle to feed the sheet 1 in the direction of arrow S. When recording for one page is completed, the sheet feed roller 2 is rotated by a predetermined amount to discharge the sheet 1.

FIG. 1 shows a longitudinal section of a sheet conveying device according to the present invention,
Portions that are the same as or correspond to those in FIG. 4 are designated by the same numbers.

In FIG. 1, on the upstream side of the recording section of the sheet feeding roller 2, that is, in the illustrated example, two driven rollers 12 and 13 are provided at a predetermined interval in the feeding direction on the lower peripheral surface of the sheet feeding roller. are arranged so that they can be pressed and separated.

The roller 12 on the upstream side is a guide roller, and the roller 13 on the downstream side is a feed roller, and as will be described later, their functions are different.

A sheet sensor 14 is disposed between the feed roller 13 and the recording head 5 (immediately downstream of the feed roller 13 in the illustrated example) to detect whether or not the sheet 1 is present on the circumferential surface of the sheet feed roller 2. ing.

A pair of discharge rollers 15 and 16 are arranged downstream of the sheet feed roller 2 to discharge the sheet 1 that has passed through the recording section to the outside (upper part) of the recording apparatus.

In this way, the sheet inserted (fed) from the sheet supply port 17 is perforated in the circumferential surface of the sheet feed roller 2, is fed, and is ejected from the sheet ejection port 18 through the recording section and the ejection rollers 15 and 16. .

A sheet sensor 14A is provided near the guide roller 12 and near the downstream side of the foot roller 13 for detecting whether the sheet l has been fed to each position.
,1,1. B is placed.

However, the feed roller 3 applies a frictional force to the sheet by pressing against the sheet feed roller 2 through the sheet 1, and rotates the sheet feed roller 1 during recording etc. to pitch or convey the sheet. It has the function of ensuring and stabilizing the operation when performing it.

On the other hand, the guide roller 12 is separated from the sheet feed roller 2 during recording, but is pressed against the sheet feed roller 2 during sheet 1 feeding, and together with the feed roller 13 accurately and smoothly locates the beginning of the sheet before recording. It has the function to do.

In the actual design, the feed roller 13 is always in pressure contact regardless of the presence or absence of the sheet 1, and is configured to be released (separated) by a switch or manual operation when a sheet is manually inserted or taken out. There is.

On the other hand, the guide roller 12 is normally in pressure contact with the sheet feed roller 2, but at the time of writing, the sheet sensor 1
When 4B detects the presence of a sheet, it is configured to be automatically released (separated) by a motor (drive source) not shown.

Note that the sheet sensor 14A detects that the sheet 1 has reached the guide roller 12, and the other sheet sensor 14A detects that the sheet 1 has reached the guide roller 12.
This is to drive the sheet feed roller 2 until the beginning is detected at 4B to perform the beginning.

In this way, the guide roller 12 and the feed roller 13
Since the two have different operations, they each have separate support and drive mechanisms.

That is, the guide roller 12 and feed roller 13 are supported by separate swing arms 20 and 21, respectively, which are swingable about a fulcrum 9 provided on the chassis. The rotational supports of the swing arms 20 and 21 may be provided separately.

The swinging arm 20 that supports the guide roller 12 is biased by a spring 22 in the roller pressing direction (counterclockwise) and resists the spring 22 by rotating a release shaft 23, which is a camshaft, by a predetermined angle using a motor. and is driven to the separation (release) position.

On the other hand, the swinging arm 21 supporting the feed roller 13 is biased in the pressing direction (clockwise) by the spring 24, and the release shaft 25 consisting of a camshaft is rotated by a predetermined angle manually or automatically. is driven to the separation (release) position.

FIG. 2 is a block diagram of a control system of the sheet conveying device shown in FIG. 1.

In Figure 2, the CPU (control circuit) 30 of the recording device
receives various command signals and data signals from a host [31 such as a computer, and based on these signals, the driver 32 controls the sheet feed motor 33, the guide roller 12 release motor 34, the carriage motor 6, and the head down motor. It controls the motor 35, the discharge roller drive motor 36, etc., and also controls the dot forming means of the recording head 5 via the driver 37.

In addition, detection signals of sheet presence/absence from sheet sensors 14A and 1/IB installed at predetermined positions along the broadcast path (of sheet 1) are input to the CPtJ 30, and sheet conveyance operations and recording operations are controlled based on these signals.

FIG. 3 is a flowchart showing the operating procedure of the sheet feeding device according to the present invention described in FIGS. 1 and 2.

In FIG. 3, at the time of starting in step 100, both the guide roller 12 and the feed roller 13 are in pressure contact (step 1o1), and the sheet 1 is first fed in step 102.

In step 103, the sheet sensor 14A detects the
-1 has reached the guide roller 12 or not. If it has reached the guide roller 12, the sheet feed roller 104 is rotated in step 104 to feed the sheet.

In step 105, the sheet sensor 14B determines whether the sheet 1 has reached the cue position, and if it has reached the cue position, the process proceeds to step 10G and the guide roller 12 is released (separated).

Next, recording is started in step 107, and thereafter recording is performed while pitch-feeding the sheet with the sheet feeding roller 2.

When recording is completed in step 108, the sheet feed roller 2 and discharge rollers 15, 16 are driven to discharge the sheet 1 in step 109, and the operation is completed.

According to the embodiment described above, in addition to the feed roller 13 that feeds the sheet during recording, the guide roller 12 is provided on the upstream side of the sheet feed roller 2, and when feeding a sheet 1, both rollers are brought into pressure contact with each other so that the sheet is 1 general feed is performed, and the guide roller is released at the time of recording.
It was possible to accurately and stably guide the sheet during sheet feeding, and improve the cueing accuracy.

Also, since the guide roller 12 is released during recording,
It was possible to reduce the sheet feeding load, and also eliminate the waving and uneven feeding of the sheet 1 due to the speed difference between the two rollers 12 and 13, thereby achieving stable and accurate sheet feeding.

〔effect〕

As is clear from the above description, according to the present invention, there is provided a sheet conveyance device for a recording apparatus that can reduce the load of sheet conveyance and improve the precision of sheet conveyance.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a longitudinal sectional view of a sheet conveying device of a recording apparatus according to embodiments of the present invention, FIG. 2 is a block diagram of a control system of the sheet conveying device of FIG. 1, and FIG. This figure is a flowchart showing the operating procedure of the control system shown in FIG. 2, and FIG. 4 is a schematic perspective view of a recording apparatus suitable for carrying out the present invention. 1------1・--sheet, 2-・・-1111-
Sheet feed morph, 5-----1 recording head, 12-
·····Guide roller, 13·······Feed roller, 14 A, 14. B----- Sea I sensor, 23----- Camshaft for guide roller release. Agent Patent Attorney Yasushi Oto Takashi @7゛Ide Kano? Wan-wi feed゛o-7 Sheet 8, 02 Jitka Oido゛N Roller 1; K1 right or sheet 9 104 Corner party ``7J? Y 109 r ray F-, is book r

Claims (1)

[Claims] (1) In a sheet conveyance device of a recording apparatus having a sheet feed roller driven by a sheet feed motor and a feed roller that is in pressure contact with the sheet feed roller and applies a feeding force to the sheet, the peripheral surface of the sheet feed roller is A sheet conveyance device comprising a guide roller provided upstream of the feed roller and separated during recording and pressed against the sheet during sheet feeding.