JPS59104981A - Ink jet printer - Google Patents

Abstract

PURPOSE:To provide the titled printer not performing a printing action when a printing paper is not present at a printing position, wherein the printing action is performed only in a region detected by a sensor for detecting longitudinal and lateral end parts of the printing paper. CONSTITUTION:When the sensor S3 detects the leading end of the printing paper P and feeds a detection signal to a controlling part 2, an electric current according to the density of an image is supplied from the controlling part 2 to a heating element for a printing means 11. When the sensor S3 detects the trailing end of the paper P, the controlling part 2 controls the printing means 11 so that a printing region is terminated at a position inwardly spaced from the trailing end of the paper P by a predetermined distance.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an inkjet printer (two types, more specifically, an inkjet printer with an improved control system for the printing operation area and printing operation timing).

Prior Art Various types of inkjet printers have been known from the past, but the biggest advantage of inkjet printers is that the material for the printing material (hereinafter referred to as printing paper) can be selected arbitrarily, and conventional printing methods such as electrostatic printing This method does not require any specific paper, and also has advantages such as clear image quality and excellent printing speed.

In addition, unlike electronic copying machines, it does not use an indirect printing method in which the image on the photoreceptor is transferred to paper through a transfer process, and direct printing is possible, eliminating the need for a photoreceptor and reducing the cost. There are also advantages to the device.

However, these advantages can sometimes lead to disadvantageous problems.

For example, if you use the inkjet method, you can print anywhere, so if you perform a printing operation when there is no printing paper, the printing will be done on the guide member of the printing paper, and the printing paper will be fed. This results in the back side becoming dirty.

Purpose The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and provides an inkjet printer configured so that no printing operation is performed when no printing paper is present at the printing position. The purpose is to

In order to achieve the above object, the present invention provides a structure in which sensors are provided to detect the front, rear, left and right edges of printing paper, and printing operations can be performed only within the areas detected by these sensors. It was adopted.

Embodiments First Embodiment The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 illustrates a schematic structure of an inkjet printer according to the present invention. The inkjet printer according to the present invention is roughly divided into an original reading section 1, a control section 2, and a printer section 3.

In this embodiment, a document table 4 that moves toward the reading section 1 is provided, and a document 5 is placed on this document table 4. As the document table 4 moves, the document 5 is imaged on an image forming member, for example, a CCD 7, via a lens 6.

The image formed on the image forming member 7 becomes an electrical signal and is sent to the control section 2.

The control unit 2 changes the received signal as appropriate and supplies a signal for controlling, for example, the printing start timing or the conveyance speed of the printing paper.

That is, for example, when a reduced image is required, control is performed such as reducing the printing width and slowing down the conveyance speed of the printing paper.

On the other hand, the printer section 3 has a feeding roller 8 rotated by a motor M1 controlled by the control section 2, and the printing paper P is fed between these feeding rollers.

The printing paper P sent by the feeding roller 8 reaches the feeding roller 9 which is also rotated by the motor M1, and
Expelled from the device.

An etching wheel 1° is positioned above the conveying roller 9, and makes point contact with the printing paper P guided between the conveying roller 9 and the conveying roller 9 to prevent the image from being smeared by rubbing ink. and send it out.

During printing, the printing means 11 is guided to the printing section between the feeding roller 8 and the conveying roller 9. This printing means 11 is composed of, for example, a bubble jet printing means disclosed by the present applicant, and has a nozzle lla at its lower end.

This printing means 11 is also controlled by the control section 2.

Reference numeral 12 is a displacement mechanism for the printing means 11, which displaces the printing means 11 between a printing position and a non-printing position.

That is, the displacement mechanism has two 9-links 13 and 14 that are rotatably supported, and a link arm 15 is rotatably supported at the tip of each link. The printing means 11 is fixed to the tip.

Further, the displacement mechanism 12 has a gear 16 rotated by a motor M2, and this gear 16 meshes with a toothed portion 14a formed at the lower end of one link 14. 'Motor M2
The rotation of is controlled by the control section 2.

In FIG. 1, the symbol Sl indicates a sensor that detects when the displacement mechanism 12 is activated and the printing means 11 is in the raised position, and S2 is a sensor that detects that the printing means 11 is in the lowered position. . Further, a stopper 17 is provided near the sensor S2 to control the lowering limit of the link arm 15, that is, the lowering limit of the printing means 11. The detection signals of these sensors +S, , S2 are sent to the control section 2.

18 is an ink volatilization prevention means at the tip of the nozzle 11a, and has a container 19.
9 is filled with a solvent 2G of the same quality as the ink, and an ink-impregnated member 21 made of urethane foam or the like is impregnated with this solvent 2o. Therefore, the impregnated member 2
1 is always in a closed state.

Next, the operation of this embodiment configured as above will be explained.

When a print button (not shown) is pressed, the document table 4 on which the document 5 is placed starts to move, and a scanned image of the document is projected onto the image forming member 7 via the lens 6. This image forming member 7 is arranged in a direction perpendicular to the scanning direction of the original 5.

The image detected by the reading means is converted into a digital signal according to the density and sent to the control section 2.

Since the control unit 2 controls the motor M so that the number of rotations of the feeding roller 8 is obtained according to a predetermined magnification, the paper is fed at a predetermined speed.

The leading edge of this printing paper P is detected by sensor S3,
When this detection signal is sent to the control section 2, the control section 2 supplies a current corresponding to the density of the image to a heating element (not shown) of the printing means 11.

In addition, to change the image position before and after the conveyance direction of the printing paper P,
This is performed by changing the printing timing by being instructed by an operation button on an operation panel (not shown) and edited by the control unit 2. Also, if there is an instruction to change the magnification of the image,
The feeding speed or printing pitch is changed.

By the way, since the arrangement of the nozzles lla is perpendicular to the conveyance direction of the printing paper P, the change in the printing position in the width direction of the printing paper P is also edited by the control unit 2, and the printing in the width direction of the printing paper P is changed. This is done by changing the start time.

Further, if there is an instruction for a variable magnification image, the ink ejection width is changed.

As the printing operation progresses, the trailing edge of the printing paper P reaches the sensor S.
3, the control section 2 controls the printing means 11 so that the printing area ends within a predetermined distance from the trailing edge of the printing paper P, and printing ends.

If the printing area is controlled in this manner, ink is not ejected to areas where there is no printing paper, and it is possible to prevent the device and the paper from becoming dirty.

Note that the width of the printing paper can be easily detected by detecting a signal for detecting a cassette containing paper (not shown), or by arranging a sensor in the width direction of the printing paper P.

'' When the two consecutive printing operations are completed, the motor M2 is rotated by the control section 2, and the gear 16 is rotated in the clockwise direction in FIG.

As a result, the tooth portion 14a of the link 14 that meshes with the gear 16
is rotated, the links 13 and 14 are rotated counterclockwise in FIG. 1, and the link arm 15 accordingly moves to the left in FIG. The nozzle lla rises while drawing a predetermined trajectory, and when it reaches above the volatilization prevention means 18 begins to descend, and the tip of the nozzle lla fits into the impregnated member 21 inside the volatilization prevention means 18.

The upward movement of the printing means 11 is regulated by stopping the rotation of the remote motor M2 in the control device 2 when the link 13 is detected by the sensor s1.

The tip of the nozzle lla is an impregnated member 2 impregnated with a solvent 2o.
1, the ink inside the nozzle lla will not volatilize or solidify. This is to prevent ink from being ejected when printing is started again.

On the other hand, when a second printing command is sent from the control device 2 to the printing means 11, an ink ejection command is sent to the printing means 11 immediately before the printing means 11 starts transferring. This ejection command is extremely short-term, and is used to remove impurities attached to the nozzle lla before printing.

The motor M2 is rotated by a signal from the control device 2, and the displacement mechanism 12 starts moving from the position shown by the chain line in FIG. 1 to the position shown by the solid line. When the link 7-415 reaches its lower limit, its position is detected by the sensor s2, the rotation of the motor M2 is stopped, and the displacement mechanism 12 stops operating.

Mechanical position control of the link arm 15 is performed using a stopper 17.
The link arm 15 is moved by the stopper 17.
The position where the nozzle lla of the printing means 11 contacts becomes the proper printing position.

Note that the amount of ink ejected from the nozzle lla of the printing means 11 is not changed during continuous printing. This is because during continuous printing, the ink is close to a continuous discharge state,
This is because ink volatilization hardly occurs. However, during individual printing, which is not continuous printing, control is performed by the control section 2 based on an instruction for the number of print sheets on an operation panel (not shown).

Since this embodiment is configured as described above, printing is always performed only in the designated printing area, and ink may be ejected outside the printing area and stain the printing paper, or if there is no printing paper, the ink may be There will be no inconveniences such as contamination of the device due to discharge.

- The printing paper is detected and the printing area is specified as described in 3. However, if there is no printing paper, all the printing paper detection sensors do not generate a detection signal, and the control unit detects that the printing area is It is determined that the person is absent.

Therefore, if there is no printing paper, there is no area to print, the printing means 11 does not operate, and no ink is ejected. Therefore, inconveniences such as the koji making and the back side of the printing paper will not occur.

Second Embodiment FIGS. 2 and 3 explain another embodiment of the present invention. In this embodiment, the nozzles are arranged in the same direction as the conveyance direction of the printing paper P. An example is shown below.

In FIGS. 2 and 3, the reference numeral 22 is a printing means, which has nozzles 22a arranged on its lower surface in parallel to the conveyance direction of the printing paper P, and is slidably attached to the guide rod 23. There is. One end of the printing means 22 is fixed in the middle of a wire 24 arranged parallel to the guide rod 23. The wire 24 connects the drive pulley 25 and the driven pulley 2
The drive pulley 25 is driven by a motor M3 controlled by the control section 2.

The movement range of the printing means 22 is larger than the printing width 4, and the movement limit of the printing means 22 is detected by sensors S6 and S7. A volatilization prevention means 27 is arranged at one end of the movement of the printing means 22 in the T direction.

The volatilization prevention means 27 has a container 30 at the tip of an arm 29 rotatably supported by a shaft 28, and an impregnated member 31 impregnated with a solvent is housed in the container 30.

A spring 32 is stretched between the arm 29 and the fixed part of the device, giving it the ability to rotate clockwise in FIG.

A solenoid 3 is connected between the shaft 28 of the arm 29 and the container 30.
3 is arranged, and the tip of the rod 7 is rotatably connected to the arm 29.

In addition, in FIG. 3, the symbol 34 is the arm 29.
This is a stopper that limits the clockwise rotation.

In a printing device having such a structure, the array width of the nozzles 22a, that is, the printing width 12 is the feed amount of the printing paper P, and when the printing cycle on the printing paper P in the width direction is completed, the printing paper P will be fed for 12 minutes. only.

In addition, the width of the printing paper, for example, the size of M or S4, etc., can be detected by --- Ima→Sensor S4. This is done by S. The size of the printing paper is detected by these sensors fS+ and Ss,
The scanning length of the printing means 22 in the width direction of the printing paper is determined.

Note that the sensor S3 shown in FIG. 1 is used to detect the leading and trailing edges of the printing paper.

and S4. The print area is determined by S.

Based on the structure described above, when a printing command is sent from the control section, the motor M3 starts rotating, and the printing means 22 starts moving via the wire 24, and in response to the printing command from the control section, the motor M3 starts rotating. In response, ink is ejected from the nozzle 22a and printing is started.

When all the printing is completed, the printing means 22 is sent out of the printing scanning area shown by the chain line in FIG. 2, is detected by the sensor S7, and stops.

Until the printing end signal is sent, the volatilization prevention means 27 is maintained in a horizontal state by the tensile force of the spring 32, as shown in FIG. In this case, the solenoid 33 is energized just before or during the movement to the position shown by the chain line, and the arm 29 resists the tensile force of the spring 32 and moves in the counterclockwise direction as shown by the solid line. It is rotated and becomes ready to receive the nozzle 22a. When the position of the printing means 22 is detected by the sensor S7 and stopped, the energization to the solenoid 33 is also cut off, and the tensile force of the spring 32 causes the arm 29 to return to the horizontal state as shown by the chain line in FIG. This position is regulated by a stopper 34, but when the nozzle 22a is in a horizontal position, the tip of the nozzle 22a is inserted into the solvent-impregnated member 31. In this way, volatilization is prevented.

When printing starts again, the solenoid 33 is energized, the arm 29 moves away from the nozzle 22a as shown by the solid line in FIG. 3, the printing means 22 returns to the home position, and the next printing starts.

Immediately before the start of printing, when the nozzle 22a is in the impregnation member 31, instantaneous ink is ejected to remove impurities.

Since this embodiment is configured as described above, similar to the first embodiment described above, printing is not performed outside the printing area, and the printing paper is not smeared (and when there is no printing paper, ink is not printed). is discharged without contaminating the equipment or other parts.

Effects As is clear from the above explanation, according to the present invention, sensors are provided to detect the leading edge in the conveyance direction, the trailing edge, and both ends in the width direction of the printing paper, and in the printing area detected by these sensors, Since the structure is configured so that printing can be performed only in the specified printing area on the printing paper, ink is not ejected to other areas (,.

There is no risk of staining the printing paper (also, since no ink is ejected even when there is no printing paper, the device will not be soiled, and there is no risk of staining the back side of the printing paper, etc.).

[Brief explanation of the drawing]

FIG. 1 shows a schematic configuration of an embodiment of the present invention, and FIG.
Figures 3 and 3 illustrate other embodiments of the present invention.
The second factor is a perspective view illustrating the schematic structure, and Figure 'fJ3 is an explanatory ratio showing the structure of the volatilization prevention means. DESCRIPTION OF SYMBOLS 1... Reading part 2... Control part 3... Printer part 8... Feeding roller 9... Conveyance roller 11... Printing means 12... Displacement mechanism
15...9 units M, ~MB...motor P...printing paper S, ~S7...sensor

Claims (2)

[Claims] (1) In an inkjet printer that prints by ejecting ink from an inkjet nozzle, sensors are installed to detect the leading edge, trailing edge, and both widthwise edges of printing paper in the conveyance direction, and the control device uses detection signals from these sensors to An inkjet printer characterized in that it is configured to be able to print only within a determined printing area. (2) The inkjet printer according to claim 1, wherein if there is no printing paper, it can be determined that there is no printing paper.