JPH0692179B2 - Image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image forming apparatus such as a printer, and more particularly to an image forming apparatus characterized by a paper feed control unit.

2. Description of the Related Art Generally, for example, in an ink jet serial printer, since it takes time for the ink adhering to the paper to dry, a line feed (paper feed) operation for printing the next line is started immediately after the line printing is completed. This may cause paper stains.

Therefore, in the conventional printer, a predetermined delay time (delay time) is provided every time line printing is completed, and the line feed operation is started after waiting for the delay time to elapse.

However, if the predetermined delay time elapses after each line printing is completed, there is a problem that the printing throughput is significantly reduced.

Aim The present invention has been made in view of the above points, and an object thereof is to improve printing throughput.

In order to achieve the above object, the present invention provides an image including image forming means for forming an image on a recording sheet, and sheet discharging means for discharging the recording sheet on which an image is formed by the image forming means. In the forming apparatus, the above-mentioned paper discharging means judges whether or not it is immediately after image formation, and when this judgment means judges that it is not immediately after image formation, the paper feeding operation is immediately performed to perform image formation. If it is determined to be immediately after that, the paper feed amount of the recording paper is compared with the distance from the print position to the member that comes into contact with the image on the recording paper first, and the paper feed amount must be the distance or more. For example, the paper feed control means performs a paper feed operation immediately and, if the paper feed amount is equal to or more than the distance, carries out the paper feed operation after a lapse of a predetermined waiting time.

The image forming apparatus includes an image forming unit that forms an image on a recording sheet and a sheet discharging unit that discharges the recording sheet on which an image is formed by the image forming unit. Then, the paper discharge means determines a first judgment means for judging whether or not the image has just been formed, a second judgment means for judging whether or not the automatic sheet feeding device is mounted, and a first judgment means. When it is determined by the determination means that the image has not been formed immediately, or the above second
If it is determined by the determining means of No. 1 that the automatic paper feeding device is not installed, the paper feeding operation is immediately performed, and the first determining means determines that the image formation has just been performed, and the second determination is made. When it is determined by the determining means that the automatic paper feeding device is installed, the paper feed amount of the recording paper is compared with the distance from the print position to the paper ejection roller of the automatic paper feeding device, And a paper feed control means for carrying out the paper feed operation immediately if the feed amount is not the distance or more and carrying out the paper feed operation after a predetermined waiting time has elapsed if the paper feed amount is the distance or more. Also provide.

Further, in these image forming apparatuses, the image forming means may be an ink jet recording means.

Hereinafter, a specific description will be given based on an embodiment of the present invention.

FIG. 1 is a block diagram showing the construction of the paper discharge means in the image forming apparatus according to the present invention.

This image forming apparatus is provided with an image forming unit that forms an image on a recording sheet (hereinafter simply referred to as “sheet”) and a sheet discharging unit that discharges a sheet on which an image is formed by the image forming unit. As shown in FIG. 1, the paper means comprises a discrimination means A, a paper feed control means B and a paper feed mechanism C.

The determination unit A is a unit that determines whether or not the image has just been formed.

The paper feed control unit B performs the paper feed operation immediately when it is determined by the discriminating unit A that the image has not been formed immediately after, and when it is determined that the image has just been formed, the paper feed amount and the print position of the paper are determined. Compare the distance to the member that comes into contact with the image on the paper first, and if the paper feed amount is not the above distance or more, the paper feed operation is performed immediately. The paper feed mechanism C is controlled so that the paper feed operation is performed after a lapse of time.

When this image forming apparatus can be equipped with an automatic sheet feeder (hereinafter abbreviated as "ASF") which is an automatic sheet feeding device, the first discriminating means for discriminating whether or not the image has just been formed as the discriminating means. And a second discriminating means for discriminating whether or not the ASF is installed.

Then, the paper feed control unit B determines that the first determination unit of the determination unit A determines that it is not immediately after image formation, or the second determination unit determines that the ASF is not mounted. When the paper feeding operation is performed immediately and it is determined by each of the determination means that the image has just been formed and the ASF is installed, the AS is determined from the paper feeding amount and the printing position of the paper.
Compare with the distance to the paper ejection roller of F, if the paper feed amount is not more than the above distance, the paper feeding operation is performed immediately.If the paper feed amount is more than the above distance, after a predetermined waiting time has elapsed The paper feeding mechanism is controlled to perform the paper feeding operation.

FIG. 2 is an external perspective view showing an example of a printer which is an image forming apparatus embodying the present invention.

The printer 1 has an ink jet recording means as an image forming means and can be equipped with an ASF capable of selectively and automatically feeding sheets of a plurality of sizes.

First, the printer 1 will be described. The outer casing of the printer 1 is composed of a lower case 3 and an upper case 4 accommodating a mechanical section and a control section, and a cover 5 is attached to the upper case 4 so as to be openable and closable.

An operation panel 6 is attached to the front of the printer 1.

As shown in FIG. 3, the operation panel 6 is provided with a pause switch 10 for instructing switching between pause / not pose (online / offline), a reset switch 11 for instructing reset, and a line feed (line feed). A line feed (LF) switch 12, a page break (FF) switch 13 for instructing a page break (form / feed), and an automatic insertion switch 14 for instructing automatic insertion of paper are provided.

As shown in the figure, the operation panel 6 also includes a pause lamp 15 for displaying a pause state, a paper-less lamp 16 for displaying a paper end, and an ink-free lamp 17 for indicating an ink shortage as shown in FIG. , Error lamp 18 that displays an error and cover open lamp that displays that the cover 5 is open
19, and a bail open lamp 20 that displays the paper bail open,
A standby lamp 21 that displays a standby state and a pause state,
A power lamp 22 for indicating power-on is attached.

Further, on the back surface of the printer 1, as shown in FIG. 4, on an interface board 54 of a control unit described later, eight DIP switches 25 and four DIP switches 26 for setting various modes are provided. Separately from when the power is turned on, a reset switch 27 for instructing an initial reset and a Centronics interface connector 28 for connecting to a host system are attached.

Table 1 shows the states and functions (modes) of the switches of the DIP switch 25, that is, switches Nos. 1 to 8.

Table 2 shows the states and functions (modes) of the switches No. 1 to No. 4 of the DIP switch 26.

The reset switch 27 will be described later in the description of the control unit.

Also, the interface with the host side is not limited to the Centronics interface.

FIG. 5A is a perspective view showing a mechanical portion of the printer 1.

In this mechanism section, a platen 31 for wrapping and feeding a sheet at a substantially center is rotatably supported.

The platen 31 includes a line feed (LF) motor 32, which is a stepping motor, and a timing pulley 33 and a timing belt 34 fixed to the rotary shaft of the LF motor 32 and a timing pulley (not shown) fixed to the shaft of the platen 31. It is driven to rotate through and automatically feeds the paper.

Further, knobs 35, 35 for manually rotating the platen 31 are attached to both ends of the platen 31, and the knobs 35, 35 are attached.
The sheet can be inserted into the platen 31 and set by rotating the platen 31 by manually rotating the platen 31.

Further, a platen gear 36 used for driving the ASF 2 and the like is fixed to the platen 31 on the side opposite to the line feed timing pulley, and an ink receiving unit 37 is attached to the line feed timing pulley side.

On the front side of the platen 31, a paper bail 40 fitted with a bail roller 39 operated by a sheet setting mechanism 38 described later is swingably arranged.

The bail roller 39 of this paper bail 40 is shown in FIG. 5B and FIG.
As shown in FIG. 5C, a piece wheel 39a having a plate thickness of 0.2 mm, a tooth interval of 7 ° 20 'and a tooth tip radius of 0.1 is integrally formed on the outer surface thereof. By forming the bail roller 39 in this way, the contact area between the bail roller 39 and the paper is extremely small, and ink stains do not occur due to the contact with the paper.

On the front side of the platen 31, a carriage 43 is slidably mounted on Japanese rods 41 and 42 arranged in parallel with the platen 31.

This carriage 43 is mounted on a platen via a space motor (carriage motor) 45, which is a stepping motor, via a space wire 48 stretched between a pulley (not shown) and pulleys 46, 47 fixed to the rotary shaft of the carriage motor 45. Moved parallel to 31.

Further, a pump unit 50 and a high-voltage power supply 51, which will be described later, for supplying ink to the carriage 43 are provided on the front side of this mechanical portion.

Further, a cover open switch 52 for detecting the opening / closing of the cover 5 is attached to the left side of this mechanical section.

Furthermore, a main board 53 and an interface board 54 that constitute a control section are mounted on the rear side of this mechanical section, and an ink jet unit board 55 on the front left and right sides.
And the preamplifier board 56 is attached.

On the back surface of the interface board 54, the DIP switches 25 and 26, the reset switch 27 and the like shown in FIG. 4 are attached.

FIG. 6 is a schematic configuration diagram of the carriage 43 and the pump unit 50.

The ink filled in the ink cartridge 62 is supplied to the ink tank 61 provided with the ink level sensor 60 of the pump unit 50.

Then, the ink in the ink tank 61 is pressure-fed by the pressure pump 63 to the accumulator 64, and is then sent from the accumulator 64 to the carriage 43 through the electromagnetic switching valve 65.

The accumulator 64 is provided with two pressure sensors 66 and 67 for detecting whether the internal ink pressure is higher than a predetermined value or lower than another predetermined value.

The ink sent from the pump unit 50 to the carriage 43 is sent to the ink jet head 73 through the heater 72 to which the filter 70 and the ink temperature sensor 71 are attached.

The ink sent to the ink ejecting head 73 is ejected from the nozzle, separated into ink particles at a constant cycle according to the vibration frequency of the electrostrictive oscillator 74, and ejected.

At this time, when the ink particles are not charged by the charging electrode 75, they are not deflected by the deflecting electrodes 76 and 77, go straight, are captured by the conductive gutter 78, and are returned to the ink tank 61 by the pump 68 of the pump unit 50. Be done.

Further, when the ink particles are charged by the charging electrode 75, they are deflected by the deflection electrodes 76, 77, and the carriage 43
When it is at the home position, it is collected by the ink receiving plate 81 of the ink receiving unit 37 (see FIG. 5), and when the carriage 43 is in the recording area, it collides with the paper.

In addition, in the portion of the carriage 43 where ink is likely to collect,
Electrodes 79, 79 for detecting ink leakage are installed.

Further, the ink receiving unit 37 is provided with a charge detection electrode 82 at a position where the ink collides in order to detect the presence of the ink.

The ink collected by the ink receiving plate 81 of the ink receiving unit 37 flows into the waste liquid tank 69 of the pump unit 50.

Further, when the electromagnetic switching valve 65 of the pump unit 50 is not energized, the ink outlet side of the accumulator 64 is closed, the filter 70 and the waste liquid tank 69 are in communication, and the ink pressure in the ink ejection head 73 is reduced. Filter until it drops to atmospheric pressure
About 70 ink flows into the waste liquid tank 69.

7 to 10 are views showing the sheet setting mechanism 38.

First, as shown in FIGS. 7 and 8, the paper bail 40 disposed in front of the platen 31 includes a bail lever 93 and a bail lever 94 fixed to a support shaft 91 that rotatably supports both ends thereof. It is attached to the platen 31 so that it can swing back and forth with respect to the platen 31.

A paper bail lever 92 for manually operating the paper bail 40 is fixed to one of the bail levers 93.

Below the paper bail lever 92, a rear end portion is rotatably supported by a support shaft 95, and a tension coil spring is provided.
A rotating lever 97 is provided which is urged to rotate in the direction of arrow S in FIG.

At the tip of the rotating lever 97, there are two-step projections 97 with which an engaging piece 92a formed at the tip of the paper bail lever 92 can be engaged.
a, 97b are formed.

Then, when the tip engaging piece 92a of the paper bail lever 92 is engaged with the lower side of the protrusion 97a of the rotating lever 97, the pulling force of the spring 96 urges the platen 31 to rotate and the paper bail 40 moves. Is held in a state where the bail roller 39 is pressed against the platen 31.

Further, when the paper bail lever 92 is rotated in the direction of arrow A in FIG.
The paper bail 40 is held at a position (retracting and holding position) where the bail roller 39 is separated from the platen 31 by overcoming the projection 97a of 7 and engaging with the lower side of the projection 97b.

By rotating the paper bail lever 92 to the platen 31 side from this state, the paper bail 40 returns to the state where the bail roller 39 is in pressure contact with the platen 31.

It should be noted that when the paper bail 40 is in pressure contact with the platen 31, it is pressed to the side of the rotation lever 97 by the side portion of the rotation lever 97 to be in the operating state, and the paper bail 40 is rotated. A micro switch 98 is arranged as a bail opening sensor that becomes inoperative when it is in the retracted holding position described above.

A release lever 100 is rotatably mounted on the support shaft 91 of the paper bail lever 92 as shown in FIG.

The release lever 100 is fixed with a protrusion 100a that engages with the lower end of the paper bail lever 92.
By rotating 100, the paper bail lever 9
2 can be rotated.

On the other hand, below the platen 31, as shown in FIG. 7, a curved plate-shaped deflector 101 for guiding the sheet P inserted from the direction of the arrow T along the platen 31 is arranged.

A plurality of holes are formed in the deflector 101 in the axial direction of the platen 31, and the pressing rollers 102 and 103 are arranged in two rows in the vicinity of these holes.

These pressing rollers 102 and 103 have one end fixed to the fixing portion 106.
It is held by a support plate 105 which is biased toward the platen 31 side by a plate-shaped spring 104 fixed to.

Further, below the support plate 105, a rotary shaft 108 to which a release piece 107 is fixed is rotatably arranged.
The release piece 107 is an engaging portion 105a formed at the lower end of the support plate 105.
Is engaged from above.

Then, as shown in FIG. 9, a rotary lever 109 having a protrusion 109a engaged with the lower end portion of the release lever 100 is fixed to the rotary shaft 108.

Therefore, when the release lever 100 is rotated in the direction of arrow B in FIG. 9, the rotary lever 109 is rotated, the rotary shaft 108 is rotated in the direction of arrow C, and the release piece 107 is supported by the support plate. Ten
Since the engaging portion 105a of 5 is pushed up, the support plate 105 is pushed down against the plate-like spring 104, and the pressing rollers 102, 1
03 separates from platen 31.

In this state, the release lever 100 is rotated in the direction opposite to the arrow B direction shown in FIG.
Since 107 rotates upward and separates from the engaging portion 105a of the support plate 105, the pressing rollers 102 and 103 are pressed against the peripheral surface of the platen 31 by the pressing force of the spring 104.

Further, as shown in FIG. 8, a paper sensor 111 as a paper presence / absence sensor for detecting whether or not there is paper on the platen 31 is fixedly attached to the fixed plate 112 on the obliquely rear side of the platen 31. A through hole 101a is formed in the deflector 101 corresponding to the paper sensor 111.

The paper sensor 111 is composed of a reflective photo sensor in which a light emitting element and a light receiving element are arranged in the axial direction of the platen 31.

Further, this paper sensor 111 is composed of press rollers 102,1.
It is located between 03. It is desirable to dispose the paper sensor 111 in such a position at a position where it is possible to detect whether or not there is a sheet at the printing position, but if this is done, ink stains easily occur,
This is also because it is difficult to select a position that can detect the presence or absence of paper without hindering the movement of the carriage 43.

Furthermore, in the lower front of the platen 31, the position shown in FIG.
As shown in FIG. 10, a plate-shaped card guide 114 made of a metal plate or a synthetic resin having substantially the same length as that of the platen 31 is arranged with both ends thereof held by holding plates 115.

The holding plate 115 has a rotating piece 117 having teeth 117a formed at its tip and is fixed to a rotating shaft 116 that is rotatably supported, and a tension coil spring 118 is interposed between the holding plate 115 and the fixed portion 106. I am disguised.

As a result, a card guide raising mechanism that raises the card guide 114 in conjunction with the rotation of the platen 31 is configured.

Then, as shown in FIG. 10, the connecting mechanism for connecting the card guide raising mechanism to the platen 31 is a rotary cylinder 120.
Is rotatably supported by a bearing (not shown), and a gear 121 fixed to the outer peripheral portion of the rotary cylinder 120 is meshed with a platen gear 36 fixed to the shaft of the platen 31.

Inside the rotary cylinder 120 and the gear 121, the sliding shaft 122
Is slidably inserted.

A gear 123 that meshes with the teeth 117a of the turning piece 117 of the card guide lifting mechanism is rotatably attached to one end of the sliding shaft 122, and a surface of the gear 123 that faces the rotary cylinder 120. The clutch plate 124 is fixed to the.

The other end of the sliding shaft 122 is connected to one end of a rotating lever 127, which has an intermediate portion rotatably supported by a shaft 126.

The other end of the rotating lever 127 has a protrusion 128 on the side.
Solenoid 1 through connecting piece 128 having a formed therein, tension coil spring 129, and connecting piece 130 having a protrusion 130a formed on a side portion thereof.
It is connected to 31 plungers 131a.

The rotating lever 127 and the connecting piece 128 are rotatably connected, and a part of the connecting pieces 128 and 130 and the spring 129 are connected.
Are housed in a cylindrical body 132.

As shown in FIG. 8, a swing plate 134 is fixed to the other end of the rotary shaft 116, and one end of a connecting plate 135 is rotatably supported by the swing plate 134. Further, a long hole 135a formed at the other end of the connecting plate 135 is fixed to the bail lever 94 by a pin.
The paper bail 40 is engaged with the platen 31 in association with the rotation of the rotation shaft 116, that is, the rise of the card guide 114.
It constitutes a mechanism to be slightly separated from.

Next, the paper set operation by the paper set mechanism 38 will be described. The manual operation of the paper bail lever 92 has been described above and will not be repeated.

First, when the solenoid 131 shown in FIG. 10 is actuated, the plunger 131a is pulled in the arrow D direction, the rotation lever 127 rotates in the arrow E direction, and the sliding shaft 122 moves in the arrow F direction. The clutch plate 124 fixed to the sliding shaft 122 is pressed against the rotary cylinder 120.

After the clutch plate 124 is pressed against the rotary cylinder 120, the plunger 131a of the solenoid 131 is further pulled by a predetermined amount to connect the connecting piece 130.
The protrusion 130a is separated from the cylindrical body 132 by a predetermined distance, and the clutch plate 124 is moved only by the pulling force of the spring 129.
Make sure that it is pressed against 0.

Thereby, the platen 31 and the card guide raising mechanism are connected.

Therefore, when the platen 31 is rotationally controlled, the platen 31
Is transmitted to the rotating piece 117 of the card guide raising mechanism through the platen gear 36, the gear 121, the rotating cylinder 120, the clutch plate 124, and the gear 123, and the rotating piece 117 rotates upward to rotate the rotating shaft. 116 rotates.

At this time, since the rear end portion 117b of the rotating piece 117 shown in FIG. 7 contacts the fixed portion 106 and the rotation of the rotating piece 120 is regulated by a predetermined amount or more, the rotating cylinder 120 and the clutch plate 124 are slipped to each other. one two Three
Does not rotate, and the rotating piece 117 and the rotating shaft 116 do not rotate more than a predetermined amount.

As a result, the holding plate 115 fixed to the rotary shaft 116 and the card guide 114 attached to the holding plate 115 rise to the position (paper guide position) shown by imaginary lines as shown in FIG. Platen 31 and paper bale 40 bale roller
It becomes possible to guide between 39 and.

At the same time, the rotation of the rotating shaft 116 is transmitted to the bail lever 94 via the connecting plate 135 as shown in FIG. 8, and the bail lever 94 swings in the arrow G direction, so that the paper bail 40 moves to the platen 40. Evacuate from 31.

It should be noted that the rotation of the paper bail 40 at this time does not deactivate the micro switch 98 for detecting the bail opening shown in FIG.

In this way the card guide 114 rises and the paper bail 40
Since the sheet retracts from the platen 31, the sheet P sent by the platen 31 and the press rollers 102 and 103 is
Guided with 01, and with card guide 114 paper bails 40
It is guided between the bail roller 39 and the platen 31 and is wound around the platen 31.

When the solenoid 131 is deactivated from this state, the rotation lever 127 returns to the state shown in FIG. 10, the adhesion between the clutch plate 124 and the rotary cylinder 120 is released, and the card guide 114 is held by the holding plate 115. The tensile force of the tension coil spring 118 interposed between the fixing portion 106 and the fixing portion 106 returns to the state shown in FIG.
Return to the state of contact with 31.

Thus, especially in ink jet printers,
Since it takes time for the ink to dry at the time of printing, it is not desirable to provide a paper guide on the front of the carriage at the time of setting the paper, and therefore it is not preferable to provide the card guide 114 as described above separately. The guide 114 is raised only during the paper setting to guide the paper between the platen 31 and the paper bail 40.

Needless to say, not only the ink jet printer but also other printers such as a character wheel printer and a thermal printer can be provided with the card guide as described above to guide the paper at the time of setting the paper.

Next, the details of ASF2 in FIG. 2 will be described.

FIG. 11A and FIG. 12 are a side sectional view of the ASF 2 and a perspective view of its main part.

The ASF 2 is provided with two paper stacking units 151 and 152 for loading paper and two paper discharge stacker units 153 and 154.

The hopper portions 151, 152 are press plates 15 for placing the paper P on a support plate 156 fixed to both side plates 155a, 155b.
7,158 and an intermediate press plate 159 are slidably mounted.

It should be noted that the support plate 156 is provided with an auxiliary back plate 160 when using a long sheet of paper, and the pressing plate 15
Paper guides 157a and 158a for guiding the side edges of the paper P are attached to the 7,158, respectively.

For the uppermost sheet of the bundle of sheets P loaded in these hoppers 151, 152, the pressing plates 157, 158 and 159 are pushed toward the sheet feeding roller 162 by a pressure mechanism (not shown). It is pressed against the peripheral surface of the paper feed roller 162.

The uppermost sheet P is rotated by the rotation of the sheet feeding roller 162.
The paper is fed in the direction of arrow H or arrow I through between the paper feed roller 162 and the friction pad 163 pressed against the paper feed roller 162.

The fed paper P is fed between the platens 31 of the printer 1 and the deflector 101 between the guide plates 165 and 166, and is guided by the platen 31 and the press rollers 102 and 103 while being guided by the deflector 101 and the card guide 114 as described above. Be delivered.

In addition, when the paper P is positioned at a predetermined printing position,
Predetermined printing is performed by ejecting ink particles from the ink ejecting head 73 on the carriage 43.

After that, the paper P is guided by the paper guide 170 and the paper guide 171, and the paper discharge rollers 173 and 17 having tooth-shaped projections formed on the circumferential surface.
Transported while being pinched by 4.

The paper guide 170 on the printing surface side of the paper P is the 11B
As shown in the figure, the portion of the sheet that comes into contact with the printing surface is cut out in the axial direction of the platen.

By forming the paper guide 170 in this manner, it is possible to prevent the paper guide 170 from rubbing the printing surface of the paper after printing and causing ink stains.

Then, the paper P that has passed the paper discharge rollers 173 and 174 is discharged according to the state of the switching guide 175 provided with elastic sheets (or brushes) 175a and 175a for giving the discharge directionality to the paper on both sides. The sheet is discharged to the sheet discharge trays 176 and 177 of the stacker unit 153 or the sheet discharge stacker unit 154.

In this case, when the paper is discharged to the paper discharge stacker unit 153, the print state on the paper can be seen, but the page is reversed, and when the paper is discharged to the paper discharge stacker unit 154, the print state on the paper cannot be seen. You can't, but you'll have to arrange them in page order.

Further, a manual paper feed slit 178 is formed on the lower surface of the rear of the paper discharge tray 176 of the paper discharge stacker unit 153 for manual paper feed with the ASF 2 attached.

Further, in the middle of the paper discharge tray 176, a presser plate 179 biased forward by a spring (not shown) is swingably mounted, and the paper discharged by the presser plate 179 is stacked. Slit paper for manual paper feeding
I try not to drop it in 178. An auxiliary back plate 180 is attached to the paper discharge tray 176.

Therefore, when performing manual paper feeding with the ASF 2 mounted, paper is inserted in the arrow J direction from between the slitter 178 and the presser plate 179 on the rear surface of the paper discharge tray 176.

As a result, the manual feed paper is guided by the guide plate 166 and the guide plate 1
It is guided by 81 and enters between the platen 31 and the press roller 102.

Therefore, after inserting the paper in this way, the automatic insertion switch 14 is pushed to instruct the automatic insertion.

FIG. 13 is a perspective view showing the drive mechanism of this ASF2.

First, the auxiliary plate 18 fixed to the side plate 155a at a predetermined interval.
A gear 186 which is meshed with the platen gear 36 of the platen 31 and is rotated by the rotation of the platen gear 36 in a state where the ASF 2 is mounted on the printer 1 is rotatably attached to the device 5.

A gear 188 meshing with the gear 186 is fixed to the auxiliary plate side end of the shaft 187 rotatably supported by the side plates 155a, 155b and the auxiliary plate 185.

A gear 190 is fixed to the shaft 187.
A gear 191 rotatably supported on the side plate 155a is meshed with 190, and a gear 192 is fixed to this gear 191.

The gear 192 has a support shaft 193 for the discharge roller 174.
Gear 194 supported via a one-way clutch (not shown)
Is biting.

On the other hand, the gear 191 includes a gear 1 rotatably supported by the side plate 155a.
The gear 196 is meshed with the gear 196 of the clutch mechanism 197 for the paper feed roller 162 of the hopper 151.

A gear 199 rotatably supported on the side plate 155a is meshed with a gear 198 of the clutch mechanism 197, and the gear 199 has a clutch mechanism 197 'for the paper feed roller 162 of the hopper portion 152.
The gear 198 'of is meshed.

The operation lever 200 is attached to the switching guide 175, and the side plate 155a is provided with a click mechanism 201 for holding the switching guide 175 at each switching position.

The clutch mechanism 197, as shown in FIGS. 14 to 16, has a drive disc 206 integrally attached with a gear 198 by being rotatably supported on a rotary shaft 205 supporting a sheet feeding roller 162. , And a clutch disk 208 supported on the rotating shaft 205 via a one-way clutch 207.

A pin 209 is planted in the drive disk 206, and a latch pole 210 is loosely fitted on the pin 209 so as to be rotatable with respect to the pin 209 and swingable as shown in FIG.

Further, this latch pole 210 is in pressure contact with the sliding contact surface 213 of the clutch disk 208 and in contact with the annular flange portion 214 by the torsion spring 211 attached to the pin 209 in a state where the clutch disk 208 is attached to the drive disk 206. It

On the other hand, as shown in FIG. 15, the clutch disk 208 has a first zone I on the left side region and a second zone II on the right side region of the sliding contact surface 213 with which the latch pole 210 slides. A portion 215 and a recess 216 are formed in the second zone II, respectively.

The protrusion 215 of the clutch disk 208 is shown in FIG.
As shown in FIG. 16, one end thereof is formed as a stepped end portion 217 in a state of being inclined, and the other end portion is formed as an inclined surface 218 that smoothly inclines to the sliding contact surface 213.

The recess 216 of the clutch disk 208 also has one end as a stepped end 219 and the other end as an inclined surface that smoothly transitions to the sliding contact surface 213.

A pin 200 is planted on the clutch disk 208 side of the drive disk 206, while
Corresponding to this, a stopper 221 made of a leaf spring is fixedly installed.

Also, as shown in FIG. 13, each clutch mechanism 197, 197 '
A brake mechanism 224 is arranged between them.

This brake mechanism 224 is used for each clutch disk 208, 208 '.
Brake pieces 225, 225 whose front end abuts on the brake surfaces 208a, 208a 'formed in the above are pivotally attached to a pin 226 implanted in the side plate 155a and urged in a separating direction by a tension coil spring 227.

On the other hand, the clutch mechanism 197 'also has a stepped end portion 21 of the latch pole 210' and the clutch disk 208 'as shown in FIG.
The clutch mechanism 197 has the same structure except that the relative position to 9'is different from that of the clutch mechanism 197. Therefore, the corresponding parts are denoted by the same reference numerals with a dash and detailed description thereof is omitted.

Next, the operation of these clutch mechanisms 197 and 197 'will be described.

First, in the clutch mechanism 197, when the platen 31 is rotated in the forward direction (line feed direction) for feeding the paper, the gear 198 is rotated in the X direction shown in FIG.

Thereby, the pin 220 of the drive disk 206 and the stopper 221 of the clutch disk 208 are engaged with each other, and the drive disk 206 and the clutch disk 208 are integrally rotated in the X direction shown by the arrow in FIG.

At this time, as shown in FIG. 16, the tip of the latch pole 210 of the drive disk 206 and the recess 21 of the clutch disk 208.
The distance from the stepped end portion 219 of 6 is maintained at a predetermined distance.

The position of the latch pole 210 with respect to the clutch disk 208 in this state is called a home position, and the angle between the stepped end 219 and the latch pole 210 is the space angle θ ₁
And

In addition, this drive disk 206 and clutch disk 2
When 08 is rotating in the X direction shown by the arrow, the rotation is not transmitted to the rotary shaft 205 by the one-way clutch 207, so that the paper feed roller 162 is also stopped and the paper P is not fed.

On the other hand, at this time, the clutch mechanism 179 'also similarly moves to the latch pole 210' of the drive disk 206 'as shown in FIG.
And the stepped end of the recess 216 'of the clutch disk 208'
219 'is maintained at a predetermined distance.

The position of the latch pole 210 'with respect to the clutch disk 208' in this state is called a home position, and the angle between the stepped end 219 'and the latch pole 210' is the space angle θ ₄ (θ ₄ > θ ₁ ). And

In this way, the rotation amount of the platen 31 for resetting (positioning to the home position) the clutch mechanisms 197, 197 'is, for example, 40 pulses (corresponding to one line) of the LF motor 32. The amount (hereinafter, simply described as the amount of rotation of the platen 31).

Therefore, when feeding the paper P in the hopper unit 151, the platen 31 of the printer 1 is rotated by a predetermined amount (for example, 280 pulses) in the reverse direction (backline feed direction) in which the paper is returned.

Accordingly, the drive disk 206 of the clutch mechanism 197
Rotates in the Y direction indicated by an arrow by an operating rotation angle θ ₂ (θ ₂ > θ ₁ ) corresponding to the rotation amount of the platen 31.

At this time, the clutch disk 208 is braked by the action of the brake mechanism 224 described above and stopped rotating.

Therefore, after the latch pole 210 makes a slight sliding contact with the first zone I of the clutch disk 208 by the rotation of the drive disk 206 in the direction of the arrow Y, the protruding portion 215 is shown as shown by the alternate long and short dash line in FIG. Up the slope 218 of.

Then, when the tip of the latch pole 210 falls from the stepped end 217 of the protrusion 215, the rotation of the drive disk 206 at the operating rotation angle θ ₂ ends.

From this state, the platen 31 is again moved forward by a predetermined amount (for example,
By rotating (80 pulses), drive disk
206 rotates in the X direction indicated by the arrow by the operating space angle θ ₃ according to the rotation amount of the platen 31.

At this time, since the clutch disk 208 is braked by the brake mechanism 224 and stopped without rotating, the tip of the latch pole 210 is guided by the step-like end 217 of the protrusion 215 to move the first portion of the sliding contact surface 213. Transition from zone I to second zone II falls into its recess 216 and engages its stepped end 219.

At this point, the rotation of the platen 31 is stopped and the rotation of the drive disk 206 at the working space angle θ ₃ is stopped.

The space angle θ ₁ , the operating rotation angle θ ₂ and the operating space angle θ ₃ have a relationship of θ ₂ = θ ₁ + θ ₃ .

Next, by rotating the platen 31 in this direction in the reverse direction (back line feed direction) by a predetermined amount (for example, 1540 pulses), the drive disk 206 rotates in the arrow Y direction.

At this time, the tip of the latch pole 210 is the clutch disk 2.
Since it engages with the stepped end 219 of the recess 216 of 08, the clutch disk 208 also rotates in the Y direction shown by the arrow.

Then, the rotation of the clutch disk 208 is transmitted to the rotary shaft 205 via the one-way clutch 207, and the paper feed roller 162
Is rotated, and the paper P in the hopper portion 151 is sent out.

At this time, the clutch mechanism 197 'has its latch pole 21
Since 0's only makes sliding contact with the first zone I of the sliding contact surface 213 'of the clutch disk 208', the paper feed roller 162 of the hopper 152 does not rotate and the paper P is not delivered.

In this case, the amount of rotation of the platen 31 is set to an amount that feeds the paper slightly more than the contact point between the platen 31 and the pressing roller 102.

Therefore, the paper P is loaded on the platen 31 and the press roller 102.
When it hits against the platen 31, the platen 31 is prevented from entering between the platen 31 and the pressing roller 102 by the reverse rotation of the platen 31, and a bulge is formed at the tip, and the tip of the platen 31
The posture is corrected so that the entire surface is in contact with.

Therefore, by rotating the platen 31 in the normal direction from this state, the sheet P is wound around the platen 31 as described above.

When the platen 31 rotates in the forward direction, the drive disk 206 rotates in the X direction shown by the arrow, so that the tip of the latch pole 210 is the end 2 of the recess 216 of the clutch disk 208.
The clutch disk 208 stops at a distance from 19, and the paper feed roller 162 also stops.

Then, the latch pole 210 returns to the home position due to the different rotation of the drive disk 206, the pin 220 and the stopper 221 are engaged with each other, and the clutch disk 208 rotates again, but the one-way clutch 207 causes the chuck portion 151 to rotate. The rotation is not transmitted to the sheet feeding roller 162 of.

Further, when the paper of the hopper portion 152 is fed, the platen 31 is rotated in the reverse direction by the rotation amount by which the drive disk 206 ′ shown in FIG. 13 rotates in the Y direction shown by the arrow by the operating rotation angle θ ₅ .

At this time, the drive disk 206 of the clutch mechanism 197 also rotates in the Y direction shown by the arrow, but the latch pole 210 passes over the protruding portion 215 of the clutch disk 208 that has stopped, and the first zone I of the sliding contact surface 213 is Y. The clutch disk 208 does not rotate but only slides in the direction.

After that, the platen 31 is rotated in the forward direction to rotate the drive disks 206, 206 ′ by the operating space angle θ ₃ and then the platen 31 is rotated in the reverse direction so that the latch pole 210 ′ of the clutch mechanism 197 ′ is rotated. Engage with the stepped end 219 'of the clutch disk 208' to engage the clutch disk.
208 'rotates in the Y direction shown by the arrow, the paper feed roller 162 of the hopper 152 rotates, and the paper P is delivered.

At this time, the drive disk 206 of the clutch mechanism 197 also rotates in the Y direction shown by the arrow, but its pin 220 crosses the stopper 221 of the clutch disk 208.
The 208 never rotates.

In this way, by controlling the rotation of the platen 31, the AS
The paper P can be selectively fed from each of the hopper portions 151 and 152 of F2.

It should be noted that the paper discharge roller 174 and the paper discharge roller 173 that follows this
Is driven to rotate only when the platen 31 rotates in the positive direction by the action of a one-way clutch (not shown) interposed between the support shaft 193 and the gear 194.

FIG. 18 is a block diagram showing the control unit of the printer 1.

This control unit includes an interface unit 251, a main control unit 252, various detection circuits, a driver, and the like.

First, the interface unit 251 is a microcomputer including an IF / CPU 253 including, for example, an 8-bit microprocessor (CPU), a ROM 254 storing programs and other fixed data, and a RAM 255 used as a working memory and a data memory. The system controls data transfer between the host system HTC and the main control unit 252.

The interface unit 251 also includes various switches and lamps provided on the operation panel 6 and a signal input / output I / O 257 with the buzzer 256.

Then, the status signals from the reset switch 11, the LF switch 12, the FF switch 13, and the automatic insertion switch 14 are fetched via the inverters 258 to 261 via the I / O 257, and the standby lamp 21 is turned on via the lamp driver 263. A signal is output, the buzzer 256 is sounded via the buzzer driver 264, and the status signal is taken in and the lighting signal is output from other switches and lamps via the I / F 265.

Further, the interface unit 251 is provided between the host I / F 266 and a host interface (I / F) 266 which controls transmission / reception of data, a busy signal BUSY, an initialize signal INS, etc. to / from the host HTC. It has an I / O 267 for information input / output.

Further, this interface unit 251 is
It consists of an ASF switch 26B, which is the switch No. 2 switch of DIP switch 26, which is manually operated by the operator depending on whether SF2 is used or not, a pull-up resistor 269, and a buffer 270.
An ASF identification circuit 268 is provided.

Then, the identification signal according to the state of the ASF switch 26B from the ASF identification circuit 268 is input to the I / O 267, and the host
Sending to HTC.

As described above, in this embodiment, the DIP switch A
Although the information indicating the presence or absence of SF is input, for example, a switch that operates when the ASF is attached to the printer may be provided, or the information indicating the presence or absence of ASF may be output by attaching or detaching the connector. Good.

In this case, as the configuration of the latter connector, for example, a connector having two open connector terminals (one for signal output and the other for ground) is provided on the printer side, and the two connector terminals are short-circuited. You may make it attach / detach the connector which has two pins.

Alternatively, the printer-side connector terminal may be only one for signal output, and a connector having a pin connected to the ground and a pin connected to this pin and corresponding to the signal output terminal of the printer may be attached or detached.

In the case of using this connector, for example, when a sensor for detecting paper breakage is provided in the ASF and this sensor signal is input to the printer, it is effective when some signal from the ASF is input to the printer. That is, since the ASF and the printer are connected by the connector, the information indicating the presence or absence of the ASF can be obtained at the same time when the connector of the ASF is attached to the connector of the printer.

Returning to FIG. 18, this interface unit 251 and host HTC
Is connected by the Centronics interface connector 28 described above.

The interface unit 251 is a programmable controller for transferring print data to and from the main control unit 252.
Peripheral / Parallel / serial converter (P / S) 272 and DM for parallel / serial conversion of I / O271 and print data
It is equipped with A (Direct Memory Access) 273.

The main control unit converts the print data from the host HTC stored in the RAM 255 by the DMA 273 into serial data by the P / S 272 according to the synchronization signal (SYN) input from the main control unit 252 to the I / O 271. Transfer to 252.

Also, the interface unit 251 sends and receives commands, responses, and the like related to printing and paper insertion control and the like to and from the main control unit 252 via I / Os 274 and 282.

Further, the interface section 251 includes the reset switch 27 as described above, and when the reset switch 27 is pressed, the initial reset signal is input only to each element of the interface section 251. I am trying to do it.

The initial reset signal from the reset switch 27 is an interrupt input to the main control section 252 and is not input as a reset signal.

On the other hand, the main controller 252 includes, for example, a MAIN / CPU 283 composed of an 8-bit microprocessor (CPU), a ROM 284 storing programs and other fixed data,
RAM2 used as working memory and data memory
The print control and the like are performed by a microcomputer system composed of 85.

Further, the main control unit 252 includes a distortion correction calculation circuit 286 and a ROM 287 storing a distortion correction table.

The distortion correction calculation circuit 286 receives print data transferred as serial data from the interface unit 251, corrects the print data based on the distortion correction calculation table stored in the ROM 287, and obtains the charging voltage data. The excitation basic pulse data is transmitted to the excitation voltage generation circuit 290 while being transmitted to the charging voltage generation circuit 289 via the D / A converter 288.

The charging voltage generation circuit 289 applies a charging voltage according to the charging voltage data from the distortion correction calculation circuit 286 to the charging electrode 75.

The excitation voltage generation circuit 290 applies an analog excitation voltage of a substantially sine wave corresponding to the excitation basic pulse data from the distortion correction calculation circuit 286 to the electrostrictive oscillator 74 for oscillation.

Further, the main control unit 252 includes an I / O 292, 293 that transmits and receives signals between the interrupt timer 291, each driver and the detection circuit, and a programmable peripheral I / O.
It is equipped with O294.

The LF motor driver 295 drives the LF motor 32 according to the line feed drive data from the main control unit 252.

The charge detection circuit 296 outputs, to the main control unit 252, a charge present signal that is output when the ink strikes the charge detection electrode 82.

The heater control circuit 297 drives and controls the heater 72 based on the detection signal from the ink temperature detection sensor 71 to control the ink temperature to a predetermined value while the heater ON signal from the main control unit 252 is being input.

The charge detection circuit 298 outputs a charge present signal to the main control unit 252 when the charged ink particles collide with the conductive gutter 78.

The paper detection circuit 299 outputs a detection signal indicating presence / absence of paper in accordance with the detection signal from the paper sensor 111 to the main control unit.
Output to 252.

The ink level detection circuit 300 outputs a detection signal indicating presence / absence of ink to the main control unit 252 according to whether or not the ink is in contact with the ink level sensor 60.

The ink high pressure detection circuit 301 and the ink low pressure detection circuit 302 respectively detect when the ink pressure is higher than a predetermined value set in advance in accordance with the detection signals of the pressure sensors 66 and 67, and when the ink pressure is lower than another predetermined value set in advance. Then, a detection signal indicating the high ink pressure and the low ink pressure is output to the main control unit 252.

The ink detection circuit 303 outputs a detection signal indicating ink leakage when ink is present between the electrodes 79, 79 to the main control unit 25.
Output to 2.

The valve driver 304 switches and drives the electromagnetic switching valve (valve) 65 according to a valve switching instruction signal from the main control unit 252.

The pump driver 305 drives the pump 63 according to a pump drive instruction signal from the main control unit 252.

The high voltage generation circuit 306 applies a deflection voltage to the deflection electrode 76 according to the deflection instruction signal from the main control unit 252.

The home position detection circuit 307 outputs a detection signal indicating that the carriage 43 is located at the home position to the main control unit 252 in response to a detection signal from the home sensor 308, which is not shown in the description of the mechanical section.

The cover open detection circuit 309 outputs a detection signal indicating cover open / close to the main control unit 252 according to the state of the cover open switch 52.

The SP motor driver 310 drives the carriage motor 45 according to the carriage motor drive data from the main control unit 252.

The paper bale open detection circuit 311 outputs a detection signal indicating the paper bail open to the main control unit 252 according to the state of the micro switch 98.

The solenoid driver 312 drives the solenoid 131 according to a solenoid drive signal from the main control unit 252.

The relationship between each circuit of the control unit and the print board is as follows.

The main board 53 has a main control unit 252, a charging voltage generation circuit 289, an LF motor driver 295, a paper detection circuit 299, a home position detection circuit 307, an SP motor driver 310, a paper bail open detection circuit 311, and a solenoid driver 312.
The interface board 54 includes an interface section 251 and an operation section circuit.

Further, the ink jet unit board 55 has a heater control circuit 297, an excitation voltage generation circuit 290, and an ink level detection circuit.
Includes 300 to pump driver 305, preamp board 56
Includes charge detection circuits 296 and 298.

Next, the operation of this embodiment configured as described above will be described.
The description will be made also with reference to FIG.

First, the main control unit 252 starts executing the initialization process shown in FIG. 19 when the power is turned on.

In this initialization processing, initialization processing such as pointer saving and register clearing is executed.

After that, the carriage 43 is positioned at the home position, and whether the ink leaks or the ink high pressure is determined, and if the ink leaks or the ink high pressure, the process proceeds to error processing.

If the ink is not leaked or the ink pressure is not high, it is determined whether or not the ink pressurizing pump 63 and the ink collecting pump 68 are driven to maintain the ink low pressure by the predetermined time and whether the ink low pressure is reached after the predetermined time. Or not.

At this time, if the ink pressure is low even after the lapse of a predetermined time, the process proceeds to error processing, and if the ink low pressure disappears within the predetermined time or after the lapse of the predetermined time, that is, when the ink pressure rises to a predetermined value or more, the electromagnetic switching valve ) 65 is energized to turn on the electrostrictive oscillator 74, turn on the heater 72, and then wait for 60 seconds.

Until the 60 seconds have elapsed, the ink jet head 73
Ink is ejected from the charged electrode 75 and is separated into ink particles at a constant cycle approximately in the middle of the charging electrode 75.
Clash with 78.

Then, when 60 seconds have elapsed, the process shifts to the main routine.

This main routine will be described with reference to FIG.

First, after performing the phase search process, the deflection amount setting process is performed.

In the phase search process, the charging voltage is applied to the charging electrode 75 in the state where the deflection voltage is not applied to the deflection electrode 76, and the phase of this charging voltage is sequentially shifted until the charged signal is input from the charge detection circuit 298. , The phase when the charged signal is input is the optimum phase.

In this way, the optimum phase of the charging voltage is searched, and thereafter, the charging voltage of the searched phase is applied to the charging electrode 75 until the phase searching process is executed again.

Further, in this deflection amount setting process, with the carriage 43 positioned at the home position, the standard deflection voltage of the deflection maximum step is applied to the charging electrode 75, the detection signal of the charge detection circuit 296 is referred to, When the result of this detection is that there is no charge, the charge voltage is sequentially increased by a predetermined amount, and when the result is that charge is present, the charge voltage is sequentially increased for each minimum unit.

Then, the correction amount is calculated based on the difference between the charging voltage when the charge is changed to the non-charged state and the standard charging voltage, and the charging voltage of each deflection step during printing is calculated.

After executing the phase search process and the deflection amount setting process in this way, a standby completion instruction is sent to the interface unit 251. As a result, the interface section
251 intermittently energizes the buzzer 256 three times, clears the busy signal BUSY to the host HTC, and turns off the standby lamp 21.

Then, after the timer 291 is set to 80 seconds, the sensor check processing for checking the state of the sensor (including the switch) is executed.

After that, data input from the interface unit 251 is permitted, and if there is data input, it is determined whether the data is print data or command data. If it is print data, print processing is executed. After executing the command processing, the ink jet stop determination counter (register) is reset.

Then, if there is no data input from the interface unit 251, it is as it is, and if there is data input, after the above-mentioned counter reset, it is determined whether or not the 80 sec timer is timed up.

At this time, if the time is not up, the process returns from the sensor check process to the data input determination from the interface unit 251, and is repeatedly executed until 80 sec has elapsed from the completion of the print preparation (standby).

On the other hand, when the timer times out, that is, when there is no input from the interface unit 251 for 80 seconds after the standby is completed and there is no other sensor check process, the ink ejection stop determination counter is incremented (+1), It is determined whether or not the value of the counter is "7".

At this time, if the counter value is not "7", the ejection waste liquid process of ejecting ink to the ink receiving plate 81 of the ink receiving unit 37 is executed for 2.5 seconds while the carriage 43 is positioned at the home position. After that, the process returns to the phase search process.

If the value of the counter is "7", it means that the waiting for data input from the interface unit 251 has continued for 560 seconds (80 × 7), so after the temporary stop processing, the processing returns to the phase search processing. .

Next, the bail check processing in the sensor check processing of this main routine will be described with reference to FIG.

First, it is determined whether or not the paper bail 40 is in the open state, and if the paper bail 40 is in the open state, the interface unit 251 is instructed to turn on the bail open lamp 20.

Thereafter, the solenoid 131 of the sheet setting mechanism 38 is turned on until the paper bail 40 is closed.

Then, when the paper bail 40 is closed, the solenoid 131 is turned off, and the interface unit 251 is instructed to turn off the bail open lamp 20.

This bail check processing is for carrying out a paper manual set in which the printer is stopped and the platen 31 is manually operated to set the paper.

That is, in this printer, normally, as will be described later, the paper set is automatically performed by the operation of the automatic insertion switch 14 or the paper feed command from the host.
You may want to manually operate to set the paper.

By the way, with this printer, the platen
The card guide 114 is raised in association with the rotation of 31 to guide the paper to the platen 31.

Therefore, when the paper bail 40 is opened after the standby is completed, it is determined that the sheet is a manual set, and the solenoid 131 is operated to connect the platen 31 and the card guide raising mechanism for raising the card guide 114 as described above. To do.

Therefore, even when the sheet is manually set (manual insertion), the card guide 114 is raised to the sheet guide position by manually rotating the platen 31, so that the sheet set becomes easy.

When the paper bail 40 is opened, data reception is prohibited, the printer is stopped, and the paper bail 40 is closed again, and then a recovery process (not shown) is performed.

Next, the cover check processing in the sensor check processing of the main routine will be described with reference to FIG.

First, it is determined whether or not the cover 5 is in the open state, and when the cover 5 is in the open state, the interface section 251 is instructed to turn on the cover open lamp 19,
This routine is repeatedly executed until the cover 5 is closed.

That is, when the cover 5 is opened after the completion of the standby, the ink jetting state is kept in standby and the timed stop is not performed, so that the aging ink jetting for a long time can be easily performed.

Next, the temporary stop process of the main routine will be described with reference to FIG.

First, the interface unit 251 is instructed to pause. As a result, the interface unit 251 causes the buzzer 256 to
Is activated once and the standby lamp 21 is controlled to blink.

After that, after resetting the temporary stop determination counter, the electromagnetic switching valve 65 (valve) is de-energized and each pump 63, 6
8 is turned off, and the electrostrictive oscillator 74 is turned off.

Then, in this state, it waits until a reset input is made from the interface section 251, that is, until the reset switch 11 of the operation panel 6 is pressed or the initialization signal INS from the host HTC is input.

Then, when the reset switch 11 on the operation panel 6 is pressed or the initialization signal is input from the host HTC and the reset instruction is input from the interface section 251, the pumps 63 and 68 are turned on. The electromagnetic switching valve 65 (valve) is energized to turn on the electrostrictive oscillator 74, and the interface unit 251 is instructed to turn on the standby lamp 21.

After that, the system waits for 30 seconds in this state, and when 30 seconds have elapsed, the process returns to the phase search process of the main routine shown in FIG.

Next, the interface unit 251 starts executing the initialization process shown in FIG. 24 when the power is turned on and when the reset switch 27 is turned on.

First, initialization processing such as register saving is executed.

After that, the state of each switch of the DIP switches 25 and 26 is read, and the read data is stored in the internal RAM.

That is, the interface unit 251 executes the initialization process not only when the power is turned on, but also when the reset switch 27 is turned on.
As described above, 2 executes the initialization process only when the power is turned on, and then shifts to the main routine.

This is to shorten the time from the mode change to the standby completion when the mode specified by the DIP switch, such as the presence or absence of ASF, is changed because the state of the DIP switch is read and stored during the initialization process. .

That is, in the ink jet printer, since a predetermined time (60 seconds in this embodiment) is required until the preparation for printing is completed after the power is turned on as described above, the power switch must be turned off every time the setting mode is changed. However, the efficiency cannot be improved because printing cannot be performed for a predetermined time each time.

On the other hand, by providing a switch for instructing the initialization of only a part (interface part) separately from the initialization when the power is turned on like this printer, the setting mode can be set without turning off the power. It is possible to make a change, and it is possible to shorten the time until the printable state after changing the mode.

It should be noted that it is possible to provide a routine that periodically monitors the status of the DIP switch, etc. in the main routine, but in this case the number of processes in the main routine will increase accordingly, so this printer will be set first. I try to capture all modes.

Next, the main routine of the interface unit 251 will be described with reference to FIG.

First, it is determined whether or not there is a reception from the main control unit 252, and when data or the like is received from the main control unit 252, a reception process is performed to perform processing according to the received data.

In this reception processing, for example, upon receipt of the standby instruction or the temporary stop instruction described above, output of the busy signal BUSY to the host HTC, output stop, lighting of the standby lamp 21, blink control, or drive control of the buzzer 256 is performed.

It should be noted that this receiving process should be performed by an interrupt rather than the main routine.

Then, if there is no received data from the main control unit 252, it is determined whether there is received data from the host HTC, and when data is received from the host HTC,
A print process or a command process is executed depending on whether the received data is print data or command data.

In the printing process, the received print data is stored in the reception buffer (RAM255), and for example, a print command is output to the main control unit 252 every time print data for one line is received, and thereafter, the print data is printed by the DMA 273. The data is transferred to the main control unit 252.

In command processing, the received command data is
When the LF (line feed) command and the FF (form feed) command are used, the paper feed process is performed. When the paper feed command (feed command) is used, the paper automatic insertion process including the paper feed control from the ASF2 is performed. When it is a command, the command processing corresponding to the command is performed.

Furthermore, when there is no received data from the host HTC,
The status of each switch on the operation panel 6 is monitored, and when the LF switch 12 or the FF switch 13 is pressed, the paper feed process is performed, and when the automatic insertion switch 14 is pressed, the paper automatic control including the paper feed control from the ASF 2 is performed. Insertion processing is performed, and when another switch is pressed, processing corresponding to that switch is performed.

Next, the paper automatic insertion processing in this printer will be described. The process of manually inserting the paper has been described above, and will not be described here.

First, when this printer is not equipped with ASF2 (when not in use), paper is manually fed for each sheet.

Therefore, when the print data is sent from the host to the printer, for example, after the print data for one page is transferred, the print data is sent until the printer manually feeds and the busy signal is released. Need to wait for the transfer.

On the other hand, when the ASF2 is installed (when available), the host side can continuously transfer a plurality of data for each page with a paper feed command at the beginning. .

Also, if a paper feed command or paper discharge command is output to the printer when the ASF2 is not installed, it becomes an invalid code, so it is ignored every time the paper feed command or paper discharge command is sent, and the host It is necessary to carry out processing to convey that fact.

Therefore, this printer is equipped with the ASF switch 26B indicating the presence or absence of ASF2 as described above, and the status signal of this ASF switch 26B, that is, the identification signal indicating the presence or absence of ASF2 is sent to the printer 1.
Not only the interface unit 251 of the above, but also the host HTC.

Therefore, the host HTC receives this ASF identification signal and
When F2 is present, the paper feed and paper discharge commands are output and the print data is continuously transferred, whereas when ASF2 is not present, the paper feed and paper discharge commands are not output and the print data is transferred only once. Control is switched as desired.

The processing at the time of printing on the host side will be described with reference to FIG.

First, when the host HTC is instructed to print,
For example, in the case of a word processor, printer preparation processing is performed to set conditions necessary for printing such as the print document name, the print range, the presence or absence of pagination, and the number of print copies.

After that, the printer check processing is performed to check the information indicating the presence or absence of ASF2 input from the printer 1, the busy signal, etc., and when the printer 1 enters the ready state and printing becomes possible, the data transfer to the printer 1 is started. To do.

At this time, when the printer 1 has the ASF 2, the paper feed command is added to the head of the print data of one page, and the paper feed command and the print data are transferred to the printer 1 in this order. And
After the transfer of the print data of one page is completed, it is determined whether or not there is a continuation page. If there is a continuation page, the printer 1 adds the paper feed command to the beginning of the print data of the next page. Transfer to.

As described above, when the printer 1 has the ASF 2, the print data can be transferred with the paper feed command, so that the print data can be continuously transferred.

On the other hand, if the printer 1 does not have the ASF2, it is not possible to continuously feed the printer 1, so the print data of one page is transferred.
Then, the printer waits until the paper is set by the manual paper feed and becomes the printer ready. When the printer ready, the transfer of the print data of the next page is started.

In this way, the host side controls whether to send the print data with the paper feed command or not without the paper feed command depending on whether the printer has an ASF or not. .

By thus sending the information indicating the presence or absence of ASF to the host side as well, the host side can give an appropriate control command to the printer according to the presence or absence of ASF.

Further, in this embodiment, the state of the ASF switch 26B is output as it is to the host HTC via the buffer, but the interface unit 251 outputs the information indicating the ASF / ON / OFF read during the initialization processing. It can also be sent to the host HTC. By doing so, one signal line can be reduced.

Therefore, the automatic paper inserting process on the printer side will be described with reference to FIG. 27 showing the process executed by the interface unit 251 and FIGS. 28 to 33 showing the process executed by the main control unit 252.

First, as described above, the IF / CPU 253 of the interface unit 251 receives the first command when the automatic insertion switch 14 of the operation panel 6 is pressed and when the paper feed command (paper feed command) from the host HTC is received. 27 Start the execution of the process shown in FIG.

Then, the state (ON / OFF) of the ASF switch 26B is checked by referring to the memory stored in the initialization processing.

At this time, if the ASF switch 26B is OFF, manual feeding will be performed.
2 is "Check command with paper" for MAIN / CPU283
Is output.

Therefore, the MAIN / CPU 283 executes the command with paper command check process shown in FIG. 28 to check the vapor sensor 111, and if there is paper, the response is “with paper” and if there is no paper, the response is “without paper”. Respectively to the IF / CPU 253.

If the response from the MAIN / CPU 283 is "paper present", the IF / CPU 253 determines that printing is still in progress because the paper is wrapped around the platen 31, and terminates this paper automatic insertion process. To do.

On the other hand, if the response from the MAIN / CPU 283 is not "with paper", the "LE forward command" is output to the MAIN / CPU 283, the "auto set command" is output, and then the automatic insertion switch 14 Wait until the switch is released, and when the switch is released, the automatic paper insertion process is completed after 1.5 seconds.

Therefore, when the MAIN / CPU 283 receives the "LE forward command", it executes the LE forward command processing shown in FIG. 29 to set the internal status, and when it receives the "auto set command", the The autoset command processing shown in the figure is executed.

In this auto set command processing, after first accepting other command interrupts, it is determined whether or not the carriage 43 is in the home position, and if it is not in the home position, the carriage return operation is performed. Return the Carriage 43 to the home position.

Then, with the carriage 43 positioned at the home position, it is determined whether or not an operation error has occurred, and if an operation error has occurred, the operation waits until it is eliminated.

And if the operation error disappears, the platen
For example, the operation of rotating the 31 (LE motor 32) in the forward direction (forward direction) by 200 pulses (steps) is started, and while the platen 31 is rotated by 200 pulses in the forward direction, the paper sensor 111 is checked every 1 pulse rotation. Then, it is determined whether or not there is paper.

At this time, if the paper is not present even if the platen 31 is rotated by 200 pulses in the forward direction, the automatic paper insertion processing is ended as it is.

That is, when the automatic insertion switch 14 is pressed without setting the paper in the printer during manual paper feeding, or when the paper is set and the automatic insertion switch 14 is pressed but the paper jams in the middle, all the paper is inserted. It is useless to perform the paper feeding operation (rotation of the platen).

Therefore, if the paper does not become available even though the platen has been rotated by the amount that should have the paper, the paper insertion operation is terminated at that point and the next processing is immediately performed without continuing the wasteful operation. Transition.

In this case, the paperless lamp 16 is turned on and the buzzer 25
Beep 6 to inform the operator that there is no paper (including the occurrence of a jam).

On the other hand, when paper becomes available while the platen 31 rotates 200 pulses in the positive direction, the counter for counting the rotation amount is cleared once, and then the platen 31 is newly rotated by 232 pulses in the positive direction. Let the solenoid 131
Is turned on and waits for the time required for the operation (for example, 50 msec).

As a result, as described above, the card guide 114 moves along with the rotation of the platen 31 to ascend to the position for guiding the sheet.

Therefore, the platen 31 is further rotated to feed the paper, and the solenoid 131 is turned off when the paper of 560 pulses is fed.
After waiting for msec, the autoset command processing is terminated.

Next, if the ASF switch 26B is in the ON state, the IF / CPU 253 can perform both automatic paper feeding and manual paper feeding, and therefore first outputs the "paper check command" to the MAIN / CPU 283. .

As a result, the MAIN / CPU 283 executes the check command process with paper shown in FIG.
Return to 53.

Therefore, when the IF / CPU 253 receives the response of "paper is present" from the MAIN / CPU 283, there is paper remaining on the platen 31 and a paper jam occurs when the next paper feeding is performed.
Output the "paper ejection command" to IN / CPU283 and
・ Wait until the CPU 283 enters the ready state.

Therefore, the MAIN / CPU 283 executes the paper discharge command process shown in FIG. 33 to move the platen 31 to one line (for example, 40 pulses).
Rotate in the forward direction to determine whether 4000 pulses (100) lines have been sent, and whether paper has run out during that time. The process of rotating 31 by one line is repeated.

Then, if the paper runs out while the platen 31 is rotated by 4000 pulses, the process is ended by further rotating the platen 31 in the positive direction by 1200 pulses.

If the platen 31 does not run out of paper even when it is rotated by 4000 pulses, the discharge command processing is ended at the time of sending 4000 pulses. This is because, for example, in the case of continuous forms, the operation does not end and is repeated endlessly.

In this way, when the MAIN / CPU 283 finishes the paper ejection command processing and enters the ready state, the IF / CPU 253
Output "Paper feed command" to U283 and wait until MAIN / CPU283 becomes ready state.

Therefore, when the MAIN / CPU 283 receives this "paper feed command", it executes the paper feed command processing shown in FIG. 31 to feed paper from the APF2's hopper section 151, as described above. After rotating 31 by 280 pulses in the reverse direction, this time by rotating by 80 pulses in the forward direction, the clutch mechanism 197 of the paper holding part 151 is connected, and the paper feed roller 162 and the platen 31 are connected.

Therefore, this time, the platen 31 is rotated in the opposite direction by 1540 pulses.

As a result, as described above, the paper is sent to a space between the platen 31 and the press roller 102, and the posture of the paper is adjusted.

Therefore, the process proceeds to the auto set command process shown in FIG. 30 and the paper is inserted. Therefore, even if the platen 31 is rotated by 200 pulses at this time and the paper is not present, the paper insertion operation is ended at that time.

That is, when the paper ejection operation is performed, the platen
Since the clutch mechanism 197 is reset (pre-initialized) by the forward rotation of 31, the paper feeding operation is immediately performed without performing the pre-initialization operation described later.

Next, if the response from MAIN / CPU 283 is "no paper", IF / CPU 253 outputs a "pre-initial command" to MAIN / CPU 283, and waits until MAIN / CPU 283 enters the ready state. To do.

Therefore, when the MAIN / CPU 283 receives the "pre-initial command", it executes the pre-initial command processing shown in Fig. 32 to rotate the platen 31 in units of 40 pulses (equivalent to one line), and each time there is paper. Or not.

Then, when there is paper before repeating the rotation of the platen 31 in 40 pulse units 16 times, the paper is not fed by the ASF2 but is manually fed by the operator.
Immediately, the process proceeds to the autoset command process shown in FIG.

On the other hand, if there is no paper even if the platen 31 is rotated 16 times, it can be determined that the paper is fed from ASF2.
After shifting to the paper feed command processing shown in FIG. 31 to feed paper from ASF2, the paper set operation is performed.

In other words, during pre-initial operation (paper preparation operation) to reset the clutch of ASF2 to make it ready for paper feeding, if there is paper, it is judged as manual paper feeding, and the automatic set operation is performed as it is. If there is no paper even after the feeding operation and the pre-initialization operation is completed, it is judged as automatic paper feeding and the paper feeding operation from ASF2 is performed.

The automatic paper insertion operation of this printer is summarized as follows: (1) As a result of determining the presence or absence of ASF, when there is no ASF, it is determined that the paper is manually fed, and at that time, it is checked whether or not there is paper on the platen. If there is paper, the automatic paper insertion operation is terminated, and if there is no paper, the automatic set operation is performed.

(2) As a result of the determination of the presence / absence of the ASF, when the ASF is present, there are cases of automatic sheet feeding and manual sheet feeding.

Therefore, first check whether there is paper on the platen, and if there is paper, perform a paper ejection operation to forcibly eject that paper, and then perform the ASF paper feeding operation to eject the paper from ASF. The paper is fed, and then the paper is automatically set to automatically set the paper on the platen.

On the other hand, if there is no paper, the pre-initial operation that makes the ASF ready for paper feeding is performed. At the same time, it is determined whether the paper is manually fed or automatically fed. If it is automatic paper feeding, the paper automatic setting operation is performed after the ASF paper feeding operation.

Next, the paper feed control after line printing in this printer will be described with reference to FIG. 34 and subsequent figures.

Since the ink jet printer uses water-based ink, it takes a predetermined time for the ink to be printed on the paper and dried.

Therefore, in order to increase the throughput of the printer, the time until the printing surface contacts the mechanical mechanism of the paper transport path is adjusted to the ink drying time until the paper is stored in the stacker after printing. Control is needed.

Here, considering the mechanical mechanism that comes into contact with the printed surface of the paper after printing to generate ink stains, in this printer, the bail roller 39 of the paper bail 40 is used as shown in FIGS. 5B and 5C. ASF2 paper ejection guide plate 17
Since 0 is formed by cutting out the contact area with the printing surface as shown in FIG. 11B, these bail roller 39, guide plate 1
The ink 70 can be excluded from the mechanical mechanism that generates dirt.

After all, in this printer, it is the discharge roller 173 of the ASF2 that comes into contact with the printing surface of the paper that needs attention in terms of drying the ink.

Therefore, the time until the paper reaches the paper discharge roller 173 from the print position by the carriage 43 is managed. In the case of the printer 1 and ASF2, the distance from the printing position of the carriage 43 to the paper discharge roller 173 of ASF2 is "13.5.
X 1/6 inch ".

Therefore, a different example of the paper feed process (print end process) at the end of line printing executed by the interface unit 251 will be described with reference to FIGS. 34 and 35.

In this embodiment, as will be apparent from the following description, the interface unit 251 determines whether or not the interface unit 251 has just formed an image according to the present invention, and an automatic sheet feeder (ASF). It functions as a discriminating unit (second discriminating unit) for discriminating whether or not the sheet is mounted and a paper feed control unit.

This print end processing is executed when the printing of one line of print data is completed and when the LF and FF commands from the host side are received. The paper feeding process when the LF switch 12 or the like is pressed is different, but the description thereof is omitted.

First, in the print end processing shown in FIG. 34, it is determined whether or not the line has just been printed (immediately after the end of printing), that is, whether the line has been printed before the line feed operation (paper feed operation).

At this time, if it is not immediately after the end of printing, the LF number (paper feed amount) is immediately sent (out) to the main control unit 252, and then the forward LF is set.

Accordingly, the main control unit 252 drives and controls the line feed motor 32 to rotate the platen 31 by the set number of LFs in the forward direction to feed the sheet.

On the other hand, immediately after the end of printing, the signal ▲ ▼ (which is one of the data sent from the I / O 274) to the main controller 252 is reset.

After that, in the initialization process, the ASF switch 26B status (ON / OFF)
Check the memory that stored the ASF switch 26B
Determine whether it is ON (ASF / ON).

At this time, if the ASF is not ON, the ASF is not installed and the paper feeding operation is immediately executed.

On the other hand, if the ASF is ON, since the ASF is installed, it is determined whether or not the paper feed amount (line feed amount: LF number) is “540 steps” or more. The "540 steps" is the number of steps (paper feed amount) from the printing unit (printing position by the carriage 43) to the paper discharge roller 173 of the ASF2.

Then, if the LF number at this time is not more than "540 steps", the paper feeding operation is immediately performed as described above.

On the other hand, if the LF number is “540 steps” or more,
Wait until Carriage 43 returns to the home position.

After the Carriage 43 returns to the home position, it waits for 4.5 seconds (4.5 seconds wait) and 4.
The paper feed operation starts after 5 seconds.

In this way, in this print end processing, ASF is turned on immediately after print end (line print end),
When the LF number (paper feed amount) is "540 steps" or more, the start of the line feed operation (paper feed operation) is delayed by "4.5" seconds.

In other words, here, the paper feed time management after printing one line is set to 1
This is done by delaying the paper feed operation for 4.5 seconds after line printing is completed. It should be noted that the waiting time and the paper feed amount for setting the waiting time are determined according to the specifications of the printer, and in this printer, ink stains are not generated by setting the above values.

On the other hand, when the line feed operation is not a line feed operation just after the printing is finished, the print surface is not contaminated and the paper feed operation is immediately started.

In addition, even if a line feed immediately after the end of printing (end of line printing), AS
When the F / ON is not set, that is, when the ASF2 is not installed, the printing surface is not contaminated by the paper discharge roller 173 of the ASF2 as described above, and thus the paper feeding operation is immediately started in this case as well. .

Furthermore, the line feed immediately after the end of printing (end of line printing), and even if ASF2 is installed, the paper feed amount (LF amount) is "54".
When it is less than "0 step", the printing position of the paper does not reach the paper discharge roller 173 of the ASF2, and therefore the paper feeding operation is performed immediately also in this case.

In this way, in this line feed processing, the start of the paper feed amount operation is controlled based on the paper feed amount (LF number), so the delay control is performed only when it is necessary to delay the start of the paper feed operation. Since the delay control is not performed when it is not necessary, the time required for line feed is shortened and the printing throughput of the printer is improved.

Also, in the above print end processing, it is switched whether to control based on the paper feed amount depending on whether ASF is installed or not, and the paper feed operation is started only when ASF that may cause paper stain is installed. I'm trying to delay.

As a result, the line feed operation is not unnecessarily delayed until the ASF is installed, that is, when the paper is not stained, and the throughput is further improved when the ASF is not installed.

Next, in the print end processing shown in FIG. 35, the print end processing shown in FIG. 34 described above is executed until the processing immediately after the print is ended, the signal reset processing and the ASF / ON judgment processing. Is the same as in.

Then, when the ASF is ON, it is determined whether or not the LF number is "100 steps" or more.

At this time, if the LF number is not more than "100 steps", the paper feeding operation is immediately performed.

On the other hand, if the LF number is 100 steps or more,
After waiting until the carriage 43 returns to the home position, it is determined whether or not the LF number is “540 steps” or more.

At this time, if the number of LF is "540 steps" or more, "4.5
After waiting for "seconds", the paper feeding operation is started.

On the other hand, if the number of LF is not "540 steps" or more, that is, if the number of LF is "100 steps" or more and less than "540 steps" (100≤LF number <540), the delay time (wait time) ) TD is calculated by calculating TD = 10 × (number of LFs) −1000 (1), the calculated delay time TD is set in the wait timer, and the paper feed operation is started.

However, "10" in the above formula (1) is a multiplier that makes the delay time (wait time) at 540 steps about 4.5 seconds (4.5 seconds in this formula), and "1000" is one line. This is the time required for printing (line printing time).

That is, in this print end process, if the LF number is “540 steps” or more, the wait time (delay time) of “4.5 seconds” is set as in the case of the print end process described above. Even if it is less than 540 steps, "1
When it is "00 step" or more, the wait time (daylight time) is set according to the paper feed amount.

Here, when the above equation (1) is generalized and shown, the line print time is B, the paper feed amount (line feed amount) is N, and the mechanical contact part that causes ink stains on the print surface of the paper from the print part When the paper feed amount (number of steps) until is set to NLT, the delay time T
Set D to TD = AN-B. A is a multiplier, and A = (maximum delay time TDmax + B) / N.

Next, the print end process will be specifically described with reference to FIG.

First, for example, as shown in FIG. 36, the first line is printed from the predetermined step, and the first to fourth lines are each printed with a 40-step line feed, and after printing the fourth line.
A 300-step line feed is performed and the fifth line is printed. After the fifth line is printed, a 300-step line feed is performed and the sixth line is printed.

In this case, if the delay time is not provided, the first to sixth lines, which are the print lines of the paper, are the discharge rollers 173 of ASF2.
The time to reach is as follows.

However, the LF speed in this printer is
2.5msec (2.5ms / step), settling time after the end of LF operation
50msec, line printing time B is 1sec. The line printing time B includes a time required for carriage return (including stable time) and a time required for feeding 40 steps of LF (including stable time).

That is, in this case, the first to fourth rows are respectively the fifth row.
The line reaches the discharge roller 173 at the time of LF after printing, the fifth line reaches the discharge roller 173 at the time of LF after printing the sixth line, and the sixth line reaches the discharge roller 173 at the time of LF after printing. Will be done.

Therefore, after the printing of each print line to
The time to reach 173 is 4B + (300 x 2.5ms + 50ms) + 80 x 2.5ms = 5.0sec 3B + (300 x 2.5ms + 50ms) + 120 x 2.5ms = 4.1sec 2B + (300 x 2.5ms + 50ms) + 160 x 2.5ms = 3.2 sec A + (300 × 2.5ms + 50ms) + 200 × 2.5ms = 2.3sec A + (300 × 2.5ms + 50ms) + 200 × 2.5ms = 2.3sec 540 × 2.5ms = 1.35sec.

Here, it is assumed that the start of the paper feeding operation is delayed by setting a delay time of 4.5 seconds only when the paper feeding amount is 540 steps or more as in the print end processing shown in FIG.

In this case, the condition that ink stain does not occur is 5.5 after printing.
If the second has elapsed, the above example, line 6, 1.35sec.
Only 5.85 seconds, the condition that ink stain does not occur does not occur and ink stain does not occur, but lines 1 to 5 do not satisfy the condition that ink stain does not occur, so ink stain may occur There is.

On the other hand, in the print end process shown in FIG.
The delay time depends on the paper feed amount even if it is less than step
Set TD.

In this case, the relationship between each LF number (paper feed amount) N and the delay time is as shown in Table 3 (TD = 10N-1000 [mse
c)).

Therefore, if this is applied to the first to sixth rows of the example shown in FIG.
The time to reach 173 is as follows.

That is, for the first to fourth rows, there is no delay time below 100 steps, so the fourth and fifth rows
The delay time (2 seconds corresponding to 300 steps) at each LF after line printing is added twice.

For the 5th line, the delay time (2sec) at the time of LF after printing the 5th line and the delay time at the time of LF (4.5sec) after printing for the 6th line are added. Later LF time delay (4.5 sec) will be added.

Therefore, the time it takes for each print line to reach the discharge roller 173 after printing is 5.0 sec + 2 sec × 2 = 9 sec 4.1 sec + 2 sec × 2 = 8.1 sec 3.2 sec + 2 sec × 2 = 7.2 sec 2.3 sec + 2 sec × 2 = 6.3 sec 2.3sec + 2sec + 4.5sec = 8.8sec 1.35sec + 4.5 = 5.85sec.

In this way, in any print line, the condition that 5.5 seconds have elapsed after printing without causing ink stains does not cause ink stains.

Next, the ACK transmission process when the print operation end response command is received from the host side will be described with reference to FIG.
With this printer with ASF, the paper feed command for the last line operates with a command that does not have feed amount data.
The routine is different from other paper feeding processing.

First, the host sends an operation end response command (code is “ESC + b”) to the printer after printing the last print line, and then commands such as page break, paper feed command, single paper discharge command, compressed LF command, etc. Shall be sent.

In this case, if the printer side immediately returns the ACK signal when it receives the "ESC + b" code from the host side, ink stains may occur if the paper discharge operation is subsequently performed.

Therefore, in this ACK transmission process, the ACK transmission for the operation end response instruction is delayed by a predetermined time when the ASF 2 is installed.

That is, the operation end response command “ECS + b” from the host side
When it receives the ACK, it confirms that the carriage has returned to the home position and prepares to send back an ACK signal to the host side.

Then, after the carriage returns to the home position, it is determined whether or not the ASF2 is installed (ASF / ON).

At this time, if ASF / ON, wait for 4.5 seconds and then
Immediately, if F / ON is not set, a ready is sent to the host side and an ACK signal is sent.

Then, thereafter, the ACK flag (FLAG) and the ESC + b flag are turned off.

That is, when the operation end response command is received after printing the last line, after returning the carriage 43 to the home position,
When ASF2 is installed, ACK is sent back to the host side after 4.5 seconds.

Therefore, even if the operation end response command is followed by a command for page feed, paper feed, paper discharge, etc., to discharge the paper,
Since the time required for the ink on the final print line to dry can be secured, ink stains do not occur.

Note that the determination processing as to whether or not the vehicle is in the home position is performed in the ACK transmission processing in response to the operation end response command based on the following reason.

In other words, in the ink jet printer, the paper guide cannot be provided on the front surface of the carriage as described above, so if the paper discharging operation is performed during the carriage return,
The end portion of the paper may come into contact with the front portion of the carriage 43 to cause ink stains.

Therefore, in the case of printing the last line, by waiting for the end of the carriage return operation and then discharging the paper, the paper end portion does not come into contact with the front surface of the carriage to cause ink stain.

As described above, in this printer, the start of the paper feeding operation after the line printing is completed is controlled based on the paper feeding amount, so that the throughput of the printer is improved.

In the above-described embodiment, since the member that comes into contact with the image on the paper first from the printing position of the printer is the ASF discharge roller, it is determined whether or not the ASF is attached, but the member that comes into contact first is the printer. If it is within the range, it is not necessary to determine whether or not the ASF is attached, and the start of the paper feeding operation may be controlled based on the result of the determination whether or not the image has just been formed and the paper feeding amount.

The present invention is particularly effective when applied to an ink jet printer that requires a long time to dry the ink,
The invention can be applied to not only the ink jet printer but also a thermal printer, a thermal transfer printer, a dot impact printer, a type printer, and the like.

Further, the sheet feeding device is not limited to the ASF, and the same can be applied to a tractor feeder that feeds continuous forms.

As described above, the image forming apparatus according to the present invention is
Since the start of the paper feeding operation after printing is controlled based on the image forming timing and the paper feeding amount, the paper feeding is performed after a predetermined waiting time only when there is a risk of ink stains due to paper ejection. If there is no risk of ink stains, the paper is immediately fed to improve print throughput.

If the start of the paper feeding operation after printing is controlled based on the image forming time, the paper feeding amount, and the presence / absence of the automatic paper feeding device, the automatic paper feeding device has the above-described effects. Even if the printer is not installed and there is no risk of ink stains, the paper is immediately fed, and the printing throughput can be further improved.

Further, the image forming means in the above image forming apparatus,
In the case of the ink jet recording means that requires a certain amount of time from printing to drying, the above-mentioned effect becomes more remarkable.

[Brief description of drawings]

FIG. 1 is a block diagram showing the construction of a paper discharge means in an image forming apparatus according to the present invention, FIG. 2 is an external perspective view showing an example of a printer embodying the present invention, and FIGS. 3 and 4 are the same printers. FIG. 5A is a perspective view showing the mechanical section of this printer, FIGS. 5B and 5C are the same side view and front view of the paper bail roller, and FIG. 6 is the same. Block diagrams showing the construction of the carriage and pump unit, FIGS. 7 to 10 are side views and perspective views of the main parts, which are also used to explain the paper setting mechanism, and FIGS. 11A, 11B and 12 are the same. A sectional view showing a sheet feeding device installed in a printer, a sectional view of its main part and a perspective view of its main part, FIG. 13 is a perspective view showing its drive mechanism part, and FIGS. 14 to 17 are also its clutch mechanism. Perspective view and side view for explanation And a front view, FIG. 18 is a block diagram showing a control unit of the printer, FIGS. 19 to 23 are flow diagrams showing respective processes executed by the main control unit, and FIGS. 24 and 25 are the same. A flow chart showing each processing executed by the interface section, FIG. 26 is a flow chart showing an example of processing at the time of printing on the host side, and FIGS. 27 to 33 are also executed by the interface section and the main control section. FIG. 34, FIG. 35, and FIG. 36. Flow charts showing different examples of print end processing executed by the interface section and explanatory diagrams for explaining the same. Similarly, FIG. 37 is a flow chart showing an example of an ACK transmission process to the host side when the operation end response command is received. 1 …… Printer, 2 …… ASF 14 …… Automatic insertion switch, 26 …… DIP switch 31 …… Platen, 40 …… Paper veil 32 …… Line feed motor 43 …… Carriage, 98 …… Micro switch 111 …… Paper sensor, 114 …… Card guide 131 …… Solenoid 197,197 ′ …… Clutch mechanism 251 …… Interface section 252 …… Main control section

Claims (3)

[Claims] 1. An image forming apparatus comprising: an image forming unit for forming an image on a recording sheet; and an ejecting unit for ejecting the recording sheet on which an image is formed by the image forming unit. If the paper means determines whether or not it is immediately after image formation, and if the determination means determines that it is not immediately after image formation, the paper feeding operation is performed immediately, and if it is determined that it is immediately after image formation. , Comparing the paper feed amount of the recording paper and the distance from the print position to the member that first comes into contact with the image on the recording paper, and if the paper feed amount is not the distance or more, the paper feed operation is immediately performed. If the paper feed amount is equal to or more than the distance,
An image forming apparatus comprising: a paper feed control unit that performs a paper feed operation after a lapse of a predetermined waiting time. 2. An image capable of mounting an automatic paper feeding device, comprising image forming means for forming an image on recording paper, and paper discharging means for discharging the recording paper on which the image is formed by the image forming means. A forming apparatus, wherein the paper discharge means determines a first judgment means for judging whether or not an image has just been formed, and a second judgment means for judge whether or not the automatic paper feeding device is mounted. If it is determined by the first determining means that the image has not been formed immediately afterward, or if the second determining means determines that the automatic paper feeding device is not installed, the paper feeding operation is immediately performed. When it is determined by the first determining means that the image has just been formed, and when the second determining means determines that the automatic sheet feeder is installed, the paper feed amount of the recording sheet and the printing are performed. Paper ejection from the automatic paper feeder from the position Comparing the distance to over La, unless the paper feed amount is the distance or more, immediately performs a paper feeding operation, if the paper feed amount is the distance or more,
An image forming apparatus comprising: a paper feed control unit that performs a paper feed operation after a lapse of a predetermined waiting time. 3. An image forming apparatus according to claim 1 or 2, wherein the image forming means is an ink jet recording means.