JP2002187318A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of setting cut papers accurately at a time. SOLUTION: In setting cut papers on a platen 51, with a solenoid 60 switched on, a sliding cam 62 is moved in the arrow C direction and two positioning members 56, 58 are moved onto projections 62a of the sliding cam 62 so as to be disposed at setting positions. The cut papers are placed so as to butt against the two positioning members 56, 58 disposed at the setting positions. In setting a roll paper on the platen 51, with the solenoid 60 switched off, the sliding cam 62 is moved in the arrow B direction and the two positioning members 56, 58 are moved onto a bottom part 62b of the sliding cam 62 so as to be disposed at withdrawal positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a sheet of cut paper pre-cut to a predetermined size, and more particularly to an image forming apparatus capable of forming an image on roll paper wound in a roll. The present invention relates to a forming apparatus.

[0002]

2. Description of the Related Art As one of output devices of computers and workstations, there is known an image forming apparatus of an ink jet system which forms an image by discharging ink onto a recording medium such as cut paper or roll paper.

A plotter as an example of a conventional ink jet type image forming apparatus will be described with reference to FIGS.

FIG. 4 is a perspective view showing a plotter which forms an image on cut paper. FIG. 5 is a perspective view showing the plotter of FIG. 4 forming an image on roll paper.

[0005] The plotter 10 has a platen 14 on which a cut paper 12 and a roll paper 13 conveyed in the direction of arrow A are placed.
It has. Above the platen 14, two scanning rails (guide rails) are provided in parallel with the platen 14.
16 have been bridged. A carriage 20 reciprocating in the directions of arrows B and C (a direction orthogonal to the direction of arrow A) by a motor (not shown) and a belt (not shown) has a slide bearing (not shown) on the scanning rail 16. Attached through.

The carriage 20 has four print heads 22K (black), 22C (cyan), 22M (magenta), and 22Y (yellow) having ink discharge ports (nozzle outlets, not shown) for discharging ink. ) Is installed. An area in front of the ink ejection port is an image forming area where an image is formed. The ink is discharged from the ink discharge port to a portion of the cut paper 12 or the roll paper 13 which is located in the image forming area, whereby an image is formed on this portion.

At a position on one side of the movable range of the carriage 20 distant from the image forming area, ink is forcibly sucked from the nozzles to clean the ink supply paths and nozzles formed on the print head 22. A recovery device (not shown) for setting the ink discharge state of the print head 22 to an initial discharge state is provided.

In forming an image on a recording medium such as cut paper 12 or roll paper 13, for example, a cut paper 12 is placed on a platen 14, and an opening (not shown) formed in the platen 14 is formed. The transport roller 24 is rotated by a motor (not shown) while nipping the cut paper 12 between the transport roller 24 exposing a part of the outer peripheral surface and a pinch roller 26 pressing both ends of the cut paper 12 from above. The cut paper 12 is transported.

A carriage 20 is reciprocated in the directions of arrows B and C above the cut sheet 12 to control a head controller (not shown).
The ink is ejected from the nozzles based on an image signal carrying image information transmitted to each of the print heads 22K, 22C, 22M, and 22Y to form an image on a portion of the cut sheet 12 located in the image forming area. . During the image forming operation,
When it becomes necessary to suck ink from the nozzles to clean the nozzles and the like, the carriage 2
0 is moved above a recovery device (not shown).

As described above, an image for one band is formed in a portion located in the image forming area. Thereafter, the cut sheet 12 is conveyed by one band and stopped, and the ink is ejected from the nozzles based on the image signal again while the carriage is reciprocated in the directions of arrows B and C again.
The image is formed in a portion newly located in the image forming area among the images. By repeating such an operation, an image is formed on the cut sheet 12.

The procedure for placing the cut paper 12 on the platen 14 will now be described.

First, the pinch roller 26 is moved
The pinch roller release lever 28 is operated in order to separate the pinch roller from the pinch roller. As a result, the pinch roller 26 separates from the transport roller 24 to form a gap between the two. The cut paper 12 is inserted into this gap so that the rear end (the rear end in the direction of arrow A) coincides with the reference line 30.

Next, the pinch roller release lever 28 is returned to the original position, and the cut sheet 12 is moved to the pinch roller 26 and the transport roller 2.
Hold it with 4. Thereafter, the transport roller 24 is rotated,
The trailing end of the cut sheet 12 is detected by a sheet detection sensor 32 arranged on the platen 14. After this detection, the carriage 2
0 is reciprocated in the directions of arrows B and C, and the width (length in the directions of arrows B and C) of the cut sheet 12 is detected using the sheet detection sensor 34 mounted on the carriage 20.

Thereafter, the cut sheet 12 is conveyed in a direction opposite to the direction of arrow A while the carriage 20 is stopped above the cut sheet 12. During this conveyance, the paper detection sensor 3
4 detects the leading end (the leading end in the direction of arrow A) of the cut sheet 12 and stops the cut sheet 12 in accordance with the above-described image forming area.

According to the above procedure, the leading edge of the cut sheet 12 is adjusted to the print start position, and the plotter 1
“0” stores a printable area corresponding to the vertical size and the width size of the cut sheet 12. In this state, a print waiting state (print standby state) is established.

By the way, as shown in FIG.
At 0, an image may be formed on the roll paper 13 in some cases. In this case, the roll paper 13 is set while pulling the leading end (downstream end in the direction of arrow A) of the roll paper 13 in the direction of arrow A.
Thereafter, the width (length in the directions of arrows B and C) of the roll paper 13 is detected using the paper detection sensor 34, and the leading end of the roll paper 13 (the leading end in the direction of arrow A) is aligned with the above-described image forming area. The paper 13 is stopped.

[0017]

As described above, when the cut sheet 12 is set on the platen 14, the cut sheet 1
The rear end of 2 (the rear end in the direction of arrow A) is matched with the reference line 30. In this case, since the user sets the sheet visually, the rear end of the cut sheet 12 slightly deviates from the reference line 30 (the reference line 30).
Does not exactly match). Due to such “shift”, there is a possibility that the cut sheet 12 skews and deviates from the printable area. Further, in order to correct the skew, it is necessary to set the cut sheet 12 again, and the image forming apparatus may not be easy to use.

The present invention has been made in view of the above circumstances, and has as its object to provide an image forming apparatus capable of accurately setting cut sheets at one time.

[0019]

In order to achieve the above object, an image forming apparatus according to the present invention includes a platen on which a recording medium is placed while spreading in a predetermined main scanning direction, and is mounted on the platen. In an image forming apparatus for forming an image on a cut sheet, (1) selectively at either an initial set position when the cut sheet is placed on the platen or a retract position where the cut sheet is retracted away from the set position. And (2) switching means for switching the positioning member to be located at either the set position or the retracted position.

Here, the image forming apparatus may include (3) a plurality of sheet detection sensors arranged in a direction perpendicular to the sheet conveying direction in which the cut sheet is conveyed, for detecting the cut sheet.

Further, the image forming apparatus may include (4) a plurality of sheet detection sensors arranged in the sheet conveying direction in which the cut sheet is conveyed, for detecting the cut sheet.

Further, the switching means includes: (5) a positioning member which is located at one of the set position or the retracted position based on which of the plurality of paper detection sensors has detected paper. May be located.

Further, (6) the image forming apparatus includes suction means for attracting a recording medium to the platen, and (7) the switching means detects any one of the plurality of paper detection sensors. The suction unit may be driven based on whether the sensor detects a sheet.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a plotter which is an embodiment of the image forming apparatus of the present invention. FIG. 2 is a schematic diagram showing a vertical movement mechanism for vertically moving a positioning member.
FIG. 3 is a block diagram showing a control system for controlling the solenoid of FIG. In these drawings, the same components as those shown in FIG. 4 are denoted by the same reference numerals.

The characteristics of the plotter 50 are that two paper detection sensors 52 and 54 for detecting a recording medium such as the cut paper 12 and the roll paper 13 (see FIG. 5) are provided.
The point is that two positioning members 56 and 58 are provided. The two paper detection sensors 52 and 54 are arranged in the paper transport direction (the direction of arrow A). Also, two paper detection sensors 5
The paper detection sensor 52 is disposed downstream of the transport roller 26 in the paper transport direction. On the other hand, the paper detection sensor 54 is disposed upstream of the transport roller 26 in the paper transport direction. The positions of the two sheet detection sensors 52 and 54 are positions where the recording medium of the minimum size used for the plotter 50 is covered by the recording medium when the recording medium is placed on the platen 51.

The two positioning members 56 and 58 described above
Is located at an initial setting position when the cut sheet 12 is set on the platen 51. This position is the same as the position of the reference line 30 shown in FIG. Two positioning members 5
The coils 6, 58 are urged downward (in the direction of arrow D) by coil springs 56a, 58a, respectively.

Below the platen 51, a solenoid 60 for moving the two positioning members 56 and 58 up and down, a slide cam 62, a slide base 64 and the like are arranged. A slide cam 62 is provided on the slide base 64.
Are formed in the directions of arrows B and C.

The plotter 50 has a solenoid 60.
A control unit 70 for turning on and off the power supply is built in. The control unit 70 turns on and off the solenoid 60 based on sheet detection signals from the two sheet detection sensors 52 and 54. With this on / off, the slide cam 62 moves to the arrow B,
By moving in the direction C, the two positioning members 56 and 58 move up and down. When the solenoid 60 is turned on and the slide cam 62
Moves in the direction of arrow C, and the two positioning members 56 and 58 move.
Gets on the projection 62a of the slide cam 62,
The upper ends of the positioning members 56 and 58 protrude from the surface (upper surface) of the platen 51. At this time, the positioning member 56,
The position of 58 is the cut sheet 1 set on the platen 51.
2 is the set position where it abuts.

On the other hand, when the solenoid 60 is turned off and the slide cam 62 moves in the direction of arrow B and the two positioning members 56, 58 ride on the bottom 62b of the slide cam 62, the upper ends of the positioning members 56, 58 51 is located below the surface (upper surface). The positions of the positioning members 56 and 58 at this time are retreat positions where the cut paper 12 and the roll paper 13 are smoothly conveyed without being disturbed. The switching means according to the present invention is constituted by the solenoid 60, the slide cam 62, the slide base 64, and the like.

In addition, under the platen 51, a suction fan (an example of a suction means according to the present invention, which is a suction means for adsorbing the cut paper 12 and the roll paper 13 to the platen 51,
(Not shown). The suction fan is configured to stop for a predetermined time when the paper detection sensors 52 and 54 detect the cut paper 12 or the roll paper 13. Therefore, the cut paper 12 and the roll paper 13 can be easily set.

Here, the procedure for placing the cut paper 12 on the platen 51 will be described.

First, the pinch roller 26 is moved to the transport roller 24.
The pinch roller release lever 28 is operated in order to separate the pinch roller from the pinch roller. As a result, the pinch roller 26 separates from the transport roller 24 to form a gap between the two. The cut paper 12 is inserted into this gap. In this case, since the cut sheet 12 is inserted in the direction opposite to the direction of arrow A, the sheet detection sensor 52 of the two sheet detection sensors 52 and 54 detects the cut sheet 12 earlier than the sheet detection sensor 54. I do.

A detection signal indicating that the sheet detection sensor 52 has detected the cut sheet 12 is transmitted to the control unit 70,
The solenoid 60 is turned on. Accordingly, as described above, the slide cam 62 moves in the direction of arrow C, and the two positioning members 56 and 58
The rider gets on a and is located at the set position. Cut paper 12 is attached to two positioning members 56 and 58 located at the set position.
And pinch roller release lever 2 in this state.
8 is returned to the original position, and the cut sheet 12 is
And the conveying roller 24.

The pinch roller release lever 28 that has returned to the original position is detected by the lever position detection sensor 72, and this detection signal is transmitted to the control unit 70. As a result, the solenoid 60 is turned off, and as described above, the slide cam 62 is turned off.
Moves in the direction of arrow B, and the two positioning members 56 and 58 move.
Is positioned at the retracted position on the bottom 62b of the slide cam 62.

Next, the transport roller 24 is rotated to transport the cut sheet 12 in the direction of arrow A, and the sheet detection sensor 54 detects the rear end (upstream end in the direction of arrow A) of the cut sheet 12.
After this detection, the carriage 20 is reciprocated in the directions of arrows B and C, and the width of the cut sheet 12 (arrows B and C) is detected using the paper detection sensor 34 (see FIG. 4) mounted on the carriage 20.
C direction length).

Thereafter, the cut sheet 12 is conveyed in a direction opposite to the direction of arrow A while the carriage 20 is stopped above the cut sheet 12. During this conveyance, the paper detection sensor 5
2 detects the leading end (downstream end in the direction of arrow A) of the cut sheet 12 and stops the cut sheet 12 in accordance with the above-described image forming area.

According to the above procedure, the leading edge of the cut sheet 12 is adjusted to the print start position, and the plotter 5
“0” stores a printable area corresponding to the vertical size and the width size of the cut sheet 12. In this state, a print waiting state (print standby state) is established.

By the way, as shown in FIG.
Similarly, the plotter 50 may form an image on the roll paper 13 (see FIG. 5). In this case, the roll paper 13 is set while pulling the leading end (downstream end in the direction of arrow A) of the roll paper 13 in the direction of arrow A. For this reason, the paper detection sensor 54 of the two paper detection sensors 52 and 54 detects the roll paper 13 earlier than the paper detection sensor 52. At this time, the control unit 70 determines that the cut sheet 12 is not the cut sheet 12 but the roll sheet 13 and the solenoid 60 is not turned on. Therefore, since the positioning members 56 and 58 remain at the retracted position, the roll paper 13 is smoothly conveyed without being disturbed. Thereafter, the roll paper 13 is in a print waiting state in the same manner as the cut paper 12. Note that the two sheet detection sensors 52 and 54 may be arranged in a direction (arrow B and C directions) orthogonal to the sheet transport direction (arrow A direction). In this case, it can be determined whether the recording medium is inserted from the upstream side in the arrow A direction or the recording medium is inserted from the downstream side in the arrow A direction.

[0040]

As described above, according to the image forming apparatus of the present invention, the positioning member is positioned at the set position, and the cut sheet is placed against the positioning member so that the cut sheet fails. It can be set exactly once without having to do it. As a result, there is no need to repeatedly touch the cut sheet, so that the cut sheet is not stained.

Here, when the image forming apparatus includes a plurality of sheet detection sensors arranged in a direction perpendicular to the sheet conveying direction in which the cut sheet is conveyed to detect the cut sheet, By detecting the width (the length in the direction perpendicular to the paper transport direction), the range (area) in which an image is to be formed becomes clear.

When the image forming apparatus has a plurality of paper detection sensors arranged in the paper transport direction in which the cut paper is transported, and detects the cut paper, the length of the cut paper (the paper transport Direction) is detected,
The range (area) where an image is to be formed becomes clear.

Further, the switching means positions the positioning member at either the set position or the retracted position based on which of the plurality of paper detection sensors has detected the paper. For example, when the roll paper is set from the roll paper setting direction opposite to the cut paper setting direction in which the cut paper is set and an image is formed on the roll paper, the paper is more transported than the positioning member. A paper detection sensor is arranged upstream (in the roll paper setting direction), and when this paper detection sensor detects paper earlier (earlier) than other paper detection sensors, the positioning member is moved to the retracted position. Position. Thereby, the positioning member does not become an obstacle, so that the roll paper can be set smoothly.

[0044] Further, there is provided suction means for adsorbing a recording medium on the platen, and the switching means detects the suction based on which paper detection sensor of the plurality of paper detection sensors has detected paper. In the case of driving the means, for example, a paper detection sensor is arranged downstream of the positioning member in the cut paper setting direction (the direction in which the cut paper is set), and this paper detection sensor Since the suction means is not driven when the first detection is made, the suction means is not driven when setting the cut paper, so that the cut paper can be easily set, and a user-friendly image forming apparatus can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a plotter that is an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a schematic diagram showing a vertical movement mechanism for vertically moving a positioning member.

FIG. 3 is a block diagram showing a control system for controlling the solenoid of FIG. 2;

FIG. 4 is a perspective view showing a conventional plotter that forms an image on cut paper.

FIG. 5 is a perspective view showing the plotter of FIG. 4 forming an image on roll paper.

[Explanation of symbols]

 12 Cut paper 50 Plotter 51 Platen 52, 54 Paper detection sensor 56, 58 Positioning member 60 Solenoid 62 Slide cam 64 Slide base 66 Guide plate 70 Control unit

Claims (5)

[Claims] 1. An image forming apparatus comprising: a platen on which a recording medium is placed while spreading in a predetermined main scanning direction, and forming an image on cut paper placed on the platen; A positioning member selectively located at either of an initial set position at the time of placing, and a retreat position retreating away from the set position, and the positioning member being located at either the set position or the retreat position. An image forming apparatus comprising: a switching unit for performing a switching operation. 2. The image forming apparatus according to claim 1, further comprising a plurality of sheet detection sensors arranged in a direction orthogonal to a sheet conveying direction in which the cut sheet is conveyed, and configured to detect the cut sheet. . 3. The image forming apparatus according to claim 1, further comprising a plurality of sheet detection sensors arranged in a sheet conveying direction in which the cut sheets are conveyed, and configured to detect the cut sheets. 4. The switching means positions a positioning member at one of the set position and the retreat position based on which of the plurality of paper detection sensors detects a paper. The image forming apparatus according to claim 2, wherein the image forming apparatus is an image forming apparatus. 5. A suction device for adsorbing a recording medium on the platen, wherein the switching device detects the suction device based on which of the plurality of paper detection sensors detects a sheet. 5. The image forming apparatus according to claim 2, wherein the image forming apparatus drives the image forming apparatus.