JPH05104709A - Ink jet printer - Google Patents

Abstract

PURPOSE:To improve processing efficiency as a whole by providing a paper discharge means equipped with 1st and 2nd paper discharge routes of two recording media respectively having ink permeability different from each other, a switching means for the paper discharge routes, and a heating and stand-by means in the 2nd paper discharge route. CONSTITUTION:A sheet detector 23 detects type of a printing sheet 3 passing by. When the printing sheet 3 to be sent is a paper sheet, a diverter 25 is switched to a solid line position and printing is performed with an ink jet head 13 by sending the paper sheet upward with a sheet holding roller 39. After the printing is completed, the sheet is discharged on a paper discharge tray 53 along a paper discharge guide 17. When it is an OHP sheet, the diverter 25 is switched to a broken line position and printing is performed in the same manner as the case of the paper sheet. When printing data continues, it stands by at an OHP stand-by unit B and stands by in sequence as far as the printing sheet 3 is the OHP sheet. When there is no printing data, the sheet is sent into a heating device 33 by a paper feed roller 27. After ink flattening process is performed, the sheet is discharged on the paper discharge tray 53 along a paper discharge guide 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium having ink permeability (for example, a paper sheet) and a recording medium having no ink permeability (for example, a polymer sheet) by ejecting hot melt type ink from an ink jet head. The present invention relates to an inkjet printer that prints on both recording media, and in particular, a recording device that has a heating device that heats a recording medium that does not have ink permeability, and that does not have ink permeability even if the heating process by such a heating device takes time. The present invention relates to an inkjet printer that can quickly perform a series of processes from printing of a medium to discharging.

[0002]

2. Description of the Related Art Conventionally, characters such as characters are printed by ejecting a so-called hot-melt type ink having a property of keeping a solid state at room temperature and melting when heated to a temperature higher than a melting point onto a recording medium through an inkjet head. Inkjet printers have been proposed. According to such inkjet printers, not only ordinary paper sheets but also transparent polymer sheets (hereinafter referred to as OHP) for projecting characters printed by an overhead projector or the like are projected.
It is possible to print on a sheet).

In such an ink jet printer, the amount of ink ejected from the ink jet head is extremely small, and the heat capacity thereof is also small. Therefore, when the ink adheres to the recording medium as described above, the heat is immediately removed and the ink solidifies. At this time, in the case of a paper sheet, the attached ink does not rise so much on the paper sheet because it has ink permeability between the fibers of the paper, but in the case of an OHP sheet, it does not have the ink permeability like the paper sheet. The attached ink rises on the OHP sheet.

The ink raised on the OHP sheet becomes a convex lens shape, and in the case of an OHP sheet on which color characters and the like are printed by hot melt type ink containing a semi-transparent component, the light irradiated on the OHP sheet by the effect of the convex lens is Since it is refracted or dispersed in a complicated manner, a clear image such as a color character cannot be obtained. In order to prevent this, as described in US Pat. No. 4,853,706, etc., the ink which has been solidified on the OHP sheet after being printed and then solidified on the OHP sheet is heated again to a temperature equal to or higher than the melting point so that the ink raised in the shape of a convex lens is removed. A method of melting and flattening has been proposed.

In this type of ink jet printer capable of printing on both a paper sheet and an OHP sheet, a heating device is required for flattening the ink ejected and raised on the OHP sheet, and such a heating device is also required. It is built into the inkjet printer body to continuously perform a series of processes from printing to discharging.

Conventionally, in an ink jet printer incorporating the above-mentioned heating device, it is necessary to selectively heat the OHP sheet, so that the paper ejection path after printing is a paper sheet ejection path and an OHP sheet ejection path. Although it is divided into a paper path, the paper discharge device is configured to share a paper sheet and an OHP sheet, and the paper sheet and the OHP sheet are mixed in the recording medium to be printed. If there is OH
The next sheet is printed and discharged after waiting for the end of the heating process and the discharge of the P sheet.

[0007]

However, the heating process of the OHP sheet by the heating device is performed after printing and it takes a relatively long time, so that it is necessary to perform a series of processes from printing to discharging. The time required will be longer than for paper sheets that do not require heat treatment.

Therefore, when printing an image such as characters,
In the conventional ink jet printer, the paper discharge device is commonly used for both the paper sheet and the OHP sheet. Therefore, if there is an OHP sheet in the recording medium, the heating device heats the OHP sheet and discharges the paper as described above. Waiting until the paper discharge process by the device is completed, the printing process and the paper discharge process of the next sheet will be performed. Therefore, since the heating process of the OHP sheet takes time, the overall process of the inkjet printer is performed. There was a problem that the efficiency decreased. Such a problem is compounded as the number of OHP sheets to be heat-treated and discharged is increased.

The present invention has been made to solve the above-mentioned problems of the prior art, and is provided upstream of the heating means provided in the middle of the paper discharge path of the recording medium having no ink permeability in the paper discharge means. By providing a standby means for holding the recording medium in a standby state, a series of processes from printing to discharging of the recording medium having ink permeability can be performed quickly, and thus the overall processing efficiency of the inkjet printer is improved. It is an object of the present invention to provide an inkjet printer capable of performing the above.

[0010]

In order to achieve the above-mentioned object, the present invention has a recording medium conveying means for conveying two recording mediums of different types with respect to the presence or absence of ink permeability, and the recording medium conveying means. Discriminating means for discriminating the type of recording medium, printing means for ejecting hot melt type ink onto the recording medium to print characters and the like, and one of the recording media printed by the printing means having ink permeability Of the recording medium, and a second discharge path for discharging the other recording medium having no ink permeability, and a determination result of the determination means. Based on the switching means, the sheet discharge path of the sheet discharge means is switched between the first sheet discharge path and the second sheet discharge path, and the other recording medium provided in the middle of the second sheet discharge path is heated. Heating means for Wherein the a waiting means to keep on standby the other recording medium upstream of the heating means and structure provided with the discharge path.

[0011]

In the present invention having the above structure, first, the discriminating means discriminates the type of the recording medium conveyed from the recording medium conveying means. When the recording medium is a recording medium having no ink permeability, the sheet discharging path of the sheet discharging means is switched to the second sheet discharging path through the switching means based on the determination result of the determining means, and then the recording means is performed by the printing means. Characters and the like are printed on top. After such printing, the recording medium is put on standby by the standby unit, but as long as the recording medium is a recording medium having no ink permeability, the recording unit is sequentially placed on standby by the standby unit.

When the discriminating means discriminates that the recording medium to be printed next is a recording medium having ink permeability, the ejecting path of the ejecting means is first ejected via the switching means based on the discrimination result. The recording medium, which has been switched to the paper path and on which characters and the like have been printed by the printing means, is discharged from the first paper discharge path. Such a series of processing is continuously performed as long as the recording medium having ink permeability is continued.

Subsequently, as described above, the recording medium having no ink permeability which is on standby in the standby means is fed through the second paper discharge path and sequentially heated by the heating means, and then the second The paper is discharged through the paper discharge path.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a side sectional view of an ink jet printer. In FIG. 1, a paper feed cassette 5 holding print sheets 3 as recording media in a stack is detachably attached below the ink jet printer 1 (see FIG. 1).
Indicates a state in which the paper feed cassette 5 is mounted). The print sheet 3 includes a paper sheet made of plain paper having ink permeability and an OHP sheet made of a polyester film sheet having no ink permeability. All of these sheets are held in the paper feed cassette 5 in a stacked state.

A paper feed roller 7 is arranged above the mounting position of the paper feed cassette 5. This paper feed roller 7
Contacts the print sheet 3 at the uppermost position of the paper feed cassette 5 mounted on the printer 1 and is rotationally driven by a known paper feed motor to separate the print sheets 3 from the paper feed cassette 5 one by one. It is supplied to the paper feed guide 9.

A pair of paper feed guides 9 are provided on the right side of the paper feed roller 7 in the figure. The paper feed guides 9 are print sheets supplied from the paper feed cassette 5 by the paper feed rollers 7. 3 is conveyed and guided to a printing unit 11 (described later) provided downstream of the paper feed guide 9.

A sheet detector 23 is arranged at the downstream end of the paper feed guide 9, and the sheet detector 2 is provided.
3 is a type of the print sheet 3 which is formed by disposing the light emitting diode 23a and the photodiode 23b apart from each other, that is, a paper sheet having ink permeability or an ink permeability. Not OHP
The sheet is detected.

When the print sheet 3 fed between the diodes 23a and 23b is a paper sheet, the sheet detector 2
Since 3 detects the light blocking state of the light emitted from the light emitting diode 23a, it is determined that the paper sheet has been fed by the detection of this light blocking state. Further, when the OHP sheet is fed, the sheet detector 23 detects the transmission state of the light emitted from the light emitting diode 23a, and thus it is determined that the OHP sheet has been fed by the detection of the transmission state.

In the printing section 11 arranged downstream of the sheet detector 23, an ink jet head 13 and an ink jet head 13 for ejecting hot melt type ink onto the print sheet 3 to print characters and figures. The platen 15 that supports the print sheet 3 at the opposite position, and the sheet holding rollers 37 and 39 that have a pair of rollers at the upstream and downstream positions of the inkjet head 13 are provided.

Here, the ink jet head 13 contains therein a plurality of hot-melt inks of a main color which are melted, and when it is driven by a driving device, the printing data inputted from an external device such as a personal computer is converted. Accordingly, ink droplets of a required color are ejected onto the print sheet 3 supported on the platen 15 to print images such as characters and figures on the print sheet 3. Since the configuration and control procedure of the drive unit for the printing unit 11 have been publicly known, detailed description thereof will be omitted here.

Further, the platen 15 supports the print sheet 3 during printing by the ink jet head 13, and a heater is built into the platen 15 so that when printing on a paper sheet, the platen 15 is moved into the paper sheet of ink. Is designed to promote the penetration of Further, the holding roller 37,
Reference numeral 39 is for holding and positioning the print sheet 3 during printing by the inkjet head 13.

Next, at the downstream side of the holding roller 39 of the printing section 11, a paper sheet discharging section A including a discharging guide plate 17 is provided.
And an OHP sheet standby portion B composed of standby guide plates 31A and 31B are arranged in a branched manner. Paper ejection guide plate 1
At the downstream end of 7, the paper discharge roller 19 and the paper discharge roller 1
9 is provided with a pinch roller 21 pressed against the sheet 9 with a predetermined pressure. The paper discharge roller 19 and the pinch roller 21 cooperate with each other to sandwich the paper sheet guided by the paper discharge guide plate 17 therebetween. The paper is discharged to the outside of the inkjet printer 1.

A feed roller 27 and a friction roller 29 which is pressed against the feed roller 27 with a predetermined pressure are provided at the downstream end of the standby guide plate 31A (lower part of the back surface of the printing unit 11). , Standby guide plates 31A, 31B,
The feed roller 27 and the friction roller 29 cooperate with each other to
It constitutes an HP sheet standby unit. In the standby portion B, the front end of the OHP sheet fed along the standby guide plates 31A and 31B is brought into contact with the friction roller 29 and guided on the standby guide plate 31A to be on standby.

Here, the feeding roller 27 and the friction roller 29
The standby guide plate 31B is located upstream of the standby guide plate 31B.
It is formed shorter than A, and the standby guide plate 3
On the right side of FIG. 1A in the drawing, a sufficient space is provided so that a plurality of OHP sheets can be accumulated and made to stand by.

Further, the feeding roller 27 has a sufficiently high friction coefficient with respect to the OHP sheet, and the friction roller 29
Has a lower friction coefficient than the feeding roller 27, but has a higher friction coefficient with respect to the OHP sheet. As a result, the feeding roller 27 and the friction roller 29 have a so-called friction separation function, and the OH which is on standby by the standby guide plate 31A.
The P sheets are separated one by one by both rollers 27 and 29 and sent from a guide plate 41 to a heating device 33 described later.

Standby guide plate 31 of OHP sheet standby section B
A heating device 33 is disposed downstream of the guide plate 41 continuous with A, and the heating device 33 is provided with two pairs of guide auxiliary rollers 43 and 45 and a heating platen 35. The guide auxiliary rollers 43 and 45 cooperate with each other to form the OH.
The OHP sheet fed from the P sheet waiting section B is guided in the heating device 33, and the heating platen 35 is held at a temperature slightly higher than the melting point of the hot melt type ink and is discharged onto the OHP sheet. The solidified ink is heated again to be melted and the raised ink is flattened.

Further, a guide plate 47, a guide auxiliary roller 49, and a discharge guide plate 51 are disposed downstream of the heating device 33, and the OHP sheet heat-treated by the heating device 33 is provided via these. The paper is fed between the paper discharge roller 19 and the pinch roller 21.

A paper discharge tray 53 is disposed below the paper discharge roller 19, and the paper discharge roller 19 and the pinch roller 21 are provided.
The paper sheet and the OHP sheet discharged by the above are stacked on the discharge tray 53.

The discharge guide plate 17 and the standby guide plate 31
A diverter 25 is rotatably arranged around a shaft 26 at a branch point of A and 31B, and the diverter 25 is part of a guide path to the paper sheet discharge section A and the OHP sheet standby section B. On the basis of the detection result by the sheet detector 23, the solid line position (paper sheet discharging position) and the broken line position (OHP sheet feeding position) in FIG. 1 are switched via a solenoid (not shown).

As a result, when the print sheet 3 fed from the paper feed cassette 5 is detected by the sheet detector 23 as a paper sheet, the diverter 25 is rotated around the shaft 26 and is rotated as shown in FIG. The paper sheet switched to the solid line position and printed by the inkjet head 13 is guided from the sheet holding roller 39 to the paper ejection guide plate 17, and is ejected by the paper ejection roller 19 and the pinch roller 21.
7 is ejected.

When the print sheet 3 fed from the sheet feeding cassette 5 is detected by the sheet detector 23 to be an OHP sheet, the diverter 25 is rotated around the shaft 26 and is broken line in FIG. The OHP sheet switched to the position and printed by the inkjet head 13 is guided from the sheet holding roller 39 between the standby guide plates 31A and 31B and accumulated on the standby portion B in cooperation with the feeding roller 27 and the friction roller 29. Waited in.

Next, the control system of the ink jet printer 1 configured as described above will be described with reference to FIG. FIG. 2 shows a block diagram of the inkjet printer 1. The inkjet printer 1 has a CPU 6
Control is performed with 1 as the core.

In FIG. 2, the CPU 61 has a RAM 63.
The RAM 63 temporarily stores various data calculated by the CPU 61. For example, a print buffer for storing print data to be printed on the print sheet 3 by the print head 13 or the like. have.

A ROM 65 is connected to the CPU 61, and a program required for various controls of the ink jet printer 1, for example, a print control program for performing print control of the ink jet head 13, is stored in the ROM 65.
Rotation control of the paper feed roller 7, rotation control of the diverter 25,
Programs necessary for heating control of the heating platen 35 and the like are stored, and the CPU 61 executes various controls based on these control programs.

The CPU 61 is connected to the paper feed roller 7 via a paper feed control circuit 67, and the CPU 61 drives the paper feed motor to rotate via the paper feed control circuit 67 to control the rotation of the paper feed roller 7. I do.

Further, the ink jet head 13 is connected to the CPU 61 via the print head drive circuit 69, and the CPU 61 controls the ink jet head 13 via the print head drive circuit 69 based on the print control program stored in the ROM 65. The hot melt type ink is driven from the inkjet head 13 in accordance with the print data stored in the print buffer of the RAM 63 and printed on the print sheet 3.
It is ejected on top to print characters.

Further, the diverter 25 is connected to the CPU 61 via the sheet detector 23 and the diverter control circuit 71, and the CPU 61 drives the solenoid by the diverter control circuit 71 based on the detection signal from the sheet detector 23. Rotation control is performed.

The CPU 61 has a friction separation control circuit 73.
The rotation of the feeding roller 27 is controlled via the feeding roller 27 and the OHP sheets waiting in the OHP sheet waiting portion B are sequentially fed one by one from the guide plate 41 to the heating device 33, and the heating platen 35 is also fed via the heating processing control circuit 75. Is controlled so that the temperature of the ink is always maintained at a temperature equal to or higher than the melting point of the hot-melt ink.

The thermistor 7 connected to the CPU 61
Reference numeral 7 is for detecting the temperature of the heater built in the platen 15, and the CPU 61 is the thermistor 77.
The temperature of the heater in the platen 15 is controlled on the basis of the detection result.

Next, the operation of the ink jet printer 1 configured as described above will be described with reference to FIG. FIG. 3 is a flow chart of the paper feed control program for the print sheet 3. In step 1 (hereinafter abbreviated as S), first, when the print start switch is pressed, the paper feed roller 7 starts its rotation, The uppermost print sheet 3 stacked on the paper cassette 5 is sent toward the printing unit 11 via the paper feed guide 9.

Next, in S2, when the print sheet 3 thus sent passes between the light emitting diode 23a and the photodiode 23b of the sheet detector 23, the type of the sheet is detected. When the sent print sheet 3 is a paper sheet, the light shielding state of the light emitted from the light emitting diode 23a is detected, and therefore the process proceeds to S3, and the diverter 25 causes the diverter control circuit 7 to perform the detection based on the detection result.
It is rotated about the shaft 26 via 1 and is switched to the solid line position in FIG. After that, the paper sheet is conveyed upward while being nipped by the sheet holding roller 37 and is nipped by the other sheet holding roller 39 and supported by the platen 15.

Next, in S4, the print head drive circuit 6
The ink jet head 13 is driven via 9 to feed the paper sheet upward by the sheet holding rollers 39 and 41, and hot-melt type ink droplets of a predetermined color are ejected onto the paper sheet to perform desired printing of characters and the like. Be seen. At this time, the heater built in the platen 15 is maintained at a constant temperature via the thermistor 77, and the hot melt type ink ejected onto the paper sheet thereby promotes the penetration between the paper fibers of the paper sheet. To be done.

After the printing is completed, in S5, the paper sheet is fed along the paper ejection guide plate 17 while being guided by a part of the diverter 25 by the sheet holding roller 39, and then the paper ejection roller 19 and the pinch roller 21 are connected. The paper is discharged to the paper discharge tray 53 in cooperation.

On the other hand, when the print sheet 3 fed from the sheet feeding cassette 5 through the sheet feeding roller 7 is an OHP sheet, the state of transmission of the light emitted from the light emitting diode 23a by the sheet detector 23 in S2. Is detected, so S
6, the diverter 25 uses the diverter control circuit 71 based on the detection result to transmit the shaft 26 through the solenoid.
It is rotated about and is switched to the position indicated by the broken line in FIG.

Thereafter, in S7, as in the case of the paper sheet, the OHP sheet is held upward by the sheet holding rollers 37 and 39 and is also supported by the platen 15, and is placed on the OHP sheet via the ink jet head 13. Hot-melt type ink droplets are ejected to perform desired printing of characters and the like.

Next, in S8, the print data following this is R
It is determined whether or not it is in the AM 63, and if there is print data, the process proceeds to S9 and the OHP sheet is waited in the OHP sheet waiting section B. After that, the process returns to S2, and the type of the print sheet 3 is detected again by the sheet detector 23. As a result of the detection, when the next print sheet 3 is an OHP sheet, the above S6, S7, and S8 are executed, and as long as the print sheet 3 is an OHP sheet, the OHP sheets are sequentially waited in the OHP sheet waiting section B. Go

The next print data is sent to the RAM 63 in S8.
If it does not exist, the process proceeds to S10, and the printed OHP
The sheet is fed by the feed roller 27 via the friction separation control circuit 73.
Is driven to be fed into the heating device 33 from the guide plate 41. In subsequent S11, the OHP sheet is sent in the direction of the heating platen 35 by the guide auxiliary rollers 43 and 45, and is discharged onto the OHP sheet by the heating platen 35 whose heating is controlled via the heating processing control circuit 75 and solidified in a raised state. The hot-melt ink that is being melted is remelted and the ink is flattened.

After the flattening of the ink by the heating platen 35, the OHP sheet is sent to be discharged by the guide plate 47, the guide assist roller 49 and the discharge guide plate 51 in S5, and the discharge roller 19 is discharged. The paper is ejected to the paper ejection tray 53 in cooperation with the pinch rollers 21.

As described above in detail, in the ink jet printer 1 according to the present embodiment, the sheet detector 23 detects the type of the print sheet 3, and the diverter 25 is selectively rotated based on the detection result to selectively rotate the paper sheet. Select the paper discharge path according to each of the
Since the OHP sheet standby portion B including the standby guide plates 31A and 31B, the feeding roller 27, and the friction roller 29 is formed upstream of the heating device 33 provided in the discharge path of the OHP sheet, the paper is printed in the print sheet 3. Even when sheets and OHP sheets are mixed, it is possible to preferentially perform the print processing and the paper discharge processing of the paper sheet before performing the flattening processing of the ink on the OHP sheet by the heating platen 35 which takes a relatively long time. ..

Therefore, it is not necessary to perform the print processing and the paper discharge processing of the paper sheet after waiting the end of the heating processing and the paper discharge processing of the OHP sheet as in the conventional ink jet printer. Can be totally improved without decreasing.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications and improvements can be made without departing from the spirit of the present invention.

[0052]

As described above, according to the present invention, the standby means for keeping the recording medium on standby upstream of the heating means provided in the discharge path of the recording medium having no ink permeability in the discharge means. By providing the ink jet printer, it is possible to rapidly perform a series of processes from printing of a recording medium having ink permeability to paper ejection, and thus to provide an ink jet printer capable of improving the processing efficiency of the ink jet printer in total. Can be achieved, and its industrial effect is great.

[Brief description of drawings]

FIG. 1 is a side sectional view of an inkjet printer.

FIG. 2 is a block diagram of an inkjet printer.

FIG. 3 is a flowchart of a print sheet feeding control program.

[Explanation of symbols]

 1 Inkjet Printer 3 Printing Sheet 7 Paper Feeding Roller 9 Paper Feeding Guide 11 Printing Section 13 Inkjet Head 17 Paper Ejection Guide Plate 23 Sheet Detector 25 Diverter 27 Feeding Roller 29 Friction Roller 31A, 31B Standby Guideplate 33 Heating Device 35 Heating Platen 41, 47 Guide plate 51 Paper ejection guide plate

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 13/00 9210-2C

Claims (1)

[Claims] 1. A recording medium conveying unit that conveys two recording mediums of different types with respect to the presence or absence of ink permeability, a discriminating unit that discriminates the type of the recording medium conveyed by the recording medium conveying unit, and the recording medium. Printing means for ejecting hot-melt type ink on the top to print characters and the like; a first paper discharge path for discharging one recording medium having ink permeability among the recording media printed by the printing means; Based on the discrimination result of the discriminating means, the paper ejecting means provided with a second paper ejecting path for ejecting the other recording medium having no ink permeability, Switching means for switching between the first sheet discharge path and the second sheet discharge path; heating means provided in the middle of the second sheet discharge path for heating the other recording medium; and heating for the second sheet discharge path. Others above the means An ink jet printer, characterized in that a standby means for holding one of the recording media in standby is provided.