JPH05104708A - Ink jet printer - Google Patents

Abstract

PURPOSE:To provide an ink jet printer wherein processing time can be shortened without stopping a series of processes from printing to paper discharge whichever recording medium of different types relating to the presence of ink permeability is used, so as to improve processing efficiency as a whole. CONSTITUTION:When a printing sheet 3 is an OHP sheet, after characters are printed by an ink jet head 13, a heating device 27 flattens raised ink by switching a diverter 25. Thereafter, the OHP sheet is discharged on a paper discharge tray 37 by a paper discharge roller 33. When printing process and paper discharge process of the paper sheet are to be performed midway of the flattening process of the raised ink on the OHP sheet, the diverter 25 is switched again, so that the paper sheet is printed and discharged on the paper discharge tray 37 in parallel. with the flattening process of the ink on the OHP sheet and discharging process thereof by a paper discharge roller 19 through a paper discharge guide plate 17.

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 more particularly to an inkjet printer that can improve the efficiency of a series of processes from printing to discharging as an inkjet printer when printing on any recording medium. Is.

[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.

[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, wait until the heating process of the OHP sheet by the heating device is completed. Since the print processing and the paper discharge processing of the next sheet are performed, and thus the heating processing of the OHP sheet takes time, there is a problem that the overall processing efficiency of the inkjet printer is reduced. .. 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 in order to solve the above-mentioned problems of the prior art, and the paper discharge means is independently provided corresponding to each of recording media of different types regarding presence or absence of ink permeability. Therefore, whichever recording medium is used, the inkjet printer can shorten the processing time without delaying a series of processes from printing to discharging, and thus can improve the processing efficiency of the inkjet printer as a whole. The purpose is to provide.

[0010]

In order to achieve the above-mentioned object, the ink jet printer of the present invention ejects hot melt type ink through an ink jet head onto respective recording media having different types of ink permeability. In an inkjet printer that prints characters and the like, and that heats a recording medium having no ink permeability after printing characters and the like by the inkjet head by a heating device, the type of the recording medium on the downstream side of the inkjet head According to the above, the sheet discharging means is independently arranged, and the heating device is provided in the sheet discharging path in the sheet discharging means for discharging the recording medium having no ink permeability.

[0011]

In the present invention having the above structure, when a recording medium having ink permeability is used, the recording medium on which characters and the like are printed by the hot melt type ink ejected from the ink jet head is the ink. The sheet is ejected to the outside of the printer from a sheet ejection unit provided exclusively for the recording medium having permeability.

When a recording medium having no ink permeability is used, the recording medium on which characters and the like are similarly printed by the ink jet head is designed to flatten the raised ink on the recording medium. After the heat treatment is performed, the recording medium having no ink permeability is ejected to the outside of the printer from the ejection unit provided exclusively for the recording medium.

At this time, in the case where the printing process and the discharging process of the recording medium having the ink permeability are performed during the heating process, the printing process and the discharging process on the recording medium have the ink permeability. Not performed regardless of the paper discharge process of the recording medium, the process is independently performed in parallel with the process. As a result, the printing process and the paper discharge process of the recording medium having the ink permeability can be performed without waiting for the end of the paper discharge process of the recording medium having the ink permeability.

[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 39 and 41 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 39,
Reference numeral 41 is for holding and positioning the print sheet 3 during printing by the inkjet head 13.

Next, downstream of the holding roller 41 of the printing section 11, a paper sheet discharging section A composed of a pair of discharging guide plates 17 and an OHP sheet discharging section composed of a pair of discharging guide plates 31 are also provided. The paper portion B and the paper portion B are arranged in a branched manner.
A paper discharge roller 19 and a pinch roller 21 pressed against the paper discharge roller 19 with a predetermined pressure are provided at the downstream end of the paper discharge guide plate 17, and the paper discharge roller 19 and the pinch roller 21 are mutually connected. The paper sheets guided by the paper ejection guide plate 17 by cooperation are sandwiched therebetween and ejected to the outside of the inkjet printer 1.

Similarly, a discharge roller 33 and a pinch roller 35 pressed against the discharge roller 33 with a predetermined pressure are provided at the downstream end of the discharge guide plate 31.
The paper discharge roller 33 and the pinch roller 35 cooperate with each other to discharge the paper to the outside of the inkjet printer 1 while sandwiching the OHP sheet guided by the paper discharge guide plate 31 therebetween.

A paper discharge tray 37 is provided below the paper discharge rollers 19 and 33, and the paper discharge rollers 19 are provided.
And the paper sheet discharged by the pinch roller 21 and the OHP discharged by the paper discharge roller 33 and the pinch roller 35
The sheets are stacked on the discharge tray 37.

A diverter 25 is rotatably arranged around a shaft 26 at a branch point between the two sheet discharge units A and B, and the diverter 25 forms a part of the sheet discharge units A and B. Based on the detection result by the sheet detector 23, it is switched between a solid line position (paper sheet discharge position) and a broken line position (OHP sheet discharge position) in FIG. 1 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 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 41 between the paper ejection guide plates 17 and ejected onto the paper ejection tray 37 by the paper ejection roller 19 and the pinch roller 21. It

When the print sheet 3 fed from the sheet feeding cassette 5 is detected by the sheet detector 23 as an OHP sheet, the diverter 25 is rotated about the shaft 26 and is broken by a broken line in FIG. The OHP sheet switched to the position and printed by the inkjet head 13 is guided from the holding roller 41 between the discharge guide plates 31, and is discharged by the discharge roller 33 and the pinch roller 35.
It is ejected on top.

Further, a heating device 27 is disposed in the middle of the discharge guide plate 31 of the OHP sheet discharging portion B, and the heating device 27 has three pairs of guide auxiliary rollers 43, 45, and 4.
7 and a heating platen 29 are provided. The guide auxiliary rollers 43, 45, and 47 cooperate with each other to guide the discharge of the OHP sheet discharged to the OHP sheet discharge section B, and the heating platen 29 is made of hot melt ink. The ink that is held at a temperature slightly higher than the melting point and is ejected onto the OHP sheet and solidified is heated again to perform the flattening process of the ink that is melted and raised.

Next, the operation of the ink jet printer 1 having the above structure will be described. First, when the print start switch is pressed, the paper feed roller 7 starts to rotate, and the uppermost print sheet 3 stacked in the paper feed cassette 5 moves toward the printing unit 11 via the paper feed guide 9. Sent. 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 the diverter 25 is rotated around the shaft 26 based on the detection result. The solid line position in FIG. 1 is switched to. After this, the paper sheet is placed on the sheet holding roller 3
The sheet 9 is pinched by 9 and fed upward, and is pinched by the other sheet holding roller 41 and supported by the platen 15.

Next, the ink jet head 13 is driven, and while the sheet holding rollers 39 and 41 feed the paper sheet upward, hot-melt type ink droplets of a predetermined color are ejected onto the paper sheet to print desired characters or the like. Is done. At this time, since the platen 15 has a built-in heater,
The hot melt type ink ejected onto the paper sheet promotes the penetration between the paper fibers of the paper sheet.

After the completion of printing, the paper sheet is sent between the paper discharge guide plates 17 while being guided by a part of the diverter 25 by the sheet holding roller 41, and then discharged by the cooperation of the paper discharge roller 19 and the pinch roller 21. The paper is discharged to the paper tray 37.

On the other hand, when the print sheet 3 fed from the sheet feeding cassette 5 via the sheet feeding roller 7 is an OHP sheet, the sheet detector 23 detects the transmission state of the light emitted from the light emitting diode 23a. Therefore, the diverter 25 is rotated around the shaft 26 based on the detection result and is switched to the position indicated by the broken line in FIG.

Thereafter, as in the case of the paper sheet, the OH
The P sheet is fed upward while being held by the sheet holding rollers 39 and 41 and is supported by the platen 15, and hot-melt type ink droplets are ejected onto the OHP sheet via the inkjet head 13 to perform desired printing of characters and the like. Be seen.

After the completion of printing, the OHP sheet is guided by the sheet holding roller 41 to a part of the diverter 25 and is fed between the discharge guide plates 31 and fed into the heating device 27. Further, the OHP sheet is a guide auxiliary roller 43,
The hot-melt ink, which is sent toward the heating platen 29 by the heating platen 45 and is ejected onto the OHP sheet and solidified in a raised state by the heating platen 29, is re-melted to perform the flattening process of the ink.

After the flattening of the ink by the heating platen 29, the OHP sheet is guided by the guide assist roller 47.
Is sent between the discharge guide plates 31 by the discharge rollers 33,
The paper is discharged to the paper discharge tray 37 in cooperation with the pinch roller 35.

The above-described flattening process of the ink by the heating platen 29 takes a relatively long time. However, when the printing process and the discharging process of the paper sheet are performed during the flattening process, this process is performed. In the example, the discharge guide plate 17 for the paper sheet and the discharge guide plate 31 for the OHP sheet are independently provided. Therefore, the diverter 25 is switched to the solid line position in FIG. Therefore, regardless of the above-described flattening process of the ink by the heating platen 29 and the discharge process of the discharge roller 33 and the pinch roller 35 of the OHP sheet, the print process and the discharge process of the paper sheet are performed in parallel with these processes. It can be carried out.

As described in detail above, in the ink jet printer 1 according to this embodiment, the sheet detector 23 detects the type of the print sheet 3, and for the paper sheet, the paper discharge guide plate 17, the paper discharge roller 19, Pinch roller 21
Further, for the OHP sheet, the paper ejection guide plate 31, the paper ejection roller 33, and the pinch roller 35 are independently provided, and the diverter 25 detects both paper ejection guide plates 17 and 31 based on the detection result of the sheet detector 23. Since one of them is selected, even when the paper sheet is printed and discharged during the flattening process of the ink by the heating platen 29 which takes a relatively long time, the flattening process and the discharge of the OHP sheet are performed. The printing processing and the paper discharging processing of the paper sheet can be performed in parallel with these processings regardless of the processings.

Therefore, unlike the conventional ink jet printer, 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. Can be totally improved without decreasing.

The present invention is not limited to the above embodiments, and various modifications and improvements can be added without departing from the spirit of the present invention. For example, in the example shown in FIG. 1, the paper discharge tray 37 is configured to be commonly used for both the paper sheet and the OHP sheet, but as shown in FIG. 2, the paper discharge tray 37 is used for the paper sheet. And OH
Needless to say, it may be configured separately for the P sheet discharge tray 37b.

Further, monochrome printing with an OHP sheet (black 1
In the case of color printing only, the diverter 25 is arranged at the position indicated by the solid line in FIG. On the other hand, only in the case of an OHP sheet and color printing, the diverter 25 is arranged at the position indicated by the broken line in FIG. 1, and the OHP sheet is ejected from the ejection roller 33 or the like to the ejection tray 37 via the heating device 27. As a result, monochrome printing OHP that does not require heat treatment
The sheet can be discharged onto the discharge tray 37 without performing the heat treatment, the processing time can be further shortened, and the processing efficiency can be totally improved.

[0042]

As described above, according to the present invention, any recording medium can be used by independently disposing the paper discharging means corresponding to each of the recording media of different types with respect to the presence or absence of ink permeability. Even in such a case, it is possible to provide an inkjet printer capable of shortening the processing time without delaying a series of processes from printing to discharging, and thus improving the processing efficiency of the inkjet printer in total. The effect of doing is great.

[Brief description of drawings]

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

FIG. 2 is a schematic cross-sectional view showing another embodiment of the paper discharge unit in the inkjet printer.

[Explanation of symbols]

 1 Inkjet Printer 3 Printing Sheet 11 Printing Section 13 Inkjet Head 15 Platen 17, 31 Paper Ejection Guide Plate 19, 33 Paper Ejection Roller 21, 35 Pinch Roller 23 Sheet Detector 25 Diverter 27 Heating Device 29 Heating Platen 37 Paper Ejection Tray

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 8804-2C B41J 29/00 H

Claims (1)

[Claims] 1. A character or the like is printed by ejecting a hot-melt type ink onto each of recording media of different types with respect to the presence or absence of ink permeability through an ink jet head, and after the character or the like is printed by the ink jet head. In an ink jet printer in which a recording medium having no ink permeability is heated by a heating device, a paper discharge means is independently provided according to the type of the recording medium on the downstream side of the ink jet head, and the ink permeation is performed. An inkjet printer characterized in that the heating device is provided in the middle of a paper discharge path of a paper discharge means for discharging a recording medium having no property.