JPH01110962A - inkjet recording device - Google Patents

Abstract

PURPOSE:To prevent discoloring or creasing of a sheet, as well as to prevent insufficient drying of the same even when spaces between lines printed are relatively wide by setting a period of time when the sheet stays on a fixing heater substantially constant. CONSTITUTION:Once a recording sheet 5 is placed on a fixing heater 6 comprising a heating plate or the like, the recording sheet 5 is designed to be transferred over the fixing heater 6 at constant speed, i.e. over the period of time since it touches the fixing heater 6 until it has passed over the heater. Thus, the invention is designed to set a period of time when the sheet 5 stays on the fixing heater 6 substantially constant. In this construction, therefore, even when printing is ceased due to the lack of the reception of data or the like, discoloring and creasing of the sheet 5 can be prevented. Moreover, even when spaces between lines printed are relatively wide, insufficient drying of ink can be prevented. A fixing heater control section 28 is designed to control the fixing heater 6 via a heater driver 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ink jet recording apparatus having a fixing heater that heats a sheet after recording to accelerate drying of ink.

[Conventional technology]

An inkjet recording device drives an inkjet head having an ink ejection orifice based on print data, and causes flying ink droplets from the ink ejection orifice to adhere to a sheet (print paper, etc.) to create an image consisting of a pattern of printed dots. It is to be recorded.

In conventional inkjet recording apparatuses, the density of printed dots is relatively low, and the amount of adhered ink is not very large.

However, in recent years, as computer processing power has improved, there has been a demand for improved quality of images such as characters that are output (recorded).

Therefore, in recording devices, progress is being made in the direction of printing out images such as characters of higher quality by increasing the density of printing dots (for example, 48 dots).

By the way, in an inkjet recording device, when the dot density increases, the amount of ink ejected onto the sheet (printing paper, etc.) during printing increases, and as a result, images such as printed characters become difficult to dry, making it difficult to print. Inconveniences may occur, such as the written characters being rubbed and disturbed, and various parts being stained.

Therefore, it is conceivable to use a fixing heater that heats the sheet after recording to accelerate the drying of the ink.

This fixing heater can be configured, for example, by a hot plate installed on the discharge side (swaft side) of the recording head and also serving as a sheet guide.

[Problem that the invention seeks to solve]

By the way, in an inkjet recording device that uses a hot plate as described above to speed up the drying of ink, if printing is interrupted midway and the sheet (paper) is left in the center, the sheet may become discolored. Or, if the part that is in contact with the hot plate is heated for a longer time than other parts, phenomena such as shrinkage in that part and wrinkles in the sheet occur.

On the other hand, if the time for the sheet to pass through the hot plate is short, for example, if the spacing between printed lines is wide, the time the sheet is in contact with the hot plate is short, and the ink is not sufficiently dried and printed. The printed sheet may be rubbed, causing the characters to become disorganized or smudged.

[Means for Solving the Problems] The present invention has been made in view of the problems of the prior art described above. In an ink shared recording device equipped with a fixing heater, printing is interrupted midway due to reasons such as data reception being stopped. An inkjet recording device that can prevent discoloration and wrinkles on the sheet even when the sheet is interrupted, and can also prevent ink from drying insufficiently even when the printed line spacing (white area) is wide. The purpose is to provide

The present invention achieves the above object by using an inkjet recording apparatus having a fixing heater that heats the sheet after recording to accelerate the drying of the ink, by making the time that the sheet is on the fixing heater substantially constant. be.

〔Example〕

The present invention will be specifically described below with reference to the drawings.

FIG. 2 is a schematic longitudinal cross-sectional view of an ink-side recording apparatus according to an embodiment of the present invention.

In FIG. 2, pinch rollers 2.3 are disposed at two places on the lower circumferential surface of the sheet (paper) feed roller 1 so as to be able to come into contact with and separate from each other. ) A recording head (inkjet head) 4 is arranged.

A sheet 5 inserted (supplied) from the direction of arrow A is fed between a sheet feed roller 1 and a pinch roller 2 pressed against the sheet feed roller 1, and after passing through the pinch roller 2, the sheet 5 is further fed between the sheet feed roller 1 and the pinch roller 3. These pinch rollers 2
．． 3, the feed roller 1 is brought into close contact with the circumferential surface of the feed roller 1.
Q feed force is given.

While the sheet 5 is fed by the feed roller 1 at a predetermined pitch to the front surface of the recording head 4 (the front surface of the ink ejection port), ink droplets are attached to the surface of the sheet 5 to form a predetermined pattern of printed dots for recording. To go.

A hot plate (
A fixing heater 6 composed of a real plate) is installed.

The fixing heater 6 contacts the back surface of the sheet 5 and heats the sheet 5 after recording to accelerate the drying of the ink.
It is arranged to guide the conveyance of the sheet.

The sheet 5 after recording passes through the fixing heater 6 and is then discharged in the direction of arrow B.

The fixing heater 6 may be, for example, a structure containing an electrothermal converter such as a heating resistor, a member made of the electrothermal converter itself, or a member heated by heat exchange with the electrothermal converter. Various configurations can be used, such as a structure containing a medium (water, gas, etc.).

However, the inkjet recording apparatus according to the present invention includes a fixing heater 6 that heats the sheet 5 after recording to promote drying of the ink, and the sheet 5 is provided with the fixing heater 6.
It is configured so that the time at the top is approximately constant.

FIG. 1 is a block diagram of the control system of the ink shared recording apparatus according to the present invention.

In FIG. 1, a central processing unit (CPU or control circuit) 21 of an inkjet recording apparatus is connected via a DATA signal line 22 and an ADDRESS signal line 23 to a ROM 24 storing a control program and a character phono I, and a receive buffer. A RAM 2 (i) having a register and a print buffer register is connected to a recording operation control section 27, a fixing heater control section 28, and a data reception section 29, and various data from the host computer 30 are sent via the data reception section 29. It is taken in at the specified timing.

The recording operation control section 27 controls each operation during recording (printing), and in the illustrated example, the head driver 3
1 to the recording head 4, and an LF (line feed) to the recording head 4 via the LFM (line feed motor) driver 32.
The motor 33 is configured to control a CR (carriage) motor 35 via a CRM (carriage motor) driver 34, respectively.

Further, the fixing heater control section 28 controls the fixing heater 6 via a heater driver 36.

Various data, such as command data and character (image) data, are transmitted from the host computer 30 via the data receiving section, and the CPU 21 controls the recording head 4, sheet feed motor 33, and carriage based on these data. It controls the operation of the recording mechanism section including the motor 35, fixing heater 6, and the like.

According to the control system of FIG. 1 according to the present invention, the time period during which the sheet 5 (FIG. 2) is on the fixing heater 6 is kept approximately constant during the printing operation. That is, when printing, when the sheet 5 is placed on the fixing heater 6,
The fixing heater 6 is configured to feed the sheet 5 at a uniform pitch at a speed corresponding to the predetermined time period from the time the sheet 5 touches the fixing heater 6 until the sheet 5 finishes passing through the fixing heater 6.

FIG. 3 is a flowchart showing an operating procedure for controlling the sheet 5 to pass over the fixing heater 6 at a constant speed in the control system of FIG.

In FIG. 3, in step 101 the data receiving section 29 (
1), step 102
This data is stored in the receive buffer register of RAM 2G (FIG. 1).

Next, in step 103, it is determined whether or not a command signal for the chest after one page of printing has been received, that is, a form feed command.

If the form feed command has not been received, the process returns to step 101 and the aforementioned data reception is repeated.

When a form feed command is received, the process advances to step 104 to determine whether the received data is character data.

If it is character data, proceed to step 105 and store it in the ROM.
The corresponding character font is bit expanded from 24 to the print buffer register of RAM 26, and the process returns to step 104.
Go back and repeat this.

If it is not character data, the process advances to step 106 and it is determined whether there is a sheet feed command (line feed command).

If there is no sheet feed command, the process returns to step 104 and determines whether the next data is character data.
Repeat the above operation again.

If there is a sheet feed command, proceed to step 107 and press R.
Check whether there is data in the print buffer register of AM26.

If there is data, one line is printed in step 108 and the process proceeds to step 109; if there is no data, the process directly proceeds to step 109 without printing.

In step 109, it is determined whether maximum width printing has been performed. That is, it is determined whether all the digits of one line have been printed or only some of the digits of one line have been printed.

When the maximum width printing is performed, the process advances to step 110 and the sheet is fed by one line.

If the maximum width is not printed, the process proceeds to step 111 for a time hold, that is, waits for a time to keep the sheet feeding speed constant, and then proceeds to step 110 to feed the sheet by one line. The above-mentioned waiting time is performed for a time corresponding to the difference in time required between maximum width printing and other cases.

After feeding the sheet by one line, proceed to step 112 and
It is determined whether printing for one page has been completed.

If one page has been printed, the process advances to step 113 and sheet 5 (FIG. 2) is discharged.

If printing for one page has not been completed, the process returns to step 104 and each of the above steps (step 104 to step 1) is completed.
10. Repeat step 111).

According to the embodiment described above, when the recording sheet 5 is placed on the fixing heater 6 composed of a hot plate or the like, the recording sheet is kept uniformly from the time the recording sheet touches the fixing heater until it finishes passing through the fixing heater. The configuration is such that the time that the sheet 5 remains on the fixing heater 6 is set to be approximately constant each time the sheet is fed (line fed) at the speed.

Therefore, even when printing is interrupted due to data reception stopping, etc., it is possible to prevent discoloration and wrinkles on the sheet 5, and furthermore, even when the printed line spacing (white area) is wide, the ink does not dry out. It has become possible to prevent this from becoming insufficient.

Although the present invention has been specifically explained based on the embodiments above, the present invention is applicable to an inkjet recording device using a printing method such as a serial printing type or a line printing type, or an inkjet head such as monochrome printing or color printing. It is widely applicable regardless of the number of sheets or the type of sheet used, such as cut sheets or fan-fold sheets.

[Effects of the Invention] As is clear from the above description, according to the present invention, in an inkjet recording apparatus that includes a fixing heater that heats the sheet after recording to prevent ink from drying, the time period during which the sheet is on the fixing heater is reduced. Since the ink is configured to be approximately constant, it is possible to prevent discoloration and wrinkles on the sheet, and to obtain an inkjet recording device that can prevent the ink from drying insufficiently even when the printed line spacing is wide. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control system of an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of main parts of an inkjet recording apparatus according to an embodiment of the present invention. ! The sectional view and FIG. 3 are flowcharts showing the operating procedure of the control system of FIG. 1. 1・−・−・−・Sheet feed roller, 4−・−−−
--- Recording head, 5----- Sheet,
6.--.--Fuser heater, 21-.-
−−−−−−CPU, 24−・−−−−−=
=ROM, 26-------RAM. Agent Patent Attorney Yasutake Ooto

Claims (1)

[Claims] (1) An inkjet recording device having a fixing heater that heats the sheet after recording to accelerate the drying of the ink, characterized in that the time the sheet is on the fixing heater is kept approximately constant.