JPH03162966A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To prevent a decrease in the throughput of a recorder, an increase in power consumption at the time of controlling an ink temperature by disposing heating means near a discharge port, controlling the means synchronously with the operation of a motor at the starting time of recording, and controlling the operating time of the means in response to an environmental temperature. CONSTITUTION:Heating means (temperature insulating heater) 19 is disposed near an ink discharge port 17, ink in the port 17 is heated from the interior of a recording head 12, thermal capacity at a part to be heated is reduced, and the temperature of a discharging ink is controlled at a high speed. If ink heating time is set by referring to a table for allocating conducting time in response to the temperature, it can be simply realized by a software. Thus, a decrease in the throughput of a recorder, an increase in power consumption at the time of controlling the ink temperature do not occur. Further, recording ink can be controlled at a suitable temperature in a short time even at the time of low temperature with a simple structure with needs no excess member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording apparatus that performs recording by ejecting and flying ink droplets from an ejection port of a recording head and making the droplets adhere to a recording material.

[Conventional technology]

Recording devices such as printers, copiers, and facsimile machines convert dots and patterns onto recording sheets such as paper and thin plastic plates by driving the energy generator of the recording head based on the transferred image information. It is configured to record images that appear on the screen.

The recording apparatuses can be divided into inkjet 1 type, wired soto type, thermal type, laser beam type, etc., depending on the recording method. Among these, the inkjet 1 type (inkjet soto recording device) uses the inkjet 1 type (inkjet soto recording device) to It is configured to eject ink and make it adhere to a recording sheet for recording.

2. Description of the Related Art An inkjet recording apparatus performs recording by ejecting recording liquid (ink) droplets from an ejection port and adhering them to a recording material such as paper.

Inkjet 7 that uses heat as energy for ejecting ink droplets
In a conventional recording device, an ejection port is provided on the front surface of the print head, and a liquid path is formed inside the print head from a common liquid chamber to the ejection port, and an electrothermal transducer placed in the liquid path is energized to inject ink. By heating, the ink undergoes a state change accompanied by a rapid increase in volume, and is configured to eject and fly ink droplets from the ejection ports.

The electrothermal transducer is energized based on an image (recording) signal.

Since inkjet recording devices use liquid ink, the recording quality is strongly influenced by the characteristics of the ink. In particular, the viscosity of ink is important because it affects ejection characteristics such as ejected droplet diameter and ejection speed.

Generally, the viscosity of ink correlates with temperature and tends to increase as the temperature decreases, and ejection failure is likely to occur at low temperatures.

In a bubble jet recording head that uses an electrothermal converter (discharge heater) as an ink discharge energy generating means, the ink temperature near and within the ink discharge ports increases by about 10 degrees or more due to the ink discharge operation.

Therefore, even at low temperatures, if the ejection operation is performed continuously, the ejection conditions will gradually improve, but the temperature due to the ejection operation will only gradually rise, so immediately after the start of printing, there will be no ink ejection or the recording density will decrease. If the density is uneven, the recording quality will deteriorate.

Therefore, in the conventional inkjeso I recording apparatus, by providing a heating means (thermal heater) outside the recording head, the ink inside the recording head or in the ink supply path is heated, and the viscosity of the ink at low temperature is increased. A method has been adopted to prevent this increase and obtain a good ink ejection condition.

[Technical Problems to be Solved by the Invention] However, in the conventional example 11, since the heat-retaining heater is provided outside the recording head, the heat capacity of the heated portion is large;
The ejection ink temperature did not rise to the appropriate temperature until a relatively long period of time, for example, several minutes, had elapsed since the heating was started.

Therefore, even if you start energizing the heat-retaining heater at the same time as recording starts, it will take time for the ink to reach the appropriate ejection temperature, and the temperature distribution within the heated part will change even after you stop energizing the heat-retaining heater. There was a technical problem in that recording could not be started until after some time had elapsed, and the throughput of the recording device was significantly reduced at low temperatures.

Therefore, when the temperature is low, a control method may be considered in which the ink temperature is maintained at a predetermined value by energizing the heat-retaining heater during a standby period in which the printing apparatus is waiting for a signal from the host computer.

However, with this type of control method, for example, there are cases where there are consecutive line breaks without recording between the end of recording one line and the start of recording the next line, or when multiple pages are recorded continuously. There is a technical problem in that when a page change operation is performed, the temperature of the ink decreases due to natural cooling, and the effect of the heat-retaining heater is lost.

In order to solve this technical problem, it is necessary to detect continuous line feeds and page feeds using software, for example.
It is necessary to control the heat retention heater, which increases the burden on the software and reduces the throughput of the recording device.
・This will lead to a decrease in

On the other hand, with the above-mentioned control method in which the ink is preheated during the standby period of the recording device, if the standby period becomes relatively long, the increase in power consumption cannot be ignored, and furthermore, the ink may be heated continuously for a long time. This also causes a problem that the durability of the surrounding members of the heat-retaining heater is reduced.

The present invention has been made in view of the above-mentioned conventional technical problems, and does not cause a decrease in the sloop of the recording device or an increase in power consumption during ink temperature control, and further,
The purpose of the present invention is to provide an inkgeno 1 recording device that has a simple structure that does not require any extra members and is capable of controlling the recording ink temperature to rise to an appropriate value in a short time even at low temperatures. .

[Means to solve the problem]

The present invention provides an inkjet recording apparatus configured to heat the recording medium to raise the ink temperature at low temperatures, in which the heating means is disposed near the ejection port, and the heating means is arranged in the vicinity of the ejection port to control the operation of the motor at the start of recording. By controlling the heating means in synchronization and controlling the operating time of the heating means in accordance with the environmental temperature, the throughput of the recording apparatus is not reduced and the power consumption during ink temperature control is not increased. Moreover, it has a simple structure that does not require any extra parts,
An object of the present invention is to provide an inkjet 1/recording apparatus that can control the temperature of recording ink to be raised to an appropriate value in a short time even at low temperatures.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to the drawings.

FIG. 2 is a partial perspective view showing the ejection opening portion of the recording head 1- of the inkjet recording apparatus according to the present invention.

In FIG. 2, a plurality of ejection ports 17 are formed at a predetermined pitch in the vertical direction on the surface of the recording head 12 facing the recording material. An electrothermal transducer (discharge heater) 18 such as a heating resistor that generates droplet discharge energy is provided in the droplet discharge section.

Bubbles are generated in the ink by driving (energizing) the ejection heater of each ejection port l7 based on the 18 recording information.
is generated, and its expansion pressure forms flying ink droplets, and recording is performed while the droplets adhere to the recording material.

A heating stage 19 is arranged near the ejection port 17 to adjust the ink temperature within each ejection port 17 to within a proper ejection temperature range before ejection.

This heating stage 19 is composed of a heat-retaining heater such as a heating resistor.

According to the present invention, as shown in FIG. 2, the heating means (thermal heater) I9 is arranged near the ink ejection port 17,
Since the ink in the ejection ports 17 is heated from inside the recording head 12, the heat capacity of the heated portion is small, and the temperature of the ink for ejection can be controlled at high speed.

FIG. 3 is a block diagram showing a configuration example of a control system of an inkjet recording apparatus according to the present invention.

In the figure, 1 is a programmable peripheral interface (hereinafter referred to as PPI), which receives command signals (commands) and recording information signals sent from the host computer in parallel and transfers them to the MPU 2, as well as controlling and controlling the console 6. Carriage home position sensor 7
Performs input processing.

The MPU (microprocessing unit 1) 2 controls each section within the recording apparatus and performs the processing procedure shown in FIG. 1, which will be described later.

3 is a RAM for storing received signals, 4 is a font generation ROM that outputs images such as characters and symbols, and 5 is an MP
A control ROM in which a processing procedure (FIG. 1) executed by Ll2 is stored is shown.

Each of these parts is connected to an address bus 21 and a data bus 2.
2, respectively.

8 is a carriage motor for moving the carriage;
Reference numeral 10 denotes a sheet feed motor for conveying the recording material in a direction perpendicular to the moving direction of the carriage.

l5 is a dryer for driving the carriage motor 8;
1G is a dryer for driving the sea 1/feed remoter 10.

The six consoles are provided with keyboard switches, indicator lamps, and the like.

The home position sensor 7 is provided near the home position of the carriage and detects when the carriage on which the recording head 12 is mounted has reached the home position.

Further, numeral 9 indicates a sheet sensor that detects the presence or absence of a recording material such as recording paper, that is, whether or not it is supplied to the recording section.

The recording head l2 includes an ejection port (FIG. 2) 17, an ejection heater (FIG. 2) 18, a heat retention heater (heating means) 19,
A temperature detection element 20 and the like are provided.

Reference numeral 11 indicates a driver for driving the ejection heater 18 of the recording head 12 in response to a recording information signal, and 14 indicates a driver for driving the heat-retaining heater 19.

In the above structure, the MPU 2 is connected to a host device such as a computer via the PPTl, and receives commands and recording information signals sent from the host device and programs stored in the control ROM 5. The recording operation is controlled based on the processing procedure of and the data in RAM a.

FIG. 1 is a flowchart of the recording operation of the inkjet recording apparatus according to the present invention.

In FIG. 1, when the recording apparatus is powered on, hardware and software are initialized in step 31 as initial processing.

After completing the initial processing in step S1, the recording device enters a state in which it can receive a signal sent from the host device (online state) in step S2, and while determining whether or not there is recording start information, stand by.

In the online state, if there is recording start information such as a command signal or recording information signal transmitted from the host device, the process advances to step S3, where the driver 15 starts driving the carriage motor 8 (starts ramping up), and the motor The rotation speed continues to accelerate until it reaches a steady state.

In this embodiment, by controlling the heat-retaining heater 19 in synchronization with this lamp amplifier operation, the process of determining the start and end timing of ink temperature control by software is omitted, and the burden on the software 1 and software is eliminated. can be reduced.

When the lamp amplifier of the carriage motor 8 is started in step S3, at the same time, the ink temperature is detected by the temperature detection element 20 in step S4, and at the same time, in step S
In step 5, it is determined whether the ink temperature is lower than the set value.

If the determination result is YES (low temperature), a time period for heating the ink is set in step S6, and in step S7, the heating means (thermal heater) 19 is activated by the driver 14.
The ink inside the ejection port 17 is heated by applying electricity to the ink.

The ink heating time can be easily set using software by referring to a table in which energization times are assigned according to temperature. This table is stored in the control ROM 5 and is created so that the lower the temperature is, the longer the energizing time is, so that the ink temperature after heating is almost constant regardless of the ambient temperature.

After the above-mentioned ink heating is completed, and the ramp-up of the carriage motor 8 is completed in step S8, the carriage motor 8
When the rotational speed reaches a steady state, the process proceeds to step S9, and the driver 1l is driven based on the recorded data,
The discharge heater 18 is supplied with a drive power source (heat voltage. For example, 25
V, ) is applied to eject ink and record one line on the recording material.

−4, in step S5, the ambient temperature (ink temperature)
If it is determined that the temperature is higher than the set value, the heat retention heater 19 is not energized, and after the rotation speed of the carriage motor 8 reaches a steady state (S8), the rotation speed for one line is Make a record.

By ejecting ink according to the procedure described above, the ink temperature immediately before the start of ejection can be quickly controlled to a range suitable for ink ejection using only software control.

Therefore, it has become possible to easily and reliably prevent deterioration of image quality due to non-ejection of ink or decrease in recording density at low temperatures without reducing the recording speed.

Furthermore, since ink temperature control at the start of printing can be executed at high speed, the power consumption required for ink temperature control can be reduced accordingly.

Furthermore, since the heating stage 19 for ink temperature control is controlled in synchronization with the motor operation at the start of recording, it is possible to control the ink temperature without adding hardware, resulting in a simple and compact structure. It also had the effect of being able to be carried out.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in the Inkgen 1 recording apparatus configured to heat the recording head at low temperatures to raise the ink temperature, the heating means is disposed near the ejection port. Then, the heating means is activated in synchronization with the operation of the motor at the start of recording! In addition to controlling the ink temperature, the operation time of the heating means is also controlled in accordance with the environmental temperature, so there is no reduction in the throughput of the printing apparatus or an increase in power consumption when controlling the ink temperature. With a simple structure that does not require any extra parts,
An ink jet recording device is proposed that can control recording ink to the appropriate temperature in a short time even at low temperatures. be done.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a flowchart illustrating the operation of the inkjet recording apparatus according to the present invention at the start of recording, and FIG. FIG. 3 is a partial perspective view illustrating the structure, and FIG. 3 is a block diagram illustrating the structure of the control system of the inkjet recording apparatus according to the present invention. 2. -MPU, 5-----Control ROM
, 8----- Carriage motor, 10----- Sheet conveyance motor, 12 Recording head, 14-111 Heating means (thermal heater) tricycle, 15-- Carriage Motor dryer, 16---- Sea 1/Feed motor driver, 17 discharge port, 18- Discharge heater, 19--Heating means (thermal insulation heater), 20-
-----Temperature detection means.

Claims (1)

[Claims] In an inkjet recording apparatus configured to raise the ink temperature by heating the recording head at low temperatures, the heating means is disposed near the ejection port, and the heating means is activated in synchronization with the operation of the motor at the start of recording. An inkjet recording apparatus characterized in that the operating time of the heating means is controlled according to the environmental temperature.