JPH01290429A - Liquid ejection recording device - Google Patents

Abstract

PURPOSE:To set a heating temperature which allows liquid droplets for recording to be fixed optimally and minimize the deformation and discoloration of recording paper by providing a heating temperature control means which changes the temperature of the heating temperature. CONSTITUTION:If a heater temperature-setting command is transferred from a host device 20, and a heater temperature is set at a high temperature T1, a heater 11 which heats recording paper 9 is controlled at the constant temperature T1. In addition, if a heater setting temperature is set at a low temperature T2 by a heater temperature selector switch, the surface temperature of the heater 11 is maintained at the temperature T2. Consequently, it is possible to set a heating temperature at which liquid droplets for recording are fixed to the recording paper in an optimum state in accordance with the difference in the fixing property of the recording paper, or ambient environments. Furthermore, it is possible to limit the deformation and discoloration of the recording paper by a heating means to a minimum extent under a simple constitution and at low cost.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid jet recording device.

[Prior Art J Conventionally, in a liquid jet recording device that performs recording by jetting recording droplets such as ink onto a recording medium such as recording paper or an OHP film sheet, it is difficult to record on plain paper other than specific coated paper. In order to shorten the time it takes for the recording droplets to fix, a heating means such as a heater is often installed to heat the recording paper after recording and evaporate the moisture in the recording droplets. In this case, the heater should be equipped with a temperature detection means such as a thermistor, and the heater temperature and paper feed speed should be controlled to always be kept at a constant value after the device is powered on, regardless of the surrounding environment or the type of recording paper. was common.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, the temperature on the heater is constant regardless of the difference in fixing performance of the recording paper depending on the paper thickness, surface condition, etc., or the surrounding environment. There was a problem in that it was not possible to set the optimum heating temperature for each recording paper.

In particular, when the surrounding environment is high temperature and the recording paper is thin, the stretched recording paper containing a large amount of moisture is rapidly heated on the heater and the moisture evaporates, causing it to shrink and become deformed. This is large, and there is a risk that printing misalignment may occur in the row direction (main scanning direction) or the like, and that this may lead to paper feeding defects such as paper jams.

An object of the present invention is to be able to set a heating temperature that optimizes the fixation of recording droplets to the recording paper according to the difference in fixability of the recording paper and the surrounding environment, and to fix the recording paper using a heating means. It is an object of the present invention to provide an inexpensive liquid jet recording device with a simple configuration that can minimize deformation and discoloration.

[Means for Solving the Problems J] In order to achieve the above object, the present invention provides a liquid jet recording apparatus having a heating means for promoting the fixation of recording droplets attached to a recording medium. The device is characterized in that it includes heating temperature control means for changing the heating temperature.

[Function] According to the above configuration, the optimum heating temperature can be set according to the situation by the heating temperature control means.

[Example] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 5 is a perspective view showing the external configuration of an inkjet recording apparatus according to the present invention, in which 1 is a head for ejecting ink;
is a carriage that carries the head 1 and moves in the recording line direction (main scanning direction).

The carriage 2 is slidably supported by a guide shaft 3.4, engages a timing belt 8, and reciprocates in the recording line direction. The timing belt 8, which is engaged with the pulleys 6.7, is driven by the carriage motor 5 via the pulley 7.

The recording paper 9 is guided by a vapor pan IO and conveyed by a paper feed roller (not shown) that is pressed against a pinch roller. This conveyance is carried out by the paper feed motor 16.
is used as a driving source. The conveyed recording paper 9 is under tension by a paper ejection roller 13 and a spur 14, and is pressed against the heater 11 by a paper pressing plate 12 formed of an elastic member, so that it is not brought into close contact with the heater 11. It is transported while being held in place. The recording paper 9 on which the ink ejected by the head 1 has adhered is heated by the heater 11, and the water in the adhered ink evaporates and is fixed on the recording paper 9.

Reference numeral 15 denotes a unit called a recovery system, which supplies ink to the nozzles (not shown) of the head 1 and removes foreign matter adhering to the nozzles and ink with increased viscosity.
This is to maintain the discharge characteristics in a normal state. Although not shown, on the key panel provided on the exterior of this recording device, there is a heater temperature changeover switch 3, which will be described later.
2 is provided.

FIG. 1 is a block diagram of a control system in the apparatus shown in FIG. In the figure, 21 is a central processing unit (CPU) composed of a microprocessor element and the like that controls the operation of the entire inkjet recording apparatus. The data to be recorded and the commands that control the operation of the recording device are
The data is transferred from the host device 20, such as a computer system, to the CPt 121 via the recording data receiving section 22, which is constituted by a known interface circuit such as a parallel interface or a serial interface.

Based on the transferred data, the CPυ 21 controls the head 1 via the head control section 23 and head drive section 24 . The drive timing of the head 1 is controlled to a predetermined value by using a timer 25.

When the print data transferred from the host device 20 is characters or symbols, the data is transferred in the form of a character code, so the printing device converts it into dot image data so that it can be printed with a dot matrix printing head l. converted. For this conversion, the character generator ROM
(CGROM) 26 is provided. Also CPU2
The control program to be processed by 1 is the control ROM
It is stored in 27.

Furthermore, RAM 2 is used as a buffer area for the transferred recording data or a work area for the CPU 21.
8 is provided.

In addition, an input port 29 composed of flip-flop elements and the like is provided for detecting various switches and sensors, and an output port 30 is provided for outputting control signals for mechanical mechanisms such as the carriage motor 5. An output signal from a heater temperature changeover switch 32 provided on the key panel on the exterior of the recording device is input to this input boat 29.
Further, the output boat 30 outputs a heater temperature switching signal to the heater temperature control circuit 31.

FIG. 2 is a circuit diagram showing the configuration of the heater temperature control circuit 31. This heater temperature control circuit 31 controls a primary side heater drive circuit by a secondary side control circuit insulated by a photocoupler 47, and temperature detection of the heater 11 is performed by a thermistor 42. . The temperature of the heater 11 can be selected from two types: high temperature and low temperature.

A heater 11 is connected to the ten input terminals of the comparators 40 and 41.
A voltage VIN divided by a thermistor 42 and a resistor R1 attached to the terminal is manually applied. vrefl+ is connected to one input terminal of the comparator 40;
1, Vraf2 is input as a reference voltage to each input terminal. Reference voltage vr @ f l r V
r @ f 2 corresponds to the high temperature T1 and low temperature T2 of the heater temperature, respectively, and the heater set temperature T1 on the high temperature side
It is determined that VIN=Vref2 at the heater setting temperature T2 on the low temperature side by v+NWVref1%. (T
I>Tz, VraLl>vr@r2) The outputs of the comparators 40 and 41 are AND43, 44. A data selection circuit consisting of an inverter 45 and a NOR 46 is powered manually. Output boat 3 shown in the first diagram
According to the level of the signal output from 0, this data select circuit determines whether to select the output of comparator 40 or the output of comparator 41.

The primary side, which is insulated from the secondary side by the photocoupler 47, is a heater drive circuit, and when the transistor of the photocoupler 47 is OFF, the gate of the thyristor 48 is configured with a resistor R3 and a capacitor C1, and a phase circuit is connected to the gate of the thyristor 48. As a result, a current whose phase is ahead of the power supply voltage flows, so that the thyristor 48
is turned on at the beginning of the positive half cycle, ie at 0(v), to supply mold force to the heater 11 during the positive half cycle of the power supply voltage.

When the transistor of the photocoupler 47 is ON, no gate current flows to the gate of the thyristor 48.
8 is not triggered. Therefore, no power is supplied to the heater 11. Note that resistor R4 is thyristor 4.
This is to prevent erroneous triggering of 8 due to noise.

Next, the operation of this circuit will be explained. Now, the heater temperature is set to the high temperature side (TI
), the heater temperature switching signal output from the output boat 3o becomes "H" level. As a result, the output of the inverter 45, that is, one of the inputs of the AND 44 becomes a "high" level, and the output of the comparator 41 becomes N0.
It no longer affects the output of R46. Therefore N0R46
is determined solely by the output of comparator 40.

Now, when the temperature of the heater 11 is below the temperature T, the VIN
<VraLl, so the output of the comparator 4o becomes "L" level. Therefore, the output of ANo43 is “L”
The level and the output of the N0R46 become "H" level, and no current flows through the photodiode of the photocoupler 47. As a result, the transistor of the photocoupler 47 becomes OFF.
The switch becomes FF, and an open current of a positive half wave of the power supply voltage flows through the heater 11, and the temperature of the heater 11 rises. As the temperature of the heater 11 increases, the resistance value of the thermistor 42 on the heater 11 decreases, and when the heater temperature exceeds the temperature T, VIN
>It becomes VraLl. As a result, the output of the comparator 40 changes from the "L" level to the "H" level, and the N0R46
The output changes from “H” level to L” level. N08
When the output of 4B becomes "L" level, a current limited by the resistor R2 flows through the photodiode of the photocoupler 47 connected to the output of N01146, and the transistor of the photocoupler 47 is turned on. When the transistor is turned on, no current flows through the gate of the thyristor 48, so power is not supplied to the heater 11 and the temperature of the heater 11 decreases. By repeating the above operations, the heater 11 is controlled to a constant temperature T1.

Next, when the heater temperature changeover switch 32 sets the heater temperature to the low temperature side (T2), the heater temperature changeover signal goes to the "L" level. and AND43
The output of is fixed at "L" level.

Therefore, the output of the comparator 40 does not affect the output of the N0R46, and only the output of the comparator 41 affects the output of the N0R46.
This will determine the output of As a result, power is not supplied to the heater 11 until the temperature of the heater 11, which has been controlled to the temperature T1, becomes equal to or lower than T, which is lower than T1. When the temperature of the heater 11 becomes lower than the temperature T2, the surface temperature of the heater 11 is maintained at the temperature T2 by the same control as when maintaining the temperature T.

Next, the operation of this embodiment configured as described above will be explained according to the flowchart shown in FIG.

First, after turning on the power of the apparatus, in step 5lot, the heater temperature switching signal is set to "H" level to set the heater temperature to the high temperature side (T1). Next, in step 5102, the RAM
The heater temperature flag X provided at 28 is set to "1".

In step 5103, it is determined whether the recording device is in a state where it can accept data from the host device (online state), and when it is in the online state, it receives recording data from the host device and performs a recording operation in step 5104, and in step 51
Jump to 03. As long as such an online state continues, the heater temperature is maintained at the high temperature side (T1).

When it is determined in step 5103 that the offline state is off, the process proceeds to step 5105, where the output of the heater temperature changeover switch 32 is detected, and when the switch is pressed, the heater temperature flag X is set to X in step 5106. Invert. When the heater temperature changeover switch 32 is not pressed in step 5105, the heater temperature flag X is held as it is.

Next, in step 5107, heater temperature flag X is detected. When X=1, the heater temperature switching signal is set to "H" level to set the heater temperature to the high temperature side (T,), and when X=O, the heater temperature switching signal is set to "L" level to set the heater temperature. is set to the low temperature side (T2).The heater temperature is controlled according to this heater temperature switching signal.After setting the heater temperature in step 5108 or step 5109, the process jumps to step 5103.In this way, the offline state continues. As long as 0, each time the heater temperature changeover switch 32 is pressed, the heater temperature flag Each time the heater temperature changeover switch 32 is pressed, the set temperature of the heater surface can be changed from high temperature to low temperature to high temperature to low temperature.
In high humidity conditions where the recording paper contains a large amount of water, the optimum heater temperature can be set at the discretion of the operator of the recording device, such as by selecting the lower temperature side.

In addition, in the embodiment described above, the heater setting temperature is a high temperature product, Mr. Lee? Although there are two modes in A, it is clear that this mode can be increased to three or more modes.

FIG. 4 is a flowchart showing the control procedure of an embodiment in which the heater set temperature is changed by a command from the host device.

After powering on the device, the heater temperature switching signal is set to “H” level in step 5201 to set the heater surface to the high temperature side (T,
). Next, in step 5202, wait until the system becomes online, and then manually input data from the host device (step 5203). It is determined in step 5204 whether or not there is a heater high temperature setting command in the manual data from the host device, and if it is input, step 52 is performed.
Proceeding to step 05, the heater temperature switching signal is set to "H" level. Also, the presence or absence of the heater low temperature setting command is determined in step 5.
If it is determined in step 206 and the heater low temperature setting command is manually input, the heater temperature switching signal is set in step 5207.
L" level to keep the surface temperature of the heater on the low temperature side (T2). With the surface temperature of the heater thus set, a recording operation is performed in step 520B, and the process jumps to step 202. Repeat the same action.

By performing the above control, it becomes possible to set the temperature of the heater surface to two modes, high temperature and low temperature, by a heater temperature setting command from the host device. In addition, by increasing the types of commands or parameters, 3
It is possible to set the heater surface temperature higher than the modulus. Therefore, when this embodiment is equipped with a cut sheet feeder, if the type of paper set changes midway through, the configuration should be such that the type of paper is detected and the heater temperature is automatically changed. I can do it.

[Effects of the Invention] As explained above, according to the present invention, the heating temperature can be set to optimize the fixing of recording droplets to the recording paper depending on the difference in fixing properties of the recording paper and the surrounding environment. Therefore, deformation and discoloration of the recording paper caused by the heating means can be minimized with a simple configuration and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention; FIG. 2 is a circuit diagram showing the configuration of a heater temperature control circuit; FIG. 3 is a flowchart showing the control procedure of an embodiment of the present invention; FIG. 4 is a flowchart showing the control procedure of another embodiment of the present invention, and FIG. 5 is a perspective view showing the external configuration of the inkjet recording apparatus according to the present invention. 1... Recording head, 9... Recording paper, 11... Heater, 21... CPII. 31... Heater temperature control circuit, 32... Heater temperature changeover switch.

Claims (1)

[Scope of Claims] 1) A liquid jet recording apparatus having a heating means for promoting fixation of recording droplets attached to a recording medium, further comprising a heating temperature control means for changing the temperature of the heating means. A liquid jet recording device.