JPH09193408A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer capable of shortening the so-called warm-up time required for melting the whole of the hot-melt ink in an ink tank. SOLUTION: When hot-melt ink is melted, a carriage motor is controlled while power is supplied to first and second ink melting heaters 11A, 11B heating the hot-melt ink in an ink tank 2 to reciprocally move a carriage 6 at a constant cycle within a constant range until the temp. of ink reaches predetermined temp. to apply vibration to the ink tank 2. By this constitution, the temp. distribution of the hot-melt ink during melting is made almost uniform in the ink tank 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer for heating and melting solid hot melt ink contained in an ink tank for printing.

[0002]

2. Description of the Related Art Conventionally, there is known an ink jet printer for hot melt ink which heats and melts hot melt ink contained in an ink tank to perform printing. It is equipped with a tank heater that heats the ink tank for melting, and such a tank heater has the purpose of melting the hot-melt ink that is once solidified due to power-off or the like when the power is turned on to start printing. It is used for the purpose of keeping the ink temperature of liquid ink in a molten state.

[0003]

In such an ink jet printer, when the hot melt ink is melted, the melted state becomes relatively fast in the vicinity of the heater and the temperature rises rapidly, but the melted portion is separated from the heater. However, there is a problem in that it takes a long time to bring the entire ink in the ink tank into a molten state. Further, in the process of melting the hot melt ink, there is a state in which solid ink which is not yet in a melted state and liquid ink which is already in a melted state are mixed. A temperature difference is generated in the melted liquid ink in the vicinity of the solid state hot melt ink, and the temperature distribution is biased. Therefore, in this process, the temperature of the hot melt ink cannot be accurately detected, and it is difficult to detect when the entire ink is in a molten state by the ink temperature. Therefore, it has been impossible to obtain an accurate timing for starting printing and to efficiently control the drive of the tank heater.

The present invention has been made in view of the above point, and can shorten the so-called warm-up time (ink melting waiting time) required to bring the entire hot melt ink in the ink tank into a molten state. It is an object to provide an inkjet printer.

[0005]

According to a first aspect of the present invention, there is provided an ink tank for containing hot melt ink supplied to a nozzle, and an ink melting heater for melting the hot melt ink in the ink tank into liquid ink. It is premised on an inkjet printer that performs printing with the melted liquid ink, and when vibrating means for imparting vibration to the ink tank, and when melting the hot melt ink in the ink tank, A control means for driving the vibration applying means to apply vibration to the ink tank while supplying electric power to the ink melting heater.

Therefore, according to the first aspect of the invention, when the hot melt ink in the ink tank is melted, the control means supplies the electric power to the ink melting heater and drives the vibration applying means to drive the ink. Vibration is applied to the tank, the temperature distribution of the hot melt ink during melting is made substantially uniform in the ink tank, and the melting of the hot melt ink in the ink tank is promoted. This shortens the warm-up time required for the entire hot melt ink in the ink tank to be in a molten state.

According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the ink tank is mounted on a movable carriage, and the vibration applying means moves the carriage in a constant cycle and in a constant range. The ink tank is reciprocated to apply vibration to the ink tank.

According to the second aspect of the present invention, the vibration applying means causes the carriage to reciprocate within a constant period and within a constant range, and the reciprocating movement of the carriage imparts vibration to the ink tank.

According to a third aspect of the present invention, in the ink jet printer according to the first or second aspect, there is further provided temperature detection means for detecting that the hot melt ink in the ink tank has reached a predetermined temperature, and the control is performed. The means receives the signal from the temperature detecting means, and operates the vibration applying means until the hot melt ink in the ink tank reaches a predetermined temperature.

According to the third aspect of the present invention, the control means controls the operation of the vibration applying means, and the vibration is applied to the ink tank until the hot melt ink in the ink tank reaches a predetermined temperature.

According to a fourth aspect of the invention, in the ink jet printer according to the first or second aspect, the control means has a timer means for measuring a fixed time, and when the hot melt ink in the ink tank is melted, The vibration applying means is operated for a certain period of time.

According to the fourth aspect of the invention, the operation of the vibration applying means is controlled by the control means, and the vibration is applied to the ink tank for a fixed time measured by the timer means.

According to a fifth aspect of the present invention, in the ink jet printer according to any one of the second to fourth aspects, further, there is a hollow portion disposed in a part of a moving range of the carriage and capable of accommodating at least the ink tank. A heat insulating member and a carriage transfer means for moving the carriage into the hollow portion of the heat insulating member when melting the hot melt ink in the ink tank are provided.

According to the fifth aspect of the invention, when the hot melt ink in the ink tank is melted, the carriage transfer means moves the ink tank together with the carriage in the hollow portion of the heat insulating member, and the heat insulating member insulates the ink tank. Due to the effect, melting of the hot melt ink in the ink tank is further promoted.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a main part of a hot melt type ink jet printer. In FIG.
The inkjet printer 1 heats and melts the solid hot-melt ink 3 contained in the ink tank 2,
An inkjet head 4 for printing on a printing sheet as liquid ink is provided, and the inkjet head 4 is mounted on a carriage 6 slidably provided along a guide bar 5 having a circular cross section extending in the left-right direction. .

The carriage 6 is attached and fixed to a carriage drive belt 7 wound around a pair of pulleys (not shown) arranged at regular intervals, and the carriage drive belt 7 is attached to the carriage motor 8. (See FIG. 2), whereby the inkjet head 4 is
By the reciprocating movement of the carriage 6, the carriage 6 is reciprocated in a printing area for printing on a printing paper. Therefore, the pair of pulleys, the carriage drive belt 7 and the carriage motor 8 constitute a carriage transfer means and a vibration applying means for applying a vibration to the ink tank 2, which will be described later.
A transport roller, which is rotationally driven by a transport motor (not shown) and transports the print paper, is arranged so that the axis line is substantially parallel to the reciprocating direction of the carriage 6, whereby the print paper reciprocates in the carriage 6. The ink is conveyed in a direction orthogonal to the moving direction, and liquid ink is ejected from the nozzles of the head portion 4a of the inkjet head 4 onto the printing paper for printing.

Further, the ink tank 2 is provided with an ink melting heater 11 (tank heater) for heating the solid hot melt ink 3 in the ink tank 2 (see FIG. 2). Specifically, the ink melting heater 11 is composed of a first heater 11A arranged at the bottom of the ink tank 2 and a second heater 11B arranged at the top. Further, a thermistor 12 (temperature detecting means) for detecting that the hot melt ink 3 in the ink tank 2 has reached a predetermined temperature is arranged in the vicinity of the first heater 11A and substantially in the center in the moving direction of the carriage 6. Has been done. Here, the “predetermined temperature” means the temperature when it is determined that all the hot melt ink 3 in the ink tank 2 is melted, and is experimentally obtained. Specifically, the temperature is higher than the melting temperature of the hot melt ink 3.

Since the ink tank 2 is made of an aluminum alloy having excellent thermal conductivity, the thermistor 12 is arranged near the first heater 11A and substantially in the center in the moving direction of the carriage 6. If so, the temperature can be controlled.

On the upper side of the ink jet head 4,
A head cover 13 is attached. In addition to the guide bar 5, an engaging member 15 that engages with a guide plate 14 that guides the movement of the carriage 6 is also provided. Further, the inkjet head 4 including the ink tank 2 is
While the printing is stopped, the carriage 6 is retracted to the retracted position in the hollow portion of the heat insulating member 16 which is made of foamed resin or the like and is disposed at a lateral position which is a part of the moving range of the carriage 6, and the ink tank 2 Inkjet head 4 including
The heat radiation is suppressed.

Next, a control system for controlling the drive of the carriage 6 when the hot melt ink 3 in the ink tank 2 is melted will be described.

As shown in FIG. 2, during a normal printing operation, the CPU 22 drives and controls the carriage motor 8 through the motor control circuit 21 to move the carriage 6 back and forth within the printing area. . When the CPU 22 receives a signal from the thermistor 12 and melts the hot melt ink 3 in the ink tank 2, the CPU 22 supplies electric power to the ink melting heater 11 (first and second heaters 11A and 11B). On the other hand, until the hot melt ink 3 reaches a predetermined temperature, the carriage motor 8 constituting the carriage transfer means is driven to reciprocate the carriage 6 in a fixed cycle and in a fixed range, and the ink tank 2 is vibrated. The melting of the hot melt ink 3 in the ink tank 2 is promoted.

With the above construction, when the hot-melt ink which has been once solidified due to the power cut or the like is melted, the ink tank 2 is heated by the ink melting heater 11 and the carriage motor 8 is driven by the motor by the CPU 22. Controlled via the control circuit 21, the carriage 6 is reciprocated in a fixed cycle and in a fixed range, vibration is applied to the ink tank 2, and in this state, the hot melt ink 3 in the ink tank 2 reaches a predetermined temperature. And the melting of the hot melt ink 3 is promoted.

That is, as shown in FIG. 3, when the hot melt ink 3 is melted (specifically, the warm-up is determined based on the temperature signal from the thermistor 12 and it is determined that the ink temperature is low and needs to be melted). CPU22
An ON signal is output by the motor control circuit 21, and a pulse signal in which a forward rotation pulse and a reverse rotation pulse are repeated at a constant cycle T in the motor control circuit 21 is output to the carriage motor 8, which causes the carriage 6 to reciprocate within a predetermined range to cause an ink tank. Vibration is applied to 2. When the thermistor 12 determines that the hot melt ink 3 in the ink tank 2 has reached a predetermined temperature, the CPU 22 outputs an OFF signal, and the motor control circuit 21 stops driving the carriage motor 8.

By applying the vibration in this way, the temperature distribution of the hot melt ink 3 in the ink tank 2 in the state where the solid ink and the liquid ink are mixed in the middle of the melting process, in the ink tank 2 , Is made substantially uniform, the melting of the hot melt ink 3 in the solid ink state is promoted, and the warm-up time required until the entire hot melt ink 3 in the ink tank 2 is melted to become the liquid state is shortened. It Therefore, it is possible to obtain an accurate timing for starting printing and efficiently control the driving of the ink melting heater 11.

It should be noted that, when ink is being melted in a state where solid ink and liquid ink are mixed, under the condition that the same electric power is applied to the ink melting heater 11, when vibration is applied, vibration is applied more than when vibration is not applied. Also, the temperature difference between the solid ink and the liquid ink mixed in the ink tank 2 becomes small, and as a result, the amount of heat radiated into the air and the amount of heat taken by the carriage 6 and the like are reduced, and the hot melt ink 3 melts. It is advantageous in promoting.

Next, a specific control flow by the CPU 22 will be described with reference to FIG.

Hot melt ink 3 in the ink tank 2
In the warm-up state in which the ink is in a solid state, when starting by receiving print data, first, the ink melting heater 11 (first and second heaters 11A and 11B) is energized (step S1), and the ink melting heater 11 causes the ink to melt. The hot melt ink 3 in the tank 2 is heated, and the hot melt ink 3 in the ink tank 2 starts to melt.

Then, the carriage motor 8 is driven based on the pulse signal from the motor control circuit 21, and the carriage 6 is reciprocated left and right in a constant cycle and in a constant range via the carriage drive belt 7 (step S).
2), vibration is applied to the ink tank 2. Specifically, for example, the vibration (reciprocating motion) of the carriage 6 has an amplitude of 5 m.
m, the cycle T of vibration is 1 cycle / 1 sec. It is said.

Then, it is judged whether or not the ink thermistor 12 for measuring the temperature corresponding to the ink temperature of the hot melt ink 3 in the ink tank 2 has reached a predetermined temperature (for example, 125 ° C.) (step S3), If the temperature of the hot melt ink 3 in the ink tank 2
Is determined to be in a liquid state by melting all of the ink. Therefore, in order to maintain the liquid state, the ink melting heater 1
The normal temperature control of No. 1 is started (step S4), and the control at the time of warm-up is ended. On the other hand, if the temperature does not reach the predetermined temperature, it is necessary to continue the control at the time of warm-up. , The left and right reciprocating movements of the carriage 6 are continued.

When the ink temperature of the hot melt ink 3 in the ink tank 2 reaches a predetermined temperature and printing is started, the temperature is controlled as shown in FIG. 5 and the decrease in ink temperature is suppressed.

When starting by receiving print data,
The printing paper is sucked (step S11), printing is performed by the inkjet head 4 based on the printing data (step S12), and after the printing is completed, the printing paper after the printing is discharged (step S13), The carriage motor 8 is driven to move the carriage 6 to the retracted position (heat insulating portion) (step S14), and the inkjet head 4 and the carriage 6 together with the heat insulating member 16 are moved.
It is housed inside and insulated, and hot melt ink 3
The heat dissipation from the ink jet head 4 including the ink tank 2 is suppressed so that it is advantageous to maintain the melted state, and the process ends.

In the above embodiment, it is detected that the hot melt ink 3 in the ink tank 2 has reached a predetermined temperature, and it is determined that the hot melt ink 3 is melted and is in a liquid state. However, the fixed time required to melt all of the hot melt ink in the ink tank by applying vibration (obtained by experiment)
In order to melt the hot melt ink, a timer means for measuring is used to reciprocate the carriage for a certain period of time in a certain period and a certain range as in the case described above.
Vibration can be applied to the ink tank.

Further, in the above-described embodiment, after the ink temperature of the hot melt ink 3 in the ink tank 2 reaches a predetermined temperature and printing is started, in order to suppress the decrease of the ink temperature, after the printing is completed, When the printing paper is discharged, the carriage 6 is moved into the hollow portion of the heat insulating member 16. However, when the hot melt ink 3 in the ink tank 2 is melted, the carriage 6 is insulated by the carriage transfer means. The melting of the hot melt ink can be further promoted by moving it into the hollow portion of the member 16.

[0035]

As described above, according to the first aspect of the present invention, when the control means melts the hot melt ink in the ink tank, electric power is supplied to the ink melting heater while the ink tank vibrates. Since it is applied, the temperature distribution of the hot melt ink during melting is made substantially uniform in the ink tank, the melting of the hot melt ink is promoted, and the entire hot melt ink in the ink tank becomes a molten state. The warm-up time required can be shortened. Therefore, it is possible to obtain an accurate print start timing and efficiently control the driving of the ink melting heater.

According to the second aspect of the present invention, the carriage is reciprocated within a certain range, and the ink tank is vibrated by the reciprocating movement of the carriage. Therefore, the vibration can be easily applied to the ink tank. You can

According to the third aspect of the invention, since the ink tank is vibrated until the temperature reaches a predetermined temperature,
The hot melt ink can be efficiently melted.

According to the fourth aspect of the invention, since the ink tank is vibrated for a certain period of time, the ink tank is vibrated for a certain period of time until the hot melt ink in the ink tank is melted, so that the hot tank can be easily heated. Melt ink can be melted.

According to the fifth aspect of the present invention, when the hot melt ink in the ink tank is melted, the carriage is moved into the hollow portion of the heat insulating member. It can be promoted more.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of an inkjet printer according to the present invention.

FIG. 2 is a block diagram of a control system according to the present invention.

FIG. 3 is a time chart diagram of motor control according to the present invention.

FIG. 4 is a flowchart showing a control flow according to the present invention.

FIG. 5 is a flowchart showing a control flow according to the present invention.

[Explanation of symbols]

 1 Inkjet Printer 2 Ink Tank 3 Hot Melt Ink 4 Inkjet Head 6 Carriage 8 Carriage Motor 11 Ink Melting Heater 12 Thermistor 16 Thermal Insulation Member

Claims (5)

[Claims] 1. An ink tank for containing hot melt ink to be supplied to a nozzle, and an ink melting heater for melting the hot melt ink in the ink tank to form liquid ink are provided. In an inkjet printer that performs printing, a vibration applying unit that applies vibration to the ink tank, and the vibration applying unit while supplying power to the ink melting heater when melting the hot melt ink in the ink tank. And a control unit for driving the ink tank to apply vibration to the ink tank. 2. The ink tank is mounted on a movable carriage, and the vibration applying unit applies vibration to the ink tank by reciprocating the carriage in a constant cycle and in a constant range. The inkjet printer according to claim 1, wherein 3. A temperature detecting means for detecting that the hot melt ink in the ink tank has reached a predetermined temperature, and the control means receives a signal from the temperature detecting means,
The inkjet printer according to claim 1 or 2, wherein the vibration applying means is operated until the hot melt ink in the ink tank reaches a predetermined temperature. 4. The control means has a timer means for measuring a fixed time, and when the hot melt ink in the ink tank is melted, the vibration applying means is operated for a fixed time. The inkjet printer according to claim 1 or 2. 5. A heat insulating member having a hollow portion arranged in a part of a moving range of the carriage and capable of accommodating at least the ink tank; and when melting the hot melt ink in the ink tank, A carriage transfer means for moving the carriage into the hollow portion of the heat insulating member.
The inkjet printer according to any one of 4 above.