JPH04358839A - inkjet printer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is an ink that is solid at room temperature (
The present invention relates to an inkjet printer that forms an ink image on a recording medium such as recording paper by heating and melting hot melt ink and causing ink droplets to fly. More specifically, the present invention relates to raising and keeping the temperature of the inkjet head portion of the apparatus.

0002

2. Description of the Related Art In general, an inkjet recording apparatus using hot melt ink has the advantage of being highly compatible with paper types and free from clogging due to ink evaporation during periods of rest. However, due to the principle of using ink by changing its phase from solid to liquid, it is necessary to raise the temperature of the inkjet head to a temperature higher than the melting point of the ink and maintain it at a predetermined temperature. Conventionally, therefore, a heater installed inside the inkjet head was used to raise and maintain the temperature.

0003

[Problems to be Solved by the Invention] In order to shorten the warm-up time, the temperature must be raised quickly, but a large amount of electric power is required to raise the temperature quickly. When obtaining a large amount of power, using primary power reduces the burden on the power supply of the device and reduces power supply costs. However, when an inkjet head performs serial scanning, there is a safety problem in applying primary power to a cable connected to the inkjet head. On the other hand, when secondary power is used, the power supply becomes larger and the cost increases if a large amount of power is to be obtained. Therefore, in order to reduce power supply costs, the temperature was raised over time using small amounts of electricity. This is inconvenient because the user has to wait a long time after turning on the power until it becomes possible to record.

[0004] The purpose of the present invention is to solve the above problems and
To provide an inkjet printer that shortens the temperature rise time when turning on the power without putting a burden on the power supply.

[0005]

[Means for Solving the Problems] The inkjet printer of the present invention is a serial type printer that records by heating and melting ink that is solid at room temperature and ejecting ink droplets from a plurality of nozzles onto a recording medium being conveyed. The inkjet printer has a first heater provided at a predetermined position in the printer and a second heater provided in the inkjet head, which heats an inkjet head on a carriage, and a second heater provided in the inkjet head.
It is characterized in that primary side power is supplied to the heater, and secondary side power is supplied to the second heater.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing a schematic configuration of an inkjet printer according to an embodiment of the present invention. Recording paper 1 is
It is inserted along the paper guide 2 and is held between the paper feed roller 3 and the paper press roller 4. A paper feed motor 5 rotates a paper feed roller 3 via a motor pinion 6 and a paper feed gear 7. A carriage 21 carrying an inkjet head 11 reciprocates along a guide shaft 26. A belt 24 drives the carriage 21 using the carriage motor 22 as a power source. 23 is a drive pulley directly connected to the carriage motor 22. 25 is an idler pulley that applies tension to the belt 24. 12 is an ink supply port. 13 is an FPC (flexible printed circuit board) that follows the movement of the inkjet head 11. F
The PC 13 is connected to the inkjet head 11 at one end and to the control circuit via the connector 14 at the other end.

[0007] 31 is a first heater. 32 is an AC cable that supplies primary power to the first heater 31. 33 is a heat transfer member made of an aluminum alloy with good thermal conductivity. The heat transfer member 33 applies heat from the first heater 31 to the inkjet head 11 in close contact with the heat transfer member 33 from the top and side surfaces.

FIG. 2 is a sectional view of the inkjet head 11 shown in FIG. 1. The inkjet head 11 is made of aluminum alloy with good thermal conductivity, and has a second heater 4 at the bottom.
1. The second heater 41 is connected to the FPC 13 on the side surface of the inkjet head 11 (not shown). The heat generated by the second heater 41 is controlled by a temperature sensor 42 to maintain the inkjet head 11 at a predetermined temperature.

Reference numeral 52 denotes an ink melting chamber, which converts the charged solid ink 62 into liquefied ink 61. Ink melting chamber 52
is equipped with a filter 51 on the lower surface. The filter 51 removes dust and transfers the liquefied ink 61 to the inkjet head 1.
Store within 1. 53 is an ink sensor that senses the presence or absence of liquefied ink 61. 57 is a piezoelectric transducer. About half of the piezoelectric transducer 57 in the longitudinal direction is fixed to the base 58, and the end portion is electrically connected to the FPC 13. The remaining half of the piezoelectric transducer 57 is unconstrained and expands and contracts in response to the electric field. The tip of the piezoelectric transducer 57 that expands and contracts is connected to an elastic plate 56.
are connected to each other. The elastic plate 56 has a plurality of nozzles 5
It faces the nozzle plate 54 with a small gap therebetween. Due to the capillary force between this gap, the liquefied ink 6
1 is sucked up and filled.

The ink droplet ejection operation will be explained. Figure 2
At this point, an electric field is applied to the piezoelectric transducer 57 through the FPC 13. This causes the piezoelectric transducer 57 to contract. next,
Release this electric field. Piezoelectric transducer 57 stretches and returns to its original length. This causes a volume change in the gap portion surrounded by the nozzle plate 54 and the elastic plate 56, and ink droplets are ejected from the nozzle 55.

The recording operation will be explained. First, when the power is turned on, as shown in FIG. 1, the carriage motor 22 rotates and moves the carriage 21 so that the inkjet head 11 comes into close contact with the heat transfer member 33.

Next, primary power is applied to the first heater 31 through the AC cable 32. The first heater 31 and the heat transfer member 33 quickly reach a high temperature and heat the inkjet head 11 from the outside. At the same time, the second heater 41
Also, secondary power is applied through the FPC 13 to generate heat, thereby heating the inkjet head 11 from within. In this embodiment, approximately 400 watts of power is applied to the first heater 31 and approximately 20 watts of power is applied to the second heater 41. When the temperature of the inkjet head 11 rises and the temperature sensor 42 determines that it has reached a predetermined temperature, the power to the first heater 31 is turned off. Further, the carriage 21 is moved to release the heat transfer member 33 and the inkjet head 11 from close contact.

Thereafter, the inkjet head 11 is maintained at a predetermined temperature only by heating by the second heater 41. Next, the presence or absence of liquefied ink 61 is checked using the ink sensor 53. If the ink sensor 53 determines that there is no liquefied ink, it issues an ink end signal and waits for the solid ink 62 to be replenished. If the ink sensor 53 determines that liquefied ink 61 is present, preparation is complete. After the warm-up is completed in this manner, recording is performed by repeating the above-described ink droplet ejection operation while moving the carriage 21 and transporting the recording paper 1 by rotating the paper feed roller 3 in accordance with the recording signal.

[0014]

As explained above, in the inkjet printer of the present invention, since the temperature of the inkjet head is quickly raised using the power on the primary side, the power supply only needs to supply power to the second heater. Therefore, the power supply cost is low and it is safe.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the inkjet head of the same embodiment.

[Explanation of symbols]

11 Inkjet head 21 Carriage 31 First heater 41 Second heater 61 Liquefied ink

Claims (2)

[Claims] 1. In an inkjet printer that records by heating and melting ink that is solid at room temperature and ejecting ink droplets from a plurality of nozzles onto a conveyed recording medium, heating an inkjet head on a carriage. An inkjet printer comprising: a first heater provided at a predetermined position within the printer; and a second heater provided within an inkjet head. 2. An inkjet printer according to claim 1, wherein the first heater is supplied with primary power, and the second heater is supplied with secondary power.