JPH05220952A - Ink jet printing head - Google Patents

Abstract

PURPOSE:To efficiently supply a small quantity of heat in a short time to ink requiring a temperature control. CONSTITUTION:Ink is supplied from an ink flow path 3 to a pressure chamber surrounded by walls 14, 14, 14... and a vibrating plate 4. Ink drops are delivered from nozzle openings 2, 2, 2... by expanding and shrinking vibrators 9. A contact part 13 directly coming into contact with the ink in the ink flow path 3 is made of a member having a high thermal conductivity. A support member 7 is made of a member having a low thermal conductivity. In this manner, a supplied quantity of heat can be efficiently used for the temperature increase of the ink. Thus, a warming-up time can be shortened, and a quantity of heat to be supplied can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when a print signal is received, causes ink to fly as droplets from a nozzle opening onto a recording medium, and dots are formed on the recording medium by the ink droplets for printing. The present invention relates to an on-demand type inkjet print head.

[0002]

2. Description of the Related Art Ink requiring temperature control, that is, a hot-melt ink that is usually solid but changes to a liquid when the temperature rises, or a liquid that is usually liquid but changes in ink viscosity due to temperature change, The use of ink or the like that affects the ejection characteristics brings many advantages to the inkjet head, such as improved printing quality. On the other hand, in order to use such an ink, it is necessary to satisfy additional design requirements regarding the storage system and the flow path. Ink flow paths in ink jet print heads, such as ink jet printers, need to be designed so that all ink in and in the reservoir is maintained at a substantially constant and uniform temperature and the ink properties do not change. In the initial stage of use, it is desirable that the time (warm-up time) from when the power is turned on to reach a certain temperature is short and the power consumption is low. As an ink flow path already proposed for the purpose of satisfying these requirements, the ink flow path disclosed in Japanese Patent Laid-Open No. 63-297052 is known.

[0003]

Since the ink flow path of the conventional print head described above is made of a single material,
There has been a problem that it takes a long time from the start of supplying heat until the ink reaches a certain temperature. Further, since the amount of heat consumed for increasing the temperature of the ink flow path itself is large, there is a problem that the amount of heat supplied until the ink reaches a certain temperature is large.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ink jet type print head which can shorten the initial warm-up time and consumes less power. To do.

[0005]

In order to solve such a problem, in the present invention, an ink flow path is provided with a flow path member having a high thermal conductivity, which comes into contact with ink, and a heat supporting member for supporting the flow path member. It is composed of a support member having low conductivity.

[0006]

1 and 2 show an embodiment of an ink jet type print head according to the present invention. FIG. 1 is a perspective view of a main portion and FIG. 2 is a sectional view. In the figure, reference numeral 1 is a nozzle plate, which is manufactured by, for example, nickel electroforming or press working of a stainless plate, and is provided with a plurality of nozzle openings 2, 2 in a row in the paper feeding direction (X direction in the drawing). In addition, a plurality of such nozzle opening rows are arranged in the sub-scanning direction (Y direction in the drawing). The nozzle openings 2, 2, 2, ...
The ink is supplied from the ink flow paths 3, 3, 3 ... Provided on both sides as shown by an arrow A in FIG. Wall 14, 14, 14
Are manufactured, for example, by etching stainless steel foil and press, and are adhered or fused to a diaphragm 4 described later.

The ink flow path 3 is composed of a flow path member 13 and a support member 7 that supports the flow path member 13.
The support member 7 is fixed to the base 6. Flow path member 13
Is made of a metal plate having a high thermal conductivity, such as a stainless steel plate, and the supporting member 7 is made of a heat-resistant resin having a low thermal conductivity. The flow path member 13 and the support member 7 are integrally formed as in insert molding. Reference numeral 4 denotes the above-mentioned vibrating plate, which is made of a polyimide film or the like and has a nozzle plate 1
The pressure chambers 5, 5, 5 are formed between them and the nozzle plate 1 at a constant distance from each other and are fixed to the tip of the support member 7.

The ink flows into the pressure chamber 5 from the ink flow path 3 having a relatively small fluid resistance by the flow indicated by the arrow A in the figure. In order to smoothly supply the ink to the pressure chambers 5, 5, 5, that is, for the purpose of reducing the flow path resistance, it is desirable that the ink flow path 3 be as wide and deep as possible. However, due to downsizing of the head, a sufficient width and depth cannot be ensured. Therefore, it is desirable to reduce the width dimension that remarkably hinders downsizing and increase the depth instead.

On the other hand, in the ink jet type print head, when ink is ejected from all nozzles as in the case of full solid printing, if the flow path resistances of the ink flow paths 3, 3, 3 are large, the pressure chambers 5, 5, 5 are reached. Insufficient ink supply may occur, and the print quality may be impaired. In addition, the flow of ink becomes faster, and the temperature control of ink may not be in time. Therefore, as described above, it is necessary to deepen the depths of the ink flow paths 3, 3, 3 and at the same time to quickly supply the amount of heat to the ink filled in the ink flow paths 3, 3, 3.

In this embodiment, the flow path member 13 is made of a metal plate having a high thermal conductivity, and the supporting member 7 is made of a heat-resistant resin having a high heat insulating property (that is, a low heat conductivity). Has solved the problem.

Reference numeral 9 denotes a vibrator which is isolated from the ink and is divided into two upper and lower regions in the axial direction. On the inactive region side (lower side in the figure), substrates 10 and 11 made of a material having a larger acoustic impedance than the oscillator, such as alumina or metallic silicon, are adhered to both side surfaces thereof, and the substrates 10 and 11 are interposed therebetween. Is fixed to the base 6. On the other hand, the pressure transmitting member 12 is fixed to the tip of the active region of the vibrator 9, and is connected to the vibration plate 4 via the pressure transmitting member 12. By adopting such a configuration, when a voltage is applied to the vibrator 9, the vibrator 9 repeatedly expands and contracts,
Ink droplets can be ejected from the nozzle openings 2, 2, 2.

Further, a heater (not shown) is attached to the ink jet head in the vicinity of the above-mentioned flow path member 13, and the heater generates heat immediately after the power is turned on, and the ink jet head, especially the flow path member 13 and the ink. To start supplying heat. After that, the amount of heat is supplied until it reaches a certain temperature, and after reaching the certain temperature, only the amount of heat required to keep the temperature constant is supplied. According to the ink jet type print head of the present embodiment, the flow amount member 13 having high thermal conductivity which is in contact with the ink exchanges heat with the ink during the initial warm-up, and after the warm-up is completed. In order to maintain a constant temperature, the exchange of heat with the ink is repeated. Moreover, since the supporting member 7 is made of a heat-resistant resin having low thermal conductivity, the amount of heat supplied to the supporting member 7 can be small,
The amount of heat required for warming up is small, and therefore the time required to reach a certain temperature is shortened. Further, even when quick temperature control is required as in the above-described full solid printing, the amount of heat can be quickly supplied.

As described above, by constructing the flow path member 13 with a member having a high thermal conductivity and a small weight and volume, the amount of heat consumed by the flow path member 13 is greatly reduced and the time required for warming up is also increased. It is possible to shorten and to support all solid printing. Moreover, in the conventional no head,
Since the material of the flow channel / support member must be a material having good thermal conductivity, there were restrictions in processing and the flow channel depth was limited. However, it should be a composite member like the head of this embodiment. Thereby, the flow path member on the ink contact side can be manufactured by a material having good thermal conductivity, for example, by a processing method such as pressing, and the flow path can be deeper. Further, since the supporting member can be manufactured by insert molding of resin having low heat conductivity, the degree of freedom in shape is increased.

[0014]

According to the present invention, the ink flow path is constituted by the flow path member having high thermal conductivity and the supporting member having low heat conductivity, whereby the temperature can be effectively raised by the supplied heat amount. Therefore, the initial warm-up time can be shortened and the power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of an ink jet print head of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is an enlarged perspective view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle plate 2 Nozzle opening 3 Ink flow path 4 Vibration plate 5 Pressure chamber 6 Base 7 Support member 9 Vibrator 10, 11 Substrate 12 Pressure transmission member 13 Flow path member 14 Pressure chamber partition wall

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 2/055 9012-2C B41J 3/04 103 A

Claims (1)

[Claims] 1. An ink jet type print head which supplies ink, which requires temperature control, to a nozzle opening through an ink flow path and ejects it as an ink droplet from the nozzle opening, wherein the ink flow path is in contact with the ink through heat conduction. An ink jet type print head comprising a flow path member having high heat resistance and a support member having low thermal conductivity for supporting the flow path member.