EP0446918A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Thermal ink-jet printhead having improved heater arrangement

Assignee: NEC Corp

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Filing: 1991-03-14

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Granted: —

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Expires: 2011-03-14

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Abstract

Abstract A thermal ink-jet type printhead is disclosed which comprises a strip-like thin metallic layer (54) formed on a substrate (52). The layer (54) is configured so as to define a narrow portion (56) which is positioned between broad portions (58a, 58b). The narrow portion (56) defines a heating element which is integral with the broad portions (58a, 58b) which act as electrodes. Electrical Heating pulses are supplied to the narrow heater portion (56) via the electrodes. The heater arrangement (50) is durable to thermal stresses generated by a superheating and, accordingly is well suited for spontaneous or homogeneous nucleation.

Inventors

👤 Kikukazu C/O Nec Corporation Sakurai
👤 Mitsuo C/O Nec Corporation Tsuzuki

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-03 16:53

CPC Classifications

B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/14; B41J2/14016; B41J2/14088; B41J2/14112; B41J2/1412; B41J2002/14387; B41J2202/00; B41J2202/01; B41J2202/11

Claims Analysis

Total Claims: 5

Claim 1

Independent Claim 69 words

A heater arrangement for use in a thermal ink-jet type printhead, comprising: a substrate; a thin metallic layer formed on said substrate, said thin metallic layer being configured so as to define a narrow portion which is located between broad portions, the narrow portion defining a heating element which is integral with the broad portions which act as electrodes via which currents are supplied to the narrow heater portion.

Claim 2

Dependent Claim 27 words

A heater arrangement as claimed in claim 1, wherein said narrow portion has end portions which gradually and outwardly expand and are integrated with the broad portions.

Claim 3

Dependent Claim 91 words

A thermal ink-jet type print head having an orifice plate in which at least one orifice is formed; a substrate which is disposed adjacent the orifice plate in a manner to define a space in which ink can be supplied; and a metallic layer formed on the surface of said substrate so as to be exposed to said space, said metallic layer defining integral heater element and electrodes, said heater element being configured such that the width of said heater element is narrower than the width of each of the electrodes.

Claim 4

Dependent Claim 26 words

A print head as claimed in claim 3, wherein said heater element has end portions which gradually and outwardly expand and are integrated with said electrodes.

Claim 5

Dependent Claim 156 words

In a method of operating a thermal ink-jet type print head which includes a substrate, a strip-like thin metallic layer formed on said substrate, said strip-like thin metallic layer being configured so as to define a narrow portion which is located between broad portions, the narrow portion defining a heating element which is integral with the broad portions which act as electrodes via which currents are supplied to the narrow heater portion, the steps of: applying a current to the heating element in a manner to heat the same in a range from 10⁶ to 10⁹ °C/sec so as to transfer heat energy from the heating element to an ink at a rate of 10⁷ to 10⁸ MW/m² over a time period less than 10 µs and to achieve homogeneous nucleation via which a bubble of gas is produced and induces a droplet of ink to be ejected from a nozzle located adjacent the heating element.

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