Inspection apparatus and method for liquid discharge head and liquid discharge head

Patent metadata

Field	Value
Publication number	US-9555653-B2
Application number	US-201615049787-A
Country	US
Kind code	B2
Filing date	Feb 22, 2016
Priority date	Mar 3, 2015
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

An apparatus for inspecting a liquid discharge head including an energy generation element provided on an element substrate and configured to make energy act on a liquid to discharge the liquid from an orifice, a lower protection film having an electrical insulating property and provided on the element substrate while covering the energy generation element, a wiring layer provided between the element substrate and the lower protection film and configured to supply electrical signal for driving to the energy generation element, and a conductive upper protection film provided on the lower protection film is provided. The apparatus comprises a detection circuit configured to detect a potential of the upper protection film when the energy generation element is driven; and a determination circuit configured to determine a driving state of the energy generation element from information about the potential detected by the detection circuit.

First claim

What is claimed is:

1. An inspection apparatus for inspecting a liquid discharge head including an energy generation element configured to generate energy for discharging liquid, a wiring layer for supplying an electrical signal to the energy generation element, the wiring layer including a first wiring connected to one end of the energy generation element and a second wiring connected to the other end of the energy generation element, a first conductive protection film extending from the first wiring to the second wiring, and a second protection film having an electrical insulating property and provided between the wiring layer and the first protection film, comprising:
a detection circuit configured to detect a potential of the first protection film when the electrical signal is supplied to the energy generation element; and
a determination circuit configured to determine a driving state of the energy generation element from information about the potential detected by the detection circuit.

2. The apparatus according to claim 1 , wherein the first protection film is electrically separated into a first portion arranged in correspondence with a position where the energy generation element is formed and a second portion arranged in correspondence with a position where the wiring layer is formed, and
the detection circuit is electrically connected to the second portion and detects a potential of the second portion.

3. The apparatus according to claim 1 , wherein the information detected by the detection circuit is information of a potential change detected when the energy generation element of an inspection target is driven by the electrical signal.

4. The apparatus according to claim 3 , wherein the determination circuit determines that the energy generation element is normal when the potential change falls within a predetermined range, and determines that the energy generation element is defective when the potential change falls outside the predetermined range.

5. The apparatus according to claim 3 , further comprising a control circuit configured to control the electrical signal for driving and pulse-drive the energy generation element,
wherein the determination circuit determines that the energy generation element is disconnected when a magnitude of the potential change between a period before the energy generation element is pulse-driven and a period in which the energy generation element is being pulse-driven is not more than a first threshold, and determines that the energy generation element is partially ruptured when the magnitude of the potential change between the period before the energy generation element is pulse-driven and a period after the pulse driving has ended is not less than a second threshold.

6. An inspection method for inspecting a liquid discharge head including an energy generation element configured to generate energy for discharging liquid, a wiring layer for supplying an electrical signal to the energy generation element, the wiring layer including a first wiring connected to one end of the energy generation element and a second wiring connected to the other end of the energy generation element, a first conductive protection film extending from the first wiring to the second wiring, and a second protection film having an electrical insulating property and provided between the wiring layer and the first protection film, comprising:
detecting a first potential of the first protection film when the electrical signal is not supplied to the energy generation element;
supplying the electrical signal for driving the energy generation element;
detecting a second potential of the first protection film when the electrical signal is supplied to the energy generation element; and
determining a driving state of the energy generation element based on information about the first potential and the second potential.

7. The method according to claim 6 , further comprising:
stopping supplying the electrical signal after detecting the second potential of the first protection film; and
detecting a third potential of the first protection film after stopping supplying of the electrical signal,
wherein the determining includes determining the driving state of the energy generation element based on information about the first potential, the second potential and the third potential.

8. A liquid discharge head comprising:
an energy generation element configured to generate energy for discharging liquid;
a wiring layer for supplying an electrical signal to the energy generation element, the wiring layer including a first wiring connected to one end of the energy generation element and a second wiring connected to the other end of the energy generation element;
a first conductive protection film extending from the first wiring to the second wiring;
a second protection film having an electrical insulating property and provided between the wiring layer and the first protection film; and
a terminal configured to electrically connect to the first protection film.

9. The liquid discharge head according to claim 8 , wherein the liquid is ink.

10. The liquid discharge head according to claim 9 , wherein the liquid discharge head is an inkjet print head.

11. The liquid discharge head according to claim 8 , wherein the energy generation element is a resistive heating element.

12. The liquid discharge head according to claim 8 , wherein the first protection film is electrically separated into a first portion arranged in correspondence with a position where the energy generation element is formed and a second portion arranged in correspondence with a position where the wiring layer is formed, and
wherein the first portion includes an anti-cavitation film configured to protect the energy generation element from cavitation.

13. The liquid discharge head according to claim 8 , wherein an insulation film is provided between the first wiring and the second wiring.

14. The liquid discharge head according to claim 8 , wherein the wiring layer, the first protection film and the second protection film are formed on a surface of a silicon substrate fixed to ground potential.

Assignees

• Canon Kk

Inventors

• Kanno Hideo

Classifications

• B41J29/393 Primary

  Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} · CPC title

• B41J2/04555 Primary

  detecting current · CPC title

• B41J2/04576

  controlling heads of electrostatic type · CPC title

• B41J2/04561

  detecting presence or properties of a drop in flight · CPC title

• B41J2/04588

  using a specific waveform · CPC title