Back to results
US 2004/0070650 A1Published application
Pressure producing apparatus
AssigneeBrother Kogyo Kabushiki Kaisha
InventorHiroto Sugahara
Life of this patent
Estimating the term…
Abstract
Cylindrical electrodes are embedded in a piezoelectric sheet of an actuator unit. An axial length of each of the electrodes is somewhat shorter than half a thickness of the piezoelectric sheet, and accordingly the electrodes do not penetrate through the sheet. The piezoelectric sheet is polarized in a surface direction parallel to a surface thereof. When the electrodes take a positive potential, an electric field is applied to the piezoelectric sheet in the surface direction, the actuator unit including the piezoelectric sheet is so curved as to swell upward, because there is produced a difference between respective amounts of extension in the surface direction of an upper portion of the sheet in which the electrodes are provided and a lower portion of the same in which no electrodes are provided.
Claims23
A pressure producing apparatus, comprising:
- a sheet member which is formed of a piezoelectric material;
- at least one first electrode which is embedded in one of a first portion and a second portion of the sheet member, the first portion and the second portion being opposite to each other in a direction of thickness of the sheet member;
- and
- at least one second electrode which is embedded in said one of the first and second portions of the sheet member, such that said at least one second electrode is opposed to said at least one first electrode in a surface direction parallel to one of a first surface of the first portion and a second surface of the second portion, the first surface and the second surface being opposite to each other in the direction of thickness of the sheet member.
1 more element
A pressure producing apparatus, comprising:
- a first sheet member which is formed of a piezoelectric material;
- at least one first electrode which is embedded in the first sheet member;
- at least one second electrode which is embedded in the first sheet member such that said at least one second electrode is opposed to said at least one first electrode in a surface direction parallel to a first surface of the first sheet member;
- and
- a second sheet member which is stacked on the first sheet member and resists elongation of the first sheet member in the surface direction that occurs when an electric field is applied, in the surface direction, to a portion of the first sheet member that is located between said at least one first electrode and said at least one second electrode.
2 more elements
A pressure producing apparatus, comprising:
- a sheet member which is formed of a piezoelectric material;
- at least one first electrode which is embedded in at least one of a first portion and a second portion of the sheet member, the first portion and the second portion being opposite to each other in a direction of thickness of the sheet member;
- at least one second electrode which is embedded in said at least one of the first and second portions of the sheet member, such that said at least one second electrode is opposed to said at least one first electrode in a surface direction parallel to a first surface of the first portion and a second surface of the second portion that are opposite to each other in the direction of thickness of the sheet member;
- and
- a liquid-chamber defining member which cooperates with one of the first and second surfaces of the sheet member to define a liquid chamber in which a liquid is accommodated,
- wherein an electric field is applied between said at least one first electrode and said at least one second electrode, so as to produce a difference between an amount of elongation in the surface direction of the first portion of the sheet member and an amount of elongation in the surface direction of the second portion of the sheet member and thereby curve the sheet member in the direction of thickness thereof and change a pressure of the liquid accommodated in the liquid chamber.
3 more elements
A pressure producing apparatus, comprising:
- a first sheet member and a second sheet member which are stacked on each other and at least one of which is formed of a piezoelectric material;
- at least one first electrode which is embedded in said at least one of the first sheet member and the second sheet member;
- at least one second electrode which is embedded in said at least one of the first sheet member and the second sheet member, such that said at least one second electrode is opposed to said at least one first electrode in a surface direction parallel to a first surface of the first sheet member and a second surface of the second sheet member that are apart from, and opposite to, each other in respective directions of thickness of the first and second sheet members;
- and
- a liquid-chamber defining member which cooperates with one of the first and second surfaces of the first and second sheet members to define a liquid chamber in which a liquid is accommodated,
- wherein an electric field is applied between said at least one first electrode and said at least one second electrode, so as to produce a difference between an amount of elongation in the surface direction of the first sheet member and an amount of elongation in the surface direction of the second sheet member and thereby curve the first and second sheet members in the respective directions of thickness thereof and change a pressure of the liquid accommodated in the liquid chamber.
3 more elements
Dependencies are inferred from the claim text.