Recording head and recording apparatus and method of manufacturing same
AssigneeCanon Kabushiki Kaisha
InventorTetsuo Asaba
Life of this patent
Estimating the term…
Abstract
The occupied area of a heater drive circuit of a recording head is reduced, and the number of manufacturing steps is decreased. As a circuitry of the heater drive unit, the final stage of the drive unit is constituted of a pnp or npn bipolar transistor, the heater, which is a load, is connected to the emitter side, and the collectors of each transistor are connected commonly to the base itself and grounded. The prestage of the drive unit is formed of the prestage of a MOS type element whose polarities are reversed to those of the final stage, i.e., an n-type MOS transistor with respect to the final stage of a pnp bipolar transistor and a p-type MOS transistor with respect to the final stage of a npn bipolar transistor, and the source of the prestage is grounded.
Claims33
An inkjet recording head, comprising:
- a heat generating member having at least two terminals;
- and
- a drive circuit for supplying an electric current to said heat generating member, wherein said drive circuit comprises;
- a bipolar transistor having a plurality of main electrode regions and a control electrode region, one of the main electrode regions being connected to one of the terminals of said heat generating member, and
- a field-effect transistor having a plurality of main electrode regions and having one of the main electrode regions connected to the control electrode region of said bipolar transistor, and wherein a first voltage source is connected to the other terminal of said heat generating member, a second voltage source is connected to the other main electrode region of said bipolar transistor and the other main electrode region of said field-effect transistor,
- wherein said bipolar transistor is a pnp transistor, said field-effect transistor is an N-channel insulation gate type transistor, and said transistors are integrated in a p-type semiconductor substrate,
- wherein said bipolar transistor and said field-effect transistor are formed in each of two active regions surrounded by an insulating film region,
- wherein said one of the main electrode regions of said field-effect transistors includes a first region having an impurity concentration and a second region having an impurity concentration which is lower than that of said first region.
A method of manufacturing an ink jet recording head, comprising the steps of:
- providing an ink jet recording head comprising:
- a heater array comprising a plurality of heaters for heating an ink in order to generate gas bubbles and thereby eject the ink,
- a plurality of drive units for driving respective said heaters, each of said drive units comprising a field-effect transistor having a drain, at a prestage and a bipolar transistor having an emitter at a final stage, a collector and a base, at a final stage, and
- a logic circuit part in a same substrate as said heaters and said drive units, wherein each of said heaters is connected to the emitter of an associated said bipolar transistor, the respective collectors of said plurality of bipolar transistors are commonly connected and grounded, and the respective bases of said plurality of bipolar transistors are connected to the respective drains of said field-effect transistors, said logic circuit part comprising a complimentary field-effect transistor;
- and
- forming in a same step a low concentration diffusion layer from among two types of diffusion layers of said field-effect transistor at the prestage and a base region diffusion layer of the bipolar transistor at the final stage.
Dependencies are inferred from the claim text.