Inkjet printer and inkjet printing method

A printing method used in an inkjet printer comprising steps of:

• discharging ink drops having large diameter in accordance with image data;
• discharging ink drops having small diameter in accordance with image data;
• wherein said ink drops having large diameter and said ink drops having small diameter have substantially the same color;
• and
• wherein a physical property of the ink drops having large diameter is different from a physical property of the ink drops having small diameter, said physical characteristic including at least one of viscosity and surface tension.

An ink-jet recording head for use in an ink-jet printer, comprising:

• a plurality of head portions, each of said head portions including an ink cavity for receiving an ink material, a piezoelectric member for pressurizing said ink material in said ink cavity, and a nozzle through which said pressurized ink material is ejected;
• wherein said ink material in each of said ink cavities has substantially the same color, and wherein said ink material in one of said plurality of ink cavities has a physical characteristic different than a physical characteristic of said ink material in another one of said plurality of ink cavities, said physical characteristic including at least one of viscosity and surface tension;
• and
• a drive circuit to apply a voltage to a selected one of the piezoelectric members to discharge an ink drop from a corresponding one of said nozzles;
• wherein as a result of said physical characteristic difference between said ink material in said one of said plurality of ink cavities and said ink material in said another one of said plurality of ink cavities, a size of an ink drop discharged from a nozzle corresponding to said one of said plurality of ink cavities and a size of an ink drop discharged from a nozzle corresponding to said another one of said plurality of ink cavities are different.

An ink-jet recording head for use in an ink-jet printer, comprising:

• a plurality of head portions, each of said head portions including an ink cavity for receiving an ink material, a piezoelectric member for pressurizing said ink material in said ink cavity, and a nozzle through which said pressurized ink material is ejected;
• wherein said ink material in each of said ink cavities has substantially the same color, and wherein said ink material in one of said plurality of ink cavities has a physical characteristic different than a physical characteristic of said ink material in another one of said plurality of ink cavities, said physical characteristic including at least one of viscosity and surface tension;
• and
• a drive circuit to apply a voltage to a selected one of the piezoelectric members to discharge an ink drop from a corresponding one of said nozzles, said applied voltage having a variable amplitude so that a size of said ink drop discharged can be controlled thereby;
• wherein as a result of said physical characteristic difference between said ink material in said one of said plurality of ink cavities and said ink material in said another one of said plurality of ink cavities, a first range of sizes of ink drops can be discharged from a nozzle corresponding to said one of said plurality of ink cavities and a second range of sizes of ink drops can be discharged from a nozzle corresponding to said another one of said plurality of ink cavities, said first range of sizes being different than said second range of sizes.

A method of printing with an ink-jet recording head in an ink-jet printer, comprising the steps of:

• providing a first ink material;
• providing a second ink material, said first and second ink materials having substantially the same color, said first ink material having a physical characteristic different than a physical characteristic of said second ink material, said physical characteristic including at least one of viscosity and surface tension;
• ejecting a first ink drop of said first ink material through a first nozzle by applying a first discharge force to a first ink cavity;
• ejecting a second ink drop of said second ink material through a second nozzle by applying a second discharge force to a second ink cavity;
• wherein as a result of said physical characteristic difference between said first ink material and said second ink material said first ink drop and said second ink drop have different sizes.

An ink-jet recording head for use in an ink-jet printer, comprising:

• an ink cavity for receiving an ink material from an ink reservoir, said ink material having a physical characteristic including at least one of viscosity and surface tension;
• a piezoelectric member for pressurizing said ink material in said ink cavity;
• a nozzle through which said pressurized ink material is ejected;
• a device for selectively modifying said physical characteristic of said ink material received in said ink cavity;
• and
• a drive circuit to apply a voltage to said piezoelectric member to discharge an ink drop having a selectively modified physical characteristic from said nozzle;
• wherein a size of ink drop discharged as a result of said applied voltage varies with said selective modification of said physical characteristic.

A method of printing with an ink-jet recording head comprising the steps of:

• receiving an ink material from an ink reservoir into an ink cavity, said ink material as received from said ink reservoir having a physical characteristic including at least one of viscosity and surface tension;
• pressurizing said ink material;
• selectively modifying said physical characteristic of said ink in said ink cavity so that said physical characteristic of said ink as modified is different than said physical characteristic of said ink material as received from said ink reservoir;
• discharging said ink material through a nozzle;
• wherein a size of ink drop discharged as a result of said step of pressuring said ink material varies with said selective modification of said physical characteristic.