Thermal ink jet printer

Claim 2

A printer (10), which forms an image on a sheet by ejecting ink onto the sheet in accordance with an image signal, having a thermal head (106) having heating elements (104) heated in accordance with the image signal, a recording medium (108) in which a plurality of holes (109) to be filled with ink are formed, and which generates bubbles from the holes when ink is heated and ejects the ink due to pressure from the bubbles, feeding means (198) for feeding said recording medium between said heating elements of said thermal head and the sheet, and sheet conveying means for conveying the sheet (14) to a position facing said heating elements (104) through said recording medium, characterized in that said feeding means feeds said recording medium at a speed lower than a sheet conveying speed.

Claim 3

A printer according to claim 1, characterized in that said feeding means feeds said recording medium (108) lower than a half speed of a sheet moving speed.

Claim 4

A printer (10), which forms an image on a sheet by ejecting ink onto the sheet in accordance with an image signal, having a thermal head (106) having heating elements (104) heated in accordance with the image signal, a recording medium (108) in which a plurality of holes (109) to be filled with ink are formed, and which generates bubbles from the holes when ink is heated and ejects the ink due to pressure from the bubbles, feeding means (198) for feeding said recording medium to said heating elements, and sheet conveying means for conveying the sheet (14) to a position facing said heating elements (104) of said thermal head (106) through said recording medium, characterized in that said feeding means (198) selectively drives said recording medium (108) in a first feed mode in which said recording medium is fed in the same direction as that of the conveying direction of the sheet and in a second feed mode in which said recording medium is fed in a direction opposite to the conveying direction of the sheet.

Claim 5

A printer (10), which forms an image on a sheet by ejecting ink onto the sheet in accordance with an image signal, having a thermal head (106) having heating elements (104) heated in accordance with the image signal, a recording medium (108) in which a plurality of holes (109) to be filled with ink are formed, and which generates bubbles from the holes when ink is heated and ejects the ink due to pressure from the bubbles, feeding means (198) for feeding said recording medium to said heating elements, and sheet conveying means for conveying the sheet (14) to a position facing said heating elements (104) of said thermal head (106) through said recording medium, characterized in that said feeding means (198) selectively drives said recording medium (108) in a first feed mode in which said recording medium is fed in the same direction as that of the conveying direction of the sheet and in a second feed mode in which said recording medium is fed in a direction opposite to the conveying direction of the sheet.

Claim 6

A printer according to claim 3, characterized in that said feeding means (198) alternately executes the first and second feed modes.

Claim 7

A printer according to claim 3, characterized in that said feeding means (198) feeds said recording medium in the first feed mode during the printing operation.

Claim 8

A printer according to claim 3, characterized in that said feeding means (198) takes a given interval between the first and second feed modes.

Claim 9

A printer according to claim 1, characterized in that said feeding means (198) has a detector for detecting front and distal end portions of the sheet, and switches the first and second feed modes in a time interval from when said detector detects the rear end portion of a sheet until it detects the front end portion of a subsequent sheet.

Claim 10

A printer according to claim 1, characterized in that said feeding means (198) executes at least one of the first and second feed modes for a predetermined period of time before the printing operation starts.

Claim 11

A printer according to claim 1, characterized in that said feeding means (198) executes at least one of the first and second feed modes for a predetermined period of time after the printing operation is completed.

Claim 12

A printer according to claim 9, characterized in that said feeding means (198) sets a moving speed of said recording medium after the printing operation is completed to be lower than that during the printing operation.

Claim 13

A printer (10), which forms an image on a sheet (14) by ejecting ink onto the sheet in accordance with an image signal, having a thermal head (106) having heating elements (104) heated in accordance with the image signal, a recording medium - (108) in which a plurality of holes (109) to be filled with ink are formed, and which generates bubbles from the holes when ink is heated and ejects the ink due to a pressure of the bubbles, feeding means (198) for feeding said recording medium between said heating elements of said thermal head and the sheet, and sheet conveying means (198) for conveying the sheet (14) to a position facing said heating elements (104) of said thermal head (106) through said recording medium, characterized in that said feeding means (198) has detecting means (250) for detecting an initial position of said recording medium in its moving direction to produce a detection signal, so that the front end of the sheet is aligned with the initial position of said recording medium in accordance with the detection signal.

Claim 14

A printer (10), which forms an image on a sheet (14) by ejecting ink onto the sheet in accordance with an image signal, having a thermal head (106) having heating elements (104) heated in accordance with the image signal, a recording medium - (108) in which a plurality of holes (109) to be filled with ink are formed, and which generates bubbles from the holes when ink is heated and ejects the ink due to a pressure of the bubbles, feeding means (198) for feeding said recording medium between said heating elements of said thermal head and the sheet, and sheet conveying means (198) for conveying the sheet (14) to a position facing said heating elements (104) of said thermal head (106) through said recording medium, characterized in that said feeding means (198) has detecting means (250) for detecting an initial position of said recording medium in its moving direction to produce a detection signal, so that the front end of the sheet is aligned with the initial position of said recording medium in accordance with the detection signal.

Claim 15

A printer according to claim 8, characterized in that said feeding means (198) has rolls (204, 206) for winding said recording medium therearound, and further has a disk (244) which is rotated together with said rolls and in a portion of which slits (246, 248) are formed, and a detector (250) for detecting these slits (246, 248).