Thermal printer

Claim 2

A thermal printer for image recording on a recording sheet by transferring ink from an ink sheet, comprising: a head comprising a first heating element group including an array of selectively drivable plural heating elements for heating the ink sheet to transfer ink to the recording sheet and a second heating element group including an array of selectively drivable plural heating elements for heating the ink sheet to transfer ink to the recording sheet; moving means for effecting relative movement of the recording sheet and said head; actuating means for alternatively actuating said first and second heating element groups as said head and the recording sheet move relative to each other to record the image on the recording sheet in accordance with the particular said heating elements being driven in each said group; and control means for controlling the amount of heat generated by said heating elements of said first heating element group and said second heating element group in accordance with predetermined control information indicative of the amount of heat accumulated in the ink sheet, so that the density of the recorded image is substantially uniform.

Claim 3

A thermal printer according to claim 1, wherein said first and second heating element groups are mutually parallel and are perpendicular to the direction of relative movement of the recording sheet and said head.

Claim 4

A thermal printer according to claim 1, wherein said control means is adapted to control the drive periods of said first and second heating element groups according to the amount of heat accumulated in said ink sheet.

Claim 5

A thermal printer according to claim 1, wherein said control means is adapted to control the drive voltage for said first and second heating element groups according to the amount of heat accumulated in said ink sheet.

Claim 6

A thermal printer according to claim 1, wherein said heating element groups are positioned along the direction of relative movement of the recording sheet and said head and said control means is adapted to reduce the drive period for said group positioned upstream in such direction in comparison with the drive period for the other said group.

Claim 7

A thermal printer according to claim 1, wherein said heating element groups are positioned along the direction of relative movement of the recording sheet and said head and said control means is adapted to reduce the driving voltage for said group positioned upstream in such direction in comparison with the driving voltage for the other said group.

Claim 8

A thermal printer for image recording on a recording sheet by transferring ink from an ink sheet, comprising: a head comprising a first heating element group including an array of selectively drivable plural heating elements for heating the ink sheet to transfer ink to the recording sheet and a second heating element group including an array of selectively drivable plural heating elements for heating the ink sheet to transfer ink to the recording sheet; moving means for effecting relative movement of the recording sheet and said head; and actuating means for alternately actuating said first and second heating elements groups as said head and the recording sheet move relative to each other to record the image on the recording sheet in accordance with the particular said heating elements being driven in each group; wherein said heating elements groups are positioned along the direction of relative movement of the recording sheet and said head, and said group positioned upstream in such direction includes heating elements having a predetermined larger resistance than that of said heating elements of said other heating element group in consideration of the amount of heat accumulated in the ink sheet so that the density of the recorded image is substantially uniform.

Claim 9

A thermal printer for image recording on a recording sheet by transferring ink from an ink sheet, comprising: a head comprising a first heating element group including an array of selectively drivable plural heating elements for heating the ink sheet to transfer ink to the recording sheet and a second heating element group including an array of selectively drivable plural heating elements for heating the ink sheet to transfer ink to the recording sheet; moving means for effecting relative movement of the recording sheet and said head; and actuating means for alternately actuating said first and second heating elements groups as said head and the recording sheet move relative to each other to record the image on the recording sheet in accordance with the particular said heating elements being driven in each group; wherein said heating elements groups are positioned along the direction of relative movement of the recording sheet and said head, and said group positioned upstream in such direction includes heating elements having a predetermined larger resistance than that of said heating elements of said other heating element group in consideration of the amount of heat accumulated in the ink sheet so that the density of the recorded image is substantially uniform.

Claim 10

A thermal printer according to claim 1, wherein a character is printed by the cooperation of said first and second heating element groups.

Claim 11

A thermal printer according to claim 7, wherein a character is printed by the cooperation of said first and second heating element groups.

Claim 12

A thermal printer according to claim 1, wherein said heating elements of said first heating element group are arranged in corresponding relation with said heating elements of said second heating element group.

Claim 13

A thermal printer according to claim 1, wherein said head is moved in across the width recording sheet.

Claim 14

A thermal printer according to claim 1, wherein the ink sheet is removably mounted on a mount portion provided on the printer.

Claim 15

A thermal printer according to claim 1, wherein the control information indicates whether the preceding array of heating elements were heated.

Claim 16

A thermal printer according to claim 7, wherein said heating elements of said first heating element group are arranged in corresponding relation with said heating elements of said second heating element group.

Claim 17

A thermal printer according to claim 7, wherein said head is moved across the width of the recording sheet.

Claim 18

A thermal printer according to claim 7, wherein the ink sheet is removably mounted on a mount portion provided on the printer.

Claim 19

A thermal printer for image recording on a recording sheet by transferring ink from an ink sheet, comprising: a head having (i) a first printing element array including a plurality of printing elements, arranged transversely of a recording direction at a predetermined interval, for heating the ink sheet to transfer ink to the recording sheet, and (ii) a second printing element array including a plurality of printing elements, arranged in corresponding relation to said respective printing elements of said first printing element array, for heating the ink sheet to transfer ink to the recording sheet; moving means for effecting relative movement between the recording sheet and said head; actuating means for alternately actuating said first and second printing element arrays as said head and the recording sheet move relative to each other to record the image on the recording sheet in accordance with the particular said printing elements being driven in each said array; and control means for controlling the amount of heat generated by said printing elements of said first and second printing element arrays in accordance with predetermined control information indicative of the amount of heat accumulated in the ink sheet, so that the density of the recorded image is substantially uniform.

Claim 20

A thermal printer for image recording on a recording sheet by transferring ink from an ink sheet, comprising: a head having (i) a first printing element array including a plurality of printing elements, arranged transversely of a recording direction at a predetermined interval, for heating the ink sheet to transfer ink to the recording sheet, and (ii) a second printing element array including a plurality of printing elements, arranged in corresponding relation to said respective printing elements of said first printing element array, for heating the ink sheet to transfer ink to the recording sheet; moving means for effecting relative movement between the recording sheet and said head; actuating means for alternately actuating said first and second printing element arrays as said head and the recording sheet move relative to each other to record the image on the recording sheet in accordance with the particular said printing elements being driven in each said array; and control means for controlling the amount of heat generated by said printing elements of said first and second printing element arrays in accordance with predetermined control information indicative of the amount of heat accumulated in the ink sheet, so that the density of the recorded image is substantially uniform.