# US 11,999,174 B2 · Enhanced speed thermal printer

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- Number: US 11,999,174 B2
- Document ID: US11999174B2
- Status: Granted
- Kind: B2
- Application number: 17/901,946
- Filed: 2022-09-02
- Published: 2023-03-02
- Granted: 2024-06-04
- Earliest claimed: 2021-09-02
- Assignees: Toshiba America Business Solutions, Inc.
- Applicants: Toshiba America Business Solutions, Inc.
- Inventors: William M. Connors; Donn D. Bryant; Michael W. Lawrence
- Web page: https://patentgrep.com/patent/US11999174B2

## CPC

- B41J 2/325: by selective transfer of ink from ink carrier, e.g. from ink ribbon or sheet
- B41J 2/315: characterised by selective application of heat to a heat sensitive printing or impression-transfer material (B41J2/385, B41J2/435 take precedence)
- B41J 11/02: Platens
- B41J 11/04: Roller platens
- B41J 11/14: Platen-shift mechanisms; Driving gear therefor
- B41J 11/20: Platen adjustments for varying the strength of impression, for a varying number of papers, for wear or for alignment {, or for print gap adjustment}
- B41J 29/38: Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A system and method for enhanced speed thermal printing has a drive roller for contacting thermochromic medal to a thermal printhead. The drive roller includes a cam which causes the drive roller to decelerate as it approaches the printhead such that contact with the thermal printhead and the thermochromic media is at a highest force point. The drive roller accelerates as it is pulled back from the printhead prior to a next printing cycle.

## Claims

### Claim 1

A system comprising:
first and second drive rollers configured to cooperatively move thermochromic media relative to a thermal printhead;
the thermal printhead configured to be positioned adjacent to but not in contact with a first side of the thermochromic media;
a biasing spring secured to the thermal printhead, the biasing spring configured to bias the thermal print head for perpendicular movement relative to the thermochromic media;
a backing roller disposed on a second side of the thermochromic media opposite the thermal printhead, the backing roller having an axis perpendicular to a feed direction of the thermochromic media;
the backing roller configured to be positioned adjacent to the second side of the thermochromic media;
the backing roller including an elliptical cam portion;
a drive shaft coupled to the elliptical cam portion, the drive shaft disposed radially relative to the axis of the backing roller; and
a motor configured to rotate the drive shaft wherein, when rotated the backing roller periodically causes the first side of the thermochromic media to contact the thermal printhead while compressing the biasing spring, and
periodically causes the first side of the thermochromic media to break contact with the thermal printhead.

### Claim 2 (depends on 1)

The system of claim 1 wherein an the elliptical cam portion has a major axis radially extending from the axis of the backing roller, and wherein a first side of the major axis is disposed radially outward from an opposed, second side of the major axis, and wherein the drive shaft is coupled to the first side of the major axis.

### Claim 3 (depends on 2)

The system of claim 2 wherein the biasing spring has a spring constant corresponding to a thermal printing printhead contact pressure.

### Claim 4 (depends on 3)

The system of claim 3 wherein a thermal printing contact pressure is in the range of 13 pounds to 19 pounds.

### Claim 5 (depends on 4)

The system of claim 4 wherein the elliptical cam portion is disposed on a side of the backing roller.

### Claim 6 (depends on 5)

The system of claim 5 further comprising third and fourth drive rollers configured to cooperatively move paper media relative to the thermal print head concurrently with the thermochromic media such that an image is formed on the paper media by contact between the thermochromic media and the paper media.

### Claim 7 (depends on 5)

The system of claim 5 wherein the backing roller accelerates then decelerates to contact the thermochromic media.

### Claim 8

A method comprising:
moving thermochromic media relative to a thermal print head via first and second drive rollers;
positioning the thermal printhead to be adjacent to but not in contact with a first side of the thermochromic media;
positioning a backing roller on a second side of the thermochromic media opposite the thermal printhead, the backing roller having an axis perpendicular to a feed direction of the thermochromic media; and
rotating a cam portion of the backing roller such that the backing roller, when rotated engages the second side of the thermochromic media so as to cause the first side of the thermochromic media to contact the thermal printhead while compressing a biasing spring associated with the thermal printhead,
periodically causes the first side of the thermochromic media to break contact with the thermal printhead.

### Claim 9 (depends on 8)

The method of claim 8 wherein an elliptical cam portion has a major axis radially extending from the axis of the backing roller, and wherein a first side of the major axis is disposed radially outward from an opposed, second side of the major axis, and wherein a drive shaft is coupled to the first side of the major axis.

### Claim 10 (depends on 9)

The method of claim 9 wherein the biasing spring has a spring constant corresponding to a thermal printing printhead contact pressure.

### Claim 11 (depends on 10)

The method of claim 10 wherein a thermal printing contact pressure is in the range of 13 pounds to 19 pounds.

### Claim 12 (depends on 11)

The method of claim 11 wherein the cam portion is disposed on a side of the backing roller.

### Claim 13 (depends on 12)

The method of claim 12 further comprising moving a paper media relative to the thermal print head concurrently with the thermochromic media such that an image is formed on the paper media by contact between the thermochromic media and the paper media.

### Claim 14 (depends on 12)

The method of claim 12 wherein the backing roller accelerates then decelerates to contact the thermochromic media.

### Claim 15

A method comprising:
positioning a print media such that a first side thereof is adjacent to but not in contact with a printhead;
accelerating a position of a backing roller disposed on a second side of the print media opposite the printhead toward the second side of the print media and the printhead;
decelerating the position of the backing roller toward the second side of the print media and the printhead and, after deceleration, the backing roller urging contact between the printhead and the first side of the print media and compression of a biasing spring associated with the printhead;
accelerating the position of the backing roller away from the print media and the printhead; and
decelerating the position of the backing roller away from the print media and the printhead.

### Claim 16 (depends on 15)

The method of claim 15 further comprising generating an image on the print media in accordance with contact between the printhead and the print media.

### Claim 17 (depends on 16)

The method of claim 16 a force potential between the printhead and the backing roller increases during deceleration and decreases during acceleration.

### Claim 18 (depends on 17)

The method of claim 17 further comprising selectively heating a surface of the printhead to generate the image.

### Claim 19 (depends on 18)

The method of claim 18 wherein the print media is thermochromic.

### Claim 20 (depends on 19)

The method of claim 19 further comprising periodically accelerating and decelerating the backing roller toward the print media and the printhead, and periodically accelerating and decelerating the backing roller away from the print media and the printhead.