Near-end of roll detecting apparatus for detecting near-end of roll of recording medium, and printer

Patent metadata

Field	Value
Publication number	US-9505575-B2
Application number	US-76014310-A
Country	US
Kind code	B2
Filing date	Apr 14, 2010
Priority date	Jun 8, 2009
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

To improve precision in identifying the amount that remains of a recording medium, an apparatus includes a paper holder that supports an outer circumferential surface of a recording medium that is biased downward in a vertical direction by the weight of the recording medium, such that a position of a center of the recording medium moves on a straight-line trace, associated with consumption of the recording medium; and a light-reflecting sensor that is provided at a predetermined position at a side face of the paper holder and senses displacement per unit time at a position facing the predetermined position of the recording medium that is rotated by being pulled out of the paper holder, associated with the consumption of the recording medium, where based on the displacement sensed by the light-reflecting sensor, a radius of the recording medium at the time the light reflecting sensor senses the displacement is calculated.

First claim

What is claimed is:

1. A near-end of roll detecting apparatus for a roll of recording medium, comprising:
a recording medium support unit that supports an outer circumferential surface of the recording medium that is biased downward in a vertical direction by the weight of the recording medium, such that a position of a center of the recording medium moves on a straight-line trace, associated with consumption of the recording medium;
a displacement sensing unit that is provided at a position facing a predetermined position at a side face of the recording medium and senses displacement per unit time at the predetermined position at the side face of the recording medium when the recording medium is rotated by being pulled out of the recording medium support unit, associated with the consumption of the recording medium, wherein the rotational axis of the roll is perpendicular to the side face; and
a calculating unit that calculates based on the displacement sensed by the displacement sensing unit, a radius of the recording medium at the time the displacement sensing unit senses the displacement.

2. The near-end of roll detecting apparatus according to claim 1 , wherein
the calculating unit calculates a velocity of the recording medium at the position facing the predetermined position; calculates based on the calculated velocity, a distance between the position facing the predetermined position and the position of the center; identifies based on the calculated distance and a linear equation that expresses trace of the displacement of the position of the center in a plane that at a right angle, crosses a rotation axis of the recording medium, the position of the center in the plane; and calculates based on the identified position of the center, the radius of the recording medium at the time the displacement sensing unit senses the displacement.

3. The near-end of roll detecting apparatus according to claim 1 , further comprising a reporting unit that reports based on the radius of the recording medium calculated by the calculating unit, a remaining amount of the recording medium.

4. A printer comprising:
a printing unit that prints on the recording medium supplied from the recording medium support unit; and
the near-end of roll detecting apparatus according to claim 1 .

5. A printer comprising:
a printing unit that prints on the recording medium supplied from the recording medium support unit; and
the near-end of roll detecting apparatus according to claim 3 .

6. A printer comprising:
a printing unit that prints on the recording medium supplied from the recording medium support unit; and
the near-end of roll detecting apparatus according to claim 2 .

7. The near-end of roll detecting apparatus according to claim 2 , further comprising a reporting unit that reports based on the radius of the recording medium calculated by the calculating unit, a remaining amount of the recording medium.

8. A printer comprising:
a printing unit that prints on the recording medium supplied from the recording medium support unit; and

the near-end of roll detecting apparatus according to claim 7 .

Assignees

• Tsugaru Hiroyuki
• Matsushima Gen
• Mukaijima Katsutoshi
• Yamamoto Tetsuya
• Citizen Holdings Co Ltd
• Citizen Systems Japan Co Ltd

Inventors

• Tsugaru Hiroyuki
• Matsushima Gen
• Mukaijima Katsutoshi
• Yamamoto Tetsuya

Classifications

• B65H2220/03

  indicating an entity which is measured, estimated, evaluated, calculated or determined but which does not constitute an entity which is adjusted or changed by the control process per se · CPC title

• B65H2220/02

  indicating an entity which is controlled, adjusted or changed by a control process, i.e. output · CPC title

• B65H2511/142

  Operations & Transport · mapped topic

• B65H2801/12

  Single-function printing machines, typically table-top machines · CPC title

• B65H2301/41522

  Detecting residual amount of web · CPC title