Mechanism for preventing a winding slack of a roll paper

1. A roll paper winding slack preventing mechanism,

wherein a first rotation support member, a second rotation support member, and an inclined surface are provided in a housing,

said second rotation support member is disposed in said housing so as to be rotatable on its own axis and movable in a horizontal direction,

a position of said first rotation support member is set higher than that of said second rotation support member and the position of said second rotation support member is set lower than that of said inclined surface,

when a roll paper is held in said housing with no winding slack, a wound portion of said roll paper is supported by said first rotation support member and said second rotation support member, and said first rotation support member and said second rotation support member rotate in one direction, respectively, and

when said wound portion of the roll paper is displaced due to vibration or impact, said wound portion of the roll paper rides on said inclined surface and then slides down said inclined surface to push said second rotation support member so that said second rotation support member rotates in a direction opposite to said one direction and moves in the horizontal direction, while said wound portion of the roll paper rotates in a direction to eliminate winding slack of said roll paper.

2. The roll paper winding slack preventing mechanism according to claim 1 , wherein said first rotation support member is a roller.

3. The roll paper winding slack preventing mechanism according to claim 1 , wherein said second rotation support member is a cylindrical shaft.

4. The roll paper winding slack preventing mechanism according to claim 1 , wherein said second rotation support member is disposed so as to be rotatable on its own axis and movable in the horizontal direction in a generally rectangular hole formed in said housing or a separate member.

5. The roll paper winding slack preventing mechanism according to claim 1 , wherein said inclined surface is formed in said housing or using a separate member.

6. A printer comprising the roll paper winding slack preventing mechanism according to claim 1 .

7. A mechanism for handling a roll paper, comprising:

a receiving area for receiving the roll paper to have a horizontal rolling axis;

an inclined surface which faces the receiving area in the vicinity of a lowest part of the receiving area; and

a rotation making member which faces the receiving area at a position being lower than the inclined surface;

wherein the inclined surface makes the roll paper be slid towards the lowest part of the receiving area when the inclined surface receives the roll paper that is out of the receiving area;

wherein the rotation making member rotates the roll paper around the horizontal rolling axis towards a winding direction of the roll paper in response to movement of the roll paper towards the lowest part of the receiving area; and

wherein the rotation making member comprises a movable shaft which is movable in a horizontal direction perpendicular to the horizontal rolling axis, and the movable shaft rotates in accordance with movement thereof to rotate the roll paper towards the winding direction.

8. The mechanism according to claim 7 , further comprising a housing which defines the receiving area and having an edge defining a hole receiving the movable shaft therein, wherein the movable shaft frictionally engages with the age so as to rotate in response to movement along the edge.

9. The mechanism according to claim 8 , wherein the hole restricts a movable range of the movable shaft in the horizontal direction.

10. The mechanism according to claim 7 , further comprising a support member which faces the receiving area at a position being higher than the rotation making member, wherein the rotation making member is placed between the inclined surface and the supporting member.

11. The mechanism according to claim 10 , wherein the support member and the rotation making member are apart from to each other and cooperated with to each other to maintain the roll paper in the receiving area.