Paper feeder with separation pad and vibration buffers
A paper feeder is capable of minimizing abnormal noise produced at a separation pad during paper feed, without reducing the paper feed capability, for use in an image forming apparatus using the same. Buffers are mounted on the separation pad. This arrangement ensures that, when a stick-slip condition occurs between the paper and separation pad during paper feed, and the separation pad is vibrated by the paper, the buffer vibrates so as to dissipate the vibration energy of the separation pad, with the result that the vibration of the separation pad is minimized, thereby to reduce any abnormal noise.
1. A paper feeder comprising:
a paper feed roller for feeding paper;
a separation pad holder for supporting a separation pad rotatably about a shaft in parallel to a direction of paper feed and for applying said separation pad to said paper feed roller; and
a holder support for supporting said separation pad holder rotatably about a rotary shaft parallel to a tangential line of said separation pad and paper feed roller;
wherein sheets of paper are fed by separating them one by one and feeding them between said paper feed roller and said separation pad;
characterized in that said separation pad includes one or more vibration buffers provided on the separation pad at an outer right side and one or more vibration buffers provided at an outer left side in a paper feed direction each in the form of a cantilever beam, said vibration buffers being mounted as a pair extending in one direction of the separation pad, wherein one end of a viscoelastic body is secured to said separation pad, and wherein the other end of the viscoelastic body does not contact any portion of the paper feeder or separation pad.
2. The paper feeder described in claim 1 , characterized in that a value obtained by dividing a logarithmic decrement of said vibration buffer in a case where a free end is measured by a primary resonant frequency of said vibration buffer in the case where the free end is measured is equal to or greater than 2.0×10 −2 (1/Hz).
3. The paper feeder described in claim 1 , characterized in that said viscoelastic body of said vibration buffer is cylindrical.
4. The paper feeder described in claim 1 , characterized in that said viscoelastic body of said vibration buffer is made of rubber.
5. The paper feeder described in claim 1 , characterized in that said viscoelastic body of said vibration buffer is formed of a spring or a member having a surface of a spring coated with a viscoelastic material.
6. The paper feeder described in claim 1 , characterized in that said viscoelastic body is bonded to a fixture with an adhesive.
7. The paper feeder described in claim 1 , characterized in that said vibration buffer consists of said viscoelastic body and a fixture crimping about said viscoelastic body.
8. The paper feeder described in claim 1 , characterized in that the paper feeder forms a part of an image forming apparatus.
9. The paper feeder described in claim 1 , characterized in that the paper feeder is adapted to be connected to an image forming apparatus so as to feed paper thereto.