Cassette holder opening system having a damper

A cassette holder opening system comprising:

• a cassette holder for receiving a cassette tape;
• a frame for rotatably supporting the cassette holder, the frame having a sector gear formed at a part thereof, the cassette holder being hingedly attached to the frame by a pivot pin;
• a spring member disposed between the cassette holder and the frame to connect them with each other so as to provide spring force for opening the cassette holder;
• and
• a damper for damping the spring force to open the cassette holder, the damping force of which varies according to the open angle of the cassette holder, the damper including a shaft fixed on the cassette holder and having a screw formed on an outer surface of the shaft, a friction member disposed coaxially with the shaft to be in contact with the cassette holder, and a rolling member so fitted on the shaft as to be guided along the screw of the shaft,
• the rolling member having a body, a plurality of protrusions formed at one side of the body to be in slidable contact with the friction member, and a rolling gear formed at the other side of the body to be engaged with the sector gear,
• wherein the rolling gear rolls along the sector gear, and thereby the rolling member is guided along the screw of the shaft, so that a distance between the friction member and the rolling member and accordingly the frictional force therebetween are changed, when the cassette holder is pivoted about the pivot pin.