Tape cassette having front and inner pivotal lids

A tape cassette comprising:

• a pair of tape reels for winding a tape thereon and for respectively fixedly holding leading and trailing ends of said tape, each of said tape reels having a rotational axis;
• a cassette case having a front, a back, and opposing side surfaces, and containing said pair of tape reels therein with a forwardly exposed portion of the tape being extended across said front of said cassette case, an opening being provided in said cassette case behind said forwardly exposed portion of the tape;
• first and second side walls arranged in the cassette case and having first and second surfaces, respectively, defining therebetween said opening;
• a front lid pivotably supported on said side surfaces of said cassette case for pivotal movement between a closed position in which said front lid covers a front surface of said forwardly exposed portion of the tape and an open position in which said front lid does not cover said forwardly exposed portion of the tape;
• an inner lid pivotably supported by first and second pivot shafts on said front lid for pivotal movement between a closed position in which said inner lid covers a back surface of said forwardly exposed portion of the tape when said front lid is in its closed position, and an open position in which said inner lid does not cover the back front surface of said forwardly exposed portion of the tape when said front lid is in its open position;
• wherein first and second guiding grooves are provided in said first and second side walls, respectively, for restricting said pivotal movement of said inner lid;
• wherein said first guiding groove has a first shape, said second guiding groove has a second shape, and said first and second shapes are different with respect to one another;
• wherein first and second guide projections are fixed integrally with said inner lid and are movably engaged in said first and second guiding grooves, respectively, for movement therealong;
• and
• wherein a positional relation of said first guide projection with respect to said first pivot shaft is different than a positional relation of said second guide projection with respect to said second pivot shaft.