Sales-registration-data processing apparatus

A sales-registration-data processing apparatus comprising:

• a housing for accommodating a control unit, the housing having an outer surface in which a recess having a semicircular cross section is provided;
• a display unit being independent of said housing and having front and back surfaces, a display portion being provided on the front surface of said display unit, and an expanding portion having a semicircular cross section being provided in the back surface of said display unit, and wherein the expanding portion is arranged in the recess of said housing so as to be movable along a curvature portion of the recess;
• and
• a tilt-angle adjustment and maintaining mechanism rotatably connecting said display unit to said housing, capable of tilting said display unit in the recess of said housing from a laid-down position in which the display portion of said display unit is laid down along the outer surface of said housing, to a desired tilt angle of said display unit relative to said housing, and maintaining a desired tilt angle of said display unit, wherein said tilt-angle adjustment and maintaining mechanism includes:
• at least one erection guide groove formed in the recess of said housing and having a substantially semicircular-arc shaped vertical cross section extending along the curvature of the recess;
• at least one guide projection mounted on the expanding portion of the back surface of said display unit and being slidable along said at least one erection guide groove of said housing;
• and
• a frictional-force adjustment mechanism mounted on said at least one guide projection so as to be frictionally engaged with said at least one erection guide groove and capable of adjusting a frictional force generated between said frictional-force adjustment mechanism and said at least one erection guide groove.