Patent ID: 7339862
Filing Date: 2008-03-04
Classification: G11B,H04N

Abstract:
1. An optical disc driving system for reading out audio and/or video data recorded in an optical disc, said optical disc driving system comprising: an optical disc driving unit; and an external appliance, wherein said optical disc driving unit comprising: a disc spindle motor for rotating said optical disc at one of predetermined rotation speeds each having a discrete value; an optical pickup movable in the radial direction of said optical disc for reading out said data therefrom by detecting the light reflected from said optical disc which is irradiated by laser light; a memory for temporally storing data read out by said optical pickup; an input/output section for inputting said data from said external appliance to said optical drive unit and for outputting said data from said optical disc driving unit to said external appliance; a control unit for controlling said disc spindle motor, said optical pickup and said memory; and a control input section for inputting control signals from said external appliance into said control unit, wherein said external appliance comprising: at least one detector for measuring at least one parameter as for environmental conditions in the vicinity of said optical disc driving unit; a storage unit for storing predetermined upper and lower limits of the rotation speed for said optical disc within the range of said at least one parameter in at least one table; and process means for determining permissible upper and lower limits of the rotation speed by comparing the measured parameter with that in said at least one table and for supplying the upper and lower limits thus determined to said control unit, whereby said control unit determines the rotation speed at which said data can be actually read out, after stepwise decreasing the rotation speed from said upper limit to said lower limit, based on said upper and lower limits of the rotation speed supplied from said external appliance, and then supplies the rotation speed thus determined to said memory.