Apparatus and method for employing a host mode setting command to turn-off or leave-on a laser in an optical disk drive

An optical disk drive for exchanging data signals with an optical disk mounted for rotation at a play position in the optical disk drive, rotation means in the optical disk drive for rotating the optical disk, a laser in the optical disk drive that can be turned on to shine a light beam directed to impinge on an recording surface of the optical disk and that can be turn off, said optical disk drive having attachment means for connecting to an external host processor for receiving host-processor issued commands that command the optical disk drive to write data on and read data from a disk in the play position and to control the laser, means connected to the optical disk for continuously rotating the disk at said play position, a laser on-off control connected to the laser for turning the laser on and off;

• the improvement including, in combination:
• receiving means connected to the attachment means for receiving said host-processor issued commands to actuate the optical disk drive for writing data on and reading data from the optical disk;
• command execution means in the optical disk drive connected to the command receiving means for responding to each of the received host-processor issued commands for actuating the drive to execute the received host-processor issued command, said command execution means having means for indicating completion of each execution of each said host-processor issued command;
• mode control means connected to said laser on-off control and to said command execution means for receiving a mode setting command that indicates leaving said laser continuously on or turning said laser off after completing an execution of any subsequently received commands from said host-processor then turning said laser on upon receipt of a read or write command, said mode control means storing an indication of whether said laser is to be left on continuously or turned off after completing execution of said any subsequent command, said mode control means initially setting a mode indication to leave the laser on continuously and being responsive to said mode setting command indicating turn off the laser set said mode indication to indicate turn off the laser after completing a received host processor command;
• means in the command execution means and connected to the mode control means, to the receiving means and to said laser on-off control for responding to said indication of completion of each execution of each said received host-processor issued command for examining said mode indication for responding to the mode indication indicating turn off the laser for actuating the laser on-off control to turn the laser off while said rotation means continues to rotate the optical disk.