Patent ID: 7916613

Claim:
A writing current circuit ( 42 ) adapted for supplying a controlled electrical current to a laser diode ( 34 ) included in a drive ( 10 ) that is adapted for swiftly recording a Digital Video Disc (“DVD”) ( 16 ), the writing current circuit ( 42 ) operating responsive both: a. to write control digital data for controlling operation of the writing current circuit ( 42 ), the write control digital data including data which specifies an amount of electrical current which the writing current circuit ( 42 ) controllably supplies to the laser diode ( 34 ); and b. to serial digital data which controls application of the electrical current to the laser diode ( 34 ) thereby specifying digital data to be recorded on the DVD ( 16 ), both the write control digital data and the serial digital data being received from a control processor ( 14 ) included in the drive ( 10 ), operation of the writing current circuit ( 42 ) being energized by an electrical potential applied thereto, the writing current circuit ( 42 ) comprising: a plurality of separate current sources ( 62 ) each of which respectively receives a single output signal from a current control register ( 58 ) included in the writing current circuit ( 42 ), the output signal respectively received by each of the current sources ( 62 ) from the current control register ( 58 ): a. when in a first state activating the receiving current source ( 62 ) for supplying through a MOSFET output transistor ( 142 ) a particular quantity of electrical current to the laser diode ( 34 ) that connects via a current output line ( 48 ) in series with the MOSFET output transistor ( 142 ); and b. when in a second state deactivating the receiving current sources ( 62 ) for supplying through the MOSFET output transistor ( 142 ) the particular quantity of electrical current to the laser diode ( 34 ) via the current output line ( 48 ), the MOSFET output transistor ( 142 ) included in each of the current sources ( 62 ) having a gate insulating layer which is thinner than the gate insulating layer conventionally used for a MOSFET output transistor ( 142 ) that is energized by the electrical potential applied to the writing current circuit ( 42 ).