Patent attributes
A writing current circuit (42) supplies a controlled electrical current to a laser diode (34) for recording data swiftly onto a DVD (16). A plurality of current sources (62) in the writing current circuit (42) supply electrical current to the laser diode (34). Each current source (62) respectively receives a single output signal from a current control register (52) included in the writing current circuit (42) which activates or deactivates the current source (62) for supplying a particular quantity of electrical current to the laser diode (34). In each current source (62), electrical current flows to the laser diode (34) through a MOSFET output transistor (142) connected in series with the laser diode (34). Each current source's MOSFET output transistor (142) has 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 the it applied to the writing current circuit (42).
