Patent ID: 8976827
Filing Date: 2015-03-10
Classification: H01S

Abstract:
1. A driving device, comprising: a driving circuit configured to provide a drive current depending on a magnitude of a control voltage to a light-emitting element; a first detecting circuit configured to detect the drive current or a physical quantity corresponding thereto; a second detecting circuit configured to detect a first reference current to be used as a reference for a drive current at a light-emission time of the light-emitting element or a physical quantity corresponding thereto, as well as a second reference current to be used as a reference for a drive current at a non-light-emission time of the light-emitting element or a physical quantity corresponding thereto; a first generating circuit configured to generate an additive voltage obtained by adding a first voltage and a correction voltage with each other as a control voltage at the light-emission time of the light-emitting element, and further to generate a second voltage that is derived according to a result of comparing a detection result from the first detecting circuit at the non-light-emission time of the light-emitting element and a detection result from the second detecting circuit at the non-light-emission time of the light-emitting element as a control voltage at the non-light-emission time of the light-emitting element, the first voltage being derived according to a result of comparing a detection result from the first detecting circuit at the light-emission time of the light-emitting element and a detection result from the second detecting circuit at the light-emission time of the light-emitting element, the correction voltage being derived by a predetermined calculation; and a second generating circuit configured to generate a third reference current that is equivalent to a difference between the first reference current and the second reference current by using the control voltage at the light-emission time of the light-emitting element, the first voltage, the second voltage, and the second reference current, wherein the second detecting circuit has a first adder circuit that generates the first reference current by adding the second reference current and the third reference current with each other.