US Patent 7967450 Light amount control device and projector

A light amount control device that controls an amount of light acquired from a light source provided in an image display apparatus includes: a pulse generator; an operation processing portion for light amount control that outputs a transfer start signal at timing when the amount of light is controlled; a data setting circuit that is provided outside the operation processing portion and that stores data, in which various kinds of signals instructing the operation processing portion to set transfer data beforehand are set, in a memory; an address generator that is provided outside the operation processing portion and that sets an address in response to the transfer start signal output from the operation processing portion; a memory that is a main component included in the pulse generator and that outputs data on the basis of a memory address generated by the address generator; a pulse driven body whose operation direction and speed are determined by a pulse signal formed by data output from the memory and which is driven by a pulse; an actuator connected to the pulse driven body; and an opening capable of adjusting the amount of transmitted light according to an operation of the actuator inserted in an emission path of the light source.