Control device, optical scanning device, display apparatus, and control method

A control device for a laser scanning display apparatus, the control device comprising:

• a laser device;
• a current source that generates an electric current supplied to the laser device;
• and
• a controller that controls the current source to set a current value of the electric current supplied to the laser device, wherein
• during a period for scanning a non-display area where no image is displayed, the controller sets the current value at a first drive current value that is greater than zero and less than a threshold current value at which the laser device starts oscillating;
• during a period for scanning a portion with a luminance level of zero in a display area where an image is displayed, the controller sets the current value at a second drive current value that is greater than or equal to the first drive current value and less than the threshold current value;
• the current source includes a first current source and a second current source;
• the controller sets an electric current generated by the first current source at a first set current value that is “threshold current value×1/n (n is a number greater than one)” and sets an electric current generated by the second current source at a second set current value that is greater than the first set current value and less than “threshold current value×(1−1/n)”;
• and
• the first drive current value is the first set current value, and the second drive current value is a sum of the first set current value and the second set current value.