US Patent No. 9,852,680

PROJECTION TYPE DISPLAY DEVICE AND METHOD FOR CONTROLLING OPERATION OF PROJECTION TYPE DISPLAY DEVICE


Patent No. 9,852,680
Issue Date December 26, 2017
Title Projection Type Display Device And Method For Controlling Operation Of Projection Type Display Device
Inventorship Hiroshi Kato, Tokyo (JP)
Assignee NEC DISPLAY SOLUTIONS, LTD., Tokyo (JP)

Claim of US Patent No. 9,852,680

1. A projection-type display device that projects and displays images in accordance with an image signal, comprising:
a light source for projecting the images;
an output unit that is equipped with a coil and switch, that uses electromagnetic induction of the coil to supply a current,
and that changes the magnitude of the current by means of the switch;

a cooling fan that cools a component within the projection-type display device and for which the rotational speed is variable;
and

a control unit including a memory unit and a regulator storing instructions to cause the control unit to:
upon receiving an instruction to set a first mode, concurrently both controls the switch to set the output current of the
output unit to a first current and intermittently supply the first current to the light source in accordance with a Pulse-Width
Modulation (PWM) signal and sets the rotational speed of the cooling fan to a first rotational speed; and

upon receiving an instruction to set a second mode in which the light source continuously emits light for projecting the images,
concurrently both controls the switch to set the output current of the output unit to a second current that is smaller than
the first current and continuously supply the second current to the light source and sets the rotational speed of the cooling
fan to a second rotational speed that is lower than the first rotational speed,

wherein, in the second mode, the regulator sets a state in which the LED lighting duty equals 100%.