Nec Display Solutions, Ltd.

Kenji Kanzaka

Hiroki Tanaka

Michio Kobayashi

Yukinori Shioya

A projection display apparatus includes: a display element that displays an image; a lamp that illuminates the display element to cause the display element to emit an image light; a variable light intensity element that allows the light emitted from the lamp to pass therethrough, the intensity of light passing through the variable light intensity element being variable; and a light intensity controller that determines whether the display element is at an image mute state in which a full-black image is displayed, or at a normal lighting state other than the image mute state, and when the display element is at the image mute state, reduces the amount of power supplied to the lamp to a level that is lower than that of the normal lighting state to decrease the intensity of light emitted from the lamp, and also decreases the intensity of light that passes through the variable light intensity element.

Projection display apparatus and control method therefor

In an electronic device including a discharge lamp, and a lamp power supply section that supplies power to the discharge lamp, a control section makes the lamp power supply section execute a lamp refresh process of supplying power necessary for generation of a halogen cycle to the discharge lamp at predetermined time intervals during low power operation in which the discharge lamp is lighted with power less than the rated power. Further, the control section records, in a recording section (non-volatile memory), a control instruction which is issued to the lamp power supply section during low power operation.

Electronic device and control method therefor

A projection display apparatus comprises a lamp; a display element that modulates light emitted from the lamp according to an amplitude of the image signal, and emits the light as the image light; a light intensity controller that changes a lamp power according to a power changing operation, and, if the changed lamp power is lower than a rated power of the lamp and supplied to the lamp for a certain period of time, increases the lamp power and then reduces the lamp power to an original power, identifies an amplitude of the image signal where an intensity of the image light is constant before and after the change of the lamp power; and an image signal controller that controls the amplitude of the image signal to the identified amplitude, and supplies the display element with the image signal.

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Tokyo, Japan

Kenji Kanzaka