JPH0472234U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a circuit block diagram showing one embodiment of the present invention, Fig. 2 is an explanatory diagram of the optical system of a liquid crystal projector, and Fig. 3 shows the operation of the embodiment shown in the circuit block diagram of Fig. 1. It is a flowchart figure for explaining. 3...High pressure discharge lamp, 11...Light source power supply circuit,
13...Power switch, 14...Operation switch group, 15...System control circuit, 16...Timer counter, 17...Character signal generation circuit, 18...Video processing circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A power supply circuit for a light source is powered by a power-on operation, a high-pressure discharge lamp for a projection light source is driven to be lit by the output of the power supply circuit, and a power-off operation is performed to drive a high-pressure discharge lamp for a projection light source. In the projection light source device that stops power supply to the power supply circuit, turns off the output of the power supply circuit, and turns off the discharge lamp, the timer counter is activated by the power-off operation and operates for a preset predetermined time. Equipped with
The projection light source device is configured to stop supplying power to the power supply circuit after the timer counter calculates the predetermined time. (2) The projection light source device according to claim 1, comprising a video signal processing circuit and a system control circuit, wherein while the timer counter is counting the predetermined time, a video mute signal is sent from the system control circuit to the video signal processing circuit. A video projection device that outputs a signal to a signal processing circuit and stops projecting the video. (3) The projection light source device according to claim 1, a character signal generation circuit, and a system control circuit, and while the timer counter is counting the predetermined time, a character generation instruction signal is not transmitted from the system control circuit. is output to the character signal generation circuit, and displays on the screen a warning to the effect that the power supply to the projection light source device will be stopped after a predetermined period of time has elapsed, and/or the remaining time until the power supply to the projection light source device is stopped. An image projection device designed like this. (4) The video projection device according to claim 2 or 3, further comprising a group of operation switches connected to a system control circuit and operated by a user, while the timer counter is counting the predetermined time. In the image projection apparatus, when a system control circuit detects that any one of the operation switches has been operated, counting of the timer counter is stopped and reset. (5) In the video projection device according to claim 2,
The system comprises a group of operating switches connected to a system control circuit and operated by a user, and the system detects that any one of the group of switches is operated while the timer counter is counting the predetermined time. When a control circuit detects this, the timer counter stops counting, resets the timer counter, and resumes projecting the image. (6) In the video projection device according to claim 3,
The system comprises a group of operating switches connected to a system control circuit and operated by a user, and the system detects that any one of the group of switches is operated while the timer counter is counting the predetermined time. When a control circuit detects this, the timer counter is stopped and reset, and a character generation instruction signal outputted to a character signal generation circuit is deactivated.