Projectors with security area detection

A projector comprising a light engine, a detector, and a control unit is disclosed. The light engine comprises a light source and generates a projection beam based on the light from the light source. The space which the projection beam passes through is defined as a projection area, and a security area is defined by the projector to include or overlap the projection area. The detector detects whether a living organism is in the security area or not. When the detector detects a living organism in the security area, the detector generates a warning signal and transmits the warning signal to the control unit. After receiving the warning signal, the control unit directs the projector to enter a security mode to protect the living organism from being hurt.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a projector and a safe operation method thereof.

2. Description of the Related Art

As the light source of the projector is high-powered, human eyes may be hurt by projection beams from the projector when the projection beams directly shining into the human eyes.

Conventional projectors do not protect human eyes from being hurt by the strong projection beams from the projector. Therefore a method for protecting users is required.

BRIEF SUMMARY OF THE INVENTION

In order to solve the above shortcomings, in one embodiment of the invention, a projector comprises a light engine, a detector and a control unit. The light engine comprises a light source, and generates a projection beam based on the light provided by the light source. The space which the projection beams pass through is defined as a projection area. A security area is defined by the projector to include or overlap the projection area. The detector is used for detecting whether a living organism is in the security area or not. When the detector detects a living organism in the security area, the detector generates a warning signal and transmits the warning signal into the control unit. After receiving the warning signal, the control unit directs the projector to enter a security mode.

In one embodiment of the invention, a method of safely operating the projector. The safe operation method comprises using the detector to detect whether a living organism is in the security area or not. The detector generates a warning signal when detecting a living organism being in the security area. After receiving the warning signal, the control unit directs the projector to enter a security mode.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a projector in one embodiment of the invention. The projector100comprises a light engine114, a detector104and a control unit106. The light engine114comprises a light source102. Based on the light provided by light source102, the light engine114generates projection beams. The space which the projection beams pass through is defined as a projection area. A security area is defined by the projector100to include or overlap the projection area. The detector104detects whether a living organism is in the security area or not. When a living organism is detected in the security area, the detector104generates a warning signal112and transmits the warning signal112to the control unit106. After receiving the warning signal112, the control unit106directs the projector100to enter to a security mode to avoid hurting the living organism.

The detector104may be an infrared ray sensor or a face detection camera. The infrared ray sensor can distinguish organisms/items with temperature of 30° C.˜40° C. The face detection camera can be implemented by a CCD camera comprising a CCD sensor and a face detection unit. The CCD sensor takes the picture of the security area and then transmits the picture to the face detection unit. The face detection unit is used for distinguishing if there is a human face in the security area to determine if there is a human in the security area.

The light source102may be a laser. Because the laser is immediately usable without warm-up, the control unit106can directly turn off the laser102when the detector104detects a living organism in the security area.

In another embodiment, the light source102is a high-pressure mercury lamp. Because the high-pressure mercury lamp requires a period of time to warm-up, which is time consuming, the projector further comprises a photo-degradation device108. When the detector104detects a living organism in the security area, the control unit106controls the photo-degradation device108to degrade the light from the high-pressure mercury lamp (102).

In another embodiment, the projector100further comprises a horn110. When the detector104detects a living organism in the security area, the control unit106sounds the horn110to warn the living organism.

In some embodiments, the security area is designed to be wider than the projection area (as that shown inFIG. 2). The projection of the projector202may be projected in the projection area204. It is dangerous to stand within the projection area since the projection beams may hurt human eyes. As the embodiment shows inFIG. 2, a security area206is designed wider than the projection area204so that the projector202can warn organisms in the security area before he/she enters the projection area. In this embodiment the projector comprises a horn110and the light source102is a laser, the control unit106sounds the horn110when the detector104detects a living organism being in the security area206and, when the detector104detects the living organism being in the projection area204, the control unit106directly turns off the laser. In another embodiment the projector comprises a horn110and the light source102which is a high-pressure mercury lamp, the control unit106sounds the horn110when the detector104detects a living organism being in the security area206and, when the detector104detects the living organism being in the projection area204, the control unit106uses the photo-degradation device108to degrade the intensity of the light from the high-pressure mercury lamp.

One embodiment of the invention further provides a method of safely operating the projectors. The block diagram of the projector is shown inFIG. 1, which comprises a light engine114, a detector104and a control unit106. The light engine114comprises a light source102. According to the light from the light source102, the light engine114generates projection beams. The space which the projection beams pass through is defined as a projection area. A security area is defined by the projector to include or overlap the projection area.

FIG. 3illustrates the flowchart of the safe operation method in one embodiment of the invention. In step S302, the detector104is used for detecting whether a living organism in the security area or not. When the detector104detects a living organism in the security area, step S304is executed. In step S304, the detector104generates a warning signal and transmits the warning signal to the control unit106. In step S306, the control unit106directs the projector to enter a security mode after receiving the warning signal. When the detector104detects no living organism in the security area, the method repeats step S302to continue detecting the security area. The detector104may be an infrared ray sensor or a face detection camera.

In an embodiment of the projector includes a laser as the light source, the safe operation method directly turns off the laser in the security mode. In another embodiment of using a high-pressure mercury lamp as the light source, the safe operation method provided provides a photo-degradation device and uses the photo-degradation device to degrade the intensity of light from the light source in the security mode.

The safe operation methods in some embodiments of the invention further comprises a horn for sounding when the detector detects a living organism in the security area.

The safe operation methods in some embodiments of the invention design the security area to be wider than the projection area (as that shown inFIG. 2). In these embodiments, the safe operation method comprises sounding the horn when the detector detects a living organism entering the security area206and degrading the intensity of the light provided by the light source when the detector detects the living organism entering the projection area204. In an embodiment of the invention, the projector includes a laser as the light source, the intensity of the light provided by the light source (laser) can be degraded by directly turning off the laser. In another embodiment of the invention, the projector includes a high-pressure mercury lamp as the light source, the intensity of the light provided by the light source (high-pressure mercury lamp) can be degraded by a photo-degradation device.