JP2591667B2 - Laser pointer system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser pointer system in which a safety device for emitting a laser beam is added to a system for indicating a predetermined position by a laser beam.

[Conventional technology]

A laser pointer system that indicates a predetermined position on a screen as a red dot by a laser beam, for example, is widely used in various lectures and the like. When using such a laser beam as the indicating means, it is necessary to prevent the laser beam from directly entering the eyes of the audience, and when the laser beam enters the human eyes, eye dysfunction may occur. Very dangerous. In particular, great care must be taken when using the laser pointer in front of a large audience for those who have no knowledge of laser light or visual physiology.

[Problems to be solved by the invention]

In the conventional laser pointer system, since there is no safety device for the emission of the laser beam, the laser beam as described above may directly enter human eyes, which is extremely dangerous. Was.

The present invention has been made in view of such a problem, and provides a safe laser pointer system without a laser beam directly entering human eyes.

[Means for solving the problem]

A laser pointer system according to the present invention, in a laser pointer system that irradiates a predetermined position with a laser beam and instructs, a light emitting device that emits infrared signal light near a predetermined irradiation position of the laser beam is arranged,
The pointer main body is provided with a light receiving device that receives the infrared signal light and a control circuit that controls the emission of the laser beam based on the signal, and the laser beam is emitted only when the emission direction of the laser beam is in the direction of the predetermined irradiation position. Are fired.

[Action]

In the laser pointer system of the present invention, the control circuit can emit the laser beam only when the light receiving device of the pointer body receives the infrared signal light emitted from the vicinity of the predetermined irradiation position of the laser beam. At this time, the signal light can be received only when the pointer main body is oriented in the direction of the predetermined irradiation position.

〔Example〕

FIG. 1 is a block diagram showing the configuration of a laser pointer system according to one embodiment of the present invention. In the figure, 1
Denotes a semiconductor laser, and 2 denotes a converging lens system. The semiconductor laser 1 and the lens system 2 are mounted on a holder 3 also serving as a heat sink. 4 is APC (Auto Power Co
utrol) circuit, 5 a power source, 6 a light emitting device arranged near a predetermined irradiation position of the laser beam, and emits infrared signal (pulse) light of a predetermined frequency from the infrared LED 7. Reference numeral 8 denotes a light receiving device provided on the pointer main body.
Signal from the photodiode passes through the filter 9
Received at 10. A control circuit 11 controls the emission of the laser beam based on the signal received by the light receiving device 8. The control circuit 11 emits the laser beam only when the emission direction of the laser beam is in the direction of the predetermined irradiation position. It becomes possible.

FIG. 2 shows a case where a laser beam from the pointer body is irradiated on the screen. In the figure, reference numeral 12 denotes the above-mentioned pointer main body, and a laser beam emitted from the pointer main body 12 is irradiated on a screen 13, and a predetermined irradiation position is indicated by a red dot. The light emitting device 6 is mounted on the upper portion of the screen 13. In the drawing, reference numeral 14 denotes a directional pattern of the infrared LED 7 of the light emitting device 6, and reference numeral 15 denotes a directional pattern of the photodiode 10 of the light receiving device 8 provided on the pointer body 12.

Next, the operation will be described. An infrared signal light is always emitted from the infrared LED 7 of the light emitting device 6 provided on the screen 13 in FIG. When the pointer turns the laser beam emission direction of the pointer main body 12 toward the screen 13 in an attempt to indicate a predetermined place on the screen 13, the infrared signal light is received by the photodiode 10 of the pointer main body 12, and the After the optical signal is converted into an electric signal by the photodiode 10, the light emitting device 6 is filtered by the filter in the light receiving device 8.
Are selected. At that time, the visible component of illumination light or sunlight is cut by the filter 9 and the light receiving device 8
Since the DC component and the low-frequency component are cut in the signal, the selected signal has a high S / N. The frequency of the signal is set sufficiently higher than the power supply frequency.

The signal selected by the light receiving device 8 is amplified and input to the control circuit 11. This control circuit 11
Then, the input signal is logically determined, and as a result, the control signal is output to the APC circuit 4. The control signal controls the laser beam lighting switch to operate effectively only when the pointer body 12 is receiving the infrared signal light. In other words, the pointer body 12
The laser beam can be emitted only when is facing.
Therefore, the laser beam does not directly enter the eyes of the audience, which is very safe.

Here, the directivity of the infrared LED 7 and the photodiode 10 is as shown in FIG. 2, and when the direction of the pointer body 12 is A, the directivity pattern of both is maximum, and the signal from the light emitting device 6 Can be easily detected, and the laser beam can be irradiated on the screen 13. Also, when the direction of the pointer body 12 is B, the directional pattern on the light emitting side is slightly inferior, but since the maximum sensitivity is obtained on the light receiving side,
Similarly, a signal can be detected and a laser beam can be emitted. However, if the direction of the pointer body 12 is C
In this case, not only the directional pattern on the light emitting side is inferior, but also the sensitivity on the light receiving side is further reduced, making it impossible to detect a signal. Therefore, even if the lighting switch is pressed, the laser beam is not emitted, and the laser beam is prevented from directly entering the human eyes. Generally, the directional pattern on the light-emitting side affects the position of the pointer body 12, and the directional pattern on the light-receiving side affects the direction of the pointer body 12, but these elements are optimized so as to be suitable for each use situation. Just set it.

In the above embodiment, the semiconductor laser 1 is used as the pointer. However, a pointer using a gas laser such as He-Ne can also have the same configuration, that is, the light emitting device 6, the light receiving device 8,
By using a configuration in which a safety device including the control circuit 11 and the like is added, the eyes of the audience can be protected from the laser beam. This system is also suitable for displaying graphics in various shows and the like and for giving instructions in various experiments and measurements.

〔The invention's effect〕

As described above, according to the present invention, a light emitting device for infrared signal light is provided near a predetermined irradiation position of a laser beam, and a light receiving device for the infrared signal light is provided on a pointer body.
Since the laser beam can be emitted only when the pointer body receives the signal light directed to the irradiation position, the laser beam does not directly enter human eyes, does not cause eye dysfunction, and is safe. There is an effect that there is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a laser pointer system according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a state in which a laser beam is irradiated on a screen. DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser 4 ... APC circuit 5 ... Power supply 6 ... Light emitting device 7 ... Infrared LED 8 ... Light receiving device 9 ... Filter 10 ... Photodiode 11 ... Control circuit 12 ... Pointer body 13 ... …screen

Claims (1)

(57) [Claims] 1. A laser pointer system for irradiating a predetermined position with a laser beam to indicate a position, a light emitting device for emitting infrared signal light is provided near a predetermined irradiation position of the laser beam, and a pointer body is provided. A light receiving device for receiving the infrared signal light and a control circuit for controlling the emission of the laser beam based on the signal are provided, and the laser beam is emitted only when the emission direction of the laser beam is in the direction of the predetermined irradiation position. A laser pointer system characterized by being configured as described above.