JPH089700Y2 - Laser pointer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a laser pointer device, and in particular, a laser beam generated by a semiconductor laser is condensed by an optical system to form a light beam, which is projected onto a projection surface. The present invention relates to a laser pointer device that gives instructions.

[Conventional technology]

Conventionally, in this type of laser pointer device, the laser output is a relatively large constant value so that the bright spot formed by the projection of the light beam can be clearly recognized even on a bright projection surface such as the projection surface of an overhead projector. Was set to.

[Problems to be solved by the device]

In the conventional laser pointer device described above, the laser output is set to a relatively large constant value, so that when the light beam is projected onto a dark projection surface such as the wall surface of the planetarium, the laser output is high. There was a problem that the size of the bright spot that was visually observed was too large.

Further, since the laser output is set to a relatively large constant value, there is a problem that the power consumption is large and the life of the power source is shortened in the case of battery driving.

In view of the above points, an object of the present invention is to change the laser output according to the brightness (illuminance) of the projection surface so that the size of the bright spot that is visually recognized is almost constant regardless of the brightness of the projection surface. It is another object of the present invention to provide a laser pointer device in which power consumption is reduced by reducing power consumption.

[Means for solving the problem]

The laser pointer device of the present invention is a laser pointer device for directing an instruction by projecting a laser beam generated by a semiconductor laser by an optical system into a light beam and projecting the light beam on the projection surface. An illuminance sensor for measuring, and an electronic circuit for increasing the laser output of the semiconductor laser when the illuminance of the projection surface is high according to the output of the illuminance sensor and for reducing the laser output of the semiconductor laser when the illuminance of the projection surface is low. Characterize.

[Action]

In the laser pointer device of the present invention, the illuminance sensor measures the illuminance of the projection surface, and the electronic circuit increases the laser output of the semiconductor laser when the illuminance of the projection surface is high according to the output of the illuminance sensor, and the illuminance of the projection surface is low. Reduce the laser output of the semiconductor laser.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a laser pointer device according to an embodiment of the present invention. The laser pointer device of the present embodiment is a projection optical system 2 including a semiconductor laser 1 that generates visible laser light and a lens that condenses the laser light generated by the semiconductor laser 1 into a parallel light beam.
Of the photoelectric conversion element 3 that measures the illuminance of the projection surface near the bright spot S formed by the laser light projected on the projection surface P, and the projection surface near the bright spot S on the photoelectric conversion element 3. A photometric optical system 4 including a lens for entering light for measuring illuminance, an electronic circuit 5 for controlling the semiconductor laser 1, the photoelectric conversion element 3, etc., a semiconductor laser 1, a photoelectric conversion element 3, an electronic circuit 5, etc. A main part of the power source 6 is a battery such as a dry battery for driving the laser and a casing 7 of the laser pointer device. The photoelectric conversion element 3 and the photometric optical system 4 form an illuminance sensor that measures the illuminance of the projection surface P in a spot shape.

Referring to FIG. 2, the semiconductor laser 1 has an electronic circuit 5
Is connected to the semiconductor laser drive circuit 8 in the
The light emission is driven by the drive current from the. Further, the photoelectric conversion element 3 is connected to a low-pass filter (hereinafter abbreviated as LPF) 9 in the electronic circuit 5, and the output from the photoelectric conversion element 3 is waveform-shaped through the LPF 9 to the semiconductor laser drive circuit 8. It is being supplied.

Next, the operation of the laser pointer device of this embodiment having the above configuration will be described.

The laser light generated by the semiconductor laser 1 is condensed by the projection optical system 2 and projected on the projection surface P as a parallel light beam.

At this time, the light near the bright spot S formed on the projection surface P by the projected light beam is incident on the photoelectric conversion element 3 by the photometric optical system 4, and the illuminance near the bright spot S on the projection surface P is increased. Is measured by the photoelectric conversion element 3. That is, the photoelectric conversion element 3 generates a current or voltage output according to the illuminance in the vicinity of the bright spot S on the projection surface P (see FIG. 3A), and this output is waveform-shaped by the LPF 9. (See FIG. 3 (b)), it is input to the semiconductor laser drive circuit 8.

The semiconductor laser drive circuit 8 increases the current supplied from the power source 6 to the semiconductor laser 1 so that the laser output of the semiconductor laser 1 increases according to the output from the LPF 9 when the illuminance on the projection surface P is high, and the projection is performed. If the illuminance on the surface P is low, the current supplied from the power source 6 to the semiconductor laser 1 is reduced so that the laser output of the semiconductor laser 1 is reduced, and the laser output of the semiconductor laser 1 is formed on the projection surface P by the light beam. The bright spot S is adjusted so that the size of the bright spot S is visually recognized to be substantially constant (see FIG. 3C).

Therefore, a bright spot S due to a light beam having a large laser output is obtained on a bright projection surface P such as the projection surface of an overhead projector, and a small laser output is generated on a dark projection surface P such as a wall surface of a planetarium. The bright spot S by the light beam is obtained,
Bright spot S of almost the same size in any environment
Will be visible as.

Further, when the light beam is projected on the relatively dark projection surface P, the laser output of the semiconductor laser 1 is reduced, so that the power consumption is small and the power saving of the laser pointer device is achieved. , The life of the power source 6 can be extended when it is driven by a battery such as a dry cell.

[Effect of device]

As described above, according to the present invention, the illuminance sensor for measuring the illuminance on the projection surface is provided, and the laser output of the semiconductor laser is changed according to the illuminance on the projection surface. Even underneath, there is an effect that it is possible to control so that the bright spots on the projection surface are visually recognized to have substantially the same size.

Also, compared to the case of the conventional laser pointer device in which the laser output is set to a relatively large constant value so that the bright spot can be visually recognized on any bright projection surface, the light beam is projected on a relatively dark projection surface. In the case of projecting, the laser output of the semiconductor laser is reduced and the power consumption is small, so that the power saving of the laser pointer device is achieved, and the life of the power source can be extended in the case of battery driving such as dry battery. There is an effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a laser pointer device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the circuit configuration of the laser pointer device of this embodiment, and FIGS. 3 (a)-(c). 10] is a diagram showing the output of each part in the laser pointer device of the present embodiment. In the figure, 1 ... Semiconductor laser, 2 ... Projection optical system, 3 ... Photoelectric conversion element, 4 ... Photometric optical system, 5 ... Electronic circuit, 6 ... Power supply, 7 ... Housing, 8 ... Semiconductor laser drive circuit, 9 ...
LPF, P ... Projection surface, S ... Bright spot.

Claims (1)

[Scope of utility model registration request] 1. A laser pointer device for directing an instruction by projecting a laser beam generated by a semiconductor laser by an optical system into a light beam and projecting the light beam onto a projection surface. An illuminance sensor for measuring the illuminance of the projection surface. And an electronic circuit that increases the laser output of the semiconductor laser when the illuminance of the projection surface is high and decreases the laser output of the semiconductor laser when the illuminance of the projection surface is low according to the output of the illuminance sensor. Laser pointer device.