JPH01260596A - Laser alarm device - Google Patents

Abstract

PURPOSE:To easily decide the existence of an object in the neighborhood of a light source by attaching a function to stop the emission of a laser beam source on another channel when the laser beam source on a certain channel is emitted and to emit each channel sequentially. CONSTITUTION:Delay circuits 2, 10, and 22, and latch circuits 7 and 15, and NAND gates 23 and 24 are provided. And while a time until a certain channel receives reflected or scattered light after emitting the laser beam, another channel emits no laser beam, and also, a timing between the emission of the laser beam and the stoppage of a reception function of each channel is shifted so as to stop the reception function by closing the gate of a signal processing part. In such a way, it is possible to increase the S/N of a reception signal by eliminating electromagnetic interference between the channels and to decide the existence of the object in the neighborhood of the light source easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser warning device, and particularly to a laser warning device that emits a laser beam and detects its reflected or scattered light.
! The present invention relates to a laser warning device that determines whether an object exists or is a stand near a light source based on the level of the light source and gives an early warning.

[Conventional technology]

Conventionally, this type of rake warning device includes a laser light source drive unit, a plurality of laser light sources driven by the laser light source, and a plurality of nine light receivers, and the light sources continuously emit light simultaneously in a pulsed manner, The alarm operation is performed by detecting reflected light or scattered light from an object near the light source using the light receiver.

[Problem to be solved by the invention]

However, since the conventional laser alarm device described above drives the laser drive unit or multiple laser light sources at the same time, the electromagnetic interference between each channel is large, and therefore the S/N ratio of the received signal is reduced. This has the disadvantage that it becomes difficult to determine whether or not there is an object near the light source. In addition, when multiple laser light sources are driven simultaneously)'::: /com, in the field of view of adjacent channels or in the overlapping region (', zli
- This means that the Rayleigh light is emitted with an intensity approximately twice that of the non-duplicated area, so whether there is an object near the light source or not γi
The disadvantage is that the criteria for determining this value vary depending on the angle.

Purpose of the invention? j Eliminate the above-mentioned P2 defects, eliminate electromagnetic interference between each channel, and increase the S/N of the received signal,
An object of the present invention is to provide a laser warning device i: which greatly facilitates and stabilizes the determination of the presence of an object near a light source.

[Means to solve the problem]

The apparatus of the present invention includes a plurality of l/- laser light sources that emit continuous pulsed laser light, a laser drive section that drives the laser light sources, and a laser light source that directs the emitted laser light to an object existing near the laser light source. In a laser warning device including a plurality of receivers that receive reflected or scattered light and form a pair (channel) with the laser light source, the period from when the channel creates the laser light until the channel receives the reflected or scattered light. The other channels do not emit laser light, and the signal processing section 1 is closed to stop the receiving function. [Embodiment] Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention, taking as an example the case where the number of channels is two. The embodiment shown in FIG.
The Tilley circuit f1. constitutes a 2-channel laser alarm circuit driven by f1. +2.

Rayleigh light source (],) 3, gate pulse generation circuit (1) 4. , Tilley circuit (3) 5, latch circuit ri4N]]G, latch circuit (3) 7, amplifier +1. +
8, a series of light receiver (1) 9 and AND gate 23, delay circuit f2+ 1.0, laser light source (2+
1. , 1, Kate pulse generation circuit (2+], 2
, delay circuit +4)] 3, latch circuit +2)
] 4, Latch times il! 8 f4. + 15, amplifier (2+ 1.6, receiver (2)], 7 and △
NDK-1-24 series and Tilley circuit f5)
22, 4't/h, 1] These H4 production delay circuits fil 2 .

f2) 1. o, (5) 22, latch circuit (
317'l (4,) ]-5 and 'AND gate 2
3.24 is the part directly related to the present invention.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

FIG. 2 is a diagram of main waveforms of the embodiment shown in FIG. The embodiment shown in FIG. 1 will be described below with reference to the waveform diagram shown in FIG. 2.

A tri-force pulse a generated by the laser light source driving section 1 is sent to the Tilley circuit (2), [2)' 10.

The delay circuit (1) 2 outputs the output of the delay circuit (1) 2, which is delayed by a time t, to the laser light source (1) 3 and the gate pulse generation circuit (1) 4 at the same time. Send.

Tilley circuit (2) 10 delays the tri-force pulse a by t2.
Send to 2. However, in this example, 1,1 ≠t2.
Let L2>1. Hereinafter, one channel from the Tilley circuit (], )'2 to the light receiver (1) 9 will be explained in order.

Gate pulse generation circuit (1'l 4 is a receiving ζ・) pulse = 5- Generates a pulse a to the gate pulse 1 and sends it to the latch circuit (1) 6
and is sent to the Tilley circuit (3) 5 at the same time.

Tiray 4F? 8 (3) 5 is a delay circuit (3
)5 output e and send it to latch circuit (1)6.

Each of the four latches (] 6 is turned on by the goo 1-pulse d, and the delay circuit (3) enters with a delay of t3.
) 5 is turned off by output e. Latch circuit (1) 6 output f
will occur.

In this way, the channel can be received via the AND cable 1.23 only while the latch circuit (1) 6 is open, and in this state, the output g of the optical receiver (1) 9 is transmitted to the amplifier (1) is amplified and supplied to the latch circuit (3) 7 as one output of the amplifier (1) 8.
) 7 in the on state. Also, if the amplifier (1) 8 output 11 is present or not, the latch circuit (3) 7 is held in the OFF state.

In this way, when the latch circuit (3) 7 is in the on state, if there is an input from the light receiver (1) 9, the latch circuit (3)
7 Generates and outputs output 1.

-〇- On the other hand, delay circuit (from 2+10 to receiver f2)]
, 8.

And the other channels ranging from AND keys 1 to 24 operate in exactly the same manner. However, when one channel is in a receivable state, the other is never activated, and the noise generated when one channel is activated is prevented from being input to the other channel. This is because, as is clear from the above description and from FIG. 2, the emission timings of the laser light sources (1) 3 , +2) and 1.1 are different.

As mentioned above, the a of the signal of the laser light source (because the light emission timing of 3, 2 and 11 is set to be different, it is difficult or not to be output from each channel).
In order to process the nd condition, it is necessary to latch the signal at least until the last channel to emit light is closed.

Is the latch circuit (3) 7. (4) 15 turned off at the same time? There is an output r of the tiller circuit f5) 22.

Conventionally, all channels were made to emit light at the same time, and the oven close to Game 1 was also done at the same time, and the problem that the noise generated when one channel is activated enters another channel and deteriorates the S/N is as follows. This will ensure that it is eliminated.

〔Effect of the invention〕

As described above, the laser alarm device of the present invention has a function that, when the laser light source of one channel is emitting light, the laser light source of the other channel stops emitting light, and each channel is caused to emit light in sequence. By adding , there is no electromagnetic interference between each channel and the
/N increases, which has the effect of making it easier to determine whether an object exists near the light source. Furthermore, since the fields of view of adjacent channels should overlap, there is an effect that the criterion for determining whether an object exists near the light source is constant regardless of the angle.

[Brief explanation of the drawing]

FIG. 1 shows a block diagram 1.1 showing an embodiment of the present invention. FIG. 2 shows a timing diagram of output signals from various parts of the embodiment shown in FIG. Co. Laser light source drive unit, 2. Delay circuit (]),
3. Laser light source (1), 4 Gate pulse generation circuit (
1), 5 Tilley circuit (3), 6 latch circuit (1)
, 7... Latch circuit (3), 8... Amplifier (1), 9
・・Photo receiver (1), 10 Tilley circuit (2), ]Core laser light source (2), ]2・・Gate pulse generation circuit (2+
, ], 3 Tilley circuit (4), 14... latch circuit (2), 15 latch circuit (4), ]6... amplifier 2
, ]7 Photoreceiver (2), 18. '19... Laser light, 2
0. ．． 2]・Reflected light/scattered light, 22・・Delay circuit (
5), 23.24...A, ND Kate.

Claims (1)

[Claims] a plurality of laser light sources that emit continuous pulsed laser light; a laser drive unit that drives the laser light sources; In a laser warning device that includes a plurality of light receivers paired with a laser light source (channels), after a certain channel emits laser light, other channels emit laser light until the reflected or scattered light is received. 1. A laser alarm device comprising means for shifting the timing of laser emission and reception function stop of each channel so that the reception function is stopped by closing the gate of the signal processing section.