JPS6173000A - Light wave type proximity fuse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a light wave type proximity fuse used in guided missiles and artillery shells.

[Technical background of the invention and its problems]

There are various methods of proximity fuses used in artillery shells, but the existing methods have had problems with unstable operation. for example,
Radio-based radar systems sometimes malfunction due to reception of other radar waves, or malfunction due to radio interference.

Furthermore, even with the capacitive detection method, there is currently an instability in detecting target proximity.

[Purpose of the invention]

This invention was made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to accurately detect the direction of the target and the distance to the target, prevent malfunction due to interference waves and noise light, and accurately destroy the target. It is an object of the present invention to provide a light wave type proximity fuse that can be made at low cost.

[Summary of the invention]

The light wave type proximity fuse of this invention transmits light pulses of different frequencies modulated at frequencies lower than the optical frequency from a plurality of optical transmitters toward a target, and each light pulse is a reflected pulse from a target within a certain distance. The detonation signal is received by an optical receiver corresponding to the transmitter.

[Embodiments of the invention]

Embodiments of the light wave type proximity fuse of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. In FIG. 1, U1 to U3 are units, and each unit 01 to U3 is composed of an optical transmitter PT and an optical receiver PR, respectively. Optical transmitter PT and optical receiver P of each unit U1 to U3
R has the same configuration (however, the transmitting and receiving frequencies are different) in order to reduce the price, so I will explain the configuration on behalf of Uni, ) UJ @ Unit U1, A trigger signal is sent from the trigger generation circuit 1 to the burst oscillator 2 and the distance measuring circuit 3. When a trigger signal is input to the node oscillator 2, a burst signal having a frequency ft (lower than the optical frequency) that lasts for a certain period of time is outputted to the node oscillator 4.

The power amplifier 4 is adapted to drive a light emitting element 5 such as a Raded diode or a light emitting diode. The light generated by this light emitting element 5 passes through a transmission optical system 6 and becomes a transmission light (light) 7 having a modulation frequency fl, and is transmitted to a target (not shown). Thus, an optical transmitter PT is configured.

Next, the optical receiver PR will be described. The transmitted light 7 is irradiated onto the target and reflected light 8 passes through a receiving optical system 9 and an optical filter 10 and is received by a photodetector 11.

This photodetector 11 converts an optical signal into an electrical signal and sends it to the distance measuring circuit 3 through an amplifier 12 and a bandpass filter 13. The output of this distance measuring circuit 3 is passed through an amplifier 14,
The direction finding circuit 15 includes an amplifier (unit U1) of another unit U2, 0.3.
The direction detection circuit 15 outputs a detonation trigger signal 16.

In addition, from unit U2, transmission light 17 with a modulation frequency of 12 is transmitted.
is transmitted toward the target, and its reflected light 18 is sent to the unit U.
The light is received by the second photodetector. Similarly, a transmission light 19 having a modulation frequency f3 is transmitted from the unit U3 toward the target, and its reflected light 20 is received by the photodetector of the unit UJ.

Next, the operation of the light wave type proximity fuse of the present invention constructed as above will be explained with reference to FIG. 2. This second
The figure is a partial cross-sectional view of a flying object showing the operational status, and shows how the light wave type proximity tube of the present invention is arranged around the outer periphery of the flying object.

In this Figure 2, 21 is the outer casing of the flying object, 22.23
indicates the wing of the flying object, and the outer casing 21 of the flying object includes each transmission optical system 6, unit U2, unit U2, and so on.
Indicates that the receiving optical system 9 is installed◎
Further, A1 indicates the fielding range of unit U1, and A2 indicates the fielding range of unit U2.

In this way, each pair of optical transmitter iPT and optical receiver PR of each unit) Ul, U2,... is arranged at regular intervals such as radially as shown in Fig. 2. When each pair is placed in 6 locations, the area in charge of each pair (i.e. the area of defense in Figure 1)1. A,',... are 30 degrees when viewed from the center of the flying object's axis.

Now, each unit tJJ, u2. . . . outputs a trigger signal from the generation circuit 1 that should be the timing of transmission. In unit UJ, the burst oscillator 2 is triggered by the signal, and outputs a burst signal of frequency f1 that lasts for a certain period of time.

The burst signal is amplified by a four-power amplifier 4 so that the light emitting element 5 has an input sufficient to produce the required output.

Based on the output of the power amplifier 4, the light emitting element 5 has a predetermined power and emits an optical pulse modulated at a frequency f1. This light pulse is emitted to the outside as transmitted light 7 through the transmitting optical system 6. Generally, the light emitting pattern of the light emitting element 50, such as a light emitting diode or a laser diode, is 20° to 300° wide. Therefore, in the case of the system arrangement as shown in FIG. 2, it is acceptable to leave the light emitting turn as shown by the defense range AJ. The transmitted light 7 is transmitted toward a target, and the reflected light 8 from the target is first collected by a receiving optical system 9 so that it is collected on the photosensitive surface of the photodetector 1.

As shown in FIG. 2, the receiving optical system 9 includes each unit U.
z, 01. The field of view is determined so as to collect the target reflected light corresponding to the viewing angle in charge of ....

An optical filter 10 is inserted between the receiving optical system 9 and the photodetector 11. This optical filter 10 passes only light having the same wavelength as the transmitted light 7. This prevents sunlight and other noise light from entering the photodetector 11.

The reflected light 8 from the target that is incident on the photodetector 511 is photoelectrically converted therein and turned into an electrical signal.

This signal is amplified by an amplifier 12 and enters a bandpass filter 13. The pass frequency of this bandpass filter 13 is matched to the modulation frequency 11 during transmission.

This bandpass filter 13 may be constructed from a PLL.

This bandpass filter 13 selects only the reflected optical signals of the optical pulses sent out by the optical transmitter FT of the same unit (for example, unit Uz). The signal that has passed through the bandpass filter 13 is input to the distance measuring circuit 3.

The distance measuring circuit 3 may have a circuit configuration that detects whether a reflected light signal of a target is received from within a specific distance. The start signal for each pulse of the ranging circuit 3 depends on whether the bird is from the generating circuit 1, as shown in FIG.

A signal from the ranging circuit 3 indicating that the target reflected signal is coming back from within a specific distance passes through the amplifier 14 to the unit U.
It is input to the direction detection circuit 15 as a signal of I. Based on this signal, the direction detection circuit 15 determines that there is a target in the direction assigned to the unit U1. Then, a detonation trigger signal 16 is issued to detonate the detonation in the target direction, that is, in the direction of the unit U1. The same applies to units U2 and below. Note that when the detonator is not a directionally variable explosive, the direction detection circuit 15 may be a simple OR circuit.

〔Effect of the invention〕

As described above, according to the light wave type proximity fuse of the present invention,
It has the following advantages.

(1) The direction of the target can be detected by having multiple pairs of optical transceivers.

(2) Since the transmitted light is subjected to unique frequency modulation, malfunctions due to interference waves or noise light can be removed, and direction can be detected stably.

(3) Since the transmitted light uses light wave pulses, the distance to the target can be accurately detected.

(4) The circuit can be extremely simplified, the circuit part of each unit can be integrated into an IC, and if mass production is possible, the price can be reduced. Note that the modulation frequency can be set arbitrarily using an external resistor.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an embodiment of the light wave type proximity fuse of the present invention, and Fig. 2 is a diagram showing the operational status of the same light wave type proximity fuse.・・・
Burst oscillator, 3... Distance measurement circuit, 5... Light emitting element, 6... Transmission optical system, 7.17.19... Transmission light,
ll, 18.20... Reflected light, 9... Receiving optical system,
Jl...Photodetector, 15...Direction finding circuit, 21.
...Aircraft outer casing, kl. A2...Defense range.

Claims (1)

[Claims] A plurality of optical transmitters that transmit optical pulse-shaped transmitted light modulated at a frequency lower than the optical frequency and different from each other toward a target, and a fixed distance of each transmitted light provided corresponding to each of the optical transmitters. A light wave proximity fuze that consists of multiple optical receivers that receive the reflected light from a target within range and obtain a detonation signal.