JPS58131578A - Lightwave ranging method and device - 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 The present invention provides a light wave that accurately measures the distance to a point to be measured based on the one phase difference between the nine modulated light waves that are sent to a point to be measured and the nine modulated light waves that are reflected and returned from the point to be measured. This invention relates to a distance measuring method and device.

In recent years, light wave distance needles have come into widespread use for distance measurement, mainly in the field of surveying. A light wave distance meter sends a light wave modulated at a predetermined modulation frequency to a reflector consisting of a coupe installed at a measurement point, and receives the light wave that is reflected by the reflector and returns. , the distance to the measurement point is measured from the phase difference between the received light wave and the transmitted light wave.

At present, a light emitting diode is used as a light emitting source for a light wave distance needle due to the demand for a smaller and lighter device. However, the maximum possible tooth length distance IIIF' of the optical distance meter
Since it is determined by the brightness of the source, the maximum measurable distance for a light-wave distance meter using a light emitting diode is 2 to 5.
km was the limit.

For optical distance meters for longer distance measurements, He
-Ne was used as a slave, but on this day -
N@f When using a Slede as a light source, the Leded tube is large h
This not only leads to larger equipment, but also requires a high-voltage, high-capacity power source, which is inconvenient for surveying the outside of the eruption.Furthermore, it increases temperature costs, shocks (weakness, and radiation fragility).
It was also necessary to use an electro-optical element such as an OP to modulate the light.

In recent years, with the advancement of semiconductor technology, semiconductor radars have become capable of manual eq. If this semiconductor radar is used as a light source for a light wave distance meter, a high-intensity light source similar to a conventional Pslade can be obtained, and the maximum measurement The possible distance can be greatly extended, the size and power consumption are comparable to conventional light emitting diodes, and furthermore, since the semiconductor radar 1 blue can be modulated, not only does it require no special modulation means. It has various advantages such as a faster light emission response speed than a light emitting diode, a higher modulation frequency, a higher measurement accuracy, and a wave distance needle.

However, if semiconductor radar is used as a light-wave distance meter,
i. When used in a closed manner, the following problems arise. In other words, when a rectangular modulated wave is applied to a semiconductor laser to emit modulated light, the waveform of the modulated light is not exactly rectangular but becomes a book with a different shape depending on the exit angle. It has a wavy shape with sharp protrusions on the shoulders,
Light with a different exit angle has a medium-high waveform with a bulge in the center, and light with a different exit angle has a waveform with a bulge in the front half.The wave IF of such a modulated wave
? The difference between the two means that the fundamental wave component, the sine wave, has a different phase. For this reason, the measurement results will differ depending on which exit angle the light receiving section receives the light.

By the way, in actual distance measurement using a light wave distance meter, a reflector such as a corner cube placed at a measurement point is not always placed under the same conditions with respect to the light wave distance meter. For example, if the corner cube is disposed laterally offset from the optical axis, the light rays incident on the light receiving element and involved in measurement will have different exit angles. Furthermore, since the light beam emitted from the objective lens of a light wave distance meter is not completely parallel but has some spread, the light rays involved in the measurement change depending on the measurement distance. Furthermore, changes occur due to slight tremors and air fluctuations in the installation site where the corner cube is installed. These changes in the light beams involved in the measurement will cause differences in the measurement results based on the differences in their waveforms.

Furthermore, in the case of conventionally used light emitting diodes, their light emitting area is larger than that of semiconductor lasers, so it is well known that a difference in the phase of modulated light occurs due to the differential pressure at the emission point. In light wave distance meters using light emitting diodes, various types of phase mixing devices have been proposed to solve this problem of phase difference between modulated light. These phase mixing devices are based on optical distance [tiK] using light emitting diodes.
However, the problem can be solved to some extent.

This method is not effective in solving the above-mentioned problem in a semiconductor laser, which has a very small area of a light emitting part and can be expected to serve as an almost perfect point light source.

The present invention solves the problems of the light emitting source in the conventional light wave WiIll* (in view of this, it is a round thing, and the first problem is
It is an object of the present invention to provide a new light wave distance measuring method and apparatus in which differences in phase difference between emitted light beams emitted from a light emitting source due to different types of emitted light beams do not contribute to errors in distance measurement data.

The second object of the present invention is to significantly improve the conventional light-wave distance meter without making any changes, and to eliminate the effect of phase difference changes between emitted light beams on the error pressure of distance measurement data compared to the conventional light-wave distance meter. It is an object of the present invention to provide a more accurate optical distance measuring device.

Furthermore, the third object of the present application is to solve the problem that when a semiconductor radar is used as a light emitting source, the phase difference change between the emitted light beams depending on the emitting angle causes an error in distance measurement data, and to fully put it into practical use. Not only that, it is smaller, lighter, consumes less power, and has a longer maximum measurement distance than conventional light-wave distance meters that use light-emitting diodes or lasers as light sources.
The object of the present invention is to provide a nine-wave distance meter using a semiconductor laser as a light emitting source with high measurement accuracy.

That is, the present invention includes a step of emitting a distance measuring light beam from a light emitting source driven at a predetermined modulation frequency, a step of transmitting the distance measuring beam to a point to be measured by an optical means, and a step of transmitting the distance measuring beam to a point to be measured. A step of receiving the reflected light beam from the distance measuring light beam reflected from the point, and a light wave measurement step of measuring the phase difference between the reflected light beam and the distance measuring light beam, and measuring the distance to the distance measurement point from the phase difference. In the ranging method, in order to eliminate the influence of a plurality of ranging light beams with different waveforms inevitably generated from the light emitting source, a ranging optical path formed by the ranging light beam and the reflected light beam is
The present invention provides a light wave distance measuring method in which at least one of the distance measuring light beams is propagated at a different time from other distance measuring light beams.

Furthermore, the present invention includes a light emitting source that is driven at a predetermined modulation frequency and emits a distance measuring light beam, a rounded optical means that sends the distance measuring light beam from the light source to a point to be measured, and a phase difference measuring means for receiving the reflected light beam from the distance measuring light beam reflected at the distance measuring point and measuring a phase difference between the distance measuring light beam and the reflected light beam; In a light wave distance measuring device comprising a calculation means for calculating, a plurality of distance measuring light beams having different waveforms inevitably generated from the light emitting source are formed by a distance measuring light beam and a reflected light beam. The present invention provides a light wave distance measuring device characterized in that it includes a mixing means for causing propagation in a distance measuring optical path at different times.

In the present invention, "distance measuring light rays with different waveforms" includes both cases where the shapes of the output waveforms differ depending on the light rays, and cases where the output waveforms have the same shape but differ only in phase. used for meaning.

According to the above-mentioned features of the present invention, even in conventional light wave ranging methods and devices that use light emitting diodes as a light source, higher accuracy can be obtained than in conventional methods. , it also opens the way to practical use of a light wave distance measurement method that uses a semiconductor laser as a light emitting source and its loading, making it possible to greatly extend the maximum measurement distance compared to light-emitting diode TIG light wave distance measurement devices. , and high ranging accuracy can be obtained. In addition, compared to conventional slave-type light wave ranging devices, it is smaller, lighter, consumes less power, and can be used for long-term surveying outdoors. It is possible to provide an extremely useful new optical distance measuring device that does not require any elements or the like.

Embodiments of the present invention will be described in detail below with reference to the drawings. Note that in the following embodiments, only the case where a semiconductor laser is used as the waste light source will be explained, but the present invention is not limited to this, and the present invention is similarly applicable to the case where a light emitting diode is used as the light source.

FIG. 1 shows an example K of a light wave range finder as an example of a light wave range finder according to the present invention, and its configuration is shown in a block diagram. Brancher 10Fi oscillator] Signal from 1 15 MHz
to generate two signals, 75 kHz and 3 Hz. The synthesizer 13 calculates the difference between 15 MHz from the transmitter 11 and 3 Hz from the branch unit 1o (15 MHz - 5 Hz)
It generates a signal of 14.997 M)k per minute and a signal of 72 Hz, which is 24 times H2 from 3 to 1 B10 per minute. The first switch 14ti outputs a signal of either 15 MHz or 75 Hz depending on the signal 16 from the ring control circuit 15. A semiconductor radar 18 disposed within the mixer part 17 is driven by the output signal of the first switch 4 and emit modulated light, and an optical expander 21 consisting of a lens 19 and a lens 2o is used to generate an odometer. Rufaino 4
22. The modulated light emitted from the optical fiber 22 is emitted into either the distance measurement optical path 23 or the internal reference optical paths 2 and 4 by a filter 25 that switches between the distance measurement optical path 23 and the internal reference optical path 24. When the distance measuring optical path 23 is selected, the modulated light is reflected by the slope 261 of the prism 26, and then converted into a parallel beam by the objective lens 27, and then reflected by the reflector R, such as a corner cube, installed at the point to be measured.
The destination is sent out. The reflected light from the reflector R passes through the objective lens 27 and the slope 26b of the prism 26, enters the optical fiber 28, and is received by the light receiving element 30 consisting of an avalanche photodiode via the optical extender 29. When the internal reference optical path is selected by the shutter 25, the modulated light emitted from the optical fiber 22 is reflected by the internal reflection surface 26c of the prism 26, and is directly connected to the optical fiber 2.
8, and is received by the light receiving element 30.

This internal reference optical path is used to prevent errors in the distance measurement data due to phase changes due to temperature drift of the electric circuit that constitutes the optical distance meter itself, so the values measured by the internal reference optical path are By subtracting K from the measured value, accurate ranging data is obtained.

The second switch 31F1 outputs a signal of either 14, 9?7 MHz or 72 KHz depending on the signal 16 from the processing control circuit 15. The output from the light receiving element 30 is amplified by an amplifier 1132 via a co/capacitor 50 and input to a mixer 33. Mixer 33 mixes the signal from amplifier 32 and the second
A short repeat signal is created by mixing the signals from the switch 31, which is detected and a 5 KHz sine wave is output.

The waveform shaper 34 shapes the 3Hz sine wave into a rectangular wave and outputs a 9 signal (hereinafter referred to as a beatdown signal).The dart circuit 35 starts with a 5Hz signal from 41110. , the signal from the waveform shaper 34 is used as a stop signal, and the oscillation between [111 to 15
A MHz signal is output to the needle teaching device 36. This signal is Jl! The phase difference is measured by counting at 136.

The count value obtained by the counter 36 is the total number of N measurements. In order to know the number of N times, a 3 Hz signal from the branching device 10 is supplied to the processing control circuit 15. When counting N times is completed, a reset signal 37 is supplied from the processing control circuit 15 to the counter 36, and the counter 36 enters the FiIJ set state. The count value of N measurements is multiplied by 1/H in a processing control circuit to obtain an average value, converted to a distance, and displayed on the display 39 as a measured distance value.

In order to set the output of the mixer 33 to 3 Hz, the output signal of the first switch 14 and the output signal of the second switch 31 are 14 and 997 MHz, respectively, when the frequency is 15 MHz.

It is controlled by the signal 16 from the processing control circuit 15 so that when the frequency is 75 KHz, the relationship is 72 Hz. By modulating the semiconductor laser 18 at two frequencies, 15 MHz and 75 KHz, 15 MHz corresponds to a wavelength of 20 WLK.
This is because it is used for precise measurements, and 75 corresponds to H2Fi wavelength 4- and is used for rough measurements. The reason why the frequencies of 15 MHz and 75 Hz are set to 3 Hz in the mixer 33 is to increase the resolution of phase measurement.
This is to measure the phase at KHz.

The semiconductor laser 18 used as a light source in this example emits modulated light with different waveforms depending on the emission angle.

Figures 2 (a), (b), and (c) ij are examples. These nine different waveforms of modulated light have different phases in the sine wave, which is the basic component, and the measurement results differ depending on which modulated light K reaches the light receiving section.

The mixer part 17ti allows modulated lights with different emission angles to be emitted to the distance measuring optical path one after the other in time and reach the light receiving section via the reflected optical path, and has the optical fiber 22 as described above.

The optical fiber /4-22 of the mixer part 17 is wound several times in a coil shape, and one side of the annular portion is in contact with the pressing piece 40, and the opposite side has a piston 41m of the vibrator 41. The vibrator 41 is vibrated by being driven by an oscillation source 42 that is not synchronized with the modulated wave signal.

The mixing effect of the light emitted from the semiconductor laser 18 due to the vibration of the optical fiber 22 is schematically shown in the third diagram.
Shown in Figures (a), (b), and (C). semiconductor laser 1sf
i It is modulated with a rectangular modulated wave as shown in Fig. 4(a), and at any time, for example, the second
A ray with a modulated output waveform shown in Fig. 2(b) is outputted at an exit angle θ2, and a ray ^ with a modulated output waveform shown in Fig. 2(b) is also outputted at an exit angle θ3. (c>K
It is assumed that light rays C having the modulated output waveforms shown are respectively emitted. When each of the emitted light beams is incident on the vibrating optical fiber 22 via the optical extractor/mother 21, at a certain time t1, the emitted light is emitted from the optical fiber 22 as shown in FIG. 3(a). light is at angle 0
The ray ^ from 1', the light @ sun from the angle θ'2, the angle θ'
The light aC is emitted from the angle 01' at time t2, and the light aC is emitted from the angle 01' at time t2, as shown in the f83 diagram (1)).
The light @C is emitted from the angle 02', and the light ray @C is emitted from the angle 03', and furthermore, at time t3, as shown in Fig. 3 (
c) As shown in K, the ray C from the angle 01' is at the angle θ
A ray ^ is emitted from the angle 2/, and a ray 3 is emitted from the angle -5'. Such busy optical fiber 22
Due to the busy vibration of the tube, the rays ^, B, and C that are emitted from a certain angle lt, for example, the angle S or h of #1' are randomly mixed. This state is shown in FIG. 4(b)K.

Figure 4(e) is the semiconductor radar 1 shown in Figure 4(a).
8 is a diagram showing a sine wave that is a fundamental component of a rectangular modulated wave added to FIG.

The fundamental sine wave of the modulated output waveform of the emitted light beam from the angle #ll is the phase difference between the modulated wave applied to the semiconductor radar and the modulated wave output waveform that changes from time to time as shown in Diagram 4 (d3). becomes a sine wave that changes momentarily as Δ0, m., Δ.However, the waveform shaper 3 used for phase difference measurement
Since the beatdown signal from 4 has a much lower frequency than the modulated wave, the phase difference of the beatdown signal is calculated by calculating the average value of the phase difference of each light beam to be mixed by the phase difference Δ
The beatdown signal becomes 0 (4th s(e), (1
)) *This is common to all light beams 11 with an exit angle of I2' and 111, and applies to all extracted rays of exit angle that exit the optical 7-eyeper 22.The mixing effect is of the same type. The higher the frequency c at which the modulated waveform repeatedly appears in a certain direction (referred to as the beam switching frequency) is higher than the frequency of the averaging means, the more effective it is.

FIG. 4(b) shows an example in which the beam switching frequency is lower than the modulation frequency, but the opposite is true, FIG. 4(a/)~
(f") ii. This is a diagram corresponding to FIG. 4 (al to (f)) when the beam switching frequency is higher than the modulation frequency. In this case, the output waveform of the modulated wave emitted and pulled from the angle of 01' is , as shown in Figure 4 (b'), a mixing effect appears within the period of the modulated wave, and the fundamental sine wave is mixed as shown in Figure 4 (d'). is 75
Optical fiber 2 that vibrates light from a semiconductor radar IB modulated at a modulation frequency of Hz at a frequency of 1KHz.
This is a photograph of a book in which the emitted light when the light is incident on the synchro fuso is synchronized at 75 KHz and displayed on the screen of the Synchros Fuso. It becomes a waveform. This means that the phase difference of the beatdown signal from the waveform shaper 34 remains the same regardless of the exit angle.

In the light wave distance needle, the phase is measured many times and the average value is obtained by the processing control circuit 15, which is used as the final forging result, so that the above-mentioned light beam switching frequency is sufficiently effective even if it is not high. In other words, the light beam switching frequency may be sufficiently fast compared to the time it takes to perform a large number of phase measurements to obtain one measurement value.

If the beam switching station wave number is lower than the time required to perform phase measurement to obtain one measurement value, the measurement data will vary. Therefore, it is desirable that the beam switching frequency be sufficiently higher than the time during which phase measurements are taken.

However, as shown in the modulation waveform shown in Fig. 5, it is not necessarily necessary to increase the beam switching frequency K and temporally average the nine beams; the first phase measurement is made with the beam ^, and the second The phase measurement is done with light 41B, and the third phase measurement is done with light beam C.
As shown in Fig. 4, phase measurements are performed using different light beams, and a measured value is obtained from the average of the phase measured values.

FIG. 6 shows the results of an experiment on the accuracy of distance # measurement of a light wave distance meter using the mixer section 17 of FIG. 1, and a comparison of the effects of a part of the mixer.

The light wave distance meter has distance m measurement data at a modulation frequency of 75 t-Hz for rough measurements and 15 m for precise measurements.
The distance measurement data at a modulation frequency of 75 Hz and the distance measurement data at a modulation frequency of 15 Hz are combined to form the final measurement data, but the experimental data in Figure 6 is combined with the measurement data at 75 Hz and 15 M) to make it easier to understand.
Measurement data for lz are listed separately.

Figure 6 (a), ←) Vi shows the data when the optical fiber 22 of the mixer part 17 is not vibrated without the vibrator 41 being powered, and (a) is H at 75.
2 measurement data, 15 M) - 1z measurement data tube, the vertical axis is the measured distance value, and the horizontal axis is the number of measurements from the 1st measurement to the nth measurement, etc. It is.

FIGS. 6(c) and 6(d) show that the optical fiber 22 of the mixer s17 is photographed using the nonoblator 41 (
This is the measurement result when the 6th
Figure (C) shows the measurement data of lz, and (d) shows the measurement data of 15.
This is MHz measurement data. In the measurement, a reflector was installed at a position of 17 m from the main body of the light wave distance meter, and the distance between the two was measured. As can be seen from the measurement results in Figures 6(a) and (b), if the mixer part 17 is not operated, it will be affected by slight vibrations at the installation location and fluctuations in the air, resulting in unevenness of the light beam involved in the measurement. This affects the 141 measurement data, and the variation in the measurement distance data is large. on the other hand,
1lE6 Figures (c), (d) ノ1IIQ? As is clear from the results, when some of the mixers 17 are electrically driven, the variation in the measured distance data is almost eliminated.

In general, in order to avoid the influence of electric circuit temperature (FQ), etc., an optical distance meter is provided with an internal optical path 24 inside the device as shown in FIG. A part of the luminous flux is transported.

When the distance measuring optical path 23 and the internal optical path 24 are formed as two separate optical paths in this way, the waveforms of the light beam passing through the distance measuring optical path and the light beam passing through the internal optical path will be different if the mixing part 17 is not present. Even if you attempt to obtain accurate distance measurement data by subtracting the phase difference of the internal optical path from the phase difference of the edge optical path, the distance data will be inaccurate because the light flux passing through both optical paths is different. Appears as an offset value. especially s 75
The offset value of measurement data using KHz modulated light waves must be considered important. Generally, H to 75.

When combining the data of 15 MHz and 15 MH2 to include the final result, add or subtract a value of about 1 m or less to the 75 KHz data so that the metric units match. The measurement results in Figure 6 (a) show an average of about 18 m, while the measurement results in Figure 6 (b)
indicates an average length of approximately 7.1 m. For example, ta6 diagram (a)
If there is a difference of 1m or more in meters, as in the 01st and 2nd s1 constant data of
It becomes impossible to synthesize 15 MHz data and 15 MHz data. On the other hand, FIG. 6(e) shows a measured distance value of about 17.8 m, and FIG. 6(d) shows a distance of about 7.877 mK, with no discernible difference between the two.

The example of the mixer part 17 mentioned above is the optical fiber 4
-22 is vibrated, but the present invention is not limited to this, but may take other arrangements that satisfy the basic configuration of temporally changing the light beam propagating through the side optical path.

FIG. 7 (1) shows a second embodiment of the mixing part of the present invention. Parallel flat Zarasu 100 rotating and vibrating in the direction of arrow 101 within the range of angle r.
By using , the mutually true rays ^ and B of the modulated output waveform emitted from the semiconductor ray 118 are set at an emission angle of -1' from the secondary light source 18' which is optically conjugate with the light emitting point of the semiconductor ray 18. It is constructed so that the injection changes over time.

Figures 8(・) and (b) show the parallel plane rMf lath 10 of the previous example.
A corrugated disk 102 that has the same effect as 0's fiK is placed between lenses f19 and 20, and the rotation axis o1 is parallel to the optical axis 0.
Here is an example of rotating around the axis. In any of the above-mentioned embodiments, the emitted light beam at a certain angle is changed by changing the final emitting angle by shaking the light emitted from the main conductor. FIG. 9 shows a diagram in which the light source F18 semiconductor laser is vibrated to change the emission angle θ' with respect to the optical axis OK of the light beam 1 emitted from the radar chip 18 itself at an emission angle θ. It changes the waveform of the light beam emitted from a certain point on the lens surface over time.

That is, the semiconductor laser 18 is connected to the mounting board 110 by the piezoelectric elements lll5. The semiconductor laser 1
8 is configured to rotate and vibrate with respect to the optical axis OK.

In contrast to the embodiment shown in FIG. 1 in which the middle part of the optical fiber was vibrated by the vibrator 41, in the first o l14(s) (b), the incident end part 22- of the optical fiber z4-22 was vibrated, and the light beam was The light beams are mixed by changing the angle of incidence on the optical fiber.

Also, a part of the mixer does not necessarily need to be placed inside the optical distance needle, and as shown in FIG.
In front of 7, parallel plate plus 100 is connected to piezoelectric element 1
11., 111b to the housing 200 of the light wave distance needle, and the piezoelectric element on the other hand generates oscillations with different oscillation phases.
42. Apply an alternating current from 42' to vibrate it, and rotate the parallel plane sarame 100 around the optical axis 0 and the perpendicular axis to move the ray m in parallel after exiting the objective lens. By changing the incident position of the reflected light beam n from a reflector (not shown) on the objective lens, and considering one distance measurement optical path, the light beams with different waveforms are
It is possible to have substantially the same effect as propagating that constant strategy at a time of 1%.

Furthermore, the objective lens that sends the distance measuring light beam m toward the reflector placed at the distance measuring point need not necessarily be a refracting light beam as in each of the above embodiments, but a Cassegrain type as shown in FIG. An objective optical system 300 consisting of a reflective optical system of
(As shown in the figure, the Okuken kissing means combines a blower 301 and a heater 302 to actively create air fluctuations @'303, and uses these air fluctuations to generate distance measuring light -m. Alternatively, the emission angle or incidence angle of the reflected light 111n may be changed.

[Brief explanation of drawings]

FIG. 1 shows a light wave design showing a first embodiment of the present invention. Lock diagram, Figure 2 (・) (b) (C) is a photograph showing the waveform of the light beam depending on the emission angle of the semiconductor laser, Figure 5 (・)
(b) (e) is an optical layout diagram schematically showing the action of the mixer part of the present invention, FIG. 4 is a waveform diagram showing the action of the mixer part,
Figure 5 is a photograph showing an example of the waveform after mixing, Figure 6 is a diagram showing the dispersion of distance measurement data to show the effect of the present invention on distance measurement, and IA7 diagram (m > 10) is a photograph of the 11E2 of the present invention. FIG. 8(a)(b) is a diagram showing an embodiment of ts3 of the present invention, FIG. 9 is a diagram showing a fourth embodiment of the present invention, FIG. 10(a) (b) ) is a diagram showing a fifth embodiment of the invention, FIG. 11 is a diagram showing a sixth embodiment of the invention, and FIG. 12 is a diagram showing a seventh embodiment of the invention. 11... Oscillator, 18... Semiconductor laser, 17...
・Gikina part, 27... Objective lens, 41... Vibrator, 22... Optical fiber arm-0 second
Figure (a) (c) <bl) Figure 5 ((1) Figure 9 (b) Figure 10 - 445 = Figure 11 L Figure 12

Claims (1)

[Scope of Claims] (1) A step of emitting a distance measuring light beam from a light emitting source driven at a predetermined nine modulation frequencies, and a step of transmitting the distance measuring light beam to a point to be measured by an optical means, a step of receiving a reflected light beam from the distance measuring ft line reflected from the vaginal fluid distance measuring point; measuring a phase difference between the reflected ft,@ and the distance measuring light beam;
In a light wave ranging method that measures the distance to a point to be measured based on the phase difference, in order to eliminate the influence of the ranging light rays that are inevitably generated from the light source and have different waveforms, A light wave measurement system characterized in that at least one of the plurality of distance measurement light beams is propagated in a distance measurement optical path formed by the distance measurement light beam and the reflected light beam at a different time from that of the other distance measurement light beams. Distance method. (2) At least one of the plurality of distance-measuring light beams is emitted from a certain point of the optical means at a different time from the distance-measuring light beam of the pond. The light wave distance measurement method described in section. (3) The step of measuring the phase difference further includes the step of measuring the phase difference a plurality of times for one distance measurement point and averaging the plurality of phase difference values, The same kind! The light wave according to claim 1 or @2, wherein the time required to emit the II distance light beam at least twice is shorter than the time required to average the phase difference value. Distance measurement method. (4) a light emitting source that is driven at a predetermined modulation frequency and emits a distance measuring beam; an optical means for transmitting the light beam from the light emitting source to a distance measuring point; and a nuclear distance measuring point. A phase difference measuring means for receiving the reflected light beam from the reflected distance measuring f@ and measuring a phase difference between the distance measuring light beam and the reflected light beam, and a distance from this phase difference to the distance measurement point. A light wave distance measuring device comprising a calculation means for calculating a plurality of distance measuring light beams having different waveforms, which are inevitably generated from the light emitting source, between the distance measuring light beam and the reflected light beam. 1. A light wave distance measuring device comprising a mixing means for causing propagation at different times in a distance measuring optical path that is formed. 151 111. The mixing means is for the plural distance measuring +
Light wave ranging f! according to claim 4, characterized in that at least one of the light beams S is emitted at a certain point of the optical means at a different time from other ranging light beams. 1ta 16) The phase difference measuring means further includes averaging processing means for performing phase difference measurement a plurality of times for one distance measurement point and averaging the plurality of phase difference values, and the optical means The original wave distance measurement according to the scope 1g section 4 or 5 of Patent Yu Seigyu, characterized in that the time required to emit the same type of #ll light beam at least twice is shorter than the average time of the averaging processing means. Fitted fl. (7) The light wave distance measuring device according to any one of claims 4 to 6, wherein the light emitting source is a semiconductor radar.