JPS58180906A - Distance measuring device - Google Patents

Abstract

PURPOSE:To make it possible to detect image displacement, which is effective for distance measuring even though data is few, by performing binary coding of the detected output of received luminous flux with respect to a plurality of reference values, and obtaining the correlation of the two luminous fluxes which have passed spatially different parts. CONSTITUTION:The images of two different luminous fluxes from the same body to be measured, which have passed spatially different parts, are formed through image forming lenses 501 and 502, and mirrors 503, 504, and 505. The light is received and detected by a photoelectric transducer element array 506. Said detected output is binary-coded by a converter circuit 508 with respect to a plurality of reference values such as three sets. The binary coded signals of three sets and the like are processed to obtain correlation by shift register 510 and exclusive OR circuits 541, 542.... Therefore, effective image displacement detection for distance measurement can be performed even though data is relatively few. When the number of the data is many, accuracy of the image displacement detection is increased and the highly accurate distance measurement is performed in comparison with a simple binary coding.

Description

[Detailed description of the invention] The present invention is suitable for one-distance devices such as cameras.

A photoelectric conversion element array is provided near the focal point of the two O coupling optical systems, and the photoelectric conversion output of the first coupling optical system regarding 9 is time-series and taken out as al-aN, and similarly lI2 Tsumugi g
Time-series photoelectric conversion output regarding party ethics of one-dimensional system b
The signals a11...a N/ and bll ・-bNIK are taken out as l-...bN and binarized, and the mutual positions are shifted one by one to obtain L n+ax 1ii
Calculate the amount of mutual correlation regarding the mutual positions of l, and find the position p (1<p(La+ax)) that gives the maximum correlation among the amounts of correlation of L wax ml determined in this way,
A distance column determining device for determining the distance of the subject from
153433 KWIA shown. In this method, the number of data to be compared (N=N-L
For example, if the number of mhx (mh In subsequent data processing, information is insufficient, and it is impossible to obtain displacement detection accuracy that allows one photoelectric conversion element to be divided into several parts.

The present invention solves these drawbacks and provides a distance measuring device that can detect 60 displacements effectively even when the number of comparison data is small, and with high precision when there is a large number of comparison data. With the goal.

Before describing specific examples, we will explain the iris 1 according to stripes 1 to 4.
side signal ml...island, and @! Oitem issue b@-
I will explain how to take the correlation between the two. Figures 1 and 2 are for M(H), and Figures 4 and S are for M■N.

Figure 1 shows N-16, M is 8, and the number of mutual position combinations that are compared by shifting the data one by one is L wax m N
-M + 1 m 9 is illustrated.

The amount of correlation between a1 ~ Hatake - and b1 ~ b・ is C(1)′, and the amount of correlation between Hatake ~ a and b1 ~ b・ is L L+
7 C (calculated as Ll as L W L Wax t, @
Obtain the distribution of correlation amounts as shown in Figure 2. Here, L-L (LP=6 in the figure) giving the maximum correlation represents the relative deviation of the two O-monitors on the photoelectric converter array, and therefore reflects the distance of the detection object.

Figure 3 illustrates a case where @Lmax = 9, a combination of mutual positions in which data is shifted one by one and compared with N■Ml-12. Assuming that the correlation amount between a1~as and bs-bn is C(1), and al~a- and b4~b11
Assuming that the correlation amount is C(2), the correlation amounts up to and<Lmaxx9 shown in the figure are calculated in the same manner to obtain the distribution of correlation amounts as shown in FIG. L-L gives the maximum correlation here.

(L-6 in the figure) represents my deviation amount, and therefore reflects the distance of the protruding object.

Now, as a way to find the correlation, each data is simply converted into 2fl, and the Exe1w of the binarized data of column 1 and column b is mutually
When taking the slma/OR, the correlation amount C (turn) is 11~
aHzbl~b binary signals 11'~aN', b1
'~bM', the following is obtained for the case of FIG.

Here, e is E-wing/1usty fist OR, and pΣ is booted, so it is not algebraic addition but normal addition. Therefore, in this case, if there is a perfect correlation between bl~bM and 8L~'L+M-1, then C(IJs-0), and if there is no correlation, then C(LJ-M). By the way, in reality, when the addition number C (#iy) in the above example when calculating the correlation is a small number such as about 20 or less,
0, which increases the error in determining the accurate correlation position L
In this case, the above-mentioned difficulty is solved by providing a plurality of reference levels in 2I[. To explain the case of Fig. 1 again, it is necessary to find the correlation between bl~bM and 'L-'L+M-1.

and ajK are binarized at the reference level of ya=l, 2-., R-, respectively.
r6. R and correlation calculation C (LIFi) are expressed by the following equation.

By performing a correlation calculation on the MJIKs compared at a plurality of reference levels in this manner, the number of information sounds used increases, making it possible to detect positional deviations with higher accuracy.

#! Figure 5 Fi is an example in the case of iu'x and N as shown in Figure 1. In this figure, there are three standard levels for binarization (
II-w-3) is shown. For the original school, the image of the same part of the object detected by the storage lens 501% and 502 is fixed on the mirror 501m, 504.50 St, L, C, D.

The distance to the object to be detected is measured by detecting the relative position of the two particles of the object on the lj#t11Fi photoelectric element array 506'. A well-known configuration is adopted. Lens 5OI
K's Isso Kigogo 11...Issei Shin by aN and lens 502! bt...bM is determined by charging conversion element array block So@: at = a : bs - bll (
N>M) is time-seriesized and output as 507KjJ.

This signal @ is at the 4iI number 02 value level (R■3 in the figure)
It is binarized by the binarization circuit 50 @ and sequentially outputs 5.
Passed away by 0. Here, an example of a binarization circuit with three binarization levels will be explained with reference to Fig. 6. At 0 o'clock, the signals that are serialized and input are processed by the sump Yagi-Rudoro 01 in Fig. 6 until the next signal is input. held for a period of time. There are three reference voltages that are fixed in advance or can be applied as appropriate depending on the contrast of gI.
60゛2.808.604
The three 2fil signals are compared by the AND gate s
Send to os, sos, 607. AND gate SO5,6
0L @0FFi sequentially receives a pulse that divides the sample-and-hold period by three, so that the three binary signals are time-series and appear sequentially at the output of the OR gate 60-.

In this way, if one side data, for example al, is 31! Binary data of II&s Figure 5O
It is transferred to shift registers 510 and 511 via St. The transfer stage of one of the shift registers 510 and 511 is shown. The shift register 511 is shown as <(N-M)XR (R- in the diagram).
3) transfer stages, and each transfer stage of Rfi has needles (N-M
+1) output terminals 521 to 52F. The shift register 510 has a transfer stage number of MXR+1 or more (in the case of MXR+3 in the figure), the output terminal shown in the M+R+1st stage! 530. As shown in the figure, each of these output terminals is connected to 541 in order to perform 1xeli+siv*OR between each output of s21 to 527 and the output of 530.
~54F Exelusi MA ORK connected. 3
The binarized data regarding the two binarization levels are sequentially 1
512Kml', 513Kml'', 514a
-1515 to 11'-516K a)i” s 51
TKbll-(When it becomes i-like IIVC, O℃x@1w
The outputs of 5ive 0R541 to 54γ show the correlation regarding the third standard level at -H1 in the Koji 1 diagram, and then the first stage transfer proceeds! 612 Kat”,
“l” in 513, $1 4K
al Otori%515Kam"・=51 II #Cbl
', 517 K J"lDjl(7) Ixslwiiv
e The output of OR541 to 547 is 11 in the Tsuru 1 diagram.
It shows the correlation with respect to the second criterion level at 0 o'clock,
One more step of transfer progresses to 512 K II's 51
3K mml, 514 to 8m”) 515Kam”
=S 1 @Kb*”, Ex@1usive OR541~54T output when it becomes 517K kl is the first
In the figure, the correlation related to the third criterion level at -1 is shown. In this way, the progress of transfer and 4KL-1
lex@1w5 corresponding to the position ~(N-M+1')
The correlation values that appear sequentially in the outputs of iv*0R541 to 54F (0 if there is a correlation, l if there is no correlation) are, for example, the 7th
p is accumulated by each accumulation block in FIGS. 701 to 101.

The maximum I[ accumulated is MXR in this case. Cumulative block 701~? (Since the blocks 701 and 701 have similar configurations, the diagram shows only the configuration of one block 701 among them.

In the diagram, the counter-decoder lit↓ is, for example, 1 m with a 4-bit counter and a decoder, and the count number is a pre-selected value of 11 (8<l!4-1, generally q
When it is a bit counter, it is 8<2q-1), and when it is small, it is y wx l! 11110, when the count number is 8, #1y=01 z;l; when p count number is Ii + 1, it is decoded to become y W B m l; 4 Find - is the value of L that gives the minimum count number. Place*L,
Therefore, it is sufficient to count with (8+1)t, which is much smaller than counter #:t(M XR). The counter is cleared just before the accumulation starts, so the output y m
@ m Q and AND gate 812 is enabled. Also, one input 801 of the OR gate 811 is
Calculation control block T so that it becomes 0 until m completion.
110 while the accumulation is in progress.
The output of Ex*1w5i ma/0R541 which inputs 4 and p is as it is\OR gate 811 and AND gate 1112t
- and input to the counter decoder 813.

As the counting progresses in this manner, when the contents of the counter reach (8+1), the 1 output becomes 1 and the AND gate 812 is disabled, so that the contents of the counter are fixed at <S+1) thereafter. In this way, the accumulation progresses, and
After (MXR) transfers are performed from the time when bl enters into 51F, correlation calculation (1lix・1
The s1r@0 illusion and its counting end. At the end of this counting, except for a small number of Kalashita decoders, their 2 outputs and y outputs are 1 (0) Then, the input of 801 in FIG. If the ND gate 812 is not disabled, that is, the counter whose count number is less than 8+1 will increase its count number. Then, the AND combination is calculated. When the count number increases, all 1 outputs become 1, and when p-destination MND coupling is detected, the counter stops counting at this point. At this time, the 7% m outputs of all counter decoders except for one counter decoder are all El), L L
Only the output of the counter decoder at position p is 1aII1
1.1-0. Therefore, the calculation/control block 708 reads the position of X, -t, which is y■O (giving maximum correlation) at this point, and outputs it as a distance signal from TO9. Example 9
Explain with illustrations.

The detection optical system shown in FIG.
s, 1! l1c- In the image forming optical system 901 moving in the direction of the original axis, a microlens array 802 provided near the lens surface 11, and C, C, D, etc. placed behind this microlens. It is composed of a photoelectric conversion element array 803'. Each photoelectric conversion element *jsbj arranged in the form of a pair near the self-surface of each microlens is configured to receive elements coming from the same detection object and passing through different parts of the exit of the detection lens 901. Element row &B...
・&H and element array bl−・・bNoNo By knowing the relative displacement of the original output turn, it is possible to detect the front focus, focus, and rear bin. With such an optical system and the arrangement of the detection elements, the photoelectric element array block sO3
L load al, J, &1, b @ ”・a NN b N
The data is made into a time series in order of O and output to the output 1107. This signal Fi is binarized by the binarization circuit sO@ according to the binarization level (311 in the figure) and is sequentially output 912, $1
3 [3jlwanru. An example of such a binarization circuit will be explained in Section 10). Input the gII signal in the order of al, b1% '1% bt-, sample and hold circuit 1001
is held until the next Eirin signal enters. @
Figure 11 is the timing chart at this time, and 1101
is sampled and held in the circuit 1001 at the timing of the reference/l response and the Eirin signal Fi1102.

Next, create three reference voltages hVlxma, as shown in FIG.
This is compared with the sampled and held voltage by the comparators 1002, 100m, 1004) and the three 2111 signals are obtained by the ND gate 1005% 100B, 1
Send it to 007. These AND gates have one terminal 10
From 10.1011.1012, pulses that divide the sample and hold period by 3 minutes (1103.1104.1 in Fig. 11)
105) After receiving fr, the three binarized symbols are time-series and sent to the output of the 111-order OR gate 1008. This output is taken into the 6-bit shift register 1020 at the rising timing of the signal 1105 in FIG.
They are transferred sequentially at the rising edge of . In this way, when the video data is sequentially divided into two boxes at three levels J1 and taken into the shift register 1020, during the period tl in FIG. so each a11%11”
, ll"%b1", bt", bi" are appearing. Therefore, this is the output terminal! At 112 and 1113, at l and b phoenix appear, respectively. In this way, the output terminal II 12.913 K#'itm (
D9 it: a ml, bl"; at the timing of ta J's kll""b-1aa at the timing of t4
4... al”, klfi 凰;t at the timing of sty
At the timing of I, the binarized data such as al, bi, etc. will appear. These data are shown in Figure 11110.
If the left registers 810 and 1111 proceed antiparallel in FIG. 9 at the timing of each rising edge of 7, the shift registers $110 and 811 will take in and transfer the data during the period of L4 and *IsL in FIG. Transfer will be paused, so 8
Fill primary '1' in 10 shift registers, 'l
",'l",alt,a,sl,,m,,,
The 2full data of 1111 is also sequentially stored in the shift register of b1K, b-1kit's b, l, b,
,b,”-tv Z value data are synchronized with each other)
It will be loaded and transferred.

As shown in Figure 9, l, wax (Lm in Figures 3 and 4)
axm9) shall be correlated with respect to their mutual positions,
Regarding the case where Lmax is an odd number, both shift registers 11o and Itl are s41~942 and 1151~ in the figure.
952 like K Rx (L 1max -1) /
In this example, there are two transfer stages and the greening level is R.
-3χ and R every 921 to 822 and Hiil S 1 to 8
32 (LmaxH)/ji output terminals. Also, at this time, both shift registers ti
The (L wax +1) output terminals from le, 911 are arranged alternately as shown in FIG.
L wax Ez@1wsivm corresponding to the position of x
The OR circuits s g t to s slKtip are continued.

Transfer proceeds to shift registers 1110 and 1111, and transfer R941K ml' is transferred to Jll II 42 K a
x”(I=(Lmax-1)/2) is also the transfer stage!
When 151Kb- is transferred and ff9S2[bl'' is input, the correlation calculation starts i), Ex@1mal MA/OR circuit 861 transfers b1X+□Φ- to 962, 'IJ at
' e b 1 breath is the next Ex@1iislvs OR
Depending on the circuit, b 1” ei3 alt is changed to the next Exe
The alleb 凰 is caused by the luslve OR circuit.
. . .Similarly, the correlation regarding the binarized data based on the first reference level of the sequence corresponding to -1 in Fig. 83 is the Ixalaai MA/OR circuit 11.
61-98TC)'' output.

Next, when the transfer of shift registers 910 and 911 advances by one stage, bsI+1 is generated by the Exeluslve OR circuit 961.
ea- is U” by Kxa1wsiv@OR circuit 962
$b 1"? Similarly, in FIG. 3, the correlation regarding the 2m data based on the second reference level at -1 is Ix@1us1vv OR (BJ path 1161 to 1167
3J is reduced to 0 output. Furthermore, for the next transfer J) K =
The correlation regarding the binary data based on the JI3 reference level at = 1 is determined, and the correlation regarding the binary data based on the @1 reference level at K=2 is cleared by the next transfer... In the same manner, the left register 1110 ．．
According to the transfer of 1111, each correlation is Ex@1u
It appears in the SIM OR circuits 961-981. The number of correlations is counted by a circuit like the one shown in Figure 7 mentioned above, and the position of the maximum correlation is determined.

Figure 13 shows the position of maximum correlation L w 1- L wax
FIG. 12 is a block diagram in the case of not only dividing into L wax pieces but also detecting the fraction thereof.

In this case, the EX (111111ma/0RE) output is inverted and output as shown in FIG. Count the number of cases where there is a correlation. At the end of counting, count data such as C (LJ) in FIG.
−C(L+1)−C(υ calculation is L=L, −1 and L=
Regarding L K, D(L - 1), D(LP) p t - and the fraction ΔX is calculated. Therefore, the amount of displacement is calculated by L = L - 10 x, and as shown in Fig. 13, 1309. Output.

As described in detail above, according to the present invention, distance measurement can be performed effectively even when the number of comparison data is small, and with higher accuracy when there is a large number of comparison data.

[Brief explanation of the drawing]

Figures 81 and 2 are 11,1 and rj71.2 (Diii
Figures 3 and 4 are diagrams illustrating another method of correlation and p for the l19 signal. Figure 5BtJ-Figure 8 is the i@ Fig. 5 is a block diagram showing the steps up to the correlation calculation of the 1st and 2nd &f# signals, Fig. 6 is a circuit diagram showing the binarization circuit of the 1st embodiment, and Fig. 7 shows the correlation. FIG. 8 is a block diagram for detecting the highest correlation 1k from the calculation results; FIG. 8 is a circuit diagram for explaining the evaluation details of the accumulation block; FIGS. Figure 9 is a block diagram corresponding to Fi group 5, Figure 10 is a circuit diagram corresponding to Figure 6, Figure 11 is a timing chart, and Figure 12 is a data transfer state t- of the shift register in the circuit of Figure 10. Diagram to explain,
FIG. 13 is a block diagram corresponding to FIG. 7, FIG. 14 is a diagram explaining signals input to the counter block in FIG. 13, and FIG. 15 is a diagram corresponding to FIG. 4 in this second embodiment. , FIG. 16 is a diagram illustrating a method for more accurately detecting the position where the maximum correlation is obtained from the signals shown in FIG. 15. [Explanation of symbols of main parts] 506.903...Photoelectric element array block 802.
603.604:1002.100&1004...Comparator town, Mamaro, Mabata...&*ttEE L---12 '34567 B 9

Claims (1)

[Claims] A photoelectric conversion element array and means for converting the signal charges thereof into time series are provided near the surface of the light beams emitted from the same detection object and passing through spatially different parts, and both light beams K11
The light emitted by the light beam changes its relative position on the array according to the distance of the detected object.
A distance measuring device characterized by having means for binarizing 111tII signals b1 and -b, which are transmitted from the east K1m, with respect to one reference level.