JPH0367203B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field to which the Invention Pertains) The present invention is directed to a pair of optical sensors each comprising a plurality of optical sensors that receive light incident from an object whose distance is to be measured through different optical paths and generate an image of the object. Light is received by a fixed optical sensor array, and two image data sequences corresponding to the light intensity distribution in the image obtained by quantizing the image output signal from each optical sensor array are mutually shifted and correlated. The present invention relates to a distance measuring device that measures the distance to an object from a shift amount that exhibits a high correlation.

(Prior art and its problems) The above-mentioned type of distance measuring device is a new type of purely electronic distance measuring device that does not have any moving parts, and is popular for its small size, low cost, and high accuracy. It has been attracting attention in recent years. However, this type of distance measuring device was originally developed for automatic focusing of cameras, and the object for which distance measurement is possible is placed in front of the object perpendicular to the plane on which the pair of optical sensors that receive the image are installed. It has the disadvantage that it is possible to measure only when the object is located, and it is not possible to measure the distance to an object in an oblique position.

In other words, when this type of distance measuring device is incorporated into a camera, the subject to be imaged by the camera is usually in front of the camera, and the distance to the subject in front is measured and the camera is focused accordingly. If you want to focus on a subject that is not directly in front of the camera, first point the camera at the subject, measure the distance and focus, and then move the front of the camera to the desired angle. The shutter must be cut at the correct position.

A conventional device of this kind will be explained with reference to FIGS. 1 and 2. Figure 1 shows the measurement principle of a conventional device. In the figure, light emitted by an object 1 whose distance d is to be measured, for example reflected light from sunlight, is placed in an optical instrument, for example a camera, at a base distance b from each other. A pair of small lenses 2, 3 with built-in short focal length f provide two optical paths 4, 5 that are spatially different from each other.
The light enters each of them through the The object 1 has a luminous intensity distribution shown by two chevrons in the figure, and images 7 and 8 of the object having such a luminous intensity distribution are captured by the small lenses 2 and 2.
3 onto their common focal plane 6.
When object 1 is at infinity, the centers of images 7 and 8 are at positions 70 and 80, respectively. When object 1 is at a short distance as shown in the figure, the image center is x1 and x1 from positions 70 and 80, respectively.
They come to positions 71 and 81 shifted by x2. Now, if it is possible to measure these deviations x ₁ and x ₂ by some means, the distance d to object 1 can be easily calculated using the formula d=b・f/x where x=x ₁ +x ₂ You can decide.

Optical sensor arrays 10 and 11, schematically shown in the figure, are provided on the focal plane 6 for measuring the amount of deviation. Both sensor arrays each include a plurality of optical sensors, and each receives images 7 and 8 and generates a video signal train according to the light intensity distribution. If these two video signal strings have positions 70 and 80 as their reference positions, and the reference positions of both signal strings are both 0, then
By measuring the amount of mutual deviation between both video signal streams, the amount of deviation x described above can be measured. It is clear from the previous equation that the deviation amounts x1 and x2 in the above equation do not need to be measured separately for distance measurement, and it is sufficient to measure their sum x, so the mutual deviation between the two video signal streams By measuring the quantity x, the distance to the object 1 can be determined.

Since the above-mentioned video signal is an analog quantity, it is digitized using an appropriate quantization means to form a video data string, and then an electronic circuit determines the amount of deviation xn between the video data strings, which is then detected by an optical sensor. The above-mentioned deviation amount x is obtained by multiplying the mutual spacing of . However, the distance signal output by the measuring device is the amount of deviation x
It is not necessarily necessary to use some calculated distance d, and the above-mentioned deviation amount xn between the data strings is often sufficient.

FIG. 2 shows a means for measuring the distance to an obliquely located object using a conventional device, and the obliquely forward object is indicated by 1a in a rectangular shape. The camera with a built-in distance measuring device measures the distance d to this object 1a.
The camera is tilted by an angle θ so that it is in front of it, and after completing the measurement in this state, the camera is turned to face the object 1 shown by the chevron and the shutter is turned off. Second
In the figure, parts corresponding to those in Fig. 1 are labeled with the reference numerals in Fig. 1 and shown in solid lines, and the reference numerals of corresponding parts when tilted diagonally are given the subscript a.
Note that it is marked and shown in dashed lines.

As explained above, the conventional distance measuring devices have the drawback or inconvenience of having to point the front of the device toward the object whose distance is to be measured each time.

(Object of the Invention) The present invention solves the drawbacks and inconveniences of the conventional devices as described above, and even if an object exists in a diagonal direction that is deviated from the front, the device can be moved in the diagonal direction while keeping the device facing the front. An object of the present invention is to provide a distance measuring device that can measure the distance to a certain object.

(Summary of the Invention) According to the present invention, the above object is to provide a pair of optical sensor arrays on which images of an object to be measured are formed through spatially different optical paths, and each optical sensor array of the optical sensor array. a quantization circuit that quantizes a video output signal according to the intensity of light received by the sensor into video data; a register circuit that stores the video data quantized by the quantization circuit as a video data string corresponding to each video; Based on both video data strings of the register circuit, evaluation function data indicating the degree of correlation for a plurality of combinations of both video data strings having different relative positions with respect to a reference position on the pair of optical sensor arrays is generated. an evaluation function generating circuit that performs the evaluation function generating circuit; and a deviation amount detection means that detects the deviation amount of the image from the reference position based on a combination of the two image data strings in which the evaluation function data of the evaluation function generation circuit shows the maximum correlation number. In the distance measuring device, the amount of deviation corresponds to the distance to the object, the evaluation function generating circuit has a plurality of reference positions set according to the direction of the object to be measured, and the evaluation function generating circuit is configured to set a plurality of reference positions according to the direction of the object to be measured, The evaluation function data is generated for each of the plurality of reference positions, and the deviation amount detection means detects the deviation amount of the image from each of the plurality of reference positions. .

(Embodiments of the invention) Examples of the invention will be described in detail below with reference to the drawings. FIG. 3 is an explanatory diagram of the operating principle of the apparatus of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. Photosensor array 10, 1 in FIG.
1 is made longer in the horizontal direction of the figure than in the case of conventional devices, and the target 1 can be viewed from a short distance diagonally left and right.
Even if the light emitted by
This has been taken into consideration to ensure that it does not extend beyond the scope of the Although lenses 2 and 3 are depicted as two separate lenses in the figure, they may be used in different locations on one lens, as in the case of a single-lens reflex camera; in this sense, lenses 2, 3 3
may be part of the lens.

Figure a shows the case where the object 1 is located in front perpendicular to the focal plane 6 where the optical sensor array is provided, as in Figure 1, and in this case, the object 1 of the images 7 and 8 is at infinity, as in the conventional case. The distance d to the object can be measured by measuring the sum x of the deviation amounts x1 and x2 from the position of the image indicated by the chain line when the object is located at the position of the image indicated by the chain line. Figure 2b shows object 1b (object 1 in figure a).
) is located forward in the diagonal angle θ direction to the right. In Figure b, the center position of the image 7 shown by the chain line by the lens 2 when the object 1b is at infinity is I1, and the image 7 when the object 1b is at the short distance shown in the figure is I1.
Let the center position be I, and let the amount of deviation between them be x1. Also, set the optical axis center points of lenses 2 and 3 to L2 and L3.
The intersection of the line with base width b connecting both points L2 and L3 and the future optical path when object 1b is at infinity (drawn as a line indicating distance d in the figure) is as shown in the figure. Let point B be the distance between point L2 and point B, b1, and distance between point L3 and point B be b2.
(b1 and b2 are generally different). Target 1b
If the center position of is represented by O, the triangle O, B, L2
From the similarity relationship between and triangles L2, I1, and I, x1/b1=21. Since the focal length of the lens L ₂ is f, the length of the line segment 21 is f/cos θ, and when this is substituted, x1=b1·f/d cos θ is established. Regarding the left lens 3 side, if the deviation from the center of the image when the object 1b at the center of the image 8 is at infinity is xθ as shown in the figure, x2=b2・f/d cosθ When added together, b=b1+b2, so x=b・f/d cosθ where x=x1+
x2, and the distance d can be obtained from d=b·f/x cosθ.

FIG. 3C shows a case where the object 1c is diagonally forward to the left, and similarly to FIG. , 8 center I deviations are x1 and x2, respectively
Then, the exact same relationship as in the previous equation is established, and the distance d can be found from the mutual shift amount x of the images.

As can be seen from the above explanation and formula, when measuring the distance, it is not necessary to separately measure the deviations x1 and x2 of images 7 and 8 from the reference points I1 and I2; it is only necessary to know the sum x. is sufficient. Therefore, if the position I1 in the optical sensor array 10 and the position I2 in the optical sensor array 11 are superimposed as corresponding reference points, the images 7 and 8 will move in opposite directions as the object approaches. Because it shifts to
By measuring the amount of deviation between the images 7 and 8, the amount of deviation x described above can be measured.

FIG. 4 shows an embodiment of the present invention, which is constructed based on the above principle. At the top of this figure, there is shown a photosensor array section 100 consisting of left and right photosensor arrays 100L and 100R, which are schematically indicated by 10 and 11 in FIG. Receive light. These optical sensor arrays 100L and 100R generally consist of mutually different numbers of optical sensors, in this example q and p optical sensors, respectively (where q>p). Furthermore, in this embodiment, the right photosensor array 10
0R is when the object to be measured is in front of you.
The optical system is configured so that the image is received at the center regardless of the distance to the object. On the other hand, the left optical sensor array 100L
In this case, even if the object is directly in front of you, the image is shifted to the left as the object approaches. When the object is diagonally in front of the right, the reference position of the image for the object at infinity shifts to the left compared to the reference position of the image for the object in front of the left and right optical sensor arrays, and as the object approaches, the image shifts to the reference position. The photosensor array 100L on the left side is shifted to the left, and the photosensor array on the right side is shifted to the right. When the object is diagonally to the front left, the reference position for the object at infinity shifts to the right than the reference position of the image for the object in front for both the left and right optical sensor arrays, and as the object approaches, the image shifts to the left from the reference position. The photosensor array 100L on the right side is shifted to the left, and the photosensor array on the right side is shifted to the right.

Each of the optical sensors in the optical sensor arrays 100L and 100R emits a video output signal corresponding to the amount of light received by each optical sensor according to the light intensity distribution of the image. The image data is quantized into digital value video data for each optical sensor by the groups 200L and 200R. Quantized video data may be simple 1-bit data or may consist of multiple bits. In any case, ADC200L,
The video data string outputted by the optical sensor array 200R has a distribution representing the light intensity distribution of the video images received by the optical sensor arrays 100L and 100R. In addition, in the figure, each
For convenience, numbers starting from the left are added as data numbers within the ADC frame.

In this embodiment, distance measurement units 500L, 500C, and 500R are provided individually to measure distances to objects diagonally to the left, in front, and in front to the right, and distances to multiple objects can be measured simultaneously. It is configured as follows. These distance measuring units 500L, 500C, 50
0R is indicated by a dashed-dotted line frame in the figure, in which the distance measuring unit 5 for the object diagonally in front of the right is shown.
The detailed internal circuit for 00R is shown. The other distance measuring units 500L, 500C are constructed in a similar manner.

At the top of the frame indicating the distance measuring unit 500R, in this embodiment, the number of stages n, which are different from each other, is displayed.
Left and right shift registers 400L and 400R with m (n>m) are shown, and input and store video data strings from the left and right ADC groups 200L and 200R. In this embodiment, the input from the ADC to the shift registers 400L and 400R uses a parallel input method using fixed wiring, thereby reducing the data transfer time and therefore the distance measurement time. The shift register 400L on the left of the distance measuring unit 500R for this right object is sent from the ADC group 200L on the left to its first shift register 400L.
N pieces of video data starting from the 1st one are supplied through fixed wiring, and m pieces of video data starting from the 1st one from the right ADC group 200R are supplied to the right shift register 400R. On the other hand, in the left shift register 400L in the distance measuring unit 500C for the object in front, two pieces of video data starting from the third one from the left ADC group 200L are connected to the fixed wiring indicated by LC in the figure. and its right shift register 400R
m pieces of video data starting from the third ADC group 200R on the right are supplied through fixed wiring indicated by RC in the figure. Furthermore, the left and right shift registers 400L and 400R of the distance measurement unit 100L for the left object are similarly fixedly wired with n and m pieces of video data starting from the fifth one from the left and right ADC groups 200L and 200R, respectively.
Supplied by LL, RL.

By the way, in this embodiment, the n and m final video data starting from the fifth mentioned above are configured to match the q and p-th video data, respectively, so q=n+4 and p=m+4. It's summery. More generally, let σ be any integer and q
= n+2σ, p=m+2σ, and this σ means the number of sensors by which the image shifts when the distance measurement target deviates to the left or right from the front. Alternatively, by selecting σ, it is possible to specify the angle of deviation from the front of the object whose distance is to be measured. From the above explanation, the shift registers 400L and 400R of the distance measuring unit 500C for the object in front include the optical sensor array 100.
The distance measuring units 500L and 500R, which are supplied with image data from the center of the sensors L and 100R, are equipped with an optical sensor array 100.
It is possible to supply video data that is shifted by σ optical sensors to the right and left from the center of L and 100R, respectively, and by selecting the number σ, you can specify the angle of deviation from the front of the distance measurement target. I know what I can do.

Of course, this number σ is not the same for the left and right directions, but different numbers can be selected for the left and right directions. Further, in this embodiment, video data is supplied to the shift registers 400L and 400R using a parallel input method, but a serial input method may also be used. In the case of a serial input method, for example, the optical sensor arrays 100L and 100R are each provided with separate or common CCD devices, and two or one ADC is provided as a quantization means, and the quantized video data is Distance measuring unit 5
00L, 500C, and 500R, each shift register 400 is set so that the number of shifts between them is σ.
It is sufficient to supply it to L,400R. In this case, it takes some time to transfer the video data, but it is often sufficient depending on the purpose.

Now, as described above, the shift register 400 is
The left and right video data strings stored in L and 400R are stored in the evaluation function generation circuit group 60i (i=0 to
The mutual correlation is determined by m−n). The number of stages m of the right shift register 400R means the spread of the image for which the correlation between the image data is to be taken.In other words, the light intensity distribution in the image of the object to be distance measured is calculated using m pieces of image data. To make them representative, a number of 10 or more to several dozen is usually selected. Further, in this embodiment, the right shift register 400R is configured so that output can also be made from the first stage at the left end. On the other hand, the register on the left is configured to enable parallel output starting from the first stage at the left end to the sixth stage, and is connected to the evaluation function generating circuit group 60i described above.
(i=1 to n-m) each receives one of these parallel outputs at one input terminal as shown in the figure, and receives one of the parallel outputs from the first stage of the aforementioned shift register at the other input terminal. connected to receive output in common.

In generating the evaluation function, shift pulses P40, P40 synchronized with each other are applied to the right-most stages of the left and right shift registers 400L, 400R by a central control circuit 900 shown at the bottom of the figure. By this shift pulse P40, the video data stored in the left and right shift registers 400L and 400R is simultaneously shifted from the right side to the left side in the figure. Now, each evaluation generation circuit 60i
(i=0~nm) is the exclusive nor gate 61 and the or gate 62 as shown in FIG.
and a counter 65, and the input terminals 611 and 61 of the exclusive NOR gate 61,
One of the gates 612 receives the video data from the left shift register 400L, and the other receives the video data from the right shift register 400R, and outputs "1" only when the two match.
2 and adds 1 to the counter 65. This operation is performed by repeatedly applying the shift pulse P40.
This continues until the mth video data originally stored in the rightmost stage of the right shift register 400R is output from the leftmost stage,
Therefore, after the shift pulse P40 has been applied m times, the counter 65 of each evaluation function generating circuit stores as a count the number of times the left and right video data received by the circuit match. Generation of the evaluation function ends with these m times of shift pulses P40.

Now, nm+1 evaluation function generation circuits 60i
If we pay attention to the leftmost evaluation function generation circuit 600 among (i=0 to nm), at the time when the first shift pulse P40 is issued, this circuit generates the first video data from the left shift register 400L. , the first video data is also received from the right shift register 400R, and the second shift pulse P40 is
At the time of occurrence, the left and right shift registers 400L,
The same second video data is received from 400R, and this continues until the final m-th video data is received. In other words, the evaluation function generation circuit 600
does not shift the left and right video data columns relative to each other,
In other words, the correlation is obtained in a state where the number of shifts is 0, and this is expressed by the number 0 in the frame showing the circuit. However, the adjacent evaluation function generation circuit 601 receives the second video data from the left shift register 400L at the time of the first shift pulse P40, and transfers the second video data from the left shift register 400L to the right shift register 400R.
The first video data is received from. moreover,
At the time when the next shift pulse P40 is applied, the third image is received from the left shift register 400L and the second image is received from the right shift register 400R. , right shift register 400
Video data that is one step ahead of the video data from R is always received. From now on, the evaluation function generation circuit 60
1, it can be seen that the left and right video data strings are correlated with a shift number of 1. Thereafter, in the same manner, the number of shifts increases by one, and the last evaluation function generation circuit generates and stores a matching circuit for video data as an evaluation function indicating the correlation between left and right video data when the number of shifts is nm. I understand that.

In addition, in the above explanation, the simplest example of the number of video matches between the left and right video data strings was shown as the evaluation function, but the logical function is not limited to the above-mentioned exclusive NOR, but also the correlation between both data strings. Any other known logical function useful for representing can be used. In particular, when the video data is multi-bit, if the shift registers 400L and 400R are configured in a multiplexed configuration and the logic gates of the evaluation function generation circuit are made to correspond to this, a more accurate logic function can be obtained for correlation. can be used. Furthermore, in this embodiment, a means for simultaneously generating evaluation functions for all shift numbers for which correlations between video data strings are to be taken is shown as the best example;
Of course, for applications where the distance measurement may be somewhat long or long, known means for successively generating evaluation functions for each number of shifts may be employed.

As described above, each counter 65 of n-m+1 evaluation function generation circuits 60i (i=0 to n-m)
Inside, the left and right video data columns are respectively 0 to n-.
Since the results of correlations obtained by shifting m steps are stored, it is necessary to find among them the one showing the highest correlation, especially the highest function, in order to measure the distance. This corresponds to each evaluation function generation circuit 60i.
This is performed by simultaneously applying a read pulse P60 to the OR gates 62 within (i=0 to nm). Each time this read pulse P60 is applied, the OR gate 62 is opened and each counter 6
1 is added to 5 all at once. Read pulse P6
When 0 is repeatedly given, the counter 65 that has stored the maximum count value, for example, the shift number i shown in the figure,
The counter of the evaluation function generating circuit 60i corresponding to 1 overflows and outputs a carry signal, for example, a logical value "1". Shift register 7 shown
10 is each evaluation function generation circuit 60i (i=0 to n
-m), and is configured to enable parallel writing from the evaluation function generation circuit, so that the carry signal "1" is input immediately and "1" is stored in the corresponding stage as shown. On the other hand, the OR gate 720 shown on the right is the evaluation function generation circuit 60.
Since the carry signal outputs from i (i=0 to nm) are input in parallel, when even one carry signal is generated, the gate is immediately opened and the central control circuit 900 is notified of this fact. central control circuit 9
00 immediately stops sending out the above-mentioned read pulse P60 based on this notification, so each counter 65 stops advancing and no carry signal other than the above is generated. As a result of the above, only the stage of the shift register 710 corresponding to the counter 65 that has stored the highest count value stores a predetermined logical value, for example, 1.

The above-mentioned shift number i, in which the highest correlation between the left and right video data strings was observed, is read out using the shift register 71.
Central control circuit 900 reads pulse P70 to 0.
It is done by giving from. In this embodiment, the distance signal calculation circuit 800 is configured as the simplest counter, which is merely an example, and is synchronized with the above-mentioned shift register 710 from the time when the read pulse P70 is applied from the central control circuit 900 to the shift register 710. A count pulse P80 is repeatedly applied. Therefore, the read pulse P
70, the data in the shift register 710 becomes 1.
The count value of the counter 800 increments by 1 in synchronization with the stage being shifted to the right in the figure. However, at the same time that the logic value "1" that stores the shift number i is output from the shift register 710, the central control circuit 900 detects this and
Since the count pulse P80 is immediately stopped,
Counting is also stopped and the aforementioned shift number i is stored in the counter 800 as a count value.

An external device 1000 shown in the lower part of the figure is a circuit of an external device such as an optical instrument in which the distance measuring device according to the present invention is incorporated, and in particular a microcomputer circuit incorporated in these external devices, and is connected to each distance measuring unit 500L, 500C. ,500R
A control signal CS is issued to the central control circuit 900 in the central control circuit 900, which instructs the central control circuit 900 to read the distance signal, designates the unit to measure the distance, and instructs the central control circuit 900 to measure the distance.
00, for example, receives a distance signal read command and causes the distance signal calculation circuit 800 to send out a distance signal.
Note that the distance signal calculation circuit 800 is not only configured as a simple shift number counter as described above, but also calculates the distance d to the target based on the above-mentioned formula from this count value, and uses this as the distance. It can also be configured to be sent out as a signal. Moreover, the central control circuit 900 can be provided as a common central control circuit for all the units without being incorporated into each of the distance measuring units 500L, 500C, and 500R, and when the external device 1000 is a microcomputer, This function can also be assigned to this function.

FIG. 6 shows a different embodiment of the invention, in which the same parts as in the previous embodiment are given the same reference numerals. In this embodiment, the distance measuring unit 5
00 is configured as a common unit that can be switched and used to measure distances to objects in three directions: diagonally left, front, and diagonally right. The switching circuit 440 schematically shown on the left side of the figure is connected to the external device 1000.
This is an electronic circuit that receives a switching command SS from the switch and gives a signal "1" to only one of the three selection lines 44L, 44C, and 44R shown above, which is selected by the command SS. .

On the other hand, the left shift register for storing image data in this embodiment is the optical sensor array 100.
A front-stage shift register 410L on the left inputs and stores video data 1 to q obtained by quantizing the video signal sequence from ADC group 200L in parallel, and receives video data that will be shifted and outputs the video data from each stage. The left shift register 420L outputs data in parallel, and the right shift register 410R similarly receives and stores left shift registers 420L and 420L that input and store images representing images received by the optical sensor array 100R in parallel. It consists only of a portion corresponding to the front stage part of the register, and no particular rear stage part is provided. The left rear-stage shift register 420L has a number of stages s for the number of mutual shifts 0 to s of s+1 left and right video data correlated by the evaluation function generation circuits 600 to 60s, which is the same as in the previous embodiment. Corresponds to nm.

Now, the aforementioned switching circuit 440 selects the selection line 44R to select the distance measurement to the object diagonally to the front right.
If a signal “1” is output to the AND gate 43LR that receives the video data output from the first stage of the left front shift register 410L
and an AND gate 4 that receives video data from the first stage of the right shift register 410R.
"1" is given to one input of each of 3R. Therefore, when video data is output from each first stage, both AND gates 43LR and 4 are output depending on the logic state of the data "1" or "0".
3RR opens and closes, and the rear or gate 4
3,43R, from the left front shift register 410L to the rear shift register 420L,
Video data is transmitted from the right shift register 410R to evaluation function generation circuits 600 to 60s, respectively. Of course, at this time, and gate 43
LC, 43LL, 43RC, and 43RL are never opened because one of their inputs is always "0". That is, when a signal "1" is applied to the selection line 44R, video data is output only from the first stage of the left pre-stage shift register 410L and the right shift register 410R. of course,
When the switching circuit 440 outputs signal 1 to the selection line 44C that selects distance measurement to the object in front or the selection line 44L that selects distance measurement to the object diagonally to the left, the left pre-stage shift register 4
10L and the right shift register 410R are:
As shown in the figure, video data is output only from the third or fifth stage, respectively.

Assuming that distance measurement of an object diagonally to the left is selected, when generating the evaluation function, first a shift pulse P is sent from the central control circuit 900 to the rightmost stage of the left front shift register 410L.
40 is issued. As a result, the video data in the first stage shift register 410L is transferred to the second stage shift register 420L by sequentially opening the AND gate 43LR and the OR gate 43L. 1 originally stored in the first stage of the previous shift register 410L
When the second video data reaches the first stage of the rear shift register 420L as shown in the figure, a shift pulse P40 synchronized with the shift pulse P40 described above is sent from the rightmost stage central control circuit 900 of the right shift register 410R. is given. Hereinafter, as explained in the previous embodiment, m shift pulses P40 and P41 are given, and the evaluation function generation circuits 600 to 60s simultaneously generate evaluation functions corresponding to the shift numbers 0 to s, respectively. . When distance measurement of the object in front or diagonally to the right is selected, the operation is the same as described above, and the left front shift register 410L and the right shift register 410R are transferred to the rear shift register 420L and the evaluation function generation circuit 600, respectively. ~
The only difference from the above is that the video data string given in 600s starts from the third or fifth video data from the beginning.

Since the circuit operation after the evaluation function is generated is the same as in the previous embodiment, the explanation will be omitted to avoid duplication. As described above, according to the embodiment shown in FIG. 6, by simply adding the switching circuit 440 and the attached gates to the distance measuring unit 500, one distance measuring unit can be set to the front, diagonally left front,
It can be commonly used to measure distances to objects in three directions diagonally to the front right.

FIG. 7 shows yet another embodiment of the present invention, in which the same parts as in the embodiment shown in FIG. 5 are given the same reference numerals. This embodiment also shows an embodiment in which the distance measuring unit 500 is commonly used to measure distances to objects in three directions.
Unlike the figure, the distance measurement direction selection signal SS from the external device 1000 is given to the central control circuit 900. Further, in this embodiment, the optical sensor arrays 100L and 100R are composed of q optical sensors that are equal to each other, and the left and right shift registers that store the video data strings from these are the front-stage shift registers 410L and 410R, and the rear-stage shift registers 420L, respectively. ,4
This embodiment differs from the previous embodiment in that 20R is provided.

First, to facilitate understanding, the operation of the evaluation function generation circuit will be explained. The numbers in the frames of the rear shift registers 420L and 420R in the diagram indicate that the first video data of the video data string originally stored in the front shift registers 410L and 410R is transferred to the rear shift register 420 by the shift pulse P40.
This shows the state when the first stage of L and 420R is reached. Evaluation function generation circuit 600 on the left
In this state, the left rear shift register 42
The fifth video data that is entering 0L and the first video data in the right rear shift register 420R are input. In other words, the circuit 600
inputs, for example, the j-th video data in the right video data string and the j+4th video data in the left video data string. On the other hand, in this state, the next evaluation function generation circuit 601 is inputting the fourth video data from the left rear shift register and the first video data from the right rear shift register. j of the video data string on the right
It can be seen that when the th video data is being input, the j+3 th video data is being input from the left video data string. Furthermore, paying attention to the rightmost evaluation function generation circuit 60s, when inputting the j-th video data from the left rear shift register 420L, contrary to the evaluation function generation circuit 600 described above, the right rear shift register 60s It can be seen that the j+4th video data is input from the register 420R. Therefore, these evaluation function generation circuits generate evaluation functions each having a different number of shifts, as in the previous two embodiments. Now,
It is easy to configure the optical system that forms images of the target on the optical sensor arrays 100L and 100R so that the leftmost evaluation function generation circuit 600 correlates the left and right image data strings with a shift number of 0. In this embodiment, the optical system is configured in this way. The evaluation function generation circuit 600 has a shift number of 0.
Therefore, each of the circuits 600 to 600s generates an evaluation function corresponding to s+1 shift numbers 0 to s as shown in the figure.

Now, when measuring the distance to the object diagonally to the front right, just before the video data is shifted to the subsequent shift registers 420L and 420R in the state shown in the figure, the fifth
The illustrated reset pulse P61 is applied to the illustrated counters 65 all at once by the central control circuit 900 to start counting from the illustrated state. External circuit 1000 selects and commands distance measurement of the object in front
When given to the central control circuit 900 by SS,
In response to this, the central control circuit 900 transfers the σ+1st video data to the subsequent shift registers 420L and 42.
Immediately before reaching the first stage marked with the number 1 in 0R, the reset pulse P61 is given to the counters 65 of the evaluation function generation circuits 600 to 600s all at once in the same way as described above, and the evaluation function is generated from the σ+1st video data. generate. Assuming that σ is 2 as in the previous two embodiments, the reset pulse P61 is given so that the evaluation function is generated from the third video data. When a command is given to measure the distance to an object diagonally to the left, the central control circuit 9
00 is 2σ + 1st video data, and in the same case as the previous example, the evaluation function generation circuit 600 to 600 seconds is generated so that the evaluation function is generated from the 5th video data.
A reset pulse P61 is applied all at once. As explained above, in this embodiment, the external device 1
The advantage is that the direction in which the distance to the object should be measured can be easily switched by simply adjusting the timing at which the central control circuit 900 issues the reset pulse P61 to the evaluation function generation circuit group in response to the selection command SS from 000. There is. Furthermore, as will be easily understood, even if the diagonal angle at which the distance should be measured is not fixed in advance,
It has the advantage that the angle can be adjusted very easily by changing the timing of applying the reset pulse.

In the description of the above three embodiments, the left and right shift registers that store video data strings do not necessarily have to be registers that can shift video data; Testing the correlation between left and right video data streams for various shift numbers using known means is something that can be easily carried out by the applicant within the scope of the present invention, and in this sense, the above-mentioned The description should be understood as illustrating the best embodiment with short distance measurement time.

(Effects of the Invention) As explained above, according to the present invention, the evaluation function generation circuit has a plurality of reference positions set according to the direction of the object to be measured, and generates evaluation function data for the plurality of reference positions. The deviation amount detection means detects the deviation amount of the image from each of the plurality of reference positions, and the deviation amount corresponds to the distance to the target. Therefore, by setting the reference position not only in the front but also in the diagonal direction, it is possible to measure the distance to the object in the diagonal direction while keeping the device facing the front.

Therefore, there is no need to point the device at an oblique direction each time, making it possible to significantly shorten measurement time. Especially when used in a camera's automatic focus device, it is possible to simplify the focusing operation or improve the focusing accuracy. You can improve your performance.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the principle of a photoelectric distance measuring device of the type to which the present invention belongs, Fig. 2 is an explanatory diagram of a means for measuring the distance to an object existing in an oblique direction using a conventional device of this type, and Fig. 3 4 is a diagram illustrating the principle of the device of the present invention, and FIG. 4 and subsequent figures all show embodiments of the present invention, in which FIG. 4 is a circuit diagram of an embodiment in which a distance measurement unit is provided for each distance measurement direction, and FIG. FIG. 4 is a partial circuit diagram showing details of the evaluation function generation circuit in the embodiment circuit, and FIG. 6 is a circuit diagram of a different embodiment of the present invention, which is capable of measuring distances in multiple directions with one distance measurement unit. , and FIG. 7 are circuit diagrams of still another embodiment of the present invention, which is also capable of measuring distances in a plurality of directions with one distance measuring unit. In the figure, 1, 1a, 1b, 1c: object to be measured, 2, 3: camera or lens part that forms an image of the object, 4, 5: mutually spatially different optical paths, 10, 11, 100L. , 100R: Optical sensor array, 200L, 200R: Quantization circuit, 40
0L, 400R, 410L, 410R, 420
L, 420R: Shift register as a register circuit for storing video data string, 43LR, 43
LC, 43LL, 43RR, 43RC, 43RL: AND gate as angular position specifying means, 43L,
43R: OR gate as angular position specifying means,
440: switching circuit as angular position specifying means;
44L, 44C, 44R: Selection line as angular position specifying means, 600 to 600s, 60i (i=0
~nm): Evaluation function generation circuit, 710: Shift register as distance signal generation circuit, 720: OR gate as distance signal generation circuit, 800: Distance signal calculation circuit or counter as distance signal generation circuit, LL, LC , LR, RL, RC, RR: Fixed wiring as angular position specifying means, P61: Reset pulse as angular position specifying means, SS: Selection signal for specifying angular position.

Claims (1)

[Claims] 1 A pair of photosensor arrays on which images of the object to be measured are formed through optical paths that are spatially different from each other, and a video output signal corresponding to the received light intensity of each photosensor of the photosensor array is converted into video data. a quantization circuit that performs quantization; a register circuit that stores the video data quantized by the quantization circuit as a video data string corresponding to each video; An evaluation function generation circuit that generates evaluation function data indicating the degree of correlation for a plurality of combinations of both video data strings having different relative positions with respect to a reference position on a pair of optical sensor arrays, and evaluation of the evaluation function generation circuit. and a deviation amount detection means for detecting the amount of deviation of the image from the reference position based on the combination of the image data strings in which the function data shows the maximum correlation number, and the deviation amount corresponds to the distance to the target. In the distance measuring device, the evaluation function generation circuit has a plurality of reference positions set according to the direction of the object to be measured, generates the evaluation function data for the plurality of reference positions, and generates the evaluation function data for the plurality of reference positions. A distance measuring device characterized in that the amount detecting means detects the amount of deviation of the image from each of the plurality of reference positions.