JPH05215963A - Range finder - Google Patents

Abstract

PURPOSE:To surely prevent the output of the range-finding information of infinity regardless of a fact that an object is at a short distance position. CONSTITUTION:This range-finder is provided with a short distance discriminating means 28 discriminating that the distance of the object is short, by the output from integrating means 24 and 25, and an information selecting means 28 invalidating infinite information by infinity discriminating means 23 and 28 when it is discriminated that the distance of the object is short, by the short distance discriminating means 28, when it is discriminated that object information is short distance information, by the short distance discriminating means 28, the infinite information by the infinity discriminating means 23 and 28 is invalidated as the case the output of the long distance side of a photodetecting means is low because the object is located in the short distance, and the infinity discriminating means 23 and 28 discriminate the infinity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a distance measuring device which receives reflected light from a subject and measures the distance to the subject.

[0002]

2. Description of the Related Art Conventionally, a camera projects light onto a subject,
A so-called active distance measuring device that receives reflected light from the subject and calculates the subject distance based on the principle of triangulation is widely known.

This type of active distance measuring device has the following drawbacks.

When the subject distance is long and the received light level of the reflected light becomes minute, the noise generated from the light receiving sensor and the light receiving circuit becomes a non-negligible level (so-called S / N ratio deteriorates), and as a result, the distance measuring device. Had given an incorrect ranging result.

Therefore, in order to solve the above drawbacks, a distance measuring device using a so-called double integrating circuit as shown in FIG. 1 has been proposed.

FIG. 1 is a diagram showing a schematic configuration of this distance measuring apparatus. In FIG. 1, 10 is a light projecting lens, 11 is a light receiving lens, 12 is an infrared light emitting diode (IRED), and 13 is a semiconductor position. Detector (hereinafter referred to as PSD), 14 is an amplifier connected to its output, 15 is a well-known double integrating circuit,
Reference numeral 16 is an integrating capacitor.

FIG. 2 is a diagram showing an output waveform of the above double integrating circuit 15.

In FIG. 2A, the subject is relatively close and PS
The case where the output current level from D13 is high is shown.

First, a downward integration operation is performed for a predetermined period (fixed) T with the output on the far side (F) side of the PSD 13, and then P
The rising integration operation is performed by the sum output of the long distance side and the short distance (N) side of SD13. Then, the time t at which the increase level due to the sum output returns to the reference value (initial value) corresponds to the distance information.

In FIG. 2B, the object is far and the PSD 13
The output level from is small.

In this case, since the falling level due to the output on the (F) side does not reach Vsmall during the falling integration of the predetermined period T, the microcomputer (not shown) forcibly sets the distance information to infinity. to decide.

As described above, when the subject is far and the S / N ratio is bad, the Vsmall level is set, and when the falling integration amount does not reach this level, the distance information is set to infinity regardless of the time t obtained, and the measurement is performed. The erroneous information from the distance device is ignored to avoid the above-mentioned drawback.

[0013]

However, even such a device still has the following inconveniences.

That is, when the subject is very close, most of the reflected light from the subject is PSD13 due to the principle of triangulation.
Since the light is incident on the (N) side, the output from the (N) side becomes very large, but the output from the (F) side becomes extremely small. Therefore, in this case, the falling integration level at the output on the (F) side does not reach the "Vsmall" level as shown in FIG. I will judge. That is, the worst result is that the distance measurement information indicating infinity is output even if the subject is close.

Next, another problem will be described.

Conventionally, an active type or passive type distance measuring device for measuring a distance in a plurality of areas within a screen is known. Further, a so-called camera with a zoom lens, which can change the focal length of the lens without exchanging the lens, has been commercialized in recent years. Further, various types of cameras combining these, that is, cameras with a zoom lens equipped with a distance measuring device for measuring a plurality of areas within a screen have been proposed and commercialized.

Further, as disclosed in JP-A-60-168111, a distance measuring device for sequentially selecting a predetermined distance measuring area from a plurality of areas on the screen according to the focal length of the zoom lens. There is also.

For example, as shown in FIG. 5, there are five distance measuring areas L on the left and right centering on the central distance measuring area C in the viewfinder frame.
It is assumed that there are 1 to L5 and R1 to R5. At that time, I want to select an appropriate distance measurement area according to the focal length of the shooting lens,
Due to the fact that the distance measurement takes time and the current consumption is large, FIG.
As shown in, in the range of the focal length from a to b, the distance measuring areas C, L1, R1, L3, R3, L5,
When the distance measuring operation is performed by selecting R5 and the focal distance is in the range of b to c, the distance measuring areas C, L1, R1, L
2, R2, L4, R4 are selected to perform the distance measurement operation, and when the focal distance is in the range from c to d, the distance measurement areas C, L1, R1, L3, R3 are selected to perform the distance measurement. It is an operation.

In the distance measuring device having a plurality of distance measuring areas as described above, it is necessary to adjust so that the same distance data is output to the subject having the same distance in all the distance measuring areas. .. However, in order to obtain the distance measurement result for each of these distance measuring areas, it is necessary to change the focal length one by one in the normal mode and adjust all the distance measuring areas. It was annoying. Also, for example, from a to b in the focal length range
In b to c, it seems that C, L1 and R1 in the distance measuring area are sloppy, and the same operation is performed twice or more.

Further, in order to perform the above-mentioned adjustment in the normal mode, various operations such as another photometry operation are included in addition to this distance measurement operation, so that it takes a considerable time to perform one distance measurement. However, there is a problem in that it takes time to average the distance measurement data.

Next, another problem will be described.

As a measurement of the object distance, a so-called active distance measuring device has been known which projects infrared light from the IRED toward the object and receives reflected light from the object to measure the distance. This active type distance measuring device is based on the principle of triangulation, and when a subject is present at 5 m, for example, the position where infrared light is reflected from the subject and imaged on a sensor such as PSD is a specific position. If it is not, the distance cannot be measured. Therefore, the reflection image of the subject of IRED and the adjustment of X, Y and θ directions on the sensor surface (horizontal, vertical and angle adjustment)
is necessary.

Conventionally, in order to perform this adjustment, each PSD and IRED is photographed by an ITV camera through a light projecting and receiving optical system. At this time, the ITV camera is calibrated to a predetermined angle so as to match at a specific distance. And this I
The sensor and IRED imaged by the TV camera are imaged on one monitor screen, and the sensor and IRED (the image of) are matched with the marks such as lines on the monitor screen as targets.
In other words, it was adjusting.

However, in the above-mentioned conventional example, since there is no target on the sensor, it is necessary to make a mark such as a line on the monitor screen for adjustment as described above. There was a problem that the matching state changed depending on the angle and the angle, and accurate adjustment could not be performed.

Further, when there are a plurality of sensors (in the case of a multi-point distance measuring device) and the like, the influence of the angle is likely to occur, and the more peripheral sensors, the more accurate adjustment cannot be performed.

Next, another problem will be described.

Conventionally, a so-called active-type measurement in which the distance of an object is measured by projecting light from a light projecting means such as IRED toward the object and receiving the reflected light to obtain distance data Distance devices are known.

In this type of distance measuring device, a position detection sensor (hereinafter referred to as PSD) is used to receive the reflected light from the subject.
And silicon photocell (hereinafter referred to as SPC)
The one using is also known.

On the other hand, there is also a so-called wide-field distance measuring method, which has a plurality of distance measuring areas, obtains distance measuring data for each of them, and determines which area has the highest probability of being the subject. Are known.

In these distance measuring devices, in order to prevent the measuring circuit from being saturated when measuring a high-luminance object, the size of the distance measuring sensor is reduced as much as possible (the light receiving area is reduced). Therefore, it is necessary to sacrifice the distance measurement accuracy to some extent without suppressing noise to the minimum. As in the former case, when the distance measuring sensor is made small, the spot image of the reflected light protrudes from the distance measuring sensor when the subject is at a short distance, and the distance measuring data is largely displaced. Further, like the latter, unless the noise is suppressed to the minimum, the accuracy of distance measurement deteriorates and it becomes impossible to measure the distance further.

Therefore, the so-called P, which is capable of outputting approximate distance measuring data except for the distance measuring area which requires accuracy, is called P.
An apparatus using a distance measuring sensor based on SD and narrow SPC has also been proposed. By using this method, the influence of high-luminance saturation can be minimized and the short-distance data will not be greatly shifted.

However, even in this type of distance measuring device, it is impossible to obtain accurate distance measuring data, although distance measuring data at a short distance does not greatly shift.

Further, in the wide-field distance measuring system, the total area of the sensor has become larger than that of the normal single-field distance measuring system because the distance measuring sensor is used more for the distance measuring area. .. For this reason, when the subject has high brightness, it is understood that the distance measurement data is out of order to some extent, and noise cannot be reduced to save high brightness saturation, and the distance measurement device has to have poor distance measurement accuracy. I didn't.

A first object of the present invention is to provide a distance measuring device capable of reliably preventing output of infinity distance measuring information even if a subject is at a short distance position. Is.

A second object of the present invention is to provide a distance measuring device capable of adjusting the respective distance measuring data obtained in a plurality of distance measuring areas in a short time.

A third object of the present invention is to provide a distance measuring device capable of accurately adjusting the matching of the light projecting means and the light receiving means to an ideal position and improving the efficiency of the adjusting work. Is to provide.

A fourth object of the present invention is to provide a distance measuring device which is less affected by high-luminance saturation and has high performance, and which can output distance measuring information with less error on the short distance side. ..

[0038]

SUMMARY OF THE INVENTION According to the present invention, a short distance determining means for determining that a subject distance is a short distance based on an output from an integrating means, and a subject distance being a short distance by the short distance determining means. If it is discriminated that the infinity information by the infinity discrimination means is invalid, an information selection means is provided. Since the output on the far side of the light receiving means is small due to the fact that it is located at a short distance, the infinity determination means invalidates the infinite information by the infinity determination means.

A discriminating means for discriminating whether or not a test mode for adjusting the distance measuring data obtained in a plurality of distance measuring areas is instructed, and the discriminating means performs the test mode. If it is determined that the distance measurement operation is performed, distance measurement operation control means for sequentially performing distance measurement operation for each of the plurality of distance measurement areas and sequentially outputting the obtained distance measurement data is provided. A judging means for judging whether or not a test mode for adjusting the distance measuring data obtained in a plurality of distance measuring areas is instructed, and the judging means is in the test mode. Is determined, a distance measuring operation control means for performing the distance measuring operation in the designated distance measuring area and outputting the obtained distance measuring data is provided. Check whether the test mode for adjusting the obtained distance measurement data is instructed. And another discriminating means, Tesutomo at 該判 by means - when it has been determined is de is 1
Adjusting the distance measurement data obtained in a plurality of distance measurement areas by providing distance measurement operation control means for performing the distance measurement operation for one distance measurement area a predetermined number of times and sequentially outputting the obtained distance measurement data. In the test mode for the purpose of performing the above, that is, the adjustment so that the same distance measuring data is output for the same subject in all the distance measuring areas, the normal mode is used.
Unlike the case of the mode, only the operation necessary for this adjustment is sequentially performed for each distance measuring area, or for the designated distance measuring area, or each distance measuring area or is designated a predetermined number of times. This is done for the distance measurement area.

Further, an adjusting mark is provided at a predetermined position of the light receiving means so that the reflected light from the light projecting means from the object located at a predetermined distance is imaged, and the adjusting mark is provided at the position of the adjusting mark.
The position of the light receiving means is adjusted so that the light reflected by the light projecting means from the subject located at a predetermined distance is imaged.

Further, the distance measuring range of the light receiving means for receiving the reflected light from the subject located in the peripheral area is narrower than the distance measuring range of the light receiving means for receiving the reflected light from the subject located in the central area. If the output from the light receiving means for the peripheral area in the screen is data outside the range in which the light receiving means can measure the distance, the light receiving means for the central area in the screen Equipped with arithmetic means for weighting the output data to calculate distance measurement information, the distance-measurable distance on the short distance side of the light receiving means for the peripheral area is made shorter than that of the central area, and When the distance measuring data of the area exceeds the distance measuring range, that is, the distance measuring data of the short distance in which only the light receiving means for the central area can properly measure the distance is output from the peripheral area. In this case, only the distance measuring data from the light receiving means for the central area, or And so as to increase the ratio to be used of.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIG. 3 is a block diagram showing a schematic configuration of the distance measuring device in the first embodiment of the present invention.

In FIG. 3, reference numeral 13 denotes a PSD for receiving light, 2
Reference numeral 0 denotes a switching circuit for switching between two outputs from the (F) side and the (N) side of the PSD 13, which is connected to the output line A (F) according to a control signal from a microcomputer (to be referred to as a microcomputer hereinafter) described later. The switching operation is performed so as to output only the () side or the sum output of the (F) side and the (N) side. Reference numeral 21 is a current-voltage conversion circuit, 22 is a voltage amplification circuit, 23 is a comparison circuit that compares the built-in reference level with the output of the voltage amplification circuit 24 and sends a microcomputer signal, and 24 is a well-known integration circuit of the microcomputer. Double integral operation is performed by control. 25 is a condenser for integration, 12
Is an IRED for projecting light, 26 is a constant current drive circuit for driving the IRED 12, 27 is a resistor for feedback, and 2 is a feedback resistor.
8 is a one-chip microcomputer, and 29 is a switch (SW1) which is turned on by the first stroke of the shutter button of the camera.

Next, the operation of the distance measuring device will be described with reference to the flow chart of FIG.
Explain according to the chart.

First, when the switch SW1 is turned on (step 101), the MUF flag (infinity flag) and the KIF flag (short distance flag) in the microcomputer are set to "0" (step 102). Next, the microcomputer 28 uses PSD1
The switching circuit 20 for switching the output of No. 3 is controlled so that the current of (F) + (N) is output to the output line A (step 103). Then, through the constant current drive circuit 26, IRE
Drive D12 (step 104), which causes PSD
The output of (F) + (N) obtained at 13 is current-voltage converted at the current-voltage conversion circuit 21, and amplified by the voltage amplification circuit 22. Then, the output level of the voltage amplification circuit 22 is compared by the comparison circuit 23 at the next stage (step 10).
5). As a result, if the output level of the voltage amplifier circuit 22 is equal to or higher than a predetermined amount, that is, if the subject is at a short distance, the B output is "H".
At this time, the microcomputer 28 sets the KIF flag to "1".
(Step 106). Also, B output is "L"
In the case of the level, the KIF flag remains "0".

Next, the microcomputer 28 controls the switching circuit 20 so that the output line A outputs NO only on the (F) side of the PSD 13 (step 107). At the same time, the count operation of a timer circuit (not shown) in the microcomputer 28 is started, and the integration circuit 24 is controlled to perform this (F).
The downward integration operation by the side output is started (step 109). Then, it is determined whether or not the count time of the timer circuit exceeds a predetermined time T (step 110). When the count time exceeds the predetermined time T, the downward integration operation is stopped, and the integrated output C at that time is not shown in the microcomputer 28. With A / D converter of
/ D conversion. Then, it is determined whether or not the converted value has reached “Vsmall”, and if not, the above M
UF is set to the "1" level, and conversely, when it has reached "Vsmall", the MUF flag is left at "0".

Next, the microcomputer 28 controls the switching circuit 20 so that the output of (F) + (N) is output to the output line A (step 113). At the same time, the counting operation of the timer circuit in the microcomputer 28 is started (step 114), and the integrating circuit 24 is controlled (F) + (N).
Start rising integration operation by output (Step 1
15). When this rising voltage level returns to the original reference level (C output = 0) (step 116), the counting operation of the timer circuit is stopped and the count time t at this time is calculated (step 117). Distance information TAFD from the count time t to the subject is calculated (step 118).

Next, the microcomputer 28 discriminates the MUF flag (step 119), and if it is "0", unconditionally uses the "TAFD" as information for actually controlling the taking lens (step 121). When the MUF flag is "1", the KIF flag is next determined (step 1
20) When it is "0", the information for actually controlling the taking lens is set to "infinity" (step 122) ,. On the contrary, when the KIF flag is "1", the information for actually controlling the taking lens is set to "TAFD" although the MUF flag is set (step 121).

In the above embodiment, the fact that the subject is close is determined from the output level of the voltage amplifier circuit 22 in the (F) + (N) mode, but the present invention is not limited to this. For example, in the mode of (F) + (N), it is also possible to perform the descending integration operation in the double integration circuit 24 for a predetermined time, and to judge from the level.

According to the first embodiment, when the short distance flag is set even if the infinity flag is set, the taking lens is not driven to "infinity" and the distance calculated by the microcomputer 28 is set. Since the driving is performed based on the information "TAFD", it is possible to avoid the worst situation in which the photographing lens is set to "infinity" even if the subject is close.

(Second Embodiment) FIG. 7 is a block diagram showing the main structure of a camera including a distance measuring device according to a second embodiment of the present invention.

In FIG. 7, reference numeral 31 is an input means for setting a test mode different from the normal mode (this structure will be described later), and 32 is a signal input from the test mode input means 31. A micro that sends a signal to a distance measuring device (to be described later), which also serves as an identification means for distinguishing between a normal mode and a test mode, to perform a distance measuring operation, a distance measuring operation, and a series of camera operations. It is a processor.

Reference numeral 33 denotes a distance measuring device for measuring a distance in a plurality of distance measuring areas, and each distance measuring area C, L1 to 15, R shown in FIG.
The distance measurement of 1 to R5 is performed, and the distance measurement of the distance measurement area as shown in FIG. 6 is performed according to the focal length range. Three
Reference numerals 4, 35, and 36 denote first, second, and third light projecting means arranged in the distance measuring device 33, and 37, 38, 39 denote first and second light projecting means also arranged in the distance measuring device 33. They are second and third light receiving means. Although not shown in the figure, there are provided 8 light emitting means and 8 light receiving means, respectively, that is, the number of the distance measuring areas.

Reference numeral 40 is a focal length detecting means for detecting the focal length of the photographing lens, and 41 is an external signal pin.

Next, the operation at the time of adjusting the distance measuring data in the above structure will be described with reference to FIGS. 5 and 6 using the flowchart of FIG.

The first light projecting / receiving means 34, 37 measures the distance measuring area C, the second light receiving / lighting means 35, 38 measures the distance measuring area L1, and the third light emitting / receiving means 36. , 39
The distance measuring area R1 is measured by the distance measuring area R1, and the distance measuring areas L2, R2, L3, R3, L4, R
4, and L5 and R5 are distance-measured respectively.

First, the microprocessor 32 determines whether the test mode input means 31 indicates the test mode or the normal mode (step 201). If the normal mode is instructed. 6, the focal length detecting means 40 detects the current position of the focal length of the photographing lens. If the focal length is in the range of a to b as shown in FIG. L1, R1, L
3, R3, L5, R5 are selected and the respective light emitting / receiving means are operated to perform the distance measuring operation. If the focal distance is from b to c, the distance measuring areas C, L1, R1, L
2, R2, L4, R4 are selected, the respective light emitting / receiving means are operated to perform the distance measuring operation, and when the focal distance is from c to d, the distance measuring areas C, L1, R1, L
3, R3 is selected, and the light emitting and receiving means are operated to measure the distance (step 202). Then, a series of shooting preparation operations are performed (step 203).

On the other hand, when the test mode is instructed by the test mode input means 31, the first light projecting means 34 is driven to project the infrared light toward the subject (step 204). The reflected light from the subject is received by the first light receiving means 37 (step 205), and the distance measurement of the distance measurement area C is performed based on the result (step 206).
Data to the outside (step 207).

Next, the second light projecting means 35 is driven to project the infrared light toward the subject (step 208), and the second light receiving means 38 receives the reflected light from the subject (step 209). ), The distance measurement of the distance measurement area L1 is performed based on the result (step 210), and the distance measurement data is output to the outside (step 211).

Next, the third light projecting means 36 is driven to project infrared light toward the subject (step 212), and the third light is projected.
The light receiving means 39 receives the reflected light from the subject (step 213), calculates the distance measurement of the distance measuring region R1 based on the result (step 214), and outputs the distance measuring data to the outside (step). 215).

Thereafter, similarly, L2, R2, L3, R
The distance measurement operation of 3, L4, L5 and R5 is performed, and the result is output to the outside.

FIG. 9 is a flowchart showing the operation when a part of FIG. 8 is changed.

When the normal mode is instructed from the test mode input means 31 (step 301), the normal distance measuring operation is performed as described in the above step 202 (step 302, then photographing). A preparatory operation is performed (step 303) and the operation ends.

On the other hand, if the test mode is instructed, the data for specifying the distance measuring area is input from the test mode input means 31 (step 304), and the light projecting means specified by this information is selected. It is driven to project infrared light toward the subject (step 305), the reflected light from the subject is received by the designated light receiving means (step 306), distance measurement calculation is performed (step 307), and the distance measurement data is displayed. Data to the outside (step 308).

FIG. 10 is a flowchart showing another operation when a part of FIG. 8 is changed.

When the normal mode is instructed from the test mode input means 31 (step 401), the normal distance measuring operation is performed as described in the above step 202 (step 402) to prepare for photographing. The operation is performed (step 403) to end the operation.

On the other hand, when the test mode is instructed, the data of the number of times of distance measurement is input from the test mode input means 31 (step 404), and this information corresponds to the predetermined test mode. Performs distance measurement operation (step 40
5) Distance calculation is performed (step 406), and the obtained distance measurement data is output to the outside (step 407). Then, it is determined whether or not the specified number of times of the distance measuring operation has been performed (step 408). If the number of times is equal to or less than the predetermined number of times, the process returns to step 308 again to repeat the distance measuring operation and reach the predetermined number of times. If so, the operation of the test mode ends.

As described above, it is possible to perform more accurate adjustment by repeatedly performing the distance measuring operation a predetermined number of times for one distance measuring area and averaging the obtained distance measuring results.

FIG. 11, FIG. 12 and FIG. 13 are diagrams showing an example of the structure of the test mode input means 31 shown in FIG.

FIG. 11 shows the EE in the test mode input means 31.
This is an example of using an externally readable and writable memory such as a PROM.

Here, in the EEPROM, which is the test mode input means 31, whether or not the test mode is specified, designated area information, the number of distance measuring operations, and the focal length are designated to perform the distance measuring operation ( Information such as driving) is written.

FIG. 12 shows a test mode input for determining whether or not it is a test mode, and information such as designated area information for performing the distance measuring operation, the number of distance measuring operations, and designation (driving) of the focal length by switch input. An example of the case where the means 31 is configured is shown.

Here, information input is discriminated by turning on / off each switch, and an instruction is given to the microprocessor 32.

FIG. 13 shows switches for photographing (switches SW1, SW2, photographing mode) provided from the beginning in the microprocessor 32 for controlling various operations of the camera.
This is an example of the test mode input means 31 having a construction in which a special test mode is formed by combining the above-mentioned various information of the test mode by combining these switches.

The test mode input means 31 shown in FIGS. 11 to 13 may be permanently attached to the camera or may be attached and connected only in the test mode.

Further, in each of the above-mentioned embodiments, the active type distance measuring device has been described, but the present invention is not limited to this, and it has a plurality of distance measuring regions and a region to be measured by a focal length. Even if it is a passive distance measuring device capable of selecting, the same can be provided.

According to the second embodiment, in the distance measuring device capable of switching a plurality of distance measuring regions according to the focal length, the normal mode is set at the time of adjusting the distance measuring data of each distance measuring region.
In addition to the test mode, that is, a test mode for performing only the operations necessary for adjusting the distance measurement data is provided.
Obtain the distance measurement data by sequentially measuring all of the distance measurement areas, measuring the specified distance measurement area, or repeating the same distance measurement area a predetermined number of times. Since the adjustment is performed on the basis of this, it becomes possible to perform this adjustment in a shorter time than in the past.

(Third Embodiment) FIG. 14 is a diagram showing a distance measuring sensor array according to a third embodiment of the present invention.

In FIG. 14, reference numerals 51, 52 and 53 denote PSDs, 54 (54a, 54), which are distance measuring sensors.
b) is a two-divided silicon photocell (hereinafter referred to as SPC) which is also a distance measuring sensor, 61 is a distance measuring sensor array, and 55 is an adjustment mark provided on the SPCs 54a and 54b. is there.

FIG. 15 shows a distance measuring sensor array 6 as described above.
1 is a diagram showing a schematic configuration of a distance measuring device having an image pickup device 1, in which light projected by a light projecting element 62 such as an IRED is used as a subject 6;
5 shows a state of being reflected at 5 and being focused on the distance measuring sensor array 61.

Distance measuring sensor array 61 (actually SPC5
The distance measuring sensor array 61 is adjusted so that the image formed on 4a, 54b) falls within the adjustment mark 55 (range A).

The position and size of the adjustment mark 55 can be calculated by proportional calculation.

First, the focal lengths of the light projecting and receiving lenses 63 and 64 are f _T and f _R , and the image size is "a / f _T = X".
/ L "on the adjustment distance," X / L = A / f _R "to find the position of the image on the distance measuring sensor array 61, and calculate the size and position of the adjustment mark 55. Note that L indicates the distance from the light projecting lens 63 to the subject 65, x indicates the size of the subject, and a indicates the size of the light projecting element 62.

FIG. 16 shows the sensor array 61 for distance measurement after adjustment.
FIG. 6 is a diagram showing a state after the reflection images of the light projecting element 62 and a subject 65 are matched.

FIG. 17 is a diagram showing another example. That is, the adjustment mark 56 is arranged in addition to the 55 adjustment mark, that is, the adjustment marks 56 are also arranged on the PSDs 51 and 53 to improve the adjustment accuracy.

This is because when there are a plurality of distance measuring sensors as in the present embodiment, there is no guarantee that accurate matching will be possible with the peripheral sensors even if matching is performed at the central portion, so adjustment markers are also used in the periphery. By attaching the hook 56, all the sensors can be arranged at ideal positions.

FIG. 18 is a diagram showing another example, in which adjustment marks 57 and 58 are similarly added around the adjustment marks 55 and 56.

This is because even if the size of the received light image changes due to variations in the focal lengths of the light projecting and receiving lenses 63 and 64 and variations in the size of the distance measuring sensor 61 and the light projecting element 62, the center of gravity of the sensor It is configured so that the position does not change. The positions of the adjustment marks 57 and 58 may be obtained by calculating from the standard value of the focal length of the lens, or by displaying the adjustment standard, the positions can be adjusted to ideal positions.

According to the third embodiment, since the adjustment mark is provided on the distance measuring sensor, the IRED is used.
It is possible to accurately adjust the matching of the sensor to the ideal position. Further, there is an effect that the efficiency of adjustment work and the like can be improved.

(Fourth Embodiment) FIG. 19 is a block diagram showing the schematic arrangement of a camera having a distance measuring apparatus according to the fourth embodiment of the present invention.

In FIG. 19, 71 is a left area distance measuring means for measuring the distance of an object in the left area on the screen, and 72 is a central area measuring means for measuring the distance of an object in the central area on the screen. Distance means 73 is a right area distance measuring means for measuring the distance of an object in the right area on the screen. Reference numeral 74 is a microprocessor for controlling these distance measuring means 71 to 73 and calculating distance measuring data for determining and selecting which distance measuring data has a high probability of a subject, and 75 is a microprocessor. The AF lens driving means drives a focus lens (referred to as an AF lens) based on the distance measurement data selected by 74.

FIG. 20 shows the distance measuring means 71 to 7 shown in FIG.
It is a figure for demonstrating each ranging principle of 3 each.

In FIG. 20, reference numeral 76 is a light projecting means such as IRED, which is focused at a predetermined distance by a light projecting lens 77. Reference numeral 78 denotes a light receiving lens that collects the reflected light from the subject and focuses it at a predetermined position, and 79 is a light receiving unit that measures the distance of the subject based on the position of the spot image of the reflected light.

Now, assuming that the subject is at an infinite position,
The reflected light from the subject theoretically forms a spot image from the position of R∞ to R′∞ on the light receiving means 79 via the light receiving lens 78. Further, when the subject is at a distance of R ₅ , a spot image is formed at the position of R ′ ₅ on the light receiving means 79. In the same manner, when there are an object distance of R ₄ is, 'signed a spot image on the _4, subject R ₃ is R' R on the light receiving means ₃ positions, the object of R ₂ is R _'2 At the position of R ₁
The subject is tied spot images to the position of the R _'1.

The spot image thus formed is
An electric signal is taken out as a position change from the light receiving means 79 and converted into distance data.

It should be noted here that as the distance becomes shorter, the light receiving means 79 is extended outward in the direction of the base line (the line connecting the light projecting means 76 and the light receiving means 79 is referred to as the base line). The point is that it is necessary. As a result, the light receiving means 79 must be made quite large in order to measure to a very short distance. If neglected, the spot image of the reflected light from the subject will protrude from the light receiving means 79, and the distance cannot be accurately measured.

FIG. 21 is a view showing the above-mentioned light receiving means 79.

In FIG. 21, reference numeral 81 denotes a light receiving means for measuring an area on the right side of the screen, which is provided in the distance measuring means 73, and 82.
Is a light receiving means provided in the distance measuring means 71 for measuring an area on the left side of the screen. 83, 84, 85 are distance measuring means 79
Is a light-receiving sensor that forms a light-receiving unit that measures the central area of the screen, 83 is a light-receiving sensor that measures the far side of the center, 84 is a light-receiving sensor that measures the middle distance of the center, and 85 is It is a light receiving sensor that measures the short distance side of the central portion.

In FIG. 3, the left-right direction corresponds to the left-right direction (however, the right and left are opposite) when viewed through a viewfinder (not shown), and the up-down (baseline length) direction corresponds to the distance to the object, and The direction is the infinite side, and the downward direction is the close side.

Reference numerals 86, 87 and 88 schematically represent the light projecting means arranged corresponding to the respective light receiving means for measuring the left, right and center areas of the screen.
Reference numeral 91 indicates the spot image of the reflected light of the light projecting means 86, 87, 88 when the subject is at the distance R ₆ (the distance between R ₅ and R in FIG. 20) on each of the light receiving means. It was done.

Here, the light receiving lens (not shown here) is adjusted so as to be focused on the light receiving means at the distance R ₆ .

FIG. 22 shows the distance of each subject (R∞, R ₆ , R) on each light receiving means constructed as shown in FIG.
₅ , R ₄ , R ₃ , R ₂ , R ₁ , R ₀ : the smaller the subscript number indicates the short distance), the spot image on each light receiving means.

Here, since the focus of the spot image is adjusted so that the light receiving lens 78 is fitted at the distance of R ₆ ,
As the distance becomes shorter, the spot image becomes larger as shown in the figure. The spot image of R ₁ corresponding to the distance of L _{1 in} the direction of the base line is the light receiving means 8 for measuring the right and left distance measuring areas.
L, which starts to protrude from 1,82 and is closer than L _{1.
At 0} , most of them are out of the light receiving means 81, 82.

FIG. 23 is a graph showing distance data from the left and right light receiving means 81, 82.

Here, the horizontal axis represents the actual subject distance,
The vertical axis represents the distance data from the light receiving means 81, 82.

As can be seen from this graph, the distance data is output almost linearly from the infinity side to the distance L ₁ , but when the subject comes closer than L ₁ , the distance data deviates from this straight line. In the end, due to the blurring of the spot image, the data at a long distance is output even though the subject is at a short distance. Therefore, the distance data can be used only up to the distance A, and the object distance can be measured only up to L _A. Therefore, as will be described later, when the distance becomes shorter than L _A , the distance measuring data from the light receiving means in the central portion is adopted.

FIG. 24 shows a light receiving means 85 for short distance in the central portion.
It is a graph which shows the distance data from.

Here, L ₀ on the closer side than the distance L ₁
Distance data is output almost linearly up to. Therefore, even if the distance is shorter than L _A , the distance can be accurately measured here.

FIG. 25 is a diagram showing a light receiving means when the light receiving means shown in FIG. 21 is improved.

Here, the light receiving means 81 on the right side is provided with a light receiving means 92 capable of judging whether or not there is reflected light, and this light receiving means 92 is considerably different from the light receiving means 81 capable of accurately measuring the distance. Even though the light receiving area is made smaller by making it thinner, it is possible to measure to the closer distance side.

Similarly, the left light receiving means 82 is provided with a light receiving means 93 capable of determining whether or not there is reflected light. This light receiving means 93 is also considerably different from the light receiving means 82 capable of accurately measuring the distance. It is possible to measure up to a shorter distance while making the light receiving area smaller by making it thinner.

The left and right light receiving means 81 arranged in this way
26 and the output values of the distance data of 92 and 82 and 93.
Shown in.

Here, the distance can be accurately measured up to the distance up to L ₁ as in FIG. 23, but since the light receiving means 93 that can determine whether there is reflected light is installed, the distance can be measured. The distance data returns only up to C, and the object distance L _C can be measured. Then, as in the case described with reference to FIG. 23, when the distance becomes shorter than the distance L _C , the distance measuring data from the light receiving means in the central portion is adopted.

FIG. 27 is a flow chart showing the operation of the distance measuring device of FIG.

First, when a release switch (not shown) is turned on (step 501), the microprocessor 74 issues a command to perform a distance measuring operation. As a result, first, the right area distance measuring means 73 starts the distance measuring operation (step 5
02), the left area distance measuring means 71 then starts the distance measuring operation (step 503), and finally the central area distance measuring means 72.
Starts the distance measuring operation (step 504) and obtains distance measuring data in each area.

Next, it is judged whether or not the distance measuring data in the right area is within the distance measuring range described with reference to FIG. 23 or 24 (step 505). If it is outside the distance measuring range, Next, it is judged whether or not the distance measuring data in the left area is within the distance measuring range (step 506). If it is outside the distance measuring range, the distance data is measured from the central area. (Step 507).

On the other hand, if the distance measuring data in the right area is outside the distance measuring range and the distance measuring data in the left area is within the distance measuring range (step 506), which one of the central area and the left area is the subject is detected. The distance measurement data selection calculation is performed to determine whether the probability is high (step 508), and the distance measurement data is determined based on the calculation result (step 509).

If the distance measuring data in the right area is within the distance measuring range (step 505), the distance measuring data in the left area is detected.
If the data is out of the distance measuring range (step 510), a distance measuring data selection calculation is performed to determine which of the central area and the right area has a high probability of being a subject (step 511).
Distance measurement data is selected based on the calculation result (step 512).

If the distance measuring data in the right area is within the distance measuring range (step 505) and the distance measuring data in the left area is also within the distance measuring range (step 510), the central area is reached. In all areas of the right side area and the left side area, distance measurement data selection calculation is performed which area has a high probability that the subject is present (step 513), and distance measurement data is selected based on the calculation result. Perform (step 514).

In this way, it is possible to properly select wide-field distance measurement information without using inaccurate short-distance data.

FIG. 28 is a flow chart showing another operation example of the distance measuring device of FIG.

First, when a release switch (not shown) is turned on (step 601), the microprocessor 74 issues a command to perform a distance measuring operation. As a result, the right side area distance measuring means 73 first starts the distance measuring operation (step 6).
02), the left area distance measuring means 71 then starts the distance measuring operation (step 603), and finally the central area distance measuring means 72.
Starts the distance measuring operation (step 604) and obtains distance measuring data in each area.

The distance measurement data in the right area is shown in FIG.
Alternatively, it is judged whether or not it is within the range as described with reference to FIG. 24 (step 605), and if it is out of the range, the range data in the right area is replaced with infinite data ( Step 606) If the distance is within the range, the operation is continued without doing anything.

Next, it is judged whether or not the distance measuring data in the left area is within the distance measuring range described with reference to FIG. 23 or 24 (step 607), and if it is outside the distance measuring range. Similarly, the distance measuring data in the left area is replaced with infinite data (step 608), and if the distance measuring range is within the distance measuring range, the operation is continued without doing anything.

Then, based on the distance measurement data from these areas, distance measurement data selection calculation is performed to determine in which area the subject is likely to be present (step 609), and measurement is performed based on the calculation result. Distance data is determined (step 21)
0).

Here, the reason why the distance data outside the range is set to infinity is that the probability that the subject is infinite is small, and that there is almost no main subject in the vicinity and it is infinite. Therefore, it is similar to lowering the probability of selecting left and right distance measurement data. The reason is that the distance data out of the range is not selected without making the distance data infinite and branching unnecessarily to complicate the program as shown in FIG.

FIG. 29 is a flow chart showing another operation example of the distance measuring device of FIG.

First, when a release switch (not shown) is turned on (step 701), the microprocessor 74 issues a command to perform a distance measuring operation. As a result, first, the right area distance measuring means 73 starts the distance measuring operation (step 702), then the left area distance measuring means 71 starts the distance measuring operation (step 703), and finally the central area distance measuring means 7
2 starts the distance measuring operation (step 704) and obtains the distance measuring data in each area.

The distance measurement data in the right area is shown in FIG.
Alternatively, it is determined whether or not it is within the range-finding area range described with reference to FIG. 24 (step 705), and if it is outside the range-finding range, the probability that the range-finding data in the right area is the object is predetermined. Is set to a low value (step 706), and if it is within the range, the operation is continued without doing anything.

Next, it is judged whether or not the distance measuring data in the left area is within the distance measuring area range described with reference to FIG. 23 or 24 (step 707). If it is outside the distance measuring range. Similarly, the probability that the distance measurement data in the left area is the object is set to a predetermined low value (step 708), and if it is within the distance measurement range, the operation is continued without doing anything.

Then, based on the distance measurement data from these areas, distance measurement data selection calculation is performed to determine in which area the subject is likely to be present.
6, or if the calculation result has already been obtained in step 708, it is adopted (step 709). Then, the distance measurement data is determined based on the calculation result (step 310).

Here, the reason why the probability that the object is the object for the distance data outside the range is set to a predetermined low value is as follows.
As in the case of FIG. 28, the point is that the number of branches is unnecessarily increased and the program is not complicated, and if the subject is at a close distance to the left and right, the distance data is slightly inaccurate rather than infinite. This is because it is considered that the amount of blur is reduced when the distance data on the closest side is adopted.

According to the fourth embodiment, in the active wide-field distance measuring method, if the distance measuring data in the distance measuring area other than the central portion exceeds the distance measuring range, Since the distance measurement data in the central portion is selected without using the distance measurement data, the high brightness saturation has little effect and the performance is high, and the error of the distance measurement data on the short distance side is high. Therefore, it is possible to provide a distance measuring device having less number of errors and less erroneous selection in wide-field distance measuring.

[0135]

As described above, according to the present invention,
When the object distance is determined to be a short distance by the short distance determination means that determines that the object distance is a short distance from the output from the integration means,
An information selection unit that invalidates the infinite information by the infinite determination unit is provided, and when the short distance determination unit determines that the subject information is a short distance, the light is received because the subject is located at a short distance. Assuming that the output of the means on the far side is small and the infinity determination means has performed the infinity determination, the infinity information by the infinity determination means is invalidated.

Therefore, it is possible to reliably prevent output of infinity distance measurement information even if the subject is at a short distance position.

Further, a discriminating means for discriminating whether or not a test mode for adjusting the distance measuring data obtained in a plurality of distance measuring areas is instructed, and a test mode by the discriminating means. If it is determined that the distance measurement operation is performed, distance measurement operation control means for sequentially performing distance measurement operation for each of the plurality of distance measurement areas and sequentially outputting the obtained distance measurement data is provided. A judging means for judging whether or not a test mode for adjusting the distance measuring data obtained in a plurality of distance measuring areas is instructed, and the judging means is in the test mode. Is determined, a distance measuring operation control means for performing the distance measuring operation in the designated distance measuring area and outputting the obtained distance measuring data is provided. It is determined whether or not a test mode for adjusting the obtained distance measurement data is instructed. If the determination mode is determined to be in the test mode, the distance measurement operation for one distance measurement area is performed a predetermined number of times, and the obtained distance measurement data is sequentially output. A distance measuring operation control means is provided
Adjustment for adjusting distance measurement data obtained in a plurality of distance measurement areas, that is, adjustment so that the same distance measurement data is output for the same subject in all distance measurement areas Unlike the normal mode, in the test mode, the only operation necessary for this adjustment is performed sequentially for each ranging area, or for the designated ranging area, or The distance measurement is performed a predetermined number of times for each distance measurement area or a designated distance measurement area.

Therefore, it is possible to adjust each distance measurement data obtained in a plurality of distance measurement areas in a short time.

Further, an adjusting mark is provided at a predetermined position of the light receiving means so that the reflected light from the light projecting means from the object located at a predetermined distance is imaged, and the adjusting mark is provided at the position of the adjusting mark.
The position of the light receiving means is adjusted so that the light reflected by the light projecting means from the subject located at a predetermined distance is imaged.

Therefore, the matching between the light projecting means and the light receiving means can be accurately adjusted to an ideal position, and the efficiency of the adjusting work can be improved.

Further, the distance measuring range of the light receiving means for receiving the reflected light from the subject located in the peripheral area is narrower than the distance measuring range of the light receiving means for receiving the reflected light from the subject located in the central area. If the output from the light receiving means for the peripheral area in the screen is data outside the range in which the light receiving means can measure the distance, the light receiving means for the central area in the screen Equipped with arithmetic means for weighting the output data to calculate distance measurement information, the distance-measurable distance on the short distance side of the light receiving means for the peripheral area is made shorter than that of the central area, and When the distance measurement data of the area exceeds the distance measurement range, that is, the distance measurement data of the short distance in which only the light receiving means for the central area can properly measure the distance is output from the peripheral area. In this case, only the distance measuring data from the light receiving means for the central area, or And so as to increase the ratio to be used of.

Therefore, it is possible to output distance measurement information which has little influence of high brightness saturation and high performance, and which has little error on the short distance side.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a general distance measuring device.

FIG. 2 is a diagram for explaining a case of performing infinity determination in the distance measuring device of FIG.

FIG. 3 is a block diagram showing a schematic configuration of a distance measuring device according to a first embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the distance measuring device of FIG.

FIG. 5 is a diagram showing a distance measuring area within a viewfinder frame in a distance measuring device that changes the distance measuring area according to a change in focal length.

FIG. 6 is a diagram showing a relationship between a focal length, an irradiation angle, and a distance measuring region used in the distance measuring device as shown in FIG.

FIG. 7 is a block diagram showing a schematic configuration of a distance measuring device according to a second embodiment of the present invention.

8 is a flowchart showing the operation of the distance measuring device in FIG.

FIG. 9 is a flowchart showing an operation when a part of FIG. 8 is changed.
It's a chart.

FIG. 10 is a flowchart showing still another operation when a part of FIG. 8 is changed.

11 is a block diagram showing an example of the test mode input means of FIG. 7. FIG.

12 is a block diagram showing another example of the test mode input means of FIG. 7. FIG.

13 is a block diagram showing another example of the test mode input means of FIG. 7. FIG.

FIG. 14 is a diagram showing a light receiving sensor and an adjustment mark according to a third embodiment of the present invention.

FIG. 15 is a diagram for explaining the position adjustment of the light receiving sensor with respect to the light projecting element as shown in FIG. 14;

FIG. 16 is a diagram showing a state after adjustment of the light receiving sensor and the light projecting element according to the third embodiment of the present invention.

FIG. 17 is a diagram showing another example of the light receiving sensor and the adjustment mark according to the third embodiment of the present invention.

FIG. 18 is a diagram showing another example of the light receiving sensor and the adjustment mark according to the third embodiment of the present invention.

FIG. 19 is a block diagram showing a schematic configuration of a distance measuring device according to a fourth embodiment of the present invention.

20 is a diagram for explaining the principle of distance measurement in the distance measuring means of FIG.

FIG. 21 is a diagram showing a configuration of a light receiving means provided in a distance measuring device according to a fourth embodiment of the present invention.

22 is a diagram showing a state of a subject reflected image at each distance onto each light receiving means in FIG. 21. FIG.

FIG. 23 is a diagram showing characteristics of the left and right distance measuring means in FIG. 21.

FIG. 24 is a diagram showing characteristics of the distance measuring unit at the center of FIG. 21.

FIG. 25 is a diagram showing another configuration example of the light receiving means provided in the distance measuring device in the fourth example of the present invention and the state of the reflected image of the subject at each distance to the light receiving means.

FIG. 26 is a diagram showing characteristics of the left and right distance measuring means in FIG. 25.

FIG. 27 is a flow chart showing the operation of the distance measuring device of FIG.
It's a chart.

FIG. 28 is a flowchart showing another operation example of the distance measuring device of FIG. 25.

FIG. 29 is a flowchart showing another operation example of the distance measuring device of FIG. 25.

[Explanation of sign]

12 IRED 13 PSD 23 Comparison circuit 24 Voltage amplification circuit 25 Capacitor 28 Microcomputer 31 Test mode input means 32 Microprocessor 33 Distance measuring means 51, 52, 53, 54a, 54b Distance measuring sensor 61 Distance measuring sensor array 55, 56, 57, 58 Adjustment mark 71, 72, 73 Distance measuring means 74 Microprocessor 81, 82, 83, 84, 85, 92, 93 Distance measuring means

Claims (10)

[Claims] 1. A light projecting means for projecting light toward a subject, a light receiving means for receiving reflected light of the projected light on the subject, an integrating means for integrating an output from the light receiving means, and the integrating means. A distance measuring device having an infinite discriminating means for discriminating that the subject distance is infinite from the output from, a short distance discriminating means for discriminating that the subject distance is a short distance,
A distance measuring device comprising: an information selecting means for invalidating the infinite information by the infiniteness determining means when the short distance determining means determines that the subject distance is a short distance. 2. The distance measuring device according to claim 1, wherein the short distance determining means is means for determining that the subject distance is a short distance based on the output level from the light receiving means. 3. A distance measuring device having a light receiving means for measuring a distance in a plurality of areas within a screen, and a test mode for adjusting distance measuring data obtained in the plurality of distance measuring areas. −
Determination means for determining whether or not the mode is instructed, and when the determination means determines that the mode is the test mode, the distance measurement operation is sequentially performed for each of the plurality of distance measurement areas. And a distance measuring operation control means for sequentially outputting the obtained distance measuring data. 4. A distance measuring device having a light receiving means for measuring a plurality of areas within a screen, and a test mode for adjusting the distance measuring data obtained in the plurality of distance measuring areas. −
Determination means for determining whether or not an instruction is made, and if the determination means determines that the test mode is set, the distance measurement operation of the instructed distance measurement area is performed and obtained. A distance measuring device comprising distance measuring operation control means for outputting distance measuring data. 5. A tester for adjusting the distance measuring data obtained in the plurality of distance measuring areas in a distance measuring device having a light receiving means for measuring the distance of a plurality of areas in the screen. −
Determination means for determining whether or not a command is made, and if the determination means determines that the test mode is set, a distance measurement operation for a predetermined distance measurement area is performed a predetermined number of times to obtain And a distance measuring operation control means for sequentially outputting the measured distance data. 6. A distance measuring device comprising a light projecting means for projecting light toward a subject and a light receiving means for receiving reflected light of the projected light from the subject, wherein the distance from the subject located at a predetermined distance is increased. A distance measuring device, wherein an adjusting mark is provided at a predetermined position of the light receiving means so that the light reflected by the light projecting means is imaged. 7. A distance measuring device comprising a plurality of light projecting means for projecting light toward a subject and a plurality of light receiving means for receiving reflected light of the projected light on the subject, the distance measuring device being located at a predetermined distance. At a predetermined position of the plurality of light receiving means so that reflected light from the plurality of light projecting means from the subject to be imaged is formed,
A distance measuring device characterized in that each has an adjusting mark. 8. The distance measuring apparatus according to claim 6, further comprising an adjustment mark indicating an adjustment allowable range. 9. A plurality of light projecting means for projecting light toward a subject, and a plurality of light projecting means corresponding to the plurality of light projecting means for receiving reflected light from the subject located in the central and peripheral regions of the screen. A light receiving means for receiving the reflected light from the subject located in the central region, within the distance measuring range of the light receiving means for receiving the reflected light from the subject located in the peripheral region. Distance measuring device characterized in that it is narrower than the range that can be measured. 10. A data output from a light receiving means for a peripheral area in a screen is out of a range in which the distance can be measured by the light receiving means.
10. The measuring device according to claim 9, further comprising a calculating device for calculating the distance measuring information by weighting the output data from the light receiving device for the central area in the screen. Distance device.