JP3519782B2 - Distance measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
And the reflected signal light is detected, and the distance of the subject is detected.
The present invention relates to a distance measuring device for a camera that seeks separation. [0002] 2. Description of the Related Art Conventionally, as a distance measuring device (AF) for a camera,
To project light for distance measurement to multiple points on the screen
Then, for example, as shown in FIG.
Even if there is no person as the subject,
Multiple points that can be focused on a person
A technology for measuring the distance (multi-AF) is known. In general, a distance measuring device designed to measure a distance with high accuracy is designed.
In case of light projection type, the projection light amount was increased.
In addition, a technique for increasing the number of light projections is known. Only
In the multi AF mode, the light emission
Applying the technology to increase the number will increase the time lag
I will. Accordingly, the applicant of the present invention has disclosed Japanese Patent Application Laid-Open No. 2-158705.
In Japanese Patent Publication No.
(Pre-ranging) and narrowed down according to the result.
Providing high-precision distance measurement technology (main distance measurement)
I am planning. [0005] As a side effect of multi-AF, a plurality of
If the subject is cluttered in the shooting screen, the original
As a result, the focus point of the main subject is not selected
The out-of-focus phenomenon may occur. Therefore, for example, Japanese Patent Application Laid-Open No. 1-185620.
JP-A-2-264043 and the like.
Techniques for preventing the blur phenomenon have been proposed. this is,
When taking a picture with a composition like R shown in FIG. 3B
Press the release button on the camera
Due to the effect of Multi AF, instead of the main subject person 15
The vase 17 and other people 16 are in focus
U. In order to prevent this phenomenon, first, FIG.
(B) Hold the camera at the position of FL (broken line) and
With the object 15 in the front center, release the camera
Half-press the button, and then compose the composition as shown in FIG.
When using the technique of shooting back to
Distance measurement at the center of the screen when the release button is half-pressed
The result is prioritized. For example, Japanese Patent Laid-Open No. 1-18
No. 5620 discloses that the release button is half-pressed.
Measure the distance twice in the pressed state, and there is no difference
, It was determined that the focus was locked. Also,
In Japanese Unexamined Patent Application Publication No. Hei 2-264043, the release button is half-pressed.
From the time up to the push, the above
The focus lock state has been detected. [0008] However, the aforementioned distance measurement
In the case of the light projection type, distance measurement was performed on the device.
At the time, there is a problem that accuracy is deteriorated due to a decrease in reflected light.
You. That is, a distant subject exists in the screen
Then, the accuracy of the distance measurement value obtained by pre-ranging occurs.
In some cases, the correct ranging point was not selected. Further, Japanese Patent Laid-Open Publication No.
, JP-A-2-264043 and JP-A-2-24
Utilizing the focus lock described in JP-A-6443
The focus lock is used to prevent out-of-focus
After going, I shake the camera and change the composition,
There is a time difference between when you press and when you press the shutter
I have. In particular, if the subject is stationary, there is no problem.
If the subject is
The subject distance differs from the locked state.
There is. [0010] Therefore, in each of the publications, the movement and composition of the subject are described.
Focusing anywhere due to change in subject distance due to figure change
There is a possibility that you can make a picture you do not know. Therefore, the present invention
Measures the distance to the main subject in the composition
Measures for deterioration and reduces energy consumption and time lag
An object of the present invention is to provide a short distance measuring device. [0011] The present invention achieves the above object.
To be operated prior to the camera's release operation.
First switch means, and operation of the first switch means.
A second switch means for performing the release operation later
After the operation of the first switch means, approximately in the shooting screen
Central distance measuring means for measuring the central part, and the second switch means
After performing, perform preliminary ranging for multiple ranging points.
Preliminary distance measurement means,Determines whether the photographer has changed the composition
Determining means for determining the composition, and
If it is determined to have changed,By preliminary ranging
Of the distance measurement results, the distance measurement resultMost
AlsoSelect a ranging point that shows a short distance, and
A distance measuring means for performing a distance measurement for the distance measuring point,
Is provided. [0012] [0013] [0014] The distance measuring device having the above-described configuration is provided with a release button.
After pressing the button to turn on the first release switch
The distance is measured at the approximate center of the shooting screen,
Button to turn on the second release switch.
WasIf the composition changes later,Multiple shooting screens
Preliminary ranging is performed for the ranging points. This reserve
Of the distance measurement results, the distance measurement result by center distance measurementmostnear
Select the ranging point indicating the distance and select the ranging point
Are actually measured. [0015] [0016] [0017] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Will be described. FIG. 1 shows a first embodiment according to the present invention.
The schematic configuration of the distance measuring device is shown and described. [0018] This distance measuring device has a plurality of settings within a shooting screen.
Can measure any of the distance measurement points
Multi AF unit 1 and projection direction for changing the distance measurement point
The switching unit 2 and the power of the distance measuring light of the multi-AF unit 1 are
A power control unit 7 for controlling, and the multi-AF unit
1 and the AF result at that time is
Judgment part (∞ Judgment) to judge whether it is reliable
6) and a level enabling switching of the reference level for this determination.
A bell switching unit 9 and a system for the level switching and ranging device as a whole.
Performance, which consists of a one-chip microcomputer
And a calculation control unit (CPU) 10. In addition,
Provided in CPU 10 and used for distance measurement sequence by ON / OFF
The CPU 10 controls the focusing unit 3 of the camera and the camera.
To release the camera by pressing the release button halfway
The first release SW (1st SW) 4 to be closed and the release
2nd release that is closed by pressing the release button
SW (2nd SW) 5 and 1st SW4, 2n
d A timing unit 8 for timing the input timing of SW5 is provided.
I have. The function of the timer unit 8 is built into the CPU 10.
Is also good. Referring to the flowchart shown in FIG.
The operation of the distance measuring apparatus having the above-described configuration will be described. First,
CPU 10 detects depression of first release SW 4
(Step S1), the CPU 10 controls the power
Through the unit 7, the light emission amount of the AF unit 1 is lowered to a lower level D._A
(Step S2). This is a powerful light
Pre-ranging for many points (multi AF) consumes
That the energy gets bigger,
The reflected signal light is too strong by projecting light, and the AF circuit
For the purpose of preventing 1 from becoming saturated.
You. Next, the distance determination level L_A Set (S
Step S3). In this embodiment, the judgment level of the judgment unit 6
Is easy to judge, ignoring data at long distances,
Only the data in the high-precision area is used. One
In other words, in the case of a light projection type AF using triangulation, AF
The relationship between the output AD of the unit 1 and the reciprocal 1 / L of the subject distance L is
The result is as shown in FIG. D_C Are logical relationships
However, in practice, D / D_A , D_B Shown as
The width of the variation is generated as follows. Light intensity D_A Has low light
If the amount of light emitted is large, D_B More rose than
Width becomes large. As described above, the light amount is reduced by the pre-ranging.
Then, as shown in FIG. 7 (a) as an error of Δ1 / L
And the distance L₁ And L_Two Can not be determined
Cause problems. Therefore, a point P on the screen₁ Measurement
Distance result is L₁ , Other points P_Two Is L_Two Shows the distance measurement result of
At the time of close selection, actually point P₁ Distance L₁
Is closer and point P₁ Main distance measurement for
This variation causes Poi
P_Two There is a problem that the distance is measured again. Therefore, in this embodiment, the variation is large.
Distance L_Three Distance measurement results beyond that are considered to have large errors.
Then, cut as shown in FIG.
So that they can Data cutting by such a long-distance determination
All technologies have been known in the past, and
As for the light, as shown in FIG._Four Data beyond
Try to cut this off as unreliable
You. That is, the distance L_Four The processing that infinity is infinity
So, such a process is called “infinity (∞) judgment”.
Calling. One of the features of the distance measuring apparatus of this embodiment is that
レ ベ ル The level of the determination is determined by the distance L in FIG._Three , L_Four As
Switch to a more reliable
That is, the selection of the multi AF was achieved. Next, returning to FIG._A And distance
Separation judgment level L_A And set the screen as shown in Fig. 2 (b).
The distance measuring light is projected on each point 12 of the
The pre-range measurement of the event is performed (step S4). Next, from the result of the pre-ranging,
Point P indicating the result of distance measurement_x Select (Step S
5) Then point P_x Pre-ranging result and predetermined distance L₀
Are compared (step S6), and the point P_x Is the result of
Distance L₀ If closer (YES), measure with sufficient S / N
It is determined that the distance has been achieved, and the distance measurement result L_x The pin
Is determined (step S10) and step S1
Move to 1. However, the distance measurement result L_x Is a predetermined distance L₀ Yo
When the distance is far (NO), the distance measurement result L_x Accuracy of the distance measurement result
It is determined that it is not sufficient, and the process proceeds to the next step S7.
Then, re-ranging (main ranging) is performed. Prior to the re-ranging, the CPU 10
-Increase the amount of emitted light via the control unit 7 to a large value D_B To
It is reset (step S7), and the level switching unit 9
To determine the judgment level L_B Is better than in pre-ranging
The setting is made so as to be difficult to apply (step S8). Soshi
And point P_x Perform the main ranging to
S9), the press of the release button is determined (step S9).
S11) If the push is determined (YES), the
Distance measurement result L_p (Step S12)
An exposure operation of the camera is performed (step S13). As shown in FIG. 4 (b),
In the case of pre-ranging with 5 points,
P_x In the case of main distance measurement for Also,
In the present embodiment, these pre-ranging are performed in the first ranging mode,
The in-range measurement is set to a second ranging mode. Thus, according to the present embodiment, low power consumption and high
Accurate for the main subject while measuring the distance of many points
It is possible to provide a distance measuring device that focuses on the object. Next
FIG. 5 shows a second embodiment according to the present invention as shown in FIG.
The configuration of the multi-AF section of the distance measuring device described above will be shown and described. The multi AF unit 1 is roughly divided into a light emitting unit and
It consists of a light receiving unit. The light emitting section generates light for distance measurement.
Infrared light emitting diodes (IRED) 22a, 22b,
22c and a driver 4 for sequentially driving the respective IREDs.
Projection that projects light for distance measurement to 0 and 3 points
And a lens 21. The light receiving section reflects light from an object (not shown).
A light receiving lens 24 for condensing the reflected light,
Two powers depending on the incident position of the light
Flow i₁ , I_Two Position detecting element (PSD) 25 that outputs a signal
And preamplifiers 31 and 32 for amplifying a predetermined signal current,
Stationary light removing circuit for removing background light components other than the signal light
30 and the output current i₁ , I_Two Current signal proportional to the sum of
A specific current signal generating circuit 33 for generating a signal;
5, two output currents i₁ , I_Two Ratio operation to calculate the ratio of
The circuit 34 and the output current from the ratio calculation circuit 34 are converted into a voltage.
The resistance 35 to be changed, the voltage level and the reference voltage V_ref And ratio
The comparator 6 compares the reference voltage V_ref Generate
Resistor 36, current sources 37 and 38, and decoder 39
Be composed. The distance measuring light projected from such a light projecting unit
Is reflected by a subject (not shown), and the reflected light
Into a light position detecting element (PSD) 25 through a lens 24
Shoot. The subject is close due to the principle of triangulation
The reflected light (signal light) is on the IRED side on the PSD
Incident far from the camera. The PSD 25 performs photoelectric conversion, and enters
Currents i depending on the incident position of the reflected light₁ , I_Two Output
The preamplifiers 31 and 32 output the signal to a predetermined level.
Amplify the current. The PSD 25 has the signal light.
Remove this component because background light is incident on other than
A stationary light removal circuit 30 is provided. The two output currents i of the PSD 25
₁ , I_Two Ratio i₁ / (I₁ + I_Two ) Is the reciprocal of the distance L 1 /
It is also known that it is proportional to L. Performing this ratio operation
The result of the ratio operation is indicated by AD in FIG.
Show. The output current i₁ , I_Two Proportional to the sum of
A circuit 33 for generating a current signal.
It is the resistor 35 that changes the pressure. This voltage level and the base
Standard voltage V_ref Comparator 6 compares with
You. On the other hand, the reference voltage V_ref Flows a predetermined current through the resistor 36.
It is made by doing. The predetermined current value is supplied to the current sources 37 and 38.
Switching is possible by switching. CPU 10
Via the coder 39, these two current sources 3 depending on the conditions
7 and 38 are switched and the output of comparator 6 is detected.
By doing so, the amount of incident signal at each distance measurement is sufficient S /
It is possible to determine whether or not it has an N ratio. The resistor 36, the current sources 37 and 38,
The level switch 9 is a circuit composed of a power switch and the like. In addition,
The parator 6 corresponds to the ∞ determination unit in FIG. IRED
The flash is fired many times, and the distance measurement results for each flash are averaged.
The technology for improving the ranging accuracy by means of
You. In the present embodiment, the CPU 10
The IREDs 22a, 22b, 22c emit light many times and
Multi-AF of the type that improves the degree
Is different from the amount of light, not the number of flashes in pre-ranging and main ranging
To reduce the time lag. That is, as shown in FIG.
LessThrowIREDs 22a, 22b, 22
c to emit light sequentially, perform multi AF, and
Depends on the result of pre-ranging,
Performs light emission with a large number of light emission times, and performs more accurate ranging.
U. Referring to the flowchart of FIG.
The operation of the second embodiment configured as described above will be described. Ma
The CPU 10 presses a first release SW4 (not shown).
When the current is detected (step S20), the current source 37 is activated.
(ON), and cut off (OFF) the current source 38 (step
Step S21). Next, IREDs 22a, 22b, 22c
Light is emitted three times and the distance L_a (Step S2)
2). Similarly, IREDs 22a, 22b, and 22c are used three times.
The distance L_b Is measured (step S23), and I
The REDs 22a, 22b, and 22c emit light three times, and the distance
L_c Is measured (step S24). As described above, the IREDs 22a, 22b, 22
c is emitted three times, but the number of distance measurements is small, so accuracy
Is not enough. Therefore, the current source 37 is turned on, and
Make the comparator 6 easy to reverse by flowing the judgment current
The distance L as shown in FIG._Three Ignore distance measurement results beyond
To do it. That is, the CPU 10 sets the comparator 6
When the distance is reversed, processing to regard the distance measurement result as ∞ is performed.
I do. Next, the obtained distance L_a , L_b , L_c Within
The point that outputs the closest distance is P_x (Step
Step S25). After that, the current source 37 is cut off (OFF),
The current source 38 is turned on (ON) (step S26). This
This is because the current source 38 is turned on and the current
A current smaller than that of the source 37 is caused to flow through the resistor 36.
Make the judgment difficult. Then, the selected point P_xAgainst
And the main ranging 8 timesRangingResult distance L_p
Get. Then, determine whether the release button has been pressed (
Step S28) The 2nd SW becomes O due to the pushing.
If N (YES), the main distance measurement result L_pFocus on
(Step S29), and perform the exposure operation of the camera.
  (Step S30). In the main distance measurement, the number of flashes is increased.
To improve accuracy. As described above, in this embodiment, the short timer
While measuring many points at high speed with imlag,
Provides a rangefinder that can accurately select the object and measure the distance with high accuracy
it can. FIG. 6 shows a third embodiment according to the present invention.
The configuration of the distance measuring apparatus will be shown and described. This example is
Unlike FIG. 5, it is used as a light emitting element for a strobe or the like.
Xenon discharge arc tube (Xe tube)
Scan the mask 23 with an opening to switch the projection direction.
I'm changing it. This distance measuring device uses a Xe tube 2 as a light projecting element.
2 and a light emitting circuit (power) for causing the Xe tube 22 to emit light.
Control part) 7 and movable to the front of Xe tube 22
The provided mask 23 and a mask for moving the mask 23
Switching unit (light emitting direction switching unit) 2, light emitting lens 21,
The light receiving lens 24 receives the light reflected by the subject.
PSD25, preamplifier, ratio calculation circuit, ∞ judgment circuit and
Focus with AFIC 26 including level switching circuit
Setting part 3, 1st SW4, 2nd SW5, and
And a CPU 10 for controlling them. The distance measuring apparatus having the above-described structure is a mask.
Position control such as scanning is performed by the CPU 10 using the motor feed screw.
And so on through the mask switching unit 2 composed of in this way
When an Xe tube is used as the light emitting element, as shown in FIG.
The light amount is controlled as described in FIG.
It is difficult to perform ON / OFF control. Therefore, as shown in FIG.
Shortens the light emission time and makes the light emission longer during the main distance measurement.
And switch between energy saving and precision priority. One
That is, the light emitting unit 7 switches the time during which the Xe tube current flows.
Function. The CPU 10 is configured as shown in FIG.
At the time of pre-ranging, the mask position
The mask position is determined according to the result, and the main flash
To do. Signal light reflected from the subject
Is input to the PSD 25 via the light receiving lens 24.
The AFIC 26 corresponds to the block 26 in FIG.
Amplifier, ratio calculation circuit, ∞ judgment circuit, level switching circuit, etc.
Integrated circuit. Also in this embodiment, at the time of pre-ranging,
∞The judgment is easy to apply.
It is equivalent to the above-described embodiment to make it difficult to apply,
The description here is omitted. In the third embodiment, far more than IRED
Distance measurement using an Xe tube that can project a large amount of light
Therefore, highly accurate ranging can be performed to a farther distance. Ma
In addition, during pre-ranging, a short light emission time was used,
Design is possible, and the main subject can be selected at high speed
Can be provided. Next, a fourth embodiment according to the present invention will be described.
I will tell. The distance measuring apparatus of the fourth embodiment has the structure shown in FIG.
This is an embodiment in which the operation is the same as that of the embodiment. This
The distance measuring device (multi-AF) of FIG.
Even in the shooting screen, the main subject 15
This is an example of focusing. As described above, a plurality of points on the screen
A camera with an AF that measures the distance and a design that gives priority to the shortest distance
Then, even in a scene as shown in FIG.
Although the focus is adjusted to 15, the system shown in FIG.
Focus on person 16 who is not the main subject
There was a side effect. Therefore, first, the screen is displayed on the FL of FIG.
The camera's release button halfway
Press, then set the screen to the state of R and release button
The focus lock is a shooting technique
Nick gives distance measurement with priority to the center to person 15
It is conceivable to use a focusing method. However, this method originally uses the center of the screen.
Only used in cameras that measure distance
If it is applied to AF as it is, it will be
As for the degree, the person is shifted from the center like the screen of 3 (a)
In this case, the person 15 cannot be focused. The composition change from FL to R in FIG.
The distance between the camera and the subject changes
So, it was necessary to take measures. Flowchart shown in FIG.
The operation of the fourth embodiment will be described with reference to FIG. This
The embodiment of the present invention solves the above-mentioned problem and provides a focus lock.
3B, the composition shown in FIG. 3B is correct.
And was designed to focus on person 15.
You. First, 1 second by half-pressing the release button
The ON of tSW4 is detected (step S40). 1st
  When SW4 is ON (YES), screen center L_c Distance measurement
Perform (step S41). By this distance measurement, FIG.
In a composition like FL shown in FIG.
The separation can be measured. Next, time measurement is performed using the time measurement unit 8 shown in FIG.
Initialize (t = 0) (step S42), 2nd SW
5 is turned on (steps S49, S5).
0). If this time t is long, the user presses the release button halfway.
It can be considered that the composition has been changed while the
You. Therefore, in this embodiment, based on the length of the time t,
Determine whether the photographer has locked the focus
judge. Next, when the second SW5 is turned on (Y
ES), pre-ranging is performed (step S44), and
Time t to a predetermined time t₀ Depends on length compared to
It is determined whether or not the focus is locked (step S4).
5). In this way, the 2nd SW which is turned on at the start of shooting
In this embodiment, multi-AF is performed after that.
Then, a further energy-saving design becomes possible. Next, in step S45, fore
If focus lock determination is made (YES), multi AF
Of the results, the center distance measurement result L measured in step S41
_c The main distance measurement is performed for the point indicating the distance close to
(Step S48), the result is_p And In step S45, the format is
If the scab lock determination is not made (NO), the pre-
Select the point showing the closest value from the results,
The main distance measurement is performed for the directions (step S46). this
The result is L_p And The distance L thus obtained_p Against focus
The alignment is performed (step S47), and the exposure is performed (step S47).
Step S51). In this embodiment, too,
In pre-ranging that requires light, reduce the amount of light to save energy
And Therefore, the appearance of light emission can be represented in a time chart
This is as shown in FIG. As described above, according to this embodiment,
With the release button pressed halfway, measure the distance in the center and check the result.
Remember,ReliMulti AF when pressing the button
Was able to be compared with the result. Also, the release button is half-pressed to
Focus by being able to measure time intervals
Can determine the will of the lock. So this time interval is long
If so, it is likely that the user has changed the composition,
The center distance measurement result when the 1st SW4 is ON and the multi
Compare the AF results and select the
The point indicating the distance close to the center ranging result is the main subject
As a position. For example, in a composition as shown in FIG.
Pressing the release button halfway at the FL position
15 distance L_c Can be stored in advance. Next, the composition
Change to R and press the release button.
Because the multi-point is multi AF, these three points
Chi, most L_c The distance measurement point on the left indicates the distance
So, re-ranging (main ranging) for this point
U. After the composition has been changed in this way, a large amount of light is again applied.
It measures the distance and focuses according to this result.
Accurate pins that are not affected by distance changes due to diagram changes
Can be matched. When there is no focus lock judgment
In (N branch of S45), normal multi AF is performed. As described above, according to the present embodiment,
Energy-saving design and high accuracy while solving the side effects of Luci AF
Can be provided. But this second
In the fourth embodiment, the composition shown in FIG.
When the ズ button is pressed halfway, the center is given priority and the landscape
There was a problem that the camera was in focus. Therefore, a distance measuring apparatus according to a fifth embodiment will be described.
Will be described. FIG. 11A shows the configuration of the fifth embodiment.
FIG. 11B shows a flowchart for explaining the operation.
A flowchart is shown and described. In this distance measuring apparatus, a plurality of
Can measure any of the distance measurement points
Multi AF unit 1 and projection direction for changing the distance measurement point
Number of projections of distance measuring light by switching section 2 and multi-AF section 1
And the multi-AF unit 1
AF result at that time is more reliable than the amount of reflected signal received
A judgment unit 6 for judging whether or not the judgment is possible.
A level switching unit 9 for switching a reference level for determination
And the sequence of the entire level switching and ranging device.
And an arithmetic control unit (CPU) 10 for controlling the operation. Further
Is provided in the CPU 10 and measured by ON / OFF.
The distance sequence and the focusing unit 3 of the camera are
Half-pressed release button of camera to control 0
Release SW (1st SW) closed by state
Closed by pressing the 4 and release buttons
2nd release SW (2nd SW) 5 and 1st SW
Timer to measure input timing of 4,2nd SW5
8, the zoom lens 50, and the focal length of the zoom lens 50
An f input unit 51 including an encoder for inputting the separation f is provided.
I have. The function of the timer 8 is built in the CPU 10.
Is also good. This distance measuring device is used for the focal length of a camera photographing lens.
The separation (f) is taken into consideration, as shown in FIG.
If the camera lens is a zoom lens,
Input unit consisting of an encoder or the like to set the focal length f of the lens 50
The configuration is such that the CPU 10 can read through the CPU 51.
I have. Other components are substantially the same as those shown in FIG.Bodongetc
However, instead of the floodlight power control 7,
The number of times of light emission switching as shown in FIG.
Control is possible. Next, refer to the flowchart of FIG.
I will explain. The flowchart of FIG.
It is almost the same as the flowchart of FIG.
Only the part will be described. First, the center distance measurement and the step
In the pre-ranging of step S65, the number of projections is reduced (for example, 3
Times) and the re-ranging in steps S67 and S71
Sets the number of light projections to be relatively large (for example, eight times). On the other hand, the level switching means 9 for judging
When the number of times is small, it is easy to set and the number of times of light emission is large
At times, it is configured to be set relatively hardly. Ma
The flowchart of FIG. 11B is applied to step S61.
Input the focal length of the photographing lens via the f input unit 51,
In consideration of the result, in step S70, the focus
The judgment of the lock is performed. That is, in step S70
Center distance measurement result L_c Is greater than or equal to 80 × f, step S
The process branches to 67 and focus lock is not performed. example
For a lens with f = 50 mm, L_c Is 50mm × 80
= 4 m or more, it is determined that the focus is not locked
You. Therefore, in the scene as shown in FIG.
Because the scenery is a landscape, L_c Is 4m or more, so focus
Not considered as a throck, the closest selection in step S67
Select the correct distance to focus on the person 15
It becomes possible. It should be noted that the numerical value of 80 times here is almost
It is determined from the distance at which a photograph equivalent to a full-body image can be taken.
You. As described above, in this example, the side effect was solved.
A multi-AF camera can be provided. According to the above embodiment of the present invention,
The following configuration is obtained. (1) Projector that projects light for distance measurement toward the object to be measured
Step, receiving reflected light from the object to be measured, and
Light receiving that outputs a photoelectric conversion signal according to the distance to the object
Means based on the photoelectric conversion signal from the light receiving means.
Determination means for performing infinity determination by means of
Light intensity cutoff to switch the light emission amount or the number of times of the above distance measurement light
Switching means and the light amount switching means.
When the number of times of light emission is changed,
Decision level switching means for switching the decision level of
Distance measuring device characterized by doing. Therefore, according to the distance measuring apparatus described in the above (1),
For example, the infinity judgment level can be set according to the
Since the switching is performed, a more reliable distance measuring device can be obtained. (2) The determination level switching means is the light quantity switching means.
If the light emission amount is reduced by
The measurement according to the above (1) is switched to a level determined to be infinity.
Distance device. Therefore, in the distance measuring apparatus according to the above (1),
The reflected light from a distant place decreases when the projected light amount is small
Although the reliability is low, the distance measuring device described in (2) above is
According to this, a more reliable distance measuring device is obtained. (3) The light emission amount switching means sets the light emission time
Change the projection light amount of the distance measuring light by changing
The distance measuring device according to the above (1) or (2). Therefore,
According to the distance measuring device described in (3), for example, a flash light emitting device
Repeated on / off when used as light emitting means
It is convenient when it is troublesome. (4) The projection light amount switching means hits once.
To change the number of projections while keeping the
The distance measuring device according to (1) or (2). Therefore,
According to the distance measuring device described in (4), the light emitting time per one time
This is convenient when using light projection
Is good. (5) The light emitting means can measure a plurality of distances.
The light amount switching means continuously measures the distance at a plurality of points.
(1) to (4), which reduce the amount of projected light
On-board equipment. Therefore, according to the distance measuring apparatus described in the above (5),
For example, when measuring the distance at multiple points,
Thus, waste of light emission energy can be prevented. (6) Emit ranging light to multiple ranging points
And the reflected light from the distance measuring point
And outputs a photoelectric conversion signal according to the distance to the object to be measured
Receiving means for measuring the distance based on the photoelectric conversion signal
Distance calculating means for calculating the distance to the object;
Light to a plurality of ranging points by
A first ranging mode in which the distance is calculated by the distance calculating means;
About a predetermined distance measuring point by the light emitting means
The second measurement is performed by projecting light and calculating the distance by the distance calculating means.
A distance measuring mode control means for switching between a distance mode and the second
When the ranging mode is selected, the first ranging mode
Compared to the case where is selected,
Light quantity control means for increasing the light quantity of the distance light.
Distance measuring device characterized by doing. Therefore, according to the distance measuring apparatus described in the above (6),
Reduces energy consumption even when measuring distances at multiple points
be able to. (7) In the first ranging mode, the light is emitted by the light emitting means.
(6) wherein the light is sequentially projected in different directions.
Distance measuring device. Therefore, according to the distance measuring apparatus described in the above (7),
For example, since multiple points are measured sequentially, multiple points are measured at the same time.
Compared to the case, the distance measurement light does not interfere. (8) It is determined whether the object is at infinity based on the photoelectric conversion signal.
The first ranging mode and the second ranging mode.
The above (6), in which the judgment level differs between modes
Or the distance measuring apparatus according to (7). Therefore, according to the distance measuring apparatus described in the above (8),
High reliability because the judgment level at infinity is changed.
Distance measurement. (9) The distance measurement mode switching means includes a first distance measurement mode.
After the end of the distance measurement, based on the distance measurement result in the first
(6) performing distance measurement in the second distance measurement mode
The distance measuring device according to (8). Therefore, according to the distance measuring apparatus described in the above (9),
For example, since the actual ranging can be performed based on the ranging results of multiple points,
More accurate ranging can be performed in a short time. (10) The light projecting amount control means is a light projecting means of the light projecting means.
(6) to (9) for controlling the time or the number of light projections
The distance measuring device as described. Therefore, according to the distance measuring apparatus described in the above (10),
This makes it possible to easily control the amount of projected light. (11) Operated prior to camera release operation
First switch means and after operation of the first switch means
A second switch means for performing the release operation.
After the operation of the first switch means, approximately in the shooting screen
Central distance measuring means for measuring the central part, and the second switch means
After performing, perform preliminary ranging for multiple ranging points.
Preliminary distance measuring means and the result of distance measurement by the preliminary distance measuring means.
Of which, a distance measuring point close to the result of distance measurement by the central distance measuring means
Select the focus measurement point and
Measuring means for performing distance measurement.
Distance device. Therefore, according to the distance measuring apparatus described in the above (11),
Then, the center of the screen when the first switch is operated
Since the actual distance measurement will be performed later for the object
Distance can be measured. (12) Operation of the first switch means
From the time when the above operation is performed by the second switch means
Timekeeping means for measuring the time between
If the time is equal to or greater than the predetermined value,
The distance measurement point close to the distance measurement result by the central distance measurement means
The distance measuring apparatus according to the above (11), wherein the distance is measured. Therefore, according to the distance measuring apparatus described in the above (12),
Focus lock can be performed easily and accurately.
Distance can be done. (13) The main distance measuring means measures the time by the time measuring means.
If the time is less than the specified value,
Select a ranging point regardless of the ranging result and perform actual ranging
The distance measuring apparatus according to the above (12). Therefore, according to the distance measuring apparatus described in the above (13),
If the measured time is within the specified value, the focus
Not fixed to the rack. (14) The result of distance measurement by the central distance measuring means is equal to or less than a predetermined value.
If it is far away, change the distance measurement point
The distance measuring apparatus according to the above (11), further. Therefore, according to the distance measuring apparatus described in the above (14),
If the distance is longer than the predetermined value, the
Since the points are changed, it is possible to prevent hollowing out
You. (15) The above predetermined value depends on the photographing magnification.
The distance measuring apparatus according to the above (14), wherein Therefore,
According to the distance measuring apparatus described in (15), the middle distance is determined according to the focal length.
Dropout can be prevented. (16) To a plurality of points on the picture screen
On the other hand, a light projecting means for sequentially projecting the distance measuring light,
Means for changing the projection direction, and the light amount of the distance measuring light.
Light amount switching means for switching, and the distance measuring light from the subject
Receives reflected signal light and outputs distance measurement results for each point
Do not project the light receiving means and the distance measuring light sequentially in different directions.
A first ranging mode for measuring the distance of each point,
One point distance measurement by projecting the above distance measurement light in a predetermined direction
Control means for switching a second ranging mode for performing
A distance measuring device characterized in that: (17) The control means performs the first distance measurement.
Change the light amount switching means in the mode and the second ranging mode
The distance measuring apparatus according to the above (16), wherein: Measurement
Distance device. (18) The light receiving means is the reflected signal light.
Determination means for comparing the level of the image with a predetermined determination level
The control means controls the first distance measurement mode and the second distance measurement.
Characterized in that the judgment level is switched in a mode.
The distance measuring apparatus according to (16). (19) The light amount switching means determines the number of times light is projected.
The distance measuring apparatus according to the above (16), wherein the distance measuring apparatus is changed. (20) Before pressing the release button of the camera
Press the first switch to close and the release button
The second switch, which is closed when the
Equipped with timing means for timing the difference
The control means displays the screen when the first switch is closed.
For the central part, the above-mentioned changing means is controlled so as to emit light,
When the second switch is closed, the first distance measurement mode is set.
And the timed result of the timed means is equal to or longer than a predetermined time.
In the case of, the distance measurement result obtained in the first distance measurement mode is
Of which, the distance measurement result closest to the distance measurement result
I will re-project the ranging light to the ranging point
(1) controlling the light projecting means as described above.
7) The distance measuring device according to the above. (21) If the distance measurement result at the center of the screen is
If this is the case, the point of the re-ranging is changed.
(20). [0096] According to the present invention as described in detail above,
Low energy consumption while taking measures against accuracy deterioration due to distance measurement
Or a distance measuring device that can perform multi-AF with a short time lag
Can be provided. Also, it is easy to occur in multi AF.
To resolve the blur caused by the composition
Distance measurement that prevents blurring due to so-called hollow holes
An apparatus can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows and describes a schematic configuration of a distance measuring apparatus as a first embodiment according to the present invention. FIG. 2 is a diagram showing the positions of distance measurement points in a screen to be photographed. FIG. 3A is a diagram illustrating an example of an arrangement of a subject on a screen to be photographed, and FIG. 3B is a diagram illustrating an example of an arrangement of a subject on a screen to be photographed with focus lock. FIG. 4 is a flowchart for explaining the operation of the distance measuring apparatus of the first embodiment. FIG. 5 is a diagram showing a configuration of a multi-AF section of the distance measuring apparatus shown in FIG. 1 as a second embodiment according to the present invention. FIG. 6 is a diagram showing a configuration of a distance measuring apparatus as a third embodiment according to the present invention. FIG. 7 shows the reciprocal 1 / L of the output AD of the AF unit and the subject distance L.
FIG. FIG. 8 is a timing chart showing light emission timing of distance measuring light. FIG. 9 is a flowchart illustrating the operation of the distance measuring apparatus according to the second embodiment. FIG. 10 is a flowchart for explaining the operation of the distance measuring apparatus of the fourth embodiment. FIG. 11A is a diagram showing a configuration of a fifth embodiment, and FIG. 11B is a diagram showing a flowchart for explaining the operation thereof. [Description of Signs] 1 ... Multi AF unit, 2 ... Projection direction switching unit, 3 ... Focusing unit, 4 ... First release SW (1st SW), 5 ... Second release SW (2nd SW), 6 ... Judgment Unit (∞ determination unit), 7: power control unit, 8: timer, 9: level switching unit, 10: arithmetic control unit (CPU).

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Claims (1)

(57) [Claims 1] First switch means operated prior to the release operation of the camera, and second switch for performing the release operation after the operation of the first switch means. Means, a central distance measuring means for measuring a distance substantially at the center of the photographing screen after the first switch means is operated, and a preliminary distance measuring for a plurality of distance measuring points after operating the second switch means. Distance means, determining means for determining whether the photographer has changed the composition, and determining that the photographer has changed the composition by the determining means.
In this case, the distance measuring point indicating the distance closest to the distance measuring result by the central distance measuring means is selected from the distance measuring results by the preliminary distance measuring means, and the distance measuring point is selected for the selected distance measuring point. And a distance measuring device for performing the following.