JP2002131620A - Range-finding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a passive type range-finding device having a charge storage type sensor, made inexpensive and providing an appropriate integration signal in every photographic scene. SOLUTION: In this range-finding device, object light is received by a light receiving means equipped with a plurality of photodetectors, and a defocus amount or a distance to an object is measured, based on integration output from the light receiving means. The device is provided with a 1st integration control means comparing monitor output indicating integration circumstances produced from the light receiving means with a specified value and finishing the integration operation by the light receiving means when deciding that the monitor output exceeds a given value, a 2nd integration control means referring to the monitor output indicating the integration circumstance produced from the light receiving means, determining whether or not the integration operation by the light receiving means is performed at an appropriate integration level and finishing the integration operation by the light receiving means when judging that the integration operation by the light receiving means is performed at the appropriate integration level, and a control means switching the 1st and the 2nd integration control means and making them effective.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring apparatus, and more particularly to a distance measuring apparatus that can be used for a single-lens reflex camera, a compact camera, and the like.

[0002]

2. Description of the Related Art A distance measuring device using a charge storage type sensor is:
It is widely used in optical devices such as film cameras and digital cameras.

[0003] Also, a number of techniques relating to an accumulation (integration) control method of a charge accumulation type sensor have been disclosed.

For example, Japanese Patent Application Laid-Open No. Hei 8-152551 has a circuit for selecting a monitor output indicating the maximum value among monitor outputs indicating the accumulation status of a plurality of charge accumulation sensors, and only the maximum value is set to one line. There is disclosed a technique in which an output signal line is output to compare with a predetermined value, and control is performed so as to stop the integration when the predetermined value is reached.

Japanese Patent Laid-Open Publication No. Hei 10-288732 discloses that the monitor outputs of a plurality of charge storage sensors are switched and sequentially referred to, and a proper storage time is predicted and calculated from the monitor output values at that time. A technique for controlling the accumulation time is disclosed.

[0006]

However, according to the technique disclosed in Japanese Patent Application Laid-Open No. 8-152551, only the sensor having the maximum monitor output among a plurality of charge storage sensors is output. I do not know the status of the monitor output of the charge storage sensor other than the value.

Accordingly, the distance measurement area (charge storage type sensor)
Since it is not possible to recognize the luminance difference between the two, it is not possible to determine a shooting scene with a backlight or a night scene as a background, and there is a problem that the main subject is out of focus.

In the technique disclosed in Japanese Patent Application Laid-Open No. H10-288732, when an object has high luminance, the integration signal changes rapidly, so that the integration signals of a plurality of charge storage sensors are monitored at high speed. Therefore, there is a problem that a high-speed processing device such as a myco-computer is required and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a charge accumulation type sensor, and is a low cost and passive type distance measuring apparatus capable of obtaining an appropriate integrated signal in all photographing scenes. It is intended to provide a device.

[0010]

According to the present invention, in order to solve the above problems, (1) subject light is received by light receiving means having a plurality of light receiving elements, and based on an integrated output from the light receiving means. In a distance measuring device that measures the defocus amount or the distance to the subject, a monitor output indicating an integration state generated from the light receiving unit is compared with a predetermined value, and when it is determined that the monitor output has exceeded the predetermined value, With reference to first integration control means for terminating the integration operation of the light receiving means and a monitor output indicating the integration status generated from the light receiving means, the integration operation by the light receiving means is performed at an appropriate integration level. A second integration control means for terminating the integration operation of the light receiving means when it is determined whether or not the integration operation by the light receiving means is performed at a proper integration level; A first integration control means;
Control means for switching and validating the integral control means of
A distance measuring device characterized by having:

According to the present invention, in order to solve the above-mentioned problems, (2) the light receiving means comprises a plurality of light receiving means each provided with a plurality of light receiving elements. The distance measuring apparatus according to (1), wherein the first integration control means and the second integration control means can be selected for each of the two.

According to the present invention, in order to solve the above-mentioned problems, (3) the first integration control means and the second integration control means are integrated with the light receiving means by an integration time and an operation. The ranging device according to (1) or (2) is provided, wherein the switching is performed according to a mode and a ranging area position.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a main circuit configuration of a passive distance measuring apparatus applied as a first embodiment of the present invention.

As shown in FIG. 1, a distance measuring sensor 11, which is a charge storage type sensor, includes three line sensors 12A, 12B, 12C provided at predetermined intervals,
It has processing circuit sections 13A, 13B, 13C provided adjacent to 2A, 12B, 12C.

Here, each of the line sensors 12A, 12B,
12C is a so-called photodiode array,
Photodiodes (pixels) that respectively receive the subject light flux and perform photoelectric conversion are provided along a straight line at fixed intervals (pitch).

The electric charges generated in each of the line sensors 12A, 12B, 12C are accumulated in the accumulating units in the processing circuit units 13A, 13B, 13C corresponding to each sensor and converted into voltage signals.

Each of the processing circuit units 13A, 13B, 1
The pixel signals converted into the voltage signals in 3C are sequentially read, and an image signal is output as an integrated signal in pixel units.

A microcomputer (hereinafter, referred to as a microcomputer) 21 as a controller of the entire distance measuring device operates based on a program stored in a ROM 22 therein to control the operation of the entire distance measuring device.

The microcomputer 21 outputs a control signal to the distance measuring sensor 11 and controls the operation of the distance measuring sensor 11 via a control circuit 14 in the distance measuring sensor 11.

The image signals from the line sensors 12A, 12B, 12C are supplied to the processing circuit units 13A, 13B, 13C.
The A / D conversion circuit 25 output from the microcomputer 21 through the output circuits 15A, 15B, and 15C.
Is input to

Each of the line sensors 12A, 12B,
The image signal from 12C is converted into pixel data of a digital signal by the A / D conversion circuit 25, and is sequentially stored at a predetermined address in the RAM 23 inside the microcomputer 21.

The microcomputer 21 reads out pixel data of a necessary area from the RAM 23 and uses it for distance measurement.

Next, two types of integration control methods of the distance measuring sensor 11 will be described.

Each line sensor 12A, 12B, 12C
Starts an integration operation when an integration start signal is input from the integration control circuit 18 via the control circuit 14 according to an instruction from the microcomputer 21.

Monitor circuits 16A, 16B, and 16C for outputting the charge storage amounts of the line sensors 12A, 12B, and 12C are provided to the processing circuit sections 13A, 13B, and 13C.
, Respectively.

Each of the monitor circuits 16A, 16B, 16C
Each of the line sensors 12A, 12B, and 12C generates a peak signal among the subject image signals received by the line sensors 12A, 12B, and 12C, and outputs the peak signal to the integration control circuit 18.

The judgment voltage Vth generated by the judgment voltage generation circuit 44 is input to the integration control circuit 18.

Here, as shown in FIG. 9, the integration control circuit 18 supplies the judgment voltage Vth and the monitor circuits 16A and 16A.
Monitor outputs A, B, C which are output voltages from B, 16C
Are built in.

When the integration control circuit 18 detects that the monitor outputs A, B, C exceed the judgment voltage Vth, it outputs the integration end signals ENDa-ENDc to the processing circuit sections 13A, 13B, 13C. Line sensor 12A,
The charge accumulation (integration) of 12B and 12C is terminated.

At the same time, each line sensor 12 is controlled by a timer counter 26 in the integration control circuit 18.
The integration times of A, 12B and 12C are measured.

The timer counter 26 is provided with the oscillation circuit 2
The clock generated by 8 is counted.

Each line sensor 12A, 1 for which integration has been completed
The integration time data of 2B and 12C is recorded in the memory 27 in the integration control circuit 18.

The microcomputer 21 reads out the integration time data recorded in the memory 27 by communication between the microcomputer 21 and the control circuit 14 and stores the data in the RAM 23.

Here, the integration time data is used as data for judging whether or not to project the AF auxiliary light and for performing spot photometry on the corresponding distance measurement area.

The integration termination process by the integration control circuit 18 is called a hard integration control mode.

On the other hand, each monitor circuit 16A, 16B, 16
The monitor output of C is output from the monitor output circuits 17A and 17A, respectively.
7B and 17C, the A /
It is input to the D conversion circuit 25.

The microcomputer 21 includes the line sensors 12A,
The A / D conversion circuit 25 performs A / D conversion of the monitor signal for each of the 12B and 12C. When the monitor output reaches a predetermined value with reference to the A / D conversion value, the integration end signal ENDM
Is input to the distance measurement sensor 11 to terminate the integration operation of the corresponding line sensor.

The image signal output circuits 15A, 15B, 1
5C and the outputs of the monitor output circuits 17A, 17B and 17A are input to the switch circuit 19, and are selected by a control signal from the microcomputer 21 to the control circuit 14 to generate an image signal /
The signal is output from the monitor output signal terminal and input to the A / D conversion circuit 25 built in the microcomputer 21.

The integration end signal E from the microcomputer 21
NDM and integration end signal END of integration control circuit 18
1, END2 and END3 are input to the switch circuit 20, selected according to a control signal from the microcomputer 21 to the control circuit 14, and input to the processing circuits 13A, 13B, 13C and the control circuit 14.

As described above, the number of terminals of the distance measuring sensor 11 is reduced to reduce cost, mounting area, and the like.

The above-described integration end processing by the microcomputer 21 is called a soft integration control mode.

As described above, the distance measuring apparatus according to the present invention has two types of integration control modes, which can be properly used depending on the situation.

FIGS. 2A and 2B are diagrams showing the configuration of a camera and a distance measuring optical system when the distance measuring sensor 11 is applied to a TTL passive system of a single-lens reflex camera.

As shown in FIGS. 2A and 2B, the light beam from the subject passes through the taking lens 71 and enters the main mirror 72.

The main mirror 72 is a half mirror, and a part of the incident light beam is reflected toward the finder optical system 74.

On the other hand, the remainder of the incident light beam is
After being transmitted through 2 and reflected by the sub-mirror 73, it is guided to the distance measuring unit 78.

The finder optical system 74 includes a screen 7
5. The photographed image is allowed to be observed by the photographer through the center prism 76 and the eyepiece 77.

At the time of film exposure, the main mirror 72 and the sub mirror 73 are retracted to the positions indicated by the dotted lines in the figure.

The luminous flux of the subject having passed through the photographing lens 71 is exposed to the film 79 or the image pickup device through the opening of a shutter (not shown).

Next, the distance measuring optical system in the distance measuring unit 78 in the single-lens reflex camera will be described.

A field mask 51 is arranged on a focal plane where a light beam from a subject passes through predetermined areas 71a and 71b of the photographing lens 71 and a subject image is formed.

The field mask 51 has openings 51A, 51B, 51C for regulating the distance measurement area, and vertically elongated rectangular openings 51A, 51B, 51C are formed at regular intervals along the horizontal direction. Individually formed.

The predetermined focal plane is a plane equivalent to a film plane in the case of a so-called silver halide film camera, and a plane equivalent to a light receiving plane of an image sensor in an electronic still camera.

Each of the openings 51A, 51B,
A condenser lens 52 is arranged behind 51C.

The luminous flux transmitted through each of the openings 51A, 51B, 51C is condensed by a condenser lens 52 and then split into two by a pair of separator lenses 53, 54.

Each of the two divided images is applied to each of the line sensors 12A, 12B, 1 arranged on the secondary image plane.
2C projected onto different areas.

Here, the secondary image forming surface is a surface on which an image of a predetermined image forming surface is formed, and an image of a subject by the photographing lens 71 is formed on this secondary image forming surface.

The mirror in the distance measuring unit 78 includes a condenser lens 52, a pair of separator lenses 53,
54, but is omitted in FIG.

FIG. 3 shows distance measuring areas 112A, 112B, 11 in the photographing screen 100 of the single-lens reflex camera.
2C is shown.

FIG. 4 shows a microcomputer 2 in the distance measuring apparatus.
3 is a flowchart for explaining a distance measuring operation by No. 1.

FIG. 8 shows the microcomputer 2 in the distance measuring apparatus.
6 is a time chart for explaining a distance measuring operation by No. 1.

First, in step S201, the microcomputer 21 communicates with the control circuit 14 to
Set 1 to the hard integration control mode.

Next, in step S202, the microcomputer 2
1 inputs an integration start signal to the control circuit 14, and each of the line sensors 12A, 12B, and 12C starts an integration operation (see FIG. 8A).

The microcomputer 21 starts an internal counter at the same time as the start of the integration operation, and measures time.

Here, the counter corresponds to each line sensor 12.
In addition to measuring the integration time of A, 12B, and 12C, it is used for switching the integration control mode.

Next, in step S203, the line sensors 12A, 12B, 12
The integration operation of C is controlled to be terminated when the integration control circuit 18 detects that the monitor output exceeds a predetermined determination value (see (c) and (d) of FIG. 8).

Next, in step S204, it is determined whether or not the integration operation has been completed for all the line sensors based on the integration completion signal.
Then, if there is a line sensor for which integration has not been completed, the process returns to step S203.

Next, in step S205, it is checked whether or not a predetermined time has elapsed since the start of the integration. If it is within the predetermined time, the flow returns to step S203 to repeat the hard integration for the line sensor whose integration has not been completed. Control is performed, and if the predetermined time has elapsed, step S20
Proceed to 6.

Next, in step S206, the control circuit 1
4 sets a soft integration control mode by a control signal from the microcomputer 21.

Next, in step S207, the monitor output of the line sensor that is still performing the integration operation is input (see FIG. 8B).

Next, in step S208, when it is determined that the integration end time has been reached by a predetermined determination method, the integration is terminated (see FIG. 8 (e)).

Next, in step S209, it is determined whether or not the integration operation has been completed for all the line sensors. If the integration operation has been completed, the process proceeds to step S210.
If there is a line sensor that has not yet completed the integration operation, the process returns to step S203.

Next, in step S210, it is determined whether or not the output voltage of the monitor circuit has not reached the predetermined voltage within the integration limit time. If the output voltage has not reached the integration limit time, the flow returns to step S207 to perform soft integration. The control operation is performed, and when the integration limit time has been reached, the process proceeds to step S211.

Next, in step S211, when the integration limit time has elapsed, the corresponding line sensor 12A, 1
The integration of 2B and 12C is forcibly terminated.

Next, in step S212, a control signal is input to the control circuit 14 in the distance measuring sensor 11, and the charges stored in the photodiodes of the selected line sensors 12A, 12B, and 12C are used as image signals as A / A signals. D-convert and read.

Next, in step S213, based on the pair of image signals from the line sensors 12A, 12B and 12C stored in the RAM, each of the line sensors 12A, 12
A pair of image intervals is obtained for each of B and 12C, and a defocus amount is calculated.

Next, in step S214, the defocus amount obtained for each of the line sensors 12A, 12B, and 12C is processed using a predetermined algorithm, and, for example, the closest defocus amount is selected.

Next, the processing in the soft integration control mode will be described.

In the hard integration control mode described above, the comparison judgment value of the monitor output is determined by taking into account the change speed of the integration signal at high luminance and the delay such as the operation delay of the integration control circuit. To ensure that the image signal is within the dynamic range, as shown in FIG.
The level is set at almost 50%.

When the change of the integrated signal at the time of middle and low luminance is slow, the same comparison judgment value is used to obtain a sufficient contrast of the image signal for a low-contrast subject. There is a problem that the detection accuracy is reduced (see monitor outputs B and C in FIG. 8B).

On the other hand, in the soft integration control mode, the integration operation can be terminated by inputting and judging a monitor output, so that control with a high degree of freedom without hardware restrictions is possible.

That is, in the soft integration control mode, the judgment value is set to a larger value, and as shown in FIG. 5B, the level is set to approximately 90% to increase the contrast of the image signal. Control is performed (see the monitor output A in FIG. 8B).

As described above, in the soft integration control mode, the distance can be measured even for a subject having a low contrast.

As described above, when high-speed integration control is required for a high-luminance subject, that is, at the beginning of the integration start, control is performed in the hard integration control mode by the integration control circuit 18.

While high-speed operation is not required, integration control of a low-luminance object is performed in a relatively low-speed and low-cost soft integration control mode by the microcomputer 21 to perform highly accurate distance measurement.

Further, since the integration control processing is performed in a distributed manner, each processing unit can be configured at low cost.

Further, only a relatively short integration time is measured by the timer counter 26 in the distance measuring sensor 11, and a longer integration time is measured by the microcomputer 21, so that the circuit scale of the timer counter 26 can be reduced. In addition, the chip size of the distance measuring sensor 11 can be reduced to reduce the cost.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
This embodiment will be described, however, since the configuration is the same as that of the above-described first embodiment, the description thereof will be omitted, and only different portions of the operation will be described below.

In the second embodiment, the luminance difference between line sensors (ranging areas) can be determined from the monitor output of each line sensor by the soft integration control.

That is, when the luminance difference between the line sensors is large, it can be estimated that there is a high possibility that the subject as shown in FIG. 6 is a person having a night view as a background or a backlight scene.

In such a case, it can be estimated that the low-luminance portion is the main subject. Therefore, the control is performed so as to increase the judgment value or the integration time by increasing the integration value. Do.

FIG. 7 is a flowchart for explaining a distance measuring operation according to the second embodiment.

FIG. 13 is a time chart for explaining the distance measuring operation according to the second embodiment.

First, in step S301, the microcomputer 21 communicates with the control circuit 14 to
Set 1 to the hard integration control mode.

Next, in step S302, the microcomputer 2
1 inputs an integration start signal to the control circuit 14, and each of the line sensors 12A, 12B, and 12C starts an integration operation (see FIG. 13A).

The microcomputer 21 starts the internal timer counter 24 at the same time as the start of the integration operation, and measures time.

Here, the timer counter 24 is used for switching the integration control mode in addition to measuring the integration time of the line sensor.

Next, in step S303, the hard integration control mode ends, and the line sensors 12A, 12B,
The integration operation of 12C is controlled so as to be terminated when the integration control circuit 18 detects that the monitor output exceeds a predetermined determination value (see (c) and (d) of FIG. 13).

Next, in step S304, it is determined whether or not the integration operation has been completed for all the line sensors based on the integration completion signal.
The process returns to step S303 if there is a line sensor for which integration has not been completed.

Next, in step S305, it is checked whether or not a predetermined time has elapsed since the start of integration. If it is within the predetermined time, the flow returns to step S203 to repeat the hard integration for the line sensor whose integration has not been completed. The control is performed, and if the predetermined time has elapsed, step S30
Proceed to 6.

Next, in step S306, the control circuit 1
4 sets a soft integration control mode by a control signal from the microcomputer 21.

Next, in step S307, the monitor output of the line sensor that is continuing the integration operation is inputted and checked.

In this case, as for the monitor output of the line sensor which has already been integrated, the monitor value at the time of completion of the integration is held in the monitor circuit, so that the monitor value is read out (monitor shown in FIG. 13B). Outputs A, B, C).

Next, in step S308, a monitor output difference is calculated by comparing monitor values between a plurality of line sensors.

Here, the difference in integration time for each line sensor is corrected, the monitor values corresponding to the same integration time are compared, and the difference between the maximum value (MAX) and the minimum value (MIN) is calculated and determined. Compare with value.

For example, the comparison between the monitor output A and the monitor output B is performed by comparing VMA with VMB · TA / TB.

Here, the monitor output A of the integration time TA is V
MA, and the monitor output B of the integration time TB is VMB (measurement is TA).

Next, in step S309, if the difference between the maximum value (MAX) and the minimum value (MIN) is not less than a predetermined value as the monitor output difference, the subject is a person or a backlight scene with a night view as a background. Is determined.

Then, it is determined that an image of the main subject is formed on the line sensor (line sensor 12A) in the distance measuring area on the low luminance side, and a process for increasing the integral amount described below is performed.

First, in step S310, if the luminance difference is large, the integration end judgment value is increased (judgment value 1).
→ Change the integration limit time 1 to a longer integration limit time 2 together with the judgment value 2).

Next, in step S311, the monitor output (A) of the selected line sensor is read.

Next, in step S312, the monitor output (A) is compared with the judgment value 2, and if the monitor output (A) exceeds the judgment value 2, the flow shifts to step S314.

Next, in step S313, if the monitor output (A) does not exceed the judgment value 2, the current integration time is compared with the newly set longer integration limit time 2, and the current integration time is compared. If the integration time exceeds the integration limit time 2, the process proceeds to step S314.

Next, in step S314, the integration of the line sensor ends.

Next, in step S315, a control signal is input to the control circuit 14 in the distance measuring sensor 11, and the charge stored in the photodiodes of the selected line sensors 12A, 12B, 12C is used as an image signal as an A / A signal. D-convert and read.

Next, in step S316, based on the pair of image signals from the line sensors 12A, 12B and 12C stored in the RAM, each of the line sensors 12A, 12
A defocus amount is calculated by calculating a pair of image intervals for each of B and 12C.

Next, in step S317, the defocus amount obtained for each line sensor is processed using a predetermined algorithm. For example, the closest defocus amount is selected and focusing is performed.

As described above, the main subject is reliably measured for a person whose background is a night scene or a backlit scene.
You can focus.

(Third Embodiment) Next, a description will be given of a third embodiment in which the distance measuring apparatus of the present invention is applied to an external light passive system.

FIG. 10 is a block diagram of a camera including a microcomputer 121 and a distance measuring sensor 111 constituting a distance measuring apparatus according to the third embodiment.

That is, as shown in FIG. 10, the distance measuring sensor 111 is provided with nine pairs of line sensors 112A to 112I.

Each of these line sensors 112A-112
I has processing circuit units 113A to 113I, respectively, and generates monitor outputs.

The control circuit 114 controls the operation of each unit in the distance measuring sensor 111 according to a control signal from the microcomputer 121.

The integration control circuit 118 is connected to the line sensor 11
Monitor outputs of 2A to 112C and 112G to 112I are input, and hard integration control is performed on these line sensors.

The monitor outputs of the line sensors 112D to 112F are input to the A / D conversion circuit 125 in the microcomputer 121 via the monitor output circuits 115A to 115C and the switch circuit 119, and the microcomputer 121 performs soft integration control. .

In the integration control circuit 118, the memory 13
1. A timer 132 is built in, and the measurement and recording of the integration time of each line sensor during the hard integration control are executed.

The microcomputer 121 controls each block as follows to control the operation of the entire camera.

The focus unit 141 performs focusing by driving the photographing lens 63 in the optical axis direction based on the result of the distance measurement.

The mode setting switch 142 is used to set a camera operation mode, such as a photographing mode and an AF mode, by a photographer's operation.

The photometric unit 145 measures the luminance of the subject and outputs it to the microcomputer 121.

The shutter unit 143 controls the shutter in accordance with the photometric value output from the photometric unit 145 and the conditions of the film sensitivity to perform exposure.

The film feeder 144 controls the automatic loading of the film, the winding of one frame after the photographing, and the rewinding.

1RSW 146 and 2RSW 147 are switches linked to the release button of the camera, respectively.
In the first release, the 1RSW 146 is turned on to perform photometry and distance measurement, and in the second release, the 2RSW 147 is turned on to perform focusing, exposure, and film winding.

As shown in FIG. 11, in front of the line sensors 112A to 112I in the distance measuring sensor 111, a pair of imaging lenses 61 and 62 as a distance measuring optical system are arranged.

The subject luminous flux incident on each of the imaging lenses 61 and 62 is substantially imaged on the line sensors 112A to 112I by the imaging lenses 61 and 62, respectively.

As described above, the external light passive system applied in the third embodiment measures the distance in a different optical path from that of the photographing lens 63.

The microcomputer 21 reads out the charge integrated by each photodiode of the line sensors 112A to 112I as an image signal, obtains an image interval on a pair of line sensors based on the image signal, and further forms imaging lenses 61 and 62. The subject distance is obtained by the principle of triangulation based on the base line length and the focal length.

The subject distance obtained for each line sensor is processed by a predetermined algorithm, and for example, the closest subject distance is selected and the camera is focused.

FIG. 12 shows the distance measuring areas 122A to 122I in the photographing screen 100 of the compact camera equipped with the above-mentioned external light passive type distance measuring device.

FIG. 15 is a flowchart for explaining the operation of the entire camera to which the third embodiment is applied.

When the power switch is turned on or a battery is inserted, the camera operation starts.

First, in step S501, 1RSWI
It is determined whether or not 46 is on, and if it is on, step S502
The process proceeds to step S503 if it is off.

Next, in step S502, the photometric unit 14
5 is performed.

Next, in step S503, it is checked whether or not a switch such as the mode setting switch 142 has been operated.

Next, in step S504, when any one of the switches such as the mode setting switch 142 is operated, an operation corresponding to the operation is performed.

Next, in step S505, a distance measuring operation by the distance measuring sensor 111 is performed.

Next, in step S506, 2RSW1
It is checked whether or not 47 has been turned on. If it is on, the process proceeds to step S506; if it is off, step S5 is performed.
10 and 2RSW14 while 1RSW146 is on
Wait for 7 to turn on.

Next, in step S507, the focus unit 141 drives the photographing lens 63 based on the distance measurement value to perform focusing.

Next, in step S508, the exposure is performed by controlling the shutter unit 143 based on the photometric value.

Next, in step S509, after the film is wound up by one frame by the film feeding unit 14, the process returns to step S501 to repeat the operation.

Next, the integration operation of the distance measuring sensor 111 will be described.

As shown in FIG. 12, in the distance measurement areas 122D to 122F at the center of the photographing screen, the existence probability of the main subject is high, and the priority is high.

On the other hand, as shown in FIG. 12, the distance measuring areas 122A to 122C and 122G to 122
1 has a low probability of existence of the main subject and a low priority,
Controlled by hardware integration control.

The integration time of the line sensor when performing the hard integration control is determined by the timer in the integration control circuit 118.
Measurement is performed by 132 and the integration time data is stored in the memory 131 in the distance measuring sensor 11.

Then, the microcomputer 121 operates the distance measuring sensor 1.
Through the communication with the controller 11, the integration time by the hard integration control is read from the memory 131.

This integration time is used, for example, as data for judging whether or not to irradiate AF auxiliary light.

Next, with reference to a flowchart shown in FIG. 14, a description will be given of a point at which the integration control mode is switched depending on the photographing mode and AF mode of the camera.

First, in step S401, it is determined whether the mode is the moving object prediction mode, the continuous AF mode, or the continuous shooting mode, and if so, step S402.
Otherwise, to step S403.

Next, in step S402, in the moving object prediction mode, the continuous AF mode, the continuous shooting mode, and the like, a relatively bright object is targeted, and high-speed processing is required as a distance measuring device. It is assumed that there are distance measurement areas 122D to 122F (line sensors 112D to 11D).
The mode is also switched to the hard integration control mode for 2F).

In response to a command from the microcomputer 121, the control circuit 114 turns on the switch group of the switch circuit 140 and turns off the switch group of the switch circuit 119, and performs hard integration control by the integration control circuit 118.

Next, in step S403, in the case of the normal photographing mode other than the above, the distance measuring areas 122D-1
22F is a soft integration control mode.

Next, in step S404, the integral control according to the integral control mode by the hard integral control or the soft integral control is performed.

Next, in step S405, when the integration is completed, the image signal is read.

Next, in step S406, a distance measurement calculation is performed, and the routine returns.

As described above, in the distance measuring apparatus according to the third embodiment, since the microcomputer 121 and the integration control circuit 118 share the integration control of a large number of line sensors, even a relatively low-speed and low-cost microcomputer can be used. The distance measurement accuracy of the important distance measurement area can be ensured.

Note that the line sensors 112A to 112C may be used by dividing one line sensor.

This corresponds to the line sensors 112D to 112D.
The same applies to F, 112G to 112I.

In the case where the distance measuring sensor is configured to be able to switch between the hard integration control mode and the soft integration control mode for all the distance measurement areas (line sensors), it is effective to perform the following control. .

That is, when the photographing mode is set to the night scene portrait mode for photographing a person with a night scene as a background, the soft integration control mode is performed for all the distance measurement areas.

In this case, since the subject brightness is relatively low and high-speed integration control is not required, the main subject can be accurately focused by the above control.

In the passive distance measuring apparatus according to the present invention, it is possible to obtain an appropriate image signal in all photographing scenes at low cost.

The present specification described in the above-described embodiments includes the inventions shown below as supplementary notes 1 to 5.

(Supplementary Note 1) In the distance measuring apparatus, the subject light is received by a light receiving means having a plurality of light receiving elements, and a defocus amount or a distance to the subject is measured based on an integrated output from the light receiving means. Comparing a monitor output indicating an integration state generated by the light receiving means with a predetermined value, and determining that the monitor output has exceeded the predetermined value, first integration control means for terminating the integration operation of the light receiving means; Referring to the monitor output indicating the integration status generated from the light receiving means, it is determined whether or not the integration operation by the light receiving means is performed at a proper integration level. When it is determined that the operation is performed at the level, the second integration control means for terminating the integration operation of the light receiving means, the first integration control means, and the second integration control means are switched. And a control means that is effective.

(Supplementary Note 2) The light receiving means includes a plurality of light receiving means each provided with a plurality of light receiving elements, and the first integration control means and the first integration controlling means are provided for each of the plurality of light receiving means. The distance measuring apparatus according to claim 1, wherein the second integral control means can be selected.

(Supplementary Note 3) The first integration control means and the second integration control means are provided with respect to the light receiving means.
3. The distance measuring apparatus according to claim 1, wherein the switching is performed according to an integration time, an operation mode, and a distance measuring area position.

(Supplementary Note 4) The first integral control means is
4. The distance measuring device according to any one of supplementary notes 1 to 3, further comprising a comparison circuit.

(Supplementary Note 5) The second integration control means
Supplementary notes 1 to 3 characterized by having an A / D conversion circuit
3. The distance measuring device according to 1.

[0179]

Therefore, as described above, according to the present invention, a passive distance measuring system having a charge accumulation type sensor and capable of obtaining an appropriate integrated signal in all photographing scenes at low cost. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main circuit configuration of a passive distance measuring apparatus applied as a first embodiment of the present invention.

2 (a) and 2 (b) are distance measuring sensors 1 of FIG. 1;
FIG. 1 is a diagram illustrating a configuration of a camera and a distance measuring optical system when 1 is applied to a TTL passive system of a single-lens reflex camera.

FIG. 3 is a distance measurement area 112A, 112B, 112 in a photographing screen 100 of the single-lens reflex camera of FIG. 2;
It is a figure showing C.

FIG. 4 is a diagram showing a microcomputer 21 in the distance measuring apparatus shown in FIG. 1;
6 is a flowchart for explaining a distance measuring operation according to the first embodiment.

FIG. 5A shows the level of the comparison determination value of the monitor output in the hard integration control mode, and FIG.
FIG. 7 is a diagram showing the level of a comparison determination value of a monitor output in a soft integration control mode.

FIG. 6 shows a second embodiment of the present invention.
FIG. 7 is a diagram showing that when the luminance difference between line sensors is large, it can be estimated that the subject as shown in FIG. 6 is likely to be a person with a night view as a background or a backlight scene.

FIG. 7 is a flowchart for explaining a distance measuring operation according to the second embodiment.

FIG. 8 is a diagram showing a microcomputer 21 in the distance measuring apparatus shown in FIG. 1;
6 is a time chart for explaining a distance measuring operation according to FIG.

9 shows that the integration control circuit 18 in the distance measuring apparatus of FIG. 1 has built-in comparators 41, 42, and 43 for comparing the judgment voltage Vth with the monitor outputs A, B, and C. FIG.

FIG. 10 is a diagram illustrating a distance measuring sensor 111 and a microcomputer 121 included in a distance measuring apparatus according to a third embodiment of the present invention.
It is a block diagram of a camera including.

11 is a diagram showing a state in which a pair of imaging lenses 61 and 62 as a distance measuring optical system is disposed in front of line sensors 112A to 112I in the distance measuring sensor 111 in FIG. is there.

FIG. 12 is a distance measurement area 122A-1 in a photographing screen 100 of a compact camera equipped with an external light passive distance measurement apparatus applied to the third embodiment of the present invention;
It is a figure which shows 22I.

FIG. 13 is a time chart for explaining a distance measuring operation according to the second embodiment.

FIG. 14 is a flowchart for explaining a point of switching an integration control mode depending on a shooting mode and an AF mode of a camera to which the third embodiment is applied;

FIG. 15 is a flowchart for explaining the operation of the entire camera to which the third embodiment is applied;

[Explanation of symbols]

11, 111: distance measuring sensor, 12A, 12B, 12C, 112A to 112I: line sensor, 13A, 13B, 13C, 113A to 113I: processing circuit section, 21, 121: microcomputer (microcomputer), 22: ROM, 14 , 114 ... control circuit, 15A, 15B, 15C, 115A, 115B, 115
C: output circuit, 25, 125: A / D conversion circuit, 23: RAM, 18, 118: integration control circuit, 119: switch circuit, 16A, 16B, 16C: monitor circuit, 44: judgment voltage generation circuit, 41, 42, 43: comparator, 26: timer counter, 28: oscillation circuit, 27: memory, 71: photographing lens, 72: main mirror, 74: finder optical system, 73: sub-mirror, 78: distance measuring unit, 75: screen 76, a center prism, 77, an eyepiece, 79, a film, 71a, 71b, a predetermined area of the photographing lens 71, 51, a field mask, 51A, 51B, 51C, an opening 52, a condenser lens, 53, 54, a pair Separator lens, 100: shooting screen, ranging area: 112A, 112B, 112C, 131: memory, 132: timer, 141: focus unit, 63: photographic lens, 142: mode setting switch, 145: photometric unit, 143: shutter unit, 144: film feed unit, 146: 1RSW, 147: 2RSW.

Claims (3)

[Claims] 1. A distance measuring device for receiving subject light by a light receiving means having a plurality of light receiving elements and measuring a defocus amount or a distance to the subject based on an integrated output from the light receiving means. A first integral control means for terminating the integration operation of the light receiving means when it is determined that the monitor output has exceeded the predetermined value; It is determined whether or not the integration operation by the light receiving means is performed at a proper integration level with reference to the monitor output indicating the integration status generated by the light receiving means. If it is determined that the operation is being performed by the first integration control means, the second integration control means for terminating the integration operation of the light receiving means, the first integration control means, and the second integration control means are switched to be effective. A distance measuring device, comprising: control means; 2. The light-receiving means includes a plurality of light-receiving means each including a plurality of light-receiving elements, and each of the plurality of light-receiving means has a first integration control means and a second light-receiving element. 2. A distance measuring apparatus according to claim 1, wherein said integration control means can be selected. 3. The method according to claim 1, wherein the first integration control means and the second integration control means are provided with an integration time,
The distance measuring apparatus according to claim 1, wherein the switching is performed in accordance with an operation mode and a distance measuring area position.