JP2002328296A - Range finder of camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a release time lag in performing range finding with high accuracy with a range finder of a small-sized camera with which high- accuracy range finding of a photographic range is possible. SOLUTION: This range finder of the camera has integrating photodetecting means 1 which performs the range finding of a subject, ordinary ray removing means 2 which is built into the integrating photodetecting means 1, first illumination means 3 which illuminates the photographic range, second illumination means 4 which illuminates a portion of the photographic range, integrating mode changeover means 5 which set plural integrating modes for on/off control of the ordinary ray removing means 2 and the first and second illumination means 3 and 4, range finding history memory means 6 which stores the range finding data subjected to range finding computation by the integrating mode set by the integrating mode changeover means 5, clocking means 7 which measures the range finding intervals of the previously time and the next time and range finding procedure changing means 8 which changes the setting of the integrating mode changeover means 5 by changing over the means in accordance with the range finding history stored in the range finding history memory means 6 from the ordinary integrating mode when the measurement time of the clocking means 7 is below the prescribed time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device for a camera, and more particularly, to a distance measuring device for a camera which illuminates a subject and measures a distance as required.

[0002]

2. Description of the Related Art Conventionally, various distance measuring methods have been proposed for a camera distance measuring apparatus. The distance measuring methods include a triangulation method and a propagation time detecting method. In these methods, the camera used is mainly a triangulation method. This triangulation method can be further roughly classified into a passive method and an active method.

[0003] The passive type distance measuring device is, for example,
It has a pair of line sensors that separate and receive light from a subject and convert them into respective subject image signals. Further, when the brightness or contrast of the subject is low, an auxiliary light source such as a strobe that irradiates the subject with illumination light may be provided.

In the passive method, when a subject is bright and has sufficient contrast, distance measurement can be performed with high accuracy even for a distant subject. Furthermore, while distance measurement can be performed over a wide range in the shooting screen, when the subject is dark or the contrast is low, it is difficult to perform accurate distance measurement unless the illumination by the auxiliary light source is sufficient. I will.

The active type distance measuring device is
For example, an infrared light emitting element (hereinafter, referred to as an infrared LED) that projects an infrared beam light toward a subject, and the infrared LE
D and a position detecting element that has a base line length and receives reflected light from a subject irradiated with the infrared beam light.

This active method basically emits infrared light in the form of a beam, so that distance measurement can be performed even when the subject itself has almost no contrast. It is difficult to accurately measure the distance of a subject as far as infrared light cannot reach, and it is only possible to measure the distance of a subject located near the center of the shooting screen.

[0007] These passive system and active system,
It can be said that there is a complementary relationship in which one disadvantage is the other. Thus, a high-performance hybrid type distance measuring device in which the passive method and the active method are combined and one disadvantage is compensated for by the other advantage has been put into practical use in recent years.

The hybrid type distance measuring device has, for example, a pair of line sensors and light projecting means, and its basic configuration is almost the same as the basic configuration of the passive type distance measuring device. In addition, the calculation performed when obtaining the subject distance also uses the phase difference calculation (correlation calculation) as in the passive rangefinder.

The hybrid system differs from the passive system in that a stationary light removing circuit is added to each pixel constituting the line sensor. That is, this hybrid type distance measuring device can function as a passive type distance measuring device by turning off the stationary light removing circuit and not driving it, and driving the stationary light removing circuit on. Thereby, it can function as an active type distance measuring device.

When the stationary light removing circuit is turned on to function as an active type distance measuring device, an infrared LED is used.
The infrared light projected from the light projecting means is reflected by the subject and is incident on the line sensor. By removing the stationary light component by the stationary light removing circuit from the photoelectric current output from each pixel of the line sensor on which the reflected light from the subject is incident, only the infrared light component illuminated by the infrared LED is removed. Can be taken out. The subject distance can be obtained by performing a phase difference calculation (correlation calculation) based on the subject image signal based on the photocurrent of the infrared light.

In the hybrid type distance measuring apparatus as described above, the sensor is of course the most important factor for determining the performance, but the next most important factor is the light projecting means. An ideal light projecting means is provided with a light projecting element capable of irradiating a large amount of pattern with a large amount of light.

[0012]

However, the above-mentioned ideal light projecting means, that is, a light projecting means capable of irradiating a large amount of pattern with a large amount of light and which is small enough to be mounted on a camera, is not available at present. Unfortunately does not exist.

Therefore, it is necessary to separately provide a light projecting means, or it is necessary to mount the camera with a small amount of light. In this case, a distance measurement procedure (integration mode) including control of the driving of the steady light removing circuit and the driving of the projection element according to the subject is set, thereby enabling highly accurate distance measurement.

However, while accurate distance measurement is possible, the distance measurement procedure (integration mode) is very complicated, and the release time lag that increases the time required for distance measurement increases. The increase in the release time lag is a serious problem for a user to miss a photo opportunity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a compact camera distance measuring apparatus capable of minimizing a release time lag and enabling highly accurate distance measurement in a wide photographing range. And

[0016]

A distance measuring apparatus for a camera according to the present invention integrates a photocurrent due to incident light from a subject to generate a subject image signal, and calculates distance measurement data from the subject image signal. Integral light receiving means, a stationary light removing means for removing a stationary light component from the photocurrent generated by the integrating light receiving means, and a first illuminating means for illuminating a range including at least a camera shooting range, A second illuminating unit that illuminates a partial range included in the photographing range of the camera, driving / non-driving of the stationary light removing unit, driving / non-driving of the first and second illuminating units, and When driving the first and second illuminating means, switching is performed to determine which of the first and second illuminating means is driven, and the like, and an integration mode for setting a plurality of integration modes of the integrating light receiving means Switching means and switching of the integration mode Distance measurement history storage means for storing the distance measurement history data such as the distance measurement data calculated in the integration mode, the distance measurement operation, and the next distance measurement operation from the previous distance measurement operation Time measuring means for measuring the elapsed time until, and when the elapsed time measurement result of the time measuring means is less than a predetermined time, from the normal integration mode, based on the distance measurement history stored in the distance measurement history storage means. And a distance measurement procedure changing means for switching and changing the setting of the integration mode switching means.

Further, the first illuminating means of the camera distance measuring apparatus of the present invention is a strobe which also serves as an illuminating means at the time of photographing, and the second illuminating means is an illuminating means for emitting infrared light. It was characterized by being.

According to the distance measuring device of the present invention, the distance measuring time is set in order to set the integration mode for the next distance measurement based on the previous integration mode and the distance measurement data stored in the distance measurement history storage means. Shortening was possible and the release time lag was shortened.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of a camera distance measuring apparatus according to the present invention.
4 is a flowchart for explaining a normal distance measuring operation of the camera distance measuring apparatus of the present invention. FIG. 3 is an explanatory diagram for explaining a distance measuring sequence mode of the camera distance measuring apparatus of the present invention.
5 is a flowchart for explaining a distance measuring sequence operation other than the normal distance measuring operation.

As shown in FIG. 1, a distance measuring device for a camera according to the present invention comprises a line sense, and integrates a photocurrent generated by incident light from a subject to generate and output a subject image signal. And a passive integration mode which is built in the integrating type light receiving means 1 and which is in a non-driving state when it is controlled to be off, is a first integration mode, and which is in a driving state when it is controlled to be in an active state which is a second integration mode. A stationary light removing unit 2 for switching to a mode, a first illuminating unit 3 which is a unit for illuminating a subject at the time of photographing by the camera, and also serves as a unit for irradiating an auxiliary light at the time of distance measurement; It is comprised of a second illuminating means 4 which is included in the range and is a light projecting means for irradiating a part of a narrower range, and a microprocessor (CPU) 13.

The integration type light receiving means 1 is, for example, an automatic focusing IC (AFIC) and has a pair or a plurality of pairs of line sensors or area sensors. The first illuminating means 3 is constituted by a strobe or the like capable of irradiating a large area including at least a photographing range of a camera with a large amount of light.
, And an optical system capable of at least one of spot irradiation and pattern irradiation.

The stationary light removing means 2 causes the integral light receiving means 1 to perform a switching function as an active or passive distance measuring device. The general illumination light is removed, and a subject image signal is generated by the integration type light receiving unit 1 by infrared light projected from the second lighting unit 4 and reflected by the subject.

The CPU 13 includes a light / dark judging means 9 for judging the brightness of a subject, and the stationary light removing means 2, the first lighting means 3 and the second lighting means 3 based on the light / dark judgment output of the light / dark judgment means 9. An integration mode switching means 5 for switching the driving operation of the illumination means 4 to switch the distance measurement integration mode, and calculating the distance to the subject from the subject image signal obtained by the integration type light receiving means 1 by a known calculation method. Computing means 10 for performing
The distance measurement data calculated by the calculation means 10 is compared and determined with a predetermined reference value. As a result of the comparison, the distance measurement invalidity determination means 11 determines whether or not the data cannot be measured. A light emission inhibiting means 1 for operating the input means or for setting the first lighting means 3 to a strobe off mode under the control of a distance measuring procedure changing means 8 which will be described later.
2, the distance measurement integration mode set by the integration mode switching means 5, and the subject image signal generated by the integration type light receiving means 1 in the distance measurement mode set by the integration mode switching means 5. Distance measurement history storage means 6 for storing the distance measurement data calculated by the calculation means 10; integration mode switching means 5 based on the distance measurement integration mode and the distance measurement data stored in the distance measurement history storage means 6; And a time measuring means 7 for measuring the elapsed time from the previous distance measuring operation.

The light / dark judging means 1 is a light-receiving element for photometry of a subject (not shown) and the brightness of the subject based on a subject light signal supplied from a photometry circuit (not shown) for processing the output of the light-receiving element. Judge. Also, instead of the photometric element and the photometric circuit, the progress speed of the integration process from the integrating type light receiving means 5 may be monitored to determine the brightness.

Next, a normal distance measuring operation of the distance measuring apparatus for a camera according to the present invention will be described with reference to FIG. When the photographer operates a release switch (not shown) or the like to photograph a subject, photometry and distance measurement of the subject are performed as a photographing preparation operation of the camera.

When the release switch is turned on, in step S1, the CPU 13 performs subject photometry on the basis of the subject light received by the above-mentioned photometric device (not shown) or the integral type light receiving means 1, and the CPU 13 performs the subject photometry. The photometric result is output to the light / dark determination means 9. Next, in step S2, it is determined whether the brightness of the subject is higher or lower than a predetermined brightness based on the photometric result of the subject light output to the light / dark determining means 9. Note that the brightness of the subject is determined by C
It is stored in advance in a non-volatile storage unit (not shown) provided inside the PU 13 or another non-volatile storage unit (not shown) provided outside the CPU 13.

If it is determined in step S2 that the subject is brighter than the predetermined brightness, information that the brightness of the subject is bright is transmitted to the integration mode switching means 5, and in step S3, the integration mode Switching means 5
Switches to the integration mode in which the first lighting means 3, the second lighting means 4, and the steady light removing means 2 are all turned off.

That is, the integration mode in step S3 is set to a passive mode in which the distance measuring device of the camera measures the distance to the object without auxiliary light.

When the passive mode is set in step S3, in step S4 the subject light incident on the integral type light receiving means 1 is photoelectrically converted and integrated to generate a subject image signal. Based on the subject image signal, a correlation operation is executed by the operation means 10 in step S5. This correlation calculation is a known technique. For example, in the case of multi-auto focus, the correlation calculation is performed on a plurality of distance measurement areas to select the closest distance.

When the correlation calculation in step S5 is completed, the calculation result is supplied to the ranging error determination means 11, and the reliability of the correlation calculation result is determined in step S6. This reliability determination is also a known technique, and in the case of the multi-automatic focus, the reliability determination regarding the correlation calculation of the closest selected ranging area is executed.

In step S6, if it is determined that the correlation calculation result is reliable and the measured distance data is normal, the ranging error determination means 11 determines whether the calculation result by the calculation means 10 is correct. Is output to the focusing drive function of the photographing lens (not shown) as subject distance information, and then the normal distance measurement processing is terminated.

On the other hand, in step S6, when it is determined that the distance calculation is not possible due to the unreliability of the correlation calculation result, that is, an object of a type that is bright but difficult to measure the distance in the passive mode, for example, contrast. This is a case of a subject having almost no.

Since this subject is a bright subject with little contrast, the result of the correlation calculation is not reliable.
If it is determined in step S6 that the distance measurement data is abnormal, the result of the determination is transmitted to the integration mode switching means 5 via the arithmetic means 10, and in step S9 the integration mode switching means 5 Integration mode switching is performed in which one lighting means 3 is turned off, the second lighting means 4 is turned on, and the stationary light removing means 2 is turned on. This allows the camera's ranging device to
The mode is set to the active mode using the auxiliary light from the second illuminating means 4 and emitted from the infrared LED or the like.

When the active mode is set in step S9, the integrating type light receiving means 1 reflects the infrared auxiliary light projected from the second illuminating means 4 from the subject, and Based on the subject light incident on the device, photoelectric conversion and integration are performed in the same manner as in step S4 to generate an infrared subject image signal. Based on the infrared integrated subject image signal, the process proceeds to step S11. Similar to S5, the calculation means 10 executes the correlation calculation. Further, in step S12, similarly to step S6, the ranging error determination means 11 determines the reliability of the ranging data obtained by the correlation calculation.

If it is determined in step S12 that the distance measurement data is normal, the process proceeds to step S6.
In the same manner as in the case where it is determined that the distance can be measured, the illegal distance measurement determining means 11 permits the result calculated by the calculating means 10 in step S11 to be output as subject distance information. The distance measurement processing ends.

If it is determined in step S12 that the distance cannot be measured, the object distance information is set to infinity or a long distance including infinity within the depth of field in step S13. Then, the normal distance measurement processing ends.

When the subject is bright, such an operation is performed. On the other hand, when the subject is dark, the following operation is performed.

That is, if it is determined in step S2 that the subject is darker than the predetermined luminance, it is determined in step S7 whether the light emission inhibiting means 12 inhibits light emission of the first lighting means 3. Is determined. That is, the operation mode of the camera is determined to determine whether or not the camera is in the strobe off mode.

If the light emission of the first lighting means 3 is not prohibited in step S7, the integration mode switching means 5 turns on the first lighting means 3 in step S8, 4 is turned off, and the steady light removing means 2 is turned on. As a result, the distance measuring device of the camera is set to the active mode using the auxiliary light by the strobe or the like.

When this step S8 is completed, the process proceeds to step S4 to perform the above-described operation.

If the light emission of the first illuminating means 2 is prohibited in step S7, the process proceeds to step S9 to use the auxiliary light by the infrared LED or the like as described above. Performs ranging in active mode.

In the normal distance measuring operation described above, the integration modes set by the integration mode switching means 5 in steps S3, S8 and S9 are arranged as shown in FIG.

That is, the first lighting means 3 in step S3,
The integration mode for measuring the distance in the passive mode in which both the second illuminating means 4 and the stationary light removing means 2 are off is represented by a sequence A.
The sequence B is an integration mode for performing distance measurement in the active mode in which the first illuminating means 3 is on, the second illuminating means 4 is off, and the steady deduction means 2 is on in step S8, and the first illumination in step S9. The sequence C is an integration mode in which the distance is measured in the active mode in which the means 3 is off, the second illumination means 4 is on, and the steady deduction means 2 is on.

When each of the sequences A, B, and C is driven, the result of the distance measurement data in step S6 or S12 for each of the sequences A to C is divided into "normal" and "abnormal". By the determination of the distance measurement data, the sequence of the next distance measurement operation can be set.

That is, if the result of the distance measurement data determination in the sequence A is "normal", the next distance measurement operation becomes operable in the sequence A, and if it is determined to be "incorrect", the next distance measurement operation is performed. Is operated in sequence B.
If the result of the ranging data result determination in the sequence B is "normal", the next ranging operation can be performed in the sequence B, and if the determination is "incorrect", the next ranging operation is performed in the sequence C. Will be. Further, if the result of the distance measurement data determination in the sequence C is "normal", the next distance measurement operation becomes operable in the sequence C, and if it is determined to be "incorrect", the next distance measurement operation is performed in the sequence A. Can be operated.

FIG. 3 shows that the first lighting means 3
Is on, the second lighting means 4 is off, and the steady light removing means 2
D, the sequence E in which the first lighting means 3 is off, the second lighting means 4 is on, and the sequence E in which the stationary light removing means 2 is off, the first lighting means 3 is off, and the second lighting means 4 is A sequence F in which the off-state and the stationary light removal distance means 2 are on is considered. Note that the operations of the sequences DF are not shown in FIG.

The distance measuring operation according to the distance measuring operation sequences A to F will be described with reference to FIG. FIG. 4 illustrates the ranging operation by the ranging sequences A to C.

When the photographer operates a release switch (not shown) or the like to photograph a subject, subject distance measurement and photometry are performed as a photographing preparation operation of the camera.
At this time, the distance measuring operation is performed by turning on the release switch in step S21.
It is determined whether this is the first distance measurement at the time of shooting. If it is determined that the distance measurement is the first distance measurement, the normal distance measurement operation described with reference to FIG. 2 is started and executed in step S22. This step S
The distance measurement sequence and the distance measurement data executed in the normal distance measurement operation 22 are stored in the distance measurement history storage means 6 in step S23, and the normal distance measurement operation ends.

If it is determined in step S21 that the distance measurement is not the first distance measurement, the elapsed time interval between the previous distance measurement and the current distance measurement is measured by the timer 7 in step S24. If it is determined that the time interval between the previous distance measurement and the current distance measurement measured by the timer 7 has exceeded a predetermined time, the normal distance measurement in step S22 is executed.

That is, the fact that the current distance measurement operation is performed after a predetermined time has elapsed since the previous distance measurement means that the subject conditions are different between the previous distance measurement (previous shooting) and the current distance measurement (current shooting). Since it is not possible to refer to the distance measurement sequence and the data at the time of the previous distance measurement, the distance measurement is newly performed by the normal distance measurement in the distance measurement sequence suitable for the subject condition.

If it is determined in step S24 that the distance measurement interval time is within the predetermined time, the distance measurement sequence stored in the distance measurement history storage means 6 at the previous distance measurement is A in step S25. If it is determined by the distance measurement procedure changing means 8 that it is the distance measurement sequence A (see FIG. 3), then in step S26, the previous distance measurement data stored in the distance measurement history storage means 6 is obtained. The result is determined by the distance measurement procedure changing means 8 as to whether the result is “normal” or “abnormal”.

If the result of the previous distance measurement data is "normal",
As shown in FIG. 3, the operation condition in which all of the first illuminating means 3, the second illuminating means 4, and the steady light removing means 2 of the sequence A, which is the same condition as the previous distance measuring sequence in step S27, is turned off. The setting is made by the integration mode switching means 5 via the distance measurement procedure changing means 8.

FIG. 3 shows the case where the result of the previous distance measurement is "abnormal".
As shown in step S28, the operation conditions for turning on the first lighting means 3, turning off the second lighting means 4, and turning on the steady light removing means 2 in the sequence B different from the round sequence in step S28 are changed to the distance measuring procedure changing means. 8 through the integration mode switching means 5.

When the setting of any one of the distance measuring sequences in steps S27 and S28 is completed, steps S36 and thereafter are executed.

If it is determined in step S25 that the distance measurement sequence at the time of the previous distance measurement stored in the distance measurement history storage means 6 is not A, the distance measurement procedure change means 8 determines in step S29. The previous distance measurement sequence stored in the distance measurement history storage means 6 is determined to be B or not by the distance measurement procedure changing means 8, and if it is determined to be sequence B, the distance measurement history is determined in step S30. It is determined whether the result of the distance measurement data of the sequence B stored in the storage means 6 is “normal” or “abnormal”.

If the result of the previous distance measurement data is "normal",
As shown in FIG. 3, in step S31, an operating condition of the sequence B, which is the same condition as the previous ranging sequence, in which the first lighting means 3 is on, the second lighting means 4 is off, and the steady light removing means 2 is on. Via the distance measurement procedure changing means 8
It is set by the integration mode switching means 5.

If the result of the previous distance measurement data is "abnormal", as shown in FIG. 3, in step S32, the first illuminating means 3 of the sequence C different from the round sequence is turned off and the second illuminating means 4 is turned on. The operating condition for turning on the steady light removing means 2 is set by the integration mode switching means 5 via the distance measurement procedure changing means 8.

When the sequence setting of any one of steps S31 and S32 is completed, steps S36 and thereafter are executed.

In step S25, the previous sequence is not A, and in step S29, the previous sequence is B.
If the distance measurement procedure changing means 8 determines that the previous sequence is not the same, the previous sequence is determined to be C (see FIG. 3), and in step S33, the previous distance measurement stored in the distance measurement history storage means 6 is performed. The data result is determined by the distance measurement procedure changing means 8 as to whether the data is "normal" or "abnormal".

If the result of the previous distance measurement data is "normal",
As shown in FIG. 3, in step S34, operating conditions in which the first illuminating means 3 is off, the second illuminating means 4 is on, and the stationary light removing means 2 is on in sequence C, which is the same condition as the previous ranging sequence. Via the distance measurement procedure changing means 8
It is set by the integration mode switching means 5.

If the result of the previous distance measurement data is "abnormal", as shown in FIG. 3, in step S35, the first illuminating means 3, the second illuminating means 4, and the steady light removing means of the sequence A different from the previous sequence are used. The operating conditions for turning off both 2 are set by the integration mode switching means 5 via the distance measurement procedure changing means 8.

When the sequence setting in any of steps S34 and S35 is completed, step S36 and subsequent steps are executed.

Steps S27, S28, S31, S
When any of the sequence conditions is set in steps S32, S34, and S35, in step S36, the integration type light receiving unit 1 is set.
A subject image signal is photoelectrically converted and integrated to generate a subject image signal. Based on the integrated subject image signal, a correlation operation is executed by the calculating means 10 in step S37. This correlation calculation is a known technique. For example, in the case of multi-auto focus, the correlation calculation is performed on a plurality of distance measurement areas to select the closest distance.

When the correlation calculation in step S37 is completed, the calculation result is supplied to the ranging error determination means 11, and in step S38, the reliability of the distance measurement data as a result of the correlation calculation is determined. This reliability determination is also a known technique, and in the case of the multi-automatic focus, the reliability determination regarding the correlation calculation of the closest selected ranging area is executed.

In step S38, if it is determined that the correlation calculation result is reliable and the distance measurement data is "normal", the ranging error determination means 11 determines whether the calculation result by the calculation means 10 is correct. Is output to the focusing drive function (not shown) of the photographing lens as subject distance information, and the distance measurement sequence and the distance measurement data of the distance measurement result are stored in the distance measurement history storage unit 6 in step S23.
After that, the distance measurement processing ends.

If it is determined in step S38 that the correlation calculation result is "abnormal", then in step S39,
The subject distance information is set to infinity or a long distance including infinity within the depth of field, and in step S23, the distance measurement sequence and the subject distance information are set to infinity or infinity to depth of field. After the data set to the long distance included in the data is stored in the distance measurement history storage means 6, the distance measurement processing operation is terminated.

As described above, the range finder for a camera according to the present invention is capable of irradiating a large area with a large amount of light by a strobe or the like, and capable of performing pattern irradiation or spot irradiation in a narrow area. High-accuracy ranging under a wide range of conditions of the subject by selectively using the second illuminating hand using a simple infrared LED and the stationary light removing means provided in the integrating light receiving means In addition, by storing the subject ranging conditions at the time of the previous shooting, the distance measurement driving is performed under the previous ranging conditions stored at the time of the next shooting and ranging, so that the release time lag can be reduced.

The present invention is not limited to the above-described embodiment, and various modifications and applications can be made without departing from the gist of the invention.

[0069]

As described above, according to the camera distance measuring apparatus of the present invention, it is possible to perform high-precision distance measurement under a wide range of subject conditions while maintaining a small size, and a distance measuring method at the time of shooting. By storing the distance measurement data and the distance measurement data, it is possible to execute the distance measurement based on the previous distance measurement method and the distance measurement data stored at the next shooting, so that the time required for the distance measurement is reduced, that is, the release time lag is reduced. This makes it possible to take a subject intended by the photographer without missing a photo opportunity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a camera distance measuring apparatus according to the present invention.

FIG. 2 is a flowchart illustrating a normal ranging operation of the ranging device for a camera according to the present invention.

FIG. 3 is an explanatory diagram illustrating a ranging sequence mode of the ranging device of the camera according to the present invention.

FIG. 4 is a flowchart illustrating a ranging sequence operation other than the normal ranging operation of the ranging device for a camera according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Integrating light receiving means 2 ... Steady light removing means 3 ... First illuminating means 4 ... Second illuminating means 5 ... Integration mode switching means 6 ... Distance measuring history storage means 7 ... Time measuring means 8 ... Distance measuring procedure changing means 9 ... Brightness / darkness determination means 10 ... Calculation means 11 ... Distance measurement impossible determination means 12 ... Light emission prohibition means 13 ... Microprocessor (CPU)

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) G03B 15/05 G03B 3/00 A F term (reference) 2H002 DB20 FB29 FB31 GA24 GA54 HA04 HA05 ZA03 2H011 AA01 BA01 BA11 DA00 DA08 2H051 AA01 BB01 BB11 CB20 CC11 CC18 DA02 EB00 2H053 BA75 BA82

Claims (2)

[Claims] 1. An integrated light receiving means for integrating a photocurrent due to incident light from a subject to generate a subject image signal and calculating distance measurement data from the subject image signal; Stationary light removing means for removing a steady light component from a photocurrent to be emitted; first lighting means for illuminating at least a range including a shooting range of the camera; and a partial range included in the shooting range of the camera. A second illuminating means for illuminating, a driving / non-driving of the stationary light removing means, a driving / non-driving of the first and second illuminating means, and a driving of the first and second illuminating means. An integration mode switching means for switching which of the first and second illumination means is driven, and setting a plurality of integration modes of the integration type light receiving means; and an integration set by the integration mode switching means. Mode and its integration mode Distance measurement history storage means for storing distance measurement history data such as distance measurement data calculated by distance measurement; time measurement means for measuring an elapsed time from the previous distance measurement operation to the next distance measurement operation; When the elapsed time measurement result of the time counting means is less than a predetermined time, the integration mode switching means is switched and changed from the normal integration mode based on the distance measurement history stored in the distance measurement history storage means. A ranging device for a camera, comprising: means for changing a ranging procedure. 2. The apparatus according to claim 1, wherein said first illuminating means is a strobe which also serves as an illuminating means at the time of photographing, and said second illuminating means is an illuminating means for emitting infrared light. 1
A distance measuring device for a camera according to item 1.