JP2003279837A - Light reception sensor for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light reception sensor for a camera capable of providing a small-sized composite sensor unit for the camera capable of coping with various photographing scenes by enabling stable range finding regardless of luminance or distance and fetching the functions of various kinds of sensors into one unit. <P>SOLUTION: In the light reception sensor for the camera having a pair of line sensors 14a and 14b for detecting a light distribution from an object 1 through light reception lenses 13a and 13b, the currents of respective pixel output constituting the line sensors 14a and 14b are led to a first or second circuit by a switch part 15. The first circuit includes an integration decision part 17 for forming image signals by the pixel output. In the meantime, the second circuit includes an addition circuit 19 for adding the pixel output currents and forming signals indicating the output of the total sum of a prescribed pixel block. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for a camera, and more particularly, to improvement of a distance measuring device, an exposure sensor, and a remote controller sensor used in an autofocus (AF) camera or the like. .

[0002]

2. Description of the Related Art The AF technology of a camera can be roughly divided into two types. There are two methods: a passive type that uses a subject image and an active type that uses distance measuring light projected from the camera.

However, each of these methods has drawbacks based on the principle of the method. Therefore, for example, as disclosed in JP-A-63-49738,
Various AF methods combining both methods have been proposed as a hybrid method or a combination method.

In recent years, more and more cameras are provided with a remote control signal receiving portion for remote operation and a photometric sensor for exposure control of a complicated division pattern.
JP-A-9-61932 and the like are known.

[0005]

However, the above-mentioned Japanese Patent Application Laid-Open No. 9-61932 has not described in detail the specific circuit control.

The present invention has been made in view of the above problems, and enables stable distance measurement regardless of brightness and distance, and by incorporating the functions of various sensors into one unit, various shooting scenes can be performed. It is an object of the present invention to provide a light receiving sensor for a camera, which can provide a small-sized composite sensor unit for a camera that can handle the above.

[0007]

That is, the present invention provides a camera light-receiving sensor having a pair of light-receiving sensor rows for detecting a light distribution from a subject through a pair of light-receiving lenses. Switch means for guiding an individual pixel output current to the first or second circuit, the first circuit including an integrating circuit for forming an image signal from the pixel output, and the second circuit. Includes an adder circuit that adds the pixel output currents and forms a signal representing the output of the sum of a predetermined pixel block.

According to the present invention, in a light receiving sensor for a camera having a pair of light receiving sensor rows for detecting a light distribution from a subject through a pair of light receiving lenses, each pixel forming the sensor row is described. The output current is guided to the first or second circuit by the switch means. The first circuit is configured to include an integrating circuit for forming an image signal from the pixel output, and the second circuit adds the pixel output currents to generate a predetermined pixel block. It is configured to include an adder circuit that forms a signal representing the output of the sum.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a distance measuring device according to a first embodiment of the present invention.

In FIG. 1, light emitted from an infrared light emitting diode (IRED) 11, which is a light projecting means, is applied to a subject 1 through a condenser lens 12. The reflected light from the subject 1 is received by the light receiving lenses 13a and 13b.
The light is incident on the sensor arrays 14a and 14b, which are sensors for receiving light. These sensor arrays 14a and 14b correspond to, for example, one pixel forming a sensor array for detecting an image signal. A pulse signal is transmitted from the remote control transmitter 2 of the subject 1 to remotely operate the distance measuring device.

The outputs of the sensor arrays 14a and 14b are passed through a switch section 15 to a stationary light removal circuit 16, an integration determination section 17 having an integration circuit, an A / D conversion section 18,
It is supplied to the adder circuit 19. The output from the A / D converter 18 is supplied to the CPU 20.

The CPU 20 is an arithmetic control unit composed of a one-chip microcomputer or the like. This CP
The U20 includes a driver 2 for driving the above-described integration determination unit 17, A / D conversion unit 18, and IRED 11 described above.
3, a strobe circuit 25 for driving the strobe light emitting section 24, a focusing section 26, and an E as a storage means.
The EPROM 27 and the release switch 28 are connected.

In the CPU 20, the arithmetic control unit 30
A switch unit 31, a compression circuit 32, a direct integration circuit 33, a pulse determination unit 34, and a correlation calculation unit 35.
And a reliability determination unit 36, a light amount determination unit 37, and a comparison constant circuit 38.

In the sensor arrays 14a and 14b, light-receiving element pixels are arranged side by side. Reflected light from the subject 1 is incident on the sensor arrays 14a and 14b via the light receiving lenses 13a and 13b. In order to form the image of the subject 1 on the sensor arrays 14a and 14b, two light receiving lenses 13 are provided in front of each sensor array.
a and 13b are provided separated by the focal length f. The parallax B is given to these lenses, and the subject distance L is obtained by the principle of triangulation.

Depending on the size of the subject distance L, the image of the subject 1 formed on the two sensor arrays 14a and 14b changes the relative position with respect to the optical axis of each lens. In order to detect this, the switch unit 15 outputs the output of each sensor to A / D.
The data is input to the CPU 2 via the conversion unit 18. A
In the / D converter 18, the integrated output from the sensor arrays 14a and 14b (here, the integrating circuit is included in the A / D converter 18 and omitted in FIG. 1) is converted into a digital signal. .

Then, the CPU 20 compares the digital image signals of these two sensor arrays 14a and 14b to detect the relative position difference and calculate the distance. In order to check whether the images detected by the two sensor arrays 14a and 14b are of the same subject, the CPU 20
It has a function such as a correlation calculator 35 for checking whether or not the image pattern is suitable for distance measurement and detecting the relative position difference of the image.

The switch section 31 is for switching the output from the first adder circuit 19a in the adder circuit 19 to the compression circuit 32 and the direct integration circuit 33.

The compression circuit 32 converts a current signal into a compression voltage by a diode, and is built in the CPU 20 monolithically. The reliability determination unit 36 determines the result of the pattern determination when the degree of coincidence of the images when the relative position difference is detected and the pattern determination result of the image, the low contrast, the repetitive pattern, the monotonous increase, and the monotonous decrease pattern. Therefore, the reliability of distance measurement is determined.

Further, the light quantity judging section 37 projects the distance measuring light when the stationary light is removed, and judges the quantity of reflected light which is reflected by the subject 1 and is incident. These determination results are supplied to the arithmetic and control unit 30. The method of determining the reflected light amount will be described later.

Further, the comparison constant circuit 38 preliminarily stores in the EEPROM 27 when the light quantity judging section 37 judges the light quantity.
It is a circuit for reading and setting the comparison constant stored in.

The control amount of the focusing section 26 is determined based on the result of each of these functions in the CPU 20.

Further, the CPU 30 uses the release switch 2
8 detects the input state and controls the camera photographing sequence. Furthermore, even during distance measurement, if necessary,
The IRED 11 is controlled to emit light via the driver 23, and the strobe light emitting section 242 is controlled to emit light via the strobe circuit 25.

In the present invention, the distance measuring sensor (sensor array) 14a arranged as shown in FIG.
The image signal output from the predetermined area has a low contrast as shown in FIG. 2B, a repetitive pattern as shown in FIG. 2C, or the image signal shown in FIG.
If the pattern is a monotone change pattern as shown in (d),
Furthermore, when the reliability of the result of the correlation calculation is low, IRE
D11 is projected and distance measurement is performed by the pattern of the reflected signal light. FIG. 2E shows an output pattern corresponding to the light projection pattern when the IRED 11 is projected.

A mask for pattern formation may be provided in front of the condenser lens 12, or the pattern of the light emitting portion itself may be used.

Further, when the signal light reflected by the IRED 11 is small, the strobe light emitting section 24 having a larger light quantity is emitted.
Distance measurement is performed by light projection using. However, in this case, since the reflected signal light does not have a specific pattern, in many cases, the signal light distribution has a low contrast as shown in FIG. However, if the subject exists only in the central portion of the screen, contrast occurs as shown in FIG. 2 (g), and the distance can be measured by this image.

The positional relationship between the sensor array and the light projection pattern is shown in FIG. 3 with reference to the screen of the camera to which the present invention is applied.

The monitor area 41 of the sensor array is displayed on the screen 4
It becomes the center of 0, and the strobe light must illuminate the entire screen to control the exposure, resulting in a wide pattern 42.
Then, the IRED pattern light forms an infrared light pattern as represented by the pattern 43.

In such a distance measuring device, a mode in which the distance is measured by the relative position difference of the image signals of the object without the projection of the distance measuring light is called passive AF. On the other hand, a distance measuring mode that involves the above-mentioned steady light removal operation and light projection such as IRED or strobe is called active AF.

Here, a method of extracting reflected signal light, which is a feature of active AF, will be described with reference to FIG.

In FIG. 4, the light emitted from the infrared light emitting diode (IRED) 11, which is the light projecting means, is applied to a subject (not shown) through the condenser lens 12. Then, the reflected light from the subject (not shown) is incident on the light receiving element 14a ₁ through the light receiving lens (not shown).
The light receiving element 14a ₁ corresponds to, for example, one pixel forming a sensor array for detecting an image signal.

Although the magnitude of the photocurrent I _P output from this is changed according to the amount of incident light, when the switch unit 15 is connected to the current detection circuit 16a, the photocurrent I _P is detected by the current detection circuit 16a. Circuit 16a, hold capacitor 1
It is supplied to the ground (GND) through a stationary light removal transistor 16b which forms a stationary light removal circuit together with 6c. On the other hand, the integrating amplifier 45a and the integrating capacitor 4
5b, the reset switch (SW) 45c, etc., the current detection circuit 1 so that no current flows in the integration circuit 45.
The gate voltage of the transistor 16b is controlled by 6a.

The holding capacitor 16c is for fixing the gate potential. In this state,
For example, when the IRED 11 is caused to emit light and the distance measuring light is pulsed to the subject through the condenser lens 12 and the current detection circuit 16a is deactivated, the above-mentioned capacitor is used for the rapid change of the pulsed light. Changes in voltage across 16c cannot respond. Therefore, when the switch 45d is turned on, only the photocurrent corresponding to the pulsed light is input to the integration circuit 45, and the photoelectric conversion voltage based on the distance measurement pulsed light is output to the output of the integration amplifier 45a. It This output is A
If the D / D conversion is performed, the reflected light amount data corresponding to only the reflected signal light component can be detected.

The direct integration circuit 33 has an integration amplifier 33a and a capacitor 33b.

The above is the description of the circuit for projecting the signal light from the camera and detecting the reflected signal light.

As described above, during distance measurement, the two distance measurement methods are selectively used, and focusing can be performed without an object that is difficult.

The photocurrent output from the light receiving element 14a ₂ is supplied to the integrating circuit 46 via the switch section 15.

Next, referring to the flow chart of FIG.
The operation of the distance measuring device according to the present embodiment will be described.

First, in step S1, distance measurement is performed in the passive mode described above. Next, in step S2, the integration time t _INT when the image signal is integrated to a predetermined level is obtained. Then, in step S3, the reliability of the passive AF is determined.

Here, in the above-mentioned pattern judgment, or
The reliability of passive AF is high due to the result of correlation calculation
In this case, the process proceeds to step S4 and the two image signal positions
The distance is calculated by triangulation. On the other hand, passi
If the reliability of AF is low, move to step S5.
Then, pre-distance measurement using the IRED11 is performed. this
When the pulsed light of a predetermined time is n₀Projected repeatedly, A / D conversion
Integrated voltage V _INTIs required.

If this integrated voltage V _INT is large, then I
Although it can be determined that the light from the RED 11 has reached the subject 1, if V _INT is small, it is considered that the light amount of the IRED 11 is insufficient, and stronger stroboscopic light projection is performed. However, at this time, a correct determination cannot be made unless the constant light components such as the sunlight illuminating the subject 1 and the artificial illumination are taken into consideration as described above.

Therefore, in order to detect the stationary light component, the integration time monitor signal t _INT (see step S2) at the time of the passive AF in step S1 is used to judge the brightness in step S6. Be seen. That is,
By comparison with the t _INT and the predetermined time t _0, the integral voltage V _{IN T} when in IRED pre integration in step S4
The determination voltages V ₁ and V ₂ for determining the magnitude of are determined.

If it is determined in step S6 that t _INT is short and bright, the process proceeds to step S11, and the determination voltages V ₂ and V _INT larger than V ₁ are compared. Further, in a dark scene, when the constant light is small and t _INT is long, constants V ₁ and V smaller than the determination voltage V ₂ are used.
_By comparing _INT, it is determined whether the distance measurement is performed by the IRED 11 or the strobe light emitting unit 24.

The integrated voltage V _INT may be selected as the integrated voltage of the largest incident light amount of all the sensors forming the sensor array, or the integrated voltage of the largest incident light amount of a predetermined area of the sensor array may be selected. The larger one may be selected.

The distance from the light source thus determined is measured in the active mode using the light of the IRED 11 or the strobe light emitting section 24 (main distance measurement) in step S8 or step S12. In this method, the light projection integration is repeated until a predetermined voltage is reached by light emission for a predetermined time.

That is, in the case of distance measurement by the IRED11, it is controlled by the loop of steps S8, S9 and S10. On the other hand, in the case of distance measurement by the strobe light emitting section 24,
It is controlled by the loop of steps S12, S13 and S14. In any case, when the light projection integration is performed a predetermined number of times or more, energy is wasted and the time lag is also affected. Therefore, in steps S10 and S14, an integration number limiter (N ₁ , N ₂ ) is provided.

In step S15, the result P (the integrated voltage V _INT divided by the number of integrations) obtained by integrating the reflected light amount in this way is obtained. Next, in step S16, pattern determination is performed. Then, the above step S
From the results obtained in 15 and S16, step S17
At, it is determined whether or not triangulation is possible.

If the reflected light image signal enables triangulation, the process proceeds to step S18 and triangulation is performed. Then, the reliability of the result of the triangulation is determined in step S19. As a result, if the reliability of the triangular distance measurement is high, the actual distance measurement ends.

On the other hand, if the reliability of triangulation is low, or if it is determined in step S17 that the pattern is not sufficient, the process proceeds to step S20 and the light amount AF based on the preceding reflected light amount P is detected. Is done. This is a distance measurement method that utilizes the fact that when light is projected and the amount of reflected light is examined, a large amount of light is returned from short-distance ones and a small amount of light is returned from long-distance ones. This is an effective distance measurement method even for subjects that do not exist. However, it is assumed that the reflectance of the subject is within a predetermined range.

As described above, in order to detect the image signal of the object, a sensor having a plurality of light receiving surfaces is used.
By utilizing this light receiving surface, not only the above-described distance measurement but also a sensor for exposure control, strobe control, or remote control reception necessary for a camera function can be configured.

That is, at the time of distance measurement, as shown in FIG. 6A, a change in the brightness of light (image signal) in a predetermined area on the screen is monitored by minute pixels. However, FIG.
As shown in (b), if the outputs of all the light receiving surfaces are added and used as if they were one large light receiving surface,
It is suitable as a light receiving range for remote control reception and average photometry.

Further, as shown in FIG. 6 (c), if the sensor outputs in a narrowed range are added, a light receiving surface having an appropriate size for spot photometry can be obtained.

The concept of integration control when obtaining an image signal has been described above with reference to FIG. 7, but during photometry, the outputs of a plurality of sensors are added as described above,
It is faster to handle them collectively and the processing can be simplified. Further, when it is used as a light receiving sensor for a remote controller, since a pulse signal from the remote controller transmitter 2 is discriminated using a bandpass filter, there is a problem through an integrating circuit.

Therefore, in the present embodiment, the outputs of the sensor arrays 14a and 14b are not input to the A / D conversion unit 18 including the integration circuit by the switch unit 15, and the addition circuit 1
I am able to input in 9.

The sensor arrays 14a and 14b respectively monitor the area shown in FIG. 6A, and when measuring the distance,
Since a pair of sensors are expected to have similar functions in order to perform triangulation using subtle parallax, it is possible to treat them as independent sensors for other purposes.

On the other hand, it is I to connect the remote control circuit and the photometry compression circuit to only one sensor array.
Since not only a wiring problem on C occurs but also noise is likely to be superimposed and the distance measurement accuracy is deteriorated due to complication, it is preferable to evenly allocate such measures to each sensor array.

Therefore, in the example of the configuration shown in FIG. 1, the output of the sensor array 14a is guided through the switch section 15 from the adder circuit 19a to the compression circuit 32 or the direct integration circuit 33. . Then, the output of the other sensor array 14b is input to the pulse determination unit 34 for the remote controller via the adder circuit 19b.

By properly using the pair of sensor arrays as described above, for example, the pattern of remote control reception is shown in FIG.
Fix each sensor function as shown in (b) and make the photometric pattern switchable to the size of spot photometry as shown in FIG. 6 (c). Can simplify the design. Considering an extreme example, the adder circuit of the sensor array 14a adds only the area shown in FIG. 6C, the adder circuit of the sensor array 14b always adds the area shown in FIG. 6B, and so on. It is also possible to fix the pattern.

By the way, each sensor array is shown in FIG.
If all patterns shown in (a), (b), and (c) can be taken, the logic circuit of the switch unit 15 becomes complicated. Therefore, in the present embodiment, as described above, the two sensor arrays of the distance measuring device are selectively used according to the situation to improve the degree of freedom in design.

The addition output of each pixel of the sensor array is obtained by, for example, switching the switch unit 15 shown in FIG.
It can be obtained by connecting the electrodes of a ₁ and 14a ₂ and controlling so as to lead to the compression diode (compression circuit) 32, and letting the photocurrent of the sensor flow into the common diode.

Further, the switching control of the switch unit 31 allows the direct integration circuit 33 to be guided to the compression circuit 32 instead of the compression circuit 32. Thus, before exposure, the compression circuit 32 enables photometry in a wide dynamic range, and after exposure, the direct integration circuit 33 determines the amount of light incident on the sensor array and adjusts strobe light emission. become.

Further, the added output of the other sensor array 14b is input to the pulse determination section 34, and when the photographer transmits a remote control signal (light modulated to a predetermined frequency) using the remote control transmitter 2, I am able to extract it. The CPU 20 performs camera control such as determining this signal and starting a release operation.

The sequence at the time of shooting by the camera equipped with the distance measuring device having such a configuration will be described below with reference to the flowchart of FIG.

First, in step S31, it is determined whether or not the photographer has operated a release button corresponding to the release switch 28. Here, when the release operation is performed, the shooting sequence from step S34 is started. On the other hand, if the release operation is not performed,
Control goes to step S32.

In step S32, the outputs of the sensor array 14b are added to receive the remote control signal.
Then, in the following step S33, it is determined whether or not the remote control transmitter 2 has been operated. As a result, if the remote control transmitter 2 is operated, the process proceeds to step S34, and if not, the process proceeds to step S31.

In step S34, the following step S35
At, the output of the sensor array 14a is processed to be added. Then, in step S35, photometry is performed using the addition signal of the sensor array 14a.

Next, in step S36, prior to the acquisition of the image signal for distance measurement in the following step S37, the integration determination section 17 and the A / D conversion section 18 are used instead of the addition circuit 19 side.
The switch section 15 is switched to the side so that each pixel output can be determined. Then, in step S37, distance measurement is performed.

In step S38, the taking lens is focused on the basis of the distance measurement result thus obtained. In step S39, prior to the start of exposure in subsequent step S40, the sensor 14a is made an addition output, and the output is guided to the direct integration circuit 33. This is because when strobe light emission is performed during exposure, it is determined that the reflected light has reached a predetermined level, and the light emission amount is controlled.

Thus, when the exposure is started in step S40 and the stroboscopic light emission is started in step S41,
In step S42, determination of direct integration is performed. Here, when the direct integration ends, this action controls the strobe light amount with proper exposure in step S43 to end the light emission, and in step S44 ends the exposure.

As described above, according to the first embodiment, an image signal is obtained by using a distance measuring sensor, an average distance measuring value is obtained by addition, and a wide range is obtained. It can contribute to downsizing and cost reduction of a camera by receiving a remote control signal from the device and judging its pulsed light to use as a multi-function sensor for cameras that can support various functions with a single sensor. it can.

Although various functions are incorporated, a switch function for adding only a predetermined pixel portion is provided, and the functions are organized by separately using each of the two sensor arrays as a remote controller and a photometric sensor. The configuration can be simplified, low noise countermeasures can be taken, and the reduction in distance measurement accuracy can be prevented.

Next, a second embodiment of the present invention will be described.

In the second embodiment, the above-mentioned first embodiment is used.
It is possible to provide a high-performance multi-function sensor corresponding to more various scenes than the embodiment.

FIG. 9 is a diagram showing the structure of the distance measuring apparatus according to the second embodiment of the present invention. Incidentally, the above-mentioned first
The same reference numerals are given to the parts different from the configuration of the embodiment and the description thereof will be omitted.

In the second embodiment, the light receiving sensor is not the sensor array but the area sensors 21a and 21b in which pixels are arranged in the x and y directions are used. Are mainly different.

That is, the output of the area sensor 21a is
The switch unit 15a switches between the stationary light removal circuit 16 and the integration determination unit 17a, and the addition circuit 51. Similarly, the output of the area sensor 21b is switched by the switch unit 15b to the stationary light removal circuit 16, the integration determination unit 17b, and the addition circuit 55.

Then, the integration decision units 17a and 17b are provided.
Output of A / A in the CPU 50 via the output circuit path 60.
It is supplied to the D conversion unit 18a.

The output of the adding circuit 51 is passed through the remote control signal discriminating circuit 52 and the lip flow detecting circuit 53, and then the CPU 5
It is supplied to the pulse determination unit 34 within 0. Further, the output of the adder circuit 55 is switched to the compression circuit 57 and the direct integration circuit 58 by the switch section 56. Then, the output of the compression circuit 57 is supplied to the A / D conversion unit 18b in the CPU 50. Further, the output of the direct integration circuit 58 and the output of the D / A converter 61 in the CPU 50 are supplied to the comparator 59 for comparison, and then the CPU 5
Supplied to zero.

In the switch sections 15a and 15b, the outputs of the area sensors 21a and 21b are determined by the integral judging section 1
In 7a and 17b, only a predetermined part is integrated pixel by pixel, or when the strobe light emitting section 24 or the IRED 11 emits light, only the stationary light is removed by the stationary light removing circuit 16 so that only the signal light is taken out. , Several pixels are collectively treated as one pixel to support various functions of the camera.

The output of the adding circuit 51 is led to the remote control signal discriminating circuit 52 and the ripple detecting circuit 53. The remote control signal discriminating circuit 52 is the same as that described above, but the ripple detecting circuit 53 extracts a ripple component of light peculiar to an artificial light source such as a fluorescent lamp, and is configured by a general differentiating circuit. .

When it is determined that the artificial light source illuminates the subject by the ripple detection, there is known a technique for preventing the coloring peculiar to the light source from being generated on the image to emit strobe light. Has been.

Further, the output of the adder circuit 55 is input to the direct integration circuit 58 or the compression circuit 57 by switching the switch unit 56, as in the first embodiment described above.

A D / A converter 61 is built in the CPU 50, and its output changes depending on the sensitivity of the film and the brightness of the taking lens. The output of the D / A converter 61 and the output of the direct integration circuit 58 are compared by the comparator 59. As a result, the strobe light emission stop control is performed during the exposure control involving the strobe light emission.

As described above, the CPU 50 also has an A / D converter built therein. A / D converter 18a
Reads the compressed output and performs photometry for exposure control. On the other hand, the A / D converter 18b is for obtaining a digital image signal from each pixel output for distance measurement.

In such a configuration, for example, if the switch sections 15a and 15b guide only the outputs of the sensors in one row of the area sensors 21a and 21b to the integral judging sections 17a and 17b, FIGS. As shown in, the same area as that of the first embodiment can be used as a distance measuring area.

If the area for distance measurement is increased, it is necessary to increase the stationary light removal and the integration circuit (see FIG. 4) as described above, and the circuit scale increases. Therefore, it is preferable to limit the area as much as possible. In other words, the feature of the second embodiment is that while the area sensors 21a and 21b having a large number of pixels are used, the integration determination units 17a and 17b limit the number and the switch unit 15a during distance measurement, The area is limited by 15b and input to the integration determination unit.

In the case of photometry, remote control, and ripple detection, the outputs of all the sensors are monitored as shown in FIGS. 11 (a) and 11 (b), but in this case, the integration determination sections 17a, 17b are used. A circuit necessary for each pixel such as the stationary light removing circuit 16 and the stationary light removing circuit 16 is not used, and each processing circuit (remote control, ripple) is configured by the addition circuits 51 and 55 so that all the pixels function as if they were one light receiving surface. , Direct integration,
Since it is input to (compression), simplification of control and circuit can be achieved.

At the time of photometry, center-weighted photometry may be performed as shown in FIGS. 12 (a) and 12 (b). Also in this case, only this limited area (central portion) is added and collectively input to a single processing circuit.

Further, as shown in FIGS. 13A and 13B, when an array in the vertical direction of the screen is selected, an image in the vertical direction is detected, and this is repeated to detect an image change. Therefore, it can also be used as a sensor for determining image blur and camera shake.

Further, since the stationary light removing circuit is large-scale as shown in FIG. 4, it is necessary to limit the number of circuits. For example, if a circuit of several tens of order can be prepared, FIG. As shown in (), by inputting the output of the sensor, which is discretely distributed at each point of the area sensor, to this stationary light removal circuit, the distribution of the reflection signal at the time of strobe irradiation can be roughly determined.

As shown in FIG. 14B, when a person stands in the screen, the reflected signal light from that person becomes strong,
By determining this and focusing and measuring the distance only to that portion, the main subject can be narrowed down, the focus can be adjusted, and the exposure can be controlled at high speed.

Such control also applies to the switch parts 15a, 1
5b makes it possible by selecting the pixel of the area sensor so that it can be led to the circuit of the next stage.

FIG. 15 shows that such a switch unit
7 is a flowchart illustrating an operation example of narrowing down a main part of a screen easily and at high speed.

That is, in step S51, as shown in FIG.
As shown in (a), discretely distributed pixels are selected (this pixel selection is performed by the data of the EEPROM 27) and are guided to the circuit with the stationary light removal function. Next, in step S52, when the strobe light is emitted, as shown in FIG. 14B, the light is reflected from the portion where the main subject is present and the light is not reflected from the portion where the subject is not present. .

Since the main subject position can be obtained by examining the distribution obtained in step S52, the pixel signal of only that portion is taken out by the switch portion in step S53. Next, in steps S54 and S55, if distance measurement and photometry are performed, the number of pixels that are smaller than the wide area sensor is limited, and correct focus and exposure control can be performed at high speed.

Next, in step S56, the camera shake determination area is limited. Then, in step S57,
The image signal of the portion is repeatedly detected and the change is determined. Here, if it is determined that there is a change, the process proceeds to step S58 and a camera shake warning or the like is performed.

By doing so, the user can shoot while paying attention to camera shake.

As described above, according to the second embodiment, no matter which position on the screen the main subject is, the position is determined at high speed and the distance is measured only in a limited area. It is possible to perform photometry, focus effectively, and control exposure.

According to the above embodiment of the present invention,
The following configuration can be obtained. That is, (Supplementary Note 1) In a light receiving sensor for a camera having a pair of light receiving sensor rows for detecting a light distribution from a subject through a pair of light receiving lenses, the output current of each pixel forming the sensor row is There is a switch means for leading to the first or second circuit, the first circuit is an integrating circuit for forming an image signal from the pixel output, and the second circuit adds the pixel output current. And a light receiving sensor for a camera, wherein the light receiving sensor is an adder circuit that forms a signal representing the total output of a predetermined pixel block.

(Additional Item 2) The second circuit is a remote control circuit for passing and amplifying a pulsed optical signal of a predetermined frequency, a compression circuit for flowing the added current into a diode, or a capacitor having a predetermined capacity for the added current. The light receiving sensor for a camera as set forth in appendix 1, wherein the light receiving sensor is connected to a second integrating circuit which is fed into

(Additional Item 3) Of the pair of light receiving sensor arrays, one sensor array is connected to the bandpass filter through the second circuit, and the other sensor is connected through the second circuit. 2. The light receiving sensor for a camera according to claim 1, wherein the light receiving sensor is connected to a diode compression circuit.

[0102]

As described above, according to the present invention, the number of processing circuits is limited while using a sensor array or area sensor capable of monitoring a wide range, and the configuration is simplified, so that there is no problematic scene. Distance and photometry can be performed with simple control.

Further, since it can be easily applied to a remote control light receiving element, a photometric element, a camera shake detecting sensor, etc., it is possible to reduce the size and cost of the entire camera.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a distance measuring device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a distance measuring sensor and an image signal output from the distance measuring sensor.

FIG. 3 is a diagram showing a positional relationship between a sensor array and a light projection pattern when a screen of a camera to which the present invention is applied is used as a reference.

FIG. 4 is a diagram illustrating a method of extracting reflected signal light of active AF.

FIG. 5 is a flowchart illustrating an operation of the distance measuring device according to the first embodiment of the present invention.

FIG. 6 is a diagram showing an example of an area to be monitored on the screen.

FIG. 7 is a timing chart for explaining the operation for determining the light / darkness of stationary light.

FIG. 8 is a flowchart illustrating an operation of the camera equipped with the distance measuring device according to the first embodiment during shooting.

FIG. 9 is a diagram showing a configuration of a distance measuring device according to a second embodiment of the present invention.

FIG. 10 is a diagram showing an example of a monitor area for distance measurement of an area sensor.

FIG. 11 is a diagram showing an example of a monitor area of an area sensor for photometry, remote control, and ripple detection.

FIG. 12 is a diagram showing an example of a monitor area of the area sensor during center-weighted photometry.

FIG. 13 is a diagram showing an example of a monitor area of an area sensor in which the vertical direction of the screen is selected.

FIG. 14 is a diagram showing an example of a monitor area of an area sensor when a stationary light removing circuit is used.

FIG. 15 is a flowchart illustrating an operation example of a main subject monitor.

[Explanation of symbols]

1 subject, 2 remote control transmitter, 11 Infrared light emitting diode (IRED), 12 condenser lens, 13a, 13b light receiving lens, 14a, 14b sensor array, 15, 31 switch part, 16 Stationary light removal circuit, 17 Integral decision unit, 18 A / D converter, 19 adder circuit, 20 CPU, 23 drivers, 24 Strobe emission part, 25 strobe circuits, 26 Focusing section, 27 EEPROM, 28 Release switch, 30 arithmetic control unit, 32 compression circuit, 33 Direct integration circuit, 34 pulse determination unit, 35 Correlation calculator 36 Reliability determination unit, 37 Light intensity determination unit, 38 Comparison constant circuit.

Claims (4)

[Claims] 1. A light receiving sensor for a camera, comprising a pair of light receiving sensor rows for detecting a light distribution from a subject through a pair of light receiving lenses, wherein each pixel output current constituting the sensor row is first Alternatively, a switch means for leading to a second circuit is provided, the first circuit includes an integrating circuit for forming an image signal from the pixel output, and the second circuit adds the pixel output current. And a light receiving sensor for a camera, which includes an adder circuit for forming a signal representing an output of a sum of predetermined pixel blocks. 2. The second circuit comprises a remote control circuit for passing and amplifying a pulsed optical signal of a predetermined frequency, a compression circuit for flowing the addition current into a diode, or a flow circuit for supplying the addition current into a capacitor having a predetermined capacity. 2. The light receiving sensor for a camera according to claim 1, wherein the light receiving sensor is connected to the integrating circuit of 2. 3. One of the pair of light-receiving sensor rows is connected to a bandpass filter via the second circuit, and the other sensor is diode-compressed via the second circuit. The light receiving sensor for a camera according to claim 1, wherein the light receiving sensor is connected to a circuit. 4. The output of the light receiving sensor array corresponding to one of the pair of lenses is guided to the remote control circuit, and the output of the light receiving sensor array corresponding to the other lens is guided to the diode or the second integrating circuit. The light receiving sensor for a camera according to claim 2, wherein the light receiving sensor is used.