JP2000047092A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera by which high-accurate range-finding result can be obtained by obtaining an adequate optical image signal, and also by which the misidentification of light emitting timing in the case of exposure operation by a photographer, etc., can be prevented so that photographing failure can be prevented. SOLUTION: This camera has an integration means 4a integrating an optical signal in accordance with the image patterns 3a and 3b of an object 6, and a range finder performing range-finding to the object by an integration signal obtained by the means 4a; is provided with an integration deciding means 4b deciding integration amount obtained by the means 4a, stroboscopic light emitting means 23 and 24 performing auxiliary and intermittent light emission, and an integration control means 10 controlling the integration operation of the integration means and the light emission operation of the means 23 and 24 based on the decision of the means 4b; and the means 10 controls the camera to operate in either one of the operating modes of a first light emission mode in which the light emission operation of the means 23 and 24 is performed in synchronism with the integration operation of the means 4a and a second light emission mode in which the light emission operation of the means 23 and 24 is not performed in synchronism with the integration operation of the means 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly to a camera provided with a distance measuring device capable of measuring a distance to a subject with high precision and performing a focusing operation reliably.

[0002]

2. Description of the Related Art Conventionally, as a distance measuring apparatus used for a camera for taking a photograph or the like, a method using light has been widely used. For example, it is roughly classified into an "active type" in which a signal beam is projected from the distance measuring device side and a "passive type" in which a luminance distribution image of a target (subject) is used. Both of these distance measurement methods use the principle of triangulation as a basic operation principle. In the active type, the distance between the light-emitting unit and the light-receiving unit is a basic length,
In other words, this is a method of performing triangulation with the base line length. On the other hand, in the passive type, the distance to the object is calculated based on the difference in the relative position of the image of the object due to the parallax of the two light receiving units, based on the position interval between the two light receiving units. I have. In the passive type, since it is necessary to measure the amount of light at each light receiving position in order to observe the image of the object, a line sensor or the like in which a plurality of optical sensors are arranged is usually used. is there.

Here, a configuration of a general passive type distance measuring apparatus and a distance measuring method using the same will be described with reference to FIG.

FIG. 27 is a block diagram schematically showing the configuration of a conventional passive type distance measuring apparatus. As shown in FIG. 27, the conventional passive type distance measuring device has two light receiving lenses 101a and 101a arranged apart from each other by a base line length B.
101b, and sensor arrays 102a and 102b, which are line sensors provided behind the light receiving lenses 101a and 101b and receive light beams from the subject 106 which are transmitted through the light receiving lenses 101a and 101b and are respectively incident thereon.
An A / D converter 104 that converts a subject light signal (analog signal) obtained and photoelectrically converted by the sensor arrays 102a and 102b into a digital signal;
The arithmetic unit 105 is configured to receive the optical signal converted by the D conversion unit 104 and perform a predetermined operation, and the CPU 110 and the like as control means for controlling the entire distance measuring device.

[0005] On the sensor arrays 102a and 102b,
Light patterns as shown by the curved patterns 103a and 103b are formed. These light patterns 103a and 103b
Is the luminance distribution of the object 106 and the two light receiving lenses 10
It is formed depending on the relative positional relationship with 1a and 101b.

The light patterns 103a and 10 obtained here
The relative position difference x of 3b is the base length B, the light receiving lens 101a
It depends on the distance f between 101b and the sensor arrays 102a and 102b, and the distance L to the subject. That is, the following relationship is established.

X = (B × f) / L (1) ● Means by such a structure, that is, the sensor array 102a
The technical means that receives the output of 102b and calculates by the calculation unit 105 to calculate the relative position difference between the light patterns 103a and 103b is what is called a correlation calculation. Various proposals have been made for this correlation operation, for example, in Japanese Patent Publication No. 7-54371.

Incidentally, a sensor used in a passive type distance measuring device may cause a problem that it is impossible to reliably obtain a light image signal from a subject in a dark shooting environment. In some cases, it may be impossible to measure the distance.

Therefore, in order to solve such a problem, when taking a photograph in a dark environment, the auxiliary light projection means is used during a distance measuring operation performed prior to a photographing operation (exposure operation). For example, Japanese Patent Application Laid-Open No. Hei 4 (1998) proposes a technical means for reliably performing a distance measurement operation by irradiating a subject with light emission (auxiliary light) from the strobe device.
No. 329,769 and Japanese Patent Application Laid-Open No. 5-34577.

In the case where a strobe device is used as such means, that is, a means for projecting auxiliary light when performing a distance measuring operation by the distance measuring device, a large amount of light can be obtained by the strobe device. Since an optical image signal can be reliably obtained, there is an advantage that a more accurate distance measurement result can be obtained.

Further, various proposals have been made by, for example, Japanese Patent Application Laid-Open No. 4-242273 for using a strobe device as a means for projecting auxiliary light during a photographing operation, and for controlling the amount of light emitted by the strobe device. ing. The means disclosed in Japanese Patent Application Laid-Open No. Hei 4-2422731 relates to control of the amount of light emission at the time of strobe light emission executed to suppress the so-called red-eye phenomenon, and to strobe light executed to reduce the red-eye effect. In order to prevent the photographer or the subject to be misunderstood between the light emission operation, that is, the so-called pre-emission operation and the strobe emission operation during the exposure operation, the pre-emission is continuously emitted at short intervals. It is to control.

[0012]

However, similarly to the above-described flash light irradiation used for reducing the red-eye effect, a photographer or a person to be a subject can use an auxiliary light, which is performed prior to a distance measuring operation. There is a risk that the light emitting operation may be mistaken for being a strobe light emitting operation for an exposure operation.

If there is such a misunderstanding, for example, the photographer may move the camera after performing the pre-emission and before performing the exposure operation, or the subject or the like may move. . As a result, a so-called camera shake or subject blur occurs in the obtained photograph, and a failed photograph is created.

Control of the light emission operation of the strobe device is as follows.
In the normal case, the current is controlled on the order of amperes, so that the control is rough. Therefore, there is a problem that it is very difficult to perform fine light emission control.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a camera having a distance measuring device using a strobe device as means for emitting auxiliary light. By obtaining an appropriate optical image signal, a more accurate distance measurement result can be obtained, and the light emission operation of the auxiliary light during the distance measurement operation and the light emission operation during the exposure operation can be clearly distinguished. It is an object of the present invention to provide a camera which realizes the above-described light emission control of a strobe device, and can prevent a photographing mistake or the like without a photographer or a person who is a subject misunderstanding the light emission timing at the time of an exposure operation.

[0016]

In order to achieve the above object, a camera according to a first aspect of the present invention includes a camera having an auto-focusing device for focusing a subject on the basis of a subject image and a strobe light emitting device for performing auxiliary light emission. A first determining unit that determines whether or not the flash unit is required to emit light during photographing; a second determining unit that determines whether or not the flash unit is required to emit light during distance measurement; When at least one of the determination unit and the second determination unit determines that the flash unit needs to emit light, a light emission control unit that controls the flash unit to perform a light emission operation during a shooting operation and a distance measurement operation; It is characterized by having.

A camera according to a second aspect of the present invention has an integrating means for integrating an optical signal corresponding to an image pattern of a subject, and a distance measuring device for measuring a distance to the subject by using the integrated signal obtained by the integrating means. In the camera having the above, an integration determining means for determining the amount of integration obtained by the integrating means, a strobe light emitting means for performing auxiliary intermittent light emission, and an integration of the integrating means based on the determination by the integration determining means. An integration control means for controlling an operation and a light emission operation of the strobe light emission means, wherein the integration control means performs the light emission operation of the strobe light emission means in synchronization with the integration operation of the integration means before photographing. One of a first light emission mode and a second light emission mode in which the light emission operation of the strobe light emission means and the integration operation of the integration means are performed without synchronization. And controls to operate at de.

According to a third aspect of the present invention, in the camera according to the second aspect, the integration control means sets a shorter light emission time than the first light emission mode when controlling the second light emission mode. .

According to a fourth aspect of the present invention, there is provided a camera, comprising: integrating means for integrating an optical signal corresponding to an image pattern of a subject; and a first distance measuring apparatus for measuring a distance to the subject based on the integrated signal obtained by the integrating means. And a second projecting device for projecting a light beam for distance measurement to the object and a second distance measuring device for measuring the distance to the object by a signal based on signal light reflected from the object. An integration determining means for determining the amount of integration obtained by the means; a strobe light emitting means for performing auxiliary intermittent light emission; and an integrating operation of the integrating means and the strobe light emitting means based on the determination by the integration determining means. Based on the integration control means for controlling the light emitting operation and the distance measurement result by the second distance measurement device,
A first light emission mode in which the light emission operation of the strobe light emitting means is synchronized with the integration operation of the integration means, and a second light emission mode in which the light emission operation of the strobe light emission means and the integration operation of the integration means are not synchronized. And a mode switching means for setting any one of the following.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram showing the configuration of the camera according to the first embodiment of the present invention. In this figure, in order to avoid complication of the drawing, only members related to the present invention are shown, and other components are omitted.

As shown in FIG. 1, the camera according to the present embodiment has a so-called passive type distance measuring device. That is, the present camera is provided with two light receiving lenses 1a and 1b arranged at a distance of the base line length B, and at a focal distance f behind the light receiving lenses 1a and 1b, and transmitting through the light receiving lenses 1a and 1b. Arrays 2a and 2b, each of which receives a light beam from a subject 6 incident thereon through a line sensor, and converts the subject light signals (analog signals) obtained and photoelectrically converted by the sensor arrays 2a and 2b into digital signals. A to convert
An A / D converter 4, an arithmetic unit 5 that receives the optical signal converted by the A / D converter 4 and performs a predetermined operation such as calculating an image shift amount, and an entire distance measuring apparatus of the present camera. C, which is an arithmetic control means including a one-chip microcomputer for controlling
A flash light emitting device (hereinafter, referred to as a strobe device) 24 including a PU 10 and a flash light emitting portion such as a xenon tube, and a strobe light control unit including a strobe light emission control circuit for controlling a light emitting operation of the strobe device 24. Part 23
And a photometric unit 25 that measures the luminance of the subject light; a focus lens group 22 that forms a part of the photographing lens group and that can move in the optical axis direction for a focusing operation; Is a focus control unit that controls the movement of the focus lens group 22 on the basis of a focus control unit 21 including an actuator, an encoder, and the like, and a release switch (SW) that generates a release signal for starting execution of a shooting operation. ) 20 and the like.

The A / D converter 4 includes an integrating means 4a for integrating the optical image signal, and a judging part 4b which is an integral judging means for judging whether or not the strobe light emission operation is necessary at the time of the distance measuring operation. have. The strobe device 24 and the strobe control unit 23 form a strobe light emitting unit. Note that the distance between the two light receiving lenses 1a and 1b and the subject 6 is indicated by a symbol L.

A method of calculating the relative position difference between the light patterns of the distance measuring device in the camera according to the present embodiment having the above-described configuration will be described below. Sensor arrays 2a and 2
On b, light patterns as shown by the curved patterns 3a and 3b are formed. The light patterns 3a and 3b depend on the luminance distribution of the subject 6 and the relative positional relationship between the two light receiving lenses 1a and 1b.

That is, the positional difference between the two light receiving lenses 1a and 1b, that is, the relative positional difference x of the distribution of the light patterns 3a and 3b incident on the sensor arrays 2a and 2b due to the base line length B is the distance to the subject. (Hereinafter referred to as subject distance)
It changes depending on L. In this case, if the focal length f of the two light receiving lenses 1a and 1b is the subject distance L
Is obtained by L = B × f / x (2) ● (see also the above-mentioned equation (1)).

Each of the sensors of the sensor arrays 2a and 2b outputs a current signal according to the amount of incident light.
If the signal is converted into a digital signal by the / D converter 4, the image shift amount, that is, the relative position difference x can be calculated by the correlation operation by the operation unit 5. In response to this result, the CPU 10
Performs an operation based on the above equation (2). Thereby, the subject distance L is obtained. The above is the basic principle of the triangular distance measuring method in the passive type distance measuring device, and the general device configuration.

In general, the image shift amount calculating function is as follows.
It consists of two processes as described below,
These may be built in the CPU 10 as a control program. When the focus adjustment operation of the camera is performed using such a technique, the CPU 10 controls the operation of the camera, and controls the focus control unit 21 such as the focus adjustment focus lens 22 constituting a part of the photographing lens. By appropriately controlling the driving force of an actuator (not shown) such as a driving motor via the motor, a camera with a so-called automatic focus adjustment (autofocus; AF) function can be provided.

In order to calculate the amount of image shift, an operation step for checking how much the image is shifted in units of sensor pitch in the two sensor arrays 2a and 2b, that is, a correlation operation is required. Then, an operation step for calculating a more accurate deviation amount with a finer resolution, that is, an interpolation operation is required.

Here, a schematic procedure of each process relating to the correlation calculation and the interpolation calculation will be described below. First,
The correlation calculation process will be described.

When light having the pattern indicated by reference numeral 3a in FIG. 1 is incident on the sensor array 2a, the magnitudes of the outputs of the sensors R1 to R6 have a distribution as shown in FIG. This distribution corresponds to the waveform of the light pattern 3a. The symbol [R] shown in FIG. 3 indicates the right one of the two sensor arrays 2a and 2b,
Similarly, the symbol [L] shown in the following description indicates the left sensor array. Subscripts [1] to [6] added to [R] and [L] respectively indicate the light receiving lens 1
It indicates the absolute position of each sensor with reference to the optical axis of a · 1b. In this case, the left sensors L1 to L6
As a result, if an output signal substantially equal to that of the right sensors R1 to R6 is output, the relative position difference x between the two becomes zero. Therefore, the required subject distance L is “infinity”.

When the object 6 is at a "finite distance", that is, when the object 6 is not at infinity, both sensor arrays 2a
As shown in FIG. 4, the left sensor L at a position shifted (shifted) by the number of sensors determined by the relative position difference x of the image incident on the 2b and the pitch SP between the individual sensors is as shown in FIG. Thus, an output signal having a value similar to the above-described sensor outputs R1 to R6 (see FIG. 3) is obtained.

The value on the vertical axis in FIG. 2, that is, the sum FF (i) of the difference between the right sensor (R) and the left sensor (L) is obtained by the following equation. FF (i) = Σ | R (i) −L (i) | (3) ● That is, an arbitrary sensor output of the right sensor R and a corresponding sensor output of the left sensor L are subtracted, and The result of adding the absolute value for each sensor is FF. here,
First, Li is subtracted from Ri, the absolute value is obtained, i is changed within a predetermined width, and these are added.

Next, if one of the sensors Ri or Li is shifted by one unit and the same calculation is performed to obtain the difference, FF (i + 1) can be expressed by the following equation (4). FF (i + 1) = Σ | R (i + 1) −L (i) | (4) ● In this manner, the FF can be obtained by sequentially changing the shift amount. Then, the sum FF of the difference between the sensor R and the sensor L
Is considered to be the position where the correspondence is best established, and the shift amount (shift amount) in this case is obtained as the sign S to be shifted in FIG. 4 described above. The above is the schematic procedure of the process regarding the correlation operation.

FIG. 4 shows the output distribution of the two sensor arrays 2a and 2b, taking into account the value indicated by the symbol S.
Similarly to the above, equivalent outputs are obtained from the R-side sensors corresponding to the output distributions of the L-side sensors shifted by the shift amount S.

Next, the process of the interpolation calculation will be described with reference to FIGS. Actual two sensor arrays 2a
The amount of image shift on 2b is not exactly shifted by the pitch SP of each sensor, and in order to realize an accurate distance measurement operation, the amount of image shift is detected with finer accuracy than the sensor pitch SP. There must be. Therefore, an interpolation operation is performed.

In FIGS. 3 and 4, the symbols [R] and [L] indicate the sensor arrays 2a and 2b shown in FIG.
Represents a part of the sensor output of each of the sensors constituting the above. FIG. 5 is a graph in which the output of each sensor after the correlation calculation process has been shifted by the shift amount S and then is easily compared. That is, in FIG. 5, symbols L0 to L4 are to be accurately described as L (S) to L (S + 4). However, in order to avoid complication, symbols (S) are used. It is omitted and shown.

Here, even after being shifted by the shift amount S, light shifted by a relative positional difference x (see FIG. 1) with respect to the R-side sensor enters the L-side sensor. Shall be In this case, for example, the light incident on R0 and R1 is mixed and incident on the sensor L1, and the position difference x based on the sensor R is similarly applied to each sensor on the L side.
Are shifted sequentially. Therefore, it is understood that the sensor outputs (L1 to L3) on the L side are expressed as shown in the following equations. L1 = (1−x) · R1 + xR0 (5) L2 = (1−x) · R2 + xR1 (6) L3 = (1−x) · R3 + xR2 (7) ● Fmin. And this Fmin. When the values F-1 and F + 1 of the FFs whose shift amounts are shifted in the plus direction and the minus direction are expressed by using the outputs of the sensors Rn and Ln, the following expressions can be obtained. Fmin = Σ | Rn−Ln | (8) F−1 = Σ | R (n−1) −Ln | (9) F + 1 = Σ | R (n + 1) −Ln | (10) ● Using the equations (5) to (7), the equation (8)
-Expression (10), each value Fmin. , F-1,
F + 1 can be expressed as in [Equation 11] shown in FIG. Furthermore, the portion underlined in [Equation 11] of FIG. 25, that is, ｛| R0−R1 | + | R1−R2 | + | R2−R3 |｝, is expressed as (ΣΔR). The above-mentioned shift amount (position difference) x can be obtained by calculation using [Equation 12] shown in FIG. 26 without depending on (ΣΔR). The above is the process of the interpolation calculation.

Note that these calculations are performed in the calculation unit 5 in FIG. 1, but the present invention is not limited to this.
For example, inside the CPU 10 which is an arithmetic control unit,
You may comprise so that it may perform according to a predetermined program. In this case, the process shown in the flowchart shown in FIG. 6 is performed.

That is, the CPU 10 receives the outputs of the sensors of the sensor arrays 2a and 2b in step S1 (data reading processing), and in steps S2 and S3, executes the above-described correlation calculation (step S1) according to a predetermined program (software). S2) and interpolation calculation (step S
3) is executed, and based on the result, step S
In step 4, the extension amount of the focus lens 22 and the like of the photographing lens is calculated. After that, control for focus adjustment is performed by the focus control unit 21 and the like.

In the distance measuring apparatus which performs the basic operation as described above, if the brightness of the subject is insufficient, a clear light image signal cannot be obtained, and the accuracy of the distance measurement deteriorates ( Problem of passive type distance measuring device).

Therefore, in the range finder of the camera according to the present embodiment, the strobe device 24 (see FIG. 1) for irradiating the auxiliary light mainly at the time of the photographing operation toward the subject is changed to the auxiliary light at the time of the range finder operation. Is also used as a means for irradiating. That is, prior to the distance measurement operation, a flash light emission operation is performed by the strobe device 24 to project auxiliary strobe light to the object 6, thereby ensuring the brightness of the object in a desired distance measurement range. A light image signal from a necessary subject is acquired to improve the distance measurement accuracy. Specifically, the CPU 10 gives a light emission (trigger) signal to the xenon tube of the strobe device 24 via the strobe control unit 23, controls the light emission current of the xenon tube, and the like. The CPU 10 also controls the focusing control unit 21 based on the distance measurement result obtained as described above.
, The focus lens 22 and the like are controlled. This realizes a so-called autofocus operation in which a focus adjustment operation is automatically performed.

In general, the output of the sensor array is obtained by integrating a photocurrent into an optical image signal. The integrated waveform is shown in FIG.
Examples are shown in (a) to (e). In FIG. 7, the horizontal axis indicates the elapsed time, and the vertical axis indicates the integrated level (amount) of the optical image signal.

In the case where the subject is bright, as indicated by the symbol A in FIG. 7A, the photocurrent increases, so that the optical image signal reaches a reference value of an appropriate level (hereinafter referred to as an appropriate level). Tends to be shorter. On the other hand, when the subject is dark, the photocurrent becomes small as indicated by reference numeral B in FIG.
The integration time (t2) until reaching the appropriate level tends to be long. In the camera of the present embodiment, utilizing such characteristics, the A / D converter 4 converts the integration time required to reach an appropriate level into a digital value, and converts the A / D value of the optical image signal into a digital value. I'm trying to get.

That is, the A / D converter 4 determines a predetermined integration time from the brightest pixel within a predetermined photometric range based on the photometric value obtained by the photometric unit 25,
A predetermined A / D value is obtained by performing A / D conversion processing on the integration amount integrated by the integration means 4a of the / D conversion unit 4 within a predetermined integration time. In this case, as the difference between the integration amounts of the sensors is larger, the optical image signal becomes clearer, so that the ranging accuracy is improved.

However, the dynamic range of the integration circuit is limited by the power supply voltage and the circuit type, and therefore, a technique is required to limit the integration amount to an appropriate value within the range. In addition, in the case where the subject is dark, if the user waits to reach the appropriate level, the distance measurement time becomes longer, so that a desired shooting timing may be missed.

In consideration of this, in the present embodiment, as described above, the strobe device 2 is used prior to the distance measuring operation.
4 emits light to project auxiliary light to the subject 6 (see FIG. 7B). Thereby, the subject 6
Is increased to reduce the integration time (t3) when the environment around the subject 6 is dark (see FIG. 7C; t2> t3).

On the other hand, during integration of the optical image signal, the strobe device 2
7 is too long, the irradiation time (t4) of the auxiliary light by
(D) As shown in FIG. 7 (e), the light image signal to be integrated exceeds an appropriate level within a predetermined integration time, so that an accurate distance measuring operation cannot be performed. Therefore, in this case, a proper level is secured for the integral amount, and light emission control is performed so as to shorten the integral time, and control is performed such that the integral amount of the proper level is obtained by repeating this several times. .

The outline of the flow of the photographing operation of the camera having the above-described configuration according to the present embodiment will be described below with reference to the flowchart shown in FIG. When the main power of this camera is on and in the shooting standby state,
When the release switch 20 is pressed by the photographer and a release signal is generated, the CPU 10 receives the signal and controls the distance measuring device to execute a distance measuring operation in step S5. Subsequently, in step S6, the CPU 10 controls the photometric unit 25 to perform a photometric operation, and then proceeds to the next step S7.

In step S7, the CPU 10 controls the focus lens 22 via the focus control unit 21 based on the distance measurement result in step S5, and performs a focusing operation for moving the focus lens 22 to the focus position. Execute (lens control processing). Next, in step S8, the CPU 10
Is based on the photometry result in step S6 described above.
An exposure operation is performed by controlling a shutter mechanism and the like (not shown) (shutter control processing).

Then, in step S9, a film winding operation (winding process) for feeding the next photographing frame to the photographing position is performed, and a series of processes is completed to be in a photographing standby state (return).

In this case, a flash light emission operation by the strobe device 24 is performed when performing the distance measurement operation in step S5 (distance measurement processing) and when performing the exposure operation in step S8 (shutter control processing). May be When the light emitting operation is performed, for example, when the subject is in a bright environment, the light emitting operation is performed only once during the exposure operation or the distance measuring operation, or the light emitting operation is performed once. There are various cases, such as when not performed. In this way, when taking a picture, it is very confusing if the number of times of light emission operation is different depending on the surrounding environment etc. Also.

Therefore, in the camera according to the present embodiment, as shown in FIG. 9, when the light emission operation is required during either the exposure operation or the distance measurement operation, the camera performs the distance measurement operation and the exposure operation at the same time. By controlling the light emission operation at each of the two points, the above-described confusion is eliminated and the usability of the camera is improved.

FIG. 9 is a flowchart showing the details of the flow of the operation at the time of the photographing operation in the camera of this embodiment. When the release switch SW20 is pressed by the photographer and a release signal is generated while the main power supply of the camera is on and in a photographing standby state, the CPU 1 receives the release signal.
In step S11, the CPU 10 controls the photometric unit 25 to perform a photometric operation, and then in step S12, based on the photometric result, the CPU 10 determines whether or not strobe light emission is necessary during the exposure operation. Make a decision. In this case, the CPU 10 functions as a first determination unit. If it is determined that the strobe light emission operation during the exposure operation is necessary, step S
Proceeding to the process at 18, if it is determined that it is not necessary, the process proceeds to the next step S13.

In step S13, the CPU 10
In response to the signal from the determination unit 4b of the A / D conversion unit 4, it is determined whether or not a strobe light emission operation is necessary at the time of the distance measurement operation. Note that the CPU 10 in this case functions as a second determination unit. Here, when it is determined that the strobe light emission operation at the time of the exposure operation is necessary,
The process proceeds to step S16, and if it is determined that it is not necessary, the process proceeds to the next step S14.

In this case, when the light image signal of the subject light which has passed through the light receiving lenses 1a and 1b and entered the sensor arrays 2a and 2b is integrated by the integrating means 4a, the determination section 4b determines the light current. When the state shown by the symbol B in FIG. 7A is reached, it is determined that the strobe light emission operation during the exposure operation is necessary.

In step S14, the CPU 10
The distance measuring device is controlled to execute the actual distance measuring operation.
The distance measuring operation performed here does not involve a flash emission operation by the flash device 24. Subsequently, in step S15, the CPU 10 performs a normal photographing operation, that is, an exposure operation by controlling a shutter mechanism and the like based on the photometry result in step S11 described above. This exposure operation
This operation does not involve a flash emission operation by the flash device 24. Further, after processing such as a film feeding operation such as a film winding operation is performed, the process returns to a photographing standby state (return).

On the other hand, in step S12 described above, it is determined that the strobe light emission operation at the time of the exposure operation is necessary, and the process proceeds to step S18.
In step 8, the CPU 10 determines whether or not the strobe light emission operation is necessary at the time of the distance measurement operation based on the signal from the determination unit 4b of the A / D conversion unit 4 as in step S13 described above. Here, when it is determined that the strobe light emission operation at the time of the distance measurement operation is necessary, step S21 is performed.
In this step S21, the CPU 1
0 controls the strobe device 24 via the strobe control unit 23 so that the strobe light emission operation is performed in synchronization with the integration operation of the optical image signal by the integration means 4a of the A / D conversion unit 4 (integrated synchronous light emission processing). First light emission mode). And
The process proceeds to the next step S20.

If it is determined in step S18 that the strobe light emission operation at the time of the distance measurement operation is not necessary, the process proceeds to the next step S19.
At 19, the CPU 10 controls the strobe device 24 via the strobe control unit 23 to execute a strobe light emission operation that is not synchronized with the integration operation of the optical image signal by the integration means 4a of the A / D conversion unit 4 (integration). Asynchronous light emission processing;
(Second light emission mode), a strobe light emission operation and a distance measurement operation are executed. Then, the process proceeds to the next step S20. In step S20, a flash light emission operation (shooting synchronous light emission process) synchronized with the shooting operation is performed, and a series of processes is completed to return to the shooting standby state (return).

On the other hand, in the above-mentioned step S13, it is determined that the strobe light emission operation at the time of the distance measurement operation is necessary, and the process proceeds to step S16.
In step S6, a process similar to the process in step S21 described above, that is, an integral synchronous light emission process (first light emission mode) for synchronizing the light image signal integration operation and the strobe light emission operation is performed, and then in step S17, After performing a photographing operation (synchronous photographing light emission processing) by controlling the strobe device 24 so as not to synchronize the exposure operation and the strobe light emission operation, a series of processing is terminated, and the process returns to the photographing standby state (return).

By the way, when a photograph is taken using the strobe device 24, a so-called red-eye phenomenon may occur in which the eyes of a subject or the like become red on a photograph taken. As a technical means for suppressing this, for example, there is a technical means relating to so-called pre-emission in which strobe light is continuously emitted prior to an actual exposure operation.

In the range finder of the camera according to the present embodiment, as described above, the strobe light emission operation is performed during the range finder operation which is performed prior to the exposure operation. Therefore, if the strobe light emission operation for irradiating the auxiliary light for the distance measurement operation is incorporated as a part of the pre-emission operation for reducing the red-eye effect, the same usability as a conventional camera can be obtained. Can be done without any discomfort.

The timing of the flash emission operation in this case is as shown in FIG. That is, FIG. 10A shows the timing of normal pre-emission. As shown in FIG. 10A, normal pre-emission is performed prior to strobe light emission (main emission) during an exposure operation, and light emission is continuously performed a plurality of times at short intervals.

FIG. 10B shows the light emission control timing of the flash device in the camera of the present embodiment. In this case, at the beginning of the period during which the conventional pre-emission operation is performed, the auxiliary light irradiation for the distance measurement operation is performed, and after the pre-emission operation is continuously performed, the exposure operation is performed. The main light emission is performed.

As described above, according to the first embodiment, when the strobe light emission operation is required at the time of the exposure operation in accordance with the surrounding brightness at the time of photographing, the operation is performed prior to the exposure operation. In order to ensure the accuracy of the distance measurement operation, control is performed so that the auxiliary light irradiation using the strobe device 24 is always performed. If a series of photographing operations involves a strobe light emission operation, the light emission operation is always performed twice during the distance measurement operation and the exposure operation. There is no misunderstanding that the stroboscopic light emission operation during the distance measurement operation is the same as the strobe light emission operation during the exposure operation. Therefore, it is possible to prevent a photographing error or the like and reliably obtain a photographing result without failure.

Furthermore, if the auxiliary light irradiation (flash emission) operation for the distance measurement operation is taken in during the pre-emission operation for reducing the red-eye phenomenon, both the operator and the subject become uncomfortable. , And the feeling of use of the camera can be further improved.

By the way, as shown in the above-described first embodiment, when the auxiliary light irradiation for the distance measuring operation is performed as a part of the pre-light emitting operation performed prior to the exposure operation, surrounding light is emitted. An appropriate amount of auxiliary light irradiation (an appropriate level of irradiation) according to the brightness can be realized by, for example, controlling the number of times of emission of the auxiliary light.

When the number of times of light emission during the distance measuring operation is controlled as described above, the brightness of the surrounding environment is different depending on whether the distance (L) to the subject is short or long. Even under the same conditions, the number of times the auxiliary light is emitted during the distance measurement operation may change. That is, when the auxiliary light is irradiated, the amount of light that is reflected by the subject and enters the light receiving lenses 1a and 1b is smaller when the subject is at a long distance than when the subject is at a short distance. . Therefore, since the obtained optical image signal is relatively reduced, the integration time until reaching the appropriate level is also increased. On the other hand, in the case of a subject at a short distance, an optical image signal of an appropriate level may be obtained by, for example, one integration operation.

For example, FIG. 11 is a diagram showing an integrated waveform of an output (optical image signal) of a sensor array in a normal camera, and is an example showing a relationship between a subject distance, light emission, and the number of integrations. In this case, as shown in FIG. 11A, the light image signal of the subject obtained by the integration operation when the strobe light emission operation is performed twice is performed at a predetermined subject distance as shown in FIG. 11B. When the level reaches the appropriate level, for a subject located at a distance shorter than this, the integration amount of the optical image signal at the appropriate level is exceeded by the two integration operations, and the circuit is saturated. In other words, if the integration amount reaches an appropriate level by one integration operation, it is natural that the integration amount exceeds the predetermined appropriate level if the integration operation is performed twice.

As described above, when the amount of light emission of the auxiliary light is changed to control the light emission amount of the strobe device 24 in accordance with the change of the surrounding environment and the subject distance, the photographer needs to The fact that the number of times the strobe light is emitted is different every time a photographing operation is performed may cause complication, which may hinder the usability of the camera. In addition, since the integration time differs depending on the situation, the execution time of the distance measurement operation itself also changes.

Therefore, in order to solve such a problem, in the second embodiment of the present invention, the light emission amount is adjusted by controlling the light emission time of the strobe light emission operation performed at the time of the distance measurement operation, and the auxiliary light amount is adjusted. Although the number of light emission is not changed, the integration amount is adjusted to increase or decrease.

FIG. 12 shows an integrated waveform of the output (optical image signal) of the sensor array of the distance measuring device in the camera of the present embodiment, and shows the relationship between the subject distance, the light emission and the number of integrations. 12A and 12B show examples where the subject is at a short distance, and FIGS. 12C and 12D show examples where the subject is at a long distance. The configuration of the camera of the present embodiment is basically the same as that of the above-described first embodiment. Therefore, for details of each component,
Please refer to FIG.

In this embodiment, the number of strobe light emission operations performed prior to the distance measurement operation is four (FIG. 1).
2 (a) and (c)). In this case, FIG.
As shown in (a) and (b), when the subject is at a short distance, the integrated signal reaches an appropriate level by one strobe light emission operation. The light emission operation is performed only by the light emission amount Δt which is reduced with respect to the light emission amount, that is, dummy light emission is performed. This dummy light emission is performed for the second to fourth times, but the integration amount due to this is very small and does not greatly exceed the appropriate level.

On the other hand, when the subject is at a long distance, the normal strobe light emission operation is performed four times, as shown in FIGS. By these four strobe light emission operations, the integrated signal sequentially increases and reaches an appropriate level.

As described above, when the subject is at a short distance, the strobe light emission after the appropriate level of integration amount is secured is set as the dummy light emission. A so-called energy-saving design that suppresses the current flow is realized. Therefore, the integration amount can be adjusted without changing the number of times of light emission depending on the subject distance.

Next, the operation of the camera of the present embodiment at the time of the photographing operation will be described with reference to the flowchart of FIG. First, in step S26, a variable n indicating the number of times of light emission by the strobe device 24 is initialized (n = 1), and in the next step S27, integration for the distance measurement operation is started. Subsequently, in step S28, the CPU 10 determines whether or not the amount of integration within a predetermined time period is small (small) based on the signal from the determination unit 4b of the A / D conversion unit 4 to perform measurement. It is determined whether or not a strobe light emission operation at the time of the distance operation is necessary. Here, if it is determined that a sufficient amount of integration can be secured and that the strobe light emission operation during the distance measurement operation is not necessary,
On the other hand, when it is determined that the amount of integration is small and the strobe light emission operation at the time of the distance measurement operation is necessary, the process proceeds to the next step S29.

In step S29, after the first strobe light emitting operation is performed, in the next step S30, the variable n of the number of times of light emission is incremented (n + 1), and the process proceeds to the next step S31.

In step S31, it is determined whether or not the integral has sufficiently reached a predetermined appropriate level. This determination is also made based on the determination unit 4b of the A / D conversion unit 4 by the CPU.
10 does. Here, when it is determined that the integral amount is sufficient and the predetermined appropriate level has been reached, the process proceeds to step S36, in which the integral operation end process is performed, and the next step S37 is performed. In the above, it is set that dummy light emission is performed by performing a light emission time switching process. Next, the process proceeds to step S32.

On the other hand, if it is determined in step S31 that the integral amount is not sufficient and does not reach the predetermined appropriate level, the process proceeds to the next step S32. It is determined whether or not the variable n = 4 indicating the following. Where the variable n ≠
If the number is determined to be 4, the process returns to the above-described step S29, and the subsequent processes are repeated.

If it is confirmed in step S32 that the variable n = 4 for the number of times of light emission,
The process proceeds to the next step S33, and this step S33
After performing the termination processing of the integration operation, the process proceeds to step S34.

As described above, even if it is determined in step S28 that the amount of integration is sufficient without performing the strobe light emission operation, the process proceeds to step S33, and the integration end process is performed in step S33. Is executed, and the process proceeds to the next step S34.

In step S34, the CPU 10
An autofocus operation of controlling the focus lens 22 via the focus control unit 21 and moving the focus lens 22 to the focus position is performed. Next, in step S35, the CPU 10
Performs an exposure operation by controlling a shutter mechanism or the like (not shown) based on a photometry result by the photometry unit 25 (see FIG. 1) that has been executed in advance (shutter control processing). Thus, the sequence of the series of photographing processing ends (return).

As described above, according to the second embodiment, when the strobe light emission operation is performed prior to the distance measurement operation, the light image necessary for the distance measurement operation is independent of the subject distance and the photographing environment. When the signal is obtained, the light emission time is controlled so as to be shortened, so that a predetermined number of light emission times (four times in the present embodiment) is always performed, and then the focusing operation (lens control processing) is performed. ) And an exposure operation (shutter control processing). Therefore, the first
In the same manner as in the embodiment, the usability of the camera is not spoiled, and the photographer or the person who is the subject mistakes the strobe emission operation for the distance measurement operation from the strobe emission operation at the time of the exposure operation. There is nothing to do.

Next, a third embodiment of the present invention will be described.
This will be described below. FIG. 14 is a block diagram showing a configuration of the camera according to the present embodiment. The camera of this embodiment is
Basically, the configuration is substantially the same as that of the above-described first embodiment, except that a sensitivity switching unit 26 is newly provided. Other configurations are completely the same as those of the first embodiment. Also, in this figure, in order to avoid complication of the drawing, only members related to the present invention are shown as in FIG. 1, and other components are omitted.

The integration means 4a of the A / D converter 4 in this embodiment can take at least two types of integration. In other words, the integration modes of the integration means 4a include a high sensitivity mode in which the integration amount is set to be large for images having substantially the same brightness, and a low sensitivity mode in which the integration amount is set to be small. There are two modes (two modes), and the integration operation can be performed according to each mode. Further, a sensitivity switching means 26 is provided for switching between the high sensitivity mode and the low sensitivity mode according to the shooting environment.

FIG. 15 is a diagram showing a change in the amount of integration in each sensitivity mode. As shown in FIG. 15, when light beams having substantially the same intensity enter the sensor arrays 2a and 2b, the integral amount in the high sensitivity mode is set to be larger than the integral amount in the low sensitivity mode. Is set.

The switching of the integration mode of the integrating means 4a is performed by the sensitivity switching means 26 controlled by the CPU 10. FIG. 16 is a diagram schematically showing components related to the sensitivity switching means 26. As shown in FIG. 16, the sensitivity switching means 26
By performing on / off control by the PU 10, the capacity of the integrating means 4a including the capacitors 4x and 4y for integrating the photocurrent output from the sensor arrays 2a and 2b is switched, or the current to the integrating means 4a is amplified. You can do it. Thereby, the integration means 4a
Can be switched.

In the example shown in FIG. 16, when the sensitivity switching means 26 is turned on, the capacity of the integrating means 4a is added by the capacity of the capacitor 4y to set the low sensitivity mode. ing.

The operation of the camera according to the present embodiment having the above configuration at the time of the photographing operation will be briefly described as follows. First, integrate in the high sensitivity mode,
When the optical image signal is saturated by one flash emission operation, the mode is switched to the low sensitivity mode, and the flash emission operation is performed again. In this case, a more appropriate optical image signal can be obtained by performing switching control so as to shorten the flash emission time.
By performing such control, it is possible to emit strobe light of an amount of light that is optimal for each sensitivity mode.

Also, by checking the amount of integration by the first strobe light emission operation and controlling the light emission time of the second strobe light emission operation according to the result, the result of integration performed by the second and subsequent strobe light emission operations is as follows: This prevents erroneous distance measurement or the like caused by exceeding a proper integration amount and becoming saturated. In other words, if the integral amount made by the first strobe light emission operation becomes approximately half or more of the appropriate level of integral amount, the same amount of light emission operation is performed at the time of the second strobe light emission operation. It is clear that the appropriate amount will be exceeded. Therefore, control is performed to switch the light emission time during the second strobe light emission operation to be shorter than the light emission time during the first strobe light emission operation. In this way, the sensitivity and the light emission amount are controlled little by little, and an accurate integration amount is always secured for any subject (scene), so that a more accurate distance measurement operation can be realized.

The operation of the camera according to the present embodiment during a photographing operation will be described in more detail with reference to the flowchart of FIG. First, in step S41, a variable n indicating the number of times of light emission by the strobe device 24 is set, and in the next step S42, the CPU 10
To set the sensor sensitivity to the high sensitivity mode, and in step S43, the integration operation is started. Subsequently, in step S44, the CPU 10
To control the strobe device 24 to perform a strobe light emission operation based on a reference light emission amount in a preset high sensitivity mode. Note that the light emission time T = T1 at this time. As a variable for controlling the light emission time T, a guide number G may be used to control the light emission amount to be increased or decreased.

Next, in step S45, the variable n of the number of times of light emission is decremented (n-1), and in the next step S46, it is confirmed whether or not the integration amount is saturated. Here, when it is confirmed that the integration amount is not in the saturated state, the process proceeds to step S47. If it is confirmed that the integration amount has reached the saturated state, the process proceeds to step S59, where the integration is stopped (stopped) in step S59, and in step S60, a predetermined value is determined. Wait for time (W
AIT). When this predetermined time has elapsed, step S61 is executed.
Proceed to processing.

In step S61, it is determined whether or not the sensitivity mode needs to be switched. Here, if it is determined that the sensitivity switching is not necessary, the process proceeds to step S65. If it is determined that the sensitivity switching is necessary, the process proceeds to the next step S62, in which the CPU 10 controls the sensitivity switching means 26 to switch the sensor sensitivity to the low sensitivity mode. In step S63, the integration operation is started again.

Next, at step S64, the CPU 1
A value of 0 controls the strobe device 24 via the strobe control unit 23 to perform a strobe light emission operation based on a reference light emission amount in a preset low sensitivity mode. Note that the light emission time T = T3 at this time.

Next, in step S65, the variable n of the number of times of light emission is decremented (n-1), and in the next step S66, the integration amount is compared with a predetermined value set in advance. Note that the predetermined value in this case is an intermediate value of the appropriate level. That is, the process performed here is a process of checking whether or not the integration amount by the first strobe light emission operation in the low-sensitivity mode has become substantially half or more of the integration amount of the appropriate level.

In step S66, when the integration amount is smaller than a predetermined value (an intermediate value of an appropriate level), the process proceeds to step S49 described later. When the integration amount is larger than the predetermined value, the process proceeds to the next step S67, and in this step S67, after the variable T of the light emission time is reset to the variable T4 of a short light emission time. Similarly, the process proceeds to step S49 described later.

On the other hand, in the above-mentioned step S46, it is confirmed that the integral amount is not in a saturated state, and
When the process proceeds to step S47, in step S47, the integration amount is compared with a predetermined value set in advance. In addition,
The predetermined value in this case is an intermediate value of the appropriate level. In other words, the process performed here is a process of confirming whether or not the integration amount by the first strobe light emission operation in the high sensitivity mode has become substantially half or more with respect to the integration amount of the appropriate level.

In step S47, if the integral value is smaller than the predetermined value (intermediate value of the appropriate level), the process proceeds to step S49. On the other hand, when the integration amount takes a value larger than the predetermined value, the next step S4
In this step S48, the variable T of the light emission time is reset to the variable T2 which is a short light emission time, and the process proceeds to the next step S49.

After waiting (WAIT) for a predetermined time in step S49, in the next step S50,
The CPU 10 controls the strobe device 24 via the strobe control unit 23 to perform a strobe light emission operation for a light emission time T (= T2 or T4). Then, in step S51, the variable n of the number of times of light emission is decremented (n-1).
Then, in the next step S52, it is confirmed whether or not the number of times of light emission n = 0, that is, whether or not the flash light emission operation has been performed a predetermined number of times. Here, if it is confirmed that the variable n = 0, step S5
The process proceeds to the process 4, and when it is confirmed that the variable n = 0 (variable n ≠ 0), the process proceeds to the next step S53.

In step S53, it is confirmed whether or not the integration amount has become substantially equal to a predetermined value of a predetermined appropriate level. Here, if it is determined that the integration amount has not reached the appropriate level value, the process returns to step S49, and the subsequent processes are repeated. When it is confirmed that the integration amount has become substantially equal to the appropriate level value, the process proceeds to the next step S54. In this step S54, after a series of integration operations are completed, the next step S55 is performed.
, It is confirmed again whether or not the variable n = 0. Here, when it is confirmed that the variable n = 0, a series of sequences is ended (END).

If it is confirmed in step S55 that the variable n is not 0 (variable n ≠ 0), the process proceeds to the next step S56. In this step S56, a dummy light emission operation is performed. This dummy light emission operation is performed by an extremely short light emission time T5.

In the next step S57, the variable n of the number of times of light emission is decremented (n−1). In the next step S58, it is confirmed again whether or not the variable n = 0. When it is confirmed that it is 0,
A series of sequences ends (END). Also, the variable n
If it is determined that ≠ 0, the process returns to step S56, and the subsequent dummy light emission process is repeated until the variable n = 0.

As described above, according to the third embodiment, the sensitivity switching means 26 is provided, and the form of the integration operation by the integration means 4a according to the brightness of the subject (sensitivity mode).
Is switched, it is possible to acquire a more appropriate optical image signal, and it is possible to secure a more accurate distance measurement accuracy.

Further, the strobe light emission time is controlled in accordance with the integration amount of the optical image signal.
Since the integration operation is stopped, and even after the integration operation is stopped, the strobe light emission operation is performed for the set number of times of light emission, so that operability and usability are not impaired.

Next, a fourth embodiment of the present invention will be described below. The camera of each of the above-described embodiments is configured to include a passive type distance measuring device (first distance measuring means). In this passive type distance measurement method,
For example, there is a drawback that a subject (scene) with low contrast may not be able to measure distance. Therefore, in the present embodiment, an active-type distance measuring device (second distance measuring device) is further provided in parallel, and even if the passive-type distance measuring device cannot measure the distance, the distance to the subject can be reliably increased. The distance can be determined.

FIG. 18 is a block diagram showing the structure of a camera according to the fourth embodiment of the present invention. In this figure, as in FIG. 1, in order to avoid complication of the drawing, only members related to the present invention are shown, and other components are omitted. Further, the camera of the present embodiment is configured by adding an active type distance measuring unit to the configuration of the above-described first embodiment. Therefore, the same components as those of the above-described first embodiment are denoted by the same reference numerals shown in FIG. 1 and the description thereof is omitted.

The camera according to the present embodiment, as shown in FIG. 18, receives light beams 1a and 1b for condensing the subject light beam, and receives and photoelectrically converts the subject light beam transmitted through the light receiving lenses 1a and 1b to form an optical image. Sensor array 2a that generates signals
2b and an A / D including an integrating means for converting the outputs (analog signals) of the sensor arrays 2a and 2b into digital signals and integrating the digitized optical image signals.
A conversion unit 4; a calculation unit 5 for performing a correlation calculation or the like of image shift amounts of optical image signals obtained by the two light receiving lenses 1a and 1b and the two sensor arrays 2a and 2b; and an A / D conversion unit 4
An output unit 7 serving as an interface unit for receiving the output of the CPU 10 and outputting it to the CPU 10, a stationary light removing circuit 35 for removing a stationary light component from the optical image signal received and photoelectrically converted by the sensor arrays 2a and 2b, Photometry unit 2 that operates
5, a distance measuring unit 100, a CPU 10 as a control means for controlling the entire camera, a light emitting control means 31, a light emitting diode (LED) 32, and a light emitting element which constitute a part of the active type distance measuring means. A projection unit including a lens 33 and the like; a strobe light emitting unit including a strobe control unit 23 and a strobe device 24; a focusing control unit including a focusing control unit 21 and a focus lens 22; a shutter control unit 8 and a shutter mechanism 9 and an exposure control unit including the photometric unit 25 and the like.

The CPU 10 is controlled via a light emission control means 31. The light emission control means 31 controls the LED 32 to emit infrared light. The light emitted by the LED 32 is projected toward a subject via the light projecting lens 33.

The operation section 5 is formed by a hard logic circuit or the like. The A / D converter 4 is a circuit for converting output signals (analog signals) of the sensor arrays 2a and 2b into digital signals, and has a function of storing information such as conversion data. . The output circuit 7 is means for transmitting and outputting various data such as a signal digitized by the A / D converter 4 by serial communication to the port means 19 of the CPU 10.

The CPU 10 includes a port means 19 composed of a serial communication port, a terminal for controlling each function of the camera, etc., a register 18 for controlling the port means 19, an arithmetic register 14, and various arithmetic operations. Processing means 17 for performing processing and the like; and RA such as a non-volatile memory for temporarily storing data obtained as a result of the calculation processing.
M15, a ROM 16 storing a program such as a command group for various controls by a predetermined algorithm, and the like.

The port means 19 includes a focus control section 21 for controlling the movement of the focus lens 22, a shutter control section 8 for controlling the exposure amount by controlling the shutter mechanism 9, and a light emission of the strobe device 24. A flash control unit 23 for controlling the amount, the number of times of light emission, the light emission timing, and the like;
An electrically rewritable ROM or the like is electrically connected to an EEPROM 34 or the like in which a correction coefficient for correcting a manufacturing error or the like that differs for each camera is stored.

The port 19 moves the focus lens 22 in the direction of the optical axis via the focus control means 21 to perform automatic focus adjustment based on the distance measurement result by the distance measurement device. Further, the shutter mechanism 9 is driven and controlled via the shutter control unit 8 so that an appropriate exposure is performed based on the photometric result of the photometric unit 25.

As described above, in the EEPROM 34, when manufacturing the camera, correction coefficients for correcting various errors caused by variations in dimensional errors of components and variations in assembling accuracy are previously stored. It is remembered. Therefore, the CPU 10
Various controls are performed with reference to the correction data stored in the OM 34.

The operation of the camera according to the present embodiment having the above-described configuration when an active distance measurement operation is performed will be briefly described. When the photographer operates the release SW 20, a release signal is generated from the release SW 20. Upon receiving this release signal, the CPU 10 sends a control signal to the light emission control means 31 via the port means 19.
Then, the light emission control means 31 drives the LED 32 to emit light. When the LED 32 emits light, the light beam passes through the light projecting lens 33 and is projected toward the subject 6. Then, the reflected light beam reflected by the subject 6 enters the light receiving lens 1b and is received by the sensor array 2b disposed behind the light receiving lens 1b. The sensor array 2b includes a line sensor or the like as described in the above-described first embodiment, photoelectrically converts a received light beam of a subject image into an electric signal, and converts the light image signal into an A / A signal.
Output to the D conversion unit 4.

In this case, the light receiving position on the sensor array 2b can be determined more accurately by removing components other than the signal light, so-called stationary light, from the reflected light flux of the LED 32 received by the sensor array 2b. . Therefore, a stationary light removing circuit 35 is provided. The light receiving position of the subject light beam to the sensor array 2b is identified by comparing the light image signals before and after the light emission of the LED 32 and obtaining the difference between the two. From this light receiving position, a reference position on the sensor array 2b, that is, an interval x between the optical axis of the light receiving lens 1b and the intersection of the sensor array 2b, an interval between the light projecting lens 33 and the light receiving lens 1b, that is, a base line length B, Focal length f of light receiving lens 1b
The subject distance L can be obtained from

In the camera according to the present embodiment, the active distance measuring means and the passive distance measuring means are switched according to the environmental conditions such as the subject (scene), the subject distance, and the surrounding brightness. A distance movement can be performed. For example, it is difficult to measure the distance of an object at a long distance by an active distance measuring unit, while it is difficult to measure the distance by a passive distance measuring unit when the object is dark or has low contrast.

However, in the present invention, as described in each of the above embodiments, by performing the distance measurement operation with strobe light emission, even a passive distance measurement means can reliably measure a dark object. I can do it. Therefore, in the present embodiment, for a subject at a long distance, a passive distance measuring unit using the auxiliary light of the strobe device 24 is used even when the surrounding environment is dark. Further, the passive type distance measuring means can measure the distance over a relatively wide area in the photographing screen.

Since the auxiliary light (irradiation light) from the strobe device 24 can normally irradiate the entire photographing screen, the strobe light emitting operation can be performed even when performing a distance measuring operation around the screen. Is used.

On the other hand, if the subject is a short distance (in this embodiment,
In the case where the distance is specified based on the object distance L = 4 m) or near the center of the photographing screen, and the desired object has a low contrast, the active measurement is performed. We use distance means.

FIG. 19 is a conceptual diagram showing a photographing screen frame 41 in the camera of the present embodiment, which shows a distance measuring area 41a when a passive distance measuring means is used and a distance measuring area 41a when an active method is used. It is a figure showing distance area 41b, respectively. As shown in FIG. 19, the passive type distance measuring means is set such that distance measurement can be performed in a relatively wide area as compared with the case of using the active type distance measuring means.

FIG. 20 is a flowchart showing the operation of the camera according to the present embodiment during a shooting operation. First, when the operator turns on the main power supply (not shown) of the camera or the like, the camera is brought into a shooting preparation state, and when the release SW 20 is operated to generate a release signal, step S70 is performed.
In, the CPU 10 controls the photometric unit 25 to execute a normal photometric operation. Next, in step S71,
A distance measurement operation using the active method is performed. In the next step S72, the result of the distance measurement in step S71 is confirmed. Here, it is confirmed whether or not the subject distance L has exceeded 4 m. Here, if the subject distance L is not greater than 4 m, that is, if the subject distance is a short distance of 4 m or less, the process proceeds to step S83,
In step S83, a focusing operation is performed based on the result of the active distance measurement performed in step S71. The focusing operation performed here is performed by the CPU
Reference numeral 10 denotes an operation of driving the focus lens 22 via the focus control unit 21 to move the lens 22 to a predetermined position (focus control processing). Then, the process proceeds to step S82. In this step S82, the shutter control unit 8 drives and controls the shutter mechanism 9 based on the photometry result executed in step S70 to perform an exposure operation (shutter control process). . Thereafter, a series of sequences is completed and the process returns to the shooting standby state (return).

On the other hand, if the subject distance L> 4 m in the above step S72, the next step S73
Then, the result of the distance measurement in step S71 is confirmed again. Here, the subject distance L is 6 m
Is checked to determine whether or not the number has been exceeded. If the subject distance L is not greater than 6 m, the process proceeds to step S84. If the subject distance L is greater than 6m, the process proceeds to the next step S74.

More specifically, in the confirmation of the distance measurement result in the above-mentioned steps S72 to S73, first, in step S72, if the subject distance L is greater than 4 m, in the case of a short distance, an active type distance measuring means is used. In the case of a long distance (L> 4 m), the distance is set to use a passive distance measuring means.

Next, in step S73, different operations are performed on condition that the subject distance L> 6 m. That is, when the subject distance L is a long distance exceeding 6 m, in the processing after step S74, the distance measurement operation is performed in the low sensitivity mode in which the integration operation is performed by three times of the strobe light emission operation to obtain the optical image signal. I do it. When the subject distance L is 4 m to 6 m,
In the processing after step S84, the integration is terminated by one flash light emission operation, and the distance measurement operation is performed in the high sensitivity mode in which two dummy light emission operations are performed.

The details of the ranging operation in the low-sensitivity mode in steps S74 to S80 and the ranging operation in the high-sensitivity mode in steps S84 to S90 have been described in detail with reference to FIG. , Is simply described.

That is, when it is determined in step S73 that the subject distance L is a long distance exceeding 6 m, the integration operation is started in step S74, and the first strobe light emission is performed in step S75. After waiting for a predetermined time in step S76 (interval processing), in step S77, the second strobe light emission is performed, and after waiting for a predetermined time in step S78 (interval processing),
In step S79, the third (final) strobe light emission is performed, and then, in step S80, the integration operation ends. Then, the process proceeds to step S81.

On the other hand, if it is determined in step S73 that the subject distance L is not greater than 6 m, that is, if the subject distance L is determined to be 4 m to 6 m along with the determination in step S72, the integration operation is performed in step S84. Is started, and in step S85, the first strobe light emission is performed. Then, in step S86, the integration operation is completed. In step S87, the second strobe light emission (first dummy light emission) is performed. After waiting for a predetermined time in step S88 (interval processing), in step S89, After the third strobe light emission (second dummy light emission) is performed, step S9 is performed.
Wait for a predetermined time at 0 (interval processing),
Thereafter, the process proceeds to step S81. Then, after executing the processing of steps S81 and S82 as described above, a series of sequences is terminated and the process returns to the shooting standby state (return).

As described above, according to the fourth embodiment, the distance measuring means configured to switch between the distance measuring operation of both the active method and the passive method is provided. First, a distance measurement operation using the active method is performed. As a result, when the subject is at a short distance, focus control based on the active method distance measurement is performed as it is, while when the object is at a long distance, Since the passive distance measurement operation is performed again, focus control with higher accuracy can be performed, and a higher quality image photographing result can be obtained.

In the case of performing the passive range finding operation, the strobe light emission control and the sensitivity mode at the time of the integration operation are switched by utilizing the active range finding result. There is no need to perform complicated control such as checking the integration result during the integration operation as in the embodiment. Therefore, a series of sequences can be further simplified.

In a camera including passive type distance measuring means and active type distance measuring means, the following fifth embodiment can be considered. That is, the camera according to the fifth embodiment of the present invention first performs a distance measurement operation by the active method to detect the amount of infrared light reflected by the object projected from the LED 32. Based on the result, control is performed so as to switch the flash emission time (auxiliary light irradiation time) in the passive distance measurement operation. Other configurations are the same as in the above-described fourth embodiment.

FIG. 21 is a diagram showing the difference between the respective integration amounts in the high sensitivity mode and the low sensitivity mode when the flash emission amount is constant in the distance measuring means of the camera of the present invention.

When the strobe light emission amount is constant as shown in FIG. 21 (a), that is, the integral amount for the same strobe light emission time [T] is in the high sensitivity mode as shown in FIG. 21 (b). In the low-sensitivity mode, on the other hand, the level is below the appropriate level.

In such a relationship, the strobe light emission time is controlled so that, for example, as shown in FIG. 21 (c), the strobe light emission time is half of the light emission time [T] of FIG. 21 (a). When the time is [T / 2], as shown in FIG. 21D, the integration amount in each mode also changes.

Therefore, if the strobe light emission time is controlled to perform a plurality of strobe light emission operations,
The amount of strobe light emission can be controlled in at least four steps, and thus can be controlled so that an appropriate level of integration amount can be easily obtained.

Here, FIG. 22 shows a change in the amount of integration when a normal camera performs two flash operations with a constant flash emission time, and FIG. 23 shows the control of the flash emission time. It is a figure showing change of the amount of integration at the time of performing light emission twice.

As shown in FIG. 22 (a), in the normal case, when the strobe light emission operation does not reach the proper level slightly even in the high sensitivity mode, the same operation is repeated again. (The same amount of strobe light in the high sensitivity mode), the integrated amount may exceed an appropriate level.

However, as shown in FIG. 23 (a), even if the integration amount does not reach the appropriate level in the first flash emission operation, the second flash emission operation is performed under different conditions, that is, in the low sensitivity mode. If the switching is performed to perform the strobe light emission operation in a short strobe light emission time, a proper level of integration amount can be obtained.

As described above, in the present embodiment, by controlling the sensitivity mode at the time of the integration operation and the strobe light emission time at the time of strobe light emission according to the state of the subject, finer control of the integration amount can be performed. Therefore, a highly accurate distance measurement result can be obtained.

FIG. 24 is a flowchart showing a flow of an operation during a photographing operation in the camera according to the fifth embodiment of the present invention. First, the operator operates the main power supply (not shown) of the camera.
The camera is ready for shooting by inputting etc.
When the release switch 20 is operated to generate a release signal, the CPU (10) receives the signal and controls the photometric unit 25 to execute a normal photometric operation in step S91. Next, in step S92, an active distance measurement operation is performed.

In the next step S93, it is determined whether the amount of reflected infrared light received during the active distance measurement operation in step S92 is large or small. Here, when it is determined that the amount of reflected infrared light is large, the process proceeds to step S95, and when it is determined that the amount of reflected infrared light is small,
The process proceeds to step S94.

In the step S94, the CPU 10
Controls the strobe device 24 via the strobe control unit 23 to perform the strobe light emission operation and the integration operation based on the reference light emission time variable = T1 in the preset high sensitivity mode, and then to the process in step S96. move on. Also,
In step S95, after performing the strobe light emission operation and the integration operation for the short light emission time T2, step S95 is performed.
Proceed to 96.

Then, in step S96, the CPU
Reference numeral 10 drives the focus lens 22 via the focus control unit 21 based on the result of the integration operation in steps S94 and S95 described above to move the lens 22 to a predetermined position (focus control processing).

Subsequently, in step S97, the CPU
In step (10), the exposure operation is performed by controlling the drive of the shutter mechanism (9) via the shutter control section (8) based on the photometry result executed in step S91 described above (shutter control processing). Thereafter, a series of sequences is terminated (return).

With this configuration, according to the fifth embodiment, for a dark subject (scene),
Using active distance measuring means that can execute distance measuring operation with higher accuracy, it is possible to perform integral control at the time of distance measuring operation by quick and accurate passive method, regardless of the brightness of the shooting environment. Thus, a high-speed and high-accuracy distance measurement operation can be performed more efficiently. In addition, a strobe device 24 used for performing a passive distance measurement operation is used.
The number of times the auxiliary light is emitted is always a predetermined number, so that the usability is not impaired.

[Supplementary Note] According to the above-described embodiment of the present invention, an invention having the following configuration can be obtained. (1) Integrating means for integrating an optical signal according to an image pattern of a subject, a distance measuring device for measuring the distance of the subject based on the integrated signal obtained by the integrating means, and determining the amount of integration A strobe means for projecting light intermittently, and integration control means for controlling the integrating operation of the integrating means and the strobe means in accordance with the integration determining means. The integration control means includes: a first emission mode in which emission control is performed so that the strobe emission control and the integration operation are synchronized with each other prior to photographing; and a second emission mode in which the strobe emission control is performed without synchronization with the integration operation. A camera having two modes, a light emission mode.

(2) In the camera described in Appendix 1,
The second light emission mode is a mode for shortening the light emission time.

(3) In the camera described in Appendix 1,
The second light emission mode is a mode that is activated when it is determined that light emission is necessary during photographing.

(4) Integrating means for integrating an optical signal according to the image pattern of the object, first distance measuring means for measuring the distance of the object using the integrated signal obtained by the integrating means, and light emitting means A distance measuring device comprising: a second distance measuring means for measuring the distance of the subject in accordance with the position of the reflected signal light from the light projecting means; an integral judging means for judging the amount of integration; And an integration control means for controlling the integration operation of the integration means and the flash means in accordance with the integration determination means. Switching between two modes, a first light emission mode in which light emission control is performed in synchronization with the integration operation and a second light emission mode in which the flash emission control is performed without synchronization with the integration operation. A camera having mode switching means for changing according to the result of the second distance measuring means.

(5) First determining means for determining whether or not strobe light emission is necessary at the time of photographing, second determining means for determining whether or not strobe light emission is necessary at the time of distance measurement, the first determining means or A camera having light emission control means for controlling light emission together with distance measurement timing and photographing timing when any of the second determination means determines that light emission is necessary.

[0148]

As described above, according to the present invention, an appropriate optical image signal can be obtained in a camera having a distance measuring device using a strobe device as a means for emitting auxiliary light. It is possible to obtain high-precision distance measurement results and realize flash control of the strobe device so that the light emission operation of the auxiliary light during the distance measurement operation and the light emission operation during the exposure operation can be clearly distinguished. It is possible to provide a camera that can prevent a photographing error or the like without a person or a person who is a subject misidentifying a light emission timing during an exposure operation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a camera according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a sum FF of a difference between a right sensor (R) and a left sensor (L) and a shift amount in the camera of FIG. 1;

FIG. 3 is a distribution diagram showing the magnitude of the output of each of sensors R1 to R6 of light incident on a sensor array in the camera of FIG. 1;

4 is a distribution of a left sensor output signal at a position shifted by a shift amount S determined by a relative position difference between light images incident on two sensor arrays and a pitch between each sensor in the camera of FIG. 1; FIG.

FIG. 5 is a diagram illustrating an example in which the output of each sensor after the correlation calculation process is shifted by a shift amount S in the camera of FIG.
The figure shown in the form which is easy to compare.

FIG. 6 is a flowchart showing a flow of a calculation performed inside the calculation control means.

FIG. 7 is a diagram showing an output signal of a sensor array in the camera of FIG. 1 and an integrated waveform thereof.

8 is a flowchart showing an outline of an operation flow at the time of a photographing operation in the camera of FIG. 1;

FIG. 9 is a flowchart showing details of the flow of an operation at the time of a photographing operation in the camera of FIG. 1;

FIG. 10 is a timing chart showing the timing of pre-emission control performed prior to an exposure operation.

FIG. 11 is a diagram illustrating an integrated waveform of an output (light image signal) of a sensor array in a normal camera, and is a diagram illustrating a relationship between a subject distance, light emission, and the number of times of integration.

FIG. 12 is a diagram showing an integrated waveform of an output (optical image signal) of a sensor array of a distance measuring device in a camera according to a second embodiment of the present invention, and showing a relationship between a subject distance, light emission, and the number of integrations.

FIG. 13 is a flowchart showing the operation of the camera of FIG. 12 during a shooting operation.

FIG. 14 is a block diagram showing a configuration of a camera according to a third embodiment of the present invention.

FIG. 15 is a diagram illustrating a change in an integration amount in each sensitivity mode in the camera in FIG. 14;

FIG. 16 is a view schematically showing components related to sensitivity switching means in the camera of FIG. 14;

FIG. 17 is a flowchart showing the operation of the camera of FIG. 14 during a shooting operation;

FIG. 18 is a block diagram showing a configuration of a camera according to a fourth embodiment of the present invention.

19 shows a shooting screen frame in the camera of FIG. 18,
FIG. 3 is a conceptual diagram showing a distance measurement area when a passive distance measurement unit is used and a distance measurement area when an active distance measurement unit is used.

FIG. 20 is a flowchart showing the operation of the camera of FIG. 18 during a shooting operation.

FIG. 21 shows a distance measuring means in the camera of the present invention.
FIG. 7 is a diagram illustrating a difference between each integration amount in a high sensitivity mode and a low sensitivity mode when a strobe light emission amount is fixed.

FIG. 22 is a diagram showing a change in the amount of integration when two light emission operations are performed for a fixed strobe light emission time in a normal camera.

FIG. 23 shows a camera according to a fifth embodiment of the present invention.
FIG. 9 is a diagram showing a change in an integral amount when two flashes are executed by controlling a flash emission time.

24 is a flowchart showing a flow of an operation at the time of a photographing operation in the camera of FIG. 23;

FIG. 25 is used in a process of interpolation calculation performed in the camera of each embodiment of the present invention [Equation 11].

FIG. 26 is used in a process of an interpolation operation performed in the camera of each embodiment of the present invention [Equation 12].

FIG. 27 is a block diagram schematically showing the configuration of a conventional passive type distance measuring apparatus.

[Explanation of symbols]

1a 1b Light receiving lens 2a 2a Sensor array 4 A / D converter 4a Integration means 4b Integration determination means 5 Calculation unit 6 Subject 8 Shutter control unit 9 ... Shutter mechanism 10... CPU (integral control means, first determination means, second determination means) 21... Focus control section 22... Focus lens group 23... Strobe control section (strobe light emission means, light emission control means) 24 strobe device (strobe light emitting means) 25 photometric unit (photometric means) 26 sensitivity switching means (mode switching means) 31 light emitting control means (light emitting means) 32 light emitting diode (LED; Light emitting means) 33 Light emitting lens (Light emitting means) 35 Steady light removing circuit

Continued on the front page F term (reference) 2H011 AA01 BA05 BB02 BB04 DA07 DA08 2H051 AA01 BB07 BB10 CC10 CC11 CC12 EB07 2H053 AA01 AA05 AB02 AB03 AD23 BA82 DA09

Claims (4)

[Claims] 1. A camera having an auto-focus device for focusing a subject on the basis of a subject image and a strobe light emitting device for supplementarily emitting light, a first method for determining whether or not the strobe light emitting device needs to emit light at the time of photographing. Determining means; second determining means for determining whether or not the strobe light emitting means needs to emit light during distance measurement; and at least one of the first and second determining means needs to emit light from the strobe light emitting means. And a light emission control means for controlling the light emission of the strobe light emission means during the photographing operation and the distance measurement operation. 2. A camera comprising an integrating means for integrating an optical signal corresponding to an image pattern of a subject, and a distance measuring device for measuring a distance to the subject based on the integrated signal obtained by the integrating means. Integration determining means for determining the amount of integration obtained by the above, strobe light emitting means for performing auxiliary intermittent light emission, integration operation of the integrating means and light emission of the strobe light emitting means based on the determination of the integration determining means. An integration control means for controlling an operation of the electronic flash, wherein the integration control means performs a light emission operation of the strobe light emission means in synchronization with the integration operation of the integration means prior to photographing; Control is performed so as to operate in one of the second light emission modes in which the light emission operation of the strobe light emission means and the integration operation of the integration means are performed without synchronization. Camera, characterized in that. 3. The camera according to claim 2, wherein the integration control means sets a light emission time shorter than that of the first light emission mode when controlling the second light emission mode. 4. An integrating means for integrating an optical signal corresponding to an image pattern of a subject, a first distance measuring device for measuring a distance to the subject by using the integrated signal obtained by the integrating means, and a measuring device for the subject. A light projecting means for projecting a light beam for distance,
A camera having a second distance measuring device for measuring a distance to the object by a signal based on a signal light reflected from the object; an integration judging means for judging an integral amount obtained by the integrating means; Strobe light emitting means for performing intermittent light emission; integration control means for controlling the integrating operation of the integrating means and the light emitting operation of the strobe light emitting means based on the determination of the integration determining means; and the second distance measuring device A first light emission mode in which the light emission operation of the flash light emitting means is synchronized with the integration operation of the integration means based on the distance measurement result, and the light emission operation of the flash light emission means and the integration operation of the integration means are synchronized. A mode switching unit for setting the mode to one of a second light emission mode performed without performing the operation.