JP2002287201A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera capable of controlling the emission of strobe light so that the optimum exposure can be obtained. SOLUTION: As for the electronic camera capable of recording image information wherein the optical image of an object is converted into an electric signal, the camera is provided with a strobe light emitting means 50 for illuminating the object, a 1st photometry means 40 for preliminarily emitting the strobe light from the strobe light emitting means before photographing and then measuring the light reflected by the object at the preliminary light emission, a 2nd photometry means 55 for measuring the light reflected by the object at the light emission of the strobe light emitting means in the midst of photographing, a photometry control means 40 for selectively switching the 1st photometry means and the 2nd photometry means in accordance with a photographing mode, and a stroboscope control means 40 for controlling so that the light emission of the strobe light emitting means may be finished by using the photometry result of either of the 1st photometry means or the 2nd photometry means based on the switching control by the photometry control means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera capable of continuously photographing a plurality of images.

[0002]

2. Description of the Related Art In an electronic camera, not only single shooting but also continuous shooting for continuously shooting a plurality of images and moving image shooting have become possible. In this case, when the subject is dark, it is necessary to shoot with the strobe emitting light. (Hereinafter referred to as "photometry") to obtain an appropriate light emission amount. There are two known photometric methods. The first photometric method is a method mainly used in a silver halide camera that performs photographing using a photographic film, and uses a photometric element provided on the front of the camera to measure strobe light hitting a subject. It is a method to do. In this method, since the strobe light during the photographing is measured, there is an advantage that the preliminary metering is unnecessary and the metering does not take much time. However, especially in the case of a short distance, accurate photometry may not be performed due to a parallax problem. The second photometry method is a method in which the strobe light is preliminarily fired before the actual photographing, the light amount from the subject is measured by the image sensor, and the appropriate light emission amount of the strobe light is set. FIG. 7 shows a schematic flow of photographing by this method. First, the first preliminary light emission is performed (step E).
1) Measure the brightness of the subject and store the brightness (step E2). Next, the light emission amount of the preliminary light emission is changed (usually, the light emission amount is made smaller than the first light emission), the second preliminary light emission is performed (step E3), the luminance of the subject is measured, and the luminance is stored. (Step E4). The measurement of the luminance of the subject by the preliminary light emission may be performed as many times as necessary. Then, based on the stored luminance of the subject, an appropriate main flash emission amount is calculated (step E5). Then, the main photographing is performed according to the calculated main light emission amount (step E6). In this method, photometry is performed by an image sensor for capturing an image. Therefore, although it takes time, there is no parallax compared to the first method, and high-precision photometry is possible. Furthermore, since the photo sensor is also used as the image sensor originally used for photographing, a special device is not required,
Contribute to downsizing and cost reduction. Therefore, the second method is often used in electronic cameras. But the second
In the method described above, since the preliminary light emission must be executed as described above, there is a problem that it takes time (for example, 0.5 seconds) until the actual photographing and a problem that the strobe light is wasted. . In addition, since it takes time (a predetermined time) for photometry by the pre-emission, there is also a problem that it cannot cope with a case where the subject is moving or a case of continuous shooting.
For this reason, conventionally, when performing high-speed continuous shooting,
Before taking the first image of the high-speed continuous shooting, photometry is performed by the second method, and the second and subsequent images are controlled so as to be set at the same light emission amount as the first image. This specific flow will be described with reference to FIG. FIG. 8 is a flowchart showing a conventional flash photography process. Normally, in the shooting mode,
The release switch is a two-stage switch, and performs AF (automatic focus adjustment) and AE (automatic exposure adjustment) in the first stage (first release) (steps F1 and F2). When the release switch is further pressed (second release) (step F3), actual shooting is performed. Here, when the AE determines that the light amount of the subject is insufficient (step F4), the electronic camera is controlled to perform strobe shooting, but in the electronic camera, dimming by normal preliminary flash is performed. . Step F4
In the case where a strobe is unnecessary, a normal photographing is performed (step F5). However, in the present invention, since the present invention relates to the case where a strobe is required, the following description will be omitted. Then, it is determined whether or not continuous shooting is performed (step F6). If the shooting is not continuous shooting, main shooting (referred to as "shooting by preliminary flashing") is performed as shown in FIG. 7 (step F7), and the process ends. In the case of continuous shooting, first, shooting using preliminary light emission is performed (step F).
8) Until the release switch is turned off (step F)
9), the actual photographing is performed under exactly the same light emission conditions (step F10). As described above, conventionally, in the case of the high-speed continuous shooting, the dimming in each shooting is not in time with the second photometry method, so that the shooting is performed until the end of the continuous shooting under the initially set condition (light emission amount). Done. Therefore, when the shooting conditions change during continuous shooting (for example, when the subject moves), the shooting is not necessarily performed under the optimal dimming conditions.

[0003]

As described above, in the conventional electronic camera, in the high-speed continuous shooting, the amount of strobe light emission set before the high-speed continuous shooting is used for the second and subsequent frames. An appropriate light emission amount is not always set for an image. In the case of continuous shooting, basically, a moving subject is often photographed. For example, when the subject moves away, it is expected that the subject will gradually become underexposed, and the subject approaches. In such cases, overexposure is expected. SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic camera capable of controlling strobe light emission so as to obtain an appropriate exposure.

[0004]

According to the present invention, there is provided an electronic camera capable of recording image information obtained by converting an optical image of a subject into an electric signal, comprising: a strobe light emitting means for illuminating the subject; First, preliminary light emission is performed by the strobe light emitting means, and first light metering means for metering reflected light from the subject due to the preliminary light emission, and reflected light from the subject caused by light emission of the strobe light during photographing are measured. A second photometric unit, a photometric control unit that selectively switches the first photometric unit and the second photometric unit according to a shooting mode, and the first photometric unit based on switching control by the photometric control unit. Strobe control means for terminating light emission by the strobe light emitting means using a photometric result of one of the photometric means and the second photometric means.

A preferred embodiment of the above electronic camera is as follows. In addition, each of the following embodiments may be applied independently or may be applied in an appropriate combination. (1) In the continuous shooting mode in which a plurality of images are continuously photographed, the photometry control unit performs photometry with the first photometry unit for the first image, and the second photometry unit for the second and subsequent images. Control to perform photometry with.

(2) In the continuous photographing mode for continuously photographing a plurality of images, the light measuring control means includes a first light measuring means and a second light measuring means in accordance with a time interval of the continuous photographing. Control so that photometry is performed by switching Here, when the time interval is equal to or more than a predetermined value, the first photometric means is used, and when the time interval is less than the predetermined value, the second photometric means is used. (3) In the continuous shooting mode, the light metering control means performs light metering by the first light metering means in low-speed continuous shooting and in the single photographing mode, and performs light metering by the second light metering means in high-speed continuous shooting in the continuous shooting mode. Control to do so.

(4) The photometry control means controls the second photometry means to perform photometry in a continuous shooting mode for continuously photographing a plurality of images.

In another electronic camera according to the present invention, an external strobe device having an external strobe light emitting means and an external photometric means can be mounted, and can record image information obtained by converting an optical image of a subject into an electric signal. A first control for terminating light emission by the external strobe light emitting means according to a control signal from a main body of the electronic camera, and a second control for terminating light emission by the external strobe light emitting means by the external light metering means. And an external strobe control means for selectively switching the control according to the shooting mode.

A preferred embodiment of the above electronic camera is as follows. In addition, each of the following embodiments may be applied independently or may be applied in an appropriate combination. (1) The external strobe control means terminates the light emission by the external strobe light emitting means by the first control in the case of the single photographing mode, and the second in the case of the continuous photographing mode.
Control for terminating light emission by the external strobe light emitting means.

(2) In the normal mode, the external strobe control means performs preliminary light emission by the external strobe light emitting means before photographing, and emits the external strobe light in accordance with the result of photometry of the object by the preliminary light emission. Control to end light emission by the means.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram of an electronic camera according to the present invention.

The optical image of the object passing through the lens 11 is
It is converted into an electric signal by an image sensor 12 such as a CCD or a CMOS sensor, and a digital image signal (hereinafter, referred to as an image signal) by an image sensor 13.
The image data is also converted into “image information” and temporarily stored in the volatile built-in memory 25. This built-in memory 25
Is a high-speed, for example, SDRAM (Synchronous)
sDynamic Random Access Me
memory), which is also used as a work area for image processing described later. The image processing circuit 15 performs processing such as conversion processing of color information of image information temporarily stored in the built-in memory 25 and conversion of the number of pixels. Then, the image information is subjected to various image processing in the image processing circuit 15 and, for example, J
PEG compressed, removable memory 2 such as smart media
Recorded as 0.

When displaying a photographed image, the LCD driver 31 controls the driving of the image display LCD 30 to display the image information after image processing.

When an image recorded in the detachable memory 20 is displayed, the image is expanded by the image processing circuit 15 and subjected to predetermined image processing.
The image recorded on the image display LCD 30 is displayed.

The CPU 40 reads a basic control program of the electronic camera from a non-illustrated non-volatile memory such as a flash memory or a ROM (Read Only Memory) to control the entire electronic camera.

The CPU 40 receives an input from the operation unit 46 including a cross key, a jump key, and a release button (not shown), and performs control according to the input. Further, the CPU 40 controls the power supply unit 52 to which power is supplied from the battery 53, and also manages the power supply of the entire electronic camera. Further, the CPU 40 controls the strobe control unit 51 according to an instruction from the operation unit 46 or an instruction from the automatic exposure adjustment circuit (AE) 14 to control the strobe light emitting unit 50.
Control of the light emission. Note that the preliminary light emission of the strobe light emitting unit 50 is also controlled by the strobe control unit 51 based on an instruction from the CPU 40.

In the electronic camera according to the present invention, a photometric element 55 is mounted.
The photometry result is output to U40, and control is performed so that the flash emission unit 50 stops emitting light based on the photometry result. The light emission of the strobe light emitting unit 50 may be terminated not only by the photometric element but also based on the result of the preliminary light emission as described above. The operation of the electronic camera according to the first embodiment of the present invention configured as described above will be described with reference to FIG. FIG. 2 is a flowchart showing a flow of the operation of the electronic camera according to the first embodiment of the present invention. The following embodiment will be described assuming that flash photography processing is performed. First, it is determined whether or not continuous shooting is performed (step A1). If the continuous shooting is not performed, the flash emission amount is set by preflash (light control), and flash shooting is performed based on the set flash amount (step A2). . Note that the flash photography based on the light control by the preliminary light emission is hereinafter referred to as “flash photography by the preliminary light emission”. In step A1, in the case of continuous shooting, flash photography by preliminary light emission is performed for the first time of continuous shooting (step A3). Then, continuous shooting is continued until the release is turned off (step A4). In step A4, if the release is kept on, the second and subsequent shootings are executed. However, the flash shooting using the preliminary light emission is not in time for the next shooting, so that the flash shooting is performed based on the photometry using the photometric element. Perform (Step A5). Hereinafter, the actual photographing is referred to as “flash photographing using a photometric element”. And
Returning to step A4, it is determined whether or not the release is in the on state. When the release is turned off, the photographing ends. As described above, in the case of continuous shooting, there is enough time for the first shooting even with the flash shooting with preliminary flash, so
In the second and subsequent shootings, the shooting is performed by switching to shooting using a photometric element, so that accurate photometry can be performed. Step A of the first embodiment described above.
In step 1, when it is determined that continuous shooting is performed, step A3 may be omitted, and flash photography may be performed using the photometric element in step A5.

A second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a flowchart showing the flow of the operation of the electronic camera according to the second embodiment of the present invention. First
In the embodiment, the photometry method is changed between the first shooting of the continuous shooting and the subsequent shooting, but in the present embodiment, even in the case of the continuous shooting, the case of the high speed and the case of the low speed Is used to switch the photometric method. In FIG. 3, the same parts as those in FIG. 2 are denoted by the same reference numerals. In FIG. 3, the steps up to step A4 are the same as those in FIG. In step A4, if the release remains in the ON state, it is determined whether or not high-speed continuous shooting is performed (step B1). In the case of high-speed continuous shooting, flash photography is performed using a photometric element (step B2). If the photographing is not performed, flash photographing is performed by preliminary light emission (step B3). In the present embodiment, unlike the first embodiment, even in the case of continuous shooting, in the case of low-speed continuous shooting, strobe shooting using preliminary flash is performed, so that the flash emission amount is set with high accuracy. it can. A third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of the operation of the electronic camera according to the third embodiment of the present invention. In the first and second embodiments, stroboscopic photographing is performed by preliminary light emission at least in the first photographing. In this embodiment, however, preliminary photographing or strobe photographing by the photometric element is performed from the beginning depending on the photographing mode. I'm trying to do it. In FIG. 4, first, it is determined whether or not continuous shooting has been performed (step C1). If not continuous shooting, flash photography with preliminary light emission is performed (step C2). If continuous shooting is performed in step C1, it is further determined whether or not high-speed continuous shooting is performed (step C1).
3) If it is not high-speed continuous shooting, flash photography with preliminary light emission (step C4) is continued until the release is turned off (step C5). In the case of high-speed continuous shooting in step C3, flash photography (step C6) using the photometric element is continued until the release is turned off (step C7). In each of the embodiments described above, the case where the strobe built in the electronic camera is used has been described. However, the same control can be performed when an external strobe is used. In the following embodiment, a case where an external strobe is used will be described. FIG. 5 is a schematic block diagram of an electronic camera according to the present invention when an external strobe device is used.
In FIG. 5, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted. In this case, it is assumed that no photometric element is mounted on the electronic camera body. Therefore, the preliminary light emission is performed by the external strobe light emitting unit, and the photometry by the photometric element is also performed by the external strobe device. Further, the strobe light emitting unit 50 and the strobe control unit 51 in FIG. 1 are respectively referred to as the internal strobe light emitting unit 50 and the internal strobe control unit 51 to distinguish them from those of the external strobe device 60, but their functions are exactly the same. Therefore, the same reference numerals are given. In FIG. 5, an external flash device 60 is connected to a CPU 4 of an electronic camera via an external interface (I / F) 45.
Connected to 0. The external strobe device 60 includes a power supply unit 65 that supplies power to each unit of the external strobe device 60,
Strobe control unit 6 for controlling light emission of strobe light emitting unit 62
1, a photometric element 63 for detecting the reflected light from the subject due to the emission of the strobe light emitting section 62, and a photometric circuit 6 for measuring the reflected light from the subject based on the detection result of the photometric element 63
4 is provided. Note that the basic functions from the flash control unit 61 to the photometric circuit 64 are the same as those mounted on the electronic camera in the first embodiment. The function of the external strobe device 60 is substantially the same as that of the strobe device provided in the electronic camera, but differs in the following points. In the case of performing the preliminary light emission by the strobe light emitting unit 62, it is necessary that all control can be performed on the electronic camera side. That is, both on and off of the strobe light emitting unit 62 are controlled by a control signal from the electronic camera (referred to as “TTL” mode). However, when the light amount of the strobe light emitting unit 62 is controlled by using the photometric element 63 mounted on the external strobe device 60, it is necessary to turn off the strobe light emitting unit 62 based on the signal of the photometric element 63. Therefore, the electronic camera controls ON of the strobe light emitting section 62 and controls the OFF of the external strobe device 60 (referred to as "AUTO" mode). This embodiment is an embodiment in which these modes are properly used depending on the shooting mode. FIG. 6 is a flowchart illustrating the operation of the electronic camera according to the fourth embodiment configured as described above. First,
Determine whether the camera is in continuous shooting mode (step D
1). If the mode is not the continuous shooting mode, strobe photographing using preliminary light emission is preferable, so the external strobe device 60 is set to the TTL mode (step D2). Then, flash photography by preliminary light emission is performed (step D3). Step D
In step 1, in the case of continuous shooting, the external flash device 60 is set to the AUTO mode (step D4), and the photographing by the photometric element 63 provided in the external flash device 60 (step D5) is performed until the release is turned off. (Step D
6) Perform. As described above, even when an external flash device is used, the on / off state of light emission from the external flash device is controlled by selecting an optimal metering method according to the shooting mode. Shooting can be performed by an appropriate photometric method according to the image. As described above, according to the present invention, since the photometry method is the most suitable method according to the shooting mode, it is possible to perform shooting using an appropriate photometry method according to the shooting mode. The present invention is not limited to the above embodiment of the present invention. In the above-described embodiment, an example in which the two types of photometry methods are appropriately combined according to the shooting mode has been described.
You may be able to change it. In addition, it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0019]

According to the present invention, the following effects can be obtained.

Since the two photometric means are selectively used according to the photographing mode, effective photometry is possible.
That is, at the start of photographing, high-precision photometry is performed by pre-emission, and during continuous shooting, photometry is performed in a short time by external photometry, thereby enabling high-speed continuous shooting while maintaining exposure accuracy. In high-speed continuous shooting, photometry is performed by an external photometric element, and in low-speed continuous shooting, photometry is performed by pre-emission. In high-speed continuous shooting, photometry is performed by an external photometric element. In the case of low-speed continuous shooting and single shooting mode, photometry is performed by pre-emission, so that photometry is performed according to shooting, and exposure accuracy can be maintained. When the external strobe device is mounted, the strobe control method is changed according to the shooting mode, so that strobe control according to the shooting mode can be performed. Also, there is an effect that a photometric element is not required in the camera.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an electronic camera according to the present invention.

FIG. 2 is a flowchart showing the flow of the operation of the electronic camera according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of operation of the electronic camera according to the second embodiment of the present invention.

FIG. 4 is a flowchart showing an operation flow of an electronic camera according to a third embodiment of the present invention.

FIG. 5 is a schematic block diagram of another electronic camera according to the present invention.

FIG. 6 is a flowchart showing a flow of an operation of the electronic camera according to the fourth embodiment of the present invention.

FIG. 7 is a flowchart showing the flow of flash photography using preliminary light emission.

FIG. 8 is a flowchart showing a conventional flash photography process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Lens 12 ... Imaging element 13 ... Imaging circuit 14 ... Automatic exposure adjustment circuit 15 ... Image processing circuit 20 ... Detachable memory 25 ... Built-in memory 30 ... LCD for image display 31 ... LCD driver 40 ... CPU 45 ... External interface 46 ... Operation Unit 50: Strobe light emitting unit (internal strobe light emitting unit) 51: Strobe control unit (internal strobe control unit) 52: Power supply unit 53: Battery 55: Photometric element 56: Photometric circuit 60: External strobe device 61: Strobe control unit 62: Strobe light emitting unit 63: photometric element 64: photometric circuit 65: power supply unit

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) // H04N 101: 00 H04N 101: 00 (72) Inventor Hiroyuki Watanabe 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. F term (reference) 2H002 AB04 CD07 CD13 DB05 DB06 2H053 AB11 AD12 AD23 2H054 AA01 5C022 AA13 AB15 AC03 AC42 AC69

Claims (8)

[Claims] 1. An electronic camera capable of recording image information obtained by converting an optical image of a subject into an electric signal, comprising: a strobe light emitting means for illuminating the subject; and a preliminary light emission by the strobe light emitting means before photographing;
First light metering means for metering reflected light from the object due to the preliminary light emission; second light metering means for metering light reflected from the object by light emission of the strobe means during shooting; and the first light metering A photometric control means for selectively switching the means and the second photometric means in accordance with a shooting mode; and any one of the first photometric means and the second photometric means based on switching control by the photometric control means. And a strobe control unit for terminating light emission by the strobe light emission unit using the photometric result of (1). 2. The electronic camera according to claim 1, wherein the photometry control means performs photometry with the first photometry means in a continuous shooting mode in which a plurality of images are continuously photographed. An electronic camera, wherein control is performed such that photometry is performed by the second photometry means for the second and subsequent sheets. 3. The electronic camera according to claim 1, wherein the photometric control unit is configured to shoot the first image in accordance with a time interval of the continuous shooting in a continuous shooting mode for continuously capturing a plurality of images. An electronic camera, wherein control is performed such that photometry is performed by switching between the photometry unit and the second photometry unit. 4. The electronic camera according to claim 1, wherein the light metering control means performs light metering by the second light metering means in low-speed continuous shooting in continuous shooting mode and in normal mode. An electronic camera, wherein control is performed so that photometry is performed by the first photometry unit in high-speed continuous shooting in a continuous shooting mode. 5. The electronic camera according to claim 1, wherein the photometry control means controls the second photometry means to perform photometry in a continuous shooting mode for continuously photographing a plurality of images. Electronic camera featuring. 6. An electronic camera to which an external strobe device having an external strobe light emitting means and an external photometric means can be attached and which can record image information obtained by converting an optical image of a subject into an electric signal. A first control for terminating light emission by the external strobe light emitting means according to a control signal from the main body of
An electronic camera, comprising: an external strobe control unit that selectively switches between a second control for terminating light emission by the external strobe light emitting unit by the external photometric unit according to a shooting mode. 7. An electronic camera according to claim 6, wherein said external strobe control means terminates light emission by said external strobe light emitting means by a first control in a single photographing mode, and switches to a continuous shooting mode. In this case, the electronic camera performs a control for terminating light emission by the external strobe light emitting means by a second control. 8. The electronic camera according to claim 6, wherein said external strobe control means includes:
An electronic camera, comprising: performing a preliminary light emission by the external strobe light emitting means before photographing; and performing control to terminate the light emission by the external strobe light emitting means in accordance with a result of photometry of the subject by the preliminary light emission.