JP2001056494A - Flash device, corresponding camera and image pickup device constituted thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flash device improved so that it can be used in common by digital cameras represented by the video camera recorder, the digital still camera and the like, the corresponding digital camera and an image pickup device constituted of them. SOLUTION: This flash device 33 is constituted so that light reflected from an object is received by a light receiving element 24 and flashlight is emitted toward the object from a light emission unit 26. Besides, it is provided with a communication means transmitting color temperature peculiar to its own flashlight to the camera side through a communication line 49 as color temperature information and obtaining light quantity information from the camera side, a control means setting the threshold value of emitted light quantity by using the light quantity information and controlling the flash light emitting time, and a light control means controlling the flash light level from the unit 26 according to the threshold value of the emitted light quantity based on the quantity of reflected light received by the element 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash device improved so that it can be used in common among digital cameras represented by a video camera recorder, a digital still camera, and the like, a corresponding digital camera, and a corresponding digital camera. The present invention relates to an imaging device to be configured.

[0002]

2. Description of the Related Art As an example of the configuration of a conventional digital camera, a digital camera 10 schematically shown in FIG. 3 will be described. Incident light input from the subject to the imaging lens 11 is converged by the imaging lens 11 and output to the charge-coupled device 12.

The charge-coupled device 12 is usually a CCD (ch)
arge coupled device)
The light incident on the elements arranged in an array is converted into an electric signal having an intensity corresponding to the brightness. The converted electric signal is converted into a digital signal by the analog / digital converter 13 and output to the image signal processing circuit 14.

[0004] The image signal processing circuit 14 has an analog /
The digital signal output from the digital converter 13 is converted into an image signal, and the converted digital image signal is output to the signal processing circuit 16.

The signal processing circuit 16 includes the image signal processing circuit 1
4 is converted into, for example, JPEG (J
point Picture Expert Group
The image of the subject is displayed on the liquid crystal display 18 via the LCD drive circuit 17 by performing data compression processing in a compression format such as p).

The converted digital signal is subjected to necessary processing such as compression in a signal processing circuit 16 to display an image of a subject on a liquid crystal display 18 and then written to a memory card 20 via a connector 19. And digitally recorded. Conversely, image data read from the memory card 20 via the connector 19 is transmitted to the signal processing circuit 16
The image is displayed on the liquid crystal display 18 via the CD drive circuit 17.

[0007] The operating section 21 allows not only shutter operation, but also operations such as setting of an aperture value, setting of a distance to a subject, setting of a shutter speed, and the like, and selection of photographing conditions by a selection operation on a menu screen for selecting various camera functions. Configuration,
The photographing information PI is selected by the control unit 2.
2 is transmitted.

The digital camera 10 has a built-in flash unit 23. The built-in flash unit 23 has a light receiving element 24 and an A / D converter that converts the reflected light from the subject detected by the light receiving element 24 from analog to digital. D converter 2
5, a light emitting unit 26 for flashing light to a subject, and a light emitting circuit 27 for driving the light emitting unit 26
And a dimming circuit 28 to which light from the light receiving element 24 is input and emits predetermined light.

The light control circuit 28 uses a built-in light emission threshold value LS1 for determining brightness as a reference value for comparison, and
The light emission from the light emitting unit 26 is started when the light emission threshold value LS1 exceeds the light amount threshold value LS1 compared with the light amount input from the light source. The light emission time is controlled by the light emission stop signal from the control unit 22, and the light emission in the light emission unit 26 is performed. Is stopped.

[0010] In addition, there is a communication terminal 29,
The communication terminal 29 is a terminal for connection with an external flash device. The communication terminal 29 is connected to the control unit 22 via a communication line or the like, and is used for controlling flash of the external flash device.

Further, the control section 22 is constituted by a microprocessor or the like. The control section 22 receives an image signal from the image signal processing circuit 14 and stores the image signal in a predetermined area LA1 of the memory 30 in which a program required for calculation is stored. A predetermined image processing operation is executed by using the color temperature information CT1 and the photographing information PI input from the operation unit 21 and the like, and is output to the image signal processing circuit 14 to perform image correction and to perform the image correction via the signal processing circuit 16. To display an appropriate image on the liquid crystal display 18.

In addition, the control unit 22 controls the signal processing circuit 1
For example, control of compression operation, communication control with an external flash device, and control of recording / reproducing of data to / from the memory card 20 at 6 are performed.

[0013]

In the above-mentioned conventional digital camera, image processing is performed by performing automatic light control using only the digital camera itself based on a fixed color temperature.
When attaching an external flash device to this,
Flash is performed in a form that matches the color temperature of the digital camera itself.

However, since the color temperature varies between the flash devices by about ± 500 ° K., it is difficult to obtain a clear image by simply mounting the conventional flash device as it is.

In a video camera recorder or the like, the color temperature is usually adjusted to 3600 ° K indoors.
Image processing is performed at 6000 ° K. Therefore, there is a problem that one flash device cannot be used commonly for a digital camera and a video camera recorder.

[0016]

According to the present invention, there is provided a flash device for solving the above-mentioned problems, which comprises a light-receiving unit for receiving reflected light from a subject and performing a flash on the subject from a light-emitting unit. A communication means for transmitting a color temperature specific to the flash to the camera via a communication line as color temperature information to obtain light amount information from the camera side; and a light emission amount threshold value using the light amount information. Control means for setting the light emission time of the flash and controlling the light emission time of the flash, and dimming means for controlling the flash from the light emitting unit based on the light emission threshold based on the amount of reflected light received by the light receiving element. It was made.

According to the present invention, there is provided a camera for shooting an object using an external flash device as a configuration of a camera corresponding to the flash device for solving the above-mentioned problem. A communication unit that obtains a color temperature specific to the flash of the flash device as color temperature information; determines light amount information of the flash using the set photographing information and the color temperature information; and transmits the light amount information to the flash device. And control means for performing the control.

Furthermore, the present invention provides a flash device for solving the above problems and an imaging device including a camera corresponding to the flash device, which includes a camera for photographing a subject, and a device for receiving reflected light from the subject. A flash device that emits light to the subject and an imaging device that connects these devices via a communication line to transmit data, wherein the camera sets a color temperature specific to a flash of the flash device through the communication line. Communication means for obtaining temperature information; andcontrol means for determining light amount information of a flash using the set photographing information and the color temperature information and transmitting the light amount information to the flash device. Communication means for obtaining the light amount information from the camera side via the communication line; and setting a light emission amount threshold value using the light amount information to emit the flash light. And control means for controlling between, in which so as to and a light control means for controlling the flash of the light emitting unit as a base of the light-emitting amount faction value based on the reflected amount of light received by the light receiving element.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an imaging apparatus according to the present invention will be described below with reference to FIG. FIG. 1 is a perspective view schematically showing one embodiment of the present invention. In addition,
To facilitate understanding, the same parts as those of the conventional digital camera are denoted by the same reference numerals and described.

As shown in FIG. 1, the image pickup device 31 comprises a digital camera 32 and a flash device 33. Of these, the structure of the digital camera 32 is as follows.

At the center of the front of the body, there is provided an imaging lens 11 for taking in the reflected light from the subject, and at the obliquely upper part thereof, a light receiving element 2 for receiving the reflected light from the subject.
4 and a light emitting unit 26 for flashing in accordance with the amount of light received by the light receiving element, and the light receiving element 24 and the light emitting unit 26 constitute a part of a built-in flash.

A shoe 32A is provided on the upper part of the digital camera 32. A leg 33A of an external flash device 33 is mounted on the shoe 32A. A communication terminal 29 provided on the side of the digital camera 32 is connected to a flash. A communication line 4 between a communication terminal 48 provided in the device 33;
9 to transmit a signal related to the flash.

A light-receiving element 42 and a light-emitting unit 42 are provided on the front of the flash device 33. These light-receiving and light-emitting elements can function for a longer distance to the subject than the built-in flash. .

FIG. 2 is a block diagram showing the configuration of the image pickup apparatus shown in FIG. 1. The light incident from the image pickup lens 11 shown in FIG. Is incident on.

The charge-coupled device 12 converts incident light incident on the photodiodes arranged in an array into an electric signal having an intensity corresponding to its brightness, and outputs this as an electric signal. This electric signal is converted into a digital signal by the analog / digital converter 13 and output to the image signal processing circuit 34.

The image signal processing circuit 34 has an analog
The digital signal output from the digital converter 13 is converted into an image signal, and the converted digital image signal is output to the signal processing circuit 35.

The signal processing circuit 35 compresses the digital signal in a compression format such as the JPEG system, and displays an image of the subject on the liquid crystal display 18 via the LCD drive circuit 17.

The digital signal from the image signal processing circuit 34 is subjected to necessary processing such as compression in the signal processing circuit 35, and after displaying the image of the subject on the liquid crystal display 18, the digital signal can be exchanged through the connector 19. The data is written and recorded on the memory card 36.

On the other hand, the image data stored in the memory card 36 is read out via the connector 19,
The image is displayed on the liquid crystal display 18 via the signal processing circuit 35 and the LCD drive circuit 17.

The memory card 36 may be a rewritable storage element, for example, any type of medium such as an IC memory, a magnetic memory, or a tape. The mechanism of the memory card 36 may be exchangeable or fixed. It may be of the formula.

In the operation unit 21, not only the shutter operation but also the operation of setting the aperture value, setting the distance to the subject, setting the shutter speed, and the like, and selecting the photographing conditions by the selection operation on the menu screen for selecting various camera functions. Configuration,
Selection and the like are performed, and the photographing information PI obtained by the setting and selection is transmitted to the control unit 37 functioning as control means.

The digital camera 32 has a built-in flash unit 38. The built-in flash unit 38 receives light reflected from a subject and converts the light into an electric signal. A / D converter 25 for converting to a digital signal, a light emitting unit 26 for flashing light to a subject, a light emitting circuit 27 for driving this light emitting unit 26, and a predetermined light emission when light from light receiving element 24 is input. And a dimming circuit 39 for performing the following.

The light control circuit 39 uses the built-in light emission amount threshold value LS2 for determining brightness as a reference value for comparison, and
The light emission unit 26 starts the light emission from the light emission unit 26 when the light emission amount threshold value LS2 is exceeded, and the light emission time is controlled by the light emission stop signal from the control unit 37 to emit light in the light emission unit 26. To stop.

In addition, there is a communication terminal 29,
The communication terminal 29 is a terminal for connection with an external flash device. The communication terminal 29 is connected to the control unit 37 by a communication line or the like, and is used for controlling flash of the external flash device 33.

Further, the control section 37 is constituted by a microprocessor or the like, takes in the image signal from the image signal processing circuit 34, and stores the image signal in a predetermined area LA2 of the memory 40 in which a program required for the operation is stored. A predetermined image processing operation is performed using the color temperature information CT2 and the photographing information PI input from the operation unit 21 and the like, and is output to the image signal processing circuit 34 to perform image correction to perform liquid crystal display 18 To display an appropriate image.

In addition, the control unit 37 controls the signal processing circuit 3
For example, control of the compression operation, communication control with the flash device 33, and control of recording / reproducing of data to / from the memory card 36 are performed. Although not shown, the power supply of the digital camera 32 can be driven by a battery of the video camera or an AA battery.

Next, the configuration of the flash device 33 is as follows. The memory 41 is, for example, an electrically rewritable nonvolatile memory such as an EEPROM (Electric
cally Erasable Programmab
le Read-Only Memory), and a flash memory 3 is stored in a predetermined memory area in the read-only memory.
3 stores the unique color temperature information CT2.

An analog electric signal based on the reflected light from the subject detected by the light receiving element 42 is converted into a digital signal by an A / D converter 43 and output to a dimming circuit 44. The signals are integrated and calculated as a light amount signal.

On the other hand, from the control unit 45, a light emission amount threshold value LS3, which is a threshold value serving as a reference for determining the brightness of the flash.
Is output, and when the light amount signal input from the light receiving element 42 reaches this light emission amount threshold value LS3, the light emitting circuit 4
The light-emitting unit 47 emits light through the light source 6 and flashes on the subject.
This is executed by the control signal DT related to the photographing information PI from. Further, the control unit 45 sends a timing signal for controlling the timing of digital conversion in the A / D converter 43, and controls the timing of digital conversion.

The flash device 33 is provided with a communication terminal 48, which is connected to the digital camera 3
2 is connected to the communication terminal 29 via a communication line 49, and is also connected to the control unit 45.

In the above configuration, first, when the flash device 33 is connected to the communication terminal 29 of the digital camera 32 via the communication line 49, the control unit 45 of the flash device 33 detects this connection and The color temperature information CT2 unique to the flash device 33 contained in the flash memory 33 is read.

Since the read color temperature information CT2 is transmitted to the digital camera 32 via the communication line 49, the control unit 37 stores the read color temperature information CT2 in the predetermined area LA1 of the memory 40 using the color temperature information CT2. The content of the color temperature information CT1 unique to the digital camera 32 is temporarily rewritten.

Further, the control unit 37 calculates optimal flash light amount information QI using photographing information PI such as the distance from the operation unit 21 to the subject and color temperature information CT2 stored in the memory 40. The calculation result is transmitted to the image signal processing circuit 34, subjected to image processing, displayed on the liquid crystal display 18, and sent to the control unit 45 of the flash device 33 via the communication line 49.

As this calculation, for example, the photographing information PI
Taking the shooting distance as an example, if the shooting distance is set to be long, the calculation for increasing the light amount of the flash is executed, and if the shooting distance is set to be short, the calculation for reducing the light amount is executed.

The control unit 45 controls the light emission of the light emitting unit 47 by setting the light emission threshold value LS3 using the light amount information QI. The light amount information QI is updated to correspond to the photographing information PI changed by the operation unit 21 by a communication check between the control unit 37 and the control unit 45 performed twice, for example, once every 30 seconds. You.

In this manner, even if the color temperature unique to the digital camera 32 and the color temperature unique to the flash device 33 are different, information can be exchanged between them via a communication line. Thus, automatic light control can be performed in a form in which the dependence on the model is removed.

Since these can be applied to a video camera recorder in the same manner as the digital camera 32, the flash device 33 can be used commonly for both a video camera recorder and a digital still camera, and Dimming can be controlled.

Since the digital camera 32 has a built-in flash unit 38, the built-in flash unit 38
Is set by the light emission threshold value LS2. However, in the case of the built-in flash, the reach of the flash is considerably shorter than in the case where the flash device 33 is used.

The control unit 37 also determines the light emission threshold value LS2
And transmits it to the control unit 45 via the communication line 49.
The control unit 45 sets the light emission threshold value LS3 as the light emission threshold value LS2 so that the brightness of the built-in flash and the brightness of the external flash device 33 can be made the same.

[0050]

As described above, according to the external flash device according to the present invention, the communication means for obtaining the light amount information on the camera side via the communication line, and the color temperature specific to the own flash are used. A color temperature storage means for storing as color temperature information is provided, so that the camera can be used in common for digital still cameras or video camera recorders having different color temperatures for automatic light control. In addition to enabling flash photography with correct color temperature, versatility is improved, and a convenient tool for the user can be provided.

According to the digital camera of the present invention, there is provided communication means for obtaining, as color temperature information, a color temperature specific to a flash of an external flash device via a communication line;
Control means for determining the light amount information of the flash using the set photographing information and the color temperature information and sending out the light amount information to the communication line is provided. Even if there is variation, it is possible to perform image processing that matches this flash device and flash the subject, and it is possible to capture a beautiful image.

Further, according to the imaging apparatus of the present invention,
Since the color temperature information unique to the flash can be shared between the flash device and the digital camera, the combination of the flash device and the digital camera can be freely selected, and these efficient operations can be performed. Possible benefits arise.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an embodiment of an imaging apparatus according to the present invention.

FIG. 2 is a block diagram showing an imaging device according to the embodiment.

FIG. 3 is a block diagram illustrating a configuration of a conventional digital camera.

[Explanation of symbols]

Reference Signs List 10: digital camera, 11: imaging lens, 12: charge-coupled device, 13: analog / digital converter, 14: image signal processing circuit, 16; signal processing circuit, 17: LCD drive circuit, 18; liquid crystal display, 20 Memory card, 2
1; operation unit, 22; control unit, 23; built-in flash unit,
24; light receiving element, 26; light emitting unit, 27; light emitting circuit, 28; dimming circuit, 29; communication terminal, 30;
31; an imaging device; 32; a digital camera; 33; a flash device; 34; an image processing circuit;
36; memory card, 37; control unit, 38; built-in flash unit, 39; light control circuit, 40; memory, 41; memory, 42; light receiving element, 44; light control circuit, 45;
46; light emitting circuit; 47; light emitting unit; 48; communication terminal; 49; communication line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H002 CD05 CD09 GA54 GA75 JA07 JA08 2H053 AA00 AD08 AD14 BA72 BA82 CA22 CA41 DA03 5C022 AA13 AB15 5C065 AA01 AA03 BB01 BB41 CC01 CC08 DD02 GG18 GG27 HH01

Claims (13)

[Claims] 1. A flash device for receiving a reflected light from a subject with a light receiving element and performing a flash on the subject from a light emitting unit, wherein a color temperature specific to the flash of the subject is communicated via a communication line. Communication means for sending light amount information from the camera side to the camera side, control means for setting a light emission amount threshold value using the light amount information and controlling the flash emission time, and reflection received by the light receiving element A flash control device for controlling a flash from the light emitting unit based on the light amount threshold based on a light amount. 2. The flash device according to claim 1, wherein the light amount information includes at least photographing information set on the camera side. 3. The flash device according to claim 1, wherein the light emission threshold value is set in accordance with the light emission threshold value on the camera side. 4. A camera for photographing a subject using an external flash device, wherein said communication means obtains a color temperature specific to a flash of said flash device as color temperature information via a communication line. A camera comprising: control means for determining light amount information of a flash using photographing information and the color temperature information and transmitting the light amount information to the flash device. 5. The camera according to claim 4, wherein the shooting information includes all or at least one of distance data to a subject, an aperture value, and a shutter speed. 6. The camera according to claim 4, wherein the camera includes image processing means for performing image processing of a subject based on the light amount information. 7. The camera according to claim 4, wherein the camera includes at least a video camera recorder and a digital still camera. 8. A camera for photographing a subject, a flash device for receiving reflected light from the subject and emitting light to the subject, and an imaging device for connecting the devices via a communication line and transmitting data, A communication unit that obtains, as color temperature information, a color temperature specific to the flash of the flash device via the communication line; and determines light amount information of the flash using the set shooting information and the color temperature information. Control means for transmitting the light amount information to the flash device, wherein the flash device emits light using the light amount information from a communication unit for obtaining the light amount information from the camera via the communication line. Control means for setting a threshold value and controlling the light emission time of the flash; and the light emitting unit based on the light emission threshold value based on the amount of reflected light received by the light receiving element. An image pickup apparatus comprising: a light control unit that controls a flash of the camera. 9. The imaging apparatus according to claim 8, wherein the light amount information includes at least shooting information set on the camera side. 10. The imaging device according to claim 8, wherein the color temperature information is set based on the color temperature information of the built-in flash device on the camera side, when the color temperature information is available. 11. The imaging apparatus according to claim 8, wherein the shooting information includes all or at least one of distance data to a subject, an aperture value, and a shutter speed. 12. The imaging apparatus according to claim 8, wherein the camera includes an image processing unit that performs image processing of a subject based on the light amount information. 13. The imaging apparatus according to claim 8, wherein the camera includes at least a video camera recorder and a digital still camera.