JP2003179808A - Image pickup device and portable electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device in a simplified configuration to control the exposure at strobe photographing in response to the distance up to an object. <P>SOLUTION: When a control section 1 discriminates that an image is darker than a prescribed value 1 on the basis of an output of a CdS14, the control section 1 stores a photometric output from the CdS14 while an LED 9 is in a non-emitting state and allows the LED 9 to emit light in a prescribed luminous quantity. The control section 1 stores the photometric output of the CdS14 at that time and obtains a difference between the two photometric outputs. When the obtained output difference is a prescribed value 2 or below, the control section 1 allows the LED 9 to emit light in a luminous quantity 1 (e.g. maximum luminous quantity), when the obtained output difference is greater than the prescribed value 2 or is equal to or less than a prescribed value 3 (prescribed value 2 < prescribed value 3), the control section 1 allows the LED 9 to emit a light with a luminous quantity 2 (luminous quantity 1 > luminous quantity 2), and when the obtained output difference is greater than the prescribed value 3, the control section 1 allows the LED 9 to emit light in a luminous quantity 3 (luminous quantity 2 > luminous quantity 3) to photograph a still picture. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile electronic device such as an imaging device and a mobile phone, and more particularly to an imaging device capable of illuminating a subject and a mobile electronic device such as a mobile phone.

[0002]

2. Description of the Related Art Conventionally, in an image pickup device having a strobe,
There is a device that determines whether or not a strobe is to be emitted during still image shooting based on the output of a photometric element such as CdS for exposure amount control. Further, for controlling the exposure amount during strobe shooting according to the subject distance, for example, Some have a dedicated range finder such as an active type range finder or a passive type range finder and use the output thereof.

Further, for example, in a portable electronic device such as a mobile phone equipped with an image pickup device, since the subject distance is not obtained, the exposure amount control such as controlling the strobe light amount at the time of strobe light emission is not performed.

[0004]

In the above image pickup device,
Since a dedicated distance measuring device is used to control the exposure amount at the time of flash photography according to the subject distance, there is a problem that the configuration becomes large.

Further, a portable electronic device such as a mobile phone equipped with an image pickup device does not obtain information according to the subject distance, and therefore the strobe light amount cannot be controlled. There was a problem that it became too large and turned into a whitish photo (image).

An object of the present invention is to simplify the structure of an image pickup apparatus which controls the exposure amount at the time of stroboscopic photography according to the subject distance. Another object of the present invention is to provide a portable electronic device equipped with an image pickup device capable of controlling an exposure amount during stroboscopic photography.

[0007]

SUMMARY OF THE INVENTION A first invention is a light emitting section for illuminating an object, a release switch for instructing still image shooting, a photometric section for detecting the brightness of the object, and an output of the photometric section. Based on the output of the photometry unit when the light emitting unit emits light and the output of the photometry unit when the light emitting unit does not emit light It is an imaging device including a control unit that controls the light amount of the light emitting unit at the time of image capturing. With such a configuration, it is possible to control the exposure amount at the time of stroboscopic photography according to the subject distance based on the output of the photometry unit for controlling the exposure amount at the time of still image photography. In other words, the light amount of the light emitting unit during still image shooting is controlled based on the information according to the subject distance obtained based on the output of the light measuring unit when the light emitting unit emits light and the output of the light measuring unit when the light emitting unit does not emit light. It will be possible. Therefore, the structure can be simplified.

According to a second aspect of the present invention, the control unit controls the still image based on the difference between the output of the photometric unit when the light emitting unit emits light and the output of the light emitting unit when the light emitting unit does not emit light. The light amount of the light emitting unit is controlled at the time of shooting. According to such a configuration, in addition to the above effect, the object distance is obtained based on the difference between the output of the photometric unit when the light emitting unit emits light and the output of the light emitting unit when the light emitting unit does not emit light. It is possible to control the light amount of the light emitting unit at the time of still image shooting based on the information.

According to a third aspect of the present invention, the control unit reduces the light amount of the light emitting unit when the still image is captured, as the difference between the outputs increases. According to such a configuration, in addition to the above effects, the distance to the subject and the reflectance to the subject increase depending on the characteristic that the output difference increases as the subject distance decreases and the reflectance of the subject increases. It is possible to control the light amount of the light emitting portion based on the light emitting portion.

According to a fourth aspect of the present invention, the control unit determines whether or not the light emitting unit needs to be driven when the still image is captured, based on the output of the photometric unit when the light emitting unit is not emitting light. . According to such a configuration, in addition to the above effects, the output of the photometric unit when the light emitting unit is not emitting light is used both for controlling the light amount of the light emitting unit and for determining whether or not the light emitting unit is driven. Therefore, the processing can be simplified.

According to a fifth aspect of the present invention, a light emitting unit for illuminating a subject, a release switch for instructing still image shooting, a photometric unit for detecting the brightness of the subject, and the photometric unit for emitting light from the light emitting unit. And a control unit that generates an output according to the distance to the subject based on the output of the above and the output of the photometric unit when the light emitting unit does not emit light. With such a configuration, an output according to the subject distance is generated based on the output of the photometry unit when the light emitting unit emits light and the output of the photometry unit when the light emitting unit does not emit light, so that a still image shooting is performed. An output according to the subject distance can be generated based on the output of the photometry unit for controlling the exposure amount at the time.

According to a sixth aspect of the invention, the light emitting portion is an LED. According to such a configuration, in addition to the above effects,
The light emitting unit can be downsized and noise can be reduced.

A seventh aspect of the present invention is a portable electronic device integrally equipped with the above-mentioned image pickup device. With such a configuration, it is possible to provide a portable electronic device that has the above-described effect and that includes an imaging device that can control the exposure amount during flash photography.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to an embodiment shown in the drawings. In this example, an example in which an imaging device is provided in a mobile phone as a mobile electronic device will be described.

FIG. 1 is a functional block diagram showing the electrical configuration of a mobile phone. In the figure, a control unit 1 as a light amount control unit and an exposure control unit is mainly composed of a microcomputer including a CPU and the like, and a wireless communication unit 2, an audio input / output unit 3, and a C as an imaging unit.
CD camera 4, keypad 5, color L as display
CD6, external device connection interface 7, memory 8,
L as a light emitting unit that emits light for illuminating a subject
A drive circuit 10 for driving the ED 9, a light emission mode setting unit 11 for setting a light emission mode of the LED 9, a release switch 12 for outputting a release signal for instructing the start of still image shooting, and an operation mode setting unit also serving as a power switch. 13 and a CdS 14 as a photometric unit are connected. An antenna 15 is connected to the wireless communication unit 2,
A microphone 16 and a receiver 17 are connected to the voice input / output unit 3.

Upon receiving the transmitted voice, the microphone 16 converts the input transmitted voice from an audio signal into an electric signal to generate a transmitted signal, and outputs the transmitted signal to the voice input / output unit 3. When the voice-transmitting signal is given from the microphone 16, the voice input / output unit 3 performs an amplification process and an A / D for the voice-transmitting signal.
The conversion process is executed, and the wireless communication unit 2 is operated through the control unit 1.
Output the transmission signal to. When the transmission signal is given from the voice input / output unit 3 through the control unit 1, the wireless communication unit 2 performs baseband processing, wireless processing, and the like on the transmission signal, and the antenna 15 widebands the communication frequency band. It is radiated as a transmission radio wave of (for example, a communication frequency band assigned to wireless communication using a code division multiple access (CDMA) system).

When the antenna 15 captures a radio wave in the above-mentioned wideband communication frequency band as a received radio wave, the radio communication unit 2 executes radio processing and baseband processing on the captured radio wave to generate a reception signal. Then, the received signal is output to the voice input / output unit 3 through the control unit 1. The voice input / output unit 3, when receiving the reception signal from the wireless communication unit 2 through the control unit 1, executes D / A conversion processing and amplification processing on the received reception signal, and outputs the reception signal to the receiver 17. . When receiving the reception signal from the voice input / output unit 3, the receiver 17 converts the reception signal from an electric signal into a voice signal to generate a reception voice, and outputs the generated reception voice.

The CCD camera 4 captures a subject image, generates electrical image information (so-called photoelectric conversion) according to the captured image, and outputs it to the control unit 1.

The keypad 5 includes a call start key, a redial key, a call end key, numeric keys "0" to "9", *
(Asterisk) key, # (pound) key and F
Various keys such as a (function) key are arranged and configured. When any key is operated, a key operation signal corresponding to the key operation is output to the control unit 1.
When a key operation signal is given from the keypad 5, the control unit 1 decodes the key operation signal and executes a process according to the decoded result.

When a display signal is given from the control section 1, the LCD 6 displays the display information according to the given display signal. The external device 18, like the CCD camera 4,
The external device connection interface 7 is a digital still camera or the like having a function of capturing image information, and the external device connection interface 7 inputs image information captured by the external device 18 on condition that the mobile phone 1 and the external device 18 are connected. Then, the input image information is output to the control unit 1. The display unit is not limited to the color LCD, and an organic EL display or the like can be appropriately changed.

The memory 8 forming a control means in cooperation with the control unit 1 is a flash memory, a ROM, a RAM and a V memory.
A storage element such as a RAM (video RAM) is provided, and an execution program is stored in the ROM. The control unit 1 reads out the execution program and executes processing to execute various operations described later. The flash memory in the memory 8 stores the image information input from the CCD camera 4 and the image information input from the external device connection interface 7 when the release switch 12 operates. V in memory 8
The RAM stores image information input from the CCD camera 4 displayed on the LCD 6 and image information input from the external device connection interface 7. The RAM in the memory 8 is used for various processes.

The LED 9 as a light emitting portion is an LED for illuminating a subject, and in this example, a white LED for irradiating white light is used. As the white LED, for example, a high brightness white LED (model number: NSPW51 manufactured by Nichia Corporation)
0BS) or the like is used. Although FIG. 1 shows an example in which two LEDs 9 are adopted, the number of LEDs can be changed appropriately. For example, the amount of light required for illumination differs depending on the detection characteristics of the CCD (image sensor) used in the CCD camera 4. Therefore, when a large amount of light is required for illumination, the number of LEDs 9 is increased to increase the amount of light. When a large amount of light is not needed for illumination, it is possible to change it to a single LED. In addition, as a supplement to the LED, in recent years, L which emits high-luminance light with a driving voltage of about several tens of volts is used.
Commercialization of EDs has been achieved, and the products that have been illuminated by light bulbs and the like are being developed and are being put to practical use. For example, an LED has been adopted and put into practical use as a light emitting unit of a pen-type light or an illumination device attached to a head by an operator. The light emitting unit is not limited to the white LED, and can be changed as appropriate, for example, an LED that emits light of a desired color,
A light emitting portion that emits white light by combining red, green, and blue LEDs, or a lamp such as a light bulb may be used, but when the LED is used, the size can be reduced. Also, when a white LED is used as the light emitting unit, since one LED can emit white light, red,
The size can be reduced and the number of parts can be reduced as compared with the case of combining green and blue LEDs to emit white light.

The drive circuit 10 outputs L output from the control unit 1.
The LED 9 is driven based on a light amount control signal (output according to the subject distance) that indicates the amount of light emitted from the ED 9. The light amount control signal output from the control unit 1 may be information designating the light emission amount of the white LED 9, and therefore the red LED and the green LE are included.
As in the case of controlling the light quantity of the light emitting section that emits white light using D and the blue LED, control considering white balance is not necessary, and the light quantity control signal can be simplified.

The light emission mode setting unit 11 is for setting the light emission mode of the LED 9. In this example, the light emission mode of the LED 9 and the automatic light emission mode for automatically controlling the light emission and the light emission amount of the LED 9 according to the subject brightness are set. A prohibited light emission mode can be set, and for example, the automatic light emission mode and the light emission prohibited mode are switched each time the operation is performed once. The control unit 1 controls the light emission of the LED 9 according to the mode set by the light emission mode setting unit 11 and the like, and causes the LCD 6 to display the set mode.

The operation mode setting unit 13 is in a state in which the power is turned off (OFF mode), a state in which the telephone can be transmitted and received (telephone mode), a state in which the image information stored in the memory 8 is displayed (view mode), and a camera photographing. Possible state (shooting mode) and LED (light emitting unit) 9 with a predetermined light amount (brightness)
It is possible to set the state of continuously emitting light (light mode) selectively. For example, the mode switches between off mode, telephone mode, view mode, shooting mode, and light mode each time it is operated. There is. The control unit 1 controls various operations according to the mode set by the operation mode setting unit 13 and causes the LCD 6 to display the set mode. It is possible to receive an incoming call in a mode other than the off mode.

The CdS 14 generates a photometric output according to the brightness of the subject. The photometric unit is not limited to CdS and can be changed as appropriate, and for example, a photodiode or the like may be used. The control unit 1 controls the exposure when the CCD camera 4 captures a still image based on the photometric output output from the CdS 14. Specifically, the control unit 1 controls the accumulation time of the CCD 402, which will be described later, at the time of capturing a still image based on the photometric output. As an example of how to control the accumulation time, CdS
There is a method in which the accumulation time is shortened as the metering output of indicates a brighter state. In the case of a configuration in which a diaphragm is provided between the CCD 402 and a photographic lens 401, which will be described later, the control unit 1 controls the opening amount (that is, the exposure amount) of the diaphragm based on the photometric output to perform the exposure control. Good. Further, the control unit 1 may control both the opening amount of the diaphragm and the accumulation time of the CCD 402 based on the photometric output.

FIG. 2 is a block diagram showing the CCD camera 4, the control unit 1 and the like. In the figure, the taking lens 40
The CCD 402, which is an image pickup device in which an optical image of an object is formed on the light receiving surface by 1, is a solid-state image pickup device that performs photoelectric conversion to output an analog signal corresponding to the optical image and transfers charges in an array. Then, it is used as a so-called solid-state image sensor that converts two-dimensional optical information into a time series (serial string) electric signal.

A supplementary explanation of the CCD 402 is that the CCD
Reference numeral 402 denotes a photoelectric conversion unit in which a large number of photoelectric conversion elements are arranged in an array, a charge accumulation unit that accumulates output charges of the photoelectric conversion elements, and a charge reading unit that reads out the charges accumulated in the charge accumulation unit by a predetermined method. Each of the photoelectric conversion elements is a pixel. The CCD 402 in this example is a color CCD. In general, the pixel information of the CCD does not have color information. Therefore, the color CCD is equipped with a color filter (a primary color filter using the three primary colors of light or a complementary color filter using the three primary colors of light) on the front surface.

The horizontal / vertical driver 403 and the timing generator (TG) 404 generate drive signals necessary for reading the CCD 402. Specifically, drive signals for transferring (reading) pixel information in units of rows while sequentially designating each column of the CCD 402, that is, horizontal and vertical drive signals for serially reading pixel information are generated.

The sample hold circuit 405 is the CCD 40.
The time-series signal (analog signal at this stage) read out from No. 2 is sampled at a frequency suitable for the resolution of the CCD 402. Note that automatic gain adjustment (AGC) may be performed after sampling.

The analog-digital converter 406 converts the sampled signal into a digital signal.

The color process circuit 407 outputs the luminance / image as image information from the output of the analog / digital converter 406.
A color difference multiplex signal (hereinafter referred to as "YUV signal") is generated. The signal format of the YUV signal is
It is composed of three fixed-length blocks called "components" that include a luminance signal and two color-difference signals independently, and the ratio of the length (the number of bits) of each component is called the component ratio.

The DMA controller 408 performs data transfer between the color process circuit 407 and the DRAM 410 (more precisely, the DRAM interface 409) without the intervention of the control unit 1, and so-called direct memory transfer (DMA: DIRECT MEMORY). ACC
ESS).

The DRAM interface 409 is a DR
It serves as a signal interface between the AM 410 and the DMA controller 408 and a signal interface between the DRAM 410 and the control unit 1.

FIG. 3 is a view showing the outer appearance of the mobile phone of this example. In FIG. 3, the same components as those in FIG. 1 are designated by the same reference numerals. The taking lens 401, the CCD 402, and the LED 9 are integrally formed and are rotatable about the shaft 500. Therefore, it becomes possible to photograph the user himself / herself by using the CCD camera 4. Further, since both of the image pickup lens and the light emitting unit can be moved simultaneously while maintaining the positional relationship, the operability is improved as compared with the case where the image pickup lens and the light emitting unit are readjusted to be readjusted. In this way, since the mobile phone is integrally equipped with the image pickup device using the LED as the light emitting unit, noise can be reduced and downsizing can be achieved as compared with the case where the xenon tube is used as the light emitting unit as in the conventional case. The degree of freedom in design is improved. Further, since the white LED is used as the light emitting portion, the configuration can be simplified and the number of parts can be reduced as compared with, for example, a device that emits white light using a red LED, a green LED, and a blue LED.

Next, the operation will be described.

When the telephone mode is set by the operation mode setting unit 13, the control unit 1 controls the wireless communication unit 2, the voice input / output unit 3,
The mobile phone function using the antenna 15, the microphone 16, the receiver 17, etc. is made operable, and the user can use it as a normal mobile phone.

When the view mode is set by the operation mode setting unit 13, the control unit 1 gives a display signal according to the image information stored in the memory 8 to the LCD 6 and displays an image according to the image information on the LCD 6. Let

When the operation mode setting unit 13 sets the light mode, the control unit 1 causes the LED 9 to emit a predetermined amount of light (brightness). Therefore, when the light mode is set, the mobile phone can be used as a lighting device.
Also, as will be described later, an LED (light emitting unit) used for shooting
Since 9 is also used for illumination, the structure can be simplified, and since the LED is used as the light emitting portion, further downsizing of the structure can be realized. In the light mode, the light amount of the LED 9 may be adjustable by operating the keypad 5.

When the shooting mode is set by the operation mode setting unit, the control unit 1 operates the CCD camera 4 to capture image information corresponding to the subject image output by the CCD camera 4 while shooting and updating in real time. , VR of memory 8
It is sent to the LCD 6 via AM or the like and displayed on the LCD 6. In this state, the user looks at the LCD 6 to determine the composition. At this time, the control unit 1 confirms the setting in the light emission mode setting unit 11.

The operation when the automatic light emission mode is set by the light emission mode setting unit 11 will be described with reference to FIG.

When the release switch 12 is operated with the automatic light emission mode set (step 4a), the control section 1 displays an image on the LCD 6 based on the photometric output output from the CdS 14 when the release switch 12 is operated. Is determined to be brighter than the predetermined value 1 (provided that the predetermined value 1 is stored in the memory 8 in advance) (step 4b), the still image is photographed without emitting the LED 9 (step 4c). Specifically, the control unit 1 uses the CdS14
The storage time of the CCD 402 is determined based on the photometric output output from the CCD 402, and the charge corresponding to the subject image is accumulated in the CCD 402 during the determined storage time to capture the subject image. When the determined accumulation time elapses, the image information (YUV signal) corresponding to the captured subject image is D
It is stored in the RAM 410. The information used when the control unit 1 determines the accumulation time is not limited to the photometric output output from the CdS 14, and a luminance signal included in the image information output from the CCD camera 4 may be used.

The control unit 1 controls the Y stored in the DRAM 410.
The UV signal is fixed, the fixed YUV signal is taken in through the DRAM interface 409, and the display of the LCD 6 is fixed to an image corresponding to the fixed YUV signal. The control unit 1 stores the captured YUV signal in the flash memory of the memory 8 after, for example, JPEG encoding.

When the control unit 1 determines that the image displayed on the LCD 6 is darker than the predetermined value 1 based on the photometric output (step 4b), the control unit 1 determines that the surroundings are dark and a strobe is necessary, and the photometry is performed. Output, ie LED (light emitting part)
The photometric output (hereinafter referred to as “photometric output 1”) output by the CdS 14 when the release switch 12 is operated while 9 is not emitting light is stored in the RAM of the memory 8 (step 4d) and the LED 9 is set to a predetermined value. The light is emitted with the amount of light (step 4e).

The control unit 1 stores the photometric output (hereinafter referred to as "photometric output 2") output by the CdS 14 when the LED 9 is emitting a predetermined amount of light in the RAM of the memory 8 (step 4f).

When the storage of the photometric output 2 is completed, the control unit 1
Calculates the output difference between photometric output 1 and photometric output 2 (step 4g).

Here, supplementing the output difference obtained in step 4g, the fact that this output difference is large means L
LED compared to the amount of light received by CdS14 when ED9 is not emitting light
The amount of light emitted from CdS14 and reflected by the subject and received by CdS14 is large, and the small output difference means that the amount of light received by CdS14 when LED9 is not emitting and the amount of light emitted from LED9 and reflected by the subject are reflected. CdS1
This means that the difference in the amount of light received at 4 is small. C
The reflected light received by the dS 14 becomes smaller as the subject distance becomes farther, and becomes smaller as the subject reflectance becomes lower. Therefore, the magnitude of the output difference becomes information according to the subject distance and the subject reflectance. Become. That is, the shorter the subject distance, the larger the output difference, and the higher the subject reflectance, the larger the output difference.

When the calculated output difference is less than the predetermined value 2 (step 4h), the amount of light reflected from the LED 9 in step 4e by the subject is small, it is determined that the subject is far and the reflectance is low, and the drive circuit 10 is determined. To the LED 9 to output a light amount control signal for causing the LED 9 to emit light with a light amount of 1 (for example, the maximum light amount).
Light at a light intensity of 1 (for example, the maximum light intensity) (step 4
i). This light amount control signal becomes an output according to the subject distance and an output according to the reflectance of the subject.

The calculated output difference is larger than the predetermined value 2 and is a predetermined value 3 (provided that predetermined value 2 <predetermined value 3 <predetermined value 1 and these values are stored in the memory 8 in advance).
In the following cases (step 4j), it is determined that the subject has a medium distance and a medium reflectance, and the drive circuit 10 outputs a light amount control signal for causing the LED 9 to emit light with a light amount of 2 (where light amount 1> light amount 2). Then, the LED 9 is caused to emit light with a light amount of 2 (step 4k).

When the obtained output difference is larger than the predetermined value 3 (step 4j), it is judged that the subject is close and the reflectance is high, and the LED 9 is provided to the drive circuit 10 with the light amount 3 (however, light amount 2> light amount 3). Output a light intensity control signal to
The ED 9 is caused to emit light with a light amount of 3 (step 41).

When the operations of steps 4i, 4k and 4l are executed, the control section 1 carries out the above-mentioned still image photographing (step 4c). Specifically, the control unit 1 determines the storage time of the CCD 402 based on the photometric output output from the CdS 14, and the subject image is displayed on the CCD 402 during the determined storage time after the LED 9 starts emitting light as described above. A corresponding charge is accumulated and a subject image is captured. When the determined accumulation time has elapsed, the image information (YUV signal) corresponding to the captured subject image as described above is stored in the DRAM 410. It should be noted that the storage time of the CCD 402 may be fixed to a predetermined time when a still image is captured by the light emission of the LED 9, or may be changed based on the output of the CdS 14 or the output of the CCD 402. When the accumulation time of the CCD 402 is fixed to a predetermined time, for example, when a still image is photographed without the LED 9 emitting light, the CdS 14 outputs C
The exposure amount is controlled by changing the storage time of the CD402, and the LED
When shooting a still image accompanied by the light emission of 9, it is possible to control the exposure amount by changing the light amount of the LED 9 based on the output of the CdS 14.

The control unit 1 controls the Y stored in the DRAM 410.
The UV signal is fixed, the fixed YUV signal is taken in through the DRAM interface 409, and the display of the LCD 6 is fixed to an image corresponding to the fixed YUV signal. The control unit 1 stores the captured YUV signal in the flash memory of the memory 8 after, for example, JPEG encoding.

When the still image shooting is completed, the control unit 1 sets LE
D9 is turned off (step 4m) and the process returns to step 4a.

As a light quantity control method, when a plurality of LEDs are provided, the number of LEDs 9 to be turned on may be changed, or the drive current supplied to the same LED may be changed according to the light quantity. They may be controlled or they may be combined. In the case of a configuration in which the light amount of the light from the LED is controlled by changing the drive current supplied to the LED, it is possible to control the light amount with the same LED. In the case of a configuration in which the number of LEDs is plural and the light quantity of the light from the LEDs is controlled by changing the driving number of the LEDs, the light quantity control according to at least the number of LEDs becomes possible, and the magnitude of the light quantity is also the LED.
Can be larger than when singular.

Further, in the above, the light amount is controlled in three steps when the LED 9 is made to emit light, but the number of steps is not limited to three steps and may be less than three steps or more than three steps depending on the output difference of the photometric output. You may.

As described above, the subject distance and the reflection of the subject obtained based on the photometric output output from the photometric unit when the light emitting unit emits light and the photometric output output from the photometric unit when the light emitting unit does not emit light. It is possible to control the light amount of the light emitting unit at the time of still image shooting based on the information according to the rate. Further, it is possible to control the light amount of the light emitting unit at the time of still image shooting based on the information according to the subject brightness and the subject reflectance obtained based on the output difference between the two photometric outputs. Further, the shorter the subject distance and the higher the reflectance of the subject, the greater the difference in the above outputs. Therefore, if the light amount of the light emitting unit during still image shooting is controlled based on this output difference, the subject distance and the subject can be controlled. It is possible to control the light amount of the light emitting unit based on the reflectance of the light. In addition, the subject distance is determined based on the photometric output output from the photometry unit for controlling the exposure amount when the light emitting unit emits light and the photometric output output from the photometry unit for controlling the exposure amount when the light emitting unit does not emit light. , The information corresponding to the subject distance can be obtained by using the photometric output output by the photometry unit for exposure amount control.

Since the photometric output used to determine whether or not a strobe is necessary for still image shooting is also used to obtain information according to the subject distance and the reflectance of the subject,
The image information detected once can be applied to a plurality of processes.
Information corresponding to the subject distance and the reflectance of the subject may be obtained based on a photometric output that is different from the photometric output used to determine whether or not a strobe is required when capturing a still image. Further, when obtaining information according to the subject distance or the reflectance of the subject, in the above, the light emitting unit obtains the output of the light measuring unit when the light emitting unit does not emit light, but the light emitting unit obtains the output of the light measuring unit when emitting light. The order may be reversed. Further, in the above, the photometric output of CdS as the photometric unit is used as the information for determining whether or not the strobe is necessary when capturing a still image.
The control unit 1 may determine whether or not a strobe is required when capturing a still image based on the luminance signal included in the image information output from the CCD camera 4.

Further, since the LED is used as the light emitting section for irradiating the light for illuminating the object, the light emitting section can be miniaturized. Therefore, the degree of freedom in design is improved. Also,
Unlike the xenon tube, the LED can be easily controlled for lighting, so it can be used for other than conventional strobe light for dark shooting, such as illuminating the subject so that the user can check the composition when the surroundings are dark. Next, the usability of the user is expanded. Further, unlike the xenon tube, a driving voltage of several hundreds of volts is not required, so that noise caused by this high voltage can be reduced, and the design constraint due to noise can be reduced as compared with the conventional case.

Further, since the light emitting portion serves both as the light emitting portion for obtaining the subject distance information and the reflectance information of the subject and the so-called strobe light at the time of shooting a still image when the release switch is operated, the structure can be simplified.

If the light emission mode setting unit 11 sets the light emission prohibition mode when the operation mode setting unit is set to the photographing mode, the control unit 1 does not cause the LED 9 to emit light, and the control unit 1 stops as in step 4c described above. Take a picture.

Although a CCD is used as the image pickup unit in the above description, the present invention is not limited to this. For example, an image sensor such as a CMOS sensor may be used.

In the above description, an example in which a mobile phone as a mobile electronic device is equipped with an image pickup device has been shown, but the mobile electronic device is not limited to the mobile phone. For example, it may be a so-called notebook personal computer, an information portable terminal, or the like. When this image pickup device is integrated with a mobile electronic device that performs wireless communication, such as a mobile phone, a lens drive for distance measurement or a dedicated distance measurement device can be dispensed with, and a strobe light according to the subject distance or subject reflectance can be obtained. It becomes possible to control.

Further, in the above, the strobe light amount is controlled according to the output of the photometric unit when the light emitting unit emits light and the output of the photometric unit when the light emitting unit does not emit light. Since the information depends on the distance, for example, the taking lens 40
1 is provided with a drive means for driving the optical axis direction 1, and the drive means is driven according to the output difference output from the control section 1 to control the focusing of the taking lens 401 and the CCD 402. Good.

In the above, an example in which a so-called digital still camera using a CCD is adopted as an image pickup device is shown, but the image pickup device is not limited to this, and it may be used as a so-called silver salt camera for photographing a subject image on a silver salt film. Good.

Although the image pickup apparatus mounted on the portable electronic device has been described above, the image pickup apparatus is not limited to the image pickup apparatus mounted on the portable electronic device.

[0066]

According to the present invention, it is possible to control the exposure amount at the time of stroboscopic photography according to the object distance based on the output of the photometric unit for controlling the exposure amount at the time of still image photography. That is,
It is possible to control the light amount of the light emitting unit during still image shooting based on information according to the subject distance obtained based on the output of the light measuring unit when the light emitting unit emits light and the output of the light measuring unit when the light emitting unit does not emit light. Become.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing the CCD camera of FIG.

FIG. 3 is a front view showing the outer appearance of an embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of FIG.

[Explanation of symbols]

1 control unit 9 Light emitting part 12 Release switch 14 Metering unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoichi Nakano             Sei 1-1 Akanehama, Narashino City, Chiba Prefecture             Co-Precision Co., Ltd. (72) Inventor Hirofumi Okuyama             Sei 1-1 Akanehama, Narashino City, Chiba Prefecture             Co-Precision Co., Ltd. F-term (reference) 2H002 AB04 CD07 DB06 DB25                 2H053 AB03 AD06                 5C022 AA13 AB01 AB15 AC42

Claims (7)

[Claims] 1. A light emitting unit for illuminating a subject, a release switch for instructing still image shooting, a photometric unit for detecting the brightness of the subject, and an exposure amount for still image shooting based on the output of the photometric unit. Based on the exposure control unit that controls, the output of the photometry unit when the light emitting unit emits light, and the output of the photometry unit when the light emitting unit does not emit light, the light amount of the light emitting unit during the still image shooting is determined. An image pickup apparatus comprising: a control unit for controlling. 2. The control unit according to claim 1, wherein the control unit determines the stationary state based on a difference between an output of the photometry unit when the light emitting unit emits light and an output of the light emitting unit when the light emitting unit does not emit light. An image pickup device for controlling the light amount of the light emitting unit at the time of photographing an image. 3. The image pickup device according to claim 2, wherein the control unit reduces the light amount of the light emitting unit when the still image is captured, as the difference between the outputs increases. 4. The control unit according to claim 1, wherein the control unit needs to drive the light emitting unit at the time of capturing the still image based on the output of the photometric unit when the light emitting unit is not emitting light. An image pickup apparatus, which is for determining. 5. A light emitting unit for illuminating a subject, a release switch for instructing still image shooting, a photometric unit for detecting the brightness of the subject, and an exposure amount for still image shooting based on the output of the photometric unit. Generates an output according to the distance to the subject based on the exposure control unit that controls, the output of the photometry unit when the light emitting unit emits light, and the output of the photometry unit when the light emitting unit does not emit light An image pickup apparatus comprising: a control unit. 6. The image pickup device according to claim 1, wherein the light emitting unit is an LED. 7. A portable electronic device comprising the image pickup device according to claim 1 integrally.