JP4539901B2 - Digital camera with frame sequential flash - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital camera with a field-sequential light emission strobe, and more particularly to a digital camera with a field-sequential light emission strobe capable of obtaining a high-quality image.
[0002]
[Prior art]
Conventional digital cameras use color image sensors with color filters such as R, G, B (red, green, blue) or Mg, Cy, Ye (magenta, cyan, yellow) attached, and strobe light. As a photographer using a white light source such as a xenon tube.
[0003]
In recent years, strobe devices that use R, G, and B light emitting diodes (LEDs) as strobe light sources, change the color temperature of strobe light, and can emit strobe light with a slow shutter have been proposed (Japanese Patent Application Laid-Open No. 2002-2001). -116481).
[0004]
[Problems to be solved by the invention]
By the way, the luminance signal generated based on the R, G, B signals output from the color image sensor is R: G: B = 0.3: 0 so as to match the sensitivity characteristic with respect to the brightness of human eyes. .6: 0.1, the SN of B is poor, and there is a problem that noise in dark portions of B color increases when an image is printed based on captured image data.
[0005]
Further, since the color image sensor generates R, G, and B signals on a certain pixel by interpolating an insufficient color signal from surrounding pixels, the color image sensor is more than a monochrome image sensor having the same number of pixels. There is also a problem that the resolution is low. In order to solve this problem, some have three-plate type image pickup devices for R, G, and B. In this case, however, the number of image pickup devices, installation space, and the like increase.
[0006]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a digital camera with a field-sequential light-emission strobe that can obtain a high-quality color image using a monochrome image sensor without a color filter. And
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a digital camera with a field-sequential light emission strobe according to claim 1 includes a field-sequential light-emission strobe that emits light in a field-sequential manner in a wavelength range of R, G, and B, a monochrome imaging unit, Control means for performing imaging three times with one shutter release, and sequentially emits strobe light in a predetermined order in the wavelength ranges of R, G, and B from the surface sequential light emission strobe, and the R, G, and Control means for acquiring the R-, G-, and B-frame sequential image data from the imaging means by performing the imaging operation of the imaging means in synchronization with the strobe light in the B wavelength range, and temporarily storing the frame-sequential image data device to be stored, then e Bei recording means for recording on the recording medium, wherein the surface sequentially emitting the strobe is a adjusting means for adjusting R, G, B of the strobe light emission amount, respectively, preset Color It is characterized by having adjusting means for adjusting an emission amount of the flash light at the light-emitting portions that light of the same color temperature is emitted sequentially terms as to emit light based on the time information.
[0008]
That is, R, G, B strobe lights are emitted three times in a predetermined order from the surface sequential light emission strobe light, and three images corresponding to the R, G, B color strobe lights are acquired by the black and white imaging means. I am doing so. The frame sequential light emission strobe may be externally attached to the digital camera or may be built in.
[0009]
As a result, a high-resolution image can be obtained as compared with the color image pickup means having the same number of pixels, and the B image has a better SN than that obtained from the color image pickup means. Good printing is obtained.
[0010]
According to a second aspect of the present invention, there is provided recording means for recording the acquired R, G, B frame sequential image data on a recording medium. These three images of R, G, and B are appropriately combined and used for printing or reproduction.
[0011]
According to a third aspect of the present invention, there is provided a combining unit that combines the acquired R, G, and B frame sequential image data to generate one image, and a recording unit that records the generated image on a recording medium. It is characterized by having .
[0012]
Frame sequential light emitting flash with a digital camera according to 請 Motomeko 4, the frame sequential light emitting strobe that emits electronic flash light-sequential wavelength region of the plurality of light emitting diodes, an imaging unit, an imaging 3 times in one shutter release Control means for performing the light emission of the strobe light in the wavelength region of the plurality of light emitting diodes sequentially in a predetermined order from the surface sequential light emission strobe, and for each strobe light in the wavelength region of the plurality of light emitting diodes A control unit that causes the imaging unit to perform an imaging operation and obtains frame-sequential image data from the imaging unit; and a recording unit that stores the frame-sequential image data in a temporary storage device and then records the data in a recording medium. The surface sequential light emission strobe is an adjusting means for adjusting the light emission amount of the strobe light in the wavelength range of the plurality of light emitting diodes. Light of the same color temperature based on the color temperature information is characterized by having adjusting means for adjusting an emission amount of the flash light at the light-emitting portions that emit light in the field sequential as emission was.
According to a fifth aspect of the present invention, in the digital camera with a frame sequential light-emitting strobe according to the fourth aspect, the digital camera with the frame sequential light emission strobe includes recording means for recording the acquired frame sequential image data on a recording medium.
6. A digital camera with a field sequential light emission strobe as set forth in claim 4 , wherein a composition unit for composing the obtained field sequential image data to create one image and the created image data And a recording means for recording the image on a recording medium.
In the field sequential digital camera luminous flash of claim 1 or 4, as shown in 請 Motomeko 7, in automatic mode and manual for performing the color temperature set by reading the color temperature of the object field from the color temperature sensor A manual mode for setting a color temperature, and the adjusting means is a strobe light at each light emitting unit that emits light in a frame order so that light of the same color temperature is emitted based on the set color temperature information It is characterized by adjusting the amount of light emission of each.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a digital camera with a field-sequential light emission strobe according to the present invention will be described in detail with reference to the accompanying drawings.
[0014]
FIG. 1 is a block diagram showing an embodiment of a digital camera with a frame sequential light emission strobe according to the present invention.
[0015]
This digital camera with a frame sequential light emission strobe performs imaging while being fixed to a tripod. The digital camera has a monochrome image pickup device (CCD) 20 without a color filter and an external or built-in surface sequential light emission flash 50. If the shutter button is pressed, R, G, B strobe lights are emitted sequentially from the surface sequential light emission strobe 50, and images are taken for each color emission, and imaged three times with one shutter release. I do. The overall operation of the camera is centrally controlled by a central processing unit (CPU) 12.
[0016]
The operation unit 14 of the digital camera includes a power switch, a shutter button, a mode switching switch for switching between a shooting mode and a playback mode, a multi-function cross key for outputting various command signals such as zoom and frame advance. Various operation signals from the operation unit 14 are applied to the CPU 12.
[0017]
As described above, when the shutter button is pressed, the CPU 12 sequentially emits the R, G, and B strobe lights from the surface sequential light emission strobe 50 and controls the operation of the CCD 20 and the like for each color light emission for three sheets. Image data acquisition control is performed.
[0018]
That is, when a strobe light of a certain color among R, G, and B is emitted from the surface-sequential light-emitting strobe 50, the reflected light of the strobe light from the subject is a lens optical system 16 including a focus lens and an aperture 18. Then, an image is formed on the light receiving surface of the CCD 20. The signal charge accumulated in the CCD 20 is sequentially read out as a voltage signal corresponding to the signal charge by a transfer pulse applied from the CCD driver 22. The CCD 20 has a so-called electronic shutter function that controls the charge accumulation time (shutter speed) of each photosensor according to the timing of the shutter gate pulse.
[0019]
The voltage signal sequentially read from the CCD 20 is applied to the analog processing unit 24. The analog processing unit 24 includes a signal processing circuit such as a sampling hold circuit that performs correlated double sampling (CDS) processing, a gain adjustment circuit, and the like. The analog processed signal is converted into a digital signal ( (Hereinafter referred to as “CCDRAW data”) and then stored in a temporary storage device 28 such as an SDRAM.
[0020]
The temporary storage device 28 has a storage capacity capable of temporarily storing, for example, three or more pieces of CCDRAW data. The timing generator (TG) 30 provides timing signals to the CCD driver 22, the analog processing unit 24, and the A / D converter 26 in accordance with instructions from the CPU 12, and the circuits are synchronized by this timing signal. ing. The ROM 32 stores programs and adjustment values in advance, and these programs and adjustment values are read as appropriate.
[0021]
When the signal processing unit 34 stores three pieces of R, G, and B CCDRAW data in the temporary storage device 28 by three imaging operations, the signal processing unit 34 performs white balance on the R, G, and B CCDRAW data. Correction, gamma correction, luminance data Y and color difference data C _r and C _b generation processing (YC processing), contour enhancement processing, and the like are sequentially performed as signal processing. The image data processed by the signal processing unit 34 is encoded by a video encoder 38 and output to a liquid crystal monitor (LCD) 40 provided on the back of the camera, whereby a subject image is displayed on the display screen of the LCD 40. Is done.
[0022]
The CCDRAW data stored in the temporary storage device 28 is rewritten with the image data (YC data) processed by the signal processing unit 34, and the YC data stored in the temporary storage device 28 is sent to the compression / decompression processing unit 36. A predetermined compression process such as JPEG (joint photographic experts group) is executed and stored in the temporary storage device 28 again. The media controller 42 records the compressed data temporarily stored in the temporary storage device 28 on the memory card 10 via the card interface 44.
[0023]
Next, the surface sequential light emission strobe 50 will be described.
[0024]
The frame sequential light emission strobe 50 is mainly composed of a light emission control unit 51, an R light emission unit 52, a G light emission unit 53, and a B light emission unit 54.
[0025]
The light emission control unit 51 emits R, G, and B strobe lights in a predetermined order from the R light emission unit 52, the G light emission unit 53, and the B light emission unit 54 according to a command from the CPU 12, and for each of R, G, and B, respectively. When it is detected by the light control sensor or the like in the light emitting unit that the light emission amount set in (2) has reached the specified value, the light emission is stopped.
[0026]
In addition, as the R light emission part 52, the G light emission part 53, and the B light emission part 54, the thing provided with the color filter of R, G, B on the front surface of the light emitting diode of R, G, B, or a xenon tube, or It is conceivable to sequentially move R, G, B color filters to the front of one white strobe light source.
[0027]
Next, the operation of the digital camera with the surface sequential light emission strobe having the above-described configuration will be described with reference to the timing chart shown in FIG.
[0028]
First, upon receiving a strobe on signal (FIG. 2A) for performing strobe shooting from the CPU 12, the light emission control unit 51 starts charging a main capacitor (not shown). The main capacitor may be provided for each of the R light emitting unit 52, the G light emitting unit 53, and the B light emitting unit 54, and each of the R light emitting unit 52, the G light emitting unit 53, and the B light emitting unit 54 has electric energy. One main capacitor for supplying
[0029]
When charging of the main capacitor is completed, the charging operation is stopped (FIGS. 2B and 2C).
[0030]
Thereafter, when the shutter release button is half-pressed, the standby state is set (FIG. 2D), and the light emission control unit 51 takes in information for determining the flash light emission amount such as a guide number from the CPU 12. When the color temperature setting is in the auto mode, the color temperature of the object scene is read from a color temperature sensor (not shown), and in the manual mode, the color temperature set manually is read (FIG. 2E). ).
[0031]
The light emission control unit 51 determines the R, G, and B strobe light emission amounts based on the captured information, and sets the reference values for adjusting the light emission amount to obtain the strobe light emission amounts, respectively. The light is output to the light emitting unit 53 and the B light emitting unit 54. The ratio of the light emission amounts of the R light emission unit 52, the G light emission unit 53, and the B light emission unit 54 is set so that light having the same color temperature is emitted based on the color temperature of the object scene (FIG. 2). (F)).
[0032]
Next, when the shutter release button is fully pressed and the shutter is opened, a light emission signal synchronized with the opening of the shutter is input, and first, R strobe light with a predetermined light emission amount is emitted from the R light emitting unit 52 (FIG. 2). (G)). After completion of the strobe light emission, R CCDRAW data is taken in via the CCD 20, the analog processing unit 24 and the A / D converter 26 (FIG. 2 (F)) and stored in the temporary storage device 28.
[0033]
Subsequently, when the capture of the R CCD RAW data is completed, the G light emission unit 53 emits the G strobe light (FIG. 2G), and the G CCD RAW data is captured after the completion of the strobe light emission (FIG. 2F). ), When the acquisition of the CCD RAW data is completed, the B light emission unit 54 emits the B strobe light (FIG. 2G), and the B CCD RAW data is acquired after the end of the flash emission (FIG. 2F). .
[0034]
As described above, when R, G, and B frame sequential CCDRAW data is captured and stored in the temporary storage device 28 by three imaging operations, the signal processing unit 34 thereafter performs R, G, and R as described above. , B is processed by combining one color image from the CCDRAW data, and is recorded in the memory card 10.
[0035]
A color image can be printed by displaying the color image on a monitor based on the combined color image recorded on the memory card 10 or outputting the color image to a printer.
[0036]
Note that three image data of R, G, and B may be recorded in the memory card 10, and image data for color display is created from these three image data, or an image for printing. Data may be created.
[0037]
【The invention's effect】
As described above, according to the present invention, R, G, and B strobe lights are sequentially emitted from the field sequential light emission strobe light, and the R, G, and B surface sequential light is emitted by the black and white imaging means under the strobe light of each color. Since an image is obtained, a high-quality color image can be obtained by a monochrome imaging means without a color filter.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a digital camera with a frame sequential light emission strobe according to the present invention. FIG. 2 is a timing chart used to explain the operation of the digital camera with a field sequential light emission strobe according to the present invention. Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Memory card, 12 ... Central processing unit (CPU), 14 ... Operation part, 16 ... Lens optical system, 20 ... Image sensor (CCD), 24 ... Analog processing part, 26 ... A / D converter, 28 ... Temporary Storage device 34 ... Signal processing unit 36 ... Compression / decompression processing unit 42 ... Media controller 44 ... Card interface 50 ... Sequential light emission strobe 51 ... Light emission control unit 52 ... R light emission unit 53 ... G light emission unit 54 B light emitting part

Claims (7)

A surface-sequential light-emitting strobe that emits strobe light in the R, G, and B wavelength ranges;
Black and white imaging means;
Control means for performing imaging three times with one shutter release, and sequentially emits strobe light in a predetermined order in the wavelength ranges of R, G, and B from the surface sequential light emission strobe, and the R, G, and Control means for causing the imaging means to perform an imaging operation in synchronization with strobe light in the wavelength range of B, and acquiring R, G, B frame sequential image data from the imaging means;
Is stored in the temporary storage device image data of the surface sequentially, then e Bei recording means for recording on the recording medium, and
The frame sequential light emission strobe is an adjusting means for adjusting the light emission amounts of R, G, and B strobe lights, respectively, so that light having the same color temperature is emitted based on information on a preset color temperature. A digital camera with a frame-sequential light-emitting strobe, comprising adjusting means for adjusting the amount of flash light emitted from each light-emitting unit that emits light in a frame-sequential manner.   2. The digital camera with a frame sequential light emission strobe according to claim 1, further comprising recording means for recording the acquired frame sequential image data of R, G, B on a recording medium.   The image processing apparatus includes: a combining unit that combines the acquired R, G, and B frame sequential image data to generate one image data; and a recording unit that records the generated image data on a recording medium. The digital camera with a field sequential light emission strobe according to claim 1. A field-sequential light-emitting strobe that emits light in the wavelength range of a plurality of light-emitting diodes in a field-sequential manner;
Imaging means;
Control means for performing imaging three times with one shutter release, and sequentially emits strobe light in a wavelength range of the plurality of light emitting diodes from the surface sequential light emitting strobe in a predetermined order, and the plurality of light emitting diodes Control means for causing the imaging means to perform an imaging operation for each strobe light in the wavelength range of the image acquisition unit to obtain frame sequential image data from the imaging means;
Is stored in the temporary storage device image data of the surface sequentially, then e Bei recording means for recording on the recording medium, and
The frame sequential light emission strobe is an adjusting means for adjusting the light emission amount of strobe light in the wavelength region of a plurality of light emitting diodes, and emits light having the same color temperature based on information on a preset color temperature. A digital camera with a frame sequential light emission strobe having adjusting means for adjusting the amount of flash light emitted from each light emitting unit that emits light in a frame sequential manner. 5. The digital camera with a frame sequential light emission strobe according to claim 4 , further comprising recording means for recording the acquired frame sequential image data on a recording medium. 5. The frame sequential apparatus according to claim 4 , further comprising: a combining unit that combines the acquired frame sequential image data to generate a single image; and a recording unit that records the generated image data on a recording medium. Digital camera with flash. It has an auto mode that sets the color temperature by reading the color temperature of the object scene from the color temperature sensor and a manual mode that sets the color temperature manually.
The adjusting means adjusts the amount of strobe light emitted from each light emitting unit that emits light in a frame order so that light having the same color temperature is emitted based on the set color temperature information. The digital camera with a field sequential light emission strobe according to claim 1 or 4 .

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