JP2009122294A - Illuminator for photography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem, in the conventional illuminator for photography, that it is difficult to control emitted light quantities so that high-luminance LEDs of respective colors may emit light at aimed color temperature. <P>SOLUTION: "RGB balance for test light emission" that is a ratio of the emitted light quantities of the high-luminance LEDs 31a, 31b and 31c of respective colors is corrected by a control part 35 so that a difference between "non-light emission measurement RGB balance" that is first information showing the color temperature measured by a color temperature sensor 33 when an LED light emitting part 31 does not emit light and "test measurement RGB balance" that is second information showing the color temperature measured by the color temperature sensor 33 when the LED light emitting part 31 emits the light (S3 to S8) may be within a prescribed range. Then, the high-luminance LEDs 31a, 31b and 31c of the respective colors are made to emit the light in the corrected ratio of the emitted light quantities (S12). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photographing illumination device including a light emitting unit including a plurality of light emitting elements that emit light of different colors.

  Conventionally, a flash device using a xenon tube used in a camera is known as this type of illumination device for photographing. In general, a xenon tube is designed to emit light with light fixed at a color temperature of about 6000 K, which is a color temperature almost the same as daylight. For this reason, when using a flash device using a xenon tube and taking a flash photograph of a camera under light bulb illumination that emits light at, for example, about 3000K, an object in the field exposed to flash light from the xenon tube is captured. A difference of about 3000K occurs between the color temperature and the background color temperature due to the light bulb illumination, and the color balance is greatly different. For this reason, unnaturalness may occur in the photographed image, and a sense of incongruity may be felt.

In Patent Document 1 and Patent Document 2 below, in order to eliminate the above-described adverse effects, high-intensity LEDs (light emitting diodes) emitting three colors of red light, green light, and blue light are used. A strobe device for a camera capable of changing the light color is disclosed. In this strobe device, when the changeover switch is switched to the manual side, the color temperature of the strobe light is controlled so as to be the color temperature set by the color temperature setting volume. When the changeover switch is switched to the auto side, the color temperature of the strobe light is controlled so that the color temperature of the object scene detected by the color temperature sensor is obtained. The color temperature of the strobe light is controlled by controlling the amount of light emitted from the high-intensity LED of each color, and white balance processing is performed on an image that is illuminated and photographed with the strobe light.
Japanese Patent Laying-Open No. 2003-215673 (see paragraph [0025]) JP 2004-233714 A (see paragraphs [0035] and [0036])

  However, the LED has a delicate light emission characteristic, the light emission characteristic is likely to fluctuate due to temperature changes, and the light emission characteristic varies greatly due to individual manufacturing differences. For this reason, in the conventional photographing illumination device using the high-intensity LED as shown in Patent Document 1 and Patent Document 2 described above, the color temperature set by the color temperature setting volume or the color measured by the color temperature sensor Even if light of temperature is emitted by the high-brightness LEDs of each color, the color temperature of the light actually emitted varies due to the above-described variation in the light emission characteristics of the LEDs. Therefore, it has been difficult to control the amount of light emitted by the conventional illumination device for lighting so that the high-intensity LED of each color emits light at the target color temperature.

  A configuration for solving the above problems will be described with reference to the reference numerals of one embodiment. In addition, this invention is not necessarily limited to the thing of the structure of a code | symbol.

The present invention has been made to solve such problems,
A light emitting means (31) including a plurality of light emitting elements (31a, 31b, 31c) that emit light of different colors;
Color temperature measuring means (33) for measuring the color temperature of the object scene;
In the illuminating device for photographing (3) comprising the control means (35) for controlling the light emission of the light emitting means,
The control means (35)
First information, which is information on the color temperature measured by the color temperature measuring means (33) when the light emitting means (31) is not emitting light, and measured by the color temperature measuring means (33) when the light emitting means (31) emits light. Based on the difference from the second information that is the color temperature information, the light emission amount ratio of the light emitting elements (31a, 31b, 31c) of each color so that the difference between the second information and the first information is within a predetermined range. To correct
The light emitting elements (31a, 31b, 31c) of each color are caused to emit light with the corrected light emission amount ratio.

  According to this configuration, the control unit measures (actually measures) the first information, which is information on the color temperature measured by the color temperature measuring unit when the light emitting unit is not emitting light, and the color temperature measuring unit when the light emitting unit emits light. The light emission amount ratios of the light emitting elements of the respective colors are corrected so that the difference from the second information that is the information of the color temperature is within a predetermined range, and the light emitting elements of the respective colors are caused to emit light at the corrected light emission amount ratio. For this reason, even if light emitting elements having variations in light emission characteristics are used in the illuminating lighting device, the light emitting elements of the respective colors have the first information by the light emission control of the control means that feeds back the color temperature information during actual light emission. And the second information are caused to emit light with a corrected light emission amount ratio that is within a predetermined range. Accordingly, the color temperature of the light emitted from the photographing illumination device corresponding to the second information is different from the color temperature of the object scene corresponding to the first information within a predetermined range. As a result, even if light-emitting elements having variations in light emission characteristics are used in the photographing illumination device, the variation in the color temperature of the light emitted from the photographing illumination device is within a predetermined range, and the light emitted from the photographing illumination device The color temperature is controlled within an allowable error range of the target color temperature.

  Further, the present invention is characterized in that the control means (35) starts exposure immediately after correction and causes the light emitting elements (31a, 31b, 31c) of each color to emit light at the corrected light emission amount ratio.

  According to this configuration, after the light emission amount ratio of the light emitting elements of each color is corrected by the control means, exposure is automatically started immediately, and the light emitting elements of each color are caused to emit light at the corrected light emission amount ratio. For this reason, exposure is performed in a state where the light emission amount ratio of the light emitting elements of the respective colors is automatically corrected to an appropriate value, and the possibility of missing a photo opportunity is reduced.

The present invention further includes a storage means (35) for storing the corrected light emission amount ratio,
The control means (35) causes the light emitting elements (31a, 31b, 31c) of each color to emit light at the corrected light emission amount ratio stored in the storage means (35) during exposure.

  According to this configuration, the corrected light emission amount ratio is stored in the storage unit, and at the time of exposure, the light emitting elements of each color are caused to emit light by the control unit with the corrected light emission amount ratio stored in the storage unit. For this reason, the photographer can perform photographing by causing the light emitting elements of the respective colors to emit light at the corrected light emission amount ratio stored in advance in the storage unit before photographing.

The present invention also includes a luminance measuring means (32) for measuring the field luminance.
When the field brightness measured by the brightness measuring means (32) is smaller than a predetermined value, the control means (35) causes each color light emitting element (31a, 31b, 31c) to emit light at a predetermined light emission amount ratio. Features.

  According to this configuration, when the field luminance measured by the luminance measuring unit is smaller than the predetermined value, the light emitting element of each color has a predetermined light emission amount without correcting the light emission amount ratio by the control unit. The light is emitted at a ratio. For this reason, even when the field brightness is low and the color temperature measurement means does not properly measure the color temperature of the field, the light emitting elements of each color emit light at a predetermined light emission ratio. And photography is performed appropriately.

  Further, according to the present invention, the control means (35) corrects the light emission amount ratio until the difference between the first information and the second information converges within a predetermined range, and for each color at the corrected light emission amount ratio. The light emitting element (31a, 31b, 31c) repeats the light emitting operation.

  According to this configuration, until the difference between the first information and the second information converges within a predetermined range, the operation of correcting the light emission amount ratio of the light emitting elements of each color, and the light emission amount ratio corrected by this correction operation for each color. The operation of causing the light emitting element to emit light is repeatedly performed. Therefore, the correction of the light emission amount ratio of the light emitting elements of each color is performed while the light emitting elements of each color actually emit light with the corrected light emission amount ratio, and the color temperature at the corrected light emission amount ratio is measured and verified. . Therefore, the correction of the light emission amount ratio is performed more accurately, and the variation in the color temperature of the light emitted from the photographing illumination device is surely within the predetermined range.

  Further, according to the present invention, if the difference does not converge within a predetermined range even if the control means (35) performs the correction operation a predetermined number of times, each color light emitting element (31a, 31b, 31c) with a specific light emission amount ratio. Is characterized by emitting light.

  According to this configuration, if the difference between the first information and the second information does not converge within a predetermined range even if the correction operation is performed a predetermined number of times, the light emitting elements of each color are caused to emit light at a specific light emission amount ratio. For this reason, even if the difference between the first information and the second information does not converge within a predetermined range by a predetermined number of correction operations due to the influence of noise light in the object scene, the light emitting elements of each color are not specified. Shooting is performed appropriately by emitting light at a light emission ratio. Further, since the correction operation is prevented from being repeatedly performed more than a predetermined number of times, it is possible to prevent a situation in which the light emission amount ratio of the light emitting elements of the respective colors is not fixed forever.

  According to the illuminating device for photographing according to the present invention, as described above, even when light emitting elements having variations in light emission characteristics are used in the illuminating device for photographing, the color temperature when actually illuminated is measured, and based on the measured temperature. Therefore, the variation in the color temperature of the light emitted from the photographing illumination device is within a predetermined range, and the color temperature of the light emitted from the photographing illumination device is controlled within an allowable error range of the target color temperature. Become so.

  Next, the best mode for carrying out the present invention will be described.

  FIG. 1 is a front view showing an external appearance of an electronic camera provided with a photographing illumination device according to the present embodiment.

  The electronic camera includes a camera unit 1 and an optical lens unit 2, and the photographing illumination device 3 according to the present embodiment is detachably attached to the camera unit 1 via a hot shoe 4. The illuminating device 3 includes an LED light emitting unit 31, a light control sensor 32, and a color temperature sensor 33, and is controlled to emit light according to a control signal received from the camera unit 1 via the hot shoe 4. The LED light emitting unit 31 is composed of three color high-intensity LEDs that emit light of three colors, red (R) light, green (G) light, and blue (B) light. The light control (photometry) sensor 32 detects light from the object scene and measures the field luminance. The color temperature sensor 33 is configured, for example, by applying a color filter to a PD (photodiode), and detects light from the object scene to measure the color temperature of the object scene. A subject in the object scene is illuminated by the illumination device 3, and light from the object field is guided to the camera unit 1 through the optical lens unit 2.

  FIG. 2 is a block diagram illustrating an internal configuration of the electronic camera and the illumination device 3 described above.

  Each element in the camera unit 1 is electrically connected to each other via a bus 17 and is controlled by the control unit 11. The shutter 5 is opened in response to an operation of a shutter button (not shown) by the photographer, and light from the object field guided through the optical lens unit 2 is imaged on the light receiving surface of the image sensor 6. The image sensor 6 is formed of, for example, a well-known CCD (Charge Coupled Device) sensor or CMOS (Complementary Metal Oxide Semiconductor) sensor. The object scene image formed on the light receiving surface of the image pickup device 6 via the optical lens unit 2 and the shutter 5 is converted into an image pickup signal made up of electric signals representing each color information of red, green and blue. The imaging signal is amplified by the signal amplifier 7, converted to a digital signal by the A / D converter 8, and temporarily stored as image data in the buffer memory 9. The digital image processing unit 10 performs image processing such as white balance processing and gamma correction on the image data temporarily stored in the buffer memory 9. An image recording element 12 such as a memory card which is detachable from the camera finally stores the image data processed by the digital image processing unit 10. The display device 13 is composed of an LCD (liquid crystal display device) provided on the back surface of the camera unit 1 and displays the image data stored in the image recording element 12 on a monitor. The operation unit 14 is operated when performing various camera operations or when selecting a white balance mode described later.

  The lens I / F 15 transmits and receives signals to and from the optical lens unit 2, and the illumination device I / F 16 transmits and receives signals to and from the illumination device 3.

  The optical lens unit 2 in this embodiment includes a zoom lens 21 that continuously changes the focal length, a focus lens 22 that adjusts the focus, and a diaphragm 23 that adjusts the exposure. These are controlled by the control unit 24. The Based on the control signal from the lens I / F 15 of the camera unit 1, the control unit 24 adjusts the focal length of the zoom lens 21, the focus of the focus lens 22, and the aperture adjustment by the aperture 23.

  The lighting device 3 includes an LED light emitting unit 31 and a sensor unit 34, which are controlled by a control unit 35. The LED light emitting unit 31 constitutes light emitting means including a high luminance LED 31a that is a red light emitting element that emits red light, a high luminance LED 31b that is a green light emitting element that emits green light, and a high luminance LED 31c that is a blue light emitting element that emits blue light. is doing. The control unit 35 constitutes a control means for controlling the light emission of the LED light emitting unit 31, and the light emission amounts of the high-intensity LEDs 31a, 31b, 31c of the respective colors are individually controlled by the control unit 35. The sensor unit 34 includes the light control sensor 32 and the color temperature sensor 33 described above. The light control sensor 32 constitutes luminance measuring means for measuring the field luminance, and the color temperature sensor 33 constitutes color temperature measuring means for measuring the color temperature of the object scene.

  In the present embodiment, the control unit 35 includes the first information that is information on the color temperature measured (colorimetric) by the color temperature sensor 33 when the LED light emitting unit 31 is not emitting light, and the color temperature when the LED light emitting unit 31 emits light. Based on the difference from the second information, which is information on the color temperature measured (colorimetric / actually measured) by the sensor 33, the difference between the second information and the first information is within a predetermined range, as will be described later. Then, the light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of each color is corrected, and the high-intensity LEDs 31a, 31b, and 31c of each color are caused to emit light at the corrected light emission amount ratio. The control unit 35 includes a memory (not shown) that stores the corrected light emission amount ratio for the high-intensity LEDs 31a, 31b, and 31c of each color as a storage unit.

  In the present embodiment, the adjustment of the white balance of the subject illuminated at the time of shooting by the illumination device 3 is any one selected from the two modes of the auto white balance mode and the measurement white balance mode by operating the operation unit 14. It is performed based on the mode. In the auto white balance mode, the light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c for each color at the time of exposure is automatically determined based on the result of color measurement by the color temperature sensor 33 before the actual exposure operation. In this mode, shooting is performed. When the auto white balance mode is selected, the control unit 35 starts the exposure immediately after correcting the light emission amount ratios of the high-intensity LEDs 31a, 31b, and 31c of the respective colors, and each color of each color is corrected with the corrected light emission amount ratio. The high brightness LEDs 31a, 31b, and 31c are caused to emit light. In the measurement white balance mode, the light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of each color at the time of exposure is stored at the time of measurement photography performed in advance by the user before performing the actual photographing operation. In this mode, shooting is performed based on the stored light emission amount ratio during actual shooting. This pre-exposure measurement photography (pre-measurement photography) is performed by photographing an achromatic object (for example, a gray plate) as preparation work for the actual photography, and must be performed under the same environmental illumination as the actual photography. There is, but we can expect accurate color reproduction. When the measurement white balance mode is selected, the control unit 35 causes the high-intensity LEDs 31a, 31b, and 31c of each color to emit light at the corrected light emission amount ratio stored in the memory in the control unit 35 at the time of exposure. .

  FIG. 3 is a flowchart showing an outline of the light emission control processing performed by the control unit 11 of the camera unit 1 and the control unit 35 of the illumination device 3 when the auto white balance mode is selected and camera shooting is performed.

  In this light emission control process, first, the controller 11 of the camera unit 1 determines whether or not the shutter button has been pressed (see S1 in FIG. 3). The determination of S1 is repeatedly performed until the determination is “YES” after the shutter button is pressed. When the shutter button is pressed and the determination of S1 is “YES”, a control signal is transmitted from the control unit 11 of the camera unit 1 to the control unit 35 of the lighting device 3 via the lighting device I / F 16. The control unit 35 measures the field luminance (photometry) using the light control sensor 32. Subsequently, the control unit 35 determines whether or not the measured field luminance is larger than a preset threshold value (S2). When the measured field luminance is larger than a preset threshold value and this determination is “YES” (that is, when ambient light (ambient illumination light) is present), first, the control unit 35 controls each color. In the non-light-emitting state in which the high-intensity LEDs 31a, 31b, and 31c are not lit, the color temperature of the object field, that is, the RGB balance that is the ratio of each color of red (R), green (G), and blue (B) 33 (S3). The RGB balance obtained by this measurement is stored in a predetermined area of the memory in the control unit 35 as “non-light emission measurement RGB balance” as the first information. Subsequently, the “non-emission measurement RGB balance” measured in the process of S3 is stored in a predetermined area of the memory in the control unit 35 as “test emission RGB balance” (S4). . “RGB balance for test light emission” is a light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of the respective colors when the LED light emitting unit 31 is caused to perform test light emission before exposure.

  Next, the control unit 35 causes the high-brightness LEDs 31a, 31b, and 31c of each color to perform test light emission at a light emission amount ratio corresponding to the “test light emission RGB balance” stored in the memory in S4 (S5). Subsequently, the RGB balance of the object scene using the color temperature sensor 33 is measured by the control unit 35 in a state where the high-intensity LEDs 31a, 31b, and 31c of the respective colors are subjected to the test light emission by the process of S5 (actual Luminescent color temperature measurement). The RGB balance obtained by this measurement is stored in a predetermined area of the memory in the control unit 35 as “test measurement RGB balance” as the second information (S6). Subsequently, the control unit 35 compares the “non-light emission measurement RGB balance” measured in S3 with the “test measurement RGB balance” measured in S6, and the difference (difference) between these RGB balances is within a predetermined range. It is determined whether or not it is within (S7). When the difference between the RGB balances is not within the predetermined range and the determination result is “NO”, the control unit 35 uses the difference between the two to measure “test measurement RGB balance”. The obtained “test light emission RGB balance” is brought close to the “non-light emission measurement RGB balance”, and the difference in RGB balance falls within a predetermined range with the light emission amount ratio of the high-intensity LEDs 31a, 31b, 31c of each color. A certain “test light emission RGB balance” is corrected (S8).

  When the difference between the “non-light emission measurement RGB balance” and the “test measurement RGB balance” is within a predetermined range and the determination in S7 is “YES”, or when the processing in S8 is completed, In addition, the control unit 35 corrected the “test emission RGB balance” used for the measurement of “test measurement RGB balance” in which the difference was within the predetermined range in the process of S7 or the process of S8. “Test light emission RGB balance” is determined as “light emission RGB balance” (S9). The “light emission RGB balance” is a light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of each color when the LED light emitting unit 31 emits light during exposure, and “test light emission RGB balance” determined as “light emission RGB balance”. A data table (not shown) is referred to and calculated from the “balance” value. Further, in the determination of S2 by the control unit 35, when the object scene luminance measured by the light control sensor 32 is equal to or less than a preset threshold, the object scene is dark, and the determination result of S2 is “NO”. Is assumed that there is no ambient light (ambient illumination light), the processing of S3 to S9 is not performed, and a preset color temperature, for example, a color temperature of 5000K corresponding to sunlight, is “light emitting RGB It is determined as “balance” (S10).

  In the present embodiment, in the processing of S9 or S10 described above, when the light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of each color at the time of exposure is determined as “light emission RGB balance”, the LED light emission unit 31 emits light. The reflectance of the reflected light from the object scene is measured by the light control sensor 32, and the light emission amounts of the high-intensity LEDs 31a, 31b, 31c of the respective colors are also determined at the same time. When the light emission amount ratio and the light emission amount of the high-intensity LEDs 31a, 31b, and 31c for each color are determined, a light emission preparation completion signal is transmitted from the control unit 35 of the illumination device 3 to the control unit 11 of the camera unit 1 via the illumination device I / F 16. Is sent.

  When this signal is received by the control unit 11 of the camera unit 1, the shutter 5 is opened and exposure is started under the control of the control unit 11 (S11). Subsequently, the control unit 35 of the illumination device 3 The high-intensity LEDs 31a, 31b, and 31c of each color are caused to emit light with the “light emission RGB balance” and the light emission amount determined in the process of S9 or S10 (S12). Thereafter, when a time corresponding to the shutter speed elapses, the shutter 5 is closed by the control unit 11 of the camera unit 1, and the light emission of the high-intensity LEDs 31a, 31b, and 31c of each color is terminated by the control unit 35 of the illumination device 3. The exposure ends (S13). Subsequently, the control unit 11 of the camera unit 1 performs various types of image processing on the image data captured by the image sensor 6 from the start of exposure in S11 to the end of exposure in S13 (S14), thereby controlling light emission. The process ends. In the image processing in S14, the “non-light emission measurement RGB balance” measured in S3 is referred to, and white balance processing for the image data of the subject in the imaged field and image processing such as gamma correction are performed. . In this white balance process, the light color of the light emitted in the process of S12 and applied to the subject has already been adjusted to be equal to the ambient light of the object field, and can be ignored. This is equivalent to the case where the light emitting unit 31 does not emit light. The image data subjected to the image processing is stored in the image recording element 12 of the camera unit 1 and displayed on the display device 13 on a monitor.

  4 and 5 are flowcharts showing an outline of the light emission control processing performed by the control unit 11 of the camera unit 1 and the control unit 35 of the illumination device 3 when the measurement white balance mode is selected and camera shooting is performed. is there.

  FIG. 4 shows an outline of the light emission control process during measurement photographing when the measurement white balance mode is selected. The subject at the time of performing measurement photography in FIG. 4 is the achromatic object (gray plate or the like) described above. It is assumed that the environmental lighting is the same environment as the environmental lighting that performs the actual photographing.

  In the light emission control process at the time of measurement photographing, first, it is determined by the control unit 11 of the camera unit 1 whether or not the shutter button has been pressed (see S21 in FIG. 4). The determination in S21 is repeatedly performed until the determination is “YES” after the shutter button is pressed. When the shutter button is pressed and the determination in S21 is “YES”, a control signal is transmitted from the control unit 11 of the camera unit 1 to the control unit 35 of the lighting device 3 via the lighting device I / F 16. The control unit 35 measures the field luminance using the light control sensor 32. Subsequently, the control unit 35 determines whether or not the measured field luminance is larger than a preset threshold value (S22). When the measured field luminance is greater than a preset threshold value and this determination is “YES”, the control unit 35 causes the high-brightness LEDs 31a, 31b, 31c of the respective colors to emit light in a non-light-emitting state. The RGB balance is measured using the color temperature sensor 33 (S23). The RGB balance obtained by this measurement is stored in a predetermined area of the memory in the control unit 35 as “non-light emission measurement RGB balance” as the first information. Subsequently, the “non-emission measurement RGB balance” measured in the process of S23 is stored in the predetermined area of the memory in the control unit 35 as “test emission RGB balance” (S24). .

  Next, the control unit 35 causes the high-brightness LEDs 31a, 31b, 31c of each color to emit test light at a light emission amount ratio corresponding to the “test light emission RGB balance” stored in the memory in S24 (S25). Subsequently, the RGB balance of the object scene using the color temperature sensor 33 is measured by the control unit 35 in a state where the high-intensity LEDs 31a, 31b, 31c of the respective colors are subjected to the test light emission by the process of S25. The RGB balance obtained by this measurement is stored as a second information “test measurement RGB balance” in a predetermined area of the memory in the control unit 35 (S26). Subsequently, the control unit 35 compares the “non-light emission measurement RGB balance” measured in S23 with the “test measurement RGB balance” measured in S26, and the difference (difference) between these RGB balances is within a predetermined range. It is determined whether or not it is within (S27). When the difference between the RGB balances is not within the predetermined range and this determination is “NO”, the control unit 35 performs “test measurement RGB balance” in the same manner as described in S8 of FIG. The “test light emission RGB balance” used in the measurement is brought close to the “non-light emission measurement RGB balance” so that the difference in each RGB balance falls within a predetermined range. The “test light emission RGB balance” which is the light emission amount ratio is corrected (S28).

  Subsequently, the control unit 35 determines whether or not the number of times that the correction operation of S28 is repeatedly performed is equal to or less than a predetermined number (S29). When the number of times that the correction operation has been repeatedly performed is equal to or less than the predetermined number and this determination is “YES”, the process returns to S25, and the processes of S25 to S28 described above are repeated. On the other hand, when the number of times that the correction operation of S28 is repeatedly performed exceeds the predetermined number and the determination of S29 is “NO”, or in the determination of S22, the field luminance measured by the light control sensor 32 is When it is determined that there is no ambient light (ambient illumination light) below the preset threshold and the determination in S22 is “NO”, the control unit 35 sets a preset color temperature, for example, the sun. A color temperature of 5000 K corresponding to light is determined as “light emission RGB balance” (S30).

  If the difference between the “non-light emission measurement RGB balance” and the “test measurement RGB balance” is within a predetermined range and the determination in S27 is “YES”, the control unit 35 performs the process of S27. The “test emission RGB balance” used for the measurement of the “test measurement RGB balance” whose difference is within the predetermined range is determined as the “emission RGB balance” (S31).

  In the present embodiment, the processing of S9 or S10 is also performed when the light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of each color at the time of exposure is determined as “light emission RGB balance” in the processing of S30 or S31. As in the above, the reflectance of the light emitted from the LED light emitting unit 31 from the object field is measured by the light control sensor 32, and at the same time, the light emission amounts of the high-intensity LEDs 31a, 31b, and 31c of the respective colors are determined.

  When the processing of S30 or S31 ends, the control unit 35 determines that the “non-light emission measurement RGB balance” measured in S23 and the “light emission RGB balance” and the light emission amount determined in S30 or S31 are the control unit 35. Is stored in a predetermined area of the internal memory (S32). When the “non-emission measurement RGB balance”, “emission RGB balance”, and the light emission amount are stored in the memory, the control unit 35 of the illumination device 3 transmits the illumination unit I / F 16 to the control unit 11 of the camera unit 1. A measurement imaging end signal is transmitted.

  FIG. 5 shows an outline of the light emission control process at the time of actual photographing when the measurement white balance mode is selected.

  In the light emission control processing at the time of the main photographing, first, the control unit 35 of the illumination device 3 determines that the “non-light emission measurement RGB balance”, the “light emission RGB balance”, and the light emission amount stored in the memory in FIG. It is read from the memory (see S41 in FIG. 5). Next, the shutter 5 is opened by the control unit 11 of the camera unit 1 to start exposure (S42). Subsequently, the high-luminance LEDs 31a, 31b, 31c of the respective colors are caused to emit light by the “light emission RGB balance” and the light emission amount read in the process of S41 by the control unit 35 of the illumination device 3 (S43). Thereafter, when a time corresponding to the shutter speed elapses, the shutter 5 is closed by the control unit 11 of the camera unit 1, and the light emission of the high-intensity LEDs 31a, 31b, and 31c of each color is terminated by the control unit 35 of the illumination device 3. The exposure ends (S44). Subsequently, the control unit 11 of the camera unit 1 performs various types of image processing on the image data captured by the image sensor 6 from the start of exposure in S42 to the end of exposure in S44 (S45), thereby controlling light emission. The process ends. In the image processing in S45, the “non-light emission measurement RGB balance” read out in S41 is referred to, and white balance processing, image processing such as gamma correction, and the like is performed on the image data of the subject in the captured field. Is called. The image data subjected to the image processing is stored in the image recording element 12 of the camera unit 1 and displayed on the display device 13 on a monitor.

  According to the illuminating device 3 according to the present embodiment as described above, in both the auto white balance mode and the measurement white balance mode, as described above, the color temperature sensor 33 is controlled by the control unit 35 when the LED light emitting unit 31 does not emit light. “Non-emission measurement RGB balance”, which is the first information of the color temperature measured in Step 1, and “Test measurement RGB balance”, which is the second information of the color temperature measured by the color temperature sensor 33 when the LED light emitting unit 31 emits light. In the pre-shooting operation before the automatic exposure in the auto white balance mode and before the main shooting operation in the measurement white balance mode, the high-intensity LEDs 31a, 31b, and 31c of the respective colors are previously set so that the difference between them is within a predetermined range. The light emission amount ratio is corrected (see FIGS. 3, S8, 4 and S28). Each color of high luminance LED31a ratio, 31b, 31c are caused to emit light (FIG. 3, S12, see FIG. 5, S43). For this reason, even if LEDs having variations in light emission characteristics are used in the illumination device 3, the high-intensity LEDs 31a of the respective colors are used during actual photographing by the light emission control of the control unit 35 that feeds back color temperature information during actual light emission. , 31b, 31c are caused to emit light at a corrected light emission amount ratio in which the difference between the “non-light emission measurement RGB balance” as the first information and the “test measurement RGB balance” as the second information is within a predetermined range. Accordingly, the color temperature of the light emitted from the lighting device 3 corresponding to the second information is different from the color temperature of the object scene corresponding to the first information within a predetermined range. As a result, even if LEDs having variations in light emission characteristics are used in the lighting device 3, the variation in the color temperature of the light emitted from the lighting device 3 is within a predetermined range, and the color temperature of the light emitted from the lighting device 3 is The target color temperature is controlled within an allowable error range.

  In the present embodiment, in the auto white balance mode, the control unit 35 corrects the light emission amount ratio of the high-brightness LEDs 31a, 31b, and 31c of the respective colors (see FIG. 3 and S8), and then the exposure is automatically performed immediately. This is started (see FIG. 3, S11), and the high-intensity LEDs 31a, 31b, 31c of the respective colors are caused to emit light with the corrected light emission amount ratio “RGB balance for light emission” (FIG. 3, S12). For this reason, exposure is performed in a state in which the light emission amount ratios of the high-intensity LEDs 31a, 31b, and 31c of the respective colors are automatically corrected to appropriate values, and it is troublesome for the photographer at the time of shooting (necessary for measurement white balance mode Pre-measurement work). In addition, since automatic correction is performed immediately after shooting, there is less risk of missing a photo opportunity.

  Further, in the measurement white balance mode in the present embodiment, the pre-corrected light emission amount ratio “RGB balance for light emission” is stored in advance in a predetermined area of the memory in the control unit 35 (see FIG. 4, S32), and at the time of exposure. The high-luminance LEDs 31a, 31b, and 31c for each color are caused to emit light by the control unit 35 with the corrected “light emission RGB balance” stored in the memory (see FIGS. 5, S41, and S43). Therefore, at the time of actual photographing, the photographer performs actual photographing by causing the high-intensity LEDs 31a, 31b, and 31c of each color to emit light with the corrected “RGB balance for light emission” stored in the memory in advance before photographing. Is possible.

  In the present embodiment, when the field luminance measured by the light control sensor 32 is smaller than a predetermined value, the high luminance LEDs 31a, 31b, 31c of the respective colors are corrected by the control unit 35 for the light emission amount ratio. The light is emitted at a predetermined light emission amount ratio of a fixed value (see FIGS. 3, S2, S10, FIGS. 4, S22, and S30). For this reason, even when the field brightness is low and the color temperature sensor 33 does not appropriately measure the color temperature of the field, the high-brightness LEDs 31a, 31b, and 31c of the respective colors emit predetermined light. Light is emitted at a quantitative ratio, and photographing is performed appropriately.

  Further, in the present embodiment, during the pre-measurement (correction) operation in the measurement white balance mode, the difference between the “non-light emission measurement RGB balance” that is the first information and the “test measurement RGB balance” that is the second information is within a predetermined range. Operation for correcting the light emission ratio of the high-intensity LEDs 31a, 31b, 31c for each color (see FIG. 4, S28) until it converges, and the high-intensity LEDs 31a, 31b, 31b for each color at the light emission ratio corrected by this correction operation. The operation of emitting light 31c (see FIG. 4, S25) is repeatedly performed (see FIG. 4, S25-S29). For this reason, the correction of the light emission amount ratio of the high-intensity LEDs 31a, 31b, 31c of each color is performed by actually emitting the high-intensity LEDs 31a, 31b, 31c of each color with the “test light emission RGB balance” of the corrected light emission amount ratio. This is performed while the color temperature at the corrected emission amount ratio is measured and verified. Therefore, the correction of the light emission amount ratio is performed more accurately, and the variation in the color temperature of the light emitted from the illumination device 3 is surely kept within the predetermined range.

  In the present embodiment, in the measurement white balance mode, even if the correction operation is performed a predetermined number of times, there is a difference between “non-light emission measurement RGB balance” that is the first information and “test measurement RGB balance” that is the second information. When it does not converge within the predetermined range, it is treated as an error, and the high-intensity LEDs 31a, 31b, 31c of each color are caused to emit light at a specific light emission amount ratio (see FIGS. 4, S29, S30). For this reason, the difference between the “non-light emission measurement RGB balance” that is the first information and the “test measurement RGB balance” that is the second information is within a predetermined range due to a predetermined number of correction operations due to the influence of noise light in the object scene. Even when the light does not converge, the high-intensity LEDs 31a, 31b, and 31c of the respective colors are caused to emit light at a specific light emission amount ratio, and photographing is appropriately performed. Further, since the correction operation is prevented from being repeatedly performed over a predetermined number of times, it is possible to prevent a situation in which the light emission amount ratio of the high-intensity LEDs 31a, 31b, and 31c of each color is not fixed forever. .

  In the above-described embodiment, measurement of “non-light emission measurement RGB balance” (see FIGS. 3, S3, FIG. 4, S23) and measurement of “test measurement RGB balance” (see FIGS. 3, S6, FIG. 4, S26). The color temperature sensor 33 provided in the illumination device 3 is used, and the luminance of the object scene (see FIGS. 3, S2, 4, and S22) is measured using the light control sensor 32 provided in the illumination device 3. However, the present invention is not limited to this. The measurement of each RGB balance and the measurement of the field luminance is a method called TTL (Through the Lens) photometry that measures the object field image formed on the light receiving surface of the image sensor 6 through the optical lens unit 3. It is also possible to do this. According to the measurement by the TTL photometry, the RGB balance and the field luminance are measured with respect to the field image actually formed on the image pickup device 6, so that the high-brightness LEDs 31a, 31b, and 31c for each color are measured. The light emission amount ratio and the light emission amount are adjusted more accurately.

  Moreover, although the said embodiment demonstrated the case where the field brightness and the color temperature of a field were measured using the separate sensor called the light control sensor 32 and the color temperature sensor 33, respectively (FIG. 1, FIG. 2). The present invention is not limited to this. It is also possible to adopt a configuration in which the field luminance and the color temperature of the field are measured with a single sensor.

  Moreover, although the said embodiment demonstrated the case where the illuminating device 3 became the structure attached to the camera unit 1 (refer FIG. 1, FIG. 2), this invention is not limited to this. The illumination device 3 may be built in the camera unit 1.

  In the above-described embodiment, a case has been described in which the correction for bringing the “test emission RGB balance” closer to the “non-emission measurement RGB balance” is repeatedly performed when the measurement white balance mode is selected (FIG. 4). , S25 to S29), the present invention is not limited to this. It is also possible to employ a configuration in which the above correction is repeatedly performed a plurality of times (predetermined times) when the auto white balance mode is selected.

  In the above-described embodiment, the LED light emitting unit 31 includes the high-intensity LED 31a that emits red light, the high-intensity LED 31b that emits green light, and the high-intensity LED 31c that emits blue light as a plurality of light-emitting elements that emit light of different colors. Although the case where it was comprised including was demonstrated (refer FIG. 2), this invention is not limited to this. For example, the LED light emitting unit 31 may include not only the red light, green light, and blue light but also a high-luminance LED that emits another color.

  Moreover, although the case where high-intensity LED was used as a light emitting element was demonstrated in the said embodiment (refer FIG. 2), this invention is not limited to this. For example, an organic EL (electroluminescence) or plasma light emitting element can be used as the light emitting element.

  In the above embodiment, when the measurement white balance mode is selected and the field luminance measured by the light control sensor 32 is smaller than a preset threshold value (see FIG. 4, S22), This is the same regardless of whether the number of times that the correction for bringing the “test light emission RGB balance” closer to the “non-light emission measurement RGB balance” is repeated exceeds a predetermined number (see FIG. 4, S29). Although the case where the fixed color temperature is set as the light emission RGB balance has been described (see FIG. 4, S30), the different fixed value color temperatures may be set as the “light emission RGB balance”. Absent.

  Even when the lighting device according to the present embodiment is modified to any of the above-described configurations, the same effects as those of the above-described embodiment can be obtained.

  In the above embodiment, the case where the illumination device for photographing according to the present invention is applied to an electronic camera has been described. However, according to the present invention, other types of cameras such as a film camera, a mobile phone with a camera, a surveillance camera, and the like It is also possible to apply a photographing illumination device. Even when the photographing illumination device according to the present invention is applied to such a device, the same effects as those of the above-described embodiment can be obtained.

It is a front view which shows the external appearance of the electronic camera provided with the imaging | photography illumination device by one Embodiment of this invention. It is a block diagram which shows the internal structure of the electronic camera and imaging | photography illumination device which are shown in FIG. It is a flowchart which shows the outline of the light emission control process in case an auto white balance mode is selected and camera imaging | photography is performed. It is a flowchart which shows the outline of the light emission control process at the time of measurement imaging | photography in case measurement white balance mode is selected and camera imaging | photography is performed. It is a flowchart which shows the outline of the light emission control processing at the time of the main imaging | photography in case measurement white balance mode is selected and camera imaging | photography is performed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Camera unit 2 ... Optical lens unit 3 ... Illuminating device 4 ... Hot shoe 5 ... Shutter 6 ... Image sensor 7 ... Signal amplifier 8 ... A / D converter 9 ... Memory 10 ... Digital image processing part 11, 35 ... Control part DESCRIPTION OF SYMBOLS 12 ... Image recording element 14 ... Operation part 16 ... Illuminating device I / F
31 ... LED light emission part 31a, 31b, 31c ... High brightness LED
32 ... Light control sensor 33 ... Color temperature sensor 34 ... Sensor unit

Claims (6)

A light emitting means including a plurality of light emitting elements that emit light of different colors;
Color temperature measuring means for measuring the color temperature of the object field;
A photographing illumination device comprising: control means for controlling light emission of the light emitting means;
The control means includes
First information, which is information on the color temperature measured by the color temperature measuring means when the light emitting means is not emitting light, and second information, which is information on the color temperature measured by the color temperature measuring means when the light emitting means emits light. Based on the difference with the information, the light emission amount ratio of the light emitting elements of each color is corrected so that the difference between the second information and the first information is within a predetermined range,
The illuminating device for photographing, wherein the light emitting elements of the respective colors are caused to emit light at the corrected light emission amount ratio.   2. The photographing illumination device according to claim 1, wherein the control unit starts exposure immediately after the correction and causes the light emitting elements of the respective colors to emit light at the corrected light emission amount ratio. A storage unit for storing the corrected light emission amount ratio;
2. The photographing illumination device according to claim 1, wherein the control unit causes the light emitting elements of the respective colors to emit light at the corrected light emission amount ratio stored in the storage unit during exposure. Provided with a luminance measuring means for measuring the field luminance,
The said control means makes the light emitting element of each said color light-emit by predetermined | prescribed light emission amount ratio, when the field brightness | luminance measured by the said brightness | luminance measurement means is smaller than predetermined value, The illumination device for photographing according to any one of the above.   The control means corrects the light emission amount ratio until the difference between the first information and the second information converges within the predetermined range, and the light emitting elements of the respective colors at the corrected light emission amount ratio. The illumination device for photographing according to any one of claims 1 to 4, wherein the light emitting operation is repeated.   The said control means makes the light emitting element of each said color light-emit with a specific light emission amount ratio, when the said difference does not converge in the said predetermined range even if it performs the said correction | amendment operation | movement a predetermined number of times. The illuminating device for photography described in 1.

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