JP2007206405A - Auxiliary light irradiation device for photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary light irradiation device for photographing apparatus, wherein high quality image information depending on photographing conditions can be obtained without an increase in cost and size. <P>SOLUTION: The liquid crystal panel 60 is disposed on the optical path of an auxiliary light emitted by the single light source of a strobe section 44 toward a subject. The liquid crystal panel 60 is configured such that an amount of transmission light can be altered according to each pixel of predetermined resolving power. Photographing conditions are obtained by a CPU 40. The liquid crystal panel 60 is controlled via a liquid crystal control section 62 so that a transmitting state is switched according to the the photographing conditions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an auxiliary light irradiation device for an imaging device, and more particularly, to an auxiliary light irradiation device for an imaging device that adjusts the auxiliary light for the imaging device using a liquid crystal panel.

  In recent years, with the increase in resolution of solid-state imaging devices such as CCD (Charge Coupled Device) area sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, digital electronic still cameras, digital video cameras, mobile phones, PDAs (Personal Digital Assistants) , Portable information terminals) and other information devices having a photographing function are rapidly increasing. Information devices having the above photographing functions are collectively referred to as a digital camera.

  By the way, many of such photographing apparatuses such as digital cameras and silver halide photography cameras have a built-in strobe to cope with a case where the subject is dark, and this kind of photographing apparatus has a suitable amount of light emission of the strobe. Various ingenuity has been applied to adjust (dimming) things.

  As this type of technology, Patent Document 1 is equipped with a strobe device that illuminates a subject and shoots close to the subject for the purpose of obtaining an appropriate amount of subject light by strobe illumination during macro photography. In a camera with a strobe having a macro shooting function, a variable filter that is inserted in an irradiation light path of a light emitting unit of the strobe device and that can limit and adjust a transmitted light amount, and at least at the time of shooting by the macro shooting function, a transmitted light amount of the variable filter A technique is disclosed that includes filter control means for controlling and variably controlling the amount of light applied to the subject.

  Patent Document 2 discloses a reflecting surface that covers the back and sides of a lamp, a lamp power source connected to the lamp, and a lamp for the purpose of eliminating the trouble of adjusting the irradiation range of the light (corresponding to the strobe). In the illuminating device having the above, a technology is disclosed that includes a lamp, a liquid crystal light control sheet covering the front of the reflecting surface, and a voltage source connected to the transparent conductive layers on both surfaces of the sheet.

Furthermore, Patent Document 3 discloses that first and second strobe lights having different color temperatures can be emitted for the purpose of obtaining a natural color image without providing a white balance circuit and a vertical edge extraction circuit. A light emitting means having a light emitting tube; a monochrome liquid crystal filter disposed in front of the first and second light emitting tubes for controlling the amount of transmitted light; a color measuring means for detecting a color temperature of ambient light; and the color temperature. The color temperature of the strobe light is changed by controlling the density of the monochrome liquid crystal filter in accordance with the control so that the color temperature of the light illuminating the subject is substantially equal to the spectral sensitivity design value of the image sensor. And a technique comprising the means.
Japanese Patent Laid-Open No. 2004-102086 JP 7-209703 A JP 7-168261 A

  By the way, since various shooting conditions exist when shooting with the shooting device, shooting in a state corresponding to the shooting conditions is indispensable for obtaining high-quality image information.

  However, the techniques disclosed in Patent Document 1 and Patent Document 2 cannot perform shooting according to shooting conditions, and thus cannot obtain high-quality image information according to shooting conditions. was there.

  On the other hand, although the technique disclosed in Patent Document 3 can perform shooting according to the color temperature of the ambient light, it requires a plurality of light sources and liquid crystal filters. There has been a problem of increasing the size.

  The present invention has been made to solve the above-described problems, and provides an auxiliary light irradiation device for a photographing apparatus that can obtain high-quality image information according to photographing conditions without causing an increase in cost and size. The purpose is to provide.

  In order to achieve the above object, an auxiliary light irradiation device for a photographing apparatus according to the present invention includes a single light source that irradiates photographing auxiliary light toward a subject, and an optical path from the light source to the subject of the photographing auxiliary light. A liquid crystal panel configured to change the amount of transmitted light for each pixel having a predetermined resolution, an acquisition unit for acquiring imaging conditions, and the transmission state of the imaging auxiliary light is switched according to the imaging conditions. Control means for controlling the liquid crystal panel so as to be replaced.

  The auxiliary light irradiation device for an imaging device of the present invention is configured such that imaging auxiliary light is irradiated toward a subject by a single light source, and the transmitted light amount can be changed for each pixel having a predetermined resolution. The liquid crystal panel is provided on the optical path from the light source to the subject of the photographing auxiliary light. The light source includes any light emitting element capable of irradiating photographing auxiliary light such as a xenon tube or an LED (light emitting diode).

  Here, in the present invention, the imaging condition is acquired by the acquisition unit, and the liquid crystal panel is controlled by the control unit so that the transmission state of the imaging auxiliary light is switched according to the imaging condition.

  As described above, according to the auxiliary light irradiation device for an imaging device of the present invention, the imaging condition is acquired, and the imaging auxiliary light is irradiated toward the subject so that the transmission state is switched according to the imaging condition. Since the liquid crystal panel provided on the optical path to the subject of the photographing auxiliary light by the light source and configured to change the transmitted light amount for each pixel with a predetermined resolution is controlled. It is possible to obtain high-quality image information according to the shooting conditions without incurring the increase in image quality.

  In the present invention, the shooting condition is the distance to the subject, and the control means controls the liquid crystal panel so that the amount of transmitted light is small and uniform in macro shooting compared to normal shooting. The liquid crystal panel may be controlled so that a desired light amount is obtained at the subject position during normal photographing.

  In the present invention, the photographing condition may be a luminance distribution of the photographing auxiliary light, and the control unit may control the liquid crystal panel so that the luminance distribution of the photographing auxiliary light is uniform.

  In the present invention, the liquid crystal panel is a color liquid crystal panel, the shooting condition is a preset white balance, and the control means is a white balance in which a white balance of a subject image obtained by shooting is set in advance. The color liquid crystal panel may be controlled so as to be balanced.

  According to the present invention, the liquid crystal panel is a color liquid crystal panel, the shooting condition is a preset color tone, and the control means is a color tone of a subject image obtained by shooting, which is the preset color tone. As described above, the color liquid crystal panel may be controlled.

  In the present invention, the liquid crystal panel is a color liquid crystal panel, the photographing condition is a unique region of a subject image obtained by photographing, and the control unit detects the unique region from the subject image, The color liquid crystal panel may be controlled so that the color of the part corresponding to the region is different from the color of the part corresponding to the other region.

  In particular, in the present invention, the unique region may be a human face region.

  According to the present invention, the photographing auxiliary light reaches the subject by the single light source that shoots the photographing auxiliary light toward the subject so that the photographing condition is acquired and the transmission state is switched according to the photographing condition. Controls the liquid crystal panel that is provided on the optical path and can change the amount of transmitted light for each pixel with a predetermined resolution. Therefore, high quality according to the shooting conditions without increasing cost and size. The effect that it is possible to obtain accurate image information is obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a digital electronic still camera (hereinafter referred to as “digital camera”) that captures a still image will be described.

[First Embodiment]
First, an external configuration of the digital camera 10 according to the present embodiment will be described with reference to FIG.

  In front of the digital camera 10, a lens 21 for forming a subject image, a strobe unit 44 for emitting light (shooting auxiliary light) to irradiate the subject when necessary, and a composition of the subject to be photographed are determined. And a finder 20 used for the purpose. Further, on the upper surface of the digital camera 10, a release switch (so-called shutter) 56A, a power switch 56B, and a mode changeover switch 56C that are pressed when performing shooting are provided.

  Note that the release switch 56A of the digital camera 10 according to the present embodiment is pressed down to an intermediate position (hereinafter referred to as “half-pressed state”) and to a final pressed position beyond the intermediate position. A two-stage pressing operation of a state (hereinafter referred to as a “fully pressed state”) can be detected.

  In the digital camera 10, the release switch 56A is pressed halfway to activate the AE (Automatic Exposure) function and set the exposure state (shutter speed, aperture state), and then AF (Auto Focus). , Automatic focusing) function is performed to control focusing, and then exposure (photographing) is performed when the button is fully pressed.

  The mode changeover switch 56C is rotated when setting to any one of a shooting mode that is a mode for shooting and a playback mode that is a mode for playing back a subject image on the LCD 38 described later.

  On the other hand, on the back surface of the digital camera 10, an eyepiece of the finder 20, a liquid crystal display (hereinafter referred to as “LCD”) 38 for displaying a photographed subject image, a menu screen, and the like, and a cross cursor switch 56D. And are provided. The cross-cursor switch 56D includes four arrow keys that indicate four moving directions of up, down, left, and right in the display area of the LCD 38.

  Furthermore, on the back of the digital camera 10, a menu switch that is pressed when displaying the menu screen on the LCD 38, a determination switch that is pressed when confirming the operation content up to that point, and the previous operation content are displayed. And a cancel switch that is pressed when canceling.

  Next, with reference to FIG. 2, the configuration of the main part of the electrical system of the digital camera 10 according to the present embodiment will be described.

  The digital camera 10 includes an optical unit 22 including the lens 21 described above, a charge coupled device (hereinafter referred to as “CCD”) 24 disposed behind the optical axis of the lens 21, and an input analog. And an analog signal processing unit 26 that performs various analog signal processing on the signal.

  The digital camera 10 also performs an analog / digital converter (hereinafter referred to as “ADC”) 28 that converts an input analog signal into digital data, and performs various digital signal processing on the input digital data. And a digital signal processing unit 30.

  The digital signal processing unit 30 has a built-in line buffer having a predetermined capacity, and also performs control to directly store the input digital data in a predetermined area of the memory 48 described later.

  The output terminal of the CCD 24 is connected to the input terminal of the analog signal processing unit 26, the output terminal of the analog signal processing unit 26 is connected to the input terminal of the ADC 28, and the output terminal of the ADC 28 is connected to the input terminal of the digital signal processing unit 30. . Accordingly, the analog signal indicating the subject image output from the CCD 24 is subjected to predetermined analog signal processing by the analog signal processing unit 26, converted into digital image data by the ADC 28, and then input to the digital signal processing unit 30.

  On the other hand, the digital camera 10 generates a signal for displaying a subject image, a menu screen or the like on the LCD 38 and supplies the signal to the LCD 38, and a CPU (Central Processing Unit) 40 that controls the operation of the entire digital camera 10. A memory 48 that temporarily stores digital image data obtained by photographing, and a memory interface 46 that controls access to the memory 48 are included.

  Further, the digital camera 10 includes an external memory interface 50 for enabling the portable memory card 52 to be accessed by the digital camera 10, and a compression / decompression processing circuit 54 for performing compression processing and decompression processing on the digital image data. It is configured to include.

  In the digital camera 10 according to the present embodiment, a flash memory is used as the memory 48 and a smart media (Smart Media (registered trademark)) is used as the memory card 52.

  The digital signal processing unit 30, the LCD interface 36, the CPU 40, the memory interface 46, the external memory interface 50, and the compression / decompression processing circuit 54 are connected to each other via a system bus BUS. Therefore, the CPU 40 controls the operation of the digital signal processing unit 30 and the compression / decompression processing circuit 54, displays various information via the LCD interface 36 to the LCD 38, and the memory interface 46 or the external memory interface to the memory 48 and the memory card 52. 50 can be accessed each.

  On the other hand, the digital camera 10 includes a timing generator 32 that mainly generates a timing signal for driving the CCD 24 and supplies the timing signal to the CCD 24, and the driving of the CCD 24 is controlled by the CPU 40 via the timing generator 32.

  Further, the digital camera 10 is provided with a motor drive unit 34, and driving of a focus adjustment motor, a zoom motor, and an aperture drive motor (not shown) provided in the optical unit 22 is also controlled by the CPU 40 via the motor drive unit 34. The

  In other words, the lens 21 according to the present embodiment has a plurality of lenses, is configured as a zoom lens that can change (magnify) the focal length, and includes a lens driving mechanism (not shown). The lens drive mechanism includes the focus adjustment motor, the zoom motor, and the aperture drive motor, and these motors are each driven by a drive signal supplied from the motor drive unit 34 under the control of the CPU 40.

  Further, various switches such as the release switch 56A, the power switch 56B, the mode switch 56C, the cross cursor switch 56D, and the menu switch (generically referred to as “operation unit 56” in the figure) are connected to the CPU 40. The CPU 40 can always grasp the operation state with respect to the operation unit 56.

  In addition, the digital camera 10 is interposed between the strobe unit 44 and the CPU 40, and has power for causing a light source 44 </ b> A (see FIG. 3) described later provided in the strobe unit 44 to emit light under the control of the CPU 40. A charging unit 42 for charging is provided. Further, the strobe unit 44 is also connected to the CPU 40, and the light emission of the light source 44 </ b> A of the strobe unit 44 is controlled by the CPU 40.

  On the other hand, the strobe unit 44 according to the present embodiment is provided with a monochrome liquid crystal panel 60 configured so that the amount of transmitted light can be changed for each pixel having a predetermined resolution, and between the liquid crystal panel 60 and the CPU 40. A liquid crystal control unit 62 interposed therebetween is provided, and the amount of transmitted light by the liquid crystal panel 60 is controlled by the CPU 40 via the liquid crystal control unit 62.

  Next, the configuration of the flash unit 44 will be described with reference to FIG.

  As shown in the figure, the strobe unit 44 according to the present embodiment includes a single light source 44A composed of a xenon tube having a role of irradiating light (photographing auxiliary light) to a subject, and the light source 44A. And a reflecting plate 44B having a role of a reflector for condensing the photographing auxiliary light emitted from the projector.

  The reflection plate 44B according to the present embodiment has a semi-elliptical shape in cross section in which the opening (edge portion) faces the front of the digital camera 10, and the light source 44A is provided at the deepest portion of the inner surface of the reflection plate 44B. Yes. Therefore, the photographing auxiliary light emitted from the light source 44A is emitted toward the subject in a state in which the light reflected by the reflecting plate 44B is included.

  On the other hand, the liquid crystal panel 60 described above is provided in the opening of the reflection plate 44B, and the photographing auxiliary light emitted from the light source 44A is transmitted through the liquid crystal panel 60 including the light reflected by the reflection plate 44B. Has been.

  As shown in the figure, the liquid crystal panel 60 according to the present embodiment is provided with a liquid crystal layer 60A at the center thereof. A front electrode 60B and a polarizing plate 60D are provided on one side of the liquid crystal layer 60A, and a back electrode 60C and a polarizing plate 60E are provided on the other side of the liquid crystal layer 60A in a stacked state. In addition, the liquid crystal panel 60 is further laminated with an alignment curtain, a glass substrate, and the like. However, since these structures are conventionally known, further description of the liquid crystal panel 60 is omitted here.

  The digital camera 10 is equipped with a macro shooting mode that can suitably perform close-up shooting. In the digital camera 10 according to the present embodiment, the setting of the macro shooting mode can be performed by operating the operation unit 56. However, the present invention is not limited to this, and a dedicated switch for setting the macro shooting mode is provided in advance, and the mode is set by operating the switch. Needless to say, you can.

  Next, an overall operation at the time of shooting of the digital camera 10 according to the present embodiment will be briefly described.

  First, the CCD 24 performs imaging through the optical unit 22 and sequentially outputs analog signals for R (red), G (green), and B (blue) indicating the subject image to the analog signal processing unit 26. The analog signal processing unit 26 performs analog signal processing such as correlated double sampling processing on the analog signal input from the CCD 24 and sequentially outputs the analog signal to the ADC 28.

  The ADC 28 converts the R, G, and B analog signals input from the analog signal processing unit 26 into 12-bit R, G, and B signals (digital image data) and sequentially outputs them to the digital signal processing unit 30. To do. The digital signal processing unit 30 accumulates digital image data sequentially input from the ADC 28 in a built-in line buffer and temporarily stores the digital image data directly in a predetermined area of the memory 48.

  The digital image data stored in a predetermined area of the memory 48 is read out by the digital signal processing unit 30 according to the control by the CPU 40, and is subjected to white gain by applying a digital gain for each of R, G, and B according to a predetermined physical quantity. In addition to performing balance adjustment, gamma processing and sharpness processing are performed to generate 8-bit digital image data.

  The digital signal processing unit 30 performs YC signal processing on the generated 8-bit digital image data to generate a luminance signal Y and chroma signals Cr and Cb (hereinafter referred to as “YC signal”), and the YC signal. Are stored in an area different from the predetermined area of the memory 48.

  The LCD 38 is configured to display a moving image (through image) obtained by continuous imaging by the CCD 24 and can be used as a finder. When the LCD 38 is used as a finder, the LCD 38 is generated. The YC signals thus output are sequentially output to the LCD 38 via the LCD interface 36. As a result, a through image is displayed on the LCD 38.

  Here, at the timing when the release switch 56A is half pressed by the user, after the AE function is activated and the exposure state is set as described above, the AF function is activated and the focus control is performed, and then the fully pressed state is continued. The YC signal stored in the memory 48 at that time is compressed in a predetermined compression format (in this embodiment, JPEG format) by the compression / decompression processing circuit 54 and then the external memory interface 50 is To the memory card 52 as an electronic file (image file).

  Incidentally, the digital camera 10 according to the present embodiment is equipped with a function of controlling the liquid crystal panel 60 so that the luminance distribution of the photographing auxiliary light by the strobe unit 44 is uniform. And in the digital camera 10, the adjustment data acquisition process which acquires the adjustment data mentioned later used when performing the said function at a predetermined timing is performed. In the digital camera 10 according to the present embodiment, the timing at which execution of the adjustment data acquisition process is instructed on the menu screen by the user is applied as the predetermined timing. However, the present invention is not limited to this. .

  Next, the operation of the digital camera 10 when executing the adjustment data acquisition process will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of the adjustment data acquisition processing program executed by the CPU 40 of the digital camera 10 at this time, and the program is stored in a predetermined area of the memory 48 in advance.

  First, in step 100, the light source 44A of the strobe unit 44 is set to forcibly emit light at the time of shooting, and in the next step 102, the liquid crystal control unit is set so that the liquid crystal panel 60 is completely transmissive for all pixels. 62 is controlled.

  Here, after instructing the execution of the adjustment data acquisition process, the user prepares only a panel that is prepared in advance for acquisition of adjustment data and has a uniform surface and a uniform color (here, gray). Take a picture. The predetermined color is not limited to gray but may be black, white, or the like.

  Therefore, in the next step 104, the user waits for shooting, and in the next step 106, the digital image data obtained by the shooting is read from the memory card 52, and further read in the next step 108. After the luminance distribution information (adjustment data) is derived based on the digital image data and stored in a predetermined area of the memory 48, the adjustment data acquisition processing program is terminated. In the adjustment data acquisition processing program according to the present embodiment, the luminance distribution information is directly applied to the value of the luminance signal Y for each pixel in the read digital image data.

  Next, with reference to FIG. 5, the operation of the digital camera 10 when the light emission control for the light source 44A of the strobe unit 44 is executed will be described. FIG. 5 is a flowchart showing a processing flow of a light emission control processing program executed by the CPU 40 of the digital camera 10 when shooting is performed with the light source 44A of the flash unit 44 being lit, and the program is also stored in the memory. It is stored in advance in 48 predetermined areas.

  First, in step 200, it is determined whether or not the macro shooting mode is set. If the determination is affirmative, the process proceeds to step 202, and the macro shooting mode sets the emission luminance of the light source 44A of the flash unit 44. It is derived so as to be lower in luminance and uniform than in normal shooting that is not performed, and then the process proceeds to step 208 described later. Note that in the light emission control processing program according to the present embodiment, the derivation of the light emission luminance is determined in advance as a memory that can avoid the occurrence of whiteout in the captured image due to the short distance to the subject. This is done by reading the light emission luminance stored in 48.

  On the other hand, if the determination in step 200 is negative, the process proceeds to step 204, and the distance to the subject and the brightness of the subject are derived. In the light emission control processing program according to the present embodiment, the distance to the subject is derived by applying the distance to the subject that is uniquely specified based on the lens position immediately after execution of the AF function. However, the present invention is not limited to this, and the digital camera 10 may be provided with a distance measuring sensor that measures the distance to the subject, and may be derived from the distance measuring sensor. In the light emission control processing program according to the present embodiment, the brightness of the subject is derived, the digital image data stored in the memory 48 at that time is read, and the average value of the luminance signal Y of the digital image data is read. However, the present invention is not limited to this, and the digital camera 10 may be provided with a photometric sensor that detects ambient brightness and may be derived by using the photometric sensor.

  In the next step 206, the light emission luminance of the light source 44A of the strobe unit 44 is derived so that the distance to the subject derived by the processing of step 204 is shorter and becomes a mesh shape. In the light emission control processing program according to the present embodiment, the emission luminance can be derived by avoiding the occurrence of whiteout in the photographed image due to the short distance to the subject and the distance to the subject. The occurrence of underexposure due to a long period of time can be avoided, and the brightness of the subject and the distance to the subject stored in the memory 48, which is determined in advance as a luminance distribution having a mesh shape, This is done by reading out the brightness of the subject and the brightness of the subject derived by the processing of step 204 from the information indicating the relationship with the emission brightness of the corresponding light source 44A.

  In the next step 208, the luminance distribution information stored by the adjustment data acquisition processing program is read from the memory 48, and in the next step 210, the photographing auxiliary light transmitted through the liquid crystal panel 60 is read based on the read luminance distribution information. The transmission state of the liquid crystal panel 60 is controlled via the liquid crystal control unit 62 and the light source 44A of the strobe unit 44 is controlled so that the luminance distribution can be made uniform with the light emission luminance derived by the processing of step 202 or step 206. After controlling the light emission brightness, the light emission control processing program is terminated.

  FIG. 6 schematically shows an example of a state in which the transmission state of the liquid crystal panel 60 is switched according to the distance to the subject. As shown in the figure, when the macro shooting mode is set by executing this light emission control processing program and the distance to the subject is close, the transmittance of the liquid crystal panel 60 is lowered overall. (FIG. 6A) As a result, it is possible to prevent the occurrence of whiteout in the photographed image. On the other hand, during normal photography in which the macro photography mode is not set, the entire liquid crystal panel 60 increases as the distance to the subject increases. As a result, it is possible to prevent the occurrence of underexposure. In FIG. 6A, the density of the liquid crystal panel 60 is uniform throughout, and in FIG. 6B, the density of the liquid crystal panel 60 is uniform for each of the bright part and the dark part. Needless to say, the distribution state corresponds to the luminance distribution indicated by the luminance distribution information.

  As described above in detail, in the present embodiment, a single light source (here, which captures shooting conditions) and irradiates shooting auxiliary light toward the subject so that the transmission state is switched according to the shooting conditions. Then, a liquid crystal panel (here, the liquid crystal panel 60) provided on the optical path from the light source 44A) to the subject to the subject and configured so that the amount of transmitted light can be changed for each pixel having a predetermined resolution. Since the control is performed, it is possible to obtain high-quality image information corresponding to the photographing conditions without causing an increase in cost and size.

  Further, in the present embodiment, the distance to the subject is applied as the photographing condition, and the liquid crystal panel is controlled so that the amount of transmitted light is small and uniform during macro photography compared to normal photography, Since the liquid crystal panel is controlled so that a desired light amount is obtained at the subject position during normal photographing, it is possible to prevent occurrence of overexposure and underexposure with respect to the photographed image, thereby obtaining high quality image information. be able to.

  Further, in the present embodiment, the luminance distribution of the auxiliary photographing light is also applied as the photographing condition, and the liquid crystal panel is controlled so that the luminance distribution of the auxiliary photographing light is uniform. High quality image information indicating an image can be obtained.

  In the present embodiment, the case where a panel prepared in advance at the time of executing the adjustment data acquisition process has been described. However, the present invention is not limited to this, and for example, the surface is uniform in density and uniform. It is also possible to take an image of other subjects such as walls, ceilings, floors, etc., which have a predetermined color. In this case, since it is not necessary to prepare the panel, the present invention can be realized at low cost.

  In the present embodiment, the case where adjustment data acquisition processing is executed when an execution instruction is input by a user has been described. However, the present invention is not limited to this, and for example, a captured image may be captured. Execute adjustment data acquisition processing at other timings, such as a form in which the luminance distribution information obtained based on image data representing the captured image is stored when the color is uniformly a predetermined color with a uniform density It can also be set as the form to do.

[Second Embodiment]
In the first embodiment, an example in which a monochrome panel is applied as the liquid crystal panel of the present invention has been described. However, in the second embodiment, a color liquid crystal panel is applied as the liquid crystal panel of the present invention. The example of the case where it does is demonstrated. Note that the configuration of the digital camera 10 according to the second embodiment is the same as that of the digital camera 10 according to the first embodiment except for the configuration of the strobe unit. Only the configuration of the strobe unit 44 ′ will be described. Here, the same components in FIG. 7 as those in FIG. 3 are denoted by the same reference numerals as those in FIG.

  As shown in FIG. 7, the strobe unit 44 ′ according to the second embodiment is applied with a color liquid crystal panel 60 ′ instead of the liquid crystal panel 60 with respect to the strobe unit 44 according to the first embodiment. Only the differences are different.

  In the color liquid crystal panel 60 ', a color filter 60F composed of the three primary colors R, G, and B is laminated between the surface electrode 60B and the polarizing plate 60D. Since the configuration of the color liquid crystal panel is conventionally known, further description of the color liquid crystal panel 60 'is omitted here. Needless to say, the liquid crystal control unit 62 of the digital camera 10 according to the second embodiment is configured to be able to control the operating state of the color liquid crystal panel 60 '.

  By the way, in the digital camera 10 according to the second embodiment, when shooting is performed with the light source 44A of the flash unit 44 ′ being lit, the flash unit 44 ′ is set in a preset shooting assist light irradiation mode. The function which can operate is installed.

  Here, in the digital camera 10 according to the present embodiment, as the photographing auxiliary light irradiation mode, a desired white balance in which the white balance of the photographed image is set in advance (here, according to a preset desired light source type). White balance adjustment mode that illuminates the shooting auxiliary light so as to achieve white balance, and a desired color tone in which the color tone of the shot image is set in advance (here, a preset cold color tone, warm color tone, and sepia tone) The special effect mode for irradiating the photographing auxiliary light so as to achieve any color tone, and the color of the portion corresponding to a predetermined specific region (here, the human face region) of the photographed image is the other region Three types of spotlight modes for irradiating photographing auxiliary light are prepared in advance so as to be different from the color corresponding to the.

  In the digital camera 10 according to the present embodiment, each mode of the white balance adjustment mode, special effect mode, and spotlight mode, and the desired light source type and special effect mode when the white balance adjustment mode is set. The desired color tone is set by setting on the menu screen, but the present invention is not limited to this, and a dedicated switch for setting these information is provided in advance. Needless to say, the mode can be set by operating the switch.

  Next, the operation of the digital camera 10 when the light emission control for the light source 44A of the strobe unit 44 'is executed will be described with reference to FIG. Note that FIG. 8 shows a flow of processing of a light emission control processing program executed by the CPU 40 of the digital camera 10 according to the second embodiment when shooting is performed with the light source 44A of the flash unit 44 ′ being turned on. The program is stored in a predetermined area of the memory 48 in advance.

  First, in step 300, it is determined whether the white balance adjustment mode is set. If the determination is affirmative, the process proceeds to step 302.

  In step 302, the light source type in the shooting environment is specified based on the digital image data stored in the memory 48 at this time, and in the next step 304, the desired light source type preset by the user is specified. To do.

  In the next step 306, the gain for white balance adjustment determined in advance corresponding to the light source type specified by the processing in step 302 and the light source type specified in advance in the processing in step 304 are determined. A difference from the gain for white balance adjustment is derived for each of R, G, and B, and the color liquid crystal panel 60 is compensated for in the next step 308 so that the derived difference is compensated (the difference becomes 0 (zero)). The transmission state of each of R, G, and B is controlled via the liquid crystal control unit 62, and then the process proceeds to step 324 described later.

  On the other hand, if the determination in step 300 is negative, the process proceeds to step 310, and it is determined whether the special effect mode is set. If the determination is affirmative, the process proceeds to step 312.

  In step 312, the desired color tone preset by the user is specified, and in the next step 314, the transmitted light amounts of R, G, and B are set so that the color tone of the photographing auxiliary light that has been transmitted becomes the specified color tone. The color liquid crystal panel 60 ′ is controlled via the liquid crystal control unit 62 so that the ratio is set, and then the process proceeds to step 324 described later. In the digital camera 10 according to the present embodiment, information indicating the above ratio is stored in advance in the memory 48 for each color tone of the cold color tone, the warm color tone, and the sepia tone, and corresponds to the specified color tone. The ratio is set by reading the ratio from the memory 48 and applying it, but it goes without saying that the ratio is not limited to this.

  On the other hand, if the determination in step 310 is negative, the process proceeds to step 316, and it is determined whether the spotlight mode is set. If the determination is affirmative, the process proceeds to step 318.

  In step 318, a human face region is detected based on the digital image data stored in the memory 48 at this time. In the light emission control processing program according to the present embodiment, the detection of the face area is performed by detecting a skin color area in the subject image indicated by the digital image data, and an area having a curve at the periphery. However, the present invention is not limited to this, and it goes without saying that other known face detection techniques can be applied.

  In the next step 320, the color liquid crystal panel 60 ′ is liquid crystal so that the color of the transmitted light in the part corresponding to the region detected by the processing in step 318 is different from the color of the transmitted light in the part corresponding to the other region. Control is performed via the control unit 62, and then the process proceeds to step 324 described later. In the emission control processing program according to the present embodiment, the color of the transmitted light corresponding to the detected area is pink, and the color of the transmitted light corresponding to the other area is blue. Not limited to this, the color of the transmitted light corresponding to the detected area is set to the color of the light emitted from the light source 44A (that is, the corresponding part of the color liquid crystal panel 60 ′ is in a completely transmissive state). Needless to say, the color of the transmitted light in the part corresponding to the other region can be any color different from the color of the emitted light.

  On the other hand, if a negative determination is made in step 316, the process proceeds to step 322, and the liquid crystal panel 60 ′ is placed via the liquid crystal control unit 62 so as to be in a normal state (here, all pixels are completely transmissive). Then, control is passed to step 324.

  In step 324, control is performed so that the light source 44A of the strobe unit 44 emits light with a luminance corresponding to the brightness of the subject, and then the main light emission control processing program is terminated.

  When the user sets the white balance adjustment mode by executing the light emission control processing program, the light source type of the shooting environment has a luminance distribution characteristic as shown in FIG. Even in the case of a lamp.), It is possible to obtain a captured image in a state of being captured under the light source type set by the user.

  On the other hand, when the special effect mode is set by the user, when the color tone set by the user is a cold color tone, for example, a blue component as shown in FIG. A photographed image having increased luminance distribution characteristics can be obtained, and when the color tone set by the user is a warm color tone, for example, the red component as shown in FIG. It is possible to obtain a photographed image having the brightness distribution characteristic.

  On the other hand, when the spotlight mode is set by the user, when the subject image is as shown in FIG. 11A, it corresponds to a human face region as shown in FIG. 11B as an example. As a result, the color liquid crystal panel 60 ′ is controlled so that the color of the transmitted light in the part to be transmitted is different from the color of the transmitted light in the part corresponding to the other region. As a result, as shown in FIG. A photographed image with only the face emphasized can be obtained.

  As described above in detail, in the present embodiment, a single light source (here, which captures shooting conditions) and irradiates shooting auxiliary light toward the subject so that the transmission state is switched according to the shooting conditions. In the liquid crystal panel (here, the color liquid crystal panel 60 ′) provided on the optical path from the light source 44A) to the subject to the subject and configured to change the amount of transmitted light for each pixel having a predetermined resolution. ) Is controlled, it is possible to obtain high-quality image information according to the photographing conditions without increasing the cost and size.

  In the present embodiment, a color liquid crystal panel is applied as the liquid crystal panel, and a white balance set in advance as the shooting condition is applied, and the white balance of the subject image obtained by shooting is set in advance. Since the color liquid crystal panel is controlled so as to achieve white balance, it is possible to obtain high-quality image information indicating a photographed image photographed under a desired light source type.

  In the present embodiment, the color liquid crystal panel is controlled so that the color tone set in advance as the shooting condition is also applied and the color tone of the subject image obtained by shooting becomes the color tone set in advance. High-quality image information indicating a photographed image having a desired color tone can be obtained.

  Further, in the present embodiment, a peculiar region of the subject image obtained by photographing is also applied as the photographing condition, the peculiar region is detected from the subject image, and the color of the part corresponding to the region is changed to another color. Since the color liquid crystal panel is controlled so as to be different from the color of the portion corresponding to the region, it is possible to obtain high-quality image information indicating a captured image in a state where only the image of the specific region is emphasized.

  In particular, in the present embodiment, since the human face area is applied as the unique area, it is possible to obtain high-quality image information indicating a captured image in a state where only the human face image is emphasized. it can.

  In the present embodiment, the case where the digital camera 10 is configured to be able to execute all the modes of the white balance adjustment mode, the special effect mode, and the spotlight mode has been described. However, the present invention is not limited to this. Instead, only one or two of these modes can be configured to be executable. Also in this case, the same effects as in the present embodiment can be obtained.

  In each of the above embodiments, a case where a xenon tube is applied as the light source of the present invention has been described. However, the present invention is not limited to this, and other light sources such as LEDs are applied. You can also. Also in this case, the same effects as those of the above embodiments can be obtained.

  In addition, the configuration (see FIGS. 1 to 3 and 7) of the digital camera 10 according to each of the above embodiments is an example, and it is needless to say that the configuration can be appropriately changed without departing from the gist of the present invention. .

  In addition, the processing flow of the various processing programs described in the above embodiments (see FIGS. 4, 5, and 8) is also an example, and the processing order of each step is within the scope of the present invention. Needless to say, it is possible to change the process, change the processing contents, delete unnecessary steps, add new steps, and the like.

  Further, although cases have been described with the above embodiments where the present invention is applied to a digital camera, it goes without saying that the present invention can be applied to any information device having a photographing function, such as a PDA or a mobile phone. Yes.

It is an external view which shows the external appearance of the digital camera which concerns on embodiment. It is a block diagram which shows the principal part structure of the electric system of the digital camera which concerns on embodiment. It is a cross-sectional side view which shows the structure of the flash part which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of the adjustment data acquisition process program which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of the light emission control processing program which concerns on 1st Embodiment. It is a schematic diagram which shows the example of a state in which the transmission state of a liquid crystal panel switches according to the distance to a to-be-photographed object by execution of the light emission control processing program which concerns on 1st Embodiment. It is a cross-sectional side view which shows the structure of the flash part which concerns on 2nd Embodiment. It is a flowchart which shows the flow of a process of the light emission control processing program which concerns on 2nd Embodiment. It is a graph with which it uses for description of the light emission control processing program which concerns on 2nd Embodiment. It is another graph with which it uses for description of the light emission control processing program which concerns on 2nd Embodiment. It is a schematic diagram with which it uses for description of the light emission control processing program which concerns on 2nd Embodiment.

Explanation of symbols

10 Digital camera 24 CCD
40 CPU (acquisition means, control means)
44, 44 'Strobe unit 44A Light source 48 Memory 60 Liquid crystal panel 60' Color liquid crystal panel

Claims (7)

A single light source that emits shooting assistance light toward the subject;
A liquid crystal panel provided on an optical path from the light source to the subject of the photographing auxiliary light and configured to change a transmitted light amount for each pixel having a predetermined resolution;
Acquisition means for acquiring shooting conditions;
Control means for controlling the liquid crystal panel so that the transmission state of the photographing auxiliary light is switched according to the photographing condition;
Auxiliary light irradiating device for photographing apparatus. The shooting condition is a distance to the subject,
The control means controls the liquid crystal panel so that the amount of transmitted light is small and uniform during macro photography compared to during normal photography, and the liquid crystal panel provides a desired light quantity at the subject position during normal photography. The auxiliary light irradiation device for an imaging device according to claim 1. The photographing condition is a luminance distribution of the photographing auxiliary light,
The auxiliary light irradiation device for a photographing apparatus according to claim 1, wherein the control unit controls the liquid crystal panel so that a luminance distribution of the photographing auxiliary light is uniform. The liquid crystal panel is a color liquid crystal panel,
The shooting condition is a preset white balance,
The auxiliary light irradiation device for a photographing apparatus according to claim 1, wherein the control means controls the color liquid crystal panel so that a white balance of a subject image obtained by photographing becomes the preset white balance. The liquid crystal panel is a color liquid crystal panel,
The shooting condition is a preset color tone,
The auxiliary light irradiation device for a photographing apparatus according to claim 1, wherein the control means controls the color liquid crystal panel so that a color tone of a subject image obtained by photographing becomes the preset color tone. The liquid crystal panel is a color liquid crystal panel,
The shooting condition is a unique area of a subject image obtained by shooting,
The control unit detects the peculiar area from the subject image, and controls the color liquid crystal panel so that a color of a part corresponding to the area is different from a color of a part corresponding to another area. Auxiliary light irradiation device for photographing apparatus. The auxiliary light irradiation device for a photographing apparatus according to claim 6, wherein the unique region is a region of a human face.