JP2009284079A - Camera system and image generating method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera system which suppresses power consumption for lighting in a live view mode, and produces the same color when an object is observed in the live view mode under illumination and when the object is imaged under illumination, and to provide an image generating method thereof. <P>SOLUTION: In a lighting unit 100, a lighting control circuit 111 switches a state of auxiliary light between a first lighting mode suitable for low luminance and a long-time lighting and a second lighting state suitable to high luminance and a short-time lighting different in color component from the first lighting state. In the camera system 1, a body control circuit 31 turns on the auxiliary light in the first lighting state for the live view mode and in the second lighting state when a photographic image is acquired. An image processing circuit 34 corrects colors of a display image illuminated in the first lighting state in the live view mode to have colors nearly the same as those of a photographic image illuminated in the second lighting state, based upon data stored in a memory 125. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a camera system having a camera having a live view function capable of electronically generating and observing an object scene, a lighting system capable of illuminating a subject during live view and photographing, and an image generation method therefor It is about.

  There is known a technique for illuminating a subject with an auxiliary illumination of an imaging device even when observing a subject before photographing.

However, since illumination during observation of the subject consumes a large amount of power, a technique for saving the power is essential. As a technique for saving power during object observation, a technique described in Patent Document 1 below is known. In the method described in Patent Document 1, a light emitting diode (LED) for illumination is driven by duty (DUTY) driving, and power is saved by lowering the duty ratio during object observation.
JP 2006-145877 A

  Incidentally, in recent years, the performance of light-emitting diodes (LEDs) has been improved, and it has come to be used as illumination or auxiliary illumination for imaging devices. In the case of a digital still camera, since it is necessary to faithfully reproduce colors, it is necessary to use an LED capable of emitting white light. In order to generate a white LED, a fluorescent material is applied to the reflecting portion using a blue LED, and the color of the blue LED is shifted to the red side to generate white (TYPE 1), or blue, green, red 3 There is a method (TYPE 2) in which a plurality of LEDs having different color components such as colors are used.

  These light emitting diodes can change the amount of light by an energization current, but color shift may occur when the amount of light is changed. In the case of the TYPE1 method described above, the emission wavelength distribution of the blue LED may be shifted, whereas in the TYPE2 method, all three colors are shifted. In the case of the TYPE2 method, the point at which the proportional relationship between the current and the amount of light emission is lost differs depending on the LED. Therefore, even when the current ratio is constant, the color shift may occur when a large current is applied to increase the amount of light. growing.

  When live view is activated, it is lit for a long time, so it is necessary to keep the drive current low, and at the time of shooting, as much light as possible is necessary from the viewpoint of maintaining good image quality. If this is attempted to be realized with an LED, a color shift between live view and shooting increases. In Patent Document 1, it is difficult to increase the amount of light, and it is difficult to achieve both power saving during live view and irradiation light amount during shooting.

  On the other hand, it is conceivable to use an LED or the like during live view and a flash light emitting element such as a xenon tube at the time of shooting. In this case, however, the colors of the LED and the flash light emitting element are not the same, and a color shift occurs.

  Also, as a problem in scenes where there is a lot of constant light, when irradiating with a different amount of light when actually shooting in live view and when observing, the ratio of constant light and irradiated light seen in live view is compared to when shooting. Different. In this case, it is difficult to reproduce the finally photographed color with a live view unless considering not only the color of the irradiation light but also the light quantity ratio with the steady light.

  Therefore, the present invention has been made in view of the above circumstances, and is photographed by irradiating illumination light and colors observed during live view when illuminating while suppressing power consumption of illumination during live view. It is an object of the present invention to provide a camera system that matches the color of the image and a method for generating the image.

  The present invention also provides a camera system capable of predicting and displaying in real time an image equivalent to the image at the time of shooting, even during live view in which the ratio of stationary light and irradiation light is different from that at the time of shooting, and image generation thereof It aims to provide a method.

  That is, the invention described in claim 1 includes a camera having a live view mode that continuously captures and displays subject images that can be interlocked with each other, and an illumination device that illuminates the subject with auxiliary light. In the camera system, the illuminating device is a first lighting state suitable for low brightness and long time, and high brightness and short time compared to the first lighting state. Illumination control means for switching to and lighting a second lighting state having a different color component from the first lighting state is provided, and at least one of the camera and the lighting device includes the first lighting state and the second lighting state. Storage means storing each illumination color component of each of the two lighting states, and the camera emits the auxiliary light in the first lighting state in the live view mode and in the second lighting state in capturing the captured image. Light Control means for controlling the color of the display image in the live view mode illuminated in the first lighting state, and the auxiliary light in the second lighting state based on the data stored in the storage means. And a photographed image correcting means for correcting the illumination photographed image so as to be substantially the same as the color of the illuminated photographed image.

  According to the first aspect of the present invention, there is no color difference due to the illumination light between the live view image and the photographed image even if the lighting is performed in different lighting states at the time of live view and photographing, and the color at the time of photographing is correct in real time. Observe in advance.

  According to a second aspect of the present invention, in the first aspect of the present invention, the lighting device further includes the lighting device at a rate of once per a plurality of frames in synchronization with an image capturing timing in the live view mode. The camera illuminates auxiliary light, and the camera includes a lighting instruction means for instructing the lighting device of a lighting state during live view, a display image of the live view mode acquired when the auxiliary light is turned on, and auxiliary light. And a live view display image generation unit that displays a live view mode display image acquired without lighting and an image predicted to be generated at the time of shooting based on the output of the storage unit as a live view image. It is characterized by that.

  According to the second aspect of the present invention, in the case of shooting by illuminating the auxiliary light, it is possible to display a display image at the time of live view substantially equivalent to the captured image even if there is steady light.

  The invention according to claim 3 is the invention according to claim 2, wherein the camera extracts an image component by illumination from the frame image with illumination of the auxiliary light and the frame image without illumination, Based on the output of the storage means, the illumination image at the time of shooting is predicted as a predicted image, and the image at the time of shooting is predicted and displayed by superimposing the predicted image on the image without illumination. .

  According to the third aspect of the invention, in the case of shooting with illumination of auxiliary light, even if there is steady light, the display image at the time of live view is almost equivalent to the captured image in real time more accurately. Can be displayed.

  According to a fourth aspect of the present invention, there is provided a photographic lens, an image sensor that captures an image of a subject that has passed through the photographic lens, display means that displays a subject image based on an output of the image sensor, and the subject The illumination device that illuminates the auxiliary light and the auxiliary light, the first lighting state suitable for low brightness and long time, and high brightness and short time suitable for the first lighting state. Illumination control means for switching to and lighting the second lighting state having a color component different from the first lighting state, and storage means for storing the lighting color components of the first lighting state and the second lighting state, respectively. And a control means for controlling to turn on the auxiliary light in the first lighting state in the live view mode for continuously capturing and displaying the subject image and in the second lighting state at the time of capturing the captured image. Illuminate in the first lighting state A captured image for correcting the color of the display image in the live view mode so as to be substantially the same as the color of the captured image illuminated with the auxiliary light in the second lighting state, based on the data stored in the storage unit And a correcting means.

  According to the fourth aspect of the present invention, there is no color difference due to illumination light between the live view image and the photographed image even if the illumination is performed in different lighting states at the time of live view and photographing, and the correct color at the time of photographing is obtained in real time. Observe in advance.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the illuminating device is configured to emit the auxiliary light at a rate of once per a plurality of frames in synchronization with an image capturing timing in the live view mode. In addition, the lighting instruction means for instructing the lighting device to indicate the lighting state during live view, the display image of the live view mode acquired with the auxiliary light turned on, and the auxiliary light without lighting. A live view mode display image, and live view display image generation means for displaying, as a live view image, an image predicted to be generated at the time of shooting based on the output of the storage means. .

  According to the fifth aspect of the present invention, in the case of taking a picture by illuminating the auxiliary light, it is possible to display the display image at the time of live view substantially equivalent to the taken picture even if there is constant light.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, an image component by illumination is extracted from the frame image with illumination of the auxiliary light and the frame image without illumination, and this is stored in the memory. Prediction display means for predicting an illumination image at the time of shooting as a predicted image based on the output of the means and predicting and displaying the image at the time of shooting by superimposing the prediction image on the image without illumination. Features.

  According to the sixth aspect of the present invention, in the case of shooting with illumination of auxiliary light, even when there is steady light, the display image at the time of live view is almost equivalent to the captured image in real time. Can be displayed.

  The invention described in claim 7 includes a camera having a live view mode that continuously captures and displays subject images that can be interlocked with each other, and an illumination device that illuminates the subject with auxiliary light. A method of generating an image of a system, wherein the auxiliary light is suitable for low luminance and a first lighting state illumination component suitable for a long time, and for a high brightness and a short time compared to the first lighting state. However, in the step of storing the illumination color component in the second lighting state, which is different from the first lighting state, and in the live view mode in which the subject image is continuously captured and displayed, low luminance and long time The step of illuminating the auxiliary light in a first lighting state suitable for the above, and the first lighting state suitable for high brightness and short time compared to the first lighting state at the time of capturing a captured image The auxiliary light in the second lighting state with different color components A step of illuminating and photographing the auxiliary light in the second lighting state based on the stored illumination color component for the color of the display image in the live view mode illuminated in the first lighting state And a step of correcting so as to be substantially equal to the color of the image.

  According to the seventh aspect of the present invention, there is no color difference due to illumination light between the live view image and the photographed image even if the lighting is performed in different lighting states at the time of live view and photographing, and the color at the time of photographing is correct in real time. Observe in advance.

  Advantageous Effects of Invention According to the present invention, a camera in which the color observed at the time of live view when illuminating the illumination and the color of the image taken by illuminating the illumination light match while suppressing the power consumption of the illumination at the time of live view. A system and an image generation method thereof can be provided.

  Further, according to the present invention, a camera system capable of predicting and displaying in real time an image equivalent to the image at the time of shooting, even during live view in which the ratio of stationary light and irradiation light is different from that at the time of shooting, and the camera system An image generation method can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1A and 1B show the appearance of a camera system according to a first embodiment of the present invention. FIG. 1A is a perspective view seen from the front side of the camera, and FIG. 1B is a perspective view seen from the rear side.

  The camera system 1 according to this embodiment includes a single-lens reflex digital still camera, and includes a camera body 10 and a lens unit 80 that can be attached to and detached from the camera body 10. Moreover, in this embodiment, the illumination unit 100 as an illumination device can be attached to and detached from the upper part of the camera body 10.

  The camera body 10 is provided with a power switch 11 and a release switch 12 on the top surface thereof, and a live view changeover switch 13, a cross button 14, and an LCD panel 15 on the back side. In addition, an eyepiece 17 is provided at the upper part on the back side of the camera body 10. Further, a hot shoe 18 as a contact portion is provided above the eyepiece 17.

  The power switch 11 is a switch for turning on / off the power of the camera in the camera system 1. The release switch 12 is for starting a shooting operation, and includes a two-stage switch including a first release switch and a second release switch. The first release switch is turned on to perform photographing preparation operations such as photometry processing and distance measurement processing, and the second release switch is turned on to perform exposure operation.

  The live view (LV) change-over switch 13 is a switch for switching between an object scene at the time of live view to be described later and an object scene at the time of using the optical viewfinder, and constitutes a switch instruction means together with a body control circuit 31 to be described later. ing. The cross button 14 is a selection switch for operating various functions of the camera together with a determination switch (not shown). The LCD panel 15 is display means for displaying an observation image during live view and a captured image after shooting.

  The eyepiece 17 is configured as a single-lens reflex optical viewfinder that forms an image of light that has passed through the photographing lens 81 in the lens unit 80. The hot shoe 18 provided on the upper portion of the optical viewfinder is an electrical contact portion for detachably attaching the illumination unit 100.

  In the lens unit 80, there is provided a photographing lens 81 for taking a light beam from a subject (not shown) and guiding it to an image pickup device to be described later.

  The illumination unit 100 is an illumination device for illuminating a subject when observing and photographing the subject.

  The lighting unit 100 includes a lighting head 105 and a lighting device body 106.

  The illumination head 105 is normally configured in the same direction as the shooting direction of the camera, but is configured to be able to change the direction vertically and horizontally. The illumination head 105 is, for example, a single chip as continuous illumination means that generates white light by reflecting light emitted from a flash light emitting unit 101 using a xenon tube and a blue light emitting diode (LED) to a phosphor. Type white light emitting diode (LED) 102 and a three-chip LED 103 as continuous illumination means that generates white light by mixing three primary colors of blue, green, and red.

  The lighting device main body 106 incorporates a control circuit (not shown). In addition, a shoe 107 as an electrical contact portion that can be engaged with the hot shoe 18 on the camera side when the illumination unit 100 is attached to the camera body 10 is provided below the illumination device body 106. The shoe 107 is exposed at the bottom, and when it is connected to the camera, it comes into contact with the shoe 107, and an electrical signal can be exchanged.

  FIG. 2 is a conceptual diagram showing an optical system of the camera system in the first embodiment.

  In FIG. 2, a quick return mirror 21 that can be rotated in the direction of the arrow M is located behind the photographic lens 81 in the camera body 10 on the optical axis, and behind this quick return mirror 21, for example, An image sensor 22 composed of a CCD or the like is provided. When the optical viewfinder is used, the quick return mirror 21 is in a position lowered on the photographing optical path as indicated by a solid line in the figure. On the other hand, at the time of shooting and at the time of live view, as shown by the two-dot chain line in the figure, it is raised to a position retracted from the shooting optical path.

  As described above, a live view mode is a mode in which a subject image obtained from the photographing lens 81 is continuously captured by the image sensor 22 and displayed on the LCD panel 15, and is configured by the image sensor 22, the LCD panel 15, and the like. This mechanism is an electronic live view display mechanism.

  A finder screen 23 and a pentaprism 24 are disposed above the quick return mirror 21. On the finder screen 23, the light passing through the taking lens 81 forms an image. The pentaprism 24 is for inverting the light beam reflected by the quick return mirror 21 up and down and left and right. In the vicinity of the pentaprism 24, an eyepiece 25 and a photometric element 27 are arranged. The eyepiece 25 enlarges the light transmitted through the photographing lens 81 and imaged on the finder screen 23 so that the observer can see the subject. The photometric element 27 is provided for measuring the brightness of the finder screen 23.

  As described above, the optical observation mechanism includes the quick return mirror 21, the finder screen 23, the pentaprism 24, the eyepiece 25, and the like. A mode in which the subject is observed by this optical observation mechanism is referred to as an optical finder mode.

  Due to the above configuration, observation of the object scene in the live view and observation of the object scene with the optical viewfinder cannot be performed at the same time, and either one is selected. Photometry with the photometry element 27 is possible when using the optical viewfinder, but photometry with the photometry element 27 is impossible when using live view. Therefore, when the live view is used, photometry is performed by the image sensor 22.

  FIG. 3 is a block diagram showing a schematic configuration of an electric circuit of the camera system in the first embodiment.

  The camera body 10 is provided with a body control circuit (hereinafter referred to as BCPU) 31 that performs various arithmetic controls and serves as a control means and a lighting instruction means, and controls each part inside the camera and performs communication. The lens unit 80 and the illumination unit 100 are controlled via the contacts J1 and J2.

  The BCPU 31 is connected to a photometric element 32, a mirror drive circuit 33, an image processing circuit 34, an image sensor driver 37, an LCD driver 39, various switches 42, and a memory 43.

  The photometric element 32 corresponds to the photometric element 27 in FIG. The mirror drive circuit 33 is a drive circuit for moving the quick return mirror 21 in the direction of arrow M in FIG. 2, and causes the mirror to move up and down by electric control. The image processing circuit 34 functions as a captured image correction unit and a live view display image generation unit for performing various types of image processing such as image signal compression and expansion, color adjustment and noise reduction, and data format conversion. Have The recording medium 35 is composed of a built-in memory in the camera or a removable memory card. An image processed by the image processing circuit 34 is written on the recording medium 35. Alternatively, the recorded image written on the recording medium 35 is read out and used by the BCPU 31 via the image processing circuit 34.

  The image sensor driver 37 drives the image sensor 38 to acquire a captured image, a live view image, and the like. Note that the image sensor 38 corresponds to the image sensor 22 shown in FIG. The LCD driver 39 displays an image generated for display by the image processing circuit 34 on the LCD panel 40 (corresponding to the LCD panel 15 in FIG. 1B).

  The various switches 42 are configured to include a power switch 11, a release switch 12, a live view changeover switch 13, a switch corresponding to the cross button 14 and the like shown in FIGS. The memory 43 is a storage means and stores data unique to the camera body. These data can be written and read by the BCPU 31.

  In the lens unit 80, a lens control circuit (hereinafter referred to as LCPU) 91 is provided. The LCPU 91 controls each part in the lens unit 80 and performs data communication with the BCPU 31 in the camera body 10 via the electrical contact J1. The LCPU 91 is connected to a memory 92 which is a storage means. The memory 92 stores lens-specific data and the like, and the stored data can be transmitted to the BCPU 31 in the camera body 10 via the LCPU 91.

  The lighting unit 100 is in electrical communication with the BCPU 31 in the camera body 10 and controls each part of the lighting unit 100 in accordance with instructions from the BCPU 31. An illumination control circuit (hereinafter referred to as FCPU) 111 serving as a lighting control means. have. The FCPU 111 is connected to a flash light emission drive control circuit 112, LED drivers 115 and 119, a colorimetric sensor processing circuit 124, and a memory 125.

  The flash light emission drive control circuit 112 drives a flash light emitting element 113 (corresponding to the flash light emitting unit 101 in FIGS. 1 and 2) which is a xenon (Xe) flash. The flash light emission drive control circuit 112 includes a one-chip type white LED 116 (the one-chip type white LED shown in FIGS. 1 and 2) that generates white light by reflecting the light emitted from the flash light emitting element 113 and the blue LED to the phosphor. 3 chip LED 120 (corresponding to 3 chip LED 103 in FIGS. 1 and 2) that generates white light by mixing three primary colors of blue, green, and red is connected.

  The LED driver 115 drives the white LED 116. Specifically, the white LED 116 is turned on and off, and the driving current of the LED chip is changed. The LED driver 119 drives the three-chip LED 120, and the current value can be set independently for each of the three chips of the LED.

  A colorimetric sensor 117 is provided in the vicinity of the one-chip type white LED 116 so that the light emission color component of the one-chip type white LED 116 can be detected. Further, a colorimetric sensor 121 is provided in the vicinity of the three-chip LED 120 so that a composite color component of the three-chip LED 120 that generates white light can be detected. Outputs of these colorimetric sensors 117 and 121 are converted into digital signals by the colorimetric sensor processing circuit 124 and output to the FCPU 111. From the colorimetric output of the LED, the FCPU 111 can grasp the color component in the initial state of each LED, and the data is also transmitted to the BCPU 31 via the communication contact J2.

  The memory 125 is a storage unit that stores color components corresponding to a plurality of driving states of each of the light emitting units (the flash light emitting element 113, the one-chip white LED 116, and the three-chip LED 120). Data can be sent to the BCPU 31 via the FCPU 111 and via the communication contact J2.

  FIG. 4 is an xy display chromaticity diagram (xy color chart).

In the figure, monochromatic light is represented on the line indicated by the surrounding solid line L ₀ . A curved line L ₁ represents a color line generated by the black body width. For example, the light emission of the xenon flash according to the present embodiment is almost the same color as the 5500K black body width irradiance, and is expressed in a place indicated as Xe in FIG. Point P ₀ is the white reference color of the 1-chip type white LED 116 and the 3-chip LED 120, and corresponds to a black body width of 5200K. However, this point P ₀ is a target color, and there may be a deviation from this point due to the LED driving conditions, temperature, solid differences of chips and phosphors, and the like.

Point P _R represents the color of the red LED of the three chip LEDs 120. Similarly point P _G is the green LED of the 3 chips LED120 color, the point P _B represents the color of the blue LED 3-chip LED. The 3-chip LED 120 can create a color inside a triangle indicated by a broken line in FIG. 4 by changing the light emission ratio of the three LEDs. In order to change the light emission ratio, the drive current ratio of each chip of the three-chip LED 120 may be changed. By combining them appropriately, and white to make the color of the point P _O. A point P _O ′ represents white corresponding to an optical viewfinder described later.

Point P ₁ represents the color when the rated maximum driving of the one-chip type white LED 116 is performed. In the case of this LED, the color has a drive current dependency and is slightly shifted in the red direction. This is mainly due to the temperature rise due to the drive current, and the light emission of the LED and the characteristics of the phosphor shift in the red direction.

Point P ₂ represents the case where all the chips of the three-chip LED 120 are driven at the rated maximum. In many cases, blue LEDs are more limited in driving current than other colors, and this embodiment is also like that. Therefore, when the maximum amount of light is desired, the color deviates from white.

  Next, with reference to the flowcharts of FIGS. 5 and 6, the operation of the camera according to the first embodiment at the time of shooting will be described.

  In this sequence, step S1 is a shooting standby state. This shooting standby state may be a live view or not a live view, and is in any state depending on the previous setting. In this shooting standby state, it is determined in step S2 whether or not the conditions are such that illumination is used when shooting with the camera. This is determined by the shooting mode of the camera, the setting of automatic lighting of low brightness / forced on / forced off, etc., the brightness of the field, and the like.

  Here, if it is determined that the condition is for operating the lighting unit 100, the process proceeds to step S3, and if not, the process proceeds to step S12 described later. In step S3, it is determined whether or not the current state is the live view mode. As a result, in the live view mode, the process proceeds to step S4. Otherwise, the process proceeds to step S11.

  Steps S4 and after are processes for controlling the turning on / off of the LEDs in conjunction with the live view image capture.

First, in step S4 in the live view mode, LED is lit in a state of white 1 (corresponding to the color point P _O). This white 1 state is a state in which the brightness is low and the current consumption of the LED is small, that is, the first lighting state with low brightness and suitable for long-time lighting. In live view, it is possible to display an image with low brightness brightly by image processing. Further, in the case of live view, since the power of related circuits increases, intermittent lighting is synchronized with the timing of integration of the live view image, and the drive current is also reduced.

  In step S5, live view integration of the image sensor 38 is started. Next, in step S6, proper integration is performed, and the integration in the image sensor 38 is stopped. When the integration is stopped, the LED is turned off in step S7. Thereafter, in step S8, the live view image is read out, and in the subsequent step S9, the image data is processed to generate a display image. In step S10, the image is displayed on the LCD panel 40, and the image update for one frame is completed.

On the other hand, if it is determined in step S3 that the current mode is not the live view mode, in step S11, the LED is continuously lit in a state corresponding to white 2 (corresponding to the color point _PO '). This is because when the subject is observed through the optical viewfinder, the sensitivity of the human eye is lower than that of the image sensor, and thus it is necessary to light up brightly. Therefore, it is driven with a larger current than in the live view. Moreover, it is set as continuous lighting so that a flickering feeling may not arise. This state is a second lighting state that has higher luminance than the first lighting state described above and is suitable for short-time lighting and has a different color component from the first lighting state.

  In step S12, whether or not the switch is operated is confirmed by the BCPU 31 detecting the state of each switch. If it is determined that there is no switch operation, the process proceeds to step S2. If it is determined that there is an operation, the process proceeds to step S13 and subsequent steps.

  In step S13, it is determined whether or not the operated switch is the live view changeover switch 13. Here, if it is the live view changeover switch 13, the process proceeds to step S16, and if not, the process proceeds to step S14.

  In step S16, it is determined whether or not the current state is a live view state. If the current state is not the live view state and the live view changeover switch 13 is operated, the process proceeds to step S17. In step S17, the camera is retracted from the photographing optical path with the quick return mirror 21 raised. At the same time, the focal plane shutter (not shown) located in front of the image sensor 38 is opened, and the image can be captured in real time. In step S18, the image-related circuit is set to an operating state corresponding to the live view. Thereafter, the process proceeds to step S1.

  On the other hand, when the live view change switch 13 is operated in the live view state in step S16, the process proceeds to step S19, and the operation of the related circuit in the live view state is stopped. In step S20, the quick return mirror 21 that has been retracted from the photographing optical path is lowered, and the focal plane shutter (not shown) that has been opened up to that point is closed. Thereafter, the process proceeds to step S1.

  In step S14, it is determined whether or not a release operation has been performed. If there is a release operation, the process proceeds to step S21. If there is no operation, the process proceeds to step S15.

  In step S21, it is determined whether or not the current state is a live view state. Here, if it is a live view, the process proceeds to step S22, the live view operation of the circuit system is stopped, and the LED is turned off. Thereafter, the process proceeds to step S23, the quick return mirror 21 is lowered, and the focal plane shutter (not shown) is closed. If it is determined in step S21 that the live view state is not set, steps S22 and S23 are skipped.

  In step S24, the quick return mirror 21 is mirrored, the image pickup device 38 is set in the integrated state, and a focal plane shutter (not shown) located in front of the image pickup device 38 is operated to perform image pickup. The flash light emitting element (xenon flash) 113 emits light in synchronization with the shutter opening. Further, the captured image is subjected to image processing and written to a recording medium. Thereafter, the process proceeds to step S1.

  In step S15, it is determined whether or not a switch (other switches) other than the live view switch 13 and the release switch 12 has been operated. If the switch has been operated, the process proceeds to step S25, and processing corresponding to the operated switch is performed. For example, when the cross button 14 is operated, the menu is opened or the setting is changed.

  After the process of step S25 is executed and when the switch is not operated in step S15, the process proceeds to step S1.

  FIG. 7 is a diagram showing an example of the drive current of the three-chip LED 120 in the first embodiment.

  As described above, the three-chip LED 120 is configured by three chips of R, G, and B, and (a), (b), and (c) indicate the drive current of each chip.

In driving conditions shown in FIGS. 7 (a) to produce a color of white. 1, the color of the state of the white 1 has a corresponds to the point P _O shown in FIG. Similarly, the white 2 color is generated under the driving conditions shown in FIG. 7B, and the color in the white 2 state corresponds to the point P ₀ ′ shown in FIG. Furthermore, the driving condition shown in FIG. 7C is a full light emission state, and the color in this state corresponds to the point P ₂ shown in FIG.

  As described above, in the driving state of FIG. 7A, for live view, intermittent light emission is performed with a small current and in synchronization with integration of the live view image. The driving state in FIG. 7B corresponds to the optical viewfinder. Therefore, the total current is larger than that in FIG. 7A, and the color is such that the color of the illumination light viewed through the optical viewfinder of the present embodiment is substantially the same as the color of the illumination light of the captured image. The color is slightly shifted. Also, it is illuminated with a slightly larger current value for viewing with the naked eye.

  FIG. 8 is a time chart for explaining the light emission state of the LED at the time of shooting standby.

  As shown in FIG. 8A, in the case of live view, illumination is started at a rate of once every two frames immediately before integration of the live view image, and illumination is stopped immediately after the end of integration.

  On the other hand, as shown in FIG. 8B, when it is not the live view, the light is continuously illuminated with a stronger light than that in the live view of FIG.

  Next, a live view image generation method according to the first embodiment will be described with reference to FIG. In the first embodiment, two frames of images with and without lighting are used to generate a display image.

  FIG. 9A is a diagram showing an example of a live view image captured without illumination from the camera side. In the figure, there is a wall illumination lamp 151, and the persons 152 and 153 are backlit and are darkened. If the light intensity of the portion indicated by the AA ′ line in this image is represented by a graph, it is as shown in FIG.

  FIG. 9C is a diagram illustrating an example of a live view image captured while being illuminated from the camera side. The dark area is slightly brighter due to the illumination from the camera side. However, since the illumination light is weaker than the steady light and weaker than the illumination at the time of photographing, the brightness is not sufficient. When the light intensity of the portion indicated by the line AA ′ in this image is represented by a graph, it is as shown in FIG. With respect to the graph shown in FIG. 9B described above, light is added to a portion indicated by hatching.

FIG. 9E is a diagram showing an example of a live view display image generated based on the images of FIG. 9A and FIG. 9C described above, and FIG. It is a graph which shows the light intensity of the part shown by the AA 'line in the image of. This is because if the ratio of the brightness of the illumination during live view and the illumination during shooting is X,
(Image in FIG. 9A) − (Image in FIG. 9C) * X + (Image in FIG. 9A)
Can be expressed as

  As described above, by predicting an image generated at the time of shooting from two frames of images with and without illumination and displaying them in real time, it is possible to accurately check the image at the time of shooting. In addition, the power consumption of lighting during live view is reduced.

  FIG. 10 is a time chart for explaining the live view synthesis of the first embodiment. When this corresponds to FIG. 9, the captured image of frame 2 corresponds to the image of FIG. 9A, and the captured image of frame 3 corresponds to the image of FIG. 9C.

  As described with reference to FIG. 9, the display of the image that can reproduce the illumination state at the time of shooting is generated from the two frame images with and without illumination, so the display is generated from the images of frame 1 and frame 2 in FIG. 10. A live view display image is displayed at the timing of frame 3. In addition, a live view display image generated from the images of frame 2 and frame 3 is displayed at the timing of frame 4.

  In this way, the order of illumination and non-illumination of the live view image to be synthesized for each frame is switched, but in this way, the display of the subject is compared with the case where the display is updated only once every two frames. Movements are displayed smoothly.

  Next, correction of the color of the live view image will be described with reference to the flowchart of FIG.

  FIG. 11 is a flowchart for explaining the detailed processing operation of the subroutine “generate live view display image” in step S9 of the flowchart of FIG. 5 including the process of matching the color of the live view image described above with the color of the captured image. It is.

At the time of shooting, in the case of the first embodiment, illumination with color characteristics different from that at the time of live view, that is, illumination by flash emission of a xenon flash, is performed from the illumination color point P _O at the time of live view. ). Since this data is stored in the memory 125 in the lighting unit 100, the BCPU 31 of the camera body 10 performs image color restoration based on this data. Further, as will be described later, the colors stored in the memory 125 are obtained by measuring and storing a plurality of actual emission colors of the LEDs over time, thereby enabling more accurate color restoration.

  When entering this subroutine, first, in step S31, live view image data is read from the image sensor 38, and in subsequent step S32, YC separation processing or the like is performed to generate uncompressed image data. The Next, in step S33, it is determined whether or not the generated image has been taken with illumination. Here, if there is illumination, the process proceeds to step S34, and the illumination light component is extracted by looking at the difference from the adjacent previous frame.

  Next, in step S35, the color deviation data of the illumination at the time of live view and shooting, which is read from the memory 125 of the illumination unit 100, is acquired, and the illumination unit 100 is to be instructed from the camera body 10. The difference between the illumination light amount at the time of shooting and the illumination light amount at the time of live view is calculated. In step S36, based on this data, the image processing circuit 34 performs a color shift process and brightness correction equivalent to the amount of illumination light.

  When the red light image data of the illumination light and the steady light is synthesized in step S37, a live view image corresponding to the photographed image is displayed on the LCD panel 40 on the back of the camera body 10 in the subsequent step S38. Thereafter, the subroutine is exited, and the process proceeds to step S10 in the flowchart of FIG.

  On the other hand, if it is determined in step S33 that the image generated in steps S31 and S32 is an image without illumination, the color restoration process is not performed, and the process proceeds to step S38. Displayed on the panel 40. Thereafter, the subroutine is exited, and the process proceeds to step S10 in the flowchart of FIG.

  Next, with reference to the flowchart of FIG. 12, the color control of the illumination at the time of photographing standby of the 3-chip LED 120 will be described.

  Since the three-chip LED 120 is a three-color composite type, the generated white color is difficult to determine due to manufacturing variations and environmental conditions. For this reason, from the start to the stop of light emission, the light emission color is monitored to take this into consideration, and the color corresponding to the correct captured image is reproduced in the live view display.

  When this routine is entered, first, in step S41, the FCPU 111 reads from the memory 125 the drive current of each LED of the illumination during the previous shooting standby. Next, in step S42, driving of each chip of the LED 120 is started with the current value. In step S43, the colorimetric sensor 121 measures the emission color of the LED 120.

  Next, in step S44, it is determined whether an instruction to turn off the LED is received from the camera body 10. As a result, if it is not turned off, the process proceeds to step S43, and the monitoring of the LED 120 is repeated. If it is turned off, the process proceeds to step S47.

  If a turn-off instruction is given in step S44, the LED drive is stopped in step S45. In step S <b> 48, for example, an average color component under illumination is written in the memory 125. Thereafter, this routine ends.

  FIG. 13 is a flowchart for explaining the detailed operation of the xenon flash emission control in the subroutine “shooting operation” in step S24 of the flowchart of FIG.

  When this subroutine is entered, first, in step S51, the FCPU 111 in the illumination unit 100 receives the light emission amount data of the flash light emitting element (xenon flash) 113 by communication from the camera body 10 side.

  Next, in step S52, light emission by the flash light emitting element 113 is started in synchronization with the shutter opening timing. Then, in the subsequent step S53, light emission is continued for a time corresponding to the light emission amount. When the light emission time corresponding to the received light emission amount elapses, the process proceeds to step S54 and the light emission of the flash light emitting element 113 is stopped.

  Thus, the shooting operation subroutine using the xenon flash is completed.

  As described above, according to the first embodiment, the lighting mode (intermittent) of the LED, which is the illumination device, is determined depending on whether the live view is operating or in the observation state with the optical viewfinder at the time of shooting standby. Lighting or continuous lighting), the emission color, and the brightness of the light emission are switched, so that optimum illumination with low power consumption is possible. In addition, since a xenon flash is used during shooting, the amount of light is sufficient, and the color component of the illumination light is different from the LED at the time of live view, but it can be corrected and live view display can be performed in real time. The captured image can be previewed correctly.

  In the case of live view, the illumination is turned on and off for each frame, the components of the illumination are extracted, and the balance between the illumination and the steady light predicted at the time of shooting is corrected and displayed. And the photographed image better match, and the illumination light may be weaker than that at the time of photographing, so that the power consumption is low and a live view using illumination for a long time is possible.

  In addition, since the frame is updated every time one frame is acquired while switching the acquisition order with and without illumination, the movement of the image is smoother than the update once every two frames.

  Furthermore, since the color component of the LED illumination is monitored and recorded during the live view monitor, even if a color shift of the LED occurs in the middle, it can be detected and color correction of the display image can be performed. Regardless of the LED driving conditions, a correct captured image can be previewed.

  In addition, when the colors of the live view and the photographed image are matched, the live view side is corrected without correcting the color of the photographed image, which shortens the processing time after photographing and is advantageous for continuous shooting.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In the second embodiment, the configuration of the camera system is the same as that of the first embodiment described above, except that the white LED 116 is used when the optical viewfinder is used and when photographing is performed.

  A white LED with a single-color chip and a phosphor reflector is smaller in color variation due to control compared to a type that generates white by combining three colors, and is small in size, including drive circuits, even for high-intensity and large-sized ones Can be cheaper. For this reason, when using an optical viewfinder that requires a greater amount of light, or when shooting, a type of LED such as the one-chip white LED 116 is smaller and less expensive.

  In the second embodiment, since it is possible to cover with the sensitivity of the imaging device during live view, the 3-chip LED 120 is used, and the 1-chip white LED 116 is used during observation and photographing with the optical viewfinder. .

  In the second embodiment described below, the configuration and basic operation of the camera system are the same as the configuration and operation of the camera system of the first embodiment shown in FIGS. Therefore, with respect to these configurations and operations, the same reference numerals are given to the same portions, and illustration and description thereof will be omitted, and only different operations will be described.

  14 and 15 are flowcharts for explaining the operation at the time of photographing by the camera in the second embodiment of the present invention.

  In this flow chart, steps S61 to S63, steps S65 to S70, and steps S72 to S72, other than steps S64 to S86, which are related to LED lighting control, such as steps S64 and S71 during standby for shooting, and steps S84 to S86 of operations at the time of shooting. Since the processing operations of S83 and S87 are the same as steps S1 to S3, steps S5 to S10, steps S12 to S23, and step S27 of the flowcharts of FIGS. 5 and 6 described above, refer to the corresponding step numbers. The description here is omitted.

When the camera system of the second embodiment shifts to the live view in step S63, the process shifts to step S64, and the three-chip LED 120 is turned on with a drive current corresponding to white 1 (color is point _PO ). Is done. On the other hand, when the optical finder is used, the process proceeds to step S71, and the one-chip white LED 116 is turned on. This LED is manufactured to have a color temperature of point P ₁ with a driving current when using the optical finder.

The optical viewfinder of the present embodiment, to match the illumination of the white LED, is calibrated color of the glass material, when viewed with the naked eye was illuminated with a color point P _1, the color points P _O It is equivalent to the illuminated live view image.

At the time of shooting, the one-chip white LED 116 is turned on in step S84. In this case, a large current is supplied to obtain luminance. At this time, the color component is at the level of the point P ₂ shown in FIG. 4 because the current is larger than the driving current when the optical finder is used.

  Thus, when the LED lighting is started in step S84, a shooting operation is performed in subsequent step S85. Further, when the one-chip white LED 116 is turned off in step S86, the process proceeds to step S61.

  At the time of photographing according to the present embodiment, the color component under illumination is detected by the color sensor 117 and stored in the memory 125. This is the same as the processing operation described in the flowchart of FIG. 12 of the first embodiment described above.

  In the second embodiment, the color component cannot be controlled, but high brightness is required with an LED composed of a blue LED and a phosphor reflector, which is easy to realize high brightness white with an inexpensive and easy driving method. Since the illumination when using the optical finder and photographing is performed, the entire system can be realized in a small size and at a low cost.

  Further, since it is not a flash like a xenon flash, it can be photographed even with a high-speed shutter of a focal plane shutter that does not have a long illumination time and does not fully open. In addition, it is not necessary to consume a large amount of power to store the light emission energy of the xenon flash.

  As a modification of the second embodiment, when using the optical finder and when photographing, the LED 120 constituted by a three-color chip is also turned on, and the color component is emitted together with the one-chip white LED 116. Accordingly, it is possible to increase the brightness of the illumination when using the optical viewfinder and when photographing.

  In the first to third embodiments described above, the camera body and the illumination unit are not separate, and the camera may be provided with illumination devices such as built-in flash and LED. Further, the lens may not be detachable but may be a camera integrated type. Further, the camera body and the lighting unit may not be provided with a control circuit such as a CPU separately, and one arithmetic control circuit may control the camera operation and the lighting control.

  The flash light emitting element and the continuous light emitting element do not have to be one each, and may be configured by a plurality of combinations.

  For live view, when the camera is not a single-lens reflex camera using a quick return mirror, for example, when a semi-transparent fixed mirror is used, the up / down operation of the mirror is unnecessary. In addition, when using a lens shutter type power camera instead of a single-lens reflex camera, it is not necessary to move up and down the mirror. Therefore, when the live view image is displayed, the above-mentioned illumination for live view can be turned on. Good.

  In addition, a continuous lighting device such as LED, or a part of the flash light emitting device may be separate and independent, and all the lighting devices are installed away from the camera and operate in cooperation with wireless communication May be.

  Also, when generating one live view image from two adjacent frames, based on the output of the image shift detection means or the image shift detection means for detecting the shift of the image pattern, the shift amount due to the difference in acquisition time is corrected and superimposed. If the live view image is also displayed, it is possible to prevent the live view image from becoming unclear due to the influence of camera shake or subject shake.

  As mentioned above, although embodiment of this invention was described, in the range which does not deviate from the summary of this invention other than embodiment mentioned above, this invention can be variously modified.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

1A and 1B show an appearance of a camera system according to a first embodiment of the present invention, in which FIG. 1A is a perspective view seen from the front side of the camera, and FIG. It is a conceptual diagram which shows the optical system of the camera system in the 1st Embodiment of this invention. It is a block diagram which shows schematic structure of the electric circuit of the camera system in the 1st Embodiment of this invention. It is a chromaticity diagram (xy color chart) of xy display. 4 is a flowchart for explaining an operation at the time of photographing by the camera in the first embodiment of the present invention. 4 is a flowchart for explaining an operation at the time of photographing by the camera in the first embodiment of the present invention. It is the figure which showed the example of the drive current of 3-chip LED120 in the 1st Embodiment of this invention. It is a time chart for demonstrating the light emission state of LED at the time of imaging | photography standby in the 1st Embodiment of this invention. It is a figure for demonstrating the production | generation method of the image of the live view in the 1st Embodiment of this invention. It is a time chart for demonstrating the live view composition of the 1st Embodiment of this invention. FIG. 6 is a flowchart for explaining detailed processing operations of a subroutine “live view display image generation” in step S9 of the flowchart of FIG. 5 including a process of matching the color of the live view image with the color of the captured image. It is a flowchart for demonstrating the color control of the illumination at the time of imaging | photography standby of 3-chip LED120. 7 is a flowchart for explaining detailed operation of light emission control of a xenon flash in a subroutine “shooting operation” in step S24 of the flowchart of FIG. 6. It is a flowchart for demonstrating the operation | movement at the time of imaging | photography of the camera in the 2nd Embodiment of this invention. It is a flowchart for demonstrating the operation | movement at the time of imaging | photography of the camera in the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Camera body, 11 ... Power switch, 12 ... Release switch, 13 ... Live view changeover switch, 14 ... Cross button, 15, 40 ... LCD panel, 17 ... Eyepiece, 18 ... Hot shoe, 21 ... Quick return mirror, 22, 38 ... Imaging device, 23 ... Finder screen, 24 ... Pentaprism, 25 ... Eyepiece, 27, 32 ... Photometric device, 31 ... Body control circuit (BCPU), 33 ... Mirror drive circuit, 34 ... Image processing circuit, 35 ... Recording medium, 37 ... Image sensor driver, 39 ... LCD driver, 42 ... Various switches, 43, 92, 125 ... Memory, 80 ... Lens unit, 81 ... Shooting lens, 91 ... Lens control circuit (LCPU), 100 ... Illumination unit, 101... Flash emission part, 102, 116... 1 chip type white LED, 10 , 120 ... 3-chip LED, 105 ... lighting head, 106 ... lighting device body, 107 ... shoe, 111 ... lighting control circuit (FCPU), 112 ... flash light emission drive control circuit, 113 ... flash light emitting element, 115, 119 ... LED Driver, 117, 121 ... Colorimetric sensor, 124 ... Colorimetric sensor processing circuit, J1, J2 ... Communication contact.

Claims (7)

A camera system having a live view mode that continuously captures and displays subject images that can be interlocked with each other, and an illumination device that illuminates the subject with auxiliary light,
The illuminating device uses the auxiliary lighting as a first lighting state suitable for a low luminance and a long time and a high luminance and a short time compared to the first lighting state. And a lighting control means for switching to and lighting the second lighting state in which the color component is different,
At least one of the camera and the lighting device includes storage means for storing the illumination color components of the first lighting state and the second lighting state,
The above camera
Control means for controlling to turn on the auxiliary light in the first lighting state in the live view mode and in the second lighting state in capturing a captured image;
Based on the data stored in the storage unit, the color of the display image illuminated in the first lighting state is the color of the captured image illuminated with the auxiliary light in the second lighting state. Photographed image correction means for correcting to be substantially equal;
A camera system characterized by having The illumination device further illuminates the auxiliary light at a rate of once per a plurality of frames in synchronization with the image capture timing in the live view mode.
The above camera
Lighting instruction means for instructing the lighting device in a lighting state during live view;
The live view mode display image acquired with the auxiliary light turned on, the live view mode display image acquired without the auxiliary light turned on, and the output of the storage means are predicted to be generated at the time of shooting. Live view display image generation means for displaying an image as a live view image;
The camera system according to claim 1, further comprising:   The camera extracts an image component by illumination from the frame image with illumination of the auxiliary light and the frame image without illumination, and predicts the illumination image at the time of shooting as a predicted image based on the output of the storage means The camera system according to claim 2, wherein the image at the time of photographing is predicted and displayed by superimposing the predicted image on the image without illumination. A taking lens,
An image sensor that captures an image of a subject passing through the photographing lens;
Display means for displaying a subject image based on the output of the image sensor;
An illumination device that illuminates the subject with auxiliary light;
The auxiliary light is composed of a first lighting state suitable for low brightness and long time, and a high brightness and short time suitable for the first lighting state. The first lighting state has a color component. A lighting control means for switching to and lighting the different second lighting state;
Storage means for storing the illumination color components of each of the first lighting state and the second lighting state;
Control means for controlling to turn on the auxiliary light in the first lighting state at the time of the live view mode in which the subject image is continuously captured and displayed, and in the second lighting state at the time of capturing the captured image;
Based on the data stored in the storage unit, the color of the display image illuminated in the first lighting state is the color of the captured image illuminated with the auxiliary light in the second lighting state. Photographed image correction means for correcting to be substantially equal;
A camera system characterized by comprising: The illumination device illuminates the auxiliary light at a rate of once per a plurality of frames in synchronization with the image capture timing in the live view mode,
Furthermore,
Lighting instruction means for instructing the lighting device in a lighting state during live view;
The live view mode display image acquired with the auxiliary light turned on, the live view mode display image acquired without the auxiliary light turned on, and the output of the storage means are predicted to be generated at the time of shooting. Live view display image generation means for displaying an image as a live view image;
The camera system according to claim 4, comprising:   Extracting an image component by illumination from the frame image with illumination of the auxiliary light and the frame image without illumination, predicting the illumination image at the time of photographing as a predicted image based on the output of the storage means, and 6. The camera system according to claim 5, further comprising prediction display means for predicting and displaying the image at the time of photographing by superimposing the prediction image on the image without illumination. An image generation method of a camera system having a camera having a live view mode that continuously captures and displays subject images that can be linked to each other, and an illumination device that illuminates the subject with auxiliary light,
The auxiliary light is composed of an illumination color component in a first lighting state suitable for low brightness and a long time, and the first lighting state in which the auxiliary light is suitable for high brightness and a short time compared to the first lighting state. Storing an illumination color component in a second lighting state having different color components;
Illuminating the auxiliary light in a first lighting state suitable for low brightness and long time in a live view mode in which a subject image is continuously captured and displayed;
Illuminating the auxiliary light in a second lighting state that is suitable for high brightness and a short time compared to the first lighting state and having a color component different from that of the first lighting state at the time of capturing a captured image; ,
The color of the display image in the live view mode illuminated in the first lighting state is substantially the same as the color of the captured image in which the auxiliary light is illuminated in the second lighting state based on the stored illumination color component. Correcting to be equal, and
An image generation method for a camera system characterized by comprising:

Images