JP2010175622A - Imaging apparatus, stroboscopic device, and stroboscopic photography system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable proper strobe photography even when the charging voltage of a capacitor of a strobe device is lowered by irradiation of auxiliary light for automatic focus adjustment.
Light emitting means for emitting light using electric energy charged in a capacitor, charging voltage detecting means for detecting a charging voltage of the capacitor, focus detecting means for detecting focus of a subject, and the charging voltage detecting means A light emission control means that permits light emission of the light emission means when the charging voltage of the capacitor detected by the step is equal to or higher than a predetermined voltage, and the light emission control means permits light emission for the focus detection The first predetermined voltage is set as the predetermined voltage, and when light emission for photographing is permitted, a second predetermined voltage that is lower than the first predetermined voltage is set as the predetermined voltage.
[Selection] Figure 3

Description

  The present invention relates to a strobe photographing system that uses strobe light as auxiliary light for automatic focus adjustment of an imaging apparatus.

2. Description of the Related Art Conventionally, in an imaging device having an autofocus adjustment function, particularly an imaging device that performs autofocus detection by a phase difference detection method, when the subject is insufficiently bright or has insufficient contrast, the subject is used for focus detection. On the other hand, what irradiates auxiliary light is known. As a light source for irradiating this auxiliary light, a light source for flashing light to obtain a necessary brightness has been proposed in Patent Document 1 and the like.
JP 2000-111791 A

  However, when auxiliary light for automatic focus adjustment is required, the charging voltage of the capacitor of the strobe device decreases because the strobe device flashes. Therefore, in a strobe device that does not allow flash emission unless the charge voltage is equal to or higher than the predetermined voltage, if the charge voltage becomes less than the predetermined voltage due to the auxiliary light emission, the flash light is flashed until the charge voltage reaches the predetermined voltage after the auxiliary light emission. There is a problem that photographing with light emission cannot be performed. On the other hand, a strobe device that emits flash light even when the charging voltage is lower than a predetermined voltage has a problem that proper exposure cannot be performed by performing image capturing without flashing at a required light emission amount.

  The present invention has been made in view of the above problems, and an object of the present invention is to perform appropriate flash photography even when the charging voltage of the condenser of the flash device is reduced by irradiation of auxiliary light for automatic focus adjustment. To do.

  An imaging apparatus according to the present invention includes a light emitting unit that emits light using electrical energy charged in a capacitor, a charging voltage detecting unit that detects a charging voltage of the capacitor, a focus detecting unit that performs focus detection of a subject, A light emission control means for allowing the light emission means to emit light when the charging voltage of the capacitor detected by the charge voltage detection means is equal to or higher than a predetermined voltage, and the light emission control means emits light for the focus detection. Is set to the first predetermined voltage as the predetermined voltage, and the second predetermined voltage is lower than the first predetermined voltage as the predetermined voltage when light emission for photographing is permitted. Is set.

  The strobe device according to the present invention is a strobe device that can be attached to and detached from the imaging device, and includes a light emitting unit that emits light using electrical energy charged in a capacitor, and a charging voltage detecting unit that detects a charging voltage of the capacitor. And a light emission control means for allowing the light emission means to emit light when the charging voltage of the capacitor detected by the charge voltage detection means is equal to or higher than a predetermined voltage, and the light emission control means The first predetermined voltage is set as the predetermined voltage when allowing light emission for focus detection by the apparatus, and the predetermined voltage is set as the predetermined voltage when allowing light emission for photographing by the mounted imaging apparatus. A second predetermined voltage that is lower than the first predetermined voltage is set.

  The strobe photographing system according to the present invention is a strobe photographing system having an imaging device and a strobe device, and detects a charging voltage of the capacitor, light emitting means for emitting light using electric energy charged in the capacitor. A charge voltage detection means; a focus detection means for detecting the focus of the subject; and a light emission control means for permitting the light emission means to emit light when a charge voltage of the capacitor detected by the charge voltage detection means is a predetermined voltage or higher. The light emission control means sets a first predetermined voltage as the predetermined voltage when the light emission for the focus detection is permitted, and the predetermined light voltage when the light emission for photographing is permitted. A second predetermined voltage that is lower than the first predetermined voltage is set as the voltage.

  According to the present invention, appropriate flash photography can be performed even when the charging voltage of the condenser of the flash device decreases due to irradiation of auxiliary light for automatic focus adjustment.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram of a flash photographing system including an imaging device and a flash device that can be attached to and detached from the imaging device according to an embodiment of the present invention.

  Reference numeral 100 denotes a digital camera as an imaging apparatus in the present embodiment. Reference numeral 101 denotes a lens unit that can be attached to and detached from a digital camera body including a plurality of lens groups. The lens unit 101 communicates with the camera microcomputer 126, controls the lens control circuit 101 a inside the lens unit 101, and moves the focusing lens in the lens unit 101 to focus. Also included are an operation switch (not shown) for selecting an autofocus mode in which the digital camera 100 automatically focuses and a manual focus mode in which the photographer manually focuses. The amount of movement of the focus lens is controlled based on the output of the distance measuring circuit 117. An aperture control circuit 101b is provided in the lens unit 101 to change the optical aperture value. A quick return mirror 102 is disposed in the photographing optical path and is movable between a position for guiding the subject light from the lens unit 101 to a finder optical system (not shown) and a position for retracting it outside the photographing optical path. Reference numeral 103 denotes a shutter, and reference numeral 104 denotes an optical filter covered with dustproof glass. Reference numeral 105 denotes an image sensor that converts an optical image into an electrical signal, and reference numeral 106 denotes an A / D converter that converts an analog signal output from the image sensor 105 into a digital signal. Reference numeral 107 denotes an image processing circuit, which performs predetermined pixel interpolation processing on image data from the A / D converter 106 or image data from the memory control circuit 111 based on processing data added to the image data. Perform development processing. A timing generation circuit 108 supplies a clock signal and a control signal to the image sensor 105 and the A / D converter 106. The timing generation circuit 108 is controlled by a memory control circuit 111 and a camera microcomputer 126 described later. A memory control circuit 111 controls the A / D converter 106, the image processing circuit 107, the timing generation circuit 108, the image display memory 112, the memory 113, and the compression / decompression circuit 114.

  Output data of the A / D converter 106 is written into the image display memory 112 or the memory 113 via the image processing circuit 107 and the memory control circuit 111. Reference numeral 110 denotes a display unit composed of an LCD or the like. Display image data written in the image display memory 112 is displayed on the display unit 110 by the display control circuit 109.

  The display unit 110 is arranged mainly on the back surface of the digital camera 100, and displays a menu screen that prompts the photographer to perform an operation and a reproduced image of the image file. The display unit 110 can also display an imaging screen as a finder by sequentially displaying image data obtained by processing the output from the image sensor 105 by the image processing circuit 107. Therefore, the photographer can take a picture while confirming the framing of the subject on the display unit 110. Reference numeral 113 denotes a memory that holds processing data used when the image processing circuit 107 develops image data and calculation results of AF (auto focus) / AE (automatic exposure) / WB (white balance). . Further, an area as an image buffer for temporarily storing uncompressed captured image data, an area as a work buffer for storing temporarily used data, and a file for storing compressed image data compressed by the compression / decompression circuit 114 It includes an area as a buffer. Furthermore, the memory 113 has a storage capacity sufficient to store a predetermined number of still images and a moving image for a predetermined time. Thereby, even in the case of continuous shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to the memory 113 at high speed.

  Reference numeral 114 denotes a compression / decompression circuit that compresses and decompresses image data as JPEG data by adaptive discrete cosine transform (ADCT) or the like. The image data stored in the memory 113 is read and subjected to compression processing or decompression processing. Data is written to the memory 113. Reference numeral 115 denotes a shutter control circuit that controls the shutter 103. Reference numeral 116 denotes a mirror control circuit that drives and controls the quick return mirror in and out of the photographing optical path. Reference numeral 117 denotes a distance measurement control circuit. In the present embodiment, the focus detection is performed based on a known phase difference method based on the output of a focus detection sensor (not shown). The lens unit 101 is based on the detection result. Control the focusing lens. A photometry control circuit 118 measures the luminance of the subject and controls exposure based on the output.

  Next, each operation member will be described. Reference numerals 120 and 121 denote operation members for inputting various operation instructions of the camera microcomputer 126, and include various button switches, a dial, a touch panel, and the like. Here, these operation members will be specifically described.

  A release switch 120 includes a switch that is turned on when the release button is pressed halfway (SW1), and instructs the start of shooting preparation operations such as AF processing and AE processing. Furthermore, the release switch 120 includes a switch that is turned on when the release button is fully pressed (SW2). The signal read from the image sensor 105 is transferred to the memory 113 via the A / D converter 106 and the memory control circuit 111. An imaging process for writing is performed. Subsequently, the image processing circuit 107 is used to read out white balance correction processing, development processing, and developed image data from the memory 113 in accordance with the white balance mode set for the image data, and the compression / decompression circuit 114. Compress with. Subsequently, an instruction to start an operation of a series of processing called recording processing for writing image data on the recording medium is given. Reference numeral 121 denotes a menu operation switch, which includes a menu key (not shown), a set key, a cross key, a reproduction key, and the like. Various operations such as selection of various setting changes such as camera shooting conditions and development conditions, and image file playback instructions can be performed while viewing the screen display displayed on the display unit 110. In the present embodiment, a plurality of AF control modes can be selected as an autofocus control mode (hereinafter referred to as AF control mode). For example, a one-shot AF mode (first control mode) in which focus detection is performed once by operating the release switch 120, and an AI servo AF mode in which focus detection is repeatedly performed on a moving object while the release switch is pressed. (Second control mode). In addition, it is also possible to select an AI focus AF mode (third control mode) that automatically switches to the AI servo AF mode when it is determined that the subject is a moving object after focus detection in the one-shot AF mode.

  Reference numeral 126 denotes a microcomputer (camera microcomputer) that controls the digital camera 100 configured as described above. The nonvolatile memory 119 stores various programs such as a program for performing an imaging process, a program for performing an image process, and a program for recording image file data created on a recording medium on the recording medium. In addition, various programs such as an OS that realizes and executes the multitask configuration of the above program, adjustment values for performing various controls, and the like are also recorded.

  A power control circuit 122 includes a battery detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like, and detects whether or not a battery is installed, the type of battery, and the remaining battery level. Then, the DC-DC converter is controlled based on the detection result and the instruction of the camera microcomputer 126, and a necessary voltage is supplied to each unit including the recording medium for a necessary period. A recording medium control circuit 123 controls a recording medium such as a memory card, and a connector 124 connects to the recording medium such as a memory card.

  Reference numeral 125 denotes an interface with the flash device 200, which is a flash communication terminal that enables communication between the camera microcomputer 126 and the flash microcomputer 220. The strobe communication terminal has an X terminal for outputting a light emission start signal, an SCLK terminal for outputting a communication clock with a strobe microcomputer 220, which will be described later, and a SCHG terminal for transmitting to the camera microcomputer 126 whether or not the strobe device 200 can emit light. Yes. In addition, there is an SDO terminal that transmits data from the camera microcomputer 126 to the flash microcomputer 220 in synchronization with the SCLK terminal, and an SDI terminal that receives data from the flash microcomputer to the camera microcomputer 126 in synchronization with the SCLK terminal. Reference numeral 300 denotes a recording medium such as a memory card or a hard disk. Here, the recording medium 300 is a memory card composed of a semiconductor memory. The recording medium 300 includes a connector 301 that connects to the digital camera 100, a recording unit control circuit 302 that controls the recording unit 303 as an interface with the digital camera 100, and a recording unit 303 that includes a semiconductor memory.

  Next, the configuration of the strobe device 200 in the present embodiment will be described with reference to FIG.

  A battery 201 is a power source, 202 is a booster circuit that boosts the battery voltage to several hundred volts, and 203 is a main capacitor that stores electrical energy that is an output of the booster circuit. Reference numerals 204 and 205 denote resistors that divide the voltage of the main capacitor 203 used for detecting the charging voltage of the main capacitor 203 into a predetermined ratio, and are connected to the AD input terminal of the strobe microcomputer 220. Reference numeral 206 denotes a discharge tube as a light emitting means, reference numeral 207 denotes a trigger generation circuit that excites the discharge tube 206 to emit light, and reference numeral 208 denotes a light emission control circuit that controls light emission of the discharge tube 206.

  A data selector 209 selects D0, D1, and D2 and outputs them to Y by a combination of two inputs Y0 and Y1. 210 is a comparator for controlling the amount of light emitted by flat light emission, 211 is a comparator for controlling the amount of light emitted during flash light emission, 214 is a photodiode which is a light receiving sensor for controlling flat light emission, and a discharge tube 206 which is a light emitting means. Monitor the light output. A photometric circuit 212 amplifies a minute current flowing through the photodiode 214 and converts the photocurrent into a voltage.

  Reference numeral 215 denotes a photodiode which is a light receiving sensor for controlling flash light emission, and monitors the light output of the discharge tube 206 which is a light emitting means. Reference numeral 213 denotes an integration circuit for logarithmically compressing the photocurrent flowing through the photodiode 215 and compressing and integrating the light emission amount of the discharge tube 206.

  Reference numeral 216 denotes a display unit such as an LCD for displaying the operation state of the strobe. Reference numeral 217 denotes a display LED that indicates that the strobe device is at a predetermined charge voltage level or higher and can emit light. Reference numeral 218 denotes a dimming display LED that displays that the strobe device emits light with an appropriate amount of light.

  Reference numeral 220 denotes a microcomputer (strobe microcomputer) that controls the operation of the entire strobe device 200 having the above-described configuration, and incorporates a program for performing light emission processing, adjustment values for performing various controls, an A / D converter, and the like. Further, the flash microcomputer 220 permits the light emission of the discharge tube 206 by controlling the light emission control circuit 208 if the charging voltage of the main capacitor 203 is equal to or higher than a predetermined voltage.

  Reference numeral 219 denotes an interface with the digital camera 100, which is a strobe communication terminal that enables communication between the camera microcomputer 126 and the strobe microcomputer 220. The strobe communication terminal transmits an X terminal for inputting a light emission start signal from the digital camera 100 described above, a CLK terminal for inputting a communication clock from the digital camera 100 described above, and transmits whether the strobe device 200 can emit light to the camera microcomputer 126. The CHG terminal is provided. In addition, it has a DI terminal that receives data from the camera microcomputer 126 in synchronization with the CLK terminal, and a DO terminal that transmits data from the flash microcomputer 220 to the camera microcomputer 126 in synchronization with the CLK terminal.

  Next, an imaging process sequence using flash auxiliary light will be described with reference to the flowchart of FIG.

  First, in step S301, when SW1 is pressed and photographing processing is started, the process proceeds to step S302. In step S302, the camera microcomputer 126 confirms whether or not the focus detection mode is a mode using auxiliary light. In this embodiment, it is possible to select an auto focus mode in which focus detection is performed and lens driving for focus adjustment is automatically performed, and a manual focus mode in which lens drive for focus adjustment is not performed automatically without performing focus detection. It has a simple configuration. If the auto focus mode is selected, the process proceeds to step S304. On the other hand, if the manual focus mode is selected, no auxiliary light is emitted, and the process proceeds to step S303.

  In step S303, the camera microcomputer 126 instructs the flash microcomputer 220 to set the light emission permission voltage level to M (second predetermined voltage) via the flash communication terminal 125. On the other hand, in step S304, the camera microcomputer 126 instructs the flash microcomputer to set the light emission permission voltage level to H (first predetermined voltage) via the flash communication terminal 125. Here, the voltage levels corresponding to the light emission permission voltage levels H and M have a relationship of H> M. That is, H has a higher voltage level.

  In step S305, the camera microcomputer 126 confirms the SCHG terminal and confirms whether or not the charging voltage of the flash device 200 is equal to or higher than the light emission permission voltage level. If the charging voltage is equal to or higher than the light emission permission voltage level, the process proceeds to step S306. On the other hand, if the charging voltage is less than the light emission permission voltage level, the process returns to step S301.

  In step S306, if the autofocus mode is selected, the focus detection process is performed by the ranging circuit 117 and the lens control circuit 101a to perform autofocus control and control the focusing lens to the in-focus position. Details of the focus detection processing will be described later with reference to FIGS. In step S307, the camera microcomputer 126 instructs the flash microcomputer 220 to set the light emission permission voltage level to M via the flash communication terminal 125. Note that when the manual focus mode is selected, the processing of S306 and S307 may be omitted. In step S308, photometry processing is performed using the photometry circuit 118, and a shutter control value and an aperture control value are determined according to the set shooting mode.

  In step S309, it is confirmed whether or not the release switch SW2 is pressed. If SW2 is pressed, the process proceeds to step S310. On the other hand, if SW2 is not pressed, the process proceeds to step S312 to check whether SW1 is continuously pressed. If SW1 is pressed, the process returns to step S309 to confirm the release switch SW2. If SW1 is released, the process returns to step S301.

  Next, in step S310, the camera microcomputer 126 instructs the flash microcomputer 220 via the flash communication terminal 125 about the light emission intensity and the light emission time during the preliminary light emission, and performs a known flash preliminary light emission process. At this time, photometry is also performed using the photometry circuit 118. In step S311, the camera microcomputer 126 instructs the flash microcomputer 220 via the flash communication terminal 125 to set the light emission permission voltage level to L (third predetermined voltage). Here, there is a relationship of M> L between the light emission permission voltage levels M and L. That is, M has a higher voltage level.

  In step S313, the mirror control circuit 116 is instructed to perform so-called mirror up, in which the quick return mirror 102 is retracted out of the photographing optical path. Next, in step S314, charge accumulation in the image sensor 105 starts. In step S315, the shutter control circuit 115 is instructed to run the shutter.

  Next, the process proceeds to step S316, in which exposure is performed by controlling light emission of the strobe device 200 according to the light emission amount obtained based on the photometric result obtained in the photometric process in step S308 and the photometric result obtained in the preliminary light emission process in step S310. Done. At this time, the camera microcomputer 126 instructs the flash device 200 via the flash communication terminal 125 about the light emission intensity and the light emission time during the main light emission.

  Next, in step S317, the shutter control circuit 115 is instructed to close the shutter, and in the next step S318, charge accumulation in the image sensor 105 is terminated. In the next step S319, mirror return is performed to return the quick return mirror to the photographing optical path. In the next step S320, an image signal is read from the image sensor 105, and the image data processed by the A / D converter 106 and the image processing circuit 107 is temporarily stored in the memory 113. When all image signals are read from the image sensor 105, a predetermined development process is performed on the image signals to create image data. In the next step S321, the created image data is recorded as an image file in the recording medium 300, and a series of photographing processes is completed.

  Next, using the flowchart shown in FIG. 4, the charging process of the strobe device 200 and the process of transmitting whether or not to emit light to the digital camera 100 based on the charging voltage determination result will be described.

  When the strobe device 200 is activated, in step S401, the voltage divided by the main capacitor 203 is AD-converted by the AD converter built in the strobe microcomputer 220, and the charging voltage of the main capacitor 203 is confirmed. In the next step S402, if the charging voltage of the main capacitor 203 is equal to or higher than the light emission permission voltage level, the process proceeds to step S403, whereas if the charging voltage is less than the light emission permission voltage level, the process proceeds to step S404.

  The light emission permission voltage level is set to the light emission permission voltage level H immediately after the strobe device is activated, but is instructed by the camera microcomputer 126 via the strobe communication terminal 125 in accordance with the sequence of the digital camera 100. If the photographing process is being performed, voltages corresponding to the light emission permission voltage levels H and M instructed by the camera microcomputer 126 according to the selected focus detection mode are set as the comparison voltages. Here, the first predetermined voltage corresponding to the light emission permission voltage level H is the voltage of the main capacitor generated by the emission of auxiliary light controlled during the focus detection process with respect to the second predetermined voltage corresponding to the light emission permission voltage level M. A voltage obtained by adding a voltage equal to or greater than the amount of drop is set. The second predetermined voltage is set to a voltage obtained by adding a voltage equal to or greater than the voltage drop amount due to the preliminary light emission to the third predetermined voltage corresponding to the light emission permission voltage level L. Therefore, the first predetermined voltage is set to be equal to or higher than the voltage obtained by adding the voltage drop due to the preliminary light emission and the voltage drop amount due to the flash auxiliary light to the voltage capable of the main light emission.

  If the process proceeds to step S403 as a result of the determination in step S402, the camera microcomputer 126 is notified via the CHG terminal that light can be emitted, and the possibility display LED indicating that light can be emitted is lit and the process proceeds to step S405. move on. On the other hand, when the process proceeds to step S404, the camera microcomputer 126 is notified that the issuance is impossible via the CHG terminal, and the possible display LED is turned off to indicate that the light cannot be emitted, and the process proceeds to step S405.

  In step S405, it is confirmed whether the charging voltage of the main capacitor 203 confirmed in step S402 is equal to or higher than the charging upper limit voltage level F of the charging voltage of the strobe device 200. The charge upper limit voltage level F is higher than the light emission permission voltage level H. If the charging voltage is equal to or higher than the charging upper limit voltage level F, the charging is completed and the process proceeds to step S406, the charging is stopped, and the charging process is ended. On the other hand, if the charging voltage is lower than the charging upper limit voltage level F, the process proceeds to step S407 to start or continue charging, and returns to step S401 to repeat a series of processes.

  Next, focus detection processing will be described using the flowchart shown in FIG.

  When the focus detection process is started, focus detection is performed without irradiating auxiliary light in step S501. In the next step S502, the camera microcomputer 126 determines whether or not focus detection has been performed without irradiating auxiliary light. If focus detection has been performed, that is, it is necessary to irradiate auxiliary light for focus detection processing. If not, the process proceeds to step S503. If focus detection cannot be performed without irradiating the auxiliary light, the process proceeds to step S506, and the focus detection process is performed by irradiating the auxiliary light. Details of focus detection by irradiating auxiliary light will be described with reference to FIG. If focus detection can be performed by irradiating the auxiliary light in step S507, the process proceeds to step S503. On the other hand, if the focus cannot be detected even when the auxiliary light is irradiated, the process proceeds to step S508, and the focus detection is performed using a display unit (not shown) such as an LED. Exit.

  In step S503, the focus detection calculation is performed using the signal from the focus detection sensor, and the movement amount (defocus amount) of the focusing lens is calculated. Subsequently, in step S504, the camera microcomputer 126 determines whether or not the focusing lens needs to be moved based on the calculation result obtained in step S503. If the defocus amount is smaller than the predetermined value, the focus detection process is terminated. To do. If the value is equal to or greater than the predetermined value, the process proceeds to step S505, and the focusing lens is moved based on the calculation result in step S503. Thereafter, in order to determine whether or not the focusing lens has reached the in-focus point after the focusing lens is moved, the process returns to step S501, and thereafter the same operation is repeated.

  Next, the focus detection process performed by irradiating the auxiliary light executed in step S506 of FIG. 5 will be described using the flowchart of FIG. 6 is mainly performed by the camera microcomputer 126.

  First, in step S601, a counter i that stores the number of flash assist light irradiations is cleared. In the next step S 602, the camera microcomputer 126 instructs the flash microcomputer 220 to irradiate flash auxiliary light via the flash communication terminal 125 and irradiates the subject with flash light. In the subsequent step S603, it is determined whether or not the amount of accumulated charge by the focus detection sensor is equal to or greater than a predetermined value after the flash auxiliary light is irradiated. As a result, if the value is equal to or greater than the predetermined value, the probability that the focus detection calculation is possible is sufficiently high, so the process proceeds to step S604, and the focus detection by irradiating the auxiliary light is terminated. In this case, focus detection calculation is possible, and the process proceeds to step S503 in FIG.

  On the other hand, if the accumulated amount is less than the predetermined value in step S603, the process proceeds to step S605. In step S605, it is determined whether the counter i has reached the predetermined number imax. If the predetermined number imax has been reached, the process proceeds to step S606. If the predetermined number imax has not been reached, the process proceeds to step S607. When the process proceeds to step S606, it indicates that a sufficient amount of accumulation could not be obtained even when the imax times of auxiliary light radiated in advance were irradiated. In this case, the focus detection calculation is impossible, and the process proceeds to step S508 in FIG. On the other hand, when the process proceeds to step S607, the counter i is incremented to count the number of times of flash auxiliary light irradiation, and the process returns to step S602 to repeat the flash auxiliary light irradiation and continue focus detection.

  Next, the change in the light emission permission voltage level during the photographing process will be described with reference to FIGS. FIG. 7A shows a light emission waveform at the time of photographing processing accompanied by a focus detection process with flash auxiliary light and a change in the charging voltage of the main capacitor 203, and FIG. 7B shows a light emission waveform at the time of photographing processing without flash auxiliary light and the main. It is a figure showing the change of the charging voltage of the capacitor | condenser. 7A and 7B, (a) shows a light emission waveform at the time of photographing processing such as flash auxiliary light, preliminary light emission, and main light emission, and (b) shows a charging voltage of the main capacitor 203. c) shows the light emission permission voltage level. Further, the amount of decrease in the charging voltage of the main capacitor 203 due to each light emission shown in FIGS. 7A and 7B is a value for making it easy to understand the explanation regarding the change in the light emission permission voltage level. It does not necessarily correspond to the amount of charge voltage drop.

  Hereinafter, description will be made in correspondence with the flowcharts of FIGS. 3 to 6 described above. In FIG. 7A, when the irradiation of flash auxiliary light is started at the timing t1 by the focus detection process with auxiliary light as described in step S602 of FIG. 6, the charging voltage of the main capacitor 203 together with the irradiation of the flash auxiliary light. Decreases. FIG. 7A shows a case where the number of times of flash auxiliary light irradiation is imax = 8, and the charging voltage of the main capacitor 203 corresponds to the light emission permission voltage level H at the timing t2 by the eight irradiations. Below the first predetermined voltage. In this case, light emission is not permitted after the end of the focus detection process with flash auxiliary light. Therefore, the emission permission voltage level is set to M at the timing of t3 corresponding to step S307 when the focus detection process is completed. By doing so, the charging voltage of the main capacitor 203 exceeds the second predetermined voltage corresponding to the light emission permission voltage level M. Therefore, preliminary light emission is possible, and preliminary light emission is possible at the timing t4 corresponding to step S310.

  When the preliminary light emission starts at the timing t4, the charging voltage of the main capacitor 203 decreases with the preliminary light emission, and falls below the second predetermined voltage corresponding to the light emission permission voltage level M at the timing t5. In this case, light emission is not permitted after the preliminary light emission is completed. Therefore, the light emission permission voltage level is set to L at the timing of t6 corresponding to step S311 after the end of the preliminary light emission. By doing so, the charging voltage of the main capacitor 203 exceeds the third predetermined voltage corresponding to the light emission permission voltage level L. Therefore, the main light emission becomes possible and the main light emission is performed at the timing of t7 corresponding to step S316. After the main light emission is completed, the light emission permission voltage level is returned to H for the next photographing process.

  FIG. 7B is a diagram showing changes in the light emission waveform and the charging voltage of the main capacitor 203 during the photographing process when the flash assist light is not performed. FIG. 7B shows a case where the main capacitor 203 is not sufficiently charged and the strobe device 200 is being charged.

  In FIG. 7B, as described in step S302, when the manual focus mode is selected and it is not necessary to emit the flash assist light, the emission permission voltage level is set to M at the timing of t1 '. Thereafter, the strobe device 200 continues the charging process described with reference to FIG. 4, and the digital camera 100 determines whether or not the charging voltage of the main capacitor 203 is equal to or higher than the light emission permission voltage level in step S305, that is, the strobe device 200 can emit light. Check whether or not. When the charging voltage of the main capacitor 203 exceeds the second predetermined voltage corresponding to the light emission permission voltage level M at the timing t3 ', preliminary light emission is possible. Here, if the light emission permission voltage level is set to H regardless of whether or not the flash auxiliary light is used, the charging voltage of the main capacitor 203 does not exceed the light emission permission voltage level at the timing of t3 ′. The timing at which light emission is possible will be delayed. However, by controlling the light emission permission level as shown in FIG. 7B, it is possible to reduce the time required from charging to the start of preliminary light emission, and it is possible to take a picture at a timing intended by the photographer. Hereinafter, the processing after the preliminary light emission is the same as that described with reference to FIG.

  As described above, by controlling the light emission permission voltage level as shown in FIG. 7A, it is appropriate even if the charging voltage of the main capacitor 203 is reduced by irradiating auxiliary light for focus detection processing. Can be used for flash photography.

  Further, by controlling the light emission permission voltage level as shown in FIG. 7B, even when the photographing process is started in a state where the charging voltage of the main capacitor 203 is lowered, charging is not performed more than necessary. By doing so, the shooting interval can be shortened.

  As described above, in this embodiment, the light emission permission voltage level of light emission for focus detection (auxiliary light) and light emission for photographing (preliminary light emission, main light emission) can be changed, and auxiliary light is emitted. The light emission permission voltage level is changed depending on whether or not to perform. At this time, the light emission permission voltage level of the auxiliary light is set higher than the light emission permission voltage level at which light emission for photographing can be performed. For example, a voltage level obtained by adding a voltage equal to or higher than the voltage drop amount of the main capacitor due to light emission of the flash auxiliary light to the light emission permission voltage level M for preliminary light emission is set as the light emission permission voltage level H for auxiliary light. In other words, a voltage level obtained by subtracting a voltage equal to or greater than the voltage drop amount of the main capacitor due to the emission of the flash auxiliary light from the light emission permission voltage level H of the auxiliary light becomes the light emission permission voltage level M of the preliminary light emission. Further, after the auxiliary light emission, the light emission permission voltage level is set to the light emission permission voltage level M at which preliminary light emission is possible. By such control, even when auxiliary light is emitted for focus detection, preliminary light emission and main light emission for subsequent photographing can be emitted.

  When the auxiliary light is not used, the light emission permission voltage level is set to a light emission permission voltage level M lower than the voltage level at which the auxiliary light can be emitted. Even without this, it becomes possible to emit light. For this reason, it is possible to shorten the interval between continuous strobe flash photography, and even in continuous photography using a strobe device, it is possible to take pictures at a timing intended by the photographer.

  In the present embodiment, the determination is made based on whether the focus detection mode is the autofocus mode or the manual focus mode as a determination condition for determining whether auxiliary light is necessary. However, the determination is not limited to the focus detection mode. Absent. For example, when the user can arbitrarily set whether or not to use auxiliary light, a configuration in which determination is made according to this setting is also possible.

  In addition, the configuration is such that the light emission permission voltage level is set after confirming whether or not the mode uses auxiliary light. However, in the mode using auxiliary light, photometry is performed before focus detection and based on the result. Thus, it may be determined whether auxiliary light is necessary, and the emission permission voltage level may be set.

  In addition, if there is a mode that performs main flash without performing preliminary flash, such as the manual flash mode in which the photographer can arbitrarily set the main flash output, the flash enable voltage level if such a mode is set It may be controlled not to set M to M. For example, in the case of FIG. 7A, the emission permission voltage level may be set to L instead of M at the timing of t3 corresponding to step S307 when the focus detection process is completed. In the case of FIG. 7B, the time required until the charging voltage exceeds the light emission permission voltage level can be further shortened by setting the light emission permission voltage level to L instead of M at the timing of t1 ′. It is possible to take a picture at a timing more intended by the photographer.

  In addition, when the mode for performing the main light emission without performing the preliminary light emission is set, it is not necessary to consider the decrease in the charging voltage due to the preliminary light emission, so that the auxiliary light emission is permitted as shown in FIG. The light emission permission voltage level may be set to H ′ (fourth predetermined voltage). The fourth predetermined voltage corresponding to the light emission permission voltage level H ′ is a voltage drop of the main capacitor caused by the emission of auxiliary light controlled during the focus detection process with respect to the third predetermined voltage corresponding to the light emission permission voltage level L. A voltage obtained by adding more than the amount of voltage is set. That is, the fourth predetermined voltage is set to a voltage level that is the same as or higher than the voltage obtained by adding the voltage drop amount due to the flash assist light to the voltage that can be emitted. Note that the fourth predetermined voltage does not need to be added with the amount of voltage drop due to the preliminary light emission, and thus can be set to a voltage lower than the first predetermined voltage. Therefore, as shown in FIG. 7C, the auxiliary light can be emitted even if the charging voltage does not reach the light emission permission level H, and the main light emission can be performed without charging following the auxiliary light emission. As a result, it is possible to reduce the time required to perform flash photography in a state of insufficient charging.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described. Note that the configurations of the imaging device and the strobe device in the strobe photographing system of the present embodiment are the same as those of the first embodiment, and thus description thereof is omitted.

  In the present embodiment, unlike the first embodiment, the emission permission voltage level is changed according to the set AF control mode.

  A sequence of photographing processing using flash auxiliary light in the second embodiment will be described with reference to the flowchart of FIG. In addition, since the process similar to FIG. 3 is performed about the step of the same number as the number in FIG. 3, detailed description is abbreviate | omitted. Further, FIG. 8 will be described with respect to processing when continuous flash photography is performed.

  First, in step S801, when the camera operation is started, the camera microcomputer 126 resets a counter n that counts the number of continuous shootings to zero. The counter n is counted every time continuous shooting is performed, and is reset to 0 even when the release switch is turned off. In step S301, when SW1 is pressed and the photographing process is started, the process proceeds to step S802. In step S802, the camera microcomputer 126 confirms whether or not the counter n that counts the number of continuous photographing is 0. If the counter n is 0, the process proceeds to step S803. On the other hand, if the counter n is not 0, that is, if continuous shooting is in progress, the process proceeds to step S303.

  Here, during continuous shooting (second and subsequent shooting), if the set AF control mode is the one-shot AF mode, the focus detection process is not performed because the previous AF result is used. In addition, the auxiliary light is not emitted in this embodiment when either the AI servo AF mode or the AI focus AF mode is set. Therefore, in step S303, the camera microcomputer 126 instructs the flash microcomputer 220 to set the light emission permission voltage level to M via the flash communication terminal 125. On the other hand, in step S803, the camera microcomputer 126 determines whether the set AF control mode is the AI servo AF mode.

  If the set AF control mode is the AI servo AF mode, the process proceeds to step S303 because no auxiliary light is emitted. In the AI servo AF mode, the auxiliary light is not emitted when the AI servo AF mode is set, because focus detection is repeatedly performed until a shooting instruction is issued during the AI servo AF mode. This is because the auxiliary light has to be irradiated every time. If auxiliary light is emitted every time focus detection is performed repeatedly, the battery is consumed very much and the number of times light can be emitted during photographing is reduced. For this reason, in this embodiment, when the AI servo AF mode is set, the auxiliary light is not irradiated regardless of the number of continuous photographing.

  On the other hand, when the set AF control mode is the one-shot AF mode, the focus detection process must be performed and the auxiliary light is emitted because the previous AF result cannot be used during the first shooting in continuous shooting. there is a possibility. Therefore, the process proceeds to step S304. In addition, when the set AF control mode is the AI focus AF mode, there is a possibility that auxiliary light may be emitted because the focus detection process similar to the one-shot AF mode is performed at the time of the first shooting in the continuous shooting. Therefore, the process proceeds to step S304.

  Then, the same photographing process as in the first embodiment is performed until S321, and then in S804, the camera microcomputer 126 counts up n for counting the number of continuous photographing, and returns to Step S301. Thereafter, the same operation is repeated.

  As described above, in the present embodiment, when continuous flash photography is performed, auxiliary light may be emitted in the AF control mode only during the first photography, so that the AF control mode in which the emission permission voltage level is set is set. Changed accordingly.

  In this embodiment, the focus detection process is executed by pressing the release switch. However, the image pickup apparatus is provided with operation means (AF button) for executing the focus detection process in addition to the release switch. Can adapt. For example, when the AF button is pressed, the AF lock state is set, and the processing of the light emission permission voltage level may be performed as in the case where the release switch is continuously pressed.

  As described above, in the present embodiment, the light emission permission voltage level of light emission (auxiliary light) for focus detection and light emission for shooting (preliminary light emission, main light emission) can be changed according to the AF control mode. It is said. Further, when the photographing process is continuously performed, the light emission permission voltage level can be changed depending on whether the first photographing or the second and subsequent photographing.

  For this reason, it is possible to shorten the interval between continuous strobe flash photography, and it is possible to take pictures at a timing intended by the photographer.

  In the above-described two embodiments, the strobe photographing system has a configuration in which the imaging device and the strobe device are separate devices, but the strobe device is built in the imaging device body regardless of such a configuration. Even the configuration can be adapted.

  In addition, even if the imaging device and the strobe device are separate devices and the strobe device is used as a slave strobe without being attached to the imaging device, optical communication or the like is performed between the imaging device and the strobe device. Thus, the present invention can be applied.

  Further, the lens unit may not be detachable and may be integrated with the imaging device.

  In addition, although the light emission permission voltage level is provided in three stages, that is, the auxiliary light emission permission level, the preliminary light emission permission level, and the main light emission permission level, it is not limited to this, and if at least the auxiliary light emission permission level is provided, Good.

  3 and 8, the processing according to the present invention may be performed by the flash microcomputer 220 instead of the camera microcomputer 126. For example, based on the information received from the camera microcomputer 126 via the strobe communication terminal 125 in step S302 in FIG. 3, it is determined whether or not the focus detection mode is a mode using auxiliary light, and light emission is permitted based on the determination result. What is necessary is just to set a voltage level.

1 is a block diagram showing a configuration of a flash photographing system according to a first embodiment of the present invention. 1 is a block diagram showing the configuration of a strobe device according to a first embodiment of the present invention. The flowchart which shows the imaging | photography process in the 1st Embodiment of this invention. The flowchart which shows the flash charge process in the 1st Embodiment of this invention The flowchart which shows the focus detection process in the 1st Embodiment of this invention. The flowchart which shows the focus detection process using the auxiliary light in the 1st Embodiment of this invention. The figure showing the light emission waveform at the time of the imaging | photography process in the 1st Embodiment of this invention, and the change of the charging voltage of a main capacitor | condenser The flowchart which shows the imaging | photography process in the 2nd Embodiment of this invention.

DESCRIPTION OF SYMBOLS 100 Digital camera 101 Lens unit 102 Quick return mirror 103 Shutter 104 Optical filter 105 Image pick-up element 106 A / D converter 107 Image processing circuit 108 Timing generation circuit 109 Display control circuit 110 Display part 111 Memory control circuit 112 Image display memory 113 Memory 114 Compression / decompression circuit 115 Shutter control circuit 116 Mirror control circuit 117 Distance measurement control circuit 118 Photometry control circuit 119 Non-volatile memory 120 Release switch 121 Menu operation switch 122 Power supply control circuit 123 Recording medium control circuit 124 Connector 125 Strobe communication terminal 126 Camera microcomputer 200 Strobe Device 201 Battery 202 Booster Circuit 203 Main Capacitor 204 Divider Resistor 205 Divider Resistor 206 Discharge Tube 207 Trigger generation circuit 208 Light emission control circuit 209 Data selector 210 Comparator 211 Comparator 212 Photometry circuit 213 Integration circuit 214 Photodiode 215 Photodiode 216 Display unit 217 Possible display LED
218 Dimmable LED
220 Strobe Microcomputer 300 Recording Medium 301 Connector 302 Recording Unit Control Circuit 303 Recording Unit

Claims (15)

A light emitting means for emitting light using electric energy charged in the capacitor;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
Focus detection means for detecting the focus of the subject;
A light emission control means for allowing the light emission means to emit light when a charge voltage of the capacitor detected by the charge voltage detection means is equal to or higher than a predetermined voltage;
The light emission control unit sets a first predetermined voltage as the predetermined voltage when the light emission for the focus detection is permitted, and the first voltage as the predetermined voltage when the light emission for photographing is permitted. A second predetermined voltage that is lower than the predetermined voltage is set.   The light emission control unit sets the first predetermined voltage as the predetermined voltage until light emission for the focus detection is performed, and the light emission control unit sets the predetermined voltage as the predetermined voltage after performing light emission for the focus detection. The imaging apparatus according to claim 1, wherein a second predetermined voltage is set. Determining means for determining whether to perform light emission for focus detection;
The said light emission control means sets the said 2nd predetermined voltage as said predetermined voltage, when it is judged that the light emission for the said focus detection is not performed by the said judgment means. The imaging device described. It has a mode to adjust the focus automatically and a mode to adjust the focus manually.
The imaging apparatus according to claim 3, wherein the determination unit determines that light emission for the focus detection is not performed when the manual focus adjustment mode is set. The automatic focus adjustment mode includes a first control mode in which the focus detection is performed once during the shooting preparation operation, and a first control mode in which the focus detection is repeatedly performed during the shooting preparation operation. There are two control modes,
The imaging apparatus according to claim 4, wherein the determination unit determines that light emission for the focus detection is not performed when the second control mode is set. Photometric means for determining the brightness of the subject;
The imaging apparatus according to claim 3, wherein the determination unit determines whether to perform light emission for the focus detection based on a photometric result of the photometry unit.   7. The voltage according to claim 1, wherein the first predetermined voltage is a voltage obtained by adding a voltage equal to or greater than a voltage drop amount of the capacitor due to light emission for focus detection to the second predetermined voltage. The imaging device according to any one of the above. The second predetermined voltage is a voltage set as the predetermined voltage when preliminary light emission for photographing is permitted,
The light emission control means sets a third predetermined voltage, which is a voltage lower than the second predetermined voltage, as the predetermined voltage when main light emission for photographing is permitted. 8. The imaging device according to any one of items 7.   The imaging apparatus according to claim 8, wherein the light emission control unit sets the third predetermined voltage as the predetermined voltage after the preliminary light emission is performed.   The second predetermined voltage is a voltage obtained by adding a voltage equal to or greater than a voltage drop amount of the capacitor due to the preliminary light emission to the third predetermined voltage, and the third predetermined voltage is the capacitor according to the main light emission. The image pickup apparatus according to claim 8, wherein the voltage is equal to or greater than a voltage drop amount.   The light emission control means determines that the light emission for the focus detection is performed by the determination means, and when the preliminary light emission is not performed, the first light emission control means until the light emission for the focus detection is performed. 11. The imaging apparatus according to claim 8, wherein a fourth predetermined voltage lower than a predetermined voltage and higher than the third predetermined voltage is set.   12. The voltage according to claim 11, wherein the fourth predetermined voltage is a voltage obtained by adding a voltage equal to or greater than a voltage drop amount of the capacitor due to light emission for focus detection to the third predetermined voltage. Imaging device. A light emitting means for emitting light using electric energy charged in the capacitor;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
Focus detection means for detecting the focus of the subject;
A light emission control means for allowing the light emission means to emit light when a charge voltage of the capacitor detected by the charge voltage detection means is equal to or higher than a predetermined voltage;
The light emission control unit sets a first predetermined voltage as the predetermined voltage when allowing light emission for focus detection, and sets the first voltage as the predetermined voltage when allowing preliminary light emission for photographing. When a second predetermined voltage that is lower than a predetermined voltage of 1 is set and main light emission for photography is permitted, a third predetermined voltage that is lower than the second predetermined voltage is used as the predetermined voltage. An image pickup apparatus characterized by setting. A strobe device that can be attached to and detached from an imaging device,
A light emitting means for emitting light using electric energy charged in the capacitor;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
A light emission control means for allowing the light emission means to emit light when a charge voltage of the capacitor detected by the charge voltage detection means is equal to or higher than a predetermined voltage;
The light emission control unit sets a first predetermined voltage as the predetermined voltage when allowing light emission for focus detection by the attached imaging device, and emits light for photographing by the attached imaging device. When permitted, a strobe device is characterized in that a second predetermined voltage that is lower than the first predetermined voltage is set as the predetermined voltage. A strobe photographing system having an imaging device and a strobe device,
A light emitting means for emitting light using electric energy charged in the capacitor;
Charging voltage detecting means for detecting a charging voltage of the capacitor;
Focus detection means for detecting the focus of the subject;
A light emission control means for allowing the light emission means to emit light when a charge voltage of the capacitor detected by the charge voltage detection means is equal to or higher than a predetermined voltage;
The light emission control unit sets a first predetermined voltage as the predetermined voltage when the light emission for the focus detection is permitted, and the first voltage as the predetermined voltage when the light emission for photographing is permitted. And a second predetermined voltage that is lower than the predetermined voltage.