JP2009122523A - Flash light device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flash light device illuminating an object optimally in consideration of a distance to the object even when the flash light device is installed away from a camera. <P>SOLUTION: A light emitting part 111 of an external flash light device 100 includes a distance measuring circuit 116. S2μcom 102 computes light emitting guide number for actual flashing based on the distance from the external flash light device 100 to the object which is computed based on outputs of the distance measuring circuit 116 and an F value and the correction factor transmitted by radio communication from the camera 200. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a strobe device that is disposed away from a camera and can emit light in synchronization with the main light emission of a strobe device built in or connected to the camera.

  2. Description of the Related Art Conventionally, there is known a wireless strobe system that controls light emission of a strobe device as an auxiliary illumination device of an imaging device by wireless communication from another device that is remotely located with respect to the strobe device. In photography using such a strobe system, lighting that erases shadows behind the subject or intentionally shades the subject can be freely performed.

As a proposal regarding the above-described wireless strobe system, for example, in Patent Document 1, information on light emission timing and light emission amount from a camera to a wireless strobe device using light emission other than exposure light emission (for example, pre-light emission) in a strobe device included in the camera. By transmitting this, it is possible to control the light emission amount and light emission timing of the wireless strobe device on the camera side.
JP-A-5-93944

  Here, in the method of Patent Document 1, communication of the light emission amount of the wireless strobe device is performed, but this light emission amount is calculated on the camera side. The light emission amount is calculated from the distance from the camera to the subject. In other words, the amount of light emission is not determined in consideration of the distance between the subject and the wireless strobe device, so that when the distance between the camera and the wireless strobe device is far away, optimal illumination is not always possible. Not exclusively.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a strobe device that can perform optimal illumination in consideration of the distance to the subject even when installed at a position away from the camera. To do.

  In order to achieve the above object, a strobe device according to a first aspect of the present invention is a strobe device installed at a position distant from a camera and configured according to parameters input by wireless communication with the camera. Ranging means for detecting the distance from the strobe device to the subject, calculating means for calculating the amount of light emission from the parameters input by the wireless communication and the distance detected by the distance measuring means, and the calculated light emission And a light emitting means for emitting light in synchronization with the exposure of the camera.

  In order to achieve the above object, a strobe device according to a second aspect of the present invention communicates with a distance measuring means for detecting a distance to a subject in a direction in which a light emitting unit faces, at least with the camera. Acquired by communication means for receiving an aperture value, light emission means for emitting light in synchronization with the main light emission of a strobe device built in the camera or connected to the camera, and the distance detected by the distance measurement means and the communication. And calculating means for calculating the light emission amount of the light emitting means from the aperture value thus obtained.

  In order to achieve the above object, a strobe device according to a third aspect of the present invention includes a slave mode that emits light in synchronization with a main light emission of a strobe device built in the camera or connected to the camera, and the camera. In a strobe device having a main mode that emits light in synchronization with the exposure timing of the camera connected to the camera, a distance measuring unit that detects the distance to the subject, and wireless communication that communicates wirelessly with the camera in the slave mode Means, wired communication means for communicating with the camera in the main mode by wire, and light emission amount obtained from the distance detected by the distance measuring means and the aperture value of the camera when communicating with the camera wirelessly Light emission means that emits light at a light emission amount instructed from the camera when communicating with the camera by wire Characterized by comprising.

  According to the present invention, it is possible to provide a strobe device that can perform optimal illumination in consideration of the distance to a subject even when installed at a position away from the camera.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an external strobe device as an example of a strobe device according to an embodiment of the present invention. An external strobe device 100 shown in FIG. 1 includes a strobe body 101 and a light emitting unit 111. The light emitting unit 111 is rotatably attached to the strobe body 101. The user can change the direction of the light emitting unit 111, that is, the light emission direction of the strobe light, by rotating the light emitting unit 111 in the vertical and horizontal directions.

  A communication connector 107 is provided at the bottom of the strobe body 101. Here, the external strobe device 100 can be used by being connected to the camera via the communication connector 107 or can be used by being remotely arranged with respect to the camera. When the external strobe device 100 is attached to the camera and used, the external strobe device 100 is attached to the camera via the communication connector 107. In this case, the external strobe device 100 is communicatively connected to the camera via the communication connector 107 and emits light according to control from the camera. On the other hand, when the external strobe device 100 is used away from the camera, the communication connector 107 is attached to the tripod 108. In this case, the external strobe device 100 operates as a wireless strobe device that emits light in synchronization with a command from the camera.

  Hereinafter, an operation mode when the external strobe device 100 is operated as a wireless strobe device is referred to as a slave mode, and an operation mode when the external strobe device 100 is used while attached to a camera is referred to as a main mode.

  The strobe main body 101 includes a strobe control microcomputer (S2 μcom) 102, an operation unit 103, a wireless signal receiving unit 104, a charging voltage detection circuit 105, and a display unit 106.

  S2 μcom 102 controls the overall operation of the external strobe device 100 such as strobe light emission control in the light emitting unit 111 and display control of the display unit 106. In the present embodiment, the S2 μcom 102 measures the distance between the external flash device 100 and the subject based on a signal from the distance measuring circuit 116 provided in the light emitting unit 111, and the light emitting unit 111 emits strobe light. It also has a function as a calculation means for calculating the amount of emitted light.

  The operation unit 103 sets the operation mode of the external flash device 100, whether to use the external flash device 100 in the slave mode, and a group when using the external flash device 100 set in a plurality of slave modes. And an operation unit such as a power switch for switching on / off the power supply of the external strobe device 100. Here, when a plurality of external flash devices are used in the slave mode, by setting a group, the external flash devices belonging to the same group are controlled to emit the same light. In addition, by setting the communication channel, the same information is received by the external flash device in which the same communication channel is set.

  The wireless signal receiving unit 104 receives various types of information from the camera by wireless communication when the external flash device 100 is used in the slave mode. Note that the method of wireless communication with the camera is not particularly limited, but in the following description, an example will be described in which communication is performed by light emission with a small amount of light using a strobe device of the camera.

  The charging voltage detection circuit 105 detects the charging voltage in the charging circuit 112 of the light emitting unit 111, and notifies the detected charging voltage to S2μcom102. S2 μcom 102 determines whether energy necessary for strobe light emission is accumulated in the light emission circuit 113 based on the charge voltage detected by the charge voltage detection circuit 105.

  The display unit 106 displays various information related to the external flash device 100 such as the operation mode of the external flash device 100 and the charging state of the charging circuit 112.

  The light emitting unit 111 includes a charging circuit 112, a light emitting circuit 113, an arc tube 114, a reflector 115, and a distance measuring circuit 116.

  The charging circuit 112 includes a power source, a charging capacitor, and the like, and accumulates energy necessary for strobe light emission. In response to the light emission instruction from S2μcom 102, the light emitting circuit 113 causes the light emitting tube 114 to emit light using the energy accumulated in the capacitor of the charging circuit 112. The arc tube 114 is, for example, a xenon (Xe) tube, and emits strobe light in accordance with a signal from the light emitting circuit 113. The reflector 115 condenses the strobe light from the arc tube 114 forward.

  The distance measuring circuit 116 is composed of, for example, an active distance measuring circuit, measures the distance from the external strobe device 100 to the subject, and notifies the Sμcom 102 of the distance measurement result. The active distance measuring circuit includes a light projecting unit including a light projecting lens and an infrared LED, and a light receiving unit including a light receiving lens and a photodiode array. Based on the light receiving position when the light projected from the subject (not shown) of the light projected from the light projecting unit is received by the light receiving unit, the distance between the light projecting unit and the light receiving unit, and the focal length of the lens, The distance to the subject is measured by the principle of distance measurement.

  Here, by providing the distance measuring circuit 116 in the light emitting unit 111, it is possible to accurately measure the distance to the subject existing in the direction in which the light emitting unit 111 faces.

  FIG. 2 is a block diagram showing a configuration of a camera that constitutes the wireless strobe system according to the present embodiment together with the external strobe device 100.

  A camera 200 shown in FIG. 2 includes a lens barrel 201 and a camera body 210. The camera main body 210 is provided with a communication connector 240, and the external strobe device 100 is used as a strobe device of the camera 200 by connecting the communication connector 107 of the external strobe device 100 to the communication connector 240. Is possible.

  The lens barrel 201 is configured to be detachable from the camera body 210 via a lens mount (not shown) provided on the front surface of the camera body 210. The lens barrel 201 includes a photographing lens 202, a diaphragm 203, a lens driving mechanism 204, a diaphragm driving mechanism 205, and a lens control microcomputer (hereinafter abbreviated as Lμcom) 206.

  The photographic lens 202 is driven in the optical axis direction by a DC motor (not shown) existing in the lens driving mechanism 204, collects a light beam from a subject (not shown), and makes it enter the camera body 210. The diaphragm 203 is driven by a stepping motor (not shown) that exists in the diaphragm drive mechanism 205. The Lμcom 206 drives and controls each part in the lens barrel 201 such as the lens driving mechanism 204 and the aperture driving mechanism 205. This Lμcom 206 is electrically connected to a later-described body control microcomputer (hereinafter abbreviated as Bμcom) 231 via a communication connector 207, and is controlled in accordance with a command from Bμcom 231. Further, Lμcom 206 stores basic data such as a lens type, an open aperture value, and a focal length. These basic data are transmitted to the Bμcom 231 through communication with the camera body 210.

  On the other hand, the camera body 210 includes a reflection mirror 211, a mirror drive mechanism 212, a finder optical system, an AF movable mirror 215, an AF sensor unit 216, an AF sensor drive circuit 217, a shutter unit 218, and a shutter charge. Mechanism 219, shutter control circuit 220, imaging unit, dust filter driving circuit 224, temperature measurement circuit 225, imaging interface circuit 226, image processing controller 227, liquid crystal monitor 228, and buffer memory (SDRAM) 229 A recording medium 230, a Bμcom 231, a drive circuit 232, an auxiliary light LED 233, an operation display LCD 234, a camera operation switch (SW) 235, a power supply circuit 236, a battery 237, a photometry circuit 238, Non-volatile memory (EEPROM) 2 9, and a built-in flash unit.

  The reflection mirror 211 is formed of a half mirror at the center and is placed on the imaging optical path shown in FIG. Part of the luminous flux from the light is transmitted and part of the light is reflected. The reflection mirror 211 is driven by a mirror drive mechanism 212. When the reflection mirror 211 is retracted from the photographing optical path, a light beam from a subject (not shown) is passed in the direction of the shutter unit 218.

  The viewfinder optical system has a Porro prism 213 and an eyepiece lens 214. The Porro prism 213 turns an image based on the light beam reflected by the reflection mirror 211 into an erect image. The eyepiece 214 enlarges the image emitted from the Porro prism 213.

  The AF movable mirror 215 is disposed behind the half mirror portion of the reflection mirror 211 and operates independently of the reflection mirror 211. The AF movable mirror 215 guides the subject light flux that has passed through the half mirror portion of the reflection mirror 211 in the direction of the AF sensor unit 216. The AF sensor unit 216 is, for example, a TTL phase difference type AF sensor. The AF sensor driving circuit 217 is a circuit for driving and controlling the AF sensor unit 216.

  The shutter unit 218 is, for example, a focal plane type shutter disposed on the optical axis of the photographing lens 202 and behind the reflection mirror 211. The shutter charge mechanism 219 charges a spring that drives a front curtain and a rear curtain (not shown) constituting the shutter unit 218. The shutter control circuit 220 controls the movement of the front curtain and the rear curtain of the shutter unit 218 and exchanges a signal for controlling the opening / closing operation of the shutter with the Bμcom 231.

  The imaging unit includes an imaging element 221, a dustproof filter 222, and a piezoelectric element 223, and is a photoelectric conversion unit for photoelectrically converting a subject image that has passed through the shutter unit 218.

  The image sensor 221 is a CCD image sensor, for example, and converts the subject image that has passed through the shutter unit 218 into an electrical signal (image signal) by photoelectric conversion. That is, when the reflecting mirror 211 is retracted from the photographing optical path, the light flux that has passed through the photographing lens 202 and the diaphragm 203 is imaged on the imaging surface of the image sensor 221 and converted into an image signal.

  The dustproof filter 222 is made of a transparent member such as glass, for example, and prevents dust from adhering to the imaging surface of the imaging element 221. A piezoelectric element 223 for causing the dust filter 222 to vibrate at a predetermined vibration frequency is attached to the periphery of the dust filter 222. The piezoelectric element 223 has two electrodes and is driven by a dustproof filter driving circuit 224. The dust filter 222 is vibrated by vibrating the piezoelectric element 223 by the dust filter driving circuit 224. As a result, dust adhering to the surface of the dustproof filter 222 is removed.

  Here, the image sensor 221 and the piezoelectric element 223 are housed integrally in a case having the dust filter 222 as one surface. Thereby, adhesion of dust to the image sensor 221 can be reliably prevented.

  The temperature measurement circuit 225 measures the ambient temperature of the dustproof filter 222. Usually, the temperature affects the elastic correction coefficient of the glass material. That is, since the change in temperature becomes one of the factors that change the natural frequency of the dust filter 222, the ambient temperature is always measured when the dust filter 222 is vibrated. The temperature measurement point of the temperature measurement circuit 225 is preferably set in the vicinity of the vibration surface of the dust filter 222. As described above, by controlling the vibration of the dustproof filter 222 while considering the change in temperature, it is possible to always vibrate the dustproof filter 222 under optimum conditions.

  The imaging interface circuit 226 drives the imaging element 221 and processes an image signal obtained by the imaging element 221 so that the image processing controller 227 can perform image processing. The image processing controller 227 obtains image data by subjecting the image signal output from the imaging interface circuit 226 to image processing so as to be suitable for display and recording. The liquid crystal monitor 228 displays an image based on the image data processed by the image processing controller 227. The buffer memory (SDRAM) 229 is a temporary storage memory for various data such as image data. The buffer memory 229 is used as a work area when various types of image processing are performed on the image data. The recording medium 230 is an external recording medium such as various memory cards and an external hard disk drive (HDD) that can be attached to and detached from the camera body 210 via a camera interface (not shown).

  The Bμcom 231 controls each part in the camera body 210 such as the mirror drive mechanism 212, the AF sensor drive circuit 217, the shutter charge mechanism 219, the shutter control circuit 220, and the dustproof filter drive circuit 224. In addition, a drive circuit 232, an operation display LCD 234, a camera operation switch (SW) 235, and a power supply circuit 236 are connected to the Bμcom 231.

  The drive circuit 232 drives the auxiliary light LED 233. The auxiliary light LED 233 projects auxiliary light such as AF assistance to a subject (not shown). The operation display LCD 234 is an LCD for notifying the user of the operation state of the camera 200 by display output. The camera operation SW 235 is configured as a two-stage switch, for example, a release switch for instructing execution of a shooting operation (a 1R switch that operates when the release button is half-pressed and a 2R switch that operates when the release button is fully pressed. ), An operation switch group necessary for operating the camera 200, such as a mode change switch for switching between the photographing mode and the image display mode, and a power switch for switching on / off the power of the camera 200. The power supply circuit 236 converts the voltage of the battery 237 as a power supply into a voltage required by each unit of the camera 200 and supplies the converted voltage.

  The photometric circuit 238 performs photometric processing based on an electric signal of a photometric sensor (not shown) disposed in the vicinity of the Porro prism 213. The nonvolatile memory 239 stores predetermined control parameters necessary for camera control.

  Further, a built-in strobe unit is connected to Bμcom 231. The built-in strobe unit includes a charging circuit 241, a light emitting circuit 242, a light emitting tube 243, a reflector 244, and a charging voltage detection circuit 245.

  The charging circuit 241 has a charging capacitor therein, and charges the energy for strobe light emission using the power supply voltage generated by the power supply circuit 236. The light emitting circuit 242 causes the arc tube 243 to emit light using the charging voltage of the capacitor inside the charging circuit 241. The arc tube 243 is, for example, a xenon (Xe) tube, and emits strobe light in accordance with a signal from the light emitting circuit 242. The reflector 244 collects the strobe light from the arc tube 243 forward. The charging voltage detection circuit 245 detects the charging voltage of the charging circuit 241 and, when it is determined that the capacitor is sufficiently charged, stops the charging operation by the charging circuit 241 and determines that the capacitor is not sufficiently charged. In such a case, the charging operation of the charging circuit 241 is continued.

Hereinafter, operations of the external strobe device and the camera described above will be described.
First, the operation on the camera side will be described. FIG. 3 is a flowchart showing the main processing of the camera controlled by the Bμcom 231. When the battery 237 is loaded in the camera main body 210, the processing in FIG. 3 is started. First, Bμcom 231 performs initial setting (step S1). The initial setting includes, for example, reset processing of a register (not shown) in the Bμcom 231 and I / O port setting.

  After the initial setting, the Bμcom 231 determines whether the power switch of the camera operation SW 235 is turned on by a user operation (step S2). Thereafter, in the determination of step S2, the process waits until the power switch is turned on. On the other hand, when the power switch is turned on in the determination in step S2, the Bμcom 231 detects the operation state of the camera operation SW 235 (step S3). While the camera operation SW 235 is not operated, it waits. When the camera operation SW 235 is operated, the Bμcom 231 performs various mode change processes according to the operated switch (step S4). In this mode change process, in addition to setting various modes of the camera 200 itself, the user sets whether or not to shoot using the external strobe device 100 in the slave mode, and sets a plurality of external strobe devices in the slave mode. For example, it is possible to set the channel and group of each external strobe device used in the above, and to set various parameters necessary for calculating the light emission amount (light emission guide number). When the mode change process is performed, the result is displayed on the operation display LCD 234.

  After the mode change process, the Bμcom 231 determines whether the 1R switch included in the release switch of the camera operation SW 235 is turned on by a user operation (step S5). If it is determined in step S5 that the 1R switch has not been turned on, the process returns to step S2. On the other hand, when the 1R switch is turned on in the determination of step S5, the Bμcom 231 operates the AF sensor driving circuit 217 to perform distance measurement, and the photographing lens 202 necessary for focusing based on the distance measurement result. Is calculated (step S6). After that, the Bμcom 231 communicates with the Lμcom 206 to acquire the current lens position of the photographing lens 202. Then, the Bμcom 231 determines whether the acquired lens position is within the focusing range (step S7). If it is determined in step S7 that the lens position is not within the focusing range, the Bμcom 231 communicates with the Lμcom 206 to drive the photographing lens 202 in focus (step S8). Thereafter, the processes in steps S5 to S8 are repeated until the lens position of the photographic lens 202 is within the focusing range.

  If it is determined in step S7 that the lens position is within the in-focus range, the Bμcom 231 determines whether the 2R switch included in the release switch of the camera operation SW 235 is turned on by a user operation (step S9). If the 2R switch is not turned on in the determination in step S9, the Bμcom 231 determines whether the 1R switch remains on (step S10). If it is determined in step S10 that the 1R switch remains on, the process returns to step S9. On the other hand, if the 1R switch is turned off in the determination in step S10, the process returns to step S2.

  Further, when the 2R switch is turned on in the determination in step S9, the Bμcom 231 determines the exposure amount (aperture value and shutter speed necessary for making the exposure of the photographed image appropriate) according to the result of the photometric processing of the photometric circuit 238. Is calculated (step S11).

  Thereafter, the Bμcom 231 determines from the result of the photometry processing of the photometry circuit 238 or the like whether or not the strobe light needs to be emitted at the time of imaging (exposure) (step S12). If it is determined in step S12 that it is not necessary to emit strobe light, the Bμcom 231 performs a mirror up operation and a narrowing operation (step S13). That is, the Bμcom 231 controls the mirror driving mechanism 212 to retract the reflecting mirror 211 from the photographing optical path. Further, Bμcom 231 instructs Lμcom 206 to narrow down the diaphragm 203. In response to this, the Lμcom 206 controls the diaphragm drive mechanism 205 to narrow the diaphragm 203 in accordance with the diaphragm value calculated in step S11. After completing the mirror up operation and the narrowing-down operation, the Bμcom 231 executes an exposure (imaging) operation (step S14). That is, the Bμcom 231 controls the shutter control circuit 220 to operate the front curtain and rear curtain of the shutter unit 218 according to the shutter speed calculated in step S11. Thereby, the exposure of the image obtained through the image sensor 221 becomes appropriate.

  If it is determined in step S12 that strobe light emission is necessary, the Bμcom 231 determines whether to use the built-in strobe unit for strobe light emission (step S15). The built-in strobe unit is basically used to emit strobe light from the camera 200. However, when the external strobe device 100 is attached to the camera body 210 (determined by transmission / reception of a signal via the communication connector 240), the external strobe device 100 is used. Further, the user may be able to select which of the built-in flash unit and the external flash device 100 is used. This setting is performed in the mode change process in step S4. Furthermore, both the built-in strobe unit and the external strobe device 100 may be usable. However, in this case, either the built-in strobe unit or the external strobe device 100 attached to the camera body 210 is used as a strobe light source used for communication with an external strobe device 100 as a wireless strobe device described later. It is necessary to set whether to do it.

  When the built-in strobe unit is used in the determination in step S15, the Bμcom 231 determines whether the wireless strobe device is set to be used in the mode change process in step S4 (step S16).

  In step S16, when the wireless strobe device is used, the Bμcom 231 performs wireless communication with the external strobe device 100 as a wireless strobe device by causing the built-in strobe unit to emit light (step S17). Details of this wireless communication will be described later.

  After wireless communication is performed with the external strobe device 100 and various settings in the external strobe device 100 on the wireless strobe device side are completed, the Bμcom 231 performs a mirror up operation and a narrowing operation (step S18). After the mirror-up operation and the narrowing-down operation, the Bμcom 231 calculates the light emission amount (light emission guide number Gno) of the built-in strobe unit from the subject distance calculated by the output of the AF sensor unit 216 and the aperture value. The light emission guide number Gno can be obtained from Gno = Fno / L where the aperture value is Fno and the subject distance is L. After calculating the light emission amount, the Bμcom 231 instructs the built-in strobe unit to perform main light emission, and then executes an exposure (imaging) operation (step S19).

  If the wireless strobe device is not used in the determination of step S16, the Bμcom 231 skips the processing of step S17, transmits the light emission guide number Gno to the built-in strobe unit, and instructs the main flash. The exposure (imaging) operation is executed.

  If the built-in strobe unit is not used in the determination in step S15, the Bμcom 231 determines whether the wireless strobe device is set to be used in the mode change process in step S4 (step S20).

  In the determination of step S20, when using the wireless strobe device, the Bμcom 231 causes the external strobe device 100 mounted on the camera body 210 to emit light, and performs wireless communication with the external strobe device 100 on the wireless strobe device side. This is performed (step S21). After completing various settings in the external strobe device 100 on the wireless strobe device side, the Bμcom 231 performs a mirror up operation and a narrowing operation (step S22). After the mirror-up operation and the narrowing-down operation, the Bμcom 231 calculates the light emission amount (light emission guide number Gno) of the external strobe device 100 attached to the camera body 210. Then, the Bμcom 231 transmits the light emission guide number Gno to the external strobe device 100 mounted on the camera body 210 and instructs the start of the main light emission, and then executes an exposure (imaging) operation (step S23). ).

  In step S20, when the wireless strobe device is not used, the Bμcom 231 transmits a light emission guide number Gno as a light emission amount to the external strobe device 100 mounted on the camera body 210 (step S24). Next, the Bμcom 231 instructs the external strobe device 100 mounted on the camera main body 210 to start main light emission, and then performs an exposure (imaging) operation.

  After the exposure (imaging) operation is completed by any one of steps S14, S19, or S23, the Bμcom 231 performs a mirror down operation, an aperture opening operation, and a shutter charge operation (step S25). That is, the Bμcom 231 controls the mirror driving mechanism 212 to return the reflecting mirror 211 to a position on the photographing optical path. Bμcom 231 instructs Lμcom 206 to open the diaphragm 203. In response to this, the Lμcom 206 controls the aperture driving mechanism 205 to open the aperture 203. Further, the Bμcom 231 controls the shutter charge mechanism 219 to charge a spring that drives the front curtain and the rear curtain of the shutter unit 218.

  Thereafter, the Bμcom 231 instructs the image processing controller 227 to read out the image signal (step S26). Thereafter, the Bμcom 231 instructs the image processing controller 227 to perform image processing (step S27). After the image processing ends, the Bμcom 231 instructs the image processing controller 227 to record the processed image data on the recording medium 230 (step S28). Thereafter, the process returns to step S1.

  Next, the operation on the external strobe device side will be described. FIG. 4 is a flowchart showing the main processing of the external strobe device controlled by S2μcom102. When a battery (not shown) is loaded in the strobe body 101 of the external strobe device 100, the processing of FIG. First, S2μcom 102 performs initial setting (step S101). The initial setting is, for example, reset processing of a register (not shown) in the S2μcom 102, setting of an I / O port, or the like.

  After the initial setting, S2μcom 102 determines whether the power switch of the operation unit 103 is turned on by a user operation (step S102). Thereafter, in the determination of step S102, the process waits until the power switch is turned on. On the other hand, if it is determined in step S102 that the power switch is turned on, the S2μcom 102 checks the communication method with the camera 200 (step S103). This process is a process for communicating with the Bμcom 231 of the camera body 210 via the communication connector 107.

  From the result of communication with Bμcom 231, S2μcom 102 determines whether the current communication method of external strobe device 100 is wireless communication (step S104). In the determination in step S104, if there is no response from the Bμcom 231 as a result of the communication in step S103, it is determined that the external strobe device 100 is not attached to the camera body 210, that is, is wireless communication. On the other hand, if there is a response from the Bμcom 231, it is determined that the external strobe device 100 is attached to the camera body 210, that is, is wired communication.

  If it is determined in step S104 that the communication method is wireless communication, the external flash device 100 operates in the slave mode. In this case, the S2μcom 102 detects the operation state of the operation unit 103 (step S105). When the operation unit 103 is operated, the Sμcom 102 performs various mode change processes according to the operation state of the operation unit 103 (step S106). In this mode change process, the user can set channels and groups when the external strobe device 100 is used as a wireless strobe device. When the mode change process is performed, the result is displayed on the display unit 106.

  Next, S2 μcom 102 determines from the charging voltage detected by the charging voltage detection circuit 105 whether charging of the charging capacitor in the charging circuit 112 has been completed (step S107). If it is determined in step S107 that charging has not been completed, S2μcom 102 causes the capacitor in charging circuit 112 to be charged (step S108). On the other hand, when the charging is completed in the determination in step S107, S2μcom 102 skips the process in step S108.

  Thereafter, S2 μcom 102 calculates the distance from the external strobe device 100 to the subject based on the output of the distance measuring circuit 116 (step S109). After calculating the subject distance, the S2μcom 102 determines whether wireless communication from the camera 200 has been started (step S110). If it is determined in step S110 that wireless communication from the camera 200 has not started, the process returns to step S102. On the other hand, when the wireless communication from the camera 200 is started in the determination in step S110, the S2μcom 102 receives the data transmitted from the camera 200 via the wireless signal receiving unit 104 (step S111).

  After receiving data from the camera 200, the S2μcom 102 calculates a light emission amount (light emission guide number Gno) according to a command indicated by the data received from the camera 200 (step S112). Thereafter, S2μcom 102 determines whether a communication end signal is received from camera 200 (step S113). Thereafter, in step S113, the process waits until a communication end signal is received from the camera 200. When the communication end signal is received from the camera 200 in the determination in step S113, the S2μcom 102 waits for the main light emission of the camera 200, and issues a light emission instruction to the light emission circuit 113 when the main light emission of the camera 200 is performed. (Step S114). As a result, strobe emission is performed by the external strobe device 100 that is remotely located from the camera 200.

  If it is determined in step S104 that the communication method is wired communication, the external flash device 100 operates as the main mode. In this case, the S2μcom 102 detects the operation state of the operation unit 103 (step S115). When the operation unit 103 is operated, the Sμcom 102 performs various mode change processes according to the operation state of the operation unit 103 (step S116). When the mode change process is performed, the result is displayed on the display unit 106.

  Next, S2 μcom 102 determines from the charging voltage detected by the charging voltage detection circuit 105 whether charging of the charging capacitor in the charging circuit 112 has been completed (step S117). If it is determined in step S117 that charging has not been completed, S2μcom 102 causes the capacitor in charging circuit 112 to be charged (step S118). On the other hand, if the charging is completed in the determination in step S117, S2μcom 102 skips the process in step S118.

  Thereafter, the S2μcom 102 receives the light emission guide number Gno as the light emission amount from the camera body 210 via the communication connector 107 (step S119). After receiving the light emission guide number Gno from the camera 200, the S2μcom 102 determines whether or not a light emission start instruction is received from the camera 200 (step S120). Thereafter, in the determination in step S120, the process waits until a light emission start instruction is received from the camera 200. In the determination in step S120, when a light emission start instruction is received from the camera 200, S2μcom 102 issues a light emission instruction to the light emission circuit 113 (step S121). As a result, strobe light emission is performed by the external strobe device 100 attached to the camera body 210.

  Next, wireless communication between the external flash device 100 and the camera 200 will be further described. In this embodiment, as an example, wireless communication between the external strobe device 100 and the camera 200 is performed using strobe light emission from the camera 200. FIG. 5 is a diagram illustrating a relationship between light emission of the camera 200 and data transmitted thereby.

  As shown in FIG. 5, the camera 200 performs light emission of nine small amounts of light, transmits various data, and performs main light emission at the tenth time. The external strobe device 100 as a wireless strobe device performs various settings necessary for light emission according to the first to ninth light emission from the camera 200, and performs main light emission in synchronization with the main light emission of the camera 200.

  First, the first light emission is for indicating the start of communication. When the first light emission is received, the Sμcom 102 of the external strobe device 100 determines that wireless communication has started. Subsequently, the second light emission is performed after waiting for a predetermined time (100 ms in the example in the figure) from the first light emission.

  The second to third light emission is a transmission period of data indicating a channel, and the channel data is designated by the light emission interval between the second light emission and the third light emission. FIG. 6 is a diagram showing an example of the relationship between the light emission interval and the data value indicated thereby. In the example shown in FIG. 6, the second to third light emission indicating the channel data is performed between 10 ms and 25 ms, and takes a different value every 5 ms. In this case, the channel can take four types of values at a light emission interval of 10 ms to 25 ms. The Sμcom 102 measures the second to third emission intervals and identifies the channel data value. Similarly, for the subsequent light emission, the data interval is identified by measuring the light emission interval.

  If the channel indicated by the received data is different from the channel set in the mode change process in step S106, the data transmitted thereafter is ignored.

  The third to fourth light emission is a data transmission period indicating a group, and the group data is designated by the light emission interval between the third light emission and the fourth light emission. In the example shown in FIG. 6, the third to fourth light emission indicating the group data is performed between 10 ms and 25 ms, and becomes a different value every 5 ms. In this case, the group can take four types of values at a light emission interval of 10 ms to 25 ms. If the group indicated by the received data is different from the group set in the mode change process in step S106, the data transmitted thereafter is ignored.

  The fourth to fifth light emission is a data transmission period indicating a command for determining the light emission amount of the wireless strobe device during the main light emission, and the command data is designated by the light emission interval between the fourth light emission and the fifth light emission. Is done. In the example shown in FIG. 6, the fourth to fifth light emission indicating the command data is performed between 10 ms and 20 ms, and becomes a different value every 5 ms. In this case, the command can take three types of values at a light emission interval of 10 ms to 20 ms.

FIG. 7 is a diagram illustrating an example of the relationship between command values and their contents.
In the example shown in FIG. 7, when the value of the command is 0, the light emission amount (light emission guide number) obtained from the aperture value obtained by the camera 200 and the subject distance detected based on the output of the distance measuring circuit 116. ) Is multiplied by a correction coefficient indicating the light quantity ratio of the external light, the external strobe device 100, and the camera 200, and the sensitivity of the image sensor 221 is obtained. Here, when the sensitivity of the image sensor 221 is high, the light emission amount of the external strobe device 100 is reduced. On the other hand, when the sensitivity of the image sensor 221 is low, the light emission amount of the external strobe device 100 is increased. When such a command value is 0, the aperture value is set for the fifth to sixth emission, the correction coefficient is set for the sixth to seventh emission, and the sensitivity of the image sensor 221 is set for the seventh to eighth emission. Sent as a parameter.

  FIG. 8 is a diagram showing an example of the relationship between the light emission intervals of the fifth to sixth light emission when the command value is 0 and the aperture value indicated thereby. In the example shown in FIG. 8, the fifth to sixth light emission indicating the aperture value is performed between 10 ms and 55 ms, and becomes a different value every 5 ms. In this case, the aperture value can take ten values with a light emission interval of 10 ms to 55 ms.

  FIG. 9 is a diagram illustrating an example of the relationship between the emission intervals of the sixth to seventh emission when the command value is 0 and the correction coefficient indicated thereby. In the example shown in FIG. 9, the sixth to seventh light emission indicating the correction coefficient is performed between 10 ms and 30 ms, and becomes a different value every 5 ms. In this case, the correction coefficient can take 5 types of values at a light emission interval of 10 ms to 30 ms.

  Here, the correction coefficient is a value that can be set by the user in the mode change process in the camera 200, but the user need not set it. In this case, a predetermined value (for example, 1/4) is transmitted.

  FIG. 10 is a diagram illustrating an example of the relationship between the light emission intervals of the seventh to eighth light emission and the sensitivity of the image sensor 221 indicated thereby when the command value is zero. In the example shown in FIG. 10, the seventh to eighth light emission indicating the sensitivity is performed between 10 ms and 40 ms, and becomes a different value every 5 ms. In this case, the sensitivity can take seven values with a light emission interval of 10 ms to 40 ms.

  In the example shown in FIG. 7, when the value of the command is 1, the light emission amount (light emission guide number) instructed by the camera 200 is set as the light emission amount during the main light emission. In this case, the light emission guide number Gno is transmitted by the fifth to sixth light emission. It is not necessary to emit light for the 7th and 8th times, but after the 6th light emission, the 7th and 8th light emission are performed after a 6th light emission so that the light emission after the 9th time can be identified. Also good.

  FIG. 11 is a diagram showing an example of the relationship between the light emission intervals of the fifth to sixth light emission and the light emission guide number indicated thereby when the command value is 1. In FIG. In the example shown in FIG. 11, the fifth to sixth light emission indicating the light emission guide number is performed between 10 ms and 35 ms, and becomes a different value every 5 ms. In this case, the light emission guide number can take 6 types of values at a light emission interval of 10 ms to 35 ms.

  In the example shown in FIG. 7, when the value of the command is 2, the current light emission amount (light emission guide number) is determined based on the previously determined light emission amount. In this case, the sign of the light emission amount difference from the previous light emission amount is transmitted by the fifth to sixth light emission, and the absolute value of the light emission amount difference is transmitted by the sixth to seventh light emission. Although it is not necessary to perform the light emission for the eighth time, the eighth light emission may be performed with a predetermined time after the seventh light emission so that the light emission after the ninth time can be identified.

  FIG. 12 is a diagram showing an example of the relationship between the emission intervals of the fifth to sixth emission when the command value is 2, and the sign of the difference in emission amount indicated thereby. In the example shown in FIG. 12, the fifth to sixth light emission indicating the sign of the light emission amount difference is performed between 10 ms and 15 ms. In the example of FIG. 12, the sign of the difference is positive when the light emission interval is 10 ms, and the sign of the difference is negative when the light emission interval is 15 ms.

  FIG. 13 is a diagram showing an example of the relationship between the emission intervals of the sixth to seventh emission when the command value is 2 and the absolute value of the difference in emission amount indicated thereby. In the example shown in FIG. 13, the sixth to seventh light emission indicating ΔGv indicating the absolute value of the light emission amount difference is performed between 10 ms and 25 ms, and becomes a different value every 5 ms. In this case, ΔGv can take four values with a light emission interval of 10 ms to 25 ms. In the example of FIG. 13, the light emission amount difference is represented by an apex value.

  With the above fourth to eighth light emission, all parameters necessary for calculating the light emission amount are transmitted to the external flash device 100. In response to this, the S2μcom 102 of the external strobe device 100 calculates the light emission amount during the main light emission. After the calculation, the camera 200 waits for the ninth and subsequent light emission. The ninth light emission from the camera 200 is a light emission for indicating the end of communication. When the ninth light emission is received, the S2μcom 102 of the external strobe device 100 determines that the wireless communication is terminated. Then, the light emission circuit 113 is instructed to emit light in synchronization with the main light emission of the camera 200 that is the 10th light emission thereafter.

  As described above, according to this embodiment, by providing the distance measuring circuit 116 in the external strobe device 100 used as the wireless strobe device, it is possible to measure the distance from the external strobe device 100 to the subject. is there. As a result, the external strobe device 100 can emit light with a more appropriate amount of light emission.

  Also, by providing the distance measuring circuit 116 on the rotatable light emitting unit 111 side, it is possible to measure the subject distance in the direction in which the light emitting unit 111 is actually facing, and to calculate a more accurate light emission amount. Is possible.

  In addition, by transmitting a correction coefficient for correcting the light emission amount by communication from the camera 200, it is appropriate to consider the influence of external light, the influence of light emission by the camera 200, and the influence of light emission of the external strobe device 100. It is possible to perform strobe light emission so that proper exposure can be obtained.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are naturally possible within the scope of the gist of the present invention.

  For example, the data transmission method shown in FIG. 5 is an example and can be changed as appropriate. In addition, it is possible to use infrared communication or the like without using strobe light for wireless communication.

  Data transmitted by wireless communication is also an example, and can be changed as appropriate depending on the specifications of the camera 200 and the external flash device 100.

  Further, the above-described embodiments include various stages of the invention, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some configuration requirements are deleted from all the configuration requirements shown in the embodiment, the above-described problem can be solved, and this configuration requirement is deleted when the above-described effects can be obtained. The configuration can also be extracted as an invention.

1 is a diagram illustrating a configuration of an external strobe device as an example of a strobe device according to an embodiment of the present invention. FIG. It is a block diagram which shows the structure of the camera which concerns on one Embodiment of this invention. It is the flowchart shown about the main process of the camera. It is the flowchart shown about the main process of an external strobe device. It is a figure which shows the relationship between the light emission of a camera, and the data transmitted by it. It is the figure which showed an example of the relationship between the light emission interval and the value of the data shown by it. It is a figure which shows an example of the relationship between the value of a command, and its content. It is the figure which showed an example of the relationship between the light emission interval of the 5th-6th light emission in case the value of a command is 0, and the aperture value shown by it. It is the figure which showed an example of the relationship between the light emission interval of the 6th-7th light emission in case the value of a command is 0, and the correction coefficient shown by it. It is the figure which showed an example of the relationship between the light emission interval of the 7th-8th light emission in case the value of a command is 0, and the sensitivity of the image pick-up element shown by it. It is the figure which showed an example of the relationship between the light emission interval of the 5th-6th light emission in case the value of a command is 1, and the light emission guide number shown by it. It is the figure which showed an example of the relationship between the light emission interval of the 5th-6th light emission in case the value of a command is 2, and the code | symbol of the light emission amount difference shown by it. It is the figure which showed an example of the relationship between the light emission interval of the 6th-7th light emission in case the value of a command is 2, and the absolute value of the light emission amount difference shown by it.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... External strobe device, 101 ... Strobe main body, 102 ... Strobe control microcomputer (S2μcom), 103 ... Operation part, 104 ... Wireless signal receiving part, 105 ... Charge voltage detection circuit, 106 ... Display part, 107 ... Communication connector , 108 ... tripod, 111 ... light emitting section, 112 ... charging circuit, 113 ... light emitting circuit, 114 ... arc tube, 115 ... reflector, 116 ... distance measuring circuit, 200 ... camera, 201 ... lens barrel, 202 ... photographing lens , 203 ... Aperture, 204 ... Lens drive mechanism, 205 ... Aperture drive mechanism, 206 ... Lens control microcomputer (Lμcom), 207 ... Communication connector, 210 ... Camera body, 211 ... Reflection mirror, 212 ... Mirror drive mechanism, 213 ... Porro prism, 214 ... Eyepiece, 215 ... AF movable mirror, 216 ... AF center Sensor unit, 217... AF sensor drive circuit, 218. Shutter unit, 219. Shutter charge mechanism, 220. Shutter control circuit, 221... Image sensor, 222. ... Temperature measurement circuit, 226 ... Imaging interface circuit, 227 ... Image processing controller, 228 ... Liquid crystal monitor, 229 ... Buffer memory (SDRAM), 230 ... Recording medium, 231 ... Microcomputer for body control (B [mu] com), 232 ... Drive circuit 233 ... LED for auxiliary light, 234 ... LCD for operation display, 235 ... Camera operation switch (SW), 236 ... Power supply circuit, 237 ... Battery, 238 ... Photometry circuit, 239 ... Non-volatile memory (EEPROM), 240 ... Communication Connector, 241... Charging circuit, 24 ... light-emitting circuit, 243 ... light-emitting tube, 244 ... reflector, 245 ... charging voltage detection circuit

Claims (7)

In a strobe device that is installed at a position away from the camera and performs settings according to parameters input by wireless communication with the camera,
Ranging means for detecting the distance from the strobe device to the subject;
A calculation means for calculating a light emission amount from the parameter input by the wireless communication and the distance detected by the distance measurement means,
A light emitting means for emitting light in synchronization with the exposure of the camera at the calculated light emission amount;
A strobe device comprising:   2. The strobe device according to claim 1, wherein the light emitting means is synchronized with light emission of a strobe device built in the camera or connected to the camera. The parameters input in the wireless communication include the aperture value and correction coefficient of the camera,
3. The strobe device according to claim 1, wherein the calculating unit calculates a light emission guide number as the light emission amount from the distance, the aperture value, and the correction coefficient.   The strobe device according to claim 3, wherein the correction coefficient includes a light emission ratio of the strobe device. Ranging means for detecting the distance to the subject in the direction of the light emitting unit,
Communication means for communicating with the camera and receiving at least the aperture value of the camera;
A light emitting means for emitting light in synchronization with the main light emission of a strobe device built in the camera or connected to the camera;
An arithmetic means for calculating the light emission amount of the light emitting means from the distance detected by the distance measuring means and the aperture value obtained by the communication;
A strobe device comprising:   6. The strobe device according to claim 5, wherein the light emitting unit and the distance measuring means are configured to be rotatable with respect to a main body of the strobe device. A slave mode that emits light in synchronization with the main flash of a strobe device built in the camera or connected to the camera, and a main mode that emits light in synchronization with the exposure timing of the camera connected to the camera In the strobe device,
Ranging means for detecting the distance to the subject;
Wireless communication means for wirelessly communicating with the camera in the slave mode;
Wired communication means for communicating with the camera by wire in the main mode;
When communicating with the camera wirelessly, light is emitted with the light emission amount obtained from the distance detected by the distance measuring means and the aperture value of the camera, and when communicating with the camera via wire, the camera instructs. A light emitting means for emitting light with a light emission amount,
A strobe device comprising:

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