Electronic equipment and accessories

Abstract

By considering its relationship with other contact points, it enables the creation of functions suitable for accessories attached to the camera. [Solution] An accessory 200 is detachably attached to the electronic device 100. The electronic device has a row of multiple contacts that are electrically connected to the accessory. The multiple contacts include a functional signal contact TC17 to which signals of different functions are connected depending on the type of accessory, a reference potential contact TC18 to which a reference potential is connected, and contacts used for supplying power to the accessory or for communication with the accessory. The functional signal contact and the reference potential contact are arranged adjacent to each other.

Description

Technical Field

[0001] The present invention relates to an electronic device and an accessory having contacts used for communication, power supply, and the like.

Background Art

[0002] An accessory shoe provided on an electronic device such as a camera is equipped with an accessory such as a strobe device. The accessory shoe is provided with a plurality of contacts (terminals) for supplying power to the accessory and communicating with the accessory.

[0003] Patent Document 1 discloses an accessory in which a notification contact for notifying a camera of a state in which an accessory can be activated and a data contact for outputting a data signal to the camera are arranged adjacent to each other, and a GND contact is arranged adjacent to the data contact.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, Patent Document 1 only discloses the arrangement of a plurality of contacts with fixed functions.

[0006] The present invention provides an accessory and an electronic device having functions suitable for being mounted on an electronic device while considering the relationship with other contacts.

Means for Solving the Problems

[0007] One aspect of the present invention is an electronic device to which an accessory can be detachably attached. The electronic device has a plurality of contacts arranged in a row that are electrically connected to the accessory. The plurality of contacts include a functional signal contact to which signals of different functions are connected depending on the type of accessory, a reference potential contact to which a reference potential is connected, and data communication contacts and clock signal communication contacts used for communication with the accessory. The contact to which the highest frequency signal among the plurality of functional signal contacts is connected and the reference potential contact are arranged adjacent to each other, the contact to which the highest frequency signal is connected is arranged adjacent to other contacts included in the plurality of functional signal contacts, there are no contacts connected to the reference potential adjacent to the other contacts, and the contact to which the highest frequency signal is connected is further away from the clock signal communication contact than the other contacts.

[0008] Furthermore, an accessory, as another aspect of the present invention, is detachably attached to an electronic device. The accessory has a plurality of contacts arranged in a row that are electrically connected to the electronic device. The plurality of contacts include a plurality of functional signal contacts to which signals of functions according to the type of accessory are connected, a reference potential contact to which a reference potential is connected, and data communication contacts and clock signal communication contacts used for communication with the electronic device. The contact to which the highest frequency signal among the plurality of functional signal contacts is connected and the reference potential contact are arranged adjacent to each other, the contact to which the highest frequency signal is connected is arranged adjacent to other contacts included in the plurality of functional signal contacts, there are no contacts connected to the reference potential next to the other contacts, and the contact to which the highest frequency signal is connected is further away from the clock signal communication contact than the other contacts. [Effects of the Invention]

[0009] According to the present invention, it is possible to realize a function suitable for an accessory attached to an electronic device, while taking into consideration its relationship with other contacts. [Brief explanation of the drawing]

[0010] [Figure 1]A diagram showing the configuration of the camera and accessories in an embodiment of the present invention. [Figure 2] A diagram showing an example of a camera with accessories attached and the arrangement of their contacts in an embodiment. [Figure 3] A diagram showing how an external force is applied to an accessory attached to the camera in the embodiment. [Figure 4A] A diagram showing the configuration for determining the connection status of the ground contact in the embodiment. [Figure 4B] A flowchart illustrating the process performed by the camera in the embodiment. [Figure 5] A flowchart illustrating the process performed by the camera in the embodiment. [Figure 6] A timing chart showing the signal change when a power supply contact and an adjacent contact in the embodiment are short-circuited. [Figure 7] A diagram showing an example of assigning functional signals to accessory types in an embodiment. [Figure 8] A diagram showing the configuration of the connection destinations for functional signals in the embodiment. [Figure 9] A diagram showing an example configuration of the camera and accessories in the embodiment. [Figure 10] A diagram showing other configuration examples of the camera and accessories in the embodiment. [Figure 11] A diagram showing yet another example of the camera and accessories configuration in the embodiment. [Figure 12] A diagram showing an example of the accessory configuration in the embodiment. [Figure 13] A diagram showing an example configuration of the camera, accessories, and intermediate accessories in the embodiment. [Figure 14] A diagram showing other configuration examples of the camera, accessories, and intermediate accessories in the embodiment. [Figure 15] Timing chart for the case where the accessory is a strobe device in the embodiment. [Figure 16] A perspective view of the camera and an external flash unit, which is an accessory in the embodiment. [Figure 17]Exploded view and perspective view of the accessory shoe in the embodiment. [Figure 18] Diagram showing the structure of the engagement member and the connection terminal connector of the accessory shoe in the embodiment. [Figure 19] Perspective view and cross-sectional view of the external flash unit in the embodiment. [Figure 20] Perspective view and front view showing the internal structure of the camera connection part in the embodiment. [Figure 21] Top view and cross-sectional view of the camera connection part in the embodiment. [Figure 22] Perspective view and cross-sectional view of the external flash unit as a modification. [Figure 23] Perspective view and front view showing the internal structure of the connection part in the modification. [Figure 24] Front view of the accessory shoe in the embodiment. [Figure 25] Enlarged view of a part of the connection plug in the embodiment. [Figure 26] Front cross-sectional view showing the state in which the camera connection part is attached to the accessory shoe in the embodiment.

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] FIG. 1 shows the electrical configuration of a camera 100 as an electronic device according to an embodiment of the present invention and an accessory 200 that is detachably attached thereto. The camera 100 and the accessory 200 are electrically connected by the plurality of contacts (terminals) TC01 to TC21 of the camera connection part 141 provided in the camera 100 and the plurality of contacts TA01 to TA21 of the accessory connection part 211 provided in the accessory 200 coming into one-to-one contact with each other.

[0013] The camera 100 is powered by the battery 111. The battery 111 is detachable from the camera 100. The camera control circuit 101, which serves as a control means for the camera 100, is a circuit that controls the entire camera 100 and is composed of a microcomputer with a built-in CPU, etc.

[0014] The system power supply circuit 112 is a circuit that generates power to supply to each circuit of the camera 100, and consists of a DC-DC converter circuit, an LDO (Low Drop Out), and a charge pump circuit, etc. The voltage of 1.8V generated by the system power supply circuit 112 is constantly supplied from the battery 111 to the camera control circuit 101 as the camera microcontroller power supply VMCU_C. The camera control circuit 101 controls the on / off switching of power supply to each circuit of the camera 100 by controlling the system power supply circuit 112.

[0015] The optical lens 121 is detachable from the camera 100. Light from a subject entering through the optical lens 121 is formed on an image sensor 122, which is made up of a CMOS sensor or a CCD sensor. The subject image formed on the image sensor 122 is encoded into a digital imaging signal. The image processing circuit 123 performs image processing such as noise reduction and white balance processing on the digital imaging signal to generate image data, and converts the image data into an image file such as JPEG format for recording in the recording memory 126. The image processing circuit 123 also generates VRAM image data from the image data for display on the display circuit 127.

[0016] The memory control circuit 124 controls the transmission and reception of image data and other data generated by the image processing circuit 123, etc. The volatile memory 125 is a high-speed read and write memory such as DDR3 SDRAM, and is used as a workspace for image processing performed by the image processing circuit 123. The recording memory 126 is a read / write recording medium such as an SD card or CFexpress card that can be attached to and detached from the camera 100 via a connector (not shown). The display circuit 127 is a display located on the back of the camera 100 and is composed of an LCD panel or an organic EL display panel, etc. The backlight circuit 128 adjusts the brightness of the display circuit 127 by changing the light intensity of the backlight of the display circuit 127.

[0017] The accessory power supply circuits A131 and B132, which serve as power supply means, are voltage conversion circuits that convert the voltage supplied from the system power supply circuit 112 to a predetermined voltage, and in this embodiment, they generate 3.3V as the accessory power supply VACC.

[0018] The accessory power supply circuit A131 is a power supply circuit with low self-power consumption, consisting of an LDO, etc. The accessory power supply circuit B132 is a circuit consisting of a DC / DC converter circuit, etc., and can supply a larger current than the accessory power supply circuit A131. However, the self-power consumption of the accessory power supply circuit B132 is greater than that of the accessory power supply circuit A131. Therefore, when the load current is small, the accessory power supply circuit A131 is more efficient than the accessory power supply circuit B132, and when the load current is large, the accessory power supply circuit B132 is more efficient than the accessory power supply circuit A131. The camera control circuit 101 controls the on / off switching of the voltage output of the accessory power supply circuit A131 and the accessory power supply circuit B132 according to the operating state of the accessory 200.

[0019] The protection circuit 133, acting as a protective measure, is composed of a current fuse element, a polyswitch element, or an electronic fuse circuit combining a resistor, amplifier, and switch element. It outputs an overcurrent detection signal DET_OVC when the power supply current value supplied to the accessory 200 from the accessory power supply circuit A131 and accessory power supply circuit B132 exceeds a predetermined value and becomes excessive (abnormal). In this embodiment, the protection circuit 133 is an electronic fuse circuit, and when a current of 1A or more flows, it notifies the camera control circuit 101 with an overcurrent detection signal DET_OVC. The overcurrent detection signal DET_OVC indicates an overcurrent when it is at a Hi level.

[0020] The camera connection section 141 is a connector for making an electrical connection to the accessory 200 via 21 contacts TC01 to TC21 arranged in a row. The contacts TC01 to TC21 are arranged in this order from one end to the other in the direction of their arrangement.

[0021] TC01 is connected to ground (GND) and serves not only as a reference potential (GND potential) contact, but also as a contact that controls the wiring impedance of the differential signals D1N and D1P, which will be explained next. TC01 corresponds to the third ground contact.

[0022] The differential signal D1N connected to TC02 and the differential signal D1P connected to TC03 are differential data communication signals that work together as a pair for data communication and are connected to the camera control circuit 101. TC02, TC03, and TC07-TC17, TC19, and TC20 (described later) are communication contacts.

[0023] TC04, acting as the first ground contact, is connected to GND and serves as the reference potential contact for camera 100 and accessory 200. TC04 is positioned further outward in the contact arrangement direction than TC05, which will be described next.

[0024] The accessory power supply VAC, generated by accessory power supply circuits A131 and B132, is connected to TC05, which acts as a power supply contact, via protection circuit 133.

[0025] The accessory installation detection signal / ACC_DET is connected to TC06, which serves as the installation detection contact. The accessory installation detection signal / ACC_DET is pulled up to the camera microcontroller power supply VMCU_C via the resistor element Rp134 (10kΩ). The camera control circuit 101 can detect whether accessory 200 is installed or not by reading the signal level of the accessory installation detection signal / ACC_DET. If the signal level (potential) of accessory installation detection signal / ACC_DET is at a Hi level (predetermined potential), accessory 200 is detected as not being installed, and if it is at a Lo level (GND potential as described later), accessory 200 is detected as being installed.

[0026] When the camera 100 is powered on, the signal level (potential) of the accessory installation detection signal / ACC_DET changes from a high level to a low level, which triggers various communications between the camera 100 and the accessory 200 via contacts.

[0027] The camera control circuit 101 detects that the accessory 200 is attached and supplies power to the accessory 200 via the TC05, which acts as a power contact.

[0028] The SCLK connected to TC07, the MOSI connected to TC08, the MISO connected to TC09, and the CS connected to TC10 are signals for the camera control circuit 101 to act as a communication master and perform SPI (Serial Peripheral Interface) communication. In this embodiment, the communication clock frequency for SPI communication is 1 MHz.

[0029] TC11 is connected to a communication request signal / WAKE from accessory 200 to camera control circuit 101 to request communication. The communication request signal / WAKE is pulled up to the camera microcontroller power supply VMCU_C via a resistor. The camera control circuit 101 can receive the communication request from accessory 200 by detecting the falling edge of the communication request signal / WAKE.

[0030] SDA, connected to TC12, and SCL, connected to TC13, are signals for the camera control circuit 101 to act as the communication master and perform I2C (Inter-Integrated Circuit) communication. SDA and SCL are signals for open-drain communication (hereinafter referred to as open-drain communication) pulled up to the camera microcontroller power supply VMCU_C, and in this embodiment, the communication frequency is 100kbps.

[0031] In I2C communication, both data transmission from camera 100 and data transmission from accessory 200 are performed via SDA. Comparing SPI communication and I2C communication, I2C communication is slower and enables communication with lower power consumption. Also, because SPI communication is faster than I2C communication, it is suitable for transmitting large amounts of data. Therefore, in the communication between camera 100 and accessory 200 in this embodiment, large amounts of data are transmitted using SPI communication, and small amounts of data are transmitted using I2C communication. For example, data can be transmitted first using I2C communication, and then, based on this data, if SPI communication is possible or necessary, it can be controlled to execute SPI communication.

[0032] The FNC1 signal connected to TC14 (synchronous contact), the FNC2 signal connected to TC15, the FNC3 signal connected to TC16, and the FNC4 signal connected to TC17 are signals whose function can be changed depending on the type of accessory 200 attached. For example, if accessory 200 is a microphone device, the signal communicated via TC15 will be an audio data signal. If accessory 200 is a lighting (strobe or flash) device, the signal communicated via TC14 will be a signal that controls the timing of the light emission. Depending on the type of accessory attached, signals that realize different functions may be communicated via the same contact. For example, if accessory 200 is an accessory other than a lighting device, a synchronous signal to control a timing different from the light emission timing may be communicated via TC14. TC14 to TC17 correspond to functional signal contacts. Communication using at least one of the functional signal contacts is also called functional signal communication.

[0033] Functional signal communication can be performed in parallel with I2C and SPI communication, and at a timing independent of I2C and SPI communication.

[0034] The types of accessories referred to here include the microphone equipment and lighting equipment mentioned above. Accessories that perform the same function for the same purpose are of the same type, just as lighting fixtures with different performance characteristics are different types of accessories. Accessories that perform different functions for different purposes, such as microphone equipment and lighting equipment, are different types of accessories.

[0035] Functional signal communication is performed based on information obtained via I2C or SPI communication.

[0036] TC18, which serves as a second ground contact (reference potential contact), is also connected to GND and, like TC04, is a contact that provides the reference potential for camera 100 and accessory 200.

[0037] The differential signal D2N connected to TC19 (first differential signal contact) and the differential signal D2P connected to TC20 (second differential signal contact) are data communication signals that work together as a pair to communicate data, and are connected to the camera control circuit 101. For example, USB communication can be performed via TC19 and TC20.

[0038] TC21 is connected to GND and serves not only as a reference potential contact but also as a contact that controls the wiring impedance of differential signals D2N and D2P. TC21 corresponds to the fourth ground contact. Contacts TC01, TC04, TC06, TC18, and TC21 are connected to the GND portion of the flexible circuit board 158, as shown in Figure 17 later, and the GND portion of the flexible circuit board 158 is fixed to a metallic component that is at the GND level of the camera 100 with screws 157 or the like. The metallic component that is at the GND level is, for example, the engaging member 151 or a base plate inside the camera 100 (not shown).

[0039] In this embodiment, an accessory installation detection contact TC06, to which the accessory installation detection signal / ACC_DET is connected, is placed next to the contact TC07 (first clock contact) that transmits the clock signal SCLK (first clock signal). Generally, noise (clock noise) associated with potential fluctuations of the clock signal is transmitted to contacts adjacent to the clock signal contact, and this can cause malfunctions. In particular, in a configuration with a large number of contacts and short distances between contacts, as in this embodiment, the effect becomes even greater. Therefore, by placing the installation detection contact TC06 next to the SCLK contact TC07, the effect of clock noise can be suppressed.

[0040] The accessory installation detection signal / ACC_DET is pulled up before the accessory is installed, but is set to GND potential after the accessory is installed. On the other hand, the SCLK contact TC07, which transmits the clock signal, does not transmit the clock signal before the accessory is installed, so there is no potential fluctuation, and the potential fluctuates only after the accessory is installed because it transmits the clock signal.

[0041] When the SCLK contact TC07 transmits the clock signal, the attachment detection contact TC06 is at GND potential. Therefore, even if the attachment detection contact TC06 is affected by clock noise, the potential of the control circuits of the camera 100 and accessory 200 is less likely to fluctuate, thus preventing malfunctions. In addition, it is possible to suppress the transmission of clock noise to locations further away from the attachment detection contact TC06. As a result, it is not necessary to provide a GND terminal, and the effects of clock noise can be suppressed without increasing the number of contacts.

[0042] Furthermore, the SCL (second clock signal) is also transmitted as a clock signal to the contact (second clock contact) TC13. However, the SCLK transmitted to the SCLK contact TC07 has a higher frequency than SCL, and therefore generates more clock noise from the SCLK contact TC07 than from the SCL contact TC13. For this reason, placing the mounting detection contact TC06 next to the SCLK contact TC07 rather than next to the SCL contact TC13 is more effective in preventing malfunctions caused by clock noise.

[0043] Furthermore, in addition to the difference in frequency, the SCL transmitted by the SCL contact TC13 is the clock signal of the I2C communication standard, and the voltage fluctuations of the signal line are driven by an open-drain connection. On the other hand, the SCLK transmitted by the SCLK contact TC07 is the clock signal of the SPI communication standard, and the voltage fluctuations of the signal line are driven by a CMOS output. For this reason, the voltage fluctuation edges of the SCL contact TC13 tend to be smoother than those of the SCLK contact TC07, and clock noise is less likely to occur. Therefore, placing the attachment detection contact TC06 next to the SCLK contact TC07 rather than next to the SCL contact TC13 is more effective in preventing malfunctions due to clock noise.

[0044] Furthermore, the first and second differential signal contacts TC19 and TC20 may also transmit differential signals D1N and D1P in pairs to transmit a clock signal. In this case, a clock signal with a higher frequency than that transmitted by the SCLK contact TC07 and SCL contact TC13 (a third clock signal) may be transmitted. However, because the differential signals D1N and D1P are paired signals, they emit less clock noise than the SCLK contact TC07 and SCL contact TC13, which transmit single-ended signals. For this reason, placing the mounting detection contact TC06 next to the SCLK contact TC07 rather than next to the first and second differential signal contacts TC19 and TC20 is more effective in preventing malfunctions due to clock noise.

[0045] Furthermore, the contact TC08 (the first data contact), located adjacent to the mounting detection contact TC06 on the opposite side of the SCLK contact TC07, transmits MOSI (the first data signal). Since MOSI is a data signal, it might seem susceptible to clock noise. However, because MOSI is a data signal using the same SPI communication standard as the clock signal transmitted by the SCLK contact TC07, the timing of its potential fluctuations is synchronized with the clock signal, making it less susceptible to clock noise. For this reason, contact TC08 does not need to be fixed to GND potential and can be used as a MOSI contact.

[0046] Accessory 200 has a battery 205 and receives power from the battery 205, as well as power from the camera 100 via the camera connection part 141 and accessory connection part 211. The accessory control circuit 201, which serves as a control means for accessory 200, is a circuit that controls the entire accessory 200 and is a microcomputer with a built-in CPU, etc.

[0047] The accessory power supply circuit 202 is a circuit that generates power to supply each circuit of the accessory 200, and is composed of a DC-DC converter circuit, an LDO, a charge pump circuit, etc. The accessory control circuit 201 is constantly supplied with 1.8V, a voltage generated by the accessory power supply circuit 202, as the accessory microcontroller power supply VMCU_A. By controlling the accessory power supply circuit 202, the on / off control of the power supply to each circuit of the accessory 200 is performed.

[0048] The charging circuit 204 is a circuit for charging the battery 205 using power supplied from the camera 100. When the accessory control circuit 201 determines that sufficient power is being supplied from the camera 100 to perform the charging operation, it controls the charging circuit 204 to charge the battery 205. In this embodiment, the case in which the battery 205 is attached to the accessory 200 is described, but the accessory 200 may operate using only power supplied from the camera 100 without the battery 205 being attached. In this case, the charging circuit 204 is not necessary.

[0049] The differential communication circuit 207 is a circuit for performing differential communication with the camera 100 and can transmit and receive data between it and the camera 100. The external communication IF circuit 208 is an IF circuit for performing data communication with external devices (not shown), and is an Ethernet communication IF, a wireless LAN communication IF, a public network communication IF, etc.

[0050] The accessory control circuit 201 controls the differential communication circuit 207 and the external communication IF circuit 208, enabling it to transmit data received from the camera 100 to an external device and transmit data received from an external device to the camera 100. The function circuit 206 is a circuit that has different functions depending on the type of accessory 200. An example of the configuration of the function circuit 206 will be described later.

[0051] The external connection terminal 209 is a connector terminal for connecting to an external device, and in this embodiment, it is a USB TYPE-C connector. The connection detection circuit 210 is a circuit for detecting when an external device is connected to the external connection terminal 209, and the accessory control circuit 201 can detect the connection of an external device to the external connection terminal 209 by receiving the output signal of the connection detection circuit 210.

[0052] The power switch 203 is a switch for turning the accessory 200 on and off, and the accessory control circuit 201 can detect the on and off positions by reading the signal level of the terminal to which the power switch 203 is connected.

[0053] The accessory connection section 211 is a connector for making an electrical connection to the camera 100 via 21 contacts TA01 to TA21 arranged in a row. The contacts TA01 to TA21 are arranged in this order from one end to the other in the direction of their arrangement.

[0054] TA01 is connected to GND and serves not only as a reference potential contact but also as a contact that controls the wiring impedance of differential signals D1N and D1P. TA01 corresponds to a third ground contact.

[0055] The differential signal D1N connected to TA02 and the differential signal D1P connected to TA03 are data communication signals that work together as a pair to perform data communication, and are connected to the differential communication circuit 207. TA02, TA03, and TA07-TA17, TA19, and TA20 (described later) are communication contacts.

[0056] TA04, acting as the first ground contact, is connected to GND and serves as the reference potential contact for camera 100 and accessory 200. TA04 is positioned further outward in the contact arrangement direction than TA05, which will be described next.

[0057] The TA05, which serves as a power contact, is connected to the accessory power circuit 202 and the charging circuit 204, and the accessory power supply VAC supplied from the camera 100 is connected to it.

[0058] TA06, acting as an attachment detection contact, is directly connected to GND. When accessory 200 is attached to camera 100, the aforementioned accessory attachment detection signal / ACC_DET is set to a GND level (Lo level). This provides a contact for camera 100 to detect the attachment of accessory 200.

[0059] The SCLK connected to TA07, the MOSI connected to TA08, the MISO connected to TA09, and the CS connected to TA10 are signals that enable the accessory control circuit 201 to act as a communication slave and perform SPI communication.

[0060] TA11 is connected to a communication request signal / WAKE from the accessory control circuit 201 to request communication from the camera 100. When the accessory control circuit 201 determines that communication with the camera 100 is necessary, it sends a communication request to the camera 100 by outputting the communication request signal / WAKE as a Lo signal.

[0061] When the camera control circuit 101 detects that the accessory 200 is attached and supplies power to the accessory 200 via TC5, the accessory control circuit 201 notifies the camera control circuit 101 that power has been supplied by changing the signal level (potential) of the communication request signal / WAKE from a Hi level to a Lo level.

[0062] The accessory control circuit 201 can notify the camera 100 that an event has occurred that requires the accessory 200 to communicate with the camera 100, by changing the signal level (potential) of the communication request signal / WAKE from a Hi level to a Lo level, even without a request from the camera. With this configuration, the camera control circuit 101 can omit the operation of periodically checking whether an event requiring communication has occurred by polling the accessory 200. In addition, the accessory 200 can communicate this to the camera 100 in real time when an event requiring communication occurs.

[0063] The SDA connected to TA12 and the SCL connected to TA13 are signals that enable the accessory control circuit 201 to act as a communication slave and perform I2C communication.

[0064] The FNC1 signal connected to TA14 (synchronous contact), the FNC2 signal connected to TA15, the FNC3 signal connected to TA16, and the FNC4 signal connected to TA17 are signals whose function can be changed depending on the type of accessory 200. For example, if accessory 200 is a microphone device, it will be an audio data signal, and if accessory 200 is a strobe device, it will be a signal that controls the timing of the flash. TA14 to TA17 correspond to function signal contacts.

[0065] TA18, which acts as a second ground contact (reference potential contact), is also connected to GND, and like TA04, it serves as the reference potential contact for camera 100 and accessory 200.

[0066] The differential signal D2N connected to TA19 (first differential signal contact) and the differential signal D2P connected to TA20 (second differential signal contact) are data communication signals that work together as a pair to perform data communication, and are connected to the external connection terminal 209.

[0067] TA21 is connected to GND and serves not only as a reference potential contact but also as a terminal that controls the wiring impedance of differential signals D2N and D2P. TA21 corresponds to the fourth ground contact.

[0068] Contacts TA01, TA04, TA06, TA18, and TA21 are connected, for example, to the GND portion of the flexible circuit board 259 shown in Figure 19, which will be described later. The GND portion of the flexible circuit board 259 is fixed to a metallic component that is at the GND level of the accessory 200 with screws (not shown). Examples of metallic components that are at the GND level include the shoe mounting legs 251 and a base plate (not shown) inside the accessory 200.

[0069] Figure 2(a) shows the state in which the accessory connector 211, located on the shoe located on the bottom of the accessory (strobe device) 200, is connected to the camera connector 141, located on the accessory shoe located on the top of the camera 100. Figure 2(b) shows an example of the arrangement of the 21 contacts TC01 to TC21 on the camera connector 141. TC01 is located at the far right when viewed from the subject side, and the 21 contacts up to TC21 are arranged in a single row. The accessory shoe is attached to the accessory shoe having this camera connector 141 by sliding it from the top to the bottom as shown in Figure 2(b).

[0070] Figure 2(c) shows an example of the arrangement of the 21 contacts TA01 to TA21 in the accessory connection section 211. Similar to the camera connection section 141, TA01 is located at the right end when viewed from the subject side, and the 21 contacts up to TA21 are arranged in a single line. Normally, contacts TA01 to TA21 and their corresponding contacts TC01 to TC21 are in contact with each other. However, if excessive static pressure or impact is applied to the accessory 200, the contacts may separate. In particular, if a rotational force is applied to the accessory 200 in the direction in which the contacts are aligned, contact separation is likely to occur at the end contacts.

[0071] Figure 3(a) exaggerates the effect of excessive static pressure being applied to accessory 200 from the left side as viewed from the subject. In this case, a force acts on contacts TC21, TA21 and nearby contacts of the camera connection part 141 and accessory connection part 211 in a direction that causes them to separate, making poor contact more likely. On the other hand, a force acts on contacts TC01, TA01 and nearby contacts that is more in the direction of contact than in the normal state.

[0072] Figure 3(b) exaggerates the effect of excessive static pressure being applied to accessory 200 from the right side as viewed from the subject. In this case, a force acts on contacts TC01, TA01 and nearby contacts of the camera connection part 141 and accessory connection part 211 in a direction that causes them to separate, making poor contact more likely. On the other hand, a force acts on contacts TC21, TA21 and nearby contacts that is more in the direction of contact than in the normal state.

[0073] In this embodiment, the contacts TC01, TA01 and TC21, TA21 at both ends of the camera connection section 141 and the accessory connection section 211 are connected to GND. This ensures that even if a temporary contact failure occurs at one end due to excessive static pressure, a GND connection can be maintained at the other end. Therefore, the risk of the reference potential of the accessory 200 becoming unstable due to a poor GND connection, and consequently damaging various circuits and electrical components, can be reduced.

[0074] Furthermore, if an accessory 200 is installed that lacks some GND contacts due to a defect in the accessory connection section 211, the camera control circuit 101 cannot detect that some of the GND contacts are missing. In such cases, the operating current will concentrate on the remaining GND contacts, which may cause malfunction of the accessory 200.

[0075] Figure 4A shows an example of a configuration that allows the camera 100 to detect the connection status of the GND contact of the accessory 200, and is an excerpt of the configuration shown in Figure 1 that relates to the ground contact.

[0076] TC01, TC04, TC18, and TC21 are connected to input terminals P1, P2, P3, and P4 of the camera control circuit 101, respectively, and are pulled up to the camera microcontroller power supply VMCU_C via resistors 1011Rp_g1, 1021Rp_g2, 1031Rp_g3, and 1041Rp_g4. SW circuits 1 (1012), 2 (1022), 3 (1032), and 4 (1042) are also connected to TC01, TC04, TC18, and TC21, respectively.

[0077] SW circuit 1 is a switch circuit driven by the control signal of the camera control circuit 101, and when turned on by the control signal, TC01 is connected to GND. SW circuit 1 is preferably made up of a FET, for example, and is a circuit in which the impedance when the operation is on is as small as possible and the impedance when the operation is off is as large as possible. SW circuits 2, 3, and 4 have the same configuration as SW circuit 1, as shown in Figure 4A.

[0078] The flowchart in Figure 4B shows the sequence for determining the connection state of the ground terminal in the configuration shown in Figure 4A. The camera control circuit 101 executes this process and other processes described later according to the computer program. S stands for step.

[0079] In S1001, the camera control circuit 101 monitors the signal level of the accessory installation detection signal / ACC_DET and determines whether or not accessory 200 is installed. If the signal level is Hi, the camera control circuit 101 assumes that accessory 200 is not installed and returns to S1001 to perform the detection again. If the signal level is Lo, it assumes that accessory 200 is installed and proceeds to S1002.

[0080] In S1002, the camera control circuit 101 controls the following: turning on SW circuit 1, and turning off SW circuits 2, 3, and 4, respectively.

[0081] In S1003, the camera control circuit 101 checks the voltage level of the input terminal P1. If the level is low, it determines that TC01 is connected to the ground contact; if the level is high, it determines that TC01 is not connected to the ground contact.

[0082] Next, in S1004, the camera control circuit 101 controls the following: turning on SW circuit 2, and turning off SW circuits 1, 3, and 4 respectively.

[0083] In S1005, the camera control circuit 101 checks the voltage level of the input terminal P2. If the level is low, it determines that TC04 is connected to the ground contact; if the level is high, it determines that TC04 is not connected to the ground contact.

[0084] Next, in S1006, the camera control circuit 101 controls the following: turning on SW circuit 3, and turning off SW circuits 1, 2, and 4 respectively.

[0085] In S1007, the camera control circuit 101 checks the voltage level of input terminal P3. If the level is low, it determines that TC18 is connected to the ground contact; if the level is high, it determines that it is not connected to the ground contact.

[0086] Next, in S1008, the camera control circuit 101 controls the following: turning on SW circuit 4, and turning off SW circuits 1, 2, and 3 respectively.

[0087] In S1009, the camera control circuit 101 checks the voltage level of the input terminal P4. If the level is low, it determines that TC18 is connected to the ground contact; if the level is high, it determines that TC18 is not connected to the ground contact.

[0088] In S1010, the camera control circuit 101 controls the switching on of SW circuits 1, 2, 3, and 4, respectively.

[0089] By performing this type of control, it becomes possible to check the connection status of the ground contact between the camera control circuit 101 and the accessory 200 to which it is attached, and to determine whether or not to supply power to the accessory power circuit 202 based on the ground connection status.

[0090] By the way, if the accessory 200 is tilted relative to the camera 100 when it is attached to the camera 100, it is possible that only some of the multiple contacts TC01~TC21 and TA01~TA21 will make contact. As shown in Figure 16, when the direction in which the accessory 200 is attached to the camera 100 is the Z direction, the direction in which the multiple contacts TC01~TC21 and TA01~TA21 are aligned is the X direction, and the direction perpendicular to the X and Z directions is the Y direction, the situation in which only some of the contacts make contact may occur in the following cases.

[0091] First, as shown in Figures 3(a) and (b), when the accessory 200 is tilted around an axis parallel to the Z direction relative to the camera 100, the contacts on the side where the camera 100 and accessory 200 are close together will make contact, but the contacts on the side where the camera 100 and accessory 200 are far apart will not make contact. Also, although not shown in the figures, when the accessory 200 is tilted (twisted) around an axis parallel to the Y direction relative to the camera 100, the contacts on the opposite side of the contacts will separate.

[0092] As will be explained in detail later using Figure 5, in this embodiment, when the accessory 200 is attached to the camera 100, an attachment detection process is performed prior to various communications. At this time, the attachment detection process can be executed if the attachment detection contacts TC06 and TA06 are in contact. After the attachment detection process via contacts TC06 and TA06 is performed, a communication request signal / WAKE is output from the accessory 200 to the camera 100 via contacts (hereinafter also called communication request contacts) TC11 and TA11. The camera 100 detects this communication request signal / WAKE and determines that the accessory 200 is in a state where it can communicate, and then performs various communications. However, if the camera 100 detects that the accessory 200 is attached to the camera 100 but does not detect the communication request signal / WAKE, the camera 100 determines that a communication error has occurred with the accessory 200. If accessory 200 is tilted or twisted during the attachment process to camera 100, it may temporarily cause only some of the multiple contacts to make contact, leading to a communication error being detected and error handling such as a warning being triggered. This could cause the user to mistakenly believe that accessory 200 is malfunctioning.

[0093] Therefore, in this embodiment, a contact arrangement is adopted that reduces the occurrence of a situation in which the camera 100 cannot detect the communication request signal / WAKE even though the attachment of the accessory 200 to the camera 100 has been detected.

[0094] As mentioned above, when the accessory 200 is tilted around an axis parallel to the Z direction relative to the camera 100, either contacts TC01, TA01 and their vicinity make contact while contacts TC21, TA21 and their vicinity do not, as shown in Figure 3(a), or contacts TC21, TA21 and their vicinity make contact while contacts TC01, TA01 and their vicinity do not, as shown in Figure 3(b).

[0095] In this embodiment, contacts TC06 and TA06 are used to detect the attachment of accessory 200 to camera 100. As shown in Figure 3(a), when contacts TC01 and TA01 are in contact, contacts TC06 and TA06 located nearby are often also in contact. In this case, if communication request contacts TC11 and TA11 are located near the distant contacts TC21 and TA21, camera 100 is likely to be unable to detect the communication request signal / WAKE even though the attachment of accessory 200 to camera 100 has been detected.

[0096] On the other hand, as shown in Figure 3(b), when contacts TC06 and TA06 are in contact with contacts TC21 and TA21, if contacts TC11 and TA11 are located on the side of contacts TC01 and TA01, which are further away from contacts TC06 and TA06, the camera 100 is likely to be unable to detect the communication request signal / WAKE even though the attachment of accessory 200 to camera 100 has been detected.

[0097] In contrast to these, this embodiment employs the following contact arrangement. As shown in Figure 1, the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11 are placed between the contacts at one end TC01, TA01 and the contacts at the other end TC21, TA21 in the direction in which the multiple contacts TC01~TC21, TA01~TA21 are arranged (hereinafter referred to as the contact arrangement direction). This arrangement is referred to as the first arrangement. Furthermore, the mounting detection contacts TC06, TA06 are placed between the communication request contacts TC11, TA11 and the contacts TC01, TA01. This arrangement is referred to as the second arrangement. In the contact arrangement direction, the distance between the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11 is shorter than the distance between the communication request contacts TC11, TA11 and the contacts TC21, TA21. This arrangement is referred to as the third arrangement. In this embodiment, since contacts TC01 to TC21 and TA01 to TA21 are arranged at equal pitches, the distance between contacts referred to here may be rephrased as the number of other contacts arranged between those contacts, and a short (long) distance can be rephrased as having a small (large) number of other contacts.

[0098] Furthermore, in this embodiment, in the direction of the contact arrangement, the distance between communication request contacts TC11, TA11 and contacts TC01, TA01 is set to be less than or equal to the distance between communication request contacts TC11, TA11 and contacts TC21, TA21. This arrangement is referred to as the fourth arrangement. In particular, in this embodiment, communication request contacts TC11, TA11 are positioned in the center of contacts TC01~TC21, TC01~TC21, and the distance between communication request contacts TC11, TA11 and contacts TC01, TA01 is made equal to the distance between communication request contacts TC11, TA11 and contacts TC21, TA21. Note that communication request contacts TC11, TA11 do not necessarily have to be positioned in the center of contacts TC01~TC21, TC01~TC21, but it is preferable to position them near the center.

[0099] In addition, in this embodiment, in the direction of the contact arrangement, the distance between the mounting detection contacts TC06, TA06 and the contacts TC01, TA01 is set to be greater than or equal to the distance between the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11. This arrangement is referred to as the fifth arrangement. In particular, in this embodiment, the mounting detection contacts TC06, TA06 are positioned in the center between the communication request contacts TC11, TA11 and the contacts TC01, TA01, making the distance between the mounting detection contacts TC06, TA06 and the contacts TC01, TA01 equal to the distance between the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11. Note that the mounting detection contacts TC06, TA06 do not necessarily have to be positioned in the center between the communication request contacts TC11, TA11 and the contacts TC01, TA01, but it is preferable to position them near the center.

[0100] With the contact arrangement described above, if the mounting detection contacts TC06 and TA06 make contact in the tilted state shown in Figure 3(a), there is a high probability that the communication request contacts TC11 and TA11 will also make contact. Conversely, in the tilted state shown in Figure 3(b), even if the communication request contacts TC11 and TA11 make contact, there is a high probability that the mounting detection contacts TC06 and TA06 will not make contact. As a result, regardless of which tilted state the camera 100 is in, the occurrence of a situation in which the camera 100 fails to detect the communication request signal / WAKE despite the camera 100 detecting the mounting of the accessory 200 can be reduced.

[0101] Here, as a comparative example, we will explain the case where the positions of contacts TC06, TA06 and contacts TC11, TA11 are swapped. That is, we will explain the case where contacts TC11, TA11 are used for mounting detection and contacts TC06, TA06 are used for detecting communication request signals / WAKE. In this configuration, if the accessory 200 is tilted relative to the camera 100 and contacts TC01, TA01 and their vicinity do not make contact, contacts TC11, TA11 for mounting detection will make contact, but contacts TC06, TA06 for communication request signals / WAKE will not make contact, which may result in a communication error.

[0102] Therefore, in order to avoid communication errors, it is preferable to place the contact for mounting detection on one end of the contact array direction, rather than the contact for the communication request signal / WAKE, as in this embodiment.

[0103] Furthermore, as shown in Figures 20(a) to (c) and Figure 23 described later, in a configuration where the accessory 200 holds multiple contacts with a connecting plug 256, which is a retaining member made of a non-conductive material such as resin, the connecting plug 256 may have a convex shape toward the downward side in the figure (the direction of contact with the camera connection part 141). In such a case, it is more likely that the contacts on one end in the contact arrangement direction will make contact, but the contacts on the other end will not. However, by adopting a contact arrangement as in this embodiment, even if some contacts become non-contact when the accessory 200 is attached to the camera 100, the occurrence of communication errors can be reduced.

[0104] Furthermore, as mentioned above, if the accessory 200 is twisted around an axis parallel to the Y direction relative to the camera 100, the contacts on one end in the contact arrangement direction may make contact, while the contacts on the other end may not. If this condition occurs during the process of attaching the accessory 200 to the camera 100, a timing difference will occur in the contacts of the multiple contacts. If the timing difference is large, the time lag from the detection of attachment of the accessory 200 to the detection of WAKE will increase, which may result in a communication error. In this case, depending on the direction of twisting of the accessory 200, either contacts TC01 and TA01 will start to make contact first, or contacts TC21 and TA21 will start to make contact first.

[0105] When contact is initiated from the TC01, TA01 side, the closer the communication request contacts TC11, TA11 are to contacts TC21, TA21, the longer the time lag between the detection of accessory 200 being installed and the detection of the communication request signal / WAKE. A longer time lag makes it easier for a communication error to be detected. On the other hand, when contact is initiated from the TC21, TA21 side, if the communication request contacts TC11, TA11 are positioned closer to contacts TC01, TA01 than to the installation detection contacts TC06, TA06, a time lag will occur between the detection of accessory 200 being installed and the detection of the communication request signal / WAKE.

[0106] In contrast to these, this embodiment employs the aforementioned contact arrangement, which shortens the time lag from the detection of accessory 200 attachment to the detection of the communication request signal / WAKE, regardless of which end contact initiates contact.

[0107] Furthermore, in this embodiment, contacts TC07, TA07~TC10, TA10, used for SPI communication (communication using the second communication method) between the camera 100 and the accessory 200, are positioned between the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11. In addition, contacts TC12, TA12, TC13, TA13, used for I2C communication (communication using the first communication method) between the camera 100 and the accessory 200, are positioned close to the communication request contacts TC11, TA11 on the opposite side from the mounting detection contacts TC06, TA06.

[0108] Communication between camera 100 and accessory 200 is performed after camera 100 detects a communication request signal / WAKE. Therefore, contact of the contacts used for communication is not confirmed until communication is performed between camera 100 and accessory 200. In contrast, in this embodiment, if the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11 are in contact, then the communication contacts TC07, TA07~TC10, TA10, TC12, TA12, TC13, TA13 located between and near them can also be considered to be in contact.

[0109] Furthermore, since contact can be considered more reliable at the positions between the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11, it is preferable to place the contacts used for SPI communication, which is executed after I2C communication, at the positions between the mounting detection contacts TC06, TA06 and the communication request contacts TC11, TA11.

[0110] Furthermore, as shown in Figure 4 and Figures 12 and 20 which will be explained later, the accessory 200 may have fewer contacts than the camera 100. Even in such a configuration, the attachment detection contact and the communication request contact are necessary contacts, and it is preferable to arrange the attachment detection contact and the communication request contact in the same manner as in the configuration with the same number of contacts as the camera 100. However, it is not necessary to satisfy some of the arrangement relationships described in the first to fifth points above.

[0111] For example, in a configuration without contact TA21 as shown in Figure 4, the distance between communication request contact TA11 and contact TA01 in the contact arrangement direction is longer than the distance between communication request contact TA11 and contact TA20. In other words, the fourth arrangement relationship described above is not satisfied. Also, for example, in a configuration without contacts TA01~TA03 and TA19~21 as shown in Figure 12, the distance between mounting detection contact TA06 and contact TA04 in the contact arrangement direction is shorter than the distance between mounting detection contact TA06 and communication request contact TA11. In other words, the fifth arrangement relationship described above is not satisfied.

[0112] As described above, in configurations where the position of the contact at the end of the accessory 200 differs from the position of the contact at the end of the camera 100, some of the arrangement relationships described in 1 to 5 above may not be satisfied. In such cases, the attachment detection contact and the communication request contact can be arranged so as to satisfy the arrangement relationships described in 1 to 5 above, by assuming that the position facing the contact at the end of the camera 100 when attached is the position of the contact at the end of the accessory 200. Alternatively, as shown by the projection 256a in Figure 20, the attachment detection contact and the communication request contact can be arranged so as to satisfy the arrangement relationships described in 1 to 5 above, by considering the distance from the projection 256a instead of the distance from the end contact. The flowchart in Figure 5(a) shows the process executed by the camera control circuit 101 when the accessory 200 is attached to the camera 100.

[0113] In S401, the camera control circuit 101, acting as an attachment detection means, monitors the signal level of the accessory attachment detection signal / ACC_DET and determines whether or not the accessory 200 is attached. If the signal level is Hi, the camera control circuit 101 assumes that the accessory 200 is not attached and returns to S401 to perform the detection again. If the signal level is Lo, it assumes that the accessory 200 is attached and proceeds to S402.

[0114] In S402, the camera control circuit 101 sets the power control signal CNT_VACC1 to a high level to turn on the output of the accessory power supply circuit A131 and proceeds to S403. The accessory power supply circuit A131 outputs the accessory power supply VAC in response to the power control signal CNT_VACC1 being high.

[0115] In S403, the camera control circuit 101 monitors the signal level of the overcurrent detection signal DET_OVC and determines whether or not an overcurrent is flowing. If the signal level is low, the camera control circuit 101 assumes that no overcurrent is flowing and proceeds to S404; if the signal level is high, it assumes that an overcurrent is flowing and proceeds to S405 to perform error processing.

[0116] Figure 6(a) schematically shows the changes in the above signals when the process in Figure 5(a) proceeds to S404. IACC is the current of the accessory power supply VACC. In S402, the power control signal CNT_VACC1 is set to Hi and the accessory power supply VACC has started up normally, so the overcurrent detection signal DET_OVC remains at the Lo level.

[0117] Figure 6(b) schematically shows the changes in the above signals when the process in Figure 5(a) proceeds to S405. In S402, after the power control signal CNT_VACC1 is set to Hi, an overcurrent flows through IACC, causing the overcurrent detection signal DET_OVC to change to a Hi level and notify the camera control circuit 101. Upon receiving notification of the overcurrent detection signal DET_OVC, the camera control circuit 101 turns off the outputs of the accessory power supply circuits A131 and B132 as an error handling measure, stopping the power supply to the accessory 200. In this way, even if an overcurrent flows through the accessory power supply VACC, the camera control circuit 101 can detect the overcurrent and safely shut down the system.

[0118] Normally, if an abnormal current flows through the accessory power supply VACC, it would be assumed that the camera 100 and accessory 200 have malfunctioned. However, since the camera connection part 141 and the accessory connection part 211 are exposed to the outside, there is a possibility that foreign objects such as metal fragments may adhere to them and cause a short circuit between adjacent contacts.

[0119] In this embodiment, the accessory power supply VACC has a voltage of 3.3V, while the camera microcontroller power supply VMCU_C and the accessory microcontroller power supply VMCU_A have a voltage of 1.8V. Therefore, if a voltage of 3.3V is applied to an electrical element operating at 1.8V, there is a concern that the electrical element may be damaged. Furthermore, since the behavior after a short circuit depends on the characteristics of the electrical element, the camera control circuit 101 may not always be able to detect a short circuit between terminals. For example, since the I2C communication signal is at a high level in the communication standby state, even if it is short-circuited with a voltage of 3.3V, which is higher than the signal voltage of 1.8V, the abnormality may not be detected depending on the characteristics of the connected electrical element.

[0120] In contrast, in this embodiment, GND contacts TC04 and TA04 are placed on one of the two adjacent contacts TC05 and TA05 of the accessory power supply VACC, while contacts TC06 and TA06 of the accessory installation detection signal / ACC_DET are placed on the other. As explained earlier, the accessory installation detection signal / ACC_DET is connected to GND within the accessory 200. Therefore, even if a short circuit occurs between the contacts, 3.3V will not be applied to the element operating at 1.8V, and the system can be safely shut down by detecting the overcurrent.

[0121] Furthermore, as mentioned earlier, supplying accessory power supply VAC without connecting the GND contact can cause the reference potential of accessory 200 to become unstable, potentially damaging various circuits and electrical components. During equipment operation, external forces may be applied that cause unstable contact at the connector terminals. In contrast, by placing the accessory power supply VAC contact and the GND contact adjacent to each other, as in this embodiment, it becomes less likely that only the accessory power supply VAC contact will be connected compared to placing the accessory power supply VAC contact and the GND contact at distant terminals.

[0122] In this embodiment, the accessory installation detection signal / ACC_DET is connected to GND within the accessory 200, but it may also be configured to be connected to GND via a resistor Rd231, as shown in the accessory 200 in Figure 9. Connecting to GND via resistor Rd231 can reduce the short-circuit current.

[0123] In this case, it is necessary to select a resistor Rd231 with a resistance value such that the voltage obtained by dividing the 1.8V voltage of the camera microcontroller power supply VMCU_C by resistors Rp134 and Rd231 (Rd / (Rp+Rd)) × 1.8V satisfies the Low Level Threshold (Vil) of the camera control circuit 101. For example, if the Low Level Detection Threshold (Vil) of the camera control circuit 101 is 0.33 times the power supply voltage, the resistance value of resistor Rd231 must be 1 / 2 or less of that of resistor Rp134 (10kΩ). In the example in Figure 9, the resistance value of resistor Rd231 is set to 5kΩ.

[0124] Figure 5(b) shows the process executed by the camera control circuit 101 when the accessory 200 having the configuration shown in Figure 9 is attached to the camera 100. Steps S411 to S413 are the same as steps S401 to S403 shown in Figure 5(a), so their explanation is omitted.

[0125] In S414, following S413, the camera control circuit 101 monitors the signal level of the accessory installation detection signal / ACC_DET and determines whether the contacts TC06 and TA06 of the accessory installation detection signal / ACC_DET are shorted to the contacts TC05 and TA05 of the accessory power supply VACC. If the signal level is low, the camera control circuit 101 proceeds to S415, assuming there is no short; if the signal level is high, it proceeds to S416, assuming there is a short, and performs error processing.

[0126] Figure 6(c) schematically shows the state of the above signals when the accessory power supply VACC and the accessory installation detection signal / ACC_DET are short-circuited in accessory 200 having the configuration of Figure 9 with the addition of the resistor element Rd231 (5kΩ). After the power control signal CNT_VACC1 is set to Hi in S402, no overcurrent flows to IACC because the current is limited by the resistor element Rd231.

[0127] On the other hand, the accessory power supply voltage VACC is applied to the accessory installation detection signal / ACC_DET. When the camera control circuit 101 causes the signal level of the accessory installation detection signal / ACC_DET to go high due to interrupt processing or the like, it sets the power control signal CNT_VACC1 to low as an error handling measure, stopping the output of the accessory power supply VACC (power supply to accessory 200). This allows the system to be safely shut down without continuously applying 3.3V to the terminals of the element operating at 1.8V.

[0128] Furthermore, as shown in Figure 10, the accessory 200 may be configured such that the accessory attachment detection signal / ACC_DET is controlled by the accessory control circuit 201 via the NPN transistor 212 acting as a switch to a low level (GND potential). In the configuration shown in Figure 1, the camera control circuit 101 can always detect the accessory 200 when it is attached to the camera 100, but in the configuration shown in Figure 10, the accessory control circuit 201 can notify the camera 100 of the attachment of the accessory 200 at any time.

[0129] Furthermore, as shown in Figure 11, the accessory 200 may be configured by connecting a resistor Rd231 in series with the NPN transistor 212. In this case, similar to the configuration in Figure 1, the resistance value must be less than or equal to half the resistance value of the resistor Rp134 (10kΩ).

[0130] As explained above, according to this embodiment, even if the power contact and the adjacent contact are short-circuited, the safety of the system consisting of the camera 100 and the accessory 200 can be maintained and damage to them can be minimized.

[0131] Figure 7 shows examples of the functions of the FNC1 to FNC4 signals, which are function signals connected to contacts TC14 to TC17 and contacts TA14 to TA17, for each type of accessory 200 (in this case, microphone equipment and strobe equipment).

[0132] In microphone devices, the FNC2 to FNC4 signals are used as a digital audio (I2S: Inter-IC Sound standard) data bus to transfer audio data. Figure 8(a) shows an example configuration of the functional circuit 206 when the accessory 200 is a microphone device.

[0133] The audio processing circuit 206A1 within the functional circuit 206 is a codec circuit that converts the audio signal input from the microphone 206A2 into digital audio (I2S) data format, and is controlled by the accessory control circuit 201. The accessory control circuit 201 can set the sampling frequency and resolution by controlling the audio processing circuit 206A1. In this embodiment, the sampling frequency is 48kHz and the resolution is 32bit. The microphone 206A2 is, for example, a MEMS-IC microphone or an electret condenser microphone.

[0134] TA14 is not used as an I2S data bus for the FNC1 signal and is connected to GND. In this embodiment, unused functional signals are connected to GND, but this is not the only option. It may also be connected to a reference potential that is a stable potential other than GND potential (0V), such as the power supply potential or the L level (low potential) or H level (high potential) of a signal.

[0135] The FNC2 signal connected to TA15 (DATA contact) is an audio data signal (DATA) and is output from accessory 200 to camera 100.

[0136] The FNC3 signal connected to TA16 (LRCLK contact) is the audio channel clock signal (LRCLK), and is the signal output from accessory 200 to camera 100.

[0137] The FNC4 signal connected to TA17 (BCLK contact) is the audio bit clock signal (BCLK), which is output from camera 100 to accessory 200.

[0138] In this embodiment, as described above, the sampling frequency is 48kHz and the resolution is 32bit, so the frequency of LRCLK is 48kHz and the frequency of BCLK is 3.072MHz. The maximum frequency of DATA is 1.536MHz, which is half the period of CLK.

[0139] In this embodiment, the contact arrangement is such that reference potential contacts TA18 and TC18, which are connected to the GND potential (reference potential), are located next to contacts TA17 and TC17, which are connected to the FNC4 signal (BCLK), the highest frequency of the functional signal contacts to which the functional signal is connected. Signal wiring to the axle interface is generally done using a flexible circuit board. In addition, to reduce product costs, the flexible circuit board may be single-sided, and the circuit board wiring is done in the same order as the contact arrangement. In this embodiment, the GND contact, which is the reference potential contact, is located next to the functional signal contact to which the signal with the highest frequency of the functional signal is connected. This makes it possible to suppress radiated noise (EMI) from the functional signal contacts, interference to signals connected to other contacts, and crosstalk with signals other than the I2S data bus.

[0140] In this embodiment, the contacts TA18 and TC18 adjacent to contacts TA17 and TC17, to which the FNC4 signal (BCLK), which has the highest frequency, is connected, are connected to the reference potential, GND. However, the effect can be obtained by connecting to a stable reference potential other than GND, not limited to this.

[0141] Figure 8(b) shows an example of a configuration where the audio data is increased compared to Figure 8(a). The purpose of increasing the audio data is to increase the number of channels or the resolution.

[0142] The FNC4 signal connected to TA17 is the audio bit clock signal (BCLK), and is the same as in Figure 8(a).

[0143] On the other hand, the FNC3 signal connected to TA14 is the audio channel clock signal (LRCLK), which is the signal output from accessory 200 to camera 100.

[0144] The FNC2 signal connected to TA15 is an audio data signal (DATA2), which is output from accessory 200 to camera 100. The FNC1 signal connected to TA16 operates as an audio data signal (DATA2), which is output from accessory 200 to camera 100.

[0145] Thus, when adding audio data signals to increase the amount of audio data, and using a configuration with two signals, arranging the signals with higher frequencies closer to the GND terminal can result in a configuration that is relatively more effective at preventing crosstalk.

[0146] Figure 8(c) shows an example of the configuration of the functional circuit 206 when the accessory 200 is a strobe device. The light emission circuit 206B1 within the functional circuit 206 is a strobe light emission circuit composed of IGBTs, trigger coils, etc., and controls the emission of light from the light emission unit 206B2. The light emission unit 206B2 is composed of a xenon tube, etc., and emits illumination light that is projected onto the subject. The charging circuit 206B3 is composed of a transformer, switching FET, capacitor, etc., and stores charge to cause the light emission unit 206B2 to emit light.

[0147] The FNC1 signal connected to TA14 is a flash synchronization signal (STARTX) used to control the flash timing of the flash unit 206B2, and is output from camera 100 to accessory 200. The FNC2 to FNC4 signals are not used in strobe equipment, and no signals are connected to these contacts.

[0148] In this embodiment, unused functional signal contacts are left unconnected (OPEN). However, this is not the only option; they may also be connected to a stable reference potential, such as the power supply potential or the low or high level of the signal, in accordance with the connection destinations of contacts TC15 to TC17, which are the connection destinations of contacts TA15 to TA17.

[0149] In strobe equipment, only the FNC1 signal is used among the functional signals. Furthermore, although the flash synchronization signal (STARTX) is not a periodically occurring signal, when connecting microphone equipment, the camera 100 assigns GND to the FNC1 signal, thus keeping the configuration of the camera control circuit 101 simple.

[0150] The following describes further features of the contact arrangement in this embodiment. SDA (first signal), connected to contacts TC12 and TA12 as the first signal contacts, and SCL (second signal), connected to contacts TC13 and TA13 as the second signal contacts, are both signals for I2C communication. These signals are transmitted by open-drain communication. Since both SDA and SCL are pulled up to the camera microcontroller power supply VMCU_C, they are signals with relatively high impedance when in communication standby mode and are susceptible to crosstalk.

[0151] Therefore, in this embodiment, the communication request signal (fourth signal) / WAKE is assigned to contacts TC11 and TA11, which are fourth signal contacts adjacent to the SDA contacts TC12 and TA12. As mentioned above, the communication request signal / WAKE is a signal that requests communication from the accessory 200 to the camera 100.

[0152] Figure 15(a) shows the timing of when accessory 200 sends a communication request to camera 100 and performs I2C communication. As shown in Figure 15(a), the communication request signal / WAKE is Before I2C communication via SCL and SDA, the signal level changes from Hi to Lo. This is because I2C communication is performed in response to this change. Therefore, by placing the communication request signal / WAKE contacts TC11 and TA11 adjacent to the SDA contacts and SDA contacts for I2C communication, crosstalk between the communication request signal / WAKE and the SDA can be prevented.

[0153] Furthermore, as shown in Figure 15(a), by controlling the signal level of the communication request signal / WAKE to change from a low level to a high level after I2C communication, crosstalk between the communication request signal / WAKE and the SDA can be prevented.

[0154] Furthermore, the FNC1 signal is assigned to contacts TC14 and TA14, which are third signal contacts adjacent to the SCL contacts TC13 and TA13. As mentioned earlier, in microphone equipment, GND is assigned to the FNC1 signal, so crosstalk with respect to SCL can be prevented.

[0155] Furthermore, in strobe equipment, the flash synchronization signal (STARTX: the third signal) as the FNC1 signal is assigned to contacts TC14 and TA14, which are adjacent to the SCL contacts TC13 and TA13. Figure 15(b) shows the timing of communication requests from accessory 200 to camera 100, and the timing of I2C communication and flash firing. As shown in Figure 15(b), during the timing (period) when the flash synchronization signal is output, I2C communication is not performed between camera 100 and accessory 200 in order to prioritize the control of flash firing. In other words, the flash synchronization signal is a signal whose signal level changes before (or after) I2C communication, but whose signal level does not change during I2C communication. This prevents crosstalk of the flash synchronization signal to SCL.

[0156] Thus, in this embodiment, a STARTX contact is placed on one of the two adjacent sides of the SDA and SCL contacts, and a / WAKE contact is placed on the other side, thereby enabling good I2C communication.

[0157] Furthermore, in this embodiment, the communication request signal / WAKE connected to contacts TC11 and TA11 adjacent to the SDA contacts TC12 and TA12 is also an open-drain signal, similar to the SDA. Compared to the case where the communication request signal / WAKE is a push-pull signal, crosstalk to the SDA when the signal level of the communication request signal / WAKE changes can be suppressed.

[0158] The SCLK connected to the SCLK contacts TC07 and TA07 is the clock signal for SPI communication, and in this embodiment, it operates at a drive frequency of 1 MHz. In this embodiment, the attachment detection contacts TC06 and TA06 adjacent to the SCLK contacts TC07 and TA07 are used to transmit the accessory attachment detection signal / ACC_DET. As mentioned earlier, the accessory attachment detection signal / ACC_DET is a signal that becomes at a potential equivalent to GND when the accessory 200 is attached to the camera 100. Therefore, by arranging the contacts in this way, crosstalk between SCLK and signals other than the SPI bus can be prevented.

[0159] The MOSI connected to the other adjacent contacts TC08 and TA08 of the SCLK contacts TC07 and TA07 is a data signal transmitted from the camera control circuit 101 to the accessory control circuit 201 via SPI communication. Generally, the timing of the change in the output level of MOSI in SPI communication is synchronized with the timing of the change in the output level of SCLK. Therefore, by placing the MOSI contacts TC08 and TA08 next to the SCLK contacts TC07 and TA07, crosstalk between SCLK and MOSI can be suppressed.

[0160] The MISO signals connected to the adjacent contacts TC09 and TA09, which are next to the MOSI contacts TC08 and TA08, are data signals transmitted from the accessory control circuit 201 to the camera control circuit 101 in SPI communication. Generally, the timing of the change in the output level of MISO in SPI communication is synchronized with the timing of the change in the output level of SCLK, similar to MOSI. Therefore, by placing the MISO contacts TC09 and TA09 next to the MOSI contacts TC08 and TA08, crosstalk between MOSI and MISO can be suppressed.

[0161] The CS contacts connected to the other adjacent contacts TC10 and TA10 of the MISO contacts TC09 and TA09 are communication request signals transmitted from the camera control circuit 101 to the accessory control circuit 201 during SPI communication. Generally, in SPI communication, the CS maintains a constant output level from the time the communication request is made until the communication is completed. Therefore, by placing the CS contacts TC10 and TA10 next to the MISO contacts TC09 and TA09, crosstalk to the MISO can be suppressed.

[0162] The communication request signal / WAKE, connected to the other adjacent contacts TC11 and TA11 of the CS contacts TC10 and TA10, is a signal that requests communication from the accessory control circuit 201 to the camera control circuit 101. As explained earlier, the communication request signal / WAKE is an open-drain signal and is therefore relatively susceptible to crosstalk. For this reason, in this embodiment, by placing the CS contacts TC10 and TA10, which have a relatively low frequency of signal level changes, adjacent to the communication request signal / WAKE contacts TC11 and TA11, crosstalk to the communication request signal / WAKE can be suppressed.

[0163] Furthermore, differential signals requiring impedance control are connected to contacts TC01~TC03, TA01~TA03 and contacts TC19~TC21, TA19~TA21, located at both ends and near the camera connection section 141 and accessory connection section 211 (hereinafter collectively referred to as the "ends side"). Signal wiring to the axle interface is generally configured using a flexible circuit board. In order to achieve the desired wiring impedance with a flexible circuit board, it is necessary to maintain a constant distance between differential signal lines and parallel wiring to GND. Also, in the case of double-sided boards, it is common to form a mesh-like GND wiring on the back side of the differential signal. Thus, signal wiring requiring impedance control has relatively greater constraints on wiring design compared to general single-ended signals.

[0164] In contrast, in this embodiment, differential signals requiring impedance control are connected to contacts located at both ends of the camera connection section 141 and the accessory connection section 211, thereby reducing their interaction with other signals and increasing the flexibility of the wiring design.

[0165] Furthermore, differential signals enable high-speed data transfer of several hundred Mbps to several Gbps, similar to USB and PCIe, making them suitable for transferring large amounts of data between devices. On the other hand, some types of Accessory 200 do not use differential signals. In such accessories that do not use differential signals, the contacts assigned to differential signals are unnecessary, so removing these contacts can reduce the cost of the accessory.

[0166] Figure 12 shows an example of a modified configuration of the accessory 200 shown in Figure 1. Specifically, it has a configuration that omits contacts TA01~TA03, TA19~TA21 and the signals and circuits connected to them. That is, the accessory 200 in Figure 12 has 15 contacts. In the configuration of Figure 12, differential signals are assigned to contacts TC01~TC03 and TC19~TC21 located on both ends of the camera connection section 141. On the other hand, in the accessory 200 where differential signals are not required, the contacts for differential signals in the accessory connection section 211 are eliminated, and a contact arrangement is adopted that includes only the contacts necessary for the accessory 200.

[0167] Furthermore, in the accessory 200 shown in Figure 12, the contacts TC04, TA04 and TC18, TA18 near both ends of the camera connection section 141 and accessory connection section 211 are designated as GND contacts. By arranging the contacts in this way, even in the accessory 200 which is connected to some of the contacts of the camera connection section 141, the contacts at both ends of the accessory connection section 211 can be designated as GND contacts. This prevents the GND contacts from separating even if excessive static pressure or shock is applied to the accessory 200.

[0168] Up to this point, we have described the case where accessory 200 is directly attached to camera 100. Next, using Figure 13, we will describe the case where an intermediate accessory 400 is attached between camera 100 and accessory 200. The configuration of camera 100 and accessory 200 is as described above. Examples of intermediate accessories 400 include extension cables to extend the distance between camera 100 and accessory 200, and adapters for attaching multiple accessories to camera 100 simultaneously. In this embodiment, we will describe the case where the intermediate accessory 400 is an extension cable. In the configuration of Figure 13, the intermediate accessory 400 corresponds to an accessory, and accessory 200 corresponds to other accessories.

[0169] The intermediate accessory 400 has a camera shoe and an accessory shoe that can be attached to the camera 100 and the accessory 200 respectively, and each is provided with a camera-side intermediate connection part 311 and an accessory-side intermediate connection part 312. The camera-side intermediate connection part 311 has 21 contacts TM01 to TM21 arranged in a row and is a connector for making an electrical connection with the camera 100. Each of the contacts TM01 to TM21 makes one-to-one contact with the contacts TC01 to TC21 in the camera connection part 141.

[0170] On the other hand, the accessory-side intermediate connection section 312 has 21 contacts TN01 to TN21 arranged in a row and is a connector for making an electrical connection with the accessory 200. Each of the contacts TN01 to TN21 makes one-to-one contact with the contacts TA01 to TA21 in the accessory connection section 211.

[0171] By arranging the contacts in this way in the intermediate accessory 400, power supply and communication can be performed in the same way as when the accessory 200 is directly attached to the camera 100. In this case, the intermediate accessory 400 may receive power from the camera 100, or it may transmit the power supply from the camera 100 directly to the accessory 200. Power supply in this embodiment also includes cases where the intermediate accessory 400 is not supplied with power, such as when the power supply from the camera 100 is transmitted directly to the accessory 200.

[0172] In Figure 13, the number of contacts in the camera-side intermediate connection section 311 is the same as the number of contacts in the camera connection section 141, and the number of contacts in the accessory-side intermediate connection section 312 is the same as the number of contacts in the accessory connection section 211. However, it is not necessary for each to have the same number of contacts.

[0173] Figure 14 shows an example where the configuration of accessory 200 and intermediate accessory 400 has been changed from the configuration in Figure 13. Differential signals are connected to contacts TC01~TC03 and TC19~TC21 on both ends of the camera connection part 141, but depending on the function of accessory 200, differential signals may not be necessary. In the configuration of Figure 14, the contacts to which differential signals are connected from the camera-side intermediate connection part 311 and the accessory-side intermediate connection part 312 to the accessory connection part 211 have been eliminated. In other words, the intermediate accessory 400 and accessory 200 in Figure 14 each have 15 contacts. This adopts a contact arrangement that includes only the contacts necessary for the intermediate accessory 400 and accessory 200.

[0174] Next, we will describe in detail the connection structure between the camera 100 and an external flash unit 120, which is an example of an accessory 200.

[0175] Figure 16(a) shows the camera 100 viewed from the rear at an angle. Figure 16(b) shows how to attach the external flash unit 120 to the accessory shoe 1123 of the camera 100. Figure 16(c) shows the camera 100 with the external flash unit 120 attached, viewed from the rear at an angle.

[0176] The imaging optical system is located on the front side (field of view side) of the camera 100, and the image display unit 107 is located on the rear side of the camera 100. A top cover 150, which serves as an exterior component, is provided on the top surface of the camera 100, and an accessory shoe 1123 is mounted on the top cover 150. On the other hand, in the external flash unit 120, the camera connection part 216 is located at the bottom of the external flash unit 120. As shown in Figure 16(b), the external flash unit 120 is slid parallel to the front side in the Z direction (the mounting side in the first direction) relative to the camera 100, engaging the camera connection part 216 and the accessory shoe 1123. This allows the external flash unit 120 to be attached to the camera 100. The front side in the Z direction is the direction from the back side of the camera 100 toward the front side, that is, the direction from the image display unit 107 side toward the imaging optical system 122 side. Note that the X direction (second direction), Y direction (third direction), and Z direction (front-back direction) shown in Figures 16 and later are common. The X direction is the direction perpendicular to the Z direction in the horizontal plane when the Z direction is parallel to the horizontal direction, and is the width direction of the camera 100. The Y direction is the direction perpendicular to the Z direction and the X direction, and is the height direction of the camera 100.

[0177] Next, the accessory shoe 1123 of the camera 100 will be described in detail. Figure 17(a) shows the top cover 150 and the disassembled accessory shoe 1123. Figure 17(b) shows the assembled accessory shoe 1123. The mounting direction of the accessory shoe 1123 to the top cover 150 is the Y direction.

[0178] The accessory shoe 1123 includes an engaging member 151, a connection terminal connector 152, a shoe stage 153, and an accessory shoe spring 154. The engaging member 151 is a member for holding the external flash unit 120 by engaging with the external flash unit 120. The connection terminal connector 152 has a plurality of connection terminals 152a arranged at equal pitches in the X direction on a connector base member 152e, which is a holding member made of resin material or the like, and held by the connector base member 152e. The connection terminals 152a correspond to the contacts TC01 to TC21 of the camera connection part 141 shown in Figure 1.

[0179] In the connection terminal connector 152, the connection terminal 152a is positioned forward in the Z direction (towards the front of the camera 100), which is the mounting direction of the external flash unit 120, as shown in Figure 17(b). On the rear side of the connection terminal connector 152 in the Z direction (towards the back of the digital camera 100), there is an engagement hole 156 that engages with the lock pin 252 of the external flash unit 120, as shown in Figure 19(a).

[0180] When the external flash unit 120 is attached to the accessory shoe 1123, the connection terminal 152a is electrically connected to the external flash unit 120. In addition, each of the multiple connection terminals 152a is electrically connected to a flexible circuit board 158 located on the lower side in the Y direction of the top cover 150. The flexible circuit board 158 is connected to the main circuit board of the camera 100 (not shown). Therefore, when the external flash unit 120 is attached to the accessory shoe 1123, communication becomes possible between the external flash unit 120 and the camera 100.

[0181] The shoe stage 153 is a housing member that surrounds the engaging member 151 and the connection terminal connector 152. The accessory shoe holding member 155 is a structural frame that holds the engaging member 151. As shown in Figure 17(a), the accessory shoe holding member 155, the flexible substrate 158, the top cover 150, the shoe stage 153, and the connection terminal connector 152 are fastened to the engaging member 151 by four screws 157 that pass through them. This positions and fixes these members relative to each other. By arranging the four screws 157 one in each of four equally divided regions in the X and Z directions, the above members can be joined in a balanced manner.

[0182] Figure 18(a) shows the structure of the upper side of the engaging member 151, and Figure 18(b) shows the structure of the lower side of the engaging member 151. Figure 18(c) shows the structure of the upper side of the connection terminal connector 152. Figure 24 shows the accessory shoe 1123 as viewed from the insertion direction of the external flash unit 120.

[0183] The engaging member 151 is formed by bending a metal plate into a loop shape, so that the end faces of both bent ends abut each other at the joint 151a. The engaging member 151 has a pair of engaging portions 151b and a connecting portion 151c that connects the pair of engaging portions 151b to each other. The engaging member 151 has a pair of first screw holes 151d and a pair of second screw holes 151e used for fastening screws 157. The engaging member 151 also has an engaging hole 156 that engages with the lock pin 252 of the external flush unit 120.

[0184] As shown in Figures 18(a) and 12, the pair of engaging portions 151b are spaced apart in the X direction by a first width (hereinafter referred to as the engaging portion spacing) of 151aa. The retaining member 254 of the external flash unit 120, described later and shown in Figure 19(b), is inserted into the engaging portion spacing 151aa. The pair of first screw holes 151d are provided at a predetermined interval in the X direction and function as a pair of first fastening holes spaced apart from each other in the X direction on the rear side in the Z direction (back side). The pair of second screw holes 151e are provided at a predetermined interval in the X direction and function as a pair of second fastening holes spaced apart from each other in the X direction on the front side in the Z direction. The engaging hole 156 is formed in a region sandwiched between the pair of first screw holes 151d and is positioned to engage with the lock pin 252 of the external flash unit 120.

[0185] As shown in Figures 17(b) and 18(c), multiple connection terminals 152a are exposed in the connection terminal connector 152. In the pitch direction (X direction) where the multiple connection terminals 152a are aligned, the position of the camera connection portion 216 is determined by the spacing 151aa of the engagement portions of the engagement member 151. Therefore, the holding member 254 of the external flash unit 120 is positioned relative to the connection terminal connector 152 by the engagement member 151.

[0186] Furthermore, on the front side in the Z direction of the connection terminal connector 152 (connector base member 152e), which is an example of the camera connection part 141 shown in Figure 1, contact surfaces and grooves are formed on both sides in the X direction, flanking the multiple connection terminals 152a, as shown in Figure 24. Specifically, a contact surface 152b is formed to contact and position the accessory shoe 1123 in the Z direction when the external flash unit 120 is attached, and a groove 152c is formed into which the accessory shoe 1123 is inserted. Each groove 152c is formed to extend from the contact surface 152b toward the front side in the Z direction (attachment side), and is provided with a slanted surface 152d that faces inward and diagonally upward (having an inclination with respect to the X direction). The portion of the groove 152c above the slanted surface 152d extends outward in the X direction from the position of the upper end of the slanted surface 152d. This is to prevent sink marks from forming in the sloped portion 152d during resin molding, as forming the sloped portion 152d up to the upper end of the groove 152c would cause depressions (shrinkage marks) in the sloped portion 152d.

[0187] As shown in Figure 24, in the X direction, the outermost inner surface 152ccc of the groove 152c in the connector base member 152e of the accessory shoe 1123 is located outside the inner end faces (interaction distance 151aa) of the pair of engagement portions 151b of the engagement member 151, and inside the outermost inner surface 151bb of the engagement member 151.

[0188] The inclination start position 152cc, which is the end (lower end) of the inclined surface 152d on the bottom side of the groove 152c, is located inside the engagement portion spacing 151aa. This ensures that a region is provided for the contact surface 152b, which contacts the contact portion 251b of the camera connection portion 216 (described later) to perform positioning in the Z direction. Furthermore, by providing an inclined shape starting from the inclination start position 152cc, the space into which the shoe device of the external flash unit 120 (camera connection portion 216, described later) is inserted can be widened, and the degree of freedom in the shape of the shoe device can also be ensured. As a result, a shape that adequately protects the connection terminals can be formed on the shoe device of the external flash unit 120.

[0189] Next, the external flash unit 120 will be described. Figure 19(a) shows the external flash unit 120 as seen from the camera connection part 216 side (downward in the Y direction). Figure 19(b) shows a cross-section along line AA in Figure 19(a) and shows the internal structure of the camera connection part 216. Figure 20(a) shows the camera connection part 216. However, the base part 250 and lock lever 253, which will be described later, are not shown. Figure 20(b) shows the camera connection part 216 as seen from the front in the Z direction.

[0190] The camera connection section 216 is located on the lower side in the Y direction (upper side in Figure 19(a)) of the base section 250 of the external flash unit 120 when the camera 100 is mounted on the accessory shoe 1123, as shown in Figure 19(b). The camera connection section 216 includes a shoe mounting leg (engaging member, shoe plate) 251, a locking pin 252, a locking lever 253, a retaining member 254, a connecting plug 256, and a Y-direction retaining member 258.

[0191] The shoe mounting leg 251 is an engaging member that engages with and holds the external flash unit 120 to the accessory shoe 1123 of the camera 100. In other words, the shoe mounting leg 251 is an engaging member on the external flash unit 120 side that is detachable from the engaging member 151 of the accessory shoe 1123.

[0192] The accessory shoe 1123 and the camera connection part 216 are subjected to significant stress due to the pressure required to maintain the mounted state and external forces (such as impacts) acting on the external flash unit 120. The shoe mounting leg 251 is manufactured by processing a metal plate (sheet metal) to ensure high mechanical strength against such large stresses.

[0193] The locking pin 252 is a component that prevents the external flash unit 120 from falling off when the camera connection part 216 (shoe mounting leg 251) is attached to the accessory shoe 1123, and is held on the shoe mounting leg 251 so as to be movable in the Y direction. Specifically, the locking pin 252 is held so as to be slidable in the Y direction by a Y-direction holding member 258. The locking lever 253 and the Y-direction holding member 258 are held by a holding member 254.

[0194] When the external flash unit 120 is mounted on the accessory shoe 1123 and the lock lever 253 is rotated, a cam (not shown) moves the Y-direction holding member 258 downward in the Y direction in Figure 19(b). At the same time, the lock pin 252 also moves downward in the Y direction in Figure 19(b) along with the Y-direction holding member 258. As a result, the lock pin 252 protrudes from the shoe mounting leg 251 and engages with the engagement hole 156 provided in the engagement member 151 of the accessory shoe 1123. The lock pin 252 and the engagement hole 156 function as positioning members in the Z direction to ensure electrical connection between the external flash unit 120 and the camera 100.

[0195] The connection plug 256, an example of the accessory connection part 211 shown in Figure 1, is provided on the front side in the Z direction of the camera connection part 216, is made of a non-conductive material (dielectric material) such as resin, and is integrated with the retaining member 254. The outermost width T of the connection plug 256 in the X direction is narrower than the width W of the shoe mounting leg 251 in the X direction. This ensures that there is a region for providing a contact portion 251b on the shoe mounting leg 251. The connection plug 256 has a plurality of connection terminals 257 for communication by contacting a plurality of connection terminals 152a of the accessory shoe 1123 shown in Figure 18(c). The connection terminals 257 correspond to the contacts TA01 to TA21 of the accessory connection part 211 shown in Figure 1.

[0196] Multiple connection terminals 257 are provided in a one-to-one correspondence with multiple connection terminals 152a, and are held by a holding member 254 so as to extend in the Z direction and be aligned in the X direction. Each connection terminal 257 has a tip portion 257a that contacts the corresponding connection terminal 152a. Each connection terminal 257 also has an extension portion 257b that extends backward in the Z direction from the tip portion 257a, and when the tip portion 257a comes into contact with the connection terminal 152a, it displaces the tip portion 257a upward in the Y direction in Figure 19(b) by elastic deformation. An extension portion 257c extending upward in the Y direction is formed at the rear end in the Z direction of the extension portion 257b. At the upper end of the extension portion 257c, there is a flexible substrate connection portion 257d that is connected to a main substrate (not shown) of the external flash unit 120 and connected to a flexible substrate 259 inserted into the holding member 254 from the upper side in the Y direction.

[0197] Furthermore, the extendable portion 257b has a stepped portion 257e formed in the middle of the Z-direction, which has a step in the Y-direction. As mentioned above, the extendable portion 257b is elastically deformable in the Y-direction. However, if the distance L of the extendable portion 257b in the Z-direction is short, sufficient deformation cannot be obtained, reducing durability. As a result, repeated attachment and detachment of the connection terminal 152a and the tip portion 257a may cause the extendable portion 257b to be easily damaged. Therefore, by providing the stepped portion 257e on the extendable portion 257b, a sufficient distance L is ensured without interfering the extendable portion 257b with the shoe mounting leg 251.

[0198] As shown in Figures 20(a) and (b), the connector plug 256 is provided with a pair of projections 256a at both ends in the X direction, projecting downwards in the Y direction (a third direction) so as to sandwich a plurality of connector terminals 257 between them. As shown in Figure 20(b), the lower tip 256d of each projection 256a protrudes below the line connecting the lower ends of the tip 257a of the connector terminals 257 in order to protect the connector terminals 257 from external forces such as pressure and impact. In other words, the tip 257a of the connector terminal 257 is located above (inward) the line connecting the lower tip 256d of the pair of projections 256a.

[0199] Furthermore, each projection 256a is provided with a slanted surface 256b on its outer side (outer surface) in the X direction, extending diagonally upward from the lower tip 256d and facing diagonally downward, i.e., having an inclination with respect to the X direction. Because each projection 256a has this shape, the connecting plug 256 can be inserted into the groove 152c having the slanted surface 152d in the connecting terminal connector 152.

[0200] The inclined surface 256b serves to release external forces such as pressure and impact applied to the connecting plug 256, thereby preventing damage to the connecting plug. For example, Figure 20(c) shows the case where an external force is applied to the connecting plug 256 from the X direction. Figure 20(c) shows the connecting plug 256 as viewed from the front in the Z direction.

[0201] Let F1 be the external force from the X direction, and define it as a vector. When the external force F1 acting on the inclined surface 256b is decomposed according to the rules of addition in vector space, it is decomposed into a component force F2 in the direction along the inclined surface 256b and a component force F3 in the direction perpendicular to the inclined surface 256b. If the angle between the external force F1 and the inclined surface 256b is θ, then the component forces F2 and F3 can be found by the following equation (1). F2 = F1cosθ F3 = F1sinθ (1) If a sloped section 256b is provided, then θ will be 0° < θ < 90°. Within this range, F2 <F1 F3 <F1(2) As a result, since component force F2 escapes in the direction along the slope 256b, only component force F3 is the force that affects the connecting plug 256. As mentioned above, since component force F3 is smaller than the external force F1, the connecting plug 256 can be prevented from being damaged even if a sufficiently large external force is applied.

[0202] By forming the inclined surfaces 256b on both sides in the X direction such that their width in the X direction narrows as they move downwards in the Y direction, it is possible to release a portion of the external force not only from the X direction but also from the downwards in the Y direction.

[0203] Figure 25 shows an enlarged view of a portion of the connecting plug 256 as seen from the Z direction. In the Y direction, B is the height from the lower tip 256d of the projection 256a to the upper surface of the connecting plug 256 (the height of the connecting plug including the projection), and A is the height of the inclined portion 256b from the lower tip 256d (inclined start position 256c) to the upper end of the inclined portion 256b. In this case, A is preferably 1 / 5 or more of B, and more preferably 1 / 4 or more, 1 / 3 or more, or half or more as shown in Figure 13. That is, the inclined portion 256b is formed to have dimensions that are significant for the function of releasing external forces from the X direction, and is different from the chamfer shape generally provided at the corners of projections. Furthermore, the inclination angle θ of the inclined portion 256b with respect to the X direction is preferably set in the range of 45°±20° for the function of releasing the external forces mentioned above.

[0204] In order to ensure a sufficient contact area 251b on the shoe mounting leg 251 with respect to the contact surface 152b of the accessory shoe 1123, which is the Z-direction positioning part, it is desirable to make the width in the X direction between the inclined start positions 256c at the lower tip 256d of the inclined portions 256b on both sides as short as possible. In this embodiment, the width in the X direction between the inclined start positions 256c is set to be inside the width V in the X direction of the holding member 254, thereby ensuring a sufficient contact area 251b.

[0205] The camera connection section 216 has a structure in which the shoe mounting leg 251 and the retaining member 254 are fastened together. Details of this fastening structure will be described later.

[0206] The retaining member 254 is insertable into the engagement gap 151aa of the engagement member 151 of the accessory shoe 1123 shown in Figure 18(a), and has a connecting portion 254a with a width V shorter than the width W of the shoe mounting leg 251 in the X direction. The dimensions of width W and width V are specified in Japanese Industrial Standard (JIS) B7101-1975 "Accessory mounting base and mounting leg for camera". The position of the external flash unit 120 relative to the camera 100 in the X direction is determined by the fitting of the connecting portion 254a with the engagement member 151. In addition, the shoe mounting leg 251 is biased upward in the Y direction by contacting the elastically deformed portion 154a of the accessory shoe spring 154, which acts as a biasing member as shown in Figures 17(a) and (b). As a result, the upper surface of the shoe fitting portion 251a contacts (pressures) the lower surface of the engagement member 151, and the position of the external flash unit 120 relative to the camera 100 in the Y direction is determined.

[0207] Furthermore, the contact portion 251b of the shoe mounting leg 251 comes into contact with the contact surface 152b on the front side in the Z direction of the connection terminal connector 152, thereby determining the position of the external flash unit 120 relative to the camera 100 in the Z direction.

[0208] Furthermore, the retaining member 254 is also a structure for connecting the shoe mounting leg 251 and the base portion 250, and the locking pin 252 and the connecting terminal 257 are located inside the connecting portion 254a.

[0209] Next, the fastening structure between the retaining member 254 and the shoe mounting leg 251 will be described. Figure 21(a) shows the camera connection portion 216 viewed from above in the Y direction, and Figure 21(b) shows the cross-section along the line B-B in Figure 21(a).

[0210] A pair of first screws 260a and a pair of second screws 260b, which are fastening members for fastening the shoe mounting legs 251 to the retaining member 254, pass through the retaining member 254 and are fastened to the shoe mounting legs 251. At this time, by arranging one screw in each of four regions that are divided almost equally in the X and Z directions in a balanced manner, the shoe mounting legs 251 are stably held by the retaining member 254. Furthermore, as mentioned above, the shoe mounting legs 251 are parts that are subjected to large stresses. For this reason, by fastening the metal shoe mounting legs 251 to the retaining member 254 with a balanced pair of first screws 260a and a pair of second screws 260b, it is possible to ensure the necessary mechanical strength.

[0211] As shown in Figure 21(b), multiple connection terminals 257 are arranged in the region S sandwiched between the pair of first screws 260a and the pair of second screws 260b. Furthermore, the width between the pair of first screws 260a and the pair of second screws 260b is narrower than the width between the lower tip portions 256d of the projections 256a of the connection plug 256, the width V of the retaining member 254, the outermost width T of the connection plug 256, and the width W of the shoe mounting leg 251.

[0212] Figure 26 shows a cross-section of the accessory shoe 1123 with the camera connection part 216 attached, viewed from the Z direction. This figure shows the dimensions T and V of the camera connection part 216 and the positional relationship between each part of the camera connection part 216 and each part of the accessory shoe 1123.

[0213] In Figure 26, as described above, the upper surface of the shoe fitting portion 251a of the camera connection portion 216 is in contact with the lower surface (ceiling surface) of the engaging member 151 of the accessory shoe 1123 for positioning in the Y direction.

[0214] On the other hand, the lower tip 256d and the slanted surface 256b of the projection 256a and the connecting plug 256 in the camera connection section 216 do not come into contact with the bottom surface and slanted surface 152d of the groove 152c of the accessory shoe 1123, respectively. The gap between the lower tip 256d of the projection 256a and the bottom surface of the groove 152c of the accessory shoe 1123 is set to be as small as possible. As a result, when an external force in the X direction is applied to the external flash unit 120, the lower tip 256d of the projection 256a can come into contact with the bottom surface of the groove 152c of the accessory shoe 1123, thereby reducing the floating of the connecting plug 256 (tilting relative to the accessory shoe 1123).

[0215] Furthermore, the gaps between the inclined surfaces 256b and 152d, and the gap between the inner end surface 152ccc of the groove 152c and the outer end surface of the connecting plug 256 are set to be somewhat large. This prevents the connecting terminals 257 and 152a from being subjected to load when an external force in the X direction is applied to the external flash unit 120.

[0216] Furthermore, in the groove 152c of the accessory shoe 1123, the relationship between the height of the groove 152c in the Y direction (the height from the bottom surface of the groove 152c to the top surface of the engaging member 151) and the height of the inclined surface 152d in the Y direction is the same as the relationship between the height B of the connecting plug 256 and the height A of the inclined surface 256b in the camera connection part 216. In addition, it is preferable to set the inclination angle of the inclined surface 256b with respect to the X direction to a range of 45°±20°, similar to the inclination angle θ of the inclined surface 256b in the camera connection part 216.

[0217] In the above embodiments, the case where the surface shape of the inclined portion 256b provided on the projection 256a is flat was described, but the inclined portion 256b may be a curved surface with curvature. That is, the inclined portion 256b may be a surface that is inclined with respect to the X direction.

[0218] According to the above embodiment, in the small camera connection part 216 and accessory shoe 1123, it is possible to secure areas for providing a larger number of connection terminals and shapes to protect them than in the conventional method, as well as areas for positioning components.

[0219] Next, a modified example of the external flash unit 120 will be described. Figure 22(a) shows the external flash unit 120 as viewed from the camera connection part 216 side (downward in the Y direction). Figure 22(b) shows a cross-section along line AA in Figure 22(a) and shows the internal structure of the camera connection part 216. Figure 23(a) shows the camera connection part 216. However, the base part 250 and the lock lever 253 are not shown. Figure 23(b) shows the camera connection part 216 as viewed from the front in the Z direction.

[0220] The camera connection section 216 is located on the lower side in the Y direction (upper side in Figure 22(a)) of the base section 250 of the external flash unit 120 when the camera 100 is mounted on the accessory shoe 1123, as shown in Figure 22(b). The camera connection section 216 includes a shoe mounting leg 300a, a locking pin 252, a locking lever 253, a retaining member 300, a connecting plug 300b, a Y-direction retaining member 258, and a shoe cover 301.

[0221] The shoe mounting leg 300a is an engaging member for engaging the external flash unit 120 with the accessory shoe 1123 of the camera 100, similar to the shoe mounting leg 251 in the previously described embodiment. In other words, the shoe mounting leg 300a is an engaging member on the external flash unit 120 side that is detachable from the engaging member 151 of the accessory shoe 1123.

[0222] In the embodiment described above, prioritizing mechanical strength, the shoe mounting leg 251, which is a metal shoe plate, and the holding member 254, which is made of resin, were formed as separate components. In contrast, in the modified example, the shoe mounting leg 300a and the holding member 300 are formed as a single unit from a resin material (non-conductive material). As a result, the pair of first screws 260a and the pair of second screws 260b in the previous embodiment are no longer needed, and the space for arranging the connection terminals 257 is increased, allowing for the arrangement of a larger number of connection terminals 257. Consequently, the external flash unit 120 can communicate more information with the camera 100 via the camera connection part 216 and the accessory shoe 1123.

[0223] The connection plug 300b is provided on the front side in the Z direction of the camera connection portion 216, and in this embodiment, it is formed as an integral member with the retaining member 300, which is made of a non-conductive resin material. Similar to the embodiment described above, the outermost width T of the connection plug 300b in the X direction is made narrower than the width W of the shoe mounting leg 300a in the X direction, thereby securing an area on the shoe mounting leg 300a where the contact portion 300e is provided. The connection plug 300b has a plurality of connection terminals 257 for contacting and communicating with a plurality of connection terminals 152a of the accessory shoe 1123 shown in Figure 18(c). The shoe cover 301 is an enclosure attached to the retaining member 300 and is a member that protects the plurality of connection terminals 257. The shape of the connection terminals 257 is the same as in the previous embodiment, and a stepped portion 257e is provided to ensure a sufficient distance L in the Z direction of the extended portion 257b without interfering with the shoe cover 301.

[0224] The shape of the connector plug 300b is the same as that of the connector plug 256 in the previous embodiment. The connector plug 300b is provided with a pair of projections 300c that protrude downward in the Y direction at both ends in the X direction, sandwiching a plurality of connector terminals 257. As shown in Figure 23(b), the lower tip 300k of each projection 300c protrudes below the line connecting the lower ends of the tip 257a of the connector terminal 257 in order to protect the connector terminal 257 from external forces such as pressure and impact. In other words, the tip 257a of the connector terminal 257 is located above (inward) the line connecting the lower tip 300k of the pair of projections 300c.

[0225] In this embodiment as well, each projection 300c is provided with a slanted portion 300f extending diagonally upward from the lower tip portion 300k and facing diagonally downward on its outer side in the X direction. Because each projection 300c has this shape, the connecting plug 300b can be inserted into the groove portion 152c having the slanted portion 152d in the connecting terminal connector 152 described in the previous embodiment. As explained in the previous embodiment, the slanted portion 300f serves to release external forces such as pressure and impact applied to the connecting plug 300b, preventing damage to the plug.

[0226] Furthermore, similar to the previous embodiment, it is desirable to make the distance in the X direction between the inclination start positions 300g at the lower tip portion 300k of the inclined portions 300f on both sides as short as possible. For this reason, the inclination start positions 300g on both sides are set inward from the width V of the holding member 254 in the X direction, thereby ensuring sufficient area for the contact portion 300e of the shoe mounting leg 300a.

[0227] The retaining member 300 is formed to be insertable into and engage with the engagement portion spacing 151aa of the engaging member 151 shown in Figure 18(a), and has a connecting portion 300h having a width V shorter than the width W of the shoe mounting leg 300a in the X direction. The widths W and V are specified in Japanese Industrial Standards (JIS) B7101-1975 "Mounting base and mounting foot for camera accessories," as in the previous embodiment. The position of the external flash unit 120 relative to the camera 100 is determined by the fitting of the connecting portion 300h with the engaging member 151. In addition, the shoe mounting leg 300a is biased upward in the Y direction by contacting the elastically deformed portion 154a of the accessory shoe spring 154 shown in Figures 17(a) and (b), so that the upper surface of the shoe fitting portion 300d contacts the lower surface of the engaging member 151. This determines the position of the external flash unit 120 relative to the camera 100 in the Y direction.

[0228] Furthermore, the contact portion 300e of the shoe mounting leg 300a comes into contact with the contact surface 152b on the front side in the Z direction of the connection terminal connector 152, thereby determining the position of the external flash unit 120 relative to the camera 100 in the Z direction. Furthermore, the retaining member 300 is also a structure for connecting the shoe mounting leg 300a and the base portion 250, and the locking pin 252 and the connecting terminal 257 are located inside the connecting portion 300h.

[0229] In this embodiment, we have described the case where the camera 100, accessory 200, and intermediate accessory 400 have 21 or 15 contacts, but the number of contacts may be other than these.

[0230] In this embodiment, accessories 200 were described as microphone equipment and strobe equipment, but the accessories referred to in this invention include various devices other than microphone equipment and strobe equipment, such as electronic viewfinder units. Also, in this embodiment, a camera was described as electronic equipment, but the electronic equipment referred to in this invention includes various electronic devices other than cameras. (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0231] The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention. [Explanation of Symbols]

[0232] 100 Cameras 101 Camera control circuit 131,132 Power supply circuit for accessories 141 Camera connection section 200 Accessories 211 Accessory connection section TC01~TC21, TA01~TA21 Contacts

Claims

1. An electronic device having an accessory that can be detachably attached, and having a plurality of contacts arranged in a row that are electrically connected to the accessory, The aforementioned plurality of contacts are Multiple functional signal contacts to which signals of different functions are connected according to the type of accessory, A reference potential junction to which the reference potential is connected, It includes a data communication contact and a clock signal communication contact, respectively, used for communication with the aforementioned accessory. The contact to which the signal with the highest frequency among the plurality of functional signal contacts is connected and the reference potential contact are arranged adjacent to each other. The contact to which the highest frequency signal is connected is located adjacent to the other contacts included in the plurality of functional signal contacts. No contact connected to the reference potential is located next to the other contacts mentioned above. An electronic device characterized in that the contact to which the highest frequency signal is connected is further away from the clock signal communication contact than the other contacts.

2. The electronic device according to claim 1, characterized in that the unused contacts among the plurality of functional signal contacts are connected to the reference potential.

3. The electronic device according to claim 1 or 2, characterized in that the reference potential is the ground potential, the power supply potential, or the low or high potential of the signal.

4. When the accessory is a microphone device, the functional signal contacts include a BCLK contact to which the audio bit clock signal in the Inter-IC Sound standard is connected, an LRCLK contact to which the audio channel clock signal is connected, and a DATA contact to which the audio data signal is connected. The electronic device according to any one of claims 1 to 3, characterized in that the reference potential contact is located next to one of the BCLK contacts, the LRCLK contact is located next to the other BCLK contact, and the DATA contact is located next to the LRCLK contact.

5. An accessory that is detachably attached to an electronic device and has multiple contacts arranged in a row that are electrically connected to the electronic device, The aforementioned plurality of contacts are Multiple functional signal contacts to which signals corresponding to the type of accessory are connected, A reference potential junction to which the reference potential is connected, It includes a data communication contact and a clock signal communication contact, respectively, used for communication with the aforementioned electronic device. The contact to which the signal with the highest frequency among the plurality of functional signal contacts is connected and the reference potential contact are arranged adjacent to each other. The contact to which the highest frequency signal is connected is located adjacent to the other contacts included in the plurality of functional signal contacts. No contact connected to the reference potential is located next to the other contacts mentioned above. An accessory characterized in that the contact to which the highest frequency signal is connected is further away from the clock signal communication contact than the other contacts.

6. The accessory according to claim 5, characterized in that the unused contacts among the plurality of functional signal contacts are connected to the reference potential.

7. The accessory according to claim 5 or 6, characterized in that the reference potential is the ground potential, the power supply potential, or the low or high potential of the signal.

8. The accessory is a microphone device, and the functional signal contacts include a BCLK contact to which the audio bit clock signal in the Inter-IC Sound standard is connected, an LRCLK contact to which the audio channel clock signal is connected, and a DATA contact to which the audio data signal is connected. The BCLK contact is the contact to which the signal with the highest frequency is connected. The accessory according to any one of claims 5 to 7, characterized in that the reference potential contact is located next to one of the BCLK contacts, the LRCLK contact is located next to the other BCLK contact, and the DATA contact is located next to the LRCLK contact.

9. The accessory according to claim 8, characterized in that a contact connected to the reference potential is arranged next to the DATA contact.

10. The accessory is a microphone device, and the functional signal contacts include a BCLK contact to which the audio bit clock signal in the Inter-IC Sound standard is connected, an LRCLK contact to which the audio channel clock signal is connected, and a DATA contact to which the audio data signal is connected. The BCLK contact is the contact to which the signal with the highest frequency is connected. The accessory according to any one of claims 5 to 7, characterized in that the reference potential contact is located next to one of the BCLK contacts, the DATA contact is located next to the other BCLK contact, and the LRCLK contact is located next to the DATA contact.

11. The accessory according to claim 10, characterized in that a contact connected to the reference potential is arranged next to the LRCLK contact.

12. The accessory is a microphone device, and the functional signal contacts include a BCLK contact to which the audio bit clock signal in the Inter-IC Sound standard is connected, an LRCLK contact to which the audio channel clock signal is connected, and a first DATA contact and a second DATA contact to which the audio data signal is connected. The BCLK contact is the contact to which the signal with the highest frequency is connected. The accessory according to any one of claims 5 to 7, characterized in that the reference potential contact is located next to one of the BCLK contacts, the first DATA contact is located next to the other of the BCLK contacts, the second DATA contact is located next to the first DATA contact, and the LRCLK contact is located next to the second DATA contact.

13. The accessory according to any one of claims 5 to 7, characterized in that the accessory is an intermediate accessory that is installed between the electronic device and other accessories.

14. An accessory characterized in that it has a contact used for communication with the electronic device via the intermediate accessory, with the accessory described in claim 13 as an intermediate accessory.

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