Electronic apparatus

Abstract

The present invention provides an electronic apparatus.　The electronic apparatus comprises: a connector connectable to an external apparatus; a first current detection circuit and a second current detection circuit that detect a current flowing between a power supply and the connector; and a conversion circuit that converts an analog value into a digital value. A first voltage value which is based on a current value detected by the first current detection circuit and a second voltage value which is based on a current value detected by the second current detection circuit are input to the conversion circuit.

Description

Electronic device

[0001] The present invention relates to an electronic device.

[0002] Patent Document 1 describes a camera system having a camera body and a photographing lens detachable from the camera body, and supplying power from the camera body to the photographing lens. The camera body includes a power source for supplying power to the photographing lens, a monitoring means for monitoring a supply voltage supplied from the power source to the photographing lens, a detecting means for detecting an abnormality in power supply based on the output of the monitoring means, and a means for starting or stopping the power supply from the power source to the photographing lens. When the detecting means detects an abnormality, a control means for stopping the power supply is provided.

[0003] Patent Document 2 describes a power supply device including a power supply circuit, a protection element that cuts off the input to the power supply circuit when the input current value to the power supply circuit reaches a first value, and releases the cut-off of the input to the power supply circuit when the input current value falls below the first value after the cut-off, and an overcurrent detection unit that detects an output current value from the power supply circuit and outputs a predetermined signal when the value reaches a second value.

[0004] Patent Document 3 describes a power supply device having a voltage generation means for generating an output voltage from an input voltage, an output connector for outputting the output voltage of the voltage generation means to the outside, a protection switch connected between the voltage generation means and the output connector, a determination means for determining whether or not the output current of the voltage generation means exceeds a threshold value, and a control means for performing control to turn off the protection switch when a current larger than the threshold value flows.

[0005] Japanese Patent Application Laid-Open No. 2002-250964, Japanese Patent Application Laid-Open No. 2005-038281, Japanese Patent Application Laid-Open No. 2017-079567

[0006] (1) An electronic device comprising: a connector that can be connected to an external device; a first current detection circuit and a second current detection circuit that detect the current flowing between a power supply and the connector; and a conversion circuit that converts an analog value into a digital value, wherein the conversion circuit receives a first voltage value based on the current value detected by the first current detection circuit and a second voltage value based on the current value detected by the second current detection circuit as input.

[0007] (2) An electronic device as described in (1), wherein the input terminal of the conversion circuit is connected to the terminal of the first current detection circuit which outputs the first voltage value and the terminal of the second current detection circuit which outputs the second voltage value.

[0008] (3) An electronic device as described in (1), wherein the first voltage value and the second voltage value are different.

[0009] (4) An electronic device as described in (3), wherein the first voltage value is lower than the second voltage value.

[0010] (5) An electronic device according to any one of (1) to (4), wherein the first voltage value is input to the conversion circuit when the current flowing between the power supply and the connector becomes a first current value greater than a current threshold.

[0011] (6) An electronic device as described in (5), wherein the second voltage value is input to the conversion circuit when the current flowing between the power supply and the connector becomes a second current value less than or equal to the current threshold.

[0012] (7) An electronic device according to any one of (1) to (6), wherein the first current detection circuit disconnects the electrical connection between the power supply and the connector when it detects a current value greater than a current threshold.

[0013] (8) An electronic device according to any one of (1) to (7), wherein the second current detection circuit includes a current-voltage conversion circuit that converts the current value flowing between the power supply and the connector into a voltage value, and an adder circuit that adds a predetermined voltage to the voltage value output from the current-voltage conversion circuit to output the second voltage value.

[0014] (9) An electronic device according to any one of (1) to (8), comprising a processor that acquires a voltage value output from the conversion circuit and performs processing based on the voltage value.

[0015] (10) An electronic device as described in (9), wherein the first current detection circuit can take a first state in which the electrical connection between the power supply and the connector is interrupted, and a second state in which the electrical connection between the power supply and the connector is not interrupted, and the processor controls the state of the first current detection circuit based on the voltage value.

[0016] (11) An electronic device as described in (10), wherein the processor controls the first current detection circuit to the second state, and controls the first current detection circuit to the first state when the voltage value obtained from the conversion circuit is less than or equal to a voltage threshold greater than the first voltage value.

[0017] (12) An electronic device as described in (11), wherein the processor sets the voltage value obtained from the conversion circuit as the voltage threshold when the first current detection circuit is controlled to the first state.

[0018] (13) Electronic device according to (11) or (12), wherein the processor controls the first current detection circuit to the second state after a predetermined time has elapsed, when the voltage value obtained from the conversion circuit is the voltage threshold and the first current detection circuit is controlled to the first state.

[0019] (14) An electronic device according to any one of (11) to (13), wherein the processor determines that current is flowing in from the connector when the voltage value obtained from the conversion circuit is less than the voltage threshold and greater than the first voltage value.

[0020] (15) An electronic device according to any one of (9) to (14), wherein the processor, when it obtains the first voltage value from the conversion circuit, determines the factors that caused the voltage value output from the conversion circuit to become the first voltage value, based on the changes in the voltage values ​​obtained from the conversion circuit up to the time the first voltage value was obtained.

[0021] (16) An electronic device according to any one of (1) to (15), wherein the external device is a lens device, and the electronic device comprises an image sensor that captures an image of a subject through the lens device.

[0022] Figure 1 is a diagram showing the schematic configuration of an electronic device 100, which is one embodiment of the technology of this disclosure. Figure 2 is a diagram showing the relationship between the current flowing between the power supply Vd and the connector 1 and the output of the conversion circuit 4. Figure 3 is a diagram illustrating the operation of the electronic device 100. Figure 4 is a diagram illustrating the operation of the electronic device 100. Figure 5 is a diagram illustrating the operation of the electronic device 100. Figure 6 is a diagram illustrating the operation of the electronic device 100. Figure 7 is a diagram illustrating the operation of the electronic device 100. Figure 8 is a diagram showing an example of the output change of the conversion circuit 4 until an overcurrent detection state is reached.

[0023] Figure 1 shows a schematic configuration of an electronic device 100, which is one embodiment of the technology of the present disclosure. The electronic device 100 is a digital camera with a detachable lens device 200, and is equipped with an image sensor 8 that captures an image of a subject through the attached lens device 200. The lens device 200 is an example of an external device.

[0024] Furthermore, the electronic device 100 includes a connector 1 that can be electrically connected to the lens device 200, a first current detection circuit 2 and a second current detection circuit 3 that detect the current flowing between the power supply Vd and the connector 1, a conversion circuit 4 that converts analog values ​​to digital values, a control unit 5 that performs various processing including the control of the first current detection circuit 2, a resistor 6, and a capacitor 7. A switch 21 included in the first current detection circuit 2 and a resistor 31 included in the second current detection circuit 3 are connected in series between the power supply Vd and the connector 1. The power supply Vd is a battery built into the electronic device 100, a battery that can be attached to or removed from the electronic device 100, or a commercial power supply, etc.

[0025] The first current detection circuit 2 is, for example, a chip-type electronic fuse and includes a power terminal T1 connected to the power supply Vd, a system output terminal T2, an abnormality detection output terminal T3, a reference potential terminal T4 connected to a reference potential Vref (which is 0V in this embodiment), and an enable terminal T5 connected to the control unit 5.

[0026] The first current detection circuit 2 includes a switch 21 with one end connected to the power supply terminal T1 and the other end connected to the system output terminal T2, a switch 22 with one end connected to the reference potential terminal T4 and the other end connected to the abnormality detection output terminal T3, and a controller 23 that performs processing to detect the current flowing between the power supply Vd and the connector 1, and on / off control of switches 21 and 22, respectively.

[0027] When switch 21 is off, the first current detection circuit 2 enters a first state in which it disconnects the electrical connection between the power supply Vd and the connector 1. When switch 21 is on, the first current detection circuit 2 enters a second state in which it does not disconnect the electrical connection between the power supply Vd and the connector 1.

[0028] The controller 23 starts up when, for example, a high-level enable signal is input to the enable terminal T5, and turns on switch 21 and off switch 22. In this state, if the current flowing between the power supply Vd and connector 1 becomes greater than the current threshold iTh, the controller 23 turns off switch 21 to prevent overcurrent from flowing to the lens device 200, and also turns on switch 22. When switch 22 is turned on, the abnormality detection output terminal T3 and the reference potential terminal T4 are connected, and a voltage of reference potential Vref (0V) is output from the abnormality detection output terminal T3 as an abnormality detection output signal. The abnormality detection output signal constitutes a first voltage value based on the current value detected by the controller 23 (a first current value greater than the current threshold iTh).

[0029] When a low-level disable signal, for example, is input to the enable terminal T5, the controller 23 turns off switches 21 and 22 and stops.

[0030] The second current detection circuit 3 includes a resistor 31 with one end connected to the system output terminal T2 and the other end connected to the connector 1, a current-voltage conversion circuit 32 that converts the current value flowing between the power supply Vd and the connector 1 into a voltage value, and an adder circuit 33 that adds a predetermined offset voltage Vofs (for example, 0.5V) to the voltage value output from the current-voltage conversion circuit 32. The offset voltage Vofs constitutes a voltage threshold.

[0031] The current-voltage conversion circuit 32 is composed of a differential amplifier. A non-inverting input terminal (+) is connected to the node connecting the resistor 31 and the system output terminal T2, and an inverting input terminal (-) is connected to the node connecting the resistor 31 and the connector 1. When the switch 21 is ON and current flows from the power supply Vd to the connector 1, the potential of the node connecting the system output terminal T2 and the resistor 31 becomes greater than the potential of the node connecting the resistor 31 and the connector 1. This potential difference is proportional to the current flowing through the resistor 31. Therefore, when the switch 21 is ON and the lens device 200 is connected to the connector 1, the output voltage of the current-voltage conversion circuit 32 is proportional to the current flowing through the resistor 31.

[0032] When switch 21 is off or the lens device 200 is not connected to connector 1, no current flows through resistor 31, and therefore the output voltage of the current-voltage conversion circuit 32 becomes 0V.

[0033] The output voltage of the current-voltage conversion circuit 32 has an offset voltage Vofs added to it. Therefore, when the switch 21 is ON and current flows from the power supply Vd to the connector 1, the summing circuit 33 outputs a voltage greater than the offset voltage Vofs (0.5V).

[0034] Furthermore, if no current is flowing between the power supply Vd and the connector 1, such as when the first current detection circuit 2 is stopped, the first current detection circuit 2 is running but switch 21 is off, or switch 21 is on but the lens device 200 is not installed, the summing circuit 33 outputs an offset voltage Vofs (0.5V).

[0035] Furthermore, when switch 21 is ON and the lens device 200 is connected to connector 1, current may flow backward from the lens device 200 towards the power supply Vd, causing current to flow in from connector 1. When current flows in from connector 1, the current value flowing between the power supply Vd and connector 1 is defined as a negative value.

[0036] When switch 21 is ON and current flows from connector 1 towards power supply Vd, the potential of the node connecting system output terminal T2 and resistor 31 becomes lower than the potential of the node connecting resistor 31 and connector 1, and the output voltage of the current-voltage conversion circuit 32 becomes a negative value less than 0V.

[0037] Therefore, when current flows in from connector 1, the output voltage of the second current detection circuit 3 will be smaller than the offset voltage Vofs. The magnitude of the offset voltage Vofs may be set so that even when the maximum possible current flows in from connector 1, the output voltage of the summing circuit 33 is greater than the reference potential Vref (0V).

[0038] Thus, when the switch 22 is in the OFF state, the output voltage of the addition circuit 33 (synonymous with the output voltage of the second current detection circuit 3) is input to the conversion circuit 4, and its voltage value constitutes a second voltage value based on the current value detected by the second current detection circuit 3 (the second current value that is less than or equal to the current threshold value iTh).

[0039] One end of the resistor 6 is connected to the output terminal of the addition circuit 33, and the other end is connected to the abnormality detection output terminal T3 of the first current detection circuit 2. The node connecting the abnormality detection output terminal T3 and the resistor 6 is connected to the input terminal of the conversion circuit 4. A capacitor 7 is connected between the wiring path connecting this node and the conversion circuit 4 and the reference potential. The digital voltage value output from the conversion circuit 4 is input to the control unit 5.

[0040] FIG. 2 is a diagram showing the relationship between the current flowing between the power supply Vd and the connector 1 and the output of the conversion circuit 4. In FIG. 2, the conversion upper limit value Vmax in the conversion circuit 4 is set to 3V, and the conversion lower limit value Vmin is set to 0V.

[0041] When the current flowing between the power supply Vd and the connector 1 is greater than 0A and less than or equal to the current threshold value iTh, the switch 22 is controlled to be OFF. Therefore, the output voltage of the addition circuit 33 (a voltage greater than the offset voltage Vofs) is input to the conversion circuit 4 and converted into a digital value.

[0042] When no current is flowing between the power supply Vd and the connector 1, the switch 22 is controlled to be OFF. Therefore, the output voltage of the addition circuit 33 (coinciding with the offset voltage Vofs) is input to the conversion circuit 4 and converted into a digital value.

[0043] When the current flowing between the power supply Vd and the connector 1 is a negative value, the switch 22 is controlled to be OFF. Therefore, the output voltage of the addition circuit 33 (a voltage less than the offset voltage Vofs) is input to the conversion circuit 4 and converted into a digital value.

[0044] Therefore, when the current flowing between the power supply Vd and the connector 1 is less than or equal to the current threshold value iTh, the output value of the conversion circuit 4 is 0V or more and 3V or less as shown in FIG. 2.

[0045] On the other hand, when the current flowing between the power supply Vd and the connector 1 is greater than the current threshold value iTh, the switch 22 is controlled to be turned on. For this reason, the potential of the input terminal of the conversion circuit 4 becomes the reference potential Vref (0V) regardless of the output of the addition circuit 33. Therefore, the output value of the conversion circuit 4 in this case becomes 0V as shown in FIG. 2.

[0046] Thus, according to the electronic device 100, depending on the magnitude of the output value of the conversion circuit 4, an overcurrent detection state in which an overcurrent exceeding the current threshold value iTh flows between the power supply Vd and the connector 1 and the protection function of the first current detection circuit 2 is activated, a reverse current state in which current flows into the connector 1, a normal state in which a current greater than 0A and less than or equal to the current threshold value iTh flows between the power supply Vd and the connector 1, and a non-powered state in which no current flows between the power supply Vd and the connector 1 can be distinguished and determined.

[0047] As shown in FIG. 2, when the current amount is large in the reverse current state, the output of the conversion circuit 4 can become 0V in the same manner as when an overcurrent exceeding the current threshold value iTh flows between the power supply Vd and the connector 1. However, even in such a case, by referring to the transition of the output before the output of the conversion circuit 4 becomes 0V, it is possible to distinguish between the overcurrent detection state and the reverse current state. As described above, if the offset voltage Vofs is set so that the output of the conversion circuit 4 does not become 0V even in the reverse current state, the overcurrent detection state and the reverse current state can be distinguished without referring to such an output transition. Also, even if the offset voltage Vofs is not set in this way, the current flowing in the reverse current state does not become very large, so in most cases, the output of the conversion circuit 4 is greater than 0V even in the reverse current state.

[0048] The control unit 5 determines which of the overcurrent detection state, reverse current state, normal state, and non-powered state it is based on the output value of the conversion circuit 4, and performs processing according to the determination result.

[0049] For example, when the control unit 5 determines that it is in the overcurrent detection state, it outputs a disable signal to stop the first current detection circuit 2 or prompts the user to perform an operation to avoid the overcurrent.

[0050] Furthermore, if the control unit 5 determines that a reverse current is present, it will output a disable signal to stop the first current detection circuit 2, or it will issue a notification prompting the lens device 200 to be repaired.

[0051] Furthermore, the control unit 5 determines that the system is in a normal state, and if the output value of the conversion circuit 4 is greater than the upper limit expected when the lens device 200 is installed, it determines that the operating load is high and performs processing to suppress heat generation.

[0052] Furthermore, if the control unit 5 determines that the circuit is not energized, it outputs a disable signal to stop the first current detection circuit 2, and after a predetermined time has elapsed, it outputs an enable signal to start the first current detection circuit 2. Details of this process will be described later.

[0053] Figures 3 to 7 are diagrams illustrating the operation of the electronic device 100.

[0054] When the control unit 5 detects an operation to turn on the power to the lens device 200 provided on the electronic device 100 while the lens device 200 is not connected to the connector 1 of the electronic device 100, it outputs an enable signal as shown in Figure 3 to start the first current detection circuit 2. When the first current detection circuit 2 is started, switch 21 turns on and switch 22 turns off. Here, since the lens device 200 is not connected to the connector 1, no current flows through the resistor 31, and the output voltage of the current-voltage conversion circuit 32 becomes 0V. Therefore, the offset voltage Vofs is input to the conversion circuit 4, which is converted to a digital value and input to the control unit 5.

[0055] When the control unit 5 is outputting an enable signal and receives an offset voltage Vofs from the conversion circuit 4, it determines that the lens device 200 is not connected to the connector 1. Then, as shown in Figure 4, the control unit 5 outputs a disable signal to stop the first current detection circuit 2. When the first current detection circuit 2 stops, the switch 21 turns off. As a result, no current flows through the resistor 31, and the output voltage of the current-voltage conversion circuit 32 remains at 0V. Consequently, the offset voltage Vofs is input to the conversion circuit 4, which is converted to a digital value and input to the control unit 5.

[0056] When the control unit 5 is outputting a disable signal and the offset voltage Vofs is input, if this condition continues for a predetermined time, it outputs an enable signal to activate the first current detection circuit 2 and return to the state shown in Figure 3. In this way, the state shown in Figure 3 and the state shown in Figure 4 are repeated alternately until the lens device 200 is connected to the connector 1.

[0057] By repeatedly switching the first current detection circuit 2 on and off, the probability of being able to turn on the switch 21 and supply power to the lens device 200 after the lens device 200 is connected to the connector 1 can be increased.

[0058] For example, if the time from startup to shutdown of the first current detection circuit 2 (the predetermined time mentioned above) is set to 100 ms, and the startup cycle of the first current detection circuit 2 is set to 1 s, then with a 90% probability, the lens device 200 will be connected to the connector 1 while the switch 21 is in the off position.

[0059] As shown in Figure 4, when the lens device 200 is connected to the connector 1 and the control unit 5 activates the first current detection circuit 2, a current i1 less than or equal to the current threshold iTh flows from the power supply Vd to the connector 1, as shown in Figure 5. Therefore, the output voltage of the current-voltage conversion circuit 32 becomes a voltage Vi1 corresponding to the current i1. The conversion circuit 4 receives a voltage value V2, which is the sum of the voltage Vi1 and the offset voltage Vofs, and this is converted to a digital value and input to the control unit 5. Since the voltage value V2 is greater than the offset voltage Vofs, the control unit 5 determines that it is in a normal state and maintains the state shown in Figure 5.

[0060] In the state shown in Figure 5, when the current flowing from the power supply Vd to the connector 1 changes to a current i2 that is greater than the current threshold iTh, the controller 23 turns off switch 21 and turns on switch 22, as shown in Figure 6. As a result, a reference potential Vref (0V) voltage is input to the conversion circuit 4, which is converted to a digital value and input to the control unit 5. The control unit 5 determines that an overcurrent detection state has been detected because the input voltage value is 0V, and prompts the user to take action to avoid the overcurrent or outputs a disable signal to stop the first current detection circuit 2.

[0061] Figure 7 is a diagram illustrating the operation when current flows in from connector 1. Figure 7 shows an example where current i3 flows from connector 1 to power supply Vd, as shown in Figure 5. In this example, the output voltage of the current-voltage conversion circuit 32 becomes a negative voltage Vi3 corresponding to the current i3. The conversion circuit 4 receives a voltage value V3, which is the sum of the negative voltage Vi3 and the offset voltage Vofs, and this is converted into a digital value and input to the control unit 5. Since the voltage value V3 is smaller than the offset voltage Vofs, the control unit 5 determines that a reverse current is occurring and stops the first current detection circuit 2. This results in the state shown in Figure 4.

[0062] The offset voltage Vofs may be a fixed value determined at the time of manufacture, but the electronic device 100 may be configured to perform periodic calibration. For example, the control unit 5 performs calibration at a predetermined timing, such as when the power to the electronic device 100 is turned on.

[0063] In this calibration process, first, the control unit 5 acquires a voltage value from the conversion circuit 4 with the first current detection circuit 2 stopped. When the first current detection circuit 2 is stopped, as shown in Figure 4, the voltage value of the power supply connected to the adder circuit 33 is input to the control unit 5. The control unit 5 sets the voltage value acquired at this time as the voltage threshold. Then, it compares the voltage value acquired from the conversion circuit 4 with this voltage threshold, and if this voltage value matches the voltage threshold, it determines that it is in a non-conducting state. The control unit 5 also determines that it is in a normal state if this voltage value is greater than the voltage threshold. The control unit 5 also determines that it is in a reverse current state if this voltage value is less than or equal to the voltage threshold. The control unit 5 also determines that it is in an overcurrent detection state if this voltage value matches the reference potential Vref.

[0064] By performing this calibration process, current detection errors and voltage summing errors in the second current detection circuit 3 can be corrected, including environmental changes such as temperature, enabling highly accurate determination of the state of the electronic device 100.

[0065] If the control unit 5 determines that an overcurrent detection state is in effect, it may determine the cause of the voltage value output from the conversion circuit 4 becoming the reference potential Vref (in other words, the cause of the overcurrent detection state) based on the changes in the voltage value obtained from the conversion circuit 4 until the reference potential Vref is obtained from the conversion circuit 4.

[0066] Figure 8 shows an example of the output change of the conversion circuit 4 from the normal state to the overcurrent detection state. Cases in which an overcurrent exceeding the current threshold iTh flows between the power supply Vd and the connector 1 include a first pattern in which the current gradually increases and exceeds the current threshold iTh, as shown by the solid line graph in Figure 8, and a second pattern in which the current increases rapidly and exceeds the current threshold iTh, as shown by the dashed line graph in Figure 8. The first pattern is assumed to occur, for example, when the operating load of the lens device 200 becomes large and an overcurrent flows. The second pattern is assumed to occur, for example, when the connector 1 is short-circuited.

[0067] The control unit 5 sets a judgment threshold VTh that is smaller than the conversion upper limit Vmax. The control unit 5 determines that an overcurrent is detected at the first timing when the output of the conversion circuit 4 becomes the reference potential Vref. Then, the control unit 5 obtains a second timing before this first timing when the output of the conversion circuit 4 exceeds the judgment threshold VTh, and obtains the time between the first timing and the second timing.

[0068] As shown in Figure 8, this time is time t1 in the first pattern and time t2 in the second pattern. The control unit 5 determines that it is the second pattern if this time is less than or equal to the time threshold, and determines that it is the first pattern if this time is longer than the time threshold. In this way, the control unit 5 can determine the cause of the overcurrent. The control unit 5 may also notify the user of the determined cause.

[0069] In this embodiment, each process performed by the control unit 5 is executed on any computer. Furthermore, any computer may execute these processes using a processor as hardware, a program as software, or a combination thereof. In that case, the processor is configured to cooperate with the program to execute the various processes in this embodiment, and can function as each unit or means in this embodiment. Also, the execution order of the processes by the processor is not limited to the order described and may be changed as appropriate. Any computer may be a general-purpose computer, a computer designed for a specific application, a workstation, or any other system capable of executing each process.

[0070] A processor may consist of one or more hardware components, and the type of hardware is not limited. For example, a processor may consist of programmable logic devices such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), FPGA (Field Programmable Gate Array), dedicated circuits for executing specific processes such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a processor, these multiple hardware components may reside in physically separate devices or in the same device. Furthermore, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. The hardware is composed of an electrical circuit (circuitry) or the like, which is a combination of circuit elements such as semiconductor elements.

[0071] Furthermore, the program may be firmware or software such as microcode. Alternatively, the program may be, for example, a group of program modules, each function of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage). The program may be divided and stored on multiple non-temporary computer-readable media located on physically separate devices. Program code or code segments may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. Program code or code segments may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents.

[0072] In the above description, the electronic device 100 is assumed to be a digital camera, but it is not limited to this. The technology of this disclosure is applicable to any electronic device that is electrically connected to an external device by connector 1 and can supply power to this external device.

[0073] Although various embodiments have been described above, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined arbitrarily without departing from the spirit of the invention. For example, as variations of external equipment connected to the electronic device 100, any of the following A to E may be used: A: External LCD (liquid crystal display) monitor B: External recording device C: Audio unit (including microphone, control unit for video synchronization, etc.) D: Focus unit (including distance measuring device, control unit for focus control, etc.) E: External controllers for iris, focus, zoom, etc.

[0074] This application is based on a Japanese patent application (Patent Application No. 2024-192213) filed on October 31, 2024, the contents of which are incorporated herein by reference.

[0075] 1 Connector T1 Power terminals Vi1, Vi3 Voltage t1, t2 Time 2 First current detection circuit T2 System output terminals V2, V3 Voltage value 3 Second current detection circuit T3 Anomaly detection output terminal 4 Conversion circuit T4 Reference potential terminal 5 Control unit T5 Enable terminal 6, 31 Resistors 7 Capacitors 8 Image sensor 21, 22 Switches 23 Controller 32 Current-voltage conversion circuit 33 Adding circuit 100 Electronic equipment 200 Lens device

Claims

1. An electronic device comprising: a connector connectable to an external device; a first current detection circuit and a second current detection circuit for detecting the current flowing between a power supply and the connector; and a conversion circuit for converting an analog value into a digital value, wherein the conversion circuit receives a first voltage value based on the current value detected by the first current detection circuit and a second voltage value based on the current value detected by the second current detection circuit as input.

2. An electronic device according to claim 1, wherein the input terminal of the conversion circuit is connected to the terminal of a first current detection circuit that outputs the first voltage value and to the terminal of a second current detection circuit that outputs the second voltage value.

3. An electronic device according to claim 1, wherein the first voltage value and the second voltage value are different.

4. The electronic device according to claim 3, wherein the first voltage value is lower than the second voltage value.

5. An electronic device according to claim 1, wherein the first voltage value is input to the conversion circuit when the current flowing between the power supply and the connector becomes a first current value greater than a current threshold.

6. An electronic device according to claim 5, wherein the second voltage value is input to the conversion circuit when the current flowing between the power supply and the connector becomes a second current value less than or equal to the current threshold.

7. An electronic device according to claim 1, wherein the first current detection circuit disconnects the electrical connection between the power supply and the connector when it detects a current value greater than a current threshold.

8. An electronic device according to claim 1, wherein the second current detection circuit includes a current-voltage conversion circuit that converts a current value flowing between the power supply and the connector into a voltage value, and an adder circuit that adds a predetermined voltage to the voltage value output from the current-voltage conversion circuit to output the second voltage value.

9. An electronic device according to claim 1, comprising a processor that acquires a voltage value output from the conversion circuit and performs processing based on the voltage value.

10. Electronic device according to claim 9, wherein the first current detection circuit can take a first state in which the electrical connection between the power supply and the connector is interrupted, and a second state in which the electrical connection between the power supply and the connector is not interrupted, and the processor controls the state of the first current detection circuit based on the voltage value.

11. Electronic device according to claim 10, wherein the processor controls the first current detection circuit to the second state, and controls the first current detection circuit to the first state when the voltage value obtained from the conversion circuit is less than or equal to a voltage threshold greater than the first voltage value.

12. Electronic device according to claim 11, wherein the processor sets the voltage value obtained from the conversion circuit as the voltage threshold when the first current detection circuit is controlled to the first state.

13. Electronic device according to claim 11, wherein the processor controls the first current detection circuit to a second state after a predetermined time has elapsed when the voltage value obtained from the conversion circuit is the voltage threshold and the first current detection circuit is controlled to a first state.

14. Electronic device according to claim 11, wherein the processor determines that current is flowing in from the connector when the voltage value obtained from the conversion circuit is less than the voltage threshold and greater than the first voltage value.

15. Electronic device according to claim 9, wherein the processor, when it obtains the first voltage value from the conversion circuit, determines the factors that caused the voltage value output from the conversion circuit to become the first voltage value, based on the changes in the voltage values ​​obtained from the conversion circuit up to the time the first voltage value was obtained.

16. An electronic device according to any one of claims 1 to 15, wherein the external device is a lens device, and the electronic device comprises an image sensor that captures an image of a subject through the lens device.

Images