JP2008217607A - Power unit and equipment having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power unit in which a power supply part for power saving can be optimally designed to attain the power saving more. <P>SOLUTION: A power unit 2 has: a first power supply part 4 for generating a first voltage to be supplied for a first circuit 9 in a first operating state; a second power supply part 5 for generating a second voltage equal to or lower than the first voltage to be supplied for the first circuit in a second operating state that it operates with lower current consumption than the first operating state; and control units 6 and 3a for transmitting instruction signals for instructing switch between a first power supply state for operating the first power supply part and a second power supply state for operating the second power supply part and switch of the first circuit to the first operating state. The control units switch the second power supply state to the first power supply state in accordance with reception of a specific signal from the first circuit in the second operating state and, after the switch is completed, transmit the instruction signals to the first circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply device mounted on a device, and more particularly to a power supply device that selectively outputs different voltages from a plurality of power supply units.

  Optical devices such as video cameras and digital still cameras include an electric circuit system including a control element such as a CPU and a large number of electric elements. The control element has a normal operation state (also referred to as an active state) and a power saving operation state (also referred to as a low power consumption state or a sleep state) corresponding to the state of the optical device (electric circuit system). When the optical device in the normal operation state is not operated at all for a predetermined time, the power consumption is reduced by switching to the power saving operation state.

  In order to further reduce power consumption, it is also necessary to suppress power consumption of the power supply device itself that supplies a voltage to the electric circuit system. For this reason, Patent Documents 1 and 2 disclose a power supply device that includes a plurality of power supply units having different output voltages and selects an optimal power supply unit according to the state of a control element or the like.

Examples of a method for switching the power supply unit of the power supply device include the following methods. That is, when a so-called WAKE-UP signal is input to the electric circuit system from an external circuit or from within the electric circuit system, the WAKE-UP signal is first input to the control element. The control element is switched from the power saving operation state to the normal operation state by the WAKE-UP signal, and the power supply unit of the power supply device is switched from the power saving power supply unit to the normal operation power supply unit.
JP-A-11-65683 JP 2006-18409 A

  However, when the above method is used, when the WAKE-UP signal is input from the external circuit, the control element first enters the normal operation state. For this reason, as a drive capability of the power saving power supply unit, it is necessary to secure a drive capability necessary for the operation of the control element in the normal operation state at least.

  In addition, some recent control elements do not suddenly enter the normal operation mode but pass through a WAKE-UP state that consumes less power than the normal operation state. However, even in this case, more power is required than in the power saving operation state. Therefore, it is necessary to design the power saving power supply unit in consideration of a power consumption state that is higher than the power consumption in the power saving operation state of the electric circuit system. For this reason, an optimal circuit design cannot be performed for the power saving operation state.

  The present invention is a power supply device that supplies a voltage to an electric circuit system having a normal operation state and a power saving operation state, and the power saving power supply unit is optimal for power consumption in the power saving operation state of the electric circuit system It is possible to design a power supply device that can be designed to be more power-saving.

A power supply device according to one aspect of the present invention supplies a voltage to a first circuit having a first operating state and a second operating state that operates with a current consumption lower than that of the first operating state. A power supply apparatus, which supplies a first power supply unit that generates a first voltage to be supplied to a first circuit in a first operation state, and a first circuit in a second operation state Therefore, a second power supply unit that generates a second voltage that is equal to or lower than the first voltage, a first power supply state that operates the first power supply unit, and a second power supply unit are operated. And a control unit that transmits an instruction signal instructing switching to the first power state and switching to the first operation state for the first circuit. The control unit switches from the second power supply state to the first power supply state in response to reception of the specific signal from the first circuit in the second operation state, and after the switching is completed, An instruction signal is transmitted to one circuit.

  Note that a device including the power supply device and the first circuit, and a device including the power supply device and the first circuit and detachably connected to other devices also include other aspects of the present invention. Constitute.

  According to the present invention, when switching the first circuit from the second operation state to the first operation state with higher current consumption, the control unit first sets the power supply device to the first operation state corresponding to the first operation state. To the power supply state (first power supply unit). Thereafter, the first circuit is switched to the first operating state. Therefore, the drive capability of the second power supply unit can be set according to the low power consumption corresponding to the first operation state in the first circuit, and further power saving can be realized as compared with the conventional case. it can.

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

  FIG. 1 shows an interchangeable lens (optical device) for a single-lens reflex camera equipped with a power supply circuit system (power supply device) that is Embodiment 1 of the present invention, and a single-lens reflex camera to which the interchangeable lens is detachably attached (connected). 2 shows a circuit configuration of a camera (another optical device).

  In FIG. 1, reference numeral 1 denotes an interchangeable lens, which has an imaging optical system (not shown). The interchangeable lens 1 is provided with a power supply circuit system 2 and a circuit system (first circuit) 9 for controlling the operation of the imaging optical system (autofocus operation, image stabilization operation, etc.). Further, in the circuit system 9, there are a CPU 10 which is a control element for controlling the entire operation of the interchangeable lens 1, and an operation of an electric element such as an actuator provided in the interchangeable lens 1 in accordance with a signal from the CPU 10. And a peripheral circuit 11 for controlling the above.

  The power supply circuit system 2 is provided with a power supply circuit (power supply unit) 3 and a logic circuit 6. The power supply circuit 3 includes a first power supply circuit 4 for an active state (ACTIVE) that generates a first voltage. The power supply circuit 3 operates with less current consumption (power consumption) than the first power supply circuit 4 and generates a second voltage lower than the first voltage. The second power supply for the sleep state (SLEEP) Power supply circuit 5. The power supply circuit 3 outputs (supplies) a voltage from one of the first and second power supply circuits 4 and 5 to the circuit system 9 in response to a signal from the logic circuit 6.

  The circuit system 9 including the CPU 10 switches between an active state which is a normal operation state and a sleep state which is a power saving operation state with a lower current consumption (power consumption) than the active state. The active state (first operation state) is a state in which the operation of the imaging optical system (autofocus operation, image stabilization operation, etc.) is executed. In the active state, when no operation or operation is performed on the lens 1 for a certain time, the circuit system 9 switches to the sleep state (second operation state). In the sleep state, when any operation is performed on the lens 1, the circuit system 9 is switched to the active state.

  The circuit system 9 operates in response to the supply of the first voltage described above in the active state, and operates in response to the supply of the second voltage in the sleep state.

  Here, the first voltage is, for example, 3V, and the second voltage is, for example, 1.7V. Furthermore, in the CPU 10, the current (consumption current) required in the sleep state is 1 to 10 μA, for example, whereas the current required in the active state is 50 mA, for example. Accordingly, the maximum output current of the first power supply circuit 4 is set to be larger than the maximum output current of the second power supply circuit 5.

  The logic circuit 6 includes a communication determination unit 7 and a communication signal processing unit 8. The communication determination unit 7 determines the operation state of the circuit system 9 and the external circuit through communication with the circuit system 9 and communication with an external circuit described later. Also, the type of signal received from the circuit system 9 and the external circuit (for example, first and second WAKE-UP signals described later) is also determined.

  Furthermore, the logic circuit 6 outputs a switching signal for instructing the power supply circuit 3 to switch the power supply state according to the determination result in the communication determination unit 7. The power supply circuit 3 includes a switching operation unit 3a. In response to the switching signal, the switching operation unit 3a operates the first power supply circuit 4 to supply the first voltage to the circuit system 9 (hereinafter referred to as the first power supply state) and the second The power supply circuit 5 is operated to switch to a state in which the second voltage is supplied to the circuit system 9 (hereinafter referred to as a second power supply state).

  In addition, the control part of the power supply circuit system 2 is comprised by the switching operation part 3a among the logic circuit 6 and the power supply circuit 3. FIG.

  The communication signal processing unit 8 processes a communication signal from the camera 12 having an external circuit (second circuit).

  The power supply circuit system of the present embodiment is implemented in a form mounted on a hybrid integrated circuit (hybrid IC). However, it may have an IC configuration other than the hybrid IC or a configuration other than the IC configuration.

  In addition, the interchangeable lens 1 includes a WAKE-UP signal generation unit 16 including an operation member such as a changeover switch (hereinafter referred to as an A / M switch) that selects autofocus and manual focus.

  The camera 12 has a constant voltage circuit 15. The constant voltage circuit 15 is equipped with a power source 14 such as a lithium battery or a secondary battery, and generates a constant voltage (for example, 5 V) by the output from the power source 14 to supply the power source voltage to the inside of the camera 12 and the interchangeable lens 1. Supply.

  In addition, the camera 12 includes a CPU 13 that controls driving of the camera 12 and communicates with the interchangeable lens 1.

  The communication line (1) ((1) is shown as a circle 1 in the figure. Other communication lines are the same), the communication clock line, the data line for transmitting data from the lens 1 to the camera 12, and the camera 12 And a data line for transmitting data to the lens 1. The communication line (2) includes a communication clock line, a data line for transmitting data from the circuit system 9 to the power supply circuit system 2, and a data line for transmitting data from the power supply circuit system 2 to the circuit system 9. The

  The communication line (1) is a power level logic from the camera 12, and the communication line (2) is a voltage level logic output from the power circuit 3. The communication signal processing unit 8 performs level conversion according to the difference in communication level.

  Further, the signals of the communication line (1) and the communication line (2) are synchronized in the normal state communication.

  The above is the outline of the circuit configuration of the interchangeable lens 1 equipped with the power supply circuit system 2 and the camera 12 connected thereto.

  Next, when the circuit system 9 (that is, the entire circuit of the lens 1) is in the sleep state and the power supply circuit 3 is in the second power supply state, the power supply for shifting the circuit system 9 from the sleep state to the active state A state switching method will be described. Here, the timing charts of FIGS. 1 and 2 and the flowchart of FIG. 5 are used.

  When the A / M switch provided in the WAKE-UP signal generator 16 of the circuit system 9 is switched, the first WAKE-UP signal (specific signal) is output from the WAKE-UP signal generator 16 to the power supply circuit system 2. (Transmission) is performed (t1 in FIG. 2 and step 101 in FIG. 5).

  When the communication determination unit 7 determines that the first WAKE-UP signal has been input (received), the power supply circuit system 2 (control unit) changes the first power supply from the second power supply state of the power supply circuit 3 accordingly. Switching to the state is started (t1, step 102).

  Here, the voltage output from the power supply circuit 3 gradually increases during the switching from the second power supply state to the first power supply state. For this reason, it takes a certain amount of time for the switching to the first power supply state to be completed, that is, to stabilize at the first voltage level corresponding to the first power supply state (this will be described in an embodiment described later). 5 shown in FIG.

  Accordingly, the power supply circuit system 2 has an internal delay time (predetermined time) that corresponds to the time until switching from the second power supply state to the first power supply state is completed in step 102 or that allows for a margin. Start counting by the timer.

  Next, when it is determined in step 103 that the delay time has elapsed, the communication signal processing unit 8 uses the communication line (1) to send the second WAKE-UP signal to the camera 12 (second circuit). A signal requesting output (request signal) is output (transmitted) (t2, step 104). That is, transmission request communication of the second WAKE-UP signal is performed.

  When the CPU 13 in the camera 12 receives the request signal for the second WAKE-UP signal, it immediately outputs the second WAKE-UP signal to the power supply circuit system 2 using the communication line (1) ( Send) (t3, step 105). Specifically, as shown in FIG. 2, the falling edge of the signal on the communication line (1) corresponds to the first WAKE-UP signal.

  In the power supply circuit system 2, when the communication determination unit 7 determines that the second WAKE-UP signal has been input, the communication signal processing unit 8 performs level conversion on the input second WAKE-UP signal. 3 WAKE-UP signal (command signal) is generated. Then, the third WAKE-UP signal is output to the CPU 10 of the circuit system 9 through the communication line (2) (step 106). Specifically, as shown in FIG. 2, the first falling edge of the signal on the communication line (2) corresponds to the third WAKE-UP signal.

  The CPU 10 shifts from the sleep state to the active state in response to the input (reception) of the third WAKE-UP signal, and then drives the peripheral circuit 11 to move the entire circuit system 9 from the sleep state to the active state. (Step 107).

  By executing the above sequence, the power supply circuit 3 is switched from the second power supply state to the second power supply state before the circuit system 9 is switched from the sleep state to the active state according to the first WAKE-UP signal output from the circuit system 9. The power state can be switched to 1. As a result, the drive capability of the second power supply circuit 5 can be designed taking into consideration only the power required for the sleep state of the circuit system 9, and the second power supply circuit 5 can be designed to save more power. Is possible.

  Even in a sequence other than the sequence described in the first embodiment, the power supply circuit 3 can be switched from the second power supply state to the first power supply state before the circuit system 9 is switched from the sleep state to the active state. This will be described with reference to the flowchart of FIG.

  When the A / M switch provided in the WAKE-UP signal generation unit 16 of the circuit system 9 is switched, the first WAKE-UP signal is output (transmitted) from the WAKE-UP signal generation unit 16 to the power supply circuit system 2. (Step 201).

  When the communication determination unit 7 determines that the first WAKE-UP signal has been input (received), the power supply circuit system 2 starts switching the power supply circuit 3 from the second power supply state to the first power supply state. (Step 202). Further, the power supply circuit system 2 starts counting a delay time (predetermined time) corresponding to the time required for switching from the second power supply state to the first power supply state by the internal timer. Further, in parallel (simultaneously), the communication signal processing unit 8 outputs (transmits) a request signal for the second WAKE-UP signal to the camera 12 using the communication line (1).

  When receiving the request signal, the CPU 13 in the camera 12 outputs (transmits) the second WAKE-UP signal to the communication signal processing unit 8 using the communication line (1) (step 203).

  If it is determined in step 204 that the delay time has elapsed, the process proceeds to step 205. In the power supply circuit system 2, the communication signal processing unit 8 converts the level of the input second WAKE-UP signal to generate a third WAKE-UP signal, and the CPU 10 of the circuit system 9 through the communication line (2). (Step 205).

  The CPU 10 shifts from the sleep state to the active state in response to the input (reception) of the third WAKE-UP signal, and then drives the peripheral circuit 11 to move the entire circuit system 9 from the sleep state to the active state. (Step 206).

  In the first and second embodiments described above, the third WAKE-UP signal is output in accordance with the determination of the delay time using a timer. However, in order to communicate with the circuit system 9 as the third WAKE-UP signal. In the case of using this clock signal, the following method can be adopted.

  That is, as shown in FIG. 11, the clock signal is masked by the number of clocks (number of pulses) corresponding to the time t1 to t2 required for switching the power supply circuit 3 from the second power supply state to the first power supply state. . As a result, the CPU 10 of the circuit system 9 recognizes the first falling edge of the clock signal whose mask has been released as the second WAKE-UP signal.

  Therefore, also in this embodiment, the third WAKE-UP signal is input to the CPU 10 of the circuit system 9 after the switching of the power supply circuit 3 from the second power supply state to the first power supply state is completed. The same effects as in the first and second embodiments can be obtained.

  In the first to third embodiments, the power supply circuit system 2 performs transmission request communication of the second WAKE-UP signal to the camera 12, receives the second WAKE-UP signal from the camera 12, and receives the third WAKE-UP signal. The sequence for transmitting the UP signal to the circuit system 9 has been described.

  However, the sequence shown in the flowchart of FIG. 9 may be adopted. In the present embodiment, the second WAKE-UP signal corresponds to an instruction signal transmitted from the power supply circuit system 2 to the circuit system 9.

When the power supply circuit system 2 determines that the communication determination unit 7 has received the first WAKE-UP signal from the WAKE-UP signal generation unit 16, the first power supply state of the power supply circuit 3 is changed from the second power supply state to the first Switching to the power state is started (step 502). The power supply circuit system 2 starts counting by the internal timer of a delay time (predetermined time) corresponding to the time until the switching from the second power supply state to the first power supply state is completed. The system 2 determines whether or not a delay time has elapsed until the switching of the power supply circuit 3 from the second power supply state to the first power supply state is completed (step 503). If it is determined that the delay time has elapsed, the power supply circuit system 2 itself outputs a second WAKE-UP signal as an instruction signal to the CPU 10 of the circuit system 9 (step 504). Thereby, CPU10 switches to an active state (step 505).

  The CPU 10 that has been switched to the active state communicates to the camera 12 that the switch has been switched to the active state using the communication lines (2) and (1) (step 506).

  Also in this case, the second WAKE-UP signal as a command signal is input to the CPU 10 of the circuit system 9 after the switching of the power supply circuit 3 from the second power supply state to the first power supply state is completed. The same effects as in Examples 1 to 3 can be obtained.

  In the first to fourth embodiments described above, the voltage output from the second power supply circuit 5 is the second voltage lower than the first voltage output from the first power supply circuit 4. The second voltage output from 5 may be equal to the first voltage output from the first power supply circuit. Even in this case, the same effects as those of the first to fourth embodiments can be obtained.

  FIG. 3 shows an interchangeable lens (optical device) for a single-lens reflex camera equipped with a power circuit system (power supply device) that is Embodiment 6 of the present invention, and a single-lens reflex camera (others) to which the interchangeable lens is detachably mounted. 2 shows a circuit configuration of the optical apparatus. In FIG. 3, components common to the circuit configuration described in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and are not described.

  In the power supply circuit system 2 of the present embodiment, an output voltage detection unit (voltage detection unit) 17 that detects a voltage output from the power supply circuit 3 is provided.

  Next, when the circuit system 9 (that is, the entire circuit of the lens 1) is in the sleep state and the power supply circuit 3 is in the second power supply state, the power supply for shifting the circuit system 9 from the sleep state to the active state A state switching method will be described. Here, the timing charts of FIGS. 3 and 4 and the flowchart of FIG. 7 are used.

  When the A / M switch provided in the WAKE-UP signal generator 16 of the circuit system 9 is switched, the first WAKE-UP signal (specific signal) is output from the WAKE-UP signal generator 16 to the power supply circuit system 2. (Transmission) is performed (t1 in FIG. 2 and step 301 in FIG. 5).

  When the communication determination unit 7 determines that the first WAKE-UP signal has been input (received), the power supply circuit system 2 (control unit) changes the first power supply from the second power supply state of the power supply circuit 3 accordingly. Switching to the state is started (t1, step 302).

  Next, as the power supply circuit system 2 switches from the second power supply state to the first power supply state, the output voltage from the power supply circuit 3 is changed from the second voltage to the first voltage through the output voltage detector 17. It is determined whether or not there has been a change (step 303).

  Here, as shown in FIG. 4, the voltage output from the power supply circuit 3 gradually increases during the switching from the second power supply state to the first power supply state. For this reason, it takes a certain amount of time to complete the switching to the first power supply state, that is, to stabilize the first voltage level corresponding to the first power supply state. Therefore, the power supply circuit system 2 determines whether or not the output voltage from the power supply circuit 3 is stabilized at the first voltage level through the output voltage detector 17. When the output voltage from the power supply circuit 3 reaches the first voltage, the output voltage detection unit 17 outputs an output detection signal, and the power supply circuit system 2 receives the output detection signal and outputs the output voltage from the power supply circuit 3. Can be determined to have reached the first voltage.

  When the power supply circuit system 2 determines that the output voltage from the power supply circuit 3 has reached the first voltage, the communication signal processing unit 8 sends a communication line (1) to the camera 12 (second circuit). A request signal for the second WAKE-UP signal is output (transmitted) (t2 ′, step 304).

  When receiving the request signal, the CPU 13 in the camera 12 immediately outputs (transmits) the second WAKE-UP signal to the power supply system 2 using the communication line (1). (T3, Step 305).

  In the power supply circuit system 2, the communication signal processing unit 8 converts the level of the input second WAKE-UP signal to generate a third WAKE-UP signal (command signal), and the circuit through the communication line (2). The data is output to the CPU 10 of the system 9 (step 306).

  When the communication determination unit 7 determines that the third WAKE-UP signal has been input (received), the CPU 10 shifts from the sleep state to the active state accordingly. Thereafter, the peripheral circuit 11 is driven to switch the entire circuit system 9 from the sleep state to the active state (step 307).

  By executing the above sequence, the power supply circuit 3 is switched from the second power supply state to the second power supply state before the circuit system 9 is switched from the sleep state to the active state according to the first WAKE-UP signal output from the circuit system 9. The power state can be switched to 1. As a result, the drive capability of the second power supply circuit 5 can be designed taking into consideration only the power required for the sleep state of the circuit system 9, and the second power supply circuit 5 can be designed to save more power. Is possible.

  Even in a sequence other than the sequence described in the sixth embodiment, the power supply circuit 3 can be switched from the second power supply state to the first power supply state before the circuit system 9 is switched from the sleep state to the active state. This will be described with reference to the flowchart of FIG.

  When the A / M switch provided in the WAKE-UP signal generation unit 16 of the circuit system 9 is switched, the first WAKE-UP signal is output (transmitted) from the WAKE-UP signal generation unit 16 to the power supply circuit system 2. (Step 401).

  When the communication determination unit 7 determines that the first WAKE-UP signal has been input (received), the power supply circuit system 2 switches the power supply circuit 3 from the second power supply state to the first power supply state accordingly. Is started (step 402). The power supply circuit system 2 starts counting the delay time (predetermined time) corresponding to the time required for switching from the second power supply state to the first power supply state by the internal timer. Further, in parallel (simultaneously), the communication signal processing unit 8 outputs (transmits) a request signal for the second WAKE-UP signal to the camera 12 using the communication line (1).

  Upon receiving the request signal, the CPU 13 in the camera 12 immediately outputs (transmits) the second WAKE-UP signal to the power supply circuit system 2 using the communication line (1) (step 403).

  If it is determined in step 204 that the delay time has elapsed, the process proceeds to step 205. In the power supply circuit system 2, the communication signal processing unit 8 converts the level of the input second WAKE-UP signal to generate a third WAKE-UP signal, and the CPU 10 of the circuit system 9 through the communication line (2). (Step 405).

  The CPU 10 shifts from the sleep state to the active state in response to the input (reception) of the third WAKE-UP signal, and then drives the peripheral circuit 11 to move the entire circuit system 9 from the sleep state to the active state. (Step 406).

  In the sixth and seventh embodiments, the power supply circuit system 2 performs transmission request communication of the second WAKE-UP signal to the camera 12, receives the second WAKE-UP signal from the camera 12, and receives the third WAKE-UP signal. The sequence for transmitting the UP signal to the circuit system 9 has been described.

  However, the sequence shown in the flowchart of FIG. 10 may be adopted. In the present embodiment, the second WAKE-UP signal corresponds to an instruction signal transmitted from the power supply circuit system 2 to the circuit system 9.

When the power supply circuit system 2 determines that the communication determination unit 7 has received the first WAKE-UP signal from the WAKE-UP signal generation unit 16, the first power supply state of the power supply circuit 3 is changed from the second power supply state to the first Switching to the power state is started (step 602). The power supply circuit system 2 starts counting by the internal timer of a delay time (predetermined time) corresponding to the time until the switching from the second power supply state to the first power supply state is completed. The system 2 determines whether or not a delay time has elapsed until the switching of the power supply circuit 3 from the second power supply state to the first power supply state is completed (step 603). If it is determined that the delay time has elapsed, the power supply circuit system 2 itself outputs a second WAKE-UP signal as an instruction signal to the CPU 10 of the circuit system 9 (step 604). Thereby, CPU10 switches to an active state (step 605).

  The CPU 10 that has been switched to the active state communicates to the camera 12 that the switch has been switched to the active state using the communication lines (2) and (1) (step 606).

  Also in this case, the second WAKE-UP signal as a command signal is input to the CPU 10 of the circuit system 9 after the switching of the power supply circuit 3 from the second power supply state to the first power supply state is completed. The same effects as in Examples 6 and 7 can be obtained. The preferred embodiments of the present invention have been described above. However, the embodiments of the present invention are not limited to these, and various modifications and changes can be made. The present invention also applies to a device that does not have its own power supply, such as a car navigation system, ETC, or PC peripheral device (hard disk), but is connected to another device having a power supply and operates by receiving a supply voltage. Applicable.

1 is a block diagram illustrating a circuit configuration of an interchangeable lens on which a power supply circuit system that is Embodiment 1 of the present invention is mounted and a camera to which the interchangeable lens is mounted. 4 is a timing chart at the time of power supply switching in the first embodiment. FIG. 6 is a block diagram illustrating a circuit configuration of an interchangeable lens equipped with a power supply circuit system that is Embodiment 5 of the present invention and a camera to which the interchangeable lens is mounted. 10 is a timing chart at the time of power supply switching in the fifth embodiment. The flowchart which shows the operation | movement at the time of the power supply switching in Example 1 of this invention. The flowchart which shows the operation | movement at the time of the power supply switching in Example 2 of this invention. The flowchart which shows the operation | movement at the time of the power supply switching in Example 5 of this invention. The flowchart which shows the operation | movement at the time of the power supply switching in Example 6 of this invention. The flowchart which shows the operation | movement at the time of the power supply switching in Example 4 of this invention. The flowchart which shows the operation | movement at the time of the power supply switching in Example 7 of this invention. 10 is a timing chart at the time of power supply switching in the third embodiment.

Explanation of symbols

1 Interchangeable lens 2 Power supply circuit system
3 Power supply circuit 4 First power supply circuit (for ACTIVE)
5 Second power supply circuit (for SLEEP)
6 Logic Circuit 7 Communication Determination Unit 8 Communication Signal Processing Unit 9 Circuit System 10 CPU in Lens
12 Camera 13 CPU in the camera
14 Power Supply in Camera 15 Constant Voltage Circuit 16 WAKE-UP Signal Generation Unit 17 Output Voltage Detection Unit

Claims (10)

A power supply device for supplying a voltage to a first circuit having a first operation state and a second operation state that operates with a current consumption lower than that of the first operation state,
A first power supply section for generating a first voltage to be supplied to the first circuit in the first operating state;
A second power supply for generating a second voltage equal to or lower than the first voltage for supplying the first circuit in the second operating state;
Switching between a first power supply state for operating the first power supply unit and a second power supply state for operating the second power supply unit, and switching to the first operation state for the first circuit A control unit that transmits an instruction signal to instruct,
The control unit switches from the second power supply state to the first power supply state in response to receiving a specific signal from the first circuit in the second operation state, and the switching is completed. And then transmitting the instruction signal to the first circuit. The control unit is configured to transmit a transmission request communication to a second circuit according to reception of the specific signal, and to the first circuit according to reception of a signal corresponding to the transmission request communication from the second circuit. Transmitting the instruction signal,
The control unit performs switching from the second power supply state to the first power supply state in response to reception of the specific signal, and after the switching is completed, the transmission request communication to the second circuit and The power supply apparatus according to claim 1, wherein the instruction signal is transmitted to the first circuit. The control unit is configured to transmit a transmission request communication to a second circuit according to reception of the specific signal, and to the first circuit according to reception of a signal corresponding to the transmission request communication from the second circuit. Transmitting the instruction signal,
The control unit performs switching from the second power supply state to the first power supply state and the transmission request communication to the second circuit in response to reception of the specific signal, and after the switching is completed The power supply apparatus according to claim 1, wherein the instruction signal is transmitted to the first circuit.   The control unit transmits the instruction signal to the first circuit in response to a lapse of time until the switching from the second power state to the first power state is completed. The power supply device according to any one of claims 1 to 3. The control unit uses a clock signal for performing communication with the first circuit as the instruction signal,
The control unit masks the clock signal and transmits it to the first circuit until switching from the second power state to the first power state is completed. Item 5. The power supply device according to any one of Items 1 to 4. The second voltage is lower than the first voltage;
A voltage detection unit for detecting a voltage supplied from the first and second power supply units to the first circuit;
In response to the detection of the first voltage by the voltage detection unit by switching from the second power supply state to the first power supply state, the control unit outputs the instruction signal to the first circuit. Transmission is performed, The power supply device as described in any one of Claim 1 to 5 characterized by the above-mentioned.   The power supply apparatus according to claim 1, wherein a maximum output current of the first power supply circuit is larger than a maximum output current of the second power supply unit.   The power supply device according to any one of claims 1 to 7, wherein the power supply device is mounted on an integrated circuit.   An apparatus comprising the power supply device according to claim 1 and the first circuit. A device comprising the power supply device according to claim 2 or 3 and the first circuit, wherein the device is detachably connected to another device having the second circuit.