US-12627906-B2 - Image capturing apparatus, method for controlling same, and storage medium for controlling power supply to a load circuit according to the state of the apparatus

Abstract

An apparatus includes a load circuit, a power source, a storage device, an obtaining unit that obtains a value of a resistance of the storage device, and a control unit. The control unit, in a first state, performs control so that power is supplied from the power source to the load circuit without power being supplied from the storage device to the load circuit and, in a second state of the apparatus, performs control so that power is supplied from the power source and the storage device to the load circuit, and the control unit changes limitation of a current value of a current supplied from the power source to the load circuit depending on the value of the resistance.

Inventors

• Yudai Itoi
• Yuki Tsujimoto
• Takuma Iwagami

Assignees

• CANON KABUSHIKI KAISHA

Dates

Publication Date

20260512

Application Date

20240930

Priority Date

20231002

Claims (20)

1. 1 . An apparatus comprising: a load circuit; a power source; a power storage device; at least one processor; and a memory coupled to the at least one processor, the memory storing instructions that, when executed by the processor, causes the at least one processor to function as: an obtaining unit that obtains a value of a resistance of the power storage device, a control unit that controls power supply to the load circuit according to a state of the apparatus, wherein the control unit, in a first state of the apparatus, performs control so that power is supplied from the power source to the load circuit without power being supplied from the power storage device to the load circuit and, in a second state of the apparatus in which a maximum power consumption of the load circuit is greater than in the first state, performs control so that power is supplied from the power source and the power storage device to the load circuit, and the control unit changes limitation of a current value of a current supplied from the power source to the load circuit depending on the obtained value of the resistance of the power storage device.
2. 2 . The apparatus according to claim 1 , wherein the load circuit is an image capturing sensor.
3. 3 . The apparatus according to claim 1 , wherein the power storage device is an electric double layer capacitor or a solid-state battery.
4. 4 . The apparatus according to claim 1 , wherein the control unit includes a first mode in which a current of a first current value is supplied from the power source to the load circuit and a second mode in which a current of a second current value less than the first current value is supplied from the power source to the load circuit.
5. 5 . The apparatus according to claim 4 , wherein the control unit switches an impedance between the power source and the load circuit to switch between the first mode and the second mode.
6. 6 . The apparatus according to claim 4 , wherein the control unit changes a threshold of a current value supplied from the power source to the load circuit to switch between the first mode and the second mode.
7. 7 . The apparatus according to claim 4 , wherein in a case where the resistance of the power storage device is less than a predetermined value, the control unit supplies a current from the power source to the load circuit in the first mode, and in a case where the resistance of the power storage device is equal to or greater than the predetermined value, the control unit supplies the current from the power source to the load circuit in the second mode.
8. 8 . The apparatus according to claim 1 , wherein the obtaining unit calculates a value of an equivalent series resistance of the power storage device and obtains the calculated value of the equivalent series of the power storage device as the value of the resistance of the power storage device.
9. 9 . The apparatus according to claim 8 , wherein the obtaining unit uses a current value of a current flowing through the load circuit, a current value of a current supplied from the power source to the load circuit, and an impedance of the power source to calculate an equivalent series resistance of the power storage device.
10. 10 . The apparatus according to claim 8 , wherein the obtaining unit uses a current value of a current flowing through a test circuit connect to the power source and the power storage device, a current value of a current supplied from the power source to the test circuit, and an impedance of the power source to calculate an equivalent series resistance of the power storage device.
11. 11 . The apparatus according to claim 9 , wherein according to the calculated value of an equivalent series resistance of the power storage device, the control unit predicts a maximum current of the power source and, in a case where the predicted maximum current is greater than a predetermined value, limits a current value of a current supplied from the power source to the load circuit.
12. 12 . The apparatus according to claim 8 , wherein according to the calculated value of an equivalent series resistance of the power storage device, the control unit predicts a voltage supplied to the load circuit and, in a case where a predicted voltage is less than a predetermined value, limits operation of a specific mode of the apparatus.
13. 13 . The apparatus according to claim 12 , wherein the specific mode is a still image capturing mode.
14. 14 . The apparatus according to claim 12 , wherein the specific mode is a still image continuous shooting mode for capturing still images at a speed faster than a predetermined speed.
15. 15 . The apparatus according to claim 12 , wherein the specific mode is an image capturing mode for simultaneously reading out signals of a plurality of pixels of an image capturing sensor.
16. 16 . The apparatus according to claim 1 , further comprising: a charging circuit that uses power from the power source to charge the power storage device.
17. 17 . A method for controlling an apparatus including a load circuit, a power source, and a power storage device, the method comprising: obtaining a value of a resistance of the power storage device; controlling power supply to the load circuit according to a state of the apparatus, wherein in a first state of the apparatus, control is performed so that power is supplied from the power source to the load circuit without power being supplied from the power storage device to the load circuit and, in a second state in which a maximum power consumption of the load circuit is greater than in the first state, control is performed so that power is supplied from the power source and the power storage device to the load circuit, and in the controlling, limitation of a current value of a current supplied from the power source to the load circuit is limited depending on the obtained value of the resistance of the power storage device.
18. 18 . The method according to claim 17 , wherein the obtaining calculates a value of an equivalent series resistance of the power storage device and obtains the calculated value of the equivalent series of the power storage device as the value of the resistance of the power storage device.
19. 19 . A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method for controlling an apparatus including a load circuit, a power source, and a power storage device, the method including: obtaining a value of a resistance of the power storage device, controlling power supply to the load circuit according to a state of the apparatus, wherein in a first state of the apparatus, control is performed so that power is supplied from the power source to the load circuit without power being supplied from the power storage device to the load circuit and, in a second state in which a maximum power consumption of the load circuit is greater than in the first state, control is performed so that power is supplied from the power source and the power storage device to the load circuit, and in the controlling, limitation of a current value of a current supplied from the power source to the load circuit is limited depending on the obtained value of the resistance of the power storage device.
20. 20 . The non-transitory computer-readable storage medium according to claim 19 , wherein the obtaining calculates a value of an equivalent series resistance of the power storage device and obtains the calculated value of the equivalent series of the power storage device as the value of the resistance of the power storage device.

Description

TECHNICAL FIELD The aspect of the embodiments relates to a technique for driving a load circuit with a power storage device in an image capturing apparatus. DESCRIPTION OF THE RELATED ART An image capturing apparatus in which rolling shutter distortion is reduced without using a mechanical shutter by installation of an image capturing sensor that can simultaneously read out a plurality of pieces of pixel data has been proposed. However, when many pieces of pixel data are read out at high-speeds, the peak current of the image capturing sensor increases. When the peak current increases, the current supplied from a battery of the image capturing apparatus may exceed a tolerance value, causing the voltage of the battery to drop and cause a system failure. Also, when the peak current increases, a voltage drop may occur due to line resistance, and if the voltage drops below the minimum drive voltage of the image capturing apparatus, a system failure may occur. A conceivable way of avoiding a system failure includes stopping the operations of the image capturing apparatus before the battery voltage becomes equal to or less than a predetermined value. However, in this case, the operable time of the image capturing apparatus is significantly reduced. As described above, a known method for handling an increase in peak current includes reducing a current supplied from the battery by supplying a current from a power storage device such as an electric double layer capacitor or the like. For example, Japanese Patent Laid-Open No. 2013-081329 discloses a method for reducing the current when a motor is driven using a power storage device. Japanese Patent Laid-Open No. 2008-061492 discloses a method for reducing peak current by limiting the current of a main power source and using a power storage device as an auxiliary power source. However, since an electric double layer capacitor or similar power storage device is configured to a plurality of cells connected in series, there may be cases where the equivalent series resistance (ESR) is high. Also, it has the property of the ESR increasing in low-temperature environments due to temperature characteristics. Furthermore, it has the properties of degrading in terms of electrical characteristics and increasing in terms of ESR when a voltage is applied for a long period of time in a high-temperature environment. When the ESR of the power storage device increases, the power supply from the power storage device becomes difficult to perform. Also, at the time of charging and discharging of the power storage device, loss generated by the ESR increases. The technique disclosed in Japanese Patent Laid-Open No. 2013-081329 described above has an issue in that, in a case where the ESR of the power storage device is high, the current supplied from the power storage device is reduced, causing the peak current of the battery to be unable to be sufficient reduced. Also, the technique described in Japanese Patent Laid-Open No. 2008-061492 has an issue in that, in a case where the current of the main power source is limited, power is supplied solely from the power storage device. Thus, charging and discharging of the power storage device is frequently performed, which increases the loss due to ESR. SUMMARY According to a first aspect of the embodiments, there is provided an apparatus comprising: a load circuit; a power source; a storage device; at least one processor; and a memory coupled to the at least one processor, the memory having instructions that, when executed by the processor, causes the at least one processor to function as an obtaining unit that obtains a value of a resistance of the storage device, a control unit that controls power supply to the load circuit according to a state of the apparatus, wherein the control unit, in a first state of the apparatus, performs control so that power is supplied from the power source to the load circuit without power being supplied from the storage device to the load circuit and, in a second state of the apparatus in which a maximum power consumption of the load circuit is greater than in the first state, performs control so that power is supplied from the power source and the storage device to the load circuit, and the control unit changes limitation of a current value of a current supplied from the power source to the load circuit depending on the obtained value of the resistance of the storage device by the obtaining unit. According to a second aspect of the embodiments, there is provided a method for controlling an apparatus including a load circuit, a power source, and a storage device, the method comprising: obtaining a value of a resistance of the storage device; controlling power supply to the load circuit according to a state of the apparatus, wherein in a first state of the apparatus, control is performed so that power is supplied from the power source to the load circuit without power being supplied from the storage device to the l