Power supply control circuit and image forming apparatus

• US 9,927,823 B2
• Filed: 09/13/2016
• Issued: 03/27/2018
• Est. Priority Date: 09/15/2015
• Status: Active Grant

• Current Assignee: KYOCERA Document Solutions, Inc. (Kyocera Corporation)
• Original Assignee: KYOCERA Document Solutions, Inc. (Kyocera Corporation)
• Inventors: Umezawa, Hideo
• Primary Examiner(s): WALSH, RYAN D
• Application Number:
  US15/263,627
• Publication Number:
  US 20170075369A1
• Time in Patent Office: 560 Days
• CPC Class Codes: G03G 15/80 Details relating to power supplies, circuits boards, electrical connections
• CPC Class Codes: G05F 1/462 as a function of the requirements of the load, e.g. delay, temperature, specific voltage/current characteristic
• CPC Class Codes: G05F 1/577 for plural loads
• CPC Class Codes: H02J 1/00 Circuit arrangements for dc mains or dc distribution networks

Abstract

A power supply control circuit includes a plurality of ports, and a plurality of power supply units that each turn on and off the power supply from the power source to the load connected to the port. The power supply control circuit also includes an identification information acquisition unit, a sequence information storage unit, and a switch control unit. The identification information acquisition unit acquires identification information from the loads connected to the respective ports. The sequence information storage unit stores therein power-up sequence information and power-down sequence information specified for each of the loads. The switch control unit causes the power supply unit to turn on and off the power supply to the load corresponding to the identification information, according to the power-up sequence information and the power-down sequence information specified for the load.

Claims

1. A power supply control circuit that controls power supply when supplying power from a power source to a plurality of loads, the power supply control circuit comprising:

a plurality of ports to which the plurality of loads are respectively connected, and a plurality of power supply units that respectively turn on and off the power supply from the power source to the plurality of loads respectively connected to the plurality of ports;

an identification information acquisition unit that acquires identification information proper to each of the loads, from the loads connected to the respective ports;

a sequence information storage unit that stores therein power-up sequence information and power-down sequence information specified with respect to each of the plurality of loads; and

a switch control unit that reads out, from the sequence information storage unit, the power-up sequence information and the power-down sequence information with respect to the load corresponding to the identification information acquired by the identification information acquisition unit, and causes the power supply unit to turn on and off the power supply to the load corresponding to the identification information, according to the power-up sequence information and the power-down sequence information read out,

wherein the sequence information storage unit stores therein, as the power-up sequence information, a voltage rise rate during a period in which a voltage applied when the power supply from the power source to the load is started reaches a driving voltage appropriate for the load.

2. The power supply control circuit according to claim 1, further comprising:

a pulldown resistor that can be connected to and disconnected from a corresponding one of the ports;

a connection status detection unit that detects whether the load is connected to a corresponding one of the ports; and

a resistor connection control unit that connects the pulldown resistor to the port with respect to which the connection status detection unit has decided that the load is not connected.

3. An image forming apparatus to which an optional apparatus can be retrofitted, comprising the power supply control circuit according to claim 1,

wherein the power supply control circuit controls power supply to the optional apparatus, regarding the optional apparatus as the load.

4. A power supply control circuit that controls power supply when supplying power from a power source to a plurality of loads, the power supply control circuit comprising:

a plurality of ports to which the plurality of loads are respectively connected, and a plurality of power supply units that respectively turn on and off the power supply from the power source to the plurality of loads respectively connected to the plurality of ports;

an identification information acquisition unit that acquires identification information proper to each of the loads, from the loads connected to the respective ports;

a sequence information storage unit that stores therein power-up sequence information and power-down sequence information specified with respect to each of the plurality of loads; and

a switch control unit that reads out, from the sequence information storage unit, the power-up sequence information and the power-down sequence information with respect to the load corresponding to the identification information acquired by the identification information acquisition unit, and causes the power supply unit to turn on and off the power supply to the load corresponding to the identification information, according to the power-up sequence information and the power-down sequence information read out,

wherein the sequence information storage unit stores therein, as the power-down sequence information, a voltage drop rate during a period from a time that the power supply from the power source to the load is disconnected until a time that the voltage drops to 0 V.

5. A power supply control circuit that controls power supply when supplying power from a power source to a plurality of loads, the power supply control circuit comprising:

a plurality of ports to which the plurality of loads are respectively connected, and a plurality of power supply units that respectively turn on and off the power supply from the power source to the plurality of loads respectively connected to the plurality of ports;

an identification information acquisition unit that acquires identification information proper to each of the loads, from the loads connected to the respective ports;

a sequence information storage unit that stores therein power-up sequence information and power-down sequence information specified with respect to each of the plurality of loads; and

a switch control unit that reads out, from the sequence information storage unit, the power-up sequence information and the power-down sequence information with respect to the load corresponding to the identification information acquired by the identification information acquisition unit, and causes the power supply unit to turn on and off the power supply to the load corresponding to the identification information, according to the power-up sequence information and the power-down sequence information read out,

wherein the power supply control circuit further comprises;

a voltage detection unit that detects a voltage supplied to each of the loads connected to the respective ports from the power source through the power supply unit; and

a sequence information alteration unit that alters, when a voltage change during power-up for the load detected by the voltage detection unit is different from a voltage change stored in association with the power-up sequence information specified for the load, a duty ratio of a drive control signal corresponding to the power-up sequence information so as to make the voltage change of the load detected by the voltage detection unit closer to the voltage change stored in association with the power-up sequence information.