JP2008099026A - Power supply switching circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch power supply only when requiring high electric power for pan/tilt operations of a high-speed camera, which exceeds PoE (Power over Ethernet(R)) power supply capability, to use advanced functions. <P>SOLUTION: In a power supply switching circuit for a network camera, PoE power supply input and general-purpose power supply input are simultaneously connected to a device, and power supply for the device is switched between the PoE power supply 14 and a general-purpose power supply 13 to be supplied. When a client acquires a control right for operations of the network camera, the power supply switching circuit switches power supply from the PoE power supply input 13 to the power supply input 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply switching circuit. Specifically, the power from a PoE (Power over Ethernet (registered trademark)) power supply conforming to the power supply specified by the standard IEEE 802.3af, which supplies power using a LAN cable, and a general-purpose power supply such as an AC adapter are switched and used. The present invention relates to a power supply switching circuit for equipment.

  Power over Ethernet (registered trademark) (hereinafter PoE), which supplies power to devices using a LAN cable for data communication, has been marketed since the standardization by IEEE 802.3af of Non-Patent Document 1 Has appeared in.

  Also, a system in which video and audio are distributed from a network camera serving as a server via a network and viewed with a client such as a PC (Personal Computer) has become common.

  For example, a Canon WebView system can be cited as a good example, and there is a camera control right that allows only a specific client to control the pan / tilt operation of the camera as disclosed in Patent Document 1.

  In an example of a conventional device such as a network camera having a PoE power input and a general power input, the PoE power is given priority when the PoE power input and the general power input such as an AC adapter are connected simultaneously.

  This is because the voltage of the PoE power supply is + 48V, and the power supply voltage of the AC adapter etc. is generally a low +12 to + 13V, so it is easy to make a switching circuit, and the PoE power supply This is because supply requires a procedure such as authentication. Further, it takes about 1 second until the power supply of + 48V is supplied, and therefore, switching to the PoE power supply is not performed smoothly due to the unexpected disconnection of the AC adapter power supply. .

  A network camera with a high-speed pan / tilt mechanism performs high-speed pan / tilt operations when operating with an AC adapter, but when operating with a PoE power supply, the network camera has a low speed so as not to exceed the allowable power supply of PoE. Pan / tilt operation was performed.

Japanese Patent Laid-Open No. 10-42278 IEEE 802.3af

  The present invention requires high power, such as pan / tilt operation of a high-speed camera exceeding the PoE power supply capability, when a PoE power supply priority camera is supplied with power from PoE at the same time while using an AC adapter. This solves the problem that the function cannot be used.

The power supply switching circuit of the present invention is a power supply switching circuit for a network camera in which a PoE power supply input and a general-purpose power supply input are simultaneously connected to a device, and power supply to the device is switched between a PoE power supply and a general-purpose power supply. The power supply is switched from the PoE power input to the general-purpose power input when the client obtains the control right of the operation of the network camera.
The power supply switching circuit of the present invention is a network camera power supply switching circuit in which a PoE power supply input and a general-purpose power supply input are simultaneously connected to a device, and power supply to the device is switched between a PoE power supply and a general-purpose power supply. The power supply is switched from the PoE power supply input to the general-purpose power supply input when a pan / tilt operation command of the network camera is received from a client.

  In the present invention, when the control right of the pan / tilt operation of the network camera is acquired, the power supply is switched from the PoE power input to the general-purpose power input, so that the pan / tilt operation of the high-speed camera exceeding the PoE power supply capability, etc. Functions that require high power can be used.

  In the present invention, when a pan / tilt operation command of the network camera is received from a client, the power supply is switched from a PoE power input to a general-purpose power input. When the pan / tilt operation is completed, the power supply is switched to a PoE power input. Switch to.

  This makes it possible to use advanced functions by switching the power supply only when high power is required, such as high-speed camera pan / tilt operation exceeding the PoE power supply capability.

(First embodiment)
FIG. 1 is a preferred embodiment of a power supply switching circuit in a network camera of the present invention. In FIG. 1, reference numeral 10 denotes a network camera of this embodiment. Reference numeral 1 denotes a CPU unit that controls the network camera, and 2 denotes a network unit that performs Ethernet (registered trademark) communication. An imaging / image processing unit 3 includes an imaging unit including a lens and an imaging element and an image processing unit that performs digital processing.

  Reference numeral 4 denotes a pan-tilt motor drive unit for performing pan / tilt operation of the network camera, 5 a display unit such as an LED indicating the state of the power supply, and 6 a power supply switching unit for switching the AC adapter power supply PoE power supply. 6 will be described in more detail later.

  7 is a DC13V input connector from the cable 13 of the AC adapter, and 8 is an RJ45 connector to which the Ethernet (registered trademark) cable 14 is connected.

  In FIG. 1, power is supplied to the network camera 10 from 7 or 8. Here, the inside of the power supply switching unit 6 will be described with reference to FIG.

  In FIG. 2, 21 is a PoE power receiving circuit for receiving a PoE power supply, 22 is a sensor for detecting the power supply of the AC adapter, 23 is a sensor for detecting the power supply from the PoE power supply, and 24 is a connection of the PoE power supply. The initial value is ON with the switch (SW1) to be switched.

  Reference numerals 25 and 26 denote diodes for controlling the power from the AC adapter and the power from the PoE. When both power sources are connected simultaneously, the PoE power having a high voltage is preferentially supplied and the backflow to the AC adapter is prevented. It is out.

  Reference numeral 27 denotes a DC-DC converter, which is converted into a power supply circuit voltage inside the device and power is supplied to each circuit. A control unit 28 communicates with the CPU unit 1 to transmit sensor information of the sensor 22 and the sensor 23 and controls the state of the switch 24.

  In addition, the diodes 25 and 26 may include a switch 24 and be configured by a switch such as an FET to switch between the AC adapter and the PoE power source.

  The switching operation in the control unit 28 will be described with reference to the flowchart of FIG.

  First, in step S302, the CPU unit 1 confirms acquisition of the camera control right. If No, the process proceeds to step S303, and SW1 of 24 is turned on and the process returns to step S302.

  On the other hand, in the case of Yes, the process proceeds to step S304, and the sensor 22 checks whether there is power supply from the AC adapter. If No in step S304, the process proceeds to step S306, SW1 is turned on, and the process returns to step S302.

  On the other hand, if Yes, the process proceeds to step S305, where SW1 is turned off and the process returns to step S302. This control is performed by one CPU unit and 28 control units.

  That is, when the video distribution standby state that does not exceed the allowable range of PoE power supply or when the camera control right of the client instructing the pan / tilt operation is not taken and only the video distribution is performed, the power switching unit 6 operates to supply power from the PoE power source of 8.

  Next, in order to perform the pan / tilt operation of the camera, when the control right of the camera is taken on the video viewer side, the power supply switching unit in preparation for the high-speed pan / tilt operation that may exceed the allowable range of PoE power supply 6 switches to power supply from 7 AC adapter.

  However, when there is no power supply from the AC adapter, power is supplied from the PoE power of 8, and the CPU unit 1 controls the motor drive unit 4 so as not to perform high-speed pan / tilt operation, and the PoE power supply is allowed. Do not exceed the range.

  In addition, when the power is supplied only from the AC adapter so that 22 sensors are detected but 23 sensors are not detected, the CPU unit 1 performs control so as not to perform the series of operations of FIG. It may be configured.

  In addition, in order to notify which power is supplied from the AC adapter or the PoE power source, the lighting and color of the 5 LEDs may be controlled.

(Second Embodiment)
Next, a second embodiment for switching when a pan / tilt operation is requested will be described with reference to the flowchart of FIG. Since the configuration of the network camera 10 is the same as that in FIG. 1, the description thereof is omitted here.

  In step S401, if the CPU unit 1 issues a pan / tilt operation command, the process proceeds to step S402, and the sensor 22 checks whether there is power supply from the AC adapter.

  In the case of No in step S402, the process proceeds to step S403, and SW1 is turned on, a low-speed pan / tilt operation is performed in step S404, and the end of the pan / tilt operation is confirmed in step S405.

  If No, the process returns to Step S405 to perform a confirmation operation. If Yes, the process ends at Step S410. On the other hand, if Yes in step S402, SW1 is turned off in step S406, a high-speed pan / tilt operation is performed in step S407, and the end of the pan / tilt operation is confirmed in step S408.

  If No, the process returns to step S409 to perform a confirmation operation. If Yes, SW1 is turned on in step S409, and then the pan / tilt operation ends in step S410.

  As described above, in the present embodiment, the presence or absence of power supply from the AC adapter is confirmed only when the camera that is normally operated by the PoE power supply performs the pan / tilt operation. When the camera is supplied, the power supply is switched to the AC adapter. A high-speed pan / tilt operation is performed, and when the pan / tilt operation is completed, the operation is switched to the PoE power source operation again.

  Furthermore, in this embodiment, 22 sensors are detected, but the CPU unit 1 does not perform the series of operations in FIG. 4 when receiving power from only the AC adapter so that 23 sensors are not detected. It may be configured to control as described above.

  In addition, in order to notify which power is supplied from the AC adapter or the PoE power source, the lighting and color of the 5 LEDs may be controlled.

It is a block diagram of the network camera which concerns on embodiment of this invention. It is a figure which shows the internal structure of the power supply switching part which concerns on embodiment of this invention. It is a flowchart of the power supply switching control which concerns on the 1st Embodiment of this invention. It is a flowchart of the power supply switching control which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 CPU part 2 Network part 3 Image pick-up / image processing part 4 Pan / tilt motor control part 5 Power supply display part 6 Power supply switching part 7 Power supply connector 8 RJ45 connector 10 Network camera 21 PoE power receiving part 22 Sensor 23 Sensor 24 Changeover switch 25 Diode 26 Diode 27 DC-DC converter 28 Power supply switching control unit

Claims (3)

A network camera power supply switching circuit that connects a PoE power supply input and a general-purpose power supply input to a device at the same time, and supplies power to the device by switching between a PoE power supply and a general-purpose power supply.
A network camera power supply switching circuit, wherein when a client obtains the control right of the operation of the network camera, the power supply is switched from the PoE power supply input to the general-purpose power supply input. A network camera power supply switching circuit that connects a PoE power supply input and a general-purpose power supply input to a device at the same time, and supplies power to the device by switching between a PoE power supply and a general-purpose power supply.
A power supply switching circuit for a network camera, wherein the power supply is switched from the PoE power input to the general-purpose power input when a pan / tilt operation command of the network camera is received from a client.   3. The network camera power switching circuit according to claim 2, wherein when the pan / tilt operation is completed, the power supply is switched to the PoE power input.

Images