JP2007124239A - Image storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve security for losing images, and at the same time, make it possible to efficiently perform memory processing of the images at a time of receiving power of a commercial power source and information of a signal line, and memorizing the images. <P>SOLUTION: The device is provided with a communication control unit 110 which receives the power of the commercial power source, and information from the signal line; and nonvolatile memory 109a and volatile memory 109b which store images. A CPU 101 discriminates whether the communication control unit 110 receives information from the signal line or not, and controls to store the image in the non-volatile memory 109a or volatile memory 109b based on the discrimination results. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image storage device that receives power from a commercial power source and a signal line.

  IEEE 802.3af-2003 (see, for example, Non-Patent Document 1) has been standardized, and PoE (Power over Ethernet (registered trademark)) compatible devices are appearing. Some PoE-compatible devices omit a power supply mechanism using a commercial power source such as an AC adapter. For example, a PoE (signal line) and a commercial power source are both provided with a power supply mechanism using a commercial power source for compatibility with conventional models. Many can receive power from

  On the other hand, the image storage function in the network camera has a function of accumulating and storing images at regular intervals according to the output of an external sensor or according to a schedule. In image storage processing in a network camera, a DRAM of a volatile memory is often used as a storage because it is inexpensive, does not have a limit on the number of rewrites, and is fast (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 10-257473 IEEE Standards 802.3af-2003

  In the PoE-compatible device, an operation mode in which a plurality of power receiving devices are connected to one power supply device is assumed. When the power consumption of a plurality of power receiving devices connected to the same power supply apparatus increases at the same time, it is considered that the capacity of the power supply apparatus is exceeded. In such a case, there is a possibility that the power supply by the power supply device stops.

  In addition, changing the Ethernet (registered trademark) cable, that is, changing the signal line, has less psychological resistance than changing the commercial power supply, so it is possible to connect or disconnect the cable at the hub or patch panel. There is sex. The image storage function, which is a function of the network camera, usually requires a storage area with a considerable capacity, and therefore an inexpensive volatile memory DRAM is used. This is because if the device configuration is such that all images are stored in a non-volatile memory such as a flash memory, problems such as an increase in product cost and a decrease in product life due to a limit on the number of rewrites occur. However, when power supply to an image storage device such as a network camera is stopped for the above reasons, there is a problem that an image stored in a volatile memory such as a DRAM is lost.

  The present invention has been made in view of the above-described problems. When receiving an image from a commercial power source and a signal line and storing an image, the present invention improves the safety against the loss of the image and efficiently stores the image. The purpose is to be able to do well.

  An image storage device according to the present invention includes a power receiving unit that receives power from a commercial power source and a signal line, a determination unit that determines whether the power receiving unit is receiving power from the signal line, and a nonvolatile memory that stores an image. And a volatile memory for storing an image, and a storage control unit for controlling the image to be stored in the nonvolatile memory or the volatile memory based on a determination result by the determination unit.

  According to the present invention, when receiving an image from a commercial power source and a signal line and storing an image, it is possible to improve the safety against the loss of the image and efficiently perform the image storing process.

  For example, if power is being received from a signal line, it is more likely that the signal line will be connected compared to a commercial power supply, so the image disappears by storing the image in nonvolatile memory. On the other hand, when receiving power from a commercial power supply, it is unlikely that the commercial power supply will be changed compared to changing the signal line. Image storage processing is performed efficiently by storing images. As a result, an optimal image storage process can be performed without being conscious of the power feeding method, and an image storage device with high fault tolerance can be provided.

  In addition, since it is possible to set whether or not to store an image in the nonvolatile memory, the user can specify a method for using the image storage area, and an image storage device with higher availability can be provided. it can. In addition, it is possible to set the frequency of storing the image in the nonvolatile memory according to the schedule. When receiving power from the signal line, the image is stored in the nonvolatile memory at the set frequency. Thus, an image storage device capable of a large-capacity image storage process even when receiving power from a signal line can be provided. In addition, when the compression format of the image is MPEG, the image stored in the non-volatile memory is an intra frame that has no correlation with the preceding and succeeding frames, so that the compression rate is higher and a large-capacity image can be stored. An image storage device can be provided.

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

FIG. 1 is a block diagram showing a schematic configuration of an image storage device according to an embodiment of the present invention.
In the image storage device of FIG. 1, reference numeral 101 denotes a CPU that performs overall control in the image storage device 100. An imaging unit 102 captures a moving image and a still image of the subject. Reference numeral 103 denotes a video signal processing unit that processes the image signal output from the imaging unit 102 to generate image data. Reference numeral 104 denotes an encoding / decoding unit that encodes and decodes still image data, moving image data, audio data, and music data. Among these, one or a plurality of data is stored in a program memory 108 to be described later. May be implemented by software.

  Reference numeral 105 in FIG. 1 denotes a microphone for capturing an audio signal. Reference numeral 106 denotes an audio signal control unit that controls voice input / output. Reference numeral 117 denotes a speaker that outputs an audio signal such as voice. Reference numeral 108 denotes a program memory for storing a program. Reference numeral 109 denotes a data memory for storing data. The data memory 109 includes a non-volatile memory 109a such as a flash memory and a volatile memory 109b such as an SRAM and a DRAM. Images are stored in the respective memories under the control of the CPU 101.

  A communication control unit 110 communicates with an external device or a network via the Ethernet (registered trademark) 112, receives power from the PoE (signal line) of the Ethernet (registered trademark) 112, and receives power from a commercial power source. Take control. Reference numeral 111 denotes a bus that connects the components of the image storage device 100. Reference numeral 112 denotes Ethernet (registered trademark), which can receive power through PoE (signal line).

FIG. 2 is a network configuration diagram when a network camera to which the image storage device according to the embodiment of the present invention is applied and a PoE-compatible Ethernet (registered trademark) hub are connected.
Reference numeral 201 in FIG. 2 denotes a management PC. Reference numeral 202 denotes a PoE-compatible Ethernet (registered trademark) hub. A network camera 203 is supplied with power from a PoE-compatible Ethernet (registered trademark) hub 202 via a signal line. Reference numeral 204 denotes a network camera to which the image storage device according to the present embodiment is applied. Power is supplied from the signal line, and power is supplied from a commercial power supply (AC 100 V, 50 Hz / 60 Hz) via the AC adapter 205. . In addition, for example, a device such as an IP phone may be connected to the PoE-compatible Ethernet (registered trademark) hub 202.

  The PoE-compatible Ethernet (registered trademark) hub 202 includes, for example, 48 ports of Ethernet (registered trademark) connection ports, but does not have the ability to simultaneously supply 15.4 W, the upper limit of PoE, to all ports. For this reason, a device that requires highly reliable operation is supplied with power from a commercial power source by the AC adapter 205, such as the network camera 204.

  FIG. 3 is a flowchart showing an image storage method in the image storage device according to the embodiment of the present invention. Prior to the processing in FIG. 3, it is assumed that the schedule and frequency have already been registered.

  First, in step S301, it is determined whether or not the CPU 101 is set to store the captured image in the nonvolatile memory 109a such as a flash memory.

  If the result of determination in step S301 is that the captured image is not set to be stored in the nonvolatile memory 109a, the process proceeds to step S306. In step S306, the CPU 101 stores the captured image in the volatile memory 109b, and ends the processing in the image storage method.

  On the other hand, if it is determined in step S301 that the captured image is set to be stored in the nonvolatile memory 109a, the process proceeds to step S302. In step S302, the CPU 101 determines whether power is being received from PoE (signal line).

  As a result of the determination in step S302, if power is not being received from PoE, it is considered that the frequency of power supply being interrupted is very low. Then, the process in the image storage method is terminated.

  On the other hand, if the result of determination in step S302 is that power is being received from PoE, the process proceeds to step S303. Subsequently, in step S303, the CPU 101 determines whether or not the frequency setting for storing the image in the nonvolatile memory 109a is set according to the schedule. Even when the schedule is not registered, it is determined that the frequency is not set here.

  As a result of the determination in step S303, if the frequency is set, the process proceeds to step S304. Subsequently, in step S304, the CPU 101 determines whether or not the current image is a specific frame. Here, the specific frame is a frame corresponding to the case where the frequency is set, and an intra frame when storing in the MPEG format.

  If it is determined in step S304 that the current image is a specific frame, or if it is determined in step S303 that the frequency is not set, the image should be saved even if the power supply is interrupted. In step S305, the CPU 101 stores the captured image in the volatile memory 109b. Thereafter, the processing in the image storage method is terminated.

  On the other hand, if the result of determination in step S304 is that the current image is not a specific frame, the process proceeds to step S306, where the captured image is stored in the volatile memory 109b as described above, and the processing in the image storage method ends. To do.

  According to the image storage device 100 according to the present embodiment, when receiving an image from a commercial power source and a signal line and storing an image, the image storage device 100 can improve the safety against image loss and efficiently perform the image storage process. Can do.

  Each unit of FIG. 1 constituting the image storage device 100 according to the present embodiment described above and each step of FIG. 3 showing the image storage method in the image storage device 100 are stored in a RAM or ROM of a computer. This can be realized by operating the program. This program and a computer-readable storage medium storing the program are included in the present invention.

  Specifically, the program is recorded in a storage medium such as a CD-ROM, or provided to a computer via various transmission media. As a storage medium for recording the program, a flexible disk, a hard disk, a magnetic tape, a magneto-optical disk, a nonvolatile memory card, and the like can be used in addition to the CD-ROM. On the other hand, as the transmission medium of the program, a communication medium (wired line such as an optical fiber, etc.) in a computer network (LAN, WAN such as the Internet, wireless communication network, etc.) system for propagating and supplying program information as a carrier wave A wireless line or the like.

  In addition, the functions of the image storage device 100 according to the present embodiment are realized by executing a program supplied by the computer, and an OS (operating system) or other application in which the program is running on the computer. When the functions of the image storage device 100 according to the present embodiment are realized in cooperation with software, all or part of the processing of the supplied program is performed by a function expansion board or a function expansion unit of the computer. Such a program is also included in the present invention when the functions of the image storage device 100 according to the present embodiment are realized.

1 is a block diagram showing a schematic configuration of an image storage device according to an embodiment of the present invention. 1 is a network configuration diagram when a network camera to which an image storage device according to an embodiment of the present invention is applied and a PoE-compatible Ethernet (registered trademark) hub are connected. FIG. It is a flowchart which shows the image storage method in the image storage device which concerns on embodiment of this invention.

Explanation of symbols

100 Image storage device 101 CPU
102 Imaging unit 103 Video signal processing unit 104 Encoding / decoding unit 105 Microphone 106 Audio signal processing unit 107 Speaker 108 Program memory 109 Data memory 109a Non-volatile memory 109b Volatile memory 110 Communication control unit 111 Bus 112 Ethernet (registered trademark)
201 Management PC
202 PoE compatible Ethernet (registered trademark) hub 203, 204 Network camera 205 AC adapter

Claims (5)

Power receiving means for receiving power from a commercial power source and a signal line;
Determining means for determining whether the power receiving means is receiving power from the signal line;
A non-volatile memory for storing images;
Volatile memory for storing images,
An image storage device comprising: a storage control unit configured to control an image to be stored in the nonvolatile memory or the volatile memory based on a determination result by the determination unit.   The storage control unit controls the storage unit to store an image in the nonvolatile memory when the determination unit determines that the power reception unit is receiving power from the signal line. The image storage device described. Further comprising storage setting means for setting whether to store an image in the nonvolatile memory;
The storage control means is the case where the setting is made by the storage setting means, and when the determination means determines that the power reception means is receiving power from the signal line, the storage control means The image storage device according to claim 1, wherein the image storage device is controlled so as to be stored in a memory. A frequency setting means for setting a frequency of storing an image in the nonvolatile memory according to a schedule;
The storage control unit stores an image in the nonvolatile memory at a frequency set by the frequency setting unit when the determination unit determines that the power receiving unit is receiving power from the signal line. The image storage device according to claim 1, wherein the image storage device is controlled so as to store an image in the volatile memory except for the frequency.   5. The image storage device according to claim 4, wherein when the image compression format is MPEG, the image stored in the nonvolatile memory is an intra frame.

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