JPH114410A - Realtime video recording device, method therefor, and disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a realtime video recording device at a low cost with a simple configuration by entering video data to a primary storage means, tentatively storing the data in a ring form, transferring and storing video data to a secondary storage means, starting the secondary storage means in response to a recording instruction entry and recording the video data to the secondary storage means, while tracing back by a prescribed time from the end of start. SOLUTION: Video data are periodically overwritten in a DPRAM 21 of a primary storage section 2. When a recording instruction is given to an instruction input section 5, a start time measurement circuit 41 starts a hard disk unit 3 for measuring the time until the start is completed. A start time measurement circuit 41 gives the the information of start time to a start position decision circuit 44. A time dating back from an input point of time of the recording instruction is set to an advance recording time setting section 42. According to the recording instruction to a control section 4, the video data stored in the primary storage section 2 dating back by a time, including the time until the end of the start of the hard disk unit 3 are recorded in the hard disk unit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television
In a computer system having a TR, a surveillance camera, and a television reception function, broadcasted and photographed images are always stored in a primary memory for several seconds to several minutes, and a user issues a recording command to store a secondary memory. The present invention relates to a real-time video recording device and method for recording video data retroactively from the time of activation, and a disk device.

[0002]

2. Description of the Related Art In recent years, the capacity and cost of semiconductor memories have been increasing, and video data can be stored for only a few seconds to several minutes. Utilizing this, video data is always recorded in the semiconductor memory, and in response to a recording command, a surveillance image recording device that records video data retroactively for a certain period of time from that point in time, or real time that instantly reproduces missed videos Video recording devices have been developed.

An example of the above-described conventional monitoring image recording apparatus will be described below with reference to the drawings.

FIG. 8 is a block diagram showing a conventional monitoring image recording apparatus. In FIG. 8, reference numeral 105 denotes a sensor that generates an alarm when a human approaches, and outputs the alarm to the recording / reproducing apparatus 102. The recording / reproducing device 102 includes the camera 1
, An A / D converter 121 for converting an analog image signal input from the A. 01 into a digital image signal, a V-RAM 123 for temporarily storing the digital image signal, and an A / D converter 1
An image signal switching circuit 122 for switching the digital image signal from the V-RAM 123 and the digital image signal from the V-RAM 123; a compression / expansion unit 124 for compressing the image signal or expanding the compressed image signal; , A second switch 126, a recording memory 127 for recording an image signal, and a pre-recording memory 1 for constantly recording an image signal from the camera 101.
28, A / D converter 121, image signal switching circuit 1
22, a control unit 129 for controlling operations of the compression / decompression unit 124, the first switch 125, the second switch 126, etc., and a D / A conversion unit 131 for converting a digital image signal into an analog image signal and outputting it to the monitor 103 And

The operation of the monitoring image recording apparatus configured as described above will be described below.

First, a normal recording operation without an alarm input from the sensor 105 will be described. An analog image signal obtained from the camera 101 to be pre-recorded is digitally converted by the A / D
Once stored in the RAM 123, the compression / decompression unit 12
The compression-processed image signal is recorded in the pre-recording memory 128 via the first switch 25. Note that the pre-recording memory has only a capacity for storing image signals for four frames, and the compressed image signal from the camera 101 is continuously overwritten and recorded in the memory area for four frames.

Next, a recording operation when an alarm is input from the sensor 105 will be described. For a predetermined time after the alarm is input from the sensor 105, the image signal obtained from the camera 101 to be pre-recorded is digitally converted by the A / D converter 121 and VR is performed.
Once stored in the AM 123, the compression / decompression unit 124
The compression-processed image signal is recorded in the recording memory 127 via the first switch 25 and the second switch 26. After a lapse of a predetermined time, the first switch 125 is opened, while the second switch 12
6 switches to a state where it is connected to the pre-recording memory 128 side. And the pre-recording memory 128
Is recorded in the recording memory 127 through the second switch 126. At this time, in the recording memory 127,
The image signals for four frames immediately before the alarm input are stored in addresses smaller than the image signals immediately after the alarm input. That is, these image signals are stored in the recording memory 127 with time. When the image signals are read out in the order of the address numbers, the image signals are correctly reproduced with time (Japanese Patent Laid-Open No. 9-46636).

Next, an example of the above-described conventional real-time video recording apparatus will be described with reference to the drawings.

FIG. 9 is a block diagram showing a conventional real-time video recording apparatus. In FIG. 8, 7 is a microcomputer, 6 is a command input unit for inputting a recording / reproduction command, and 1 is a video input unit for inputting a video signal. Reference numeral 2 denotes a primary storage unit for temporarily storing the video data from the video input unit, and reference numeral 3 denotes a hard disk device for recording the video stored in the primary storage unit 2.

The operation of the real-time video recording apparatus configured as described above will be described below.

First, a normal operation in which no command for recording is given from the command input unit 6 will be described. Image data from the video input unit 1 is stored in the primary storage unit 2 through the data bus under the control of the microcomputer 7. The video data stored in the primary storage unit 2 is recorded in a specific area of the recording medium of the hard disk device 3, and the logical address on the recording medium at the time of recording is managed by the microcomputer 7; The information is transmitted to the hard disk device 3 through the section 2. In addition, since the transfer speed of the data bus is different from the transfer speed to the hard disk device 3, the primary storage unit 2 has a function of absorbing the difference in transfer speed. The microcomputer 7 manages logical addresses so that the video data is overwritten and recorded in a ring shape on the recording medium of the hard disk device 3. That is, control is performed such that video data is sequentially recorded from the head logical address of the specific area on the recording medium, and if the video data is recorded up to the last logical address of the specific area, recording is performed again from the head logical address.

Next, a recording operation when a recording instruction is input from the command input unit 6 will be described. When a recording instruction is input from the command input unit 6, the microcomputer 7
Recognizes the recording instruction and sends the logical address of the movement destination and the movement command through the primary storage unit 2 so that the video data of the specific area which is overwritten and recorded is moved to another area on the recording medium of the hard disk drive 3. Issue a command to 3. By this operation, the video data of the specific area is stored in another area on the recording medium.

[0013]

However, in the configuration of the monitoring image recording apparatus as described above, the recording memory 127 must be maintained in a recordable state at all times. Therefore, when a VTR is used for the recording memory 127, However, there is a problem in that the VTR head is worn and the tape is damaged due to the loading state of the tape, which affects the life and reliability. When a disk-type recording device is used for the recording memory 127, the disk-type recording medium must be constantly rotated, so that there is a problem that the life of a spindle motor for rotating the disk-type recording medium is shortened. . When a semiconductor memory is used as the recording memory 127, there is a problem that the recording time is shortened.

Further, when the disk type recording medium is rotated to a recordable state according to the input of a recording instruction such as an alarm, or when a VTR tape is loaded to a recordable state, the recording instruction enters the recordable state. However, there is a problem that a video signal input from a camera or the like is not recorded in a few seconds before the recording.

Further, in the configuration of the real-time video recording apparatus as described above, a primary storage unit for absorbing the transfer speed of the data bus for inputting the video data and the data transfer speed of the hard disk drive is required, which increases the cost. Had the problem of In addition, since the microcomputer 7 needs to finely manage the logical address of the recording medium of the hard disk device, there is a problem that the load on the microcomputer 7 becomes heavy.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a real-time video recording apparatus for recording video data stored in a pre-recording memory into a recording memory device retroactively for a certain period of time after the start of the recording memory device. Another object of the present invention is to provide a disk device for recording a real-time video with a simple and inexpensive configuration.

[0017]

In order to solve the above-mentioned problems, a real-time video recording apparatus according to the present invention comprises a video input means for inputting video data, and a primary memory for temporarily storing the video data in a ring shape. Storage means, a secondary storage means for storing video data of the primary storage means, an instruction input means for inputting a recording instruction, and activating the secondary storage means in response to the recording instruction input and going back a predetermined time from the completion of activation. And a control means for recording video data in the secondary storage means.

[0018] The video input means may include a compression means for compressing video data. The control unit includes a start-up time measuring unit that measures a time from when the recording instruction is input to when the secondary storage unit is completely started up, and a pre-recording time setting unit that sets a time that goes back from the input time of the recording instruction. Transfer rate input means for inputting a transfer rate of the video data; start of determining a video data read start position of the primary storage means from the activation time measuring means, the pre-recording time setting means, and the transfer rate input means; Position determining means.

The control means includes a start time input means for inputting a provisional time from when the recording instruction is input to when the secondary storage means is started, and a pre-recording for setting a time retroactive from the input time of the recording instruction. Time setting means, transfer rate input means for inputting a transfer rate of the video data,
The image processing apparatus may further include a start position determining unit that determines a start position of reading the video data from the primary storage unit from the start time input unit, the pre-recording time setting unit, and the transfer rate input unit.

[0020] The capacity of the primary storage means is such that the video data is stored within a time obtained by adding the pre-recording time set by the pre-recording time setting means and the starting time measured by the starting time measuring means. You may comprise so that it may become larger than the amount transferred to a storage means.

A real-time video recording method according to the present invention is a real-time video recording apparatus including a primary storage means for temporarily storing video data in a ring shape and a secondary storage means for storing video data of the primary storage means. A) inputting video data; and b) determining whether there is free space required for storing the video data in the primary storage means. Stores the video data in the primary storage means, and secures the free space by releasing the oldest video data stored in the primary storage means when the free space is insufficient. Storing the video data in the reserved free space; c) inputting a recording instruction; and d) determining whether the secondary storage means has been started in response to the recording instruction input. Determining that the activation has not been completed and, if not activated, activating the secondary storage means; and e) designating a reading start position of the video data stored in the primary storage means. , F) recording the video data stored in the primary storage means from the read start position to the secondary storage means in response to the recording instruction input, whereby the object is achieved. .

The disk device of the present invention comprises: video input means for inputting video data; storage means for temporarily storing the video data in a ring; instruction input means for inputting a recording instruction; Accordingly, a control means for recording video data on the disk-type recording medium retroactively for a certain period of time after the disk-type recording medium rotates and becomes recordable is provided.

[0023] The video input means may include a compression means for compressing video data. The control unit includes a start-up time measuring unit that measures a time from when the recording instruction is input to when the secondary storage unit is completely started up, and a pre-recording time setting unit that sets a time that goes back from the input time of the recording instruction. Transfer rate input means for inputting a transfer rate of the video data; start of determining a video data read start position of the primary storage means from the activation time measuring means, the pre-recording time setting means, and the transfer rate input means; Position determining means.

The control means includes a start time input means for inputting a provisional time from the input of the recording instruction to the completion of the start of the secondary storage means, and a pre-recording for setting a time going back from the input of the recording instruction. Time setting means, transfer rate input means for inputting a transfer rate of the video data,
The image processing apparatus may further include a start position determining unit that determines a start position of reading the video data from the primary storage unit from the start time input unit, the pre-recording time setting unit, and the transfer rate input unit.

The capacity of the primary storage means is such that the video data is stored within a time obtained by adding the pre-recording time set by the pre-recording time setting means and the starting time measured by the starting time measuring means. You may comprise so that it may become larger than the amount transferred to a storage means.

In another disk apparatus of the present invention, a video input means for inputting video data, a storage means for storing the video data, and a free space required for storing the video data are stored in the storage means. It is determined whether or not there is, and if the free space is available, the video data is stored in the storage means. If the free capacity is insufficient, the oldest video data among the video data stored in the storage means is determined. Control means for securing the free space and storing the video data in the secured free space by releasing the object, an instruction input means for inputting a recording instruction, and the recording input from the instruction input means It has a configuration of recording means for recording the video data stored in the storage means in response to an instruction.

[0027] The video input means may include a compression means for compressing video data.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a real-time video recording apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a real-time video recording apparatus according to the first embodiment of the present invention. In FIG. 1, 1 is a video input unit, 11 is an A / D conversion circuit for converting an input video signal into a digital signal, and 12 is a compression circuit for converting a video signal converted into a digital signal into compressed video data. is there. 2 is a primary storage unit, and 21 is a dual port memory (hereinafter DPR) for temporarily storing video data.
AM), 22 is a write address generation circuit for designating a storage position of video data to be stored, and 23 is a read address generation circuit for designating a storage position of video data to be read. 3 is a hard disk device. Reference numeral 5 denotes an instruction input unit for inputting a recording instruction and transmitting it to the control unit 4. The control unit 4 includes a start-up time measurement circuit 41, a pre-recording time setting unit 42, a transfer rate setting unit 43, and a start position determination circuit 44. The start-up time measuring circuit 41 issues a start-up command to the hard disk device 3 in accordance with the input of the recording instruction from the instruction input unit 5, and measures the time until the hard disk device 3 is completely started. The start position determination circuit 44 calculates and reads the read start address of the DPRAM 21 based on the pre-recording time from the pre-recording time setting unit 42, the transfer rate from the transfer rate setting unit 43, and the starting time from the starting time measuring circuit 41. At the same time as notifying the address generation circuit 23, it instructs the hard disk device 3 to start recording.

FIG. 2 shows the relationship between the time that the real-time video recording apparatus according to the first embodiment of the present invention records when recording the video data stored in the DPRAM 21, the recording instruction input time, and the start completion time of the hard disk drive 3. It is shown.

FIG. 3 shows the relationship between the read position of the video data read from the DPRAM 21 of the real-time video recording apparatus and the storage position at the time of the start-up completion in the first embodiment of the present invention.

The operation of the real-time video recording apparatus configured as described above will be described below with reference to FIGS. 1, 2 and 3.

First, a normal operation before a recording instruction is input will be described. When the video signal is input to the A / D conversion circuit 11, it is converted into a digital signal. The video signal converted into a digital signal is compressed by the compression circuit 12.
The compressed video data is stored in the DPRAM 21.
The storage position on the DPRAM 21 is specified by an address generated from the write address generation circuit 22. The write address generation circuit 23 sequentially increments from the start address of the DPRAM 21 and generates the start address again when reaching the end address.
M21 has a ring-shaped structure. Therefore, when the video data corresponding to the capacity of the DPRAM 21 is stored, the once stored video data is periodically overwritten and recorded in order from the oldest video data.

Next, the operation when a recording instruction is input will be described. DPRAM2 until recording instruction is input
1 stores video data while being periodically overwritten and recorded. When a recording instruction is input to the instruction input unit 5, the activation time measuring circuit 41 activates the hard disk device 3 and measures the time until the activation is completed. Startup time measurement circuit 4
Reference numeral 1 denotes a time required until the hard disk drive 3 is started up, that is, the start time is determined by the start position determination circuit 4.
Tell 4 In the pre-recording time setting section 42, a time (FIG. 2) that precedes the time when the recording instruction is input and a pre-recording time are set from outside. The video signal is input to the video input unit 1, compressed into video data, and transferred to the transfer rate setting unit 43.
The speed and transfer rate stored in the RAM 21 are set externally. The start position determination circuit 44 receives the start time, the pre-recording time, and the transfer rate. The start position determination circuit 44 calculates the time going back from the start time and the pre-recording time by using the following equation (FIG. 2).

Z = X + Y (1) In equation (1), Z is a retroactive time, X is a pre-recording time, Y
Indicates startup time.

The start position determination circuit 44 calculates the amount of video data accumulated within the time calculated by the equation (1) and the time calculated from the transfer rate by using the following equation.

M = Z * TS (2) In equation (2), M indicates the amount of accumulated video data, and TS indicates the transfer rate.

Further, the start position determination circuit 44 calculates the video data in the DPRAM 21 from the accumulated video data amount calculated by the following equation (2) and the current write address input from the write address generation circuit 22. And a read start address is calculated (FIG. 3).

RA = WA-M (3) In Expression (3), RA indicates a read start address, and WA indicates a current write address.

After calculating the read start address, the start position determining circuit 44 transmits the read start address to the read address generating circuit 23, and at the same time, issues a recording start command to the hard disk device 3 to transfer the video data stored in the DPRAM 21 to the hard disk device. Start recording on 3.

The capacity of the DPRAM 21 is determined within the sum of the pre-recording time and the start-up time.
Is larger than the amount of video data transferred from the controller to the DPRAM 21. Then, the video data transferred to the DPRAM 21 during the activation of the hard disk device 3 does not overwrite the video data stored in the DPRAM 21 during the pre-recording time. An expression satisfying the above condition is shown below.

Ms ≧ (X + Y) * TS (4) In Expression (4), Ms indicates the capacity of the DPRAN 21.
If the start time Y is set to a value obtained by a life test, an environmental test, a vibration test or the like of the hard disk drive 3 or more, no overwriting is performed.

As described above, according to the present embodiment, the video input unit 1 for inputting video data, the primary storage unit 2 for temporarily storing compressed video data in a ring shape, and the primary storage unit 2 A hard disk device 3 for storing video data,
An instruction input unit 5 for inputting a recording instruction, and a control for activating the hard disk device 3 in response to the instruction input unit 5, measuring the time until the start is completed, and instructing the hard disk device 3 to record video data a predetermined time after the start is completed. By providing the storage unit 4, the hard disk device 3 is stopped until immediately before the recording instruction is input, and the primary storage unit goes back to a predetermined time including the time until the hard disk device 3 is completely started in accordance with the input of the recording instruction. 2 can be recorded on the hard disk device 3.

Although the write address generation circuit 22 and the read address generation circuit 23 are provided in the primary storage unit 2 in the first embodiment, they may be provided in the control unit 4.

In the first embodiment, the start-up time measuring circuit 41 measures the time until the hard disk drive 3 starts. However, the start-up time of the hard disk drive 3 varies from 1 second to 1 second depending on each device and use environment. If it is about 2 seconds, the variation of the time going back is judged as an allowable range,
The maximum value of the starting time of the hard disk device 3 according to the specification may be input, and this maximum starting time may be transmitted to the start position determination circuit 44 as the starting time.

Further, in the first embodiment, the control unit 4 is configured by hardware, but may be realized by a programmable microcomputer.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram of a real-time video recording apparatus according to a second embodiment of the present invention. In FIG.
Reference numeral 1 denotes a video input unit, 11 denotes an A / D conversion circuit that converts an input video signal into a digital signal, and 12 denotes a compression circuit that converts a video signal converted into a digital signal into compressed video data. Reference numeral 21 denotes a dual port memory (hereinafter, DPRAM) 21 for temporarily storing video data. 3
Is a hard disk drive. 6 is a command input section,
It comprises a pre-recording time setting section 42 for setting a pre-recording time, an instruction input section 5 for inputting a recording instruction, and a transfer rate setting section 43 for setting a transfer rate, each of which can be set externally. The above is the same as the configuration in FIG.

The difference from FIG. 1 is the microcomputer 7
Is issued to the hard disk device 3 in accordance with the input of the recording instruction, the time until the hard disk device 3 is completely started is measured, the pre-recording time from the pre-recording time setting section 42 and the pre-recording time from the transfer rate setting section 43 are measured. The point is that the process of calculating the read start address of the DPRAM 21 based on the transfer rate and the start time and instructing the hard disk device 3 to start recording is performed by software, and the control of each block is performed through a common bus line for each block.

FIG. 5 is a flowchart showing the flow of processing of the real-time video recording apparatus according to the second embodiment of the present invention.

The operation of the real-time video recording apparatus configured as described above will be described below with reference to FIGS.

First, a normal operation before a recording instruction is input will be described with reference to the flowchart of FIG.

(Step 5001): Video signal is A / D
When input to the conversion circuit 11, it is converted into a digital signal. The video signal converted to a digital signal is supplied to a compression circuit 1
2 compressed.

(Step 5002) Since the microcomputer 7 controls the read / write address of the DPRAM 21, the empty state in the DPRAM 21 can be managed in the RAM area inside the microcomputer 7. In order to store the compressed video data in the DPRAM 21, the microcomputer 7 acquires the free space information of the DPRAM 21 from the internal RAM area.

(Step 5003): It is determined whether or not there is free space based on the free space information of the DPRAM 21. (Step 5005): If there is free space in the DPRAM 21, the generated video data is stored in the free space of the DPRAM 21. Store.

(Step 5004): If there is no free space in the DPRAM 21, the area where the oldest video data among the video data stored in the DPRAM 21 is stored is released.

As described above, the DPRAM 21 can have a ring-shaped structure as in the first embodiment.
When the video data corresponding to the capacity of the RAM 21 is stored, the once stored video data is periodically overwritten and recorded in order from the oldest video data.

Next, the operation when a recording instruction is input will be described with reference to the flowchart of FIG.

(Step 5006): It is determined whether or not a recording instruction has been input to the instruction input unit 5.

(Step 5007): It is determined whether or not the hard disk drive 3 has been started.

(Step 5008): If the hard disk drive 3 has not been started, it is determined whether or not the hard disk drive 3 is being started.

(Step 5009): If the hard disk drive 3 has not been started, the start is indicated.

(Step 5010): The timer in the microcomputer 7 is started. (Step 5011): If the hard disk drive 3 has been started, the timer in the microcomputer 7 is stopped.

(Step 5012): The pre-recording time is input from the pre-recording time setting section 42.

(Step 5013): The start time required until the hard disk device 3 starts is acquired from the timer in the microcomputer 7.

(Step 5014): The time to go back is calculated by using the equation (1) from the input pre-recording time and the starting time.

(Step 5015): The transfer rate is input from the transfer rate setting section 42. (Step 5016): The amount of video data accumulated within the time to go back is calculated using Expression (2) from the time to go back calculated in Expression (1) and the input transfer rate.

(Step 5017): The current write address is obtained from the RAM area in the microcomputer 7.

(Step 5018): The read start address is calculated using the equation (3) from the obtained write address and the amount of video data accumulated within the time calculated from the equation (2).

(Step 5019): At the same time, the read start address is transmitted to the DPRAM 21 and a recording start command is issued to the hard disk device 3 to start recording the video data stored in the DPRAM 21 on the hard disk device 3.

(Step 5020): Video data compressed by the compression circuit 12 is generated.

(Step 5021): The video data is DP
The compressed video data is stored in the free space generated by storing the data from the RAM 21 to the hard disk device 3.

(Step 5022): If the recording instruction has been completed, the recording to the hard disk device 3 is completed.

As described above, the microcomputer 7 is connected to the video input unit 1, the DPRAM 21, and the hard disk device 3.
By arranging them on the bus line connected to the command input unit 6 and the command input unit 6, real-time recording can be easily performed using a program.

In the second embodiment, steps 5012 and 5015 are executed after step 5011. However, they may be executed before 5006.

Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a block diagram of a hard disk drive showing a third embodiment of the present invention. In FIG.
Reference numeral 1 denotes a video input unit, 11 denotes an A / D conversion circuit that converts an input video signal into a digital signal, and 12 denotes a compression circuit that converts a video signal converted into a digital signal into compressed video data. 2 is a primary storage unit, and 21 is a dual port memory (hereinafter referred to as DPRA) for temporarily storing video data.
In M), reference numeral 22 denotes a write address generation circuit for storing an address of video data to be stored, and reference numeral 23 denotes a read address generation circuit for storing an address of video data to be read. Reference numeral 5 denotes an instruction input unit for inputting a recording instruction and transmitting it to the control unit 4. The control unit 4 includes a start-up time measurement circuit 41, a pre-recording time setting unit 42, a transfer rate setting unit 43, and a start position determination circuit 44. The above is the same as the configuration in FIG.

The difference from FIG. 1 is that the magnetic head 31, actuator 32, recording medium 33, recording / reproducing circuit 34, servo circuit 35, spindle control circuit 36, modulation circuit 37
Is connected to the primary storage unit 2, and the control unit 4 controls the servo circuit 35,
The point is that the spindle control circuit 36 is controlled.

The operation of the hard disk device configured as described above will be described below.

First, a normal operation before a recording instruction is input will be described. When the video signal is input to the A / D conversion circuit 11, it is converted into a digital signal. The video signal converted into a digital signal is compressed by the compression circuit 12.
The compressed video data is stored in the DPRAM 21.
The storage position on the DPRAM 21 is specified by an address generated from the write address generation circuit 22. The write address generation circuit 23 sequentially increments from the start address of the DPRAM 21 and generates the start address again when reaching the end address.
M21 has a ring-shaped structure. Therefore, when the video data corresponding to the capacity of the DPRAM 21 is stored, the once stored video data is periodically overwritten and recorded in order from the oldest video data.

Next, the operation when a recording instruction is input will be described. DPRAM2 until the recording instruction is input
1 stores video data while being periodically overwritten and recorded. When a recording instruction is input to the instruction input unit 5 from the outside of the hard disk drive in a command format, the activation time measuring circuit 41 activates the servo circuit 35 and the spindle control circuit 36 and measures the time until the activation is completed. The start-up time measuring circuit 41 is notified by the servo circuit 35 that the actuator 32 has been moved to the predetermined position, and is notified by the spindle control circuit 36 that the recording medium 33 has reached the predetermined number of revolutions. The start time is transmitted to the start position determination circuit 44. In the pre-recording time setting section 42, a time that precedes the point at which the recording instruction is input and a pre-recording time are set from outside. The video signal is supplied to the transfer rate setting section 43 by the video input section 1.
The speed and transfer rate which are input to the CPU and are stored in the DPRAM 21 after being compressed into video data are externally set. The pre-recording time and the transfer rate are input from the outside in the form of a command in the same manner as the recording instruction, and transmitted to the control unit 4. The start time, the pre-recording time, and the transfer rate are input to the time start position determination circuit 44. The start position determination circuit 44 calculates the time to go back, the amount of video data accumulated during the time to go back, and the read start address by using equations (1), (2), and (3). After calculating the read start address, the start position determination circuit 44 transmits the read start address to the read address generation circuit 23 and simultaneously issues a recording start command to the modulation circuit 37 and the recording / reproducing circuit.
The video data stored in the DPRAM 21 is stored in the recording medium 33.
Start recording.

As described above, according to the present embodiment, the video input unit 1 for inputting video data, the primary storage unit 2 for temporarily storing compressed video data in a ring shape, and a recording instruction are input. An instruction input unit 5 and a control unit that measures the time until the recording medium 33 reaches a predetermined number of rotations in response to the instruction input unit 5 and the actuator 32 completes the movement, and instructs the recording of the video data retroactively from the completion of the activation for a predetermined time. 4, the rotation of the recording medium 33 and the actuator 32 are evacuated until immediately before the input of the recording instruction, and the time until the recording medium 33 and the actuator 32 are activated according to the input of the recording instruction and the activation is completed is included. DPR retroactively at a given time
Since a hard disk device capable of recording video data stored in the AM 21 on the recording medium 33 can be provided, there is no need to newly provide the primary storage unit 2 or the control unit 4 such as a semiconductor memory outside the hard disk device. Thus, an easy real-time recording apparatus can be configured.

Although the write address generation circuit 22 and the read address generation circuit 23 are provided in the primary storage unit 2 in the third embodiment, they may be provided in the control unit 4.

In the third embodiment, the start-up time measuring circuit 41 measures the time from when the recording medium 33 reaches a predetermined number of rotations to when the actuator 32 completes its movement. The start time may be transmitted to the start position determination circuit 44 as the start time.

Further, the control unit 4 is configured by hardware in the first embodiment, but may be realized by a programmable microcomputer.

Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram of a hard disk drive showing a fourth embodiment of the present invention. In FIG.
Reference numeral 1 denotes a video input unit, 11 denotes an A / D conversion circuit that converts an input video signal into a digital signal, and 12 denotes a compression circuit that compresses a video signal converted into a digital signal. 2
Is a primary storage unit, 21 is a dual port memory (hereinafter referred to as DPRAM) for temporarily storing video data, 22 is a write address generation circuit for specifying a storage location of video data to be stored, and 23 is a storage location of video data to be read. Read address generating circuit. Reference numeral 5 denotes an instruction input unit for inputting a recording instruction and transmitting it to the control unit 4. Upon input of the recording instruction, the control unit 4 records the video data of the DPRAM 21 on the recording medium 33 via the modulation circuit 37, the recording / reproducing circuit 34, and the magnetic head 31. The above is the same as the configuration in FIG.

The difference from FIG. 6 is that the control unit 4 does not include the startup time measurement circuit 41.

The operation of the hard disk device configured as described above will be described below.

Since the normal operation before the recording instruction is input is the same as that of the third embodiment, the operation when the recording instruction is input will be described. Until the recording instruction is input, the video data is accumulated in the DPRAM 21 while being periodically overwritten and recorded. In the pre-recording time setting section 42, a recording time and a pre-recording time retroactively from the time when the recording instruction is input are set from outside. Transfer rate setting unit 43
The speed and transfer rate at which a video signal is input to the video input unit 1, compressed into video data, and stored in the DPRAM 21 are set from outside. When the recording instruction is input to the instruction input unit 5, the start position determination circuit 44 determines the time to go back using the formula (1), (2), and (3) from the pre-recording time and the transfer rate, and within the time to go back. The amount of accumulated video data and the read start address are calculated. Start position determination circuit 44
Calculates the read start address, transmits the read start address to the read address generating circuit 23, and at the same time, issues a recording start instruction to the modulation circuit 37 and the recording / reproducing circuit, and records the video data stored in the DPRAM 21 on the recording medium 33. Begin to. The recording position on the recording medium 33 is determined by the control unit 4 managing the logical address.

As described above, according to this embodiment, the video input unit 1 for inputting video data, the primary storage unit 2 for temporarily storing compressed video data in a ring shape, and a recording instruction are input. By providing an instruction input unit 5 and a control unit 4 for instructing recording of video data retroactively for a certain period of time in accordance with the recording instruction input unit 5, the primary storage unit 2 such as a semiconductor memory or the like can be newly provided outside the hard disk device. Since a microcomputer that manages the logical address is unnecessary, a real-time recording apparatus that is inexpensive and does not burden external circuits can be configured.

Although the write address generation circuit 22 and the read address generation circuit 23 are provided in the primary storage unit 2 in the fourth embodiment, they may be provided in the control unit 4.

In the fourth embodiment, the starting time measuring circuit 41 measures the time from when the recording medium 33 reaches a predetermined number of rotations to when the actuator 32 completes its movement. The start time may be transmitted to the start position determination circuit 44 as the start time.

In the fourth embodiment, the control unit 4 is configured by hardware, but may be realized by a programmable microcomputer.

In the first, second, third and fourth embodiments, the secondary storage means is constituted by a hard disk device. However, a disk type recording device such as an optical disk or a magneto-optical disk device or a tape type recording device such as a VTR is used. It may be realized by a recording device.

[0093]

As described above, according to the present invention, the primary storage means for temporarily storing the video data, the secondary storage means for recording the video data stored in the primary storage means, and the secondary storage in response to the recording instruction input By providing the control means for activating the means and recording the video data in the secondary storage means for a certain period of time after the completion of the activation, the secondary storage means can be stopped until immediately before the recording instruction input is input.

[Brief description of the drawings]

FIG. 1 is a block diagram of a real-time video recording device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship among a retroactive time, a recording instruction input time, and a start completion time in Embodiment 1 of the present invention.

FIG. 3 is a diagram showing a relationship between a read position of the DPRAM 21 and a storage position at the time of completion of startup in the first embodiment of the present invention.

FIG. 4 is a block diagram of a real-time video recording device according to a second embodiment of the present invention.

FIG. 5 is a flowchart illustrating processing of a real-time video recording device according to a second embodiment of the present invention.

FIG. 6 is a block diagram of a hard disk device according to a third embodiment of the present invention.

FIG. 7 is a block diagram of a hard disk device according to a fourth embodiment of the present invention.

FIG. 8 is a block diagram of a conventional monitoring image recording apparatus.

FIG. 9 is a block diagram of a conventional real-time video recording device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image input part 2 Primary storage part 3 Hard disk drive 4 Control part 5 Instruction input part 6 Command input part 7 Microcomputer 101 Camera 103 Monitor 105 Sensor 121 A / D conversion part 122 Image signal switching circuit 123 VRAM 124 Compressor 125 First Switch 126 second switch 127 recording memory 128 pre-recording memory 129 control unit 130 timer 131 D / A conversion unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G08B 13/196 G08B 13/196

Claims (13)

[Claims] 1. An image input means for inputting image data, a primary storage means for temporarily storing the image data in a ring shape, a secondary storage means for storing image data of the primary storage means, and a recording instruction Instruction input means for inputting the recording instruction input, and control means for activating the secondary storage means in response to the recording instruction input and recording video data in the secondary storage means retroactively for a certain period of time from the completion of activation. Real-time video recording device. 2. A real-time video recording apparatus according to claim 1, wherein said video input means includes a compression means for compressing video data. 3. The control means sets start-up time measuring means for measuring the time from the input of the recording instruction to the completion of the activation of the secondary storage means, and sets a time retroactive from the input of the recording instruction. Pre-recording time setting means, transfer rate input means for inputting a transfer rate of the video data,
2. The apparatus according to claim 1, further comprising: a start position determining unit configured to determine a start position of reading the video data from the primary storage unit based on the start time measuring unit, the pre-recording time setting unit, and the transfer rate input unit. Time video recorder. 4. The start time input means for inputting a provisional time from the input time of the recording instruction to the completion of the start of the secondary storage means, and the time set from the input time of the recording instruction. Pre-recording time setting means, transfer rate input means for inputting a transfer rate of the video data,
2. The apparatus according to claim 1, further comprising: a start position determining unit configured to determine a start position of video data reading from the primary storage unit based on the start time input unit, the pre-recording time setting unit, and the transfer rate input unit. Time video recorder. 5. The capacity of the primary storage means is such that the video data is stored within a time obtained by adding a pre-recording time set by the pre-recording time setting means and a starting time measured by the starting time measuring means. 2. The real-time video recording device according to claim 1, wherein the amount is larger than the amount transferred to said primary storage means. 6. A real-time video recording apparatus comprising: a primary storage means for temporarily storing video data in a ring shape; and a secondary storage means for storing video data of the primary storage means, wherein: And b) determining whether there is free space required for storing the video data in the primary storage means, and if there is free space, the video data is stored in the primary storage means. When the free space is insufficient, the oldest one of the video data stored in the primary storage is released to secure the free space and secure the video data. C) inputting a recording instruction; and d) determining whether or not the secondary storage means has been started in response to the input of the recording instruction. Activating the secondary storage means if not activated; e) specifying a read start position of the video data stored in the primary storage means; f) responding to the recording instruction input Recording the video data stored in the primary storage means from the read start position to the secondary storage means. 7. An image input means for inputting image data, a primary storage means for temporarily storing the image data in a ring shape, an instruction input means for inputting a recording instruction, and a disk type in response to the recording instruction input. A disk device comprising: control means for recording video data on the disk-type recording medium retroactively for a predetermined period of time after the recording medium rotates and becomes recordable. 8. The disk device according to claim 7, wherein said video input means has a built-in compression means for compressing video data. 9. The control means sets start-up time measuring means for measuring the time from the input of the recording instruction to the completion of the activation of the secondary storage means, and sets a time going back from the input of the recording instruction. Pre-recording time setting means, transfer rate input means for inputting a transfer rate of the video data,
8. The disk according to claim 7, further comprising: a start position determining unit that determines a start position of reading the video data from the primary storage unit from the start time measuring unit, the pre-recording time setting unit, and the transfer rate input unit. apparatus. 10. The control means sets start-up time input means for inputting a provisional time from when the recording instruction is input to when the secondary storage means completes the start-up, and sets a time retroactive from the input time of the recording instruction. Pre-recording time setting means; transfer rate input means for inputting a transfer rate of the video data; start-up of video data from the primary storage means from the starting time input means, the pre-recording time setting means and the transfer rate input means 8. The disk device according to claim 7, further comprising a start position determining means for determining a position. 11. The capacity of said primary storage means is such that said video data is stored within a time obtained by adding a pre-recording time set by said pre-recording time setting means and a starting time measured by said starting time measuring means. 8. The disk device according to claim 7, wherein the amount is larger than the amount transferred to said primary storage means. 12. Video input means for inputting video data,
Storing means for storing the video data, and determining whether or not there is free space required for storing the video data in the storage means; When the free space is insufficient, the oldest one of the video data stored in the storing means is released, so that the free space is secured and the video data is secured. Control means for storing in the free space; instruction input means for inputting a recording instruction; and recording means for recording video data stored in the storage means in response to the recording instruction input from the instruction input means. A disk device, comprising: 13. A disk drive according to claim 10, wherein said video input means has built-in compression means for compressing video data.