KR20000003197A - Method for maintaining a status before interruption of electric power of a video cassette recorder - Google Patents

Abstract

PURPOSE: A method is provided to continue to operate a video cassette recorder by maintaining an operation state before interruption of electric power. CONSTITUTION: The method for maintaining a status before interruption of power of a video cassette recorder which includes a micom(11) for controlling the operation of the video cassette recorder and a memory(15) for maintaining stored data even after power-off, the method comprises the steps of: periodically storing an operation status of the video cassette recorder to the memory(15) when a power is supplied normally; and after interruption of electric power, operating the video cassette recorder by use of the stored operation status in the memory(15) before the interruption of power when the power is supplied again.

Description

How to maintain the video cassette recorder before power failure

The present invention relates to a method of maintaining a state of power failure even if a sudden power failure occurs in a video cassette recorder (hereinafter referred to as VCR: Video Cassette Recorder), and more particularly, an electrostatic compensation oscillation element or a power failure detection unit for predicting power failure. The present invention relates to a method of maintaining a pre-outage state of a video cassette recorder that maintains an operation state before a power outage when power is applied again without a power supply.

In general, the VCR is equipped with a microcomputer and adds a clock function and a timer function as well as a control function for various operation modes such as automatic channel selection, scheduled recording, and recording / playback.

Fig. 1 is a block diagram showing a microcomputer peripheral circuit of such a VCR, which is a main oscillator X1 used when power is normally supplied to a microcomputer 11 operating by receiving an operating power supply 5V, and when the power is normally supplied. A reset unit 12 connected to the sub oscillator S2 used for power failure compensation and outputting a reset signal to the microcomputer 11 when the operating power 5V of the microcomputer 11 is turned off and then on again; When the operating power supply 5V of the microcomputer 11 falls below a predetermined level (for example, 5V), the electrostatic detection unit outputs a signal (for example, a low level signal) foretelling the blackout to the microcomputer 11 ( 13).

In the above configuration, the operation during power failure is performed in the same procedure as the flowchart shown in FIG. 2, and the microcomputer 11 oscillates the main oscillator X1 to process the control function during normal operation, while the electrostatic detection unit 13 Is read (201), and it is checked whether it is a high level signal (202). Here, the high level output signal of the power failure detection unit 13 is a signal indicating that the operating power supply is in a steady state above a predetermined level (5V), and the low level output signal is when the voltage level of the operating power supply starts to drop due to a power failure. This signal informs you of power failure.

Therefore, while the output of the electrostatic detector 13 is at a high level, the main oscillator X1 is operated to perform a general control operation (207). However, when the output of the electrostatic detector 13 is at a low level, the main oscillator X1 is output. Stop oscillation (203), oscillation compensation sub oscillator (X2) to maintain the basic functions such as the clock function (204), and the output of the electrostatic detection unit 13 is high, i.e. It is checked whether it has returned to the normal state (205), and the operation continues while it is at the low level, and when the output of the electrostatic detection unit 13 reaches a high level due to the power supply being turned on again, the secondary oscillator X2 is stopped and the main power supply residue remains. By oscillating (X1), the control function of normal operation is performed (206, 207).

As such, in the related art, the power failure compensator and the power failure can be foreseen that the power failure is maintained because the basic function such as the clock function is maintained even if the power failure is performed by operating the power failure compensator oscillator before the operation power is turned off. There is a problem that a compensatory oscillator must be provided and simply maintains basic functions such as a clock function in case of power failure, and resets as soon as the power is turned on. Previously, the recording operation was performed. However, in order to continue recording after a power failure of 1 to 2 minutes, the user had to operate the remote controller or the keypad again to operate again.

The present invention has been made in order to solve the above-mentioned conventional problems, the object is to remember the operation state of the power failure before the power failure of the video cassette recorder can continue the operation of the power failure after the power is back on even if the power failure It is to provide a way to maintain state.

1 is a block diagram showing a microcomputer and a peripheral configuration thereof provided in a conventional video cassette recorder.

FIG. 2 is a flowchart showing a conventional processing procedure during power failure by the microcomputer of FIG.

Figure 3 is a flow chart showing a method for maintaining the state before the electrostatic without the oscillation element for the electrostatic compensation according to the present invention, Figure 3a shows the processing procedure when the power is normally applied, Figure 3b when the power is applied again after the power failure Shows the processing procedure of.

Fig. 4 is a block diagram showing a microcomputer and its peripheral configuration of a video cassette recorder to which the method for maintaining an electrostatic state according to the present invention is applied.

* Description of the symbols for the main parts of the drawings *

11 ... Micom

12 ... reset section

13 ... blackout detector

14 ... blackout time detector

15 ... memory (EEPROM)

X1, X2 ... crystal oscillator

As a constitutional means for achieving the above object of the present invention, the present invention maintains the power failure state of a video cassette recorder having a memory in which data stored after the power-off is not erased and a microcomputer for controlling the operation of the video cassette recorder. In the method,

Storing the operation state of the current video cassette recorder in a memory at regular intervals when the power is supplied;

And operating the video cassette recorder according to the operation state of the video cassette recorder before the power failure stored in the memory after the reset when the power is first applied again after the power failure.

According to still another aspect of the present invention, there is provided a memory which does not erase stored data even after a power off, a microcomputer that controls the operation of a video cassette recorder, and an exponential decrease from the applied power level when the power is turned off. In the method for maintaining the pre-outage state of a video cassette recorder having an RC circuit exhibiting a voltage characteristic,

Storing the operation state of the current video cassette recorder in a memory at regular intervals when the power is applied;

Determining whether it is correctable by comparing whether the voltage of the RC circuit is smaller than a predetermined reference voltage after a reset operation at a time when power is again applied after a power failure;

If it is determined that the correction is possible in the determining step, operating the video cassette recorder according to the operation state of the video cassette recorder stored in the memory before power failure; and if it is determined that the correction is impossible, resetting the video cassette recorder to an initial state. It is characterized by.

Hereinafter, with reference to the accompanying drawings will be described in detail the operation of the present invention.

Fig. 3 is a flowchart showing a method of maintaining a state before a power failure without an electrostatic compensation oscillation element according to the present invention in accordance with a processing procedure, and Fig. 3A is a processing procedure performed when a power source before power failure is normally applied. Fig. 3B shows a processing procedure performed at an initial stage in which power is again turned on after a power failure.

Fig. 4 is a block diagram showing the microcomputer peripheral configuration of the VCR to which the method for maintaining the state before the electrostatic without the electrostatic compensation oscillation element according to the present invention shown in Fig. 3 is applied. , The operation mode of the VCR which controls the operation such as recording, scheduled recording, etc. in the memory 15 at regular intervals, and reads the stored operation mode when the power is first turned on, and controls the VCR in the state. 11), a reset signal to the microcomputer 11 when the main oscillator X1 applying the reference clock to the microcomputer 11 and the operating power source 5V applied to the microcomputer 11 are turned off and then on again. The reset unit 12 outputs a signal and is charged by receiving a signal of a predetermined level (for example, 5 V) from the microcomputer 11, and is discharged when the signal is cut off by power-off, so that the voltage decreases exponentially. Power failure time with RC circuit Under the control of chulbu 14, the microcomputer 11 includes a memory 15 for storing an operating state of the VCR to be input at the predetermined time.

Next, a method of maintaining the state before the electrostatic without the electrostatic compensation oscillation element according to the present invention will be described with reference to the flowchart of FIG. 3 and the block diagram of FIG.

First, when the power is normally applied before the power failure, as shown in FIG. 3A, when the power is turned on and the operation is started (311), the operation state of the VCR at a predetermined period T, for example, the recording, scheduled recording setting state, The memory 15 stores the VCR operation state at the corresponding time point, such as playback and rewinding. More specifically, an address for storing the operation state of the VCR is set in the memory 15, and the operation state of the VCR is stored at the address. In other words, data stored at the address is erased every cycle T, and data representing a new operation state at that time is stored. Therefore, the memory 15 always stores the most recent VCR operating state.

In the state where the power is normally applied, the power failure time detection unit 14 receives the power 5V through the microcomputer 11 and is charged in the 5V state.

In the state where the above operation is made, when sudden power failure occurs, the operation power applied to the microcomputer 11 is turned off, the operation of the microcomputer 11 is stopped, and the power supply 5V applied to the power failure time detection unit 14. Is also blocked.

Then, after a predetermined time (for example, within 3 or 4 minutes) has elapsed, the processing as shown in FIG. 3B is performed at the time when the power supply starts again.

That is, when the power is turned on again after power failure (321), the microcomputer 11 receives the reset signal from the reset unit 12 (322), resets to an initial state (323), and then the power failure time detection unit ( The value of the A / D port B to which the voltage value of 14) is input is read (324). Then, it is checked whether the value of the read A / D port B is a correctable value (325). Here, the criterion for determining whether or not correction is possible is that the power failure time detection unit 14 determines that the correction is impossible when there is little change in the voltage level with respect to the discharge time, and when it is not, the correction is possible. The time that can be corrected by the blackout time detector 14 is within a few minutes.

In the comparison judgment, if it is determined that correction is possible, data indicating the operation state before power failure of the VCR stored in the memory 15 before the power failure is read (326), and the VCR is controlled in accordance with the read data to control the state before operation. (327). For example, if the cassette was being played back before the operation, the playback operation is instructed again, and if it is recording, the recording is instructed.

On the contrary, if it is determined that the correction is impossible, the operation mode of the VCR is initialized. For example, it initializes to a standby state that does not perform a function such as playback or recording (328).

Then, the process returns to the normal state and repeatedly executes the process shown in Fig. 3A while performing the general control function.

As described above, the present invention stores the current operation state before the power failure and operates the VCR in the stored operation state at the time when power is again applied after the power failure. There is no need to do this, for example, in the case of regeneration, even if a power failure, the power supply is only when the power supply comes back to operate again, there is an excellent effect to provide more convenience to the user.

In addition, there is an excellent effect that can continue to maintain the state of the electrostatic without having to provide a sub oscillator for the electrostatic compensation.

Claims (2)

In the method of maintaining the state before the power failure of the video cassette recorder having a memory which does not erase the data stored even after the power off and the micro-computer controlling the operation of the video cassette recorder, Storing the operation state of the current video cassette recorder in a memory at regular intervals when the power is applied; Operating the video cassette recorder according to the operation state of the video cassette recorder stored in the memory after the reset, when the power is applied again for the first time after the power failure, before the power failure of the video cassette recorder How to stay. Memory that does not erase stored data after power off, Micom that controls the operation of the video cassette recorder, and RC circuit which exhibits an exponentially decreasing voltage characteristic from the applied power level when the power is turned off. In a method for maintaining a state before power failure of a video cassette recorder, Storing the operation state of the current video cassette recorder in a memory at regular intervals when the power is applied; Determining whether it is correctable by comparing whether the voltage of the RC circuit is smaller than a predetermined reference voltage after a reset operation at a time when power is again applied after a power failure; If it is determined that the correction is possible in the determining step, operating the video cassette recorder according to the operation state of the video cassette recorder before power failure stored in the memory, and determining that it is impossible to correct, and resetting the video cassette recorder to an initial state. A method of maintaining a state before a power failure of a video cassette recorder, characterized in that.