JP2009273100A - Set-top box with television linked power supply function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply a set-top box that reduces standby power. <P>SOLUTION: In a set-top box 1 for transmitting a received video-audio signal to an external television receiver 15, the time of television standby mode is determined by a current measuring section 11 for measuring a current to be supplied to the television and a current setting section 12 for setting a threshold of the measured current, and power supply switching is performed. At the same time, the measured current of the current measuring section is utilized as a charging current for complementing discharge of a backup power source section 9 during the standby mode, thereby reducing internal power consumption. Furthermore, as a charging method for complementing discharge of the backup power source section, an intermittent charging system using the measured current of the current measuring section is adopted, thereby further reducing standby power. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a set top box for transmitting a video / audio signal converted by a terrestrial digital tuner and a video / audio decoding unit to a television receiver.

Conventionally, the TV power source and the set-top box power source are individually distributed from an AC outlet or the like, and standby power reduction control is performed independently on the TV side and the set-top box side. Further, the power supply for the set top box simply receives the rectified power from the AC adapter at the DC power supply and is supplied to the controller.

As for the technology for reducing standby power, for example, according to Patent Document 1, a microcomputer stores electric power in a charge storage means such as a secondary battery or an electric double layer capacitor without always operating an AC-DC converter. A power supply circuit for supplying power to the infrared light receiving circuit is also shown. Here, before the voltage of these charge storage means falls below a predetermined value, specifically, below the minimum operating voltage of the microcomputer and the infrared light receiving circuit, the AC-DC converter is operated to charge the charge storage means. More specifically, by stopping charging before reaching the maximum operating voltage of the microcomputer and infrared light receiving circuit, the frequency of operation of the AC-DC converter is reduced, and the AC-DC converter with the lowest power efficiency is used. By reducing power, overall standby power consumption is reduced.

According to Patent Document 2, standby power is supplied to a necessary circuit unit when an electrical device shifts to a standby mode. In this case, a means for monitoring the output of the backup charging power supply is provided in the system control circuit, and when the output of the backup charging power supply becomes insufficient in the standby mode, the standby power is switched from the AC / DC conversion circuit by switching the switch. Is output. Further, the standby power reduction is shown by shifting to the second standby mode that consumes less power than the standby mode after a predetermined period of time using a timer from the time when the standby power is further shifted.
JP 2000-184716 A JP 2006-352963 A

However, because the TV power supply and the set-top box power supply are independent, the standby power reduction control on the TV side is performed in the so-called standby mode when the TV is not used, but the standby mode is set on the set-top box side. The video / audio signal cannot be detected and the normal control is performed as it is transmitted, so that a very wasteful power consumption occurs. As a result, it was not preferable from the viewpoint of protecting the global environment.

In addition, standby power reduction control on the set-top box side simply stops transmission of video and audio signals, and no special power reduction measures have been taken for the rectified power supply of the AC adapter and the internal DC power supply. Also, standby power reduction is insufficient, and wasteful power consumption occurs as described above.

As for standby power reduction control, electric and electronic devices such as televisions are provided with the charge storage means of Patent Document 1 and the backup charging power supply as described in Patent Document 2, and when a predetermined voltage is lowered by voltage monitoring. Shows a method of returning to the AC-DC conversion circuit, a method of shifting to the second standby mode, that is, stopping the power supply to the circuit unit when a predetermined time period has elapsed after shifting to the standby mode, etc. There is no indication that continuous use is ensured while securing a charging current for replenishing the backup power supply in the standby mode, from the charge storage means or the backup power supply to another power supply. Since the charging current for replenishing the backup power source is not ensured, the standby power reduction control is not sufficiently continued.

In order to solve the above-mentioned problem, the present invention performs detection in the standby mode on the TV side by constantly measuring the supply current of the TV power supply on the set top box side, on both the TV side and the set top box side. By using the measured current from the external TV power supply as the charging current for replenishing the discharge, so that the standby power reduction control can be performed at the same time and the standby power reduction control of the backup power supply unit is continued. An object of the present invention is to enable continuous use of a backup power supply unit and, as a result, to supply a set top box with low standby power by standby power reduction control on the set top box side.

In order to achieve the above object, the present invention includes a current measurement unit that measures a supply current of a television power supply and a current setting unit that sets a threshold value of the measurement current, and compares and determines the measured current value and the threshold value. By providing a control unit that detects when the TV is not used, that is, when in the standby mode, standby power reduction control can be performed simultaneously on both the TV side and the set-top box side.

In order to reduce standby power in the standby mode, a power switch unit and a backup power source unit for switching the power source are provided. When the television is used, the DC power source unit is normally driven to the control unit, and in the standby mode, the DC power unit is switched on. Switching from the power supply unit performs backup drive to the control unit by discharging the backup power supply unit.

In the charging current switching unit for switching the charging current, the backup power supply unit is charged completely using the charging current of the normal DC power supply unit when using the TV, and the backup power supply unit is charged in the standby mode. The backup drive is performed by discharging, and the charging is switched to charging using the measurement current of the current measuring unit for replenishing the discharge.

In addition, charging for supplementary discharge of the backup power supply unit in standby mode further reduces standby power by performing intermittent charging control of the measured current of the current measurement unit, and a backup power supply drop detection unit is provided. When a backup power supply drop is detected, overcharge of the backup power supply unit is prevented by switching from intermittent charge to continuous charge.

According to the first aspect of the present invention, the television power supply is performed from the set top box side, the supplied current is constantly measured, and the measured current value is compared with the threshold value by the current setting unit to determine the television standby mode. Time can be determined. Furthermore, switching from normal drive by DC power supply unit to backup drive in standby mode as drive power supply for control unit, and use of measurement current of current measurement unit and intermittent charge control for charging backup power supply unit and backup power supply drop Standby power reduction control can be performed in conjunction with the television side by detection control or the like.

According to the second aspect of the present invention, the control unit performs a comparison determination between the measured current value of the television power supply in the current measuring unit and the threshold value in the current setting unit. When the measured current is greater than or equal to the threshold value, it is determined that the TV is in use, and when it is less than the threshold value, it is possible to perform standby power reduction control simultaneously on both the TV side and the set-top box side by determining the standby mode. It can contribute to reducing wasteful power consumption and protecting the global environment.

According to the third aspect of the present invention, as a power source drive to the control unit, a normal drive by a DC power source is performed when using a television, and a backup is performed by discharging the backup power source unit without using the DC power source unit in a standby mode. In addition to switching to drive, the backup power supply unit is charged by using the normal DC power supply unit charging current when using the TV, and in the standby mode the internal power is obtained by using the current measurement unit measurement current. Consumption can be reduced and standby power reduction can be continued.

According to the invention described in claim 4 of the present invention, the charging for replenishing the backup power supply unit is performed by performing intermittent charge control of the measurement current of the current measurement unit to further reduce standby power and detecting a backup power supply drop. In such a case, overdischarge can be prevented by switching to continuous charging.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2, and 3. 1 is a block diagram of the present invention, FIG. 2 is a conventional block diagram, and FIG. 3 is a comparative diagram of intermittent charge control and continuous charge control.

In FIG. 1, the radio wave received by the antenna 2 is converted by the terrestrial digital tuner unit 3 and the video / audio decoding unit 4 and transmitted to the television receiver 15 as a video / audio signal. This is the basic function of the set top box, and the function is the same in FIG.

In FIG. 1, television power is supplied from the set top box side to the television receiver 15 via the power plug unit 14. At the same time, the supplied current is constantly measured by the current transformer 13 and the current measuring unit 11, and the measured current value is sent to the control unit 5. The threshold value of the measured current set by the current setting unit 12 is also sent to the control unit 5 in the same manner. Since the current transformer 13 measures alternating current, it can perform one-phase measurement or two-phase measurement, but the present invention does not limit the measurement of any number of phases. In addition, as for the threshold value of the current setting unit, there are cases where not only one threshold value but two threshold values are used in order to give a width of hysteresis in order to prevent hunting in consideration of fluctuations in measurement current, etc. The selection of any threshold value is not limited.

In the control unit 5 according to claim 2, the measured current value and the threshold value are compared to determine the television standby mode. Since the determination area is two areas in the case of one threshold value, the determination method is that when the measured current value is equal to or greater than the threshold value, it is determined that the television is being used. On the other hand, when the measured current value is less than the threshold value, the television is not used. At the time of so-called standby mode. Based on the above determination, it is possible to detect the standby mode on the television side on the set top box side. As a result, standby power reduction control can be performed simultaneously on both the set top box side and the television side.

In the case of two thresholds, there are three areas between the upper threshold and the lower threshold. If the threshold is greater than or equal to the upper threshold, it is determined that the television is in use, and if the threshold is less than the lower threshold, the standby mode is determined when the television is not used. For the intermediate region that is less than the upper threshold and greater than or equal to the lower threshold, it is possible to give a range of hysteresis to prevent hunting by the method of continuing the current determination.

In the control unit 5, the control on the set top box side in the TV standby mode is only to hold and continue the standby mode determination and to switch the backup power source unit 9. (1) Video / audio conversion and signal output As a matter of course, the power consumption can be greatly reduced in proportion to the frequency drop by implementing (2) remote control control item restrictions, (3) drastic reduction in microcomputer control frequency in the control unit, and the like. As an embodiment of the present invention, when the microcomputer frequency at normal time is set to 10 MHz, it can be reduced to 32 KHz in the standby mode. ing.

Next, the operation of the power switch unit 10 according to claim 3 will be described. The power switch unit 10 receives a determination command from the control unit 5 and switches between normal driving by the DC power source unit 7 and backup driving by the backup power source unit 9 as the driving power source of the control unit 5. When the television is used, normal driving using the DC power supply unit 7 is performed, and in the standby mode, the input of the DC power supply unit 7 is stopped, and the backup driving by using the discharge of the backup power supply unit 9 is switched.

By using the power reduction control of the control unit 5 and the discharge of the backup power supply unit, it is possible to reduce internal power consumption and standby power.

Next, the operation of the charging current switching unit 8 will be described. The charging current switching unit 8 switches the charging current of the backup power source unit 9 in response to a mode switching command from the power switch unit 10. When the TV is used, the backup power supply unit 9 is fully charged using the charging current of the DC power supply unit 7, and in the standby mode, the measurement current of the current measurement unit 11 is switched instead of the charging current of the DC power supply unit 7. The backup power supply unit 9 is charged to replenish the discharge. The measured current of the current measuring unit 11 is a charging current sufficient for supplementing the discharge of the backup power supply unit 9 although the measured current is reduced compared to when the television is used because the television side is in the standby mode. The reason for this is that, as an embodiment of the present invention, the backup power supply unit 9 is fully charged in about 2 hours when the television is used, and the discharge maintenance time in the backup power supply unit 9 in the standby mode can be secured for about one week. It has been confirmed at the experimental level.

As another operation of the control unit 5 according to the fourth aspect of the present invention, charging control for replenishing the backup power supply unit 9 will be described. Charging of the backup power supply unit 9 in the standby mode uses the measured current of the current measuring unit 11, but it is possible to further reduce power consumption by intermittent charging control instead of continuous charging. As shown in FIG. 3, the continuous charge control performs continuous charge continuously, but the intermittent charge control performs intermittent charge for a charge time t at a fixed time T cycle. As an embodiment of the present invention, it has been confirmed at an experimental level that a sufficient discharge replenishment is possible with a charging time and a cycle ratio of about t: T = 1: 10. It does not limit etc.

Further, in order to prevent over-discharge of the backup power supply unit 9 while the intermittent charge control is continued, the backup power supply unit lowering detection unit 6 is provided and the lowering threshold value is sent to the control unit 5. The control unit 5 compares the DC voltage value of the backup power supply unit 9 with a decrease threshold value, and when the DC voltage value is less than the decrease threshold value, forcibly switches to continuous charge control. As a result, it is possible to prevent over-discharge of the backup power supply unit 9 in the unlikely event.

  1 shows a block diagram of the present invention.   A conventional block diagram is shown.   The comparison figure of intermittent charge control and continuous charge control is shown.

Explanation of symbols

1. Set top box
2. antenna
3. Terrestrial digital tuner
4). Video / audio decoding unit
5. Control unit
6). Backup power drop detector
7). DC power supply
8). Charging current switching part
9. Backup power supply
10. Power switch
11. Current measurement unit
12 Current setting section
13. Current transformer
14 Power plug
15. TV receiver
16. AC adapter

Claims (4)

In a set-top box that converts radio waves received by an antenna into video / audio signals by a digital terrestrial tuner unit and a video / audio decoding unit, and transmits them to an external television receiver, a power plug-in unit for power supply for the TV is provided, A current measurement unit that measures the supply current, a current setting unit that sets a threshold value of the measurement current, a control unit that compares the measured current value and the threshold value to determine the TV standby mode time and performs standby power reduction control, and A power switch unit that switches power according to a control command; a charging current switching unit that switches a charging current; a DC power unit that performs normal driving of the control unit; and a backup power source unit that performs backup driving in a standby mode; By configuring a backup power supply drop detection unit that performs backup power supply drop detection, a TV that enables standby power reduction control linked to the TV side is enabled. Interlocking power function with a set-top box. In the current measurement unit that measures the supply current of the TV power supply, the current setting unit that sets the threshold value of the measurement current, and the control unit that compares the measured current value and the threshold value to determine the TV standby mode, the measurement current If the value is greater than or equal to the threshold value, it is determined that the TV is in use. On the other hand, if the measured current value is less than the threshold value, the TV standby mode is detected by determining the TV standby mode. The set-top box with a TV interlocking power supply function according to claim 1, wherein standby power reduction control is simultaneously performed in both of the above. In the power switch section for switching the power supply and the charging current switching section for switching the charging current, the DC power supply section is normally driven as the drive power supply for the control section when the TV is used, and the DC power supply section is not used in the standby mode. In addition to switching to backup drive by discharging the backup power supply, the backup power supply is fully charged using the normal DC power supply current when using the TV, and the backup power supply is replenished in standby mode. Therefore, the set-top box with a TV interlocking power supply function according to claim 1, wherein internal current consumption is reduced by using a measurement current of a current measurement unit, and standby power reduction is continued. Charging for replenishing the backup power supply in standby mode is performed by intermittent charge control based on the current measured by the current measurement unit. If a backup power supply drop is detected by the backup power supply drop detection unit, switching to continuous charging is performed. The set-top box with a TV interlocking power supply function according to claim 1, wherein overdischarge is prevented, and standby power reduction is continued.

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