JPH0851608A - Equipment and method for setting clock in video receiver correctly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a correct time by receiving the data component of a television signal expressing present time and setting the present time to be a precise present time including the number of seconds corresponding to it. SOLUTION: This device is provided with a memory 116 storing data expressing a first time value including a number of seconds component, the source of a television signal including a data component and a controller 110 defining a second time value by processing the data component. Then the controller 110 decides a time difference expressing how a first time value is different from a second time value and when the time difference indicates that the first time value is different from the second time value by a prescribed time value, the controller 110 changes the number of seconds component to a first prescribed number of seconds value according to it. Thereby, an internal time is precisely matched with a correct time. Then a display device is displayed by a kinescope 158.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed caption (closed caption) included in a television signal.
n) The present invention relates to a television receiver including a circuit for decoding information.

The description of the present specification is based on the priority of the present application, and is based on British Patent Application No. 94144444 (19).
(Filed on July 18, 1994) and US patent application No. 08/3
No. 62,284 (filed on Dec. 22, 1994), which is based on the description of the specification of the UK and US patent applications by referring to the numbers of the UK and US patent applications. Shall form part of this specification.

[0003]

2. Description of the Related Art Conventionally, keeping an accurate time of day is required for a television or a video cassette recorder (v
It was a problem with the video receiver in the ideo cassette recorder-VCR). Only the knowledge of the user was the basis for programming the current time. However, the typical consumer does not know how to set or correct the internal clock and does not want to do so. As a result, the display of many receivers was unchanged from the default flashing display at "12:00 AM" upon power up.

In the United States, television signals have extended data
By incorporating service (Extended Data Services- EDS) information, the current time information can be obtained by a television signal. The EDS information is the data component of the signal inserted in the vertical blanking interval of the NTSC standard television signal. In particular, EDS data can be inserted in line 21 of field 2 in coded form, such as closed caption data. The EDS and captioning share the band (bandwidth) of the line 21 in the field 2 in a time multiplexed manner. E
From DS, program title, network worm name,
It provides a wide range of useful information, such as the current time.

The format of EDS data is NTSC
It is specified in the EIA-608 standard for line 21 data service of television signals. The EDS data component of a television signal is organized in packets of data bytes. Each packet carries a piece of information, for example the current time. Each line 21 of field 2 contains 2 bytes of EDS data. Each byte consists of 7-bit data (bit 0
To bit 6) and a parity bit (bit 7). For any line 21 in field 2,
The particular data byte value appearing in the first byte indicates the start of the packet. Each "start" data byte also defines a "class" of information contained in the packet. For example, a packet of the "current" class contains information about the current program being displayed. Packets of the "miscellaneows" class contain various types of information, such as time of day information.
For example, if the value of the first data byte on line 21 of field 2 is 01 _h (that is, 01 _hex ), it indicates the start of a "current" class packet, and if the value is 07 _h , it is a "miscellaneous" class. Shows the start of the packet.

The data byte following the "start" byte, that is, the second byte contained when a particular line 21 appears, defines the "type" of information contained in the packet. ing. For example, if you become a value 01 _h of data bytes following the start bytes of "miscellaneous" packets, "type" of the packet is "time (time of day)
It is a packet. The time packet is 6 bytes (start,
In addition to the type and end byte), the format is as shown in Table 1. These 6 bytes define the current time based on GMT. The valid ranges for the various fields are shown in Table 2. In Table 1, the "D" bit of byte 2 defines whether daytime saving time is currently implemented, and the "L" bit of byte 3 defines whether the current year is a leap year. , Byte 4 "Z"
The bit defines whether the current time (in seconds) should be set to zero. In Table 2, when the "day of week" value in byte 5 is 1, it indicates Sunday, and when the value is 7, it indicates Saturday. The "year" value in byte 6 is selected so that the current year is obtained by adding that value to 1990.

[0007]

[Table 1]

[0008]

[Table 2]

Since the time of day is defined by GMT, the information defining the user's time zone is needed to determine the correct local time. The time zone of the source of the video signal is sent in another type of packet in the miscellaneous class of EDS packets, the "local time zone and DST" packet type. The time zone packet consists of 2 bytes. First
In the byte, bits b4 to b0 specify how much time (number of hours in the range 0-23) behind GMT the location of the source of the video signal. Bit b5 of the first byte determines whether the local of the signal source is implementing daylight saving time.
If bit b5 is a logical 0, that is, if daylight savings time is not implemented, then the "D" bit of the time packet is ignored.

Local time zone packets are inserted into the video signal only if reception of the signal is limited to areas within a single time zone. If multiple areas are present on multiple time zone boundaries, the required time zone information is provided when the receiving device is powered on, for example, in the initialization procedure.
Must be entered into the receiving device by the user as a step performed during the menu period.

[0011]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As shown in Table 1, E
The current time included in the DS data is not seconds, but hours (hou
rs) and minutes. The single bit "Z" is for indicating whether the seconds value is zero during EDS transmission. The current time is exactly the beginning of the minute
If (top of a minute) is sent, that is, if the number of seconds is zero, setting the "seconds" bit resets the internal seconds clock of the receiving device to zero. You can tell that. But,
There are at least two problems with sending time information using the "seconds" bit. The first problem is that time packets are only occasionally sent (eg, once every 10 minutes) and randomly. In this case, a long time interval may be required before sending the time information with the seconds value set to zero. The second problem is that the "zero seconds" bit may not be set, even if it is exactly at the beginning of the minute. When that happens, the receiving device does not have the exact right time. The correct time is important when controlling features, including the seconds component, such as starting recording a television program (program) on a video cassette recorder (VCR). There is. Inaccuracies in the seconds component can cause the recording to start too early (part of the unwanted program is recorded) or too late (the beginning of the required program is not recorded).

[0012]

SUMMARY OF THE INVENTION The present invention aims to identify the above-mentioned problems and to provide a solution to the problems. According to one embodiment of the present invention, a television receiver including a closed caption signal decoder,
Upon receipt of a data component of a television signal representing the current time, such as Extended Data Services (EDS) data, the current time stored in the television receiving device is accordingly responsive and correct including the number of seconds. Set to the current time.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to facilitate understanding of the present invention, description will be given below with reference to the accompanying drawings.

FIG. 1 shows a block diagram of a television receiver to which the present invention is applied.

As shown in FIG. 1, a television receiver device receives a radio frequency (RF) signal and applies the signal to a tuner assembly 102.
The F input terminal 100 is provided. The tuner assembly 102 inputs a tuning voltage to the tuner assembly 102 via a wire 103 and a band switching signal via a signal line indicated by a wide double arrow 103 '. Under the control of the (tuner controller) 104, a specific RF signal is selected and amplified.

The tuner assembly 102 receives the received R
The F signal is converted to an intermediate frequency (IF) signal and the IF output signal is converted into a video (VIF) and sound (SIF) amplifier and detector unit.
t) Send to 130. The VIF / SIF amplifier and detector unit 130 amplifies the IF signal input to its input terminal and detects the video and audio information contained therein. The detected video information is applied as one input of the video processor unit 155.
The detected audio signal is the audio processor 1
35, where it is processed, amplified, and then sent to the speaker assembly 136.

The tuner controller 104 is a system control microcomputer.
In response to the control signal input from the controller 110, the tuning voltage and the band switching signal are generated. Although the terms "microcomputer", controller, and "microprocessor" are used herein, they are equivalent. Also, the control functions of the microcomputer 110, as used herein, may be performed by an integrated circuit (ie, "custom chip") specially made for such a particular purpose. The term "controller" is also inclusive of such devices.
The microcomputer 110 is an infrared (Ifrared-I
R) Receives user commands sent from the receiver 122 and from the "local" keyboard 120 on the television receiver itself. I
The R receiver 122 receives the IR transmission from the remote control transmitter 125. The microcomputer 110 is a central processing unit.
cessing unit-CPU) 112 and program memory (R
OM) 114 and stores channel related data in random access memory (RAM) 116.
RAM 116 may be internal or external to microprocessor 110 and may be of either volatile or non-volatile type. The term "RAM" refers to an electrically erasable programmable reprogrammable ROM.
Needless to say, the ad only memory-EEPROM) 117 is also included. As those skilled in the art will appreciate, when using volatile memory, a suitable form of standby power supply is used to preserve the contents of the receiving device when it is turned off. ) Is preferred.

The microcomputer (or controller) 110 generates control signals. The tuner control unit 104 receives the control signal and controls the tuner 102 to select a specific RF signal according to the control signal input by the user from the local keyboard 120 and the infrared (IR) receiver 122. Tuner 1
02 outputs an intermediate frequency (IF) signal, and video IF
(VIF) amplification stage, AFT circuit, video detector,
And the signal to a processing unit 130 which includes an audio IF (SIF) amplification stage. Processing unit 130
Outputs a first baseband composite video signal (TV) and a sound carrier signal. This sound carrier signal is input to an audio signal processor unit 135 with an audio detector. It should be noted that the unit 135 may include a stereo decoder. Audio signal processor unit 135 outputs a first baseband audio signal and provides the signal to speaker unit 136.
The second baseband composite video signal and the second baseband audio signal can be input to the video IN terminal and the audio IN terminal from an external source.

The first and second baseband video signals (TV) are combined with a video processor unit 155 (which comprises a selection circuit (not shown)).
The electrically erasable ROM (EEPROM) 117 is the controller 1
Combined with 10, it is used to store automatic programming channel data and user entered channel data as a non-volatile storage element.

The processed video signal appearing at the output terminal of the video signal processor unit 155 is input to a kinescope driver amplifier (Kine Driver Amplifier) 156,
There, after being amplified, the color picture tube assembly (color p
icture tube assembly) It is displayed by being applied to the electron gun of 158. The processed video signal appearing at the output terminal of the video signal processor unit 155 is a sync separation unit.
It is also input to the (Sync Separator Unit) 160, where the horizontal drive signal and the vertical drive signal are separated and input to the deflection unit 170. The output signal from the deflection unit 170 is a picture tube assembly 158.
Is applied to the deflection coil of, and controls the deflection of the electron beam. The part of FIG. 1 described so far is, for example,
Thomson Computer Electronics, Inc. (Indianapolis, In
RCA CTC-140 color television manufactured by diana).

Next, an embodiment of the present invention will be described with reference to the remaining portion shown in FIG. 1 and the flowchart of FIG. In FIG. 1, the data slicer (DATA SLICER) 145
Is a VIF / SIF amplifier and detector unit 130.
As a first input, and as a second input from the video IN terminal as a video switch (VIDEO SWITCH) 13
Closed caption data is received via 7. This video switch 137 is the controller 110
Under the control of, select the appropriate source of closed caption data. The data slicer 145 decodes the data component of the television signal and outputs the decoded data as closed caption data and EDS data on lines 142 and 1.
To the closed caption OSD processor 140 via 43. The data slicer 145 also sends the closed caption status data to the controller 110 as the NEWDATA and FIELD signals. The FIELD signal indicates whether the received signal is in field 1 or field 2 of the video signal. Extended Data Service (EDS)
If the data is included in the video signal, the ESD data is on line 21 of field 2. Under the control of the controller 110 via the control line 141, the closed caption OSD (on-screen display) processor 140 causes a character (characte).
r) generate a signal and send the signal to the video signal processor 1
It is applied to the input terminal of 55, where it is inserted into the processed video signal.

The system shown in FIG. 1 has a clock mechanism 118.
Also included, which is built into the controller 110,
It is under its control. Clock 118 represents a register or memory location in which the current time information is stored. The controller 110 responds to interrupts at periodic intervals, for example, in response to a 60 Hz signal generated from an AC power source, to the clock 11
The current time data stored in 8 is incremented. This time is a display on the front panel of the television receiver, such as a 7-segment display device (not shown in FIG. 1).
Displayed by device or kinescope 158.
Both types of time displays use controller 1
Controlled by 10. When displaying the time on the kinescope 158, the controller 110 displays the time information,
On-screen display (OSD) processor 1
40 to the video signal processor 155.
As a result, the time information is included in the video signal coupled to the kinescope 158 to provide, for example, a time display superimposed on a normal video image.

The current time of the clock 118 is checked by the controller 110 and corrected if necessary. For example, the controller 110 can correct the current time in response to user-entered time data (eg, from the IR remote 125). Alternatively,
The controller 110 can also adjust the time according to the EDS information extracted from the video signal by the data slicer 145.

While EDS information is useful, EDS data is not included in all television signals. Accessing EDS capabilities requires tuning to the particular channel containing the EDS data.
For example, in the current situation in the United States, Public Broadcasting Service -PB
S) Only the signal from the station contains EDS data. Therefore, to update the time information from the EDS, it is necessary to tune to the PBS station, and the EDS data is processed when the television receiver is normally used and when the PBS station is tuned. Is. However, there is no guarantee that the PBS will be selected, even during normal use of the receiver. Therefore, in the control program of the controller 110, the channel corresponding to PBS is set to the tuner 102.
Includes a routine to automatically select. The PBS channel information may be input by the user from the remote control 125 and stored in the RAM 116 during the initial setup of the television receiver, for example.

In order not to interfere with the normal use of the television receiver, the EDS is automatically tuned only when the television is not in use. That is,
"Operating power" is inactive,
This is when the "standby power" is active. In FIG. 1, both the standby power supply STBY and the operating power supply PWR are obtained from the power supply 180. The standby power source STBY is active as long as the power source 180 is connected to a power source, for example while plugged into an AC power outlet. The operating power supply PWR is active only when it is "powered on", for example, by pressing the appropriate button from the remote control 125. In general, most of the features shown in FIG. 1 are only connected to the operating power supply and work only when the operating power supply is activated. However, in order to automatically tune to the EDS signal source and process EDS data while in the power off state, the controller 1
The mechanism, including 10, tuners 102-104 and data slicer 145, receives standby power and remains active after operating power is turned off. When the controller 110 detects the power-off state, it uses the standby power source to execute the above-described automatic tuning and EDS processing procedure.

The channel that is the source of the EDS data, without relying on the PBS channel information entered by the user, is
It can be identified by "scanning" all active channels. In the system shown in FIG. 1, the channel scan is performed by the controller 1
10 outputs a control signal to the tuner control unit 104, receives this control signal, and
Assembly 102 selects each active channel. When each channel is tuned,
The video signal output from the unit 130 is processed by the data slicer 145 to extract the existing data. The extracted data is tested by controller 110 to determine if the extracted data is EDS data. For example, line 21 of field 2
EDS data code is detected during the period
This means that DS data is present. Once EDS
When a signal is detected, the tuning information of that signal is R
Stored in the AM 116, the channels carrying EDS data are tuned when the controller 110 executes the automatic EDS tuning routine. In order not to interfere with the normal use of the television receiver, the search for the EDS channel can only be performed when the television receiver is in the "power off" state, as mentioned above. Alternatively, some television receivers use E as part of the channel scan used during the initial setup of the receiver.
Locate the DS data source and identify all active channels to identify the channel "scan list (scan li
st) ”can also be created.

When EDS data is received, the system shown in FIG. 1 processes the data under the control of a program executed by controller 110 to generate clock 118.
To maintain the correct time. This program is for example EE
The functions of the program stored in the PROM 117 are shown in the flowchart of FIG. Briefly, when the program is executed, the system determines the time difference between the time value of clock 118 and the time value of the EDS time packet. The time difference value determines how the time value stored in clock 118 is modified to maintain the correct time. In FIG. 2, the current time, expressed in hours, minutes, and seconds, is located, for example, in the controller 110, and "t
Assume they are stored in respective memory locations or registers named od_hours "," tod_minutes ", and" tod_seconds ". Similarly,
The hours and minutes data from the received EDS time data is stored in locations named "eds_hours" and "eds_minutes".

As shown in FIG. 2, when an EDS time packet is received, the routine starts at step 200. In step 210, the EDS time in hours and minutes is subtracted from the current time in hours and minutes stored in the system to obtain "time_differenc".
A value named e "is obtained.
e_difference is evaluated. If time_difference is equal to a positive 1 minute, that is, if the current stored time exceeds the EDS time by 1 minute, the current number of seconds stored, ie tod_seconds, is set to 0 ( Step 230). Also, if time_difference is not equal to positive one minute, then another evaluation is performed at step 240 following step 220 to determine if time_difference is equal to negative one minute. If so, the current time is set to the EDS time in step 250 and the current number of seconds is set to zero. time_differenc
If e is neither a positive one minute nor a negative one minute, step 24
Following 0, step 260 is performed where a third evaluation is made to determine if time_difference is equal to 0. Otherwise (ie time_differe
nce is a value other than 0, +1 minute, or -1 minute), step 260 is followed by step 270, in which the current number of hours and minutes are set to EDS hours and minutes, and tod_seconds is set to 30. Time_diffe if tested in step 260
If rence is equal to 0, the routine is exited at step 280 following steps 230, 250 and 270.

The operation of the system shown in FIG. 2 is summarized as follows.

(1) If internal time ('hours'&'minutes')
Is equal to the EDS time, nothing is done ["YES" at step 260].

(2) If internal time ('hours'&'minutes')
And the EDS time is 2 minutes or more, the internal time ('hours'&'minutes') is set equal to the EDS time and the internal'seconds' time is set to 30 [ "NO" in step 260].

(3) If internal time ('hours'&'minutes')
Is 1 minute behind the EDS time, the internal time ('ho
urs'&'minutes') is set to the EDS time, internal's
econds' time is set to zero [step 240
Then "YES"].

(4) If internal time ('hours'&'minutes')
Is 1 minute ahead of EDS time, internal'second
s'time is set to zero ["YES" at step 220)
].

When the system is first powered up, its internal clock is not set, so operation 2 above (time_difference> 2 minutes, ie "NO" in step 260) received the first EDS time message. Will be done later. As a result, the internal clock is either 0-30 seconds ahead of the correct time or 0-30 seconds behind the correct time. In order for operation 2 to be performed, the time difference between the internal time and the EDS time needs to be 1 minute or more, so that operation 2 is not repeated unless the power supply fails.

Operation 1 (time_difference = 0,
That is, "YES" in step 260 is performed at almost any time. When operation 1 is performed, the internal time coincides with the EDS time up to the fractional resolution, so
It means that there is no information about the time error. As a result, the internal time is considered correct and is not changed.

After the first time adjustment is made, whether the internal time is ahead of or behind the correct time, it is at most 30.
Seconds. If the internal time is later than the correct time, the EDS message is finally received, and the EDS time that is one minute ahead of the internal time is designated therein. For example, if the second value of the correct time is 05, but the second value of the internal time is 55, operation 3 (time_difference = -1 minute, that is, step 240
"YES") is done and the internal time jumps to advance to the start of the next minute. As a result, the error between the correct time and the internal time is reduced. The error is reduced, so the new E
Operation 1 is more likely to be performed each time a DS time message is received. However, since the timing of transmitting the EDS time message is random, finally, the operation 3 is performed a sufficient number of times, so that the internal time exactly matches the correct time.

If, after the initial time adjustment, the internal time is ahead of the exact time, an EDS message will eventually be received where the EDS time is one minute behind the internal time. There is. In this case, operation 4 is performed (time_difference = +1 minute, ie "YES" in step 220) and the internal time jumps back to the start of the current minute. Again, the error is reduced,
Finally, the subsequent EDS message ensures that the internal time exactly matches the correct time.

So far, the invention has been described for the case where EDS data is contained on line 21 of field 2 of an NTSC standard television signal, but the data component containing the time information has been described above. It is also possible to send by another method. For example, the data components can be included in vertical blanking intervals and other line intervals in other fields, such as field 1 and line 16. The invention is also useful for use with television signals that comply with standards other than the NTSC standard. For example, Thomson Consumer Electronics, Inc.
A digital television signal, similar to that processed by a DSS® broadcast satellite signal receiver manufactured by (Indianapolis, Inidiana), is a packet of related data rather than by line and field intervals. It is possible to include a data bit stream organized in. Since certain data packets in a digital data stream may represent data components, processing them in accordance with the principles of the present invention provides time information.

In addition to changing the signal format described above, the configuration shown in FIG. 1 can be changed. For example, by combining the data slicer 145 and the controller 110, Motorola Semiconductor (Austin, Texas)
It can be implemented in a single integrated circuit, such as that found in the MC68HC05CC1 microcomputer manufactured by. Like the closed caption OSD processor 140,
Other features, shown as separate features in FIG. 1, can also be implemented with unit 110 and / or unit 145 in a single integrated circuit. These and other changes are within the scope of the invention as clarified in the claims section.

Finally, the correspondence between the description of the claims and the embodiment is shown in parentheses below.

[Claim 1] Seconds component (t
memory (116) for storing data representing a first (tod_hours: tod_minutes) time value, including (od_seconds), and a source for a television signal, including a data component,
The data component is processed into a second (eds_hou
rs: eds_minutes) Controller that determines the time value (110)
And the controller (110) is configured such that the controller (110) has a time difference (t) representing an amount by which the first time value is different from the second time value.
ime_difference) (210) and the controller (1
10) means that the first time value is equal to the second time value by a predetermined time value.
When the time difference indicates that it is different (220) from the time value of, the number of seconds component (tod
_seconds) to a first predetermined number of seconds (230, 250).

[Claim 2] The first time value (tod_hours: tod_minutes) stored in the television receiver.
, Including a seconds component (tod_seconds), which receives a television signal containing a data component and processes the data component to establish a second (eds_hours: eds_minutes) time value. Then, a time difference (time_difference) representing an amount by which the first time value is different from the second time value is determined (210),
When the time difference indicates that the first time value differs from the second time value by a predetermined time value (220), the seconds component (tod_second) is accordingly adjusted.
s) is changed to a first predetermined number of seconds (230, 250). ]

[Brief description of drawings]

FIG. 1 is a block diagram showing a part of a television receiver suitable for applying the present invention.

2 is a flowchart showing a part of a program processing procedure of a controller 110 shown in FIG.

[Explanation of symbols]

 102 Tuner Assembly 104 Tuner Control Unit 110 Controller 130 VIF and SIF Amplifier and Detector 135 Audio Signal Processor 137 Video Switch 140 Closed Caption OSD Processor 145 Data Slicer 155 Video Signal Processor 160 Sync Separator 170 Deflection Unit

 ─────────────────────────────────────────────────── —————————————————————————————————————————————————————————————————————————————————————————————————————————— Panadian_D_D_D.

Claims (2)

[Claims] 1. A memory for storing data representing a first time value including a seconds component, a source of a television signal including a data component, and processing the data component to generate a second time value. A controller for determining, wherein the controller determines a time difference representing an amount by which the first time value differs from the second time value, and the controller determines the first time value by a predetermined time. An apparatus, wherein when the time difference indicates that the value differs from the second time value by a value, the seconds component is changed to a first predetermined seconds value accordingly. 2. A method of maintaining a first time value stored in a television receiving device, including a seconds component, for receiving a television signal including a data component, the data component comprising: To determine a second time value, determine a time difference that represents the amount by which the first time value differs from the second time value, and determine the first time value by a predetermined time value. When the time difference indicates that it is different from the second time value, the method includes changing the seconds component to a first predetermined seconds value accordingly.