JPH0151114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television receiver capable of receiving teletext, and in particular, after a selection operation is made to receive a desired still image display program, until the program is actually received, that is, This proposed a television receiver that can display on a CRT, etc., the waiting time until the content of the program is displayed on the CRT.

In teletext broadcasting, a signal related to still image display is superimposed on a specific scanning line area during the vertical blanking period of a normal television program (hereinafter referred to as the main program) and transmitted, and the television receiver side transmits the signal once per field of the main program. This transmitted signal is stored in a memory device, the stored contents are read out repeatedly, and the operation of reproducing and displaying one still screen (one page of a still image display program) is repeated. In order to enhance the usefulness of teletext broadcasting, a plurality of types of still image display programs are prepared, such as weather forecasts, traffic information, and sports news, and these are periodically and repeatedly transmitted. That is, the first part of program A
page is transmitted, followed by the first page of program B, the first page of program C, and if there are 10 programs, the first page of the 10th program J is transmitted, and then the second page of program A is transmitted.
page, the second page of program B, the second page of program C, and so on. A transmission signal related to a still image display program includes a code that specifies the program, a code that specifies the background, a code that specifies the pattern of characters or figures to be displayed (hereinafter referred to as characters),
A code that specifies which line the code that specifies this character should be displayed on,
Regarding the codes (hereinafter referred to as character signals) that specify the characters that are diverse, but occupy the largest quantity, such as display characters and color codes for their backgrounds, one transmission (i.e., one field of the main program) (one transmission per time), information for one scanning line of the character display portion on the static screen is sent. Assuming that one still image screen consists of 15 characters/line and 8 lines of text, the amount of information in the signal transmitted at one time is a little less than one character, and the period of one frame is 1/60 seconds. The total number of characters on one screen is 120, and signals other than character signals are also required.
It will take approximately 2.5 seconds to send the screen (1 page).
Therefore, it takes about 25 seconds for all 10 types of programs to be transmitted one page at a time. Therefore, if you select to receive a certain program, the maximum time is approximately 22.5
As a receiver, you will not be able to receive the program for a few seconds, and you will feel like you have to wait a long time.Also, you may be wondering if there is a problem with the transmitting or receiving system. I have doubts about this. The length of this waiting time is naturally proportional to the number of types of still image display programs, so if the number of programs is reduced, the waiting time can be shortened and the above-mentioned frustration can be alleviated, but on the other hand, There is a situation in which teletext broadcasting loses its significance unless there is a certain number of different types of programs, and it has been desired to resolve this contradictory problem.

The present invention was made against this background, and the present invention has been developed until the selected still image display program is actually received, that is, the content of the next page of the program is displayed.
It is an object of the present invention to provide a teletext television receiver for teletext broadcasting, which has a configuration in which the display is displayed on a CRT, etc. while the waiting time until the display is displayed on the CRT is changed every moment, and the receiver's feeling of irritation as described above can be alleviated. do.

The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a block diagram schematically showing only the portions related to the present invention of a television receiver according to the present invention. In the figure, a decoder 1 inputs a signal related to a still image display program discriminated from the received signal (obtained once per field of the main program), and receives a code (hereinafter program code) that specifies the still image display program in each signal. ) is detected, and an address signal ADS with contents corresponding to each program is sent to the memory device 2.
It also issues a reset signal RST and a preset signal PST to each of the plurality of counters 3A, 3B, .

The number of counter group 3 is the same as the type of still image display program (or more in consideration of future increase in the number of programs),
For example, it consists of ten counters 3A, 3B, 3C, . The clock generator 4 is configured to count the number of one-second period clock pulses TCP inputted from the clock generator 4. Therefore, in this television receiver, the counter group 3 should be operated in the up-count mode for some time after the power is turned on.
A down switching signal UDS is provided to the counter group 3.

Now, if we look only at still image display programs, 10 types of programs A, B, C...J are periodically transmitted one page at a time in order, as shown in Figure 3A. Based on the program code of the incoming signal, a reset signal RST is issued to the counter assigned to each program during the period when the signal related to that program is being received, and when the reception of the signal related to that program is finished. Disappears the reset signal RST. Therefore, after the reset signal RST disappears, each counter starts counting the time pulse TCP from 0 in the up-count mode.
For example, if we look at program A and the counter 3A assigned to it, as shown in Figure 2 (b), when the first signal related to program A is transmitted, the counter 3
The reset signal RST for A begins to be issued,
At the point when the last signal related to program A disappears, the reset signal disappears, and counting of time pulses TCP is then started. However, the next time program A is transmitted, the reset signal RST appears again, and the count content of counter A returns to 0, but the count value just before that is assigned to counter A in memory device 2. Store it in area 2A. This area 2A
The designation is made by the address signal ADS that the decoder 1, which receives the signal related to the program A immediately thereafter, issues to the memory device 2 in accordance with the program code. The counter 3A is reset as described above by the reset signal RST, and is also reset by the timing pulse.
Since TCP is counted, the count value (count up value) of counter 3A stored in area 2A is the time (number of seconds) from when the signal related to program A is no longer transmitted until the next time it is transmitted, in other words. Then, the data represents the time obtained by subtracting the period _TA during which the signal related to program A is transmitted from the repetition period _TA of program A. Similarly, regarding the programs B, C...J and the counters 3B, 3C...3J assigned to these respectively, and furthermore, the areas 2B, 2C...2J in the memory device 2 assigned to the counters 3B, 3C...3J, for example, the counter 3B. As shown in Fig. 2C, the reset signal RST is received from the decoder 1 while the signal related to program B is being received, and after the signal disappears, the time measurement pulse TCP is counted, and then the count-up value immediately before being reset is calculated. is stored in area 2B of the memory device. Therefore, in the areas 2A, 2B, 2C...2J of the memory device 2, the time elapsed from when the signals related to each program A, B, C...J are no longer transmitted until the next signal is transmitted (hereinafter referred to as program extinction period). ) will be stored in units of seconds. Such counting by the counter group 3 and storage in the memory device 2 are repeated while the up/down switching signal UDS is such that the up-counting mode should be operated. Then, at least once for each program, after a time sufficient to time the program extinction period and store it, the up/down switching signal UDS is output to the counter group 3.
can be switched to the content that should be operated in down count mode.

Therefore, counter group 3 is an up/down switching signal.
After the UDS is set to operate in the down count mode, each time a signal related to each program is transmitted, at an appropriate timing in between, the stored contents of the area in the memory device 2 related to that program, i.e. The program extinction period is preset in the corresponding counter, and the preset contents are subtracted by the timekeeping clock pulse TCP from the time when the signal related to that program ends, in other words, from the time when the program moves from that program to the next program, that is, a down count is performed. I'm trying to keep up. Note that the counter is not counted down while the program corresponding to the counter is being transmitted. This is the program A stored in the counter 3A and the area 2A of the memory device 2.
To explain the program disappearance period S _A (=T _A −t _A ), as shown in FIG. 3A, each program A,
B, C...J are repeatedly and periodically transmitted in this order. Then, as shown in FIG.
The preset signal is activated at the point when the program changes from program A to program A.
PST is given, thereby presetting the storage contents of area 2A, ie, the program extinction period S _A of program A, in counter 3A. The designation of this area 2A is performed by the address signal ADS that the decoder 1, which is receiving the program A at this time, issues to the memory device 2 in response to this program. After the transmission of the signal related to program A ends (the time when program A shifts to program B), a down count is performed to subtract the number of input clock pulses TCP from S _A. Then, the next time a signal related to program A is transmitted, S _A is preset again, and the same operation is repeated thereafter. The period during which the above-mentioned down count is performed is equal to the program reduction period S _A of program A, and from this value, the counter 3A is incremented by 1 every second.
Since the content of the program A is decreased, in short, the signal for the next program A is transmitted when the down count value reaches 0. In this way, the counter 3A always holds the time until the next signal related to program A is transmitted, that is, the waiting time of program A, while the signal related to program A is not being transmitted. . Similarly, the counters 3B, 3C...3J always indicate the time until the next signal related to programs B, C...J is transmitted while the signals related to the corresponding programs B, C...J are not being transmitted, i.e. Holds the waiting time of programs B, C...J.

Reference numeral 5 denotes a data selector which performs a down count according to a program selection code input from a keyboard 6 provided on the operation panel of the receiver to select a still image display program. The count contents of a predetermined counter in the counter group 3 are selected and outputted to the code converter 7. That is, for example, when a numerical value assigned to program A is keyed in by operating the keyboard 6, a corresponding program selection code is input to the data selector 5, and the data selector 5 selects the count content of the counter 3A that is counting down. and outputs this to the code converter 7. The code converter 7 converts the input data into e.g.
It is converted into an ASCII code, and this ASCII code is output to the character generator 8. Therefore, the output of the character generator 8 corresponds to the count contents of the counter 3A etc. corresponding to the program A etc. selected at that time, that is, a character pattern of numbers representing the waiting time in seconds. On the other hand, a ROM (read-only memory) 9 stores a predetermined character pattern, for example, a message pattern such as "Please wait for a second". The contents of this ROM 9 and character generator 8 are determined by the address generation circuit 10.
The character pattern signals corresponding to the beams of the CRT are read out sequentially by read addresses (horizontal addresses, vertical addresses) issued in synchronization with the image display of the CRT, and the character pattern signals corresponding to the beams of the CRT read out from both are sent to the character generator 8 in the synthesis circuit 1. Character pattern is ROM9
is synthesized so that it appears before the character pattern of
The signal is output to the CRT display circuit. Therefore, from the counter 3A etc., the data selector 5
For example, if the first numerical value output to the code converter 7 is "12", as shown in Figure 4.
A message "Please wait 12 seconds" will be displayed on the CRT. After that, the contents of counter 3A etc. will be decremented every second, so the "12" part of the above display will be updated to be decremented by 1, and the message "Please wait 1 second" will be displayed. 1 second after it appears, keyboard 6
A signal related to the program selected by the operation will be transmitted and its display will start, and the message will disappear. Note that the display position, display form (characters, background color), etc. of the message can be arbitrarily determined. Alternatively, only the number of seconds of the waiting time may be displayed on a numeric indicator such as an LED provided separately from the CRT.

The input/output control of the various signals and data mentioned above is performed by a CPU (central processing unit), not shown.
A part of the circuit shown in FIG. 1 may be replaced by the processing function of this CPU.

In the case of the television receiver according to the present invention configured as described above, the counters 3A, 3B, 3C, . 3J
holds the waiting time of each program, which changes every moment.
Therefore, if you select a desired program at any point after the above-mentioned time has elapsed, unless that point is within the period in which that program is being transmitted, the waiting time of that program, that is, the next signal related to that program, will be changed. Until the image is actually received after being transmitted, that is, CRT
The time until the program is displayed is immediately displayed, and this time is displayed while changing every moment. Furthermore, if the time when a certain program is selected is within the period during which the signal related to that program is being transmitted, the data selector 5 does not read the contents of the corresponding counter, and therefore the current The counter contents (program extinction period S _A for each program, etc.) are not displayed, and the display of that program is immediately started. However, in this case, since the signals after the program selection time affect the display of the screen (page) being transmitted, the entire screen is not necessarily displayed.

In addition, in the above explanation, it will take some time after the power is turned on.
The counter group 3 is operated in up-count mode to measure the program extinction period for each program and store this in the memory device. It is also possible to operate the program in an up-count mode to rewrite the program erasure period in each area of the memory device 2. With such a configuration, even if the number of programs or the repetition period of each program is changed during reception, this can be handled. In addition, in the above-described embodiment, the program disappearance period S _A , etc. is measured, this is preset in the measuring means (counter 3A, etc.), and this is subtracted by the time clock from the time when the transmission of the signal related to the program ends. However, the target of measurement and subtraction is not limited to the program extinction period, but may be any program repetition cycle or time data related to the repetition cycle such as the program extinction period, and the preset timing and subtraction start timing can also be used. The timing is not limited to the above embodiment. The means for measuring the repetition period and the like and the means for subtracting it (timekeeping means) may be configured with separate counters. Furthermore, in a broadcasting system in which each program has the same period, the means for measuring the program extinction period and the area of the memory device for storing the measurement results may be each single.

As described in detail above, according to the present invention, when a desired still image display program is selected, the waiting time until the program is actually received is displayed in an ever-changing manner. It is possible to realize an excellent television receiver for teletext broadcasting that does not make people feel uneasy.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a block diagram schematically showing the main parts of a television receiver according to the present invention, and FIG. FIG. 3A and FIG. 3B are explanatory diagrams while the counter group operates in the down-counting mode, and FIG. 4 is a drawing showing an example of the waiting time display format. 1...Decoder, 2...Memory device, 3...Counter group, 5...Data selector, 8...Character generator.

Claims (1)

[Claims] 1. In a teletext television receiver that receives teletext broadcasting in which multiple types of still image display programs are periodically and repeatedly transmitted, means for measuring the repetition period of each program or time data related thereto, and a method for measuring this. means for storing results, and presetting said measurement results for each program as each program is transmitted, and subtracting the content after a specific time associated with the period during which each program is transmitted; The apparatus is characterized in that, when an arbitrary program is selected to be received, the waiting time until the selected program is actually received is displayed based on the contents of the timer. Teletext television receiver for teletext broadcasting.