KR19980060784U - VSI system with channel search function by band - Google Patents

Abstract

The present invention relates to a VSI system having a channel search function for each band. In the related art, when auto-searching a channel registered in a memory by a user, a V.E. low (VL) band → V. It was difficult to avoid the problem of longer channel scanning time in such a system because VH) band → UHF band was automatically scanned.

According to the present invention, under the control of the microcomputer 13 and the microcomputer 13 for scanning the tuner for each band if there is an automatic search for each band by the user through the key input unit 15 so as to improve such a conventional problem. By VSI system having a band-by-band channel search function comprising a tuner unit for performing a channel-specific channel selection operation, and a key input unit 15 for providing a band-specific selection input command to the microcomputer 13. The user can shorten the channel selection time during channel auto search.

Description

VSI system with channel search function by band

The present invention relates to a VSI system having a channel search function for each band in VSI having a channel tuning means using a frequency synthesis method. In particular, in this system, a user tunes a channel for each channel by a channel stored in the system. By doing so, the user can significantly reduce the signal selection time by channel auto search.

The VSI system is an electronic device that is commonly used with a TV receiver, and a general circuit block diagram of the VSI system is illustrated in FIG. 1.

Here, a tuner unit 23 for receiving a regular broadcast signal from an antenna of a VSI system to perform channel tuning, a microcomputer 22 for controlling a VSI system, and an OSD circuit 31 for generating an OSD screen. And a channel memory 32 of the VSI system, a key matrix 21 for various key operations together with the remote control transmitter, a deck 26 for recording / playback deck operation, an RF converter 28, and video signal processing. The video processing unit 29, the TV receiver unit 30 and the like is composed of.

In addition, the tuner unit 23 includes a PLL (phase locked loop) 25 generating frequency tuning data, and a tuning circuit 24 including a tuning circuit, a local oscillator, a mixer, and the like as shown in FIG. )

In addition, the circuit associated with the tuning means of the frequency synthesizing method associated with the above operation is shown in more detail as shown in Figs.

Here, the microcomputer 22 of the system control unit, the channel selecting unit 23, the PIF unit 33, the video processor 34, and the like are included.

Such a frequency synthesizer (FS) tuning means (FS) tunes the phase of the frequency to be compared with the phase of the reference frequency (crystal oscillator (determining the reference frequency using X-tal)). Local oscillation frequency) It is a method of making a local oscillation frequency of the desired channel by tuning to match.

In this case, as shown in FIGS. 2 and 3, when the video signal detected by the PIF unit 33 is input to pin 4 of the video processor TA 8605N; It is input to pin 3 of the synchronous detection IC (LM 567C) of the PIF unit 33. Then, it compares with the reference frequency (f _o = 15734 Hz) of RC connected to pins 5 and 6, and outputs a logic 0 signal to the microcomputer 22 when it matches. The timer microcomputer 22 judges the presence / absence of the synchronization signal based on the level of this signal (logic 1 or 0) and executes the tuning operation.

In addition, in order to perform broadcasting tuning, the microcomputer 22 and the PEL Icy 25 on the channel selecting section 23 perform the following operations.

That is, 18 bits of data from the microcomputer 22 are transmitted to the PIEL 25, and the 18 bits of data input to the PIEL 25 are the first 4 bits of the band selection switch data, The upper 9 bits of the next 14 bits are data input to the main counter divider, and the lower 5 bits are input to the Swallow Counter Divider to determine the local oscillation frequency.

The 18-bit data value for each channel is stored in the microcomputer 22, and this data is valid only when the ENABLE terminal is logic 1.

On the other hand, the PEL I 25 is a channel up 1, Direct (Direct) tuning, from the microcomputer 22, the data, enable, clock signal corresponding to the channel is input to the P iel I 25 The data signal is serial data of 18 bits, and a binary code corresponding to each channel is stored in the timer microcomputer 22, and the band of the PIEL Icy 25 is input by the input band switch data. One of the three selected pins becomes logic 0, and 12V is input to each of the tuning circuit input terminals V _L / V _H / U of the tuner circuit 24.

Fourteen bits (Band SW DATA), followed by the top 9 bits of the system's main counter and the lower four bits, are entered as a swell counter to determine the division of the programmable counter. Done.

For example, f r : frequency 512 divided by 4 MHz as the reference frequency, f s : frequency divided by 8 x 32 x (M + 3/32) input local oscillation frequency as the comparison frequency, f r : oscillation frequency of the VCO. (prescater input frequency, the local oscillator frequency) and, VCO output f o (local oscillation frequency), the frequency division by f _s and the reference frequency through a prescaler, programmable counters, the (Vottage Contralled oscillator) f r ( 78125KHz) and the phase of In comparison, the difference is converted into a DC voltage through a DA converter and applied to the tuning voltage of the local oscillator.

Then, the local oscillation frequency f o , which is changed according to the change of the VT voltage, is inputted back to the prescaler and compared with f r through the same path. In other words, the phases are compared and the VT voltage is changed by looping continuously until f r = f s .

In addition, when the desired channel is selected, the microcomputer 22 outputs 18-bit data corresponding to the channel to the PEL Icy 25, and the PEL I 25 is the local oscillation frequency f of the corresponding channel. o )

After 50 ms after the data is output, the microcomputer 22 determines whether or not there is a SYNC and changes the path of tuning operation as follows.

That is, when logic 0 is inputted to the SYNC terminal of the microcomputer 22 after data output, the window search operation is performed, and when logic 1 is input, the SYNC search operation is performed.

In the above-described synchronous search operation, the first data value is increased by 5, and if 5 steps are increased, if the synchronization signal is not detected, the original data is reduced by 5 steps and then outputted, and the data value is increased by 5 steps by 5 steps. To increase.

Each time the data value changes by 1, the local oscillation frequency changes by f r x 8 (62.5KHz), so the local oscillation frequency changes by 62.5KHz x 5 = 312.5KHz at 1 step change.

If the SYNC signal is detected at any step of the SYNC search, the SYNC search operation is stopped and the window search operation is performed. On the other hand, if all the steps are swept (± 6 step sweep) and the SYNC signal is not detected, the microcomputer 22 sends the first output data to the PEL Icy 25 as it is (the local oscillation frequency is f). Fixed to o ) Complete the tuning operation.

In the case of window search, the SYNC signal is detected, and then the data value is increased (decreased) by 1 to find the AFT window.

The change in local oscillation frequency for one step is 62.5KHz and the window search range is f o ± 1.875MHz (± 30 step). The data is incremented by 1 (by 52.5 KHz) until AFT − is detected at the SYNC signal detection frequency. Increase it by 30 steps (+ 1.875 MHz), then decrease the data by 1 to fo-1.875 MHz.

If the point where the AFT − is detected by increasing the frequency is called 'a' and the point where the AFT + is detected by the decrease of the frequency as 'b', the timer microcomputer 41 adjusts the optimum adjustment (at the time of 6 point detection − 1 stem), the data is output to the PEL Ish 43 to complete the AFT operation and complete the tuning operation.

As described above, the channel tuning operation by the frequency synthesis method is conventionally performed through the above operation. In this process, a plurality of predetermined channels are stored together with the channel memory connected to the microcomputer 22, and then the channel tuning operation is performed. Was.

On the other hand, in the system as described above, a user performs a channel preset operation using the screen interactive OSD, and the process is performed as follows.

TABLE 1

v

If you press 3 above,

TABLE 2

When 2 is pressed, channel data currently being received is preset and registered in the memory. The registered channel is assigned to the VHFh / VHFl / UHF (V _L / V _H / U) band when the user selects a specific channel. Irrespective of the channel search, the channel search was performed continuously from 02 to 69, which is the entire channel area.

However, in the conventional system as described above, a channel registered in a channel memory scans a channel selected by a user regardless of a plurality of bands (V _L / V _H / U). In the case of selecting the first channel, the system scans from two VHF areas to the UHF area to find 69 channels, which makes it difficult to avoid the problem of lengthy channel search in the system.

An object of the present invention is to enable the user to tune channels by band so as to improve the above problems, thereby significantly reducing the channel tuning time in such a system.

In particular, the present invention performs a channel selection operation for each band under the control of the microcomputer and a microcomputer for channel scanning the tuner for each band if there is an automatic search for each band through the key input unit of the system so as to realize the object of the above example. It is characterized by a VSI system having a channel-specific channel search function including a tuner unit and a key input unit for providing a band-specific selection input command to the microcomputer.

Hereinafter, more specific features of the present invention will be understood by describing the same in detail with the accompanying drawings.

1 is a circuit block diagram of a Video Cassette Recorder (VCR) system with a typical OSD function.

2 is a reference diagram showing an extract of a frequency synthesis channel selector related to FIG.

3 is a reference diagram for understanding a synchronization signal detection operation in FIG.

4 is a system circuit block diagram of the present invention.

5 is an embodiment showing a channel search program for each band of the present invention

** Explanation of symbols on the main parts of the drawing **

11. Tuner part 12. IF part

13. Microcomputer 14. Channel memory section

15. Key in

100: Channel search program by band

That is, Figure 4 shows an excerpt of the circuit block of the VSI system having a channel-specific channel search function of the present invention.

Here, the microcomputer 13 scans the tuner for each band if the user selects the band automatic search through the key input unit 15 of the system, and the tuner for performing the channel selection operation for each band under the control of the microcomputer 13. A unit 11 and a key input unit 15 for providing band-specific selection input commands to the microcomputer 13 are constituted.

In the system, an IF unit 12 for intermediate frequency processing of the RF video signal selected from the tuner unit 11 and a rear end of the IF unit 12 are amplified and processed. A video processor 16, an audio processor 17 for amplifying and processing an audio signal, an OS 18, a channel memory 14, and the like are provided.

According to the present invention of such a configuration, the user calls a function menu screen through the key input unit 11 and then enters the band-specific auto search mode to select a channel for each band desired by the user.

For example, when the user selects a VLH band (VL) band through the key input unit 15 and the user presses a desired channel, the microcomputer 13 recognizes that the channel band is the VHF area. Afterwards, the number of channel scannings is significantly reduced by scanning the 02-06 channels of the VHS row area among the V-etch areas of the 02-13 channel.

In addition, if a user selects a VH band and then presses a specific number of channels, the microcomputer 13 also scans the 07 to 13 channel channels of the VH high region to reduce the time for channel search. You will be able to.

In addition, when the user selects UHF band, scanning is performed from 14 to 83 channels, which also reduces the scanning time by scanning only the UHF area without scanning the VHF area. You can do it.

Meanwhile, the above operation is performed by the microcomputer 13 together with the band-specific channel search program 100 as shown in FIG. 5, which is a function as shown in Table 1 above when the system checks whether a user inputs a function key. A menu screen is output, and it is checked whether the user has selected the channel preset mode on the screen, and if it is the preset mode, the channel preset screen shown in Table 2 is output (step 101).

Thereafter, it is checked whether the user selects the auto set mode on the channel preset screen, and outputs the channel screen for each band in the auto set mode (step 102).

The user checks whether the user selects the VL autoset mode from the band-specific screens, and executes VL autoset in the VL autoset mode (steps 103 and 104).

In addition, it is checked whether the user selects the VH autoset mode from the band-specific screens, and if the VH autoset mode is selected, the VH autoset is executed (steps 105 and 106).

In addition, it is checked whether the user selects the UHF autoset mode from the band-specific screens, and executes the UHF autoset in the UHF autoset mode (steps 107 and 108).

In addition, it is checked whether the user selects all band autoset modes from the band-specific screens, and if all band autoset modes are performed, autoset is performed for all bands (steps 109 and 110).

The present invention enables to perform channel selection and search operations in a bandial system by band, so that the time required for channel auto search for broadcast reception in such a system can be remarkably shortened, so that the use efficiency of such a system can be increased. will be.

Claims (1)

In the VRS system having the channel tuning function by the frequency synthesizing method including the microcomputer 22 and the OS unit 31, if there is automatic band selection by the user through the key input unit 15 of the system, A microcomputer 13 for scanning a tuner for each band, a tuner unit 11 for performing a channel selection operation for each band under the control of the microcomputer 13, and a band-specific selection input command to the microcomputer 13; VSI system having a channel search function for each band, characterized in that the configuration comprising a key input unit 15, etc. to provide