FR2840493A1 - DIGITAL UPGRADE MODULE FOR ANALOG TELEVISION SET - Google Patents

Abstract

Digital upgrade module for analogue television set This module replaces a conventional analogue tuner, to allow an analogue television set to receive digital channels. It includes: an input (2) receiving analog or digital television (RF) signals, an analog tuner (3), a digital tuner (4) associated with a digital / analog converter (6) and an intermediate frequency modulator (7), a selector (5) of the signal (IF) coming from the analog tuner (3) or from the modulator (7), an output (8) delivering the intermediate frequency (IF), and control means (9) receiving , interpreting and transmitting tuner commands (AGC, SDA, SCL).

Description

correspond to the moire correction data.

  The present invention relates to an upgrade module-

  digital for analog television posse.

  While the market for digital terrestrial and cable television receivers is expanding rapidly, the majority of television equipment currently sold remains analog. Very generally, this situation will not change significantly in the coming years. One obvious possibility of "digital upgrading" for owners of analog television sets is the use of an external converter box. Such external bolts are widely available commercially, and are connected to the television stand by means of a television aerial cable or, preferably, by

  through a specific connector ("PERITEL" socket).

  A major drawback of all of these outdoor enclosures is the need to add an auxiliary enclosure on the existing television stand, said enclosure being piloted from a second remote control which is added to the main remote control of the television stand. This solution therefore remains

  bulky, expensive and complicated to use.

  Another, much more practical solution would be to simply "upgrade" the television set itself. However, since different manufacturers of television sets use totally different solutions to control the electronic components of their television sets, such an upgrade would in any case be too con

  specific to each manufacturer, therefore relatively expensive.

  The object of the present invention is therefore to provide a solution which is highly independent of the manufacturers of television sets, which represents a new concept for the upgrading of television sets, allowing analog television sets to function as receivers.

digital television.

  The invention is based on the general idea set out below: - Electronic circuits and connectors, which are found in an analog television set of recent design, relatively wind

  complex. However, the following description may apply to most,

  or even the totality of the current analog television possessions.

  Such a television set is a device which mainly comprises, in combination: - a cathode ray tube, or other equivalent device, making it possible to display the image on a screen; - an electronic control and piloting unit for the electrical and logical operation of the device, that is to say a central unit which controls the cathode ray tube and which ensures interactivity with the user; - a tuned amplifier or tuner which receives television signals and converts them into a standardized form; - a box which contains all the components, in particular those

indicated above.

  The control and piloting units, the screens and the boxes differ significantly, from one manufacturer to another. On the other hand, there is a manufacturing standard for tuners, which receive at their input the television signals coming from an antenna, and which deliver at their output an intermediate frequency intended for a subsequent procedure of signal processing. Modern tuners (called "PLL", short for "Phased Locked Loop") are controlled by a set of commands, which can be transmitted by a data bus, from the electronic control unit and

steering.

  Based on these observations, the invention provides a digital leveling module for analog television poses, which replaces a conventional analog tuner, being "compatible" with the connection used for conventional tuners, this module upgrade that can be used as a retrofit of a preexisting analog television set (that is to say as part of an after-sales service), or be directly incorporated during the manufacture of new television sets. To this end, the digital leveling module, object of the invention, essentially comprises, in combination: - an input intended to receive television signals, analog or digital, in particular from a television antenna, an analog tuner, in connection with the input, - a digital tuner, also in connection with the input, - at the output of the digital tuner, a digital-to-analog converter, - an intermediate frequency modulator, connected to the output of the converter, - a selector signal, namely the intermediate frequency, from the analog tuner or precise modulator, - an output delivering the intermediate frequency, and - control means receiving, interpreting and transmitting

tuner controls.

  Thus, the digital leveling module, object of the present invention, has an input for antenna signals, exactly like a conventional analog tuner, and it works with the usual tuner controls. However, inside this module, there are all the components necessary for the reception of analog television signals and digital television signals, and for the conversion of these two types of signals into an intermediate frequency, such as that usually delivered by analog tuners. The upgrade module also contains all the "intelligence" necessary to interpret the

  controls qutil re, coit, and to control the functions of a conventional tuner.

  Thus, this module is fully compatible with existing analog TV tuners and posses, which eliminates any need to modify or

  to adapt the central command and control unit of the television set.

  The invention will be better understood from the following description

  of an example of realization of this digital upgrade module for

  analog television installation, with reference to the accompanying schematic drawing.

  The only figure in the drawing is a block diagram of the upgrade module.

  In the drawing, the reference 1 indicates a television antenna socket, receiving a high frequency RF television signal, which is brought to an input switch 2. The latter has a first output connected to the input an analog tuner 3, and a second output connected to

  The input of a digital tuner 4.

  The output of the analog tuner 3 is connected directly to an input of an output switch 5. The output of the digital tuner 4 is connected to the input of a digital analog converter 6, the output of which is connected to the input of an intermediate frequency modulator 7. The output of the

  modulator 7 is connected to another input of output switch 5.

  This switch 5 has an output connected to a standard connector 8 for analog tuner, the connector 8 thus delivering the intermediate frequency IF to the other components of the television set concerned. The standard connector 8 also has various input connections to the module, receiving and transmitting: - a supply voltage + Vcc - the GND earth - an AGC signal (automatic gain control)

  - SDA and SCL clock data signals.

  AGC, SDA and SCL signals are fed to a micro-controller

  9, which sends control signals SC over a control bus 10.

  As indicated by the diverging arrows, these signals SC are in particular directed towards the input switch 2, towards the analog tuner 3, towards the digital tuner 4, towards the intermediate frequency modulator 7 and

to the output switch 5.

  The micro ic co ntrol 9 pos having sufficient memory capacity, the operation of the module is established as follows: The micro-controller 9 has the possibility of scanning the analog and digital frequency bands, and of sorting the channels detected, according to a predefined algorithm (for example according to the known system "ATS", abbreviation of "Automatic Tuning System"), in particular by automatically tuning the television position on the frequencies of the detected emissions. All the frequencies, and the other parameters, are stored in the memory of the microcontroller 9. This process is carried out in "background"; it does not need to be terminated by an aerial flight action, nor to be commanded by the command and control unit of the television set. Each detected channel, regardless of its source, is associated with a "tuning frequency" which could be selected by a standard tuner. The most important channels (depending on the procedure used, such as "ATS" see above) are preferably stored at wind frequency levels

  usually used for cable channels. -

  Tuning for reception of a channel is achieved by selecting one of these "tuning frequencies". Depending on the physical source of the selected channel, the leveling module will use, thanks to the input switch 2, either the analog tuner 3, or the digital tuner 4, to receive the selected channel. If it is an analog channel, the analog tuner 3 directly delivers the intermediate frequency IF, which is then transmitted, by the output switch 5 and the connector 8, to the main control and piloting unit of the television station, for broadcasting programs of the selected analog channel. If a digital channel is selected, the digital tuner 4 delivers a digital video signal DV, which is transformed in the converter 6 into an analog video signal AV (itself converted) in the modulator 7 into the intermediate frequency IF. As in the previous case of an analog channel, the intermediate frequency IF is finally transmitted, by the output switch 5 and the connector 8, to the main control and piloting unit of the television set, here for the broadcasting of selected digital channel programs. As follows from the above, the leveling module according to the invention may give the impression of agreeing to a certain frequency, whereas it in fact performs a completely different action. This is intended for

  simulate a standard TV set tuner.

  In the practical implementation of the invention, it may be difficult to place all the components of this leveling module in a single box which would be the size of a standard tuner. To circumvent this difficulty, it is possible to realize the module with a physical separation between, on the one hand, the components generating the intermediate frequency IF, which must be located at the location of the usual tuner !, and, on the other apart, the rest of the module, the components of which, connected by cables, can be placed anywhere in the enclosure of the

  television, in which there is usually some free space.

  It goes without saying that the invention is not limited to the only embodiment of this digital leveling module for analog television installation which has been described above, by way of example; on the contrary, it embraces all variants respecting the same principle, whatever

  constructive details, or details of signals and their processing.

Claims (4)

  1. Digital leveling module for analog television set, replacing a conventional analog tuner, characterized in that it comprises, in combination: - an input (2) intended to receive television signals (RF), analog or digital, in particular coming from a television antenna (1), - an analog tuner (3), in connection with ['input (2), - a digital tuner (4), also in connection with [' input (2), - at the output of the digital tuner (4), a digital / analog converter (6), - an intermediate frequency modulator (7), connected to the output of the converter (6), - a selector (5) signal (IF), namely the intermediate frequency, from the analog tuner (3) or the modulator (7), - an output (8) delivering the intermediate frequency (IF), and - control means (9) receiving , interpreting and transmitting   tuner controls (AGC, SDA, SCL).   2. digital leveling module for analog television set, according to claim 1, characterized in that it is used in   retrofitting of a preexisting analog television set.   3. digital leveling module for analog television posse, according to claim 1, characterized in that it is directly   incorporated during the manufacturing of a new television set.   4. Digital leveling module for television set   analog according to any one of claims 1 to 3, characterized in that   that it is carried out with a physical separation between, on the one hand, the components generating the intermediate frequency (IF), located at the location of the usual tuner !, and, on the other hand, the rest of the module including the components, connected by cables, placed in a place in the enclosure of the