FR2889398A1 - Portable digital terrestrial television receiving apparatus, has reception units, to receive low power digital signal, with UHF/VHF antennas to receive signal, where antennas are carried by and connected to apparatus by protecting flap - Google Patents

Portable digital terrestrial television receiving apparatus, has reception units, to receive low power digital signal, with UHF/VHF antennas to receive signal, where antennas are carried by and connected to apparatus by protecting flap Download PDF

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Publication number
FR2889398A1
FR2889398A1 FR0508035A FR0508035A FR2889398A1 FR 2889398 A1 FR2889398 A1 FR 2889398A1 FR 0508035 A FR0508035 A FR 0508035A FR 0508035 A FR0508035 A FR 0508035A FR 2889398 A1 FR2889398 A1 FR 2889398A1
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FR
France
Prior art keywords
terrestrial television
digital terrestrial
antennas
portable digital
television device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
FR0508035A
Other languages
French (fr)
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FR2889398B1 (en
Inventor
Henri Crohas
Yves Gregoire
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Archos SA
Original Assignee
Archos SA
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Filing date
Publication date
Application filed by Archos SA filed Critical Archos SA
Priority to FR0508035A priority Critical patent/FR2889398B1/en
Priority claimed from FR0601427A external-priority patent/FR2889399B1/en
Publication of FR2889398A1 publication Critical patent/FR2889398A1/en
Application granted granted Critical
Publication of FR2889398B1 publication Critical patent/FR2889398B1/en
Application status is Active legal-status Critical
Anticipated expiration legal-status Critical

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Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00Details of, or arrangements associated with, antennas
    • H01Q1/12Supports; Mounting means
    • H01Q1/22Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24Supports; Mounting means by structural association with other equipment or articles with receiving set
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00Antenna arrays or systems
    • H01Q21/28Combinations of substantially independent non-interacting antenna units or systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/41Structure of client; Structure of client peripherals
    • H04N21/414Specialised client platforms, e.g. receiver in car or embedded in a mobile appliance
    • H04N21/41407Specialised client platforms, e.g. receiver in car or embedded in a mobile appliance embedded in a portable device, e.g. video client on a mobile phone, PDA, laptop
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/41Structure of client; Structure of client peripherals
    • H04N21/426Characteristics of or Internal components of the client
    • H04N21/42607Characteristics of or Internal components of the client for processing the incoming bitstream
    • H04N21/4263Characteristics of or Internal components of the client for processing the incoming bitstream involving specific tuning arrangements, e.g. two tuners
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/61Network physical structure; Signal processing
    • H04N21/6106Network physical structure; Signal processing specially adapted to the downstream path of the transmission network
    • H04N21/6112Network physical structure; Signal processing specially adapted to the downstream path of the transmission network involving terrestrial transmission, e.g. DVB-T
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/44Receiver circuitry
    • H04N5/4401Receiver circuitry for the reception of a digital modulated video signal
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/64Constructional details of receivers, e.g. cabinets or dust covers

Abstract

A portable digital terrestrial television device (1) comprises means (30, 31) for receiving a low power digital signal. The reception means (30, 31) comprise, for receiving the digital signal, two antennas (5). , 6) with spatially anisotropic sensitivity, the arrangement of said antennas with respect to the portable digital terrestrial television device being adapted to reduce the coupling between said antennas.

Description

The present invention relates to a digital television device

  portable earth station comprising a device for receiving a low power digital signal.

  Digital terrestrial television (DTT) reception apparatuses are implemented in accordance with the DVB-T standard (Digital Video Broadcasting Terrestial).

  The transmission power of the DTT signal has been set at a low level so that analogue TV transmissions are not disturbed.

  This level of power is sufficient for DVB-T digital terrestrial television reception using rooftop antennas at a height of about 10 meters above the ground.

  An adaptation of the DVB-T standard has been made for the reception of digital terrestrial television on mobile and portable receivers.

  Thus, the DVB-H (Digital Video Broking for Handheld) is a variant of DVB-T digital terrestrial television that takes into account the constraints of portable receivers.

  If the realization of a portable receiver operating a DVB-H signal is easy, the device for receiving a DVB-T signal is much more difficult to develop.

  The reception of the digital television will thus have to be carried out by means of an antenna situated no more than ten meters above the ground but at a height much less important (approximately at 1,5 meters above the ground).

  However, the transmission power of the DTT signal is insufficient for reception by means of such an antenna, in particular for use inside the constructions or in the case of mobile reception.

  Double-stranded antennas used to receive the digital signal of digital television in a vehicle as described by Funke are known and can be found at www.funke.nl. The antennas, in particular the antennas ADSC 410-45T, are adapted to receive in a mobile environment, digital terrestrial television according to the DVB-T standard.

  This antenna is composed of two strands, one strand is of greater height than the second. This antenna is directional and is thus optimized for receiving digital signals from a certain direction. These antennas are attached to the vehicle and are connected to the terminal device by means of a coaxial cable.

  While this antenna is well suited for digital terrestrial television reception according to the DVB-T standard, it is not suitable for DVB-T portable digital terrestrial television sets.

  Thus, the following problems arise when implementing a portable digital terrestrial reception device incorporating reception antennas such as for example: mechanical constraints: in fact, the digital terrestrial television apparatus being portable, the receiving means must be adapted to be also portable and mobile with the digital terrestrial television apparatus; electromagnetic constraints: the digital terrestrial television apparatus in operation emits electromagnetic radiation which must not disturb the reception of the digital signal by the antennas; ergonomic constraints, and constraints related to the characteristics specific to the transmission of DVB-T and DVB-H signals in terms of modulations, frequencies and power of the digital signal.

  The invention aims to remedy the aforementioned problems.

  For this purpose, the present invention provides a portable digital terrestrial television device comprising means for receiving a low power digital signal. The reception means comprise, for receiving the digital signal, two antennas with spatially anisotropic sensitivity, the arrangement of said antennas with respect to the portable digital terrestrial television device being adapted to reduce the coupling between said antennas.

  In view of the above characteristics, the portable digital terrestrial television device according to the invention comprises reception means formed of two antennas. These antennas are arranged so that the antennas are decoupled so as to reduce the influence of one antenna on the other. Thus, the efficiency of the device during its use is optimized by a better sensitivity to a received signal level, which signal is low in DVB-T.

  According to one characteristic, the reception means comprise two tuners associated respectively with said antennas, and the portable digital terrestrial television device comprises diversity processing means adapted to process the digital signals output from said tuners.

  According to these characteristics, the transmission errors are corrected and the noises are filtered. In addition, the multipath echoes of the received signal are processed and the Doppler effect is compensated.

  According to another characteristic, the portable digital terrestrial television device comprises storage means and recording means adapted to store the digital signal in the storage means.

  In this way, the received digital signals can be stored for later viewing.

  According to one characteristic, in said arrangement, the two antennas are arranged at a distance, one of the other, substantially equal to one quarter of the wavelength of the digital signal to be received.

  According to one characteristic, the two antennas are arranged symmetrically with respect to an axis of symmetry of the portable digital terrestrial television device.

  According to one characteristic, the digital terrestrial television device comprises means for connecting the antennas to the portable digital terrestrial television device, and the antennas being mobile between a closed position and an extended position.

  Such a connection makes it possible to deploy the antennas in such a way as to increase the decoupling of the antennas and to minimize the influence of the body of the portable digital terrestrial television device on the reception of the signal.

  According to one characteristic, the device comprises a metal body and when the antennas are in the deployed position, said antennas are remote from the metal body of said portable digital terrestrial television device.

  In this way, the electromagnetic interference with the portable digital terrestrial television device is reduced on the received digital signal.

  Likewise, it is avoided that the digital terrestrial television device obscures the field of reception of the antennas.

  According to one characteristic, said means for connecting the antennas are adapted to be detached from said portable digital terrestrial television device.

  In view of the above feature, the antennas can be detached and positioned to increase the quality of the received signal.

  According to one characteristic, said connection means comprise means for articulating the antennas around a deployment axis of the antennas with respect to the portable digital terrestrial television device.

  According to this characteristic, the position and therefore the orientation of the antennas can be modified so as to improve the quality of the digital signal received.

  According to one characteristic, the device comprises a display screen and a protective valve of said display screen, the valve incorporating the antennas.

  According to one characteristic, the valve is fixed to the portable digital terrestrial television device by hinge hinges, the valve, in the closed position, being above the display screen of said portable digital terrestrial television device, and the flap, in the deployed position, being adapted to serve as a crutch to said portable digital terrestrial television device.

  According to one characteristic, when the valve is in the deployed position, the protective valve forms an angle between 260 and 280 with said display screen of the portable digital terrestrial television device.

  According to one characteristic, said portable digital terrestrial television device is associated with a carrying bag, a flap of the carrying case incorporating the antennas, and the flap being movable between a closed position and an extended position relative to the digital television device. portable earth.

  According to one feature, when the flap is in the deployed position, the flap is adapted to serve as a stand for said digital television device

portable earth.

  According to another characteristic, the portable digital terrestrial television device comprises a body comprising a front face provided with a display screen, two longitudinal edges and two lateral edges. Both antennas are adjacent to the side edges of the portable digital terrestrial television device.

  This arrangement makes it possible to place the antennas away from the magnetic radiation zone of the terminal. In addition, this arrangement prevents the body of the digital terrestrial television device from occulting the field of reception of the antennas.

  According to one embodiment, the digital terrestrial television device comprises means for connecting the antennas to the portable digital terrestrial television device, the means for connecting the antennas being positioned respectively at one end of the lateral edges of the portable digital terrestrial television device and aligned along a longitudinal edge of the portable digital terrestrial television device.

  According to one characteristic of this embodiment, said means for connecting the antennas comprise means for articulating the antennas around a deployment axis of the antennas with respect to the portable digital terrestrial television device, the antennas being mobile between a closed position and an extended position, and in that when the front face of said portable digital terrestrial television device is disposed in a plane inclined with respect to a horizontal plane and said antennas are in the deployed position, the value of the angle between said antenna deployed and said horizontal plane is between 40 and 50.

  According to one characteristic, the antennas comprise two strands of unequal heights, the high-level strand being adjacent to one of said lateral edges of the portable digital terrestrial television device and the small-height strand being disposed at a distance from said lateral edge of the digital television device portable earth.

  Such an arrangement makes it possible to reduce the coupling between the antennas formed of two strands of unequal heights.

  According to one characteristic, each antenna comprises two strands of unequal heights.

  Other aspects and advantages of the invention will appear on reading the following detailed description of particular embodiments, given by way of non-limiting examples. The description refers to the accompanying drawings, in which: - Figure la illustrates in top view a portable digital terrestrial television apparatus according to a first embodiment of the invention; FIG. 1b schematically illustrates the portable digital terrestrial television apparatus; Figure 1c illustrates in side view the portable digital terrestrial television apparatus according to the first embodiment of the invention; Figure 2 illustrates the position on the portable digital terrestrial television apparatus of two-wire antennas of different sizes; FIG. 3a illustrates, in plan view, the orientation of the antennas according to the first embodiment of the invention; FIG. 3b illustrates, in side view, the orientation of the antennas according to the first embodiment of the invention; FIG. 3c illustrates an alternative positioning of the antennas in front view; FIG. 4 illustrates a second variant of positioning the antennas in front view; - Figure 5a shows a top view of a portable digital terrestrial television apparatus comprising a valve integrating the antennas according to a second embodiment of the invention; FIG. 5b illustrates in side view a portable digital terrestrial television apparatus comprising a closed valve integrating the antennas according to the second embodiment of the invention; - Figure 5c illustrates in side view a portable digital terrestrial television apparatus comprising the open valve integrating the antennas according to the second embodiment of the invention; and FIG. 6 is a side view of a portable digital terrestrial television apparatus incorporated in a bag according to a third embodiment of the invention.

  Referring to Figure 1a, a particular embodiment of a portable digital terrestrial television apparatus 1 is illustrated.

  The apparatus 1 comprises, on a front face 1a, a display screen 2 for multimedia data, in particular digital terrestrial television, control means 3, for example buttons, and audio outputs 4. The body of the apparatus Portable digital terrestrial television system 1 is substantially rectangular and has two longitudinal edges 1b and two side edges 1c.

  The invention consists in providing means for receiving television data, in particular digital terrestrial television, via suitable antennas, so that the apparatus can be used both in an immobile environment, particular, inside a house, only in a mobile environment, for example inside a car.

  To do this, the portable digital terrestrial television apparatus comprises two antennas 5, 6, having a non-isotropic or anisotropic sensitivity in space, that is to say that the reception sensitivity of an antenna is dependent on its orientation in space.

  Indeed, an antenna is said to be spatially anisotropic if it is optimized for reception in a preferred direction. We also speak of directive antenna.

  These antennas are small in size and operate in particular in diversity although they are located near the terminal and at a short distance from one another.

  A mechanism implementing diversity is described in the document A revolution for indoor DVB-T mobile reception and outdoor DVB-T mobile reception present at the Internet address http: //www.dibcom. net / us / document / DiBcom Diversity White Paper web.pdf.

  Indeed, the propagation of electromagnetic waves between a transmitter and a receiver follows multiple paths because of the presence of various obstacles (construction, vegetation, etc.) on which the signal is reflected and refracted.

  In addition, if the receiver moves, an effect known as the Doppler effect occurs.

  A diversity implementing mechanism performs the appropriate processing such that, from the two received signals on both antennas, this mechanism produces a signal of better quality in terms of signal level and signal-to-noise ratio.

  This implementation makes it possible to correct the transmission errors and to filter the noises, to process the echoes due to the multiple paths taken by the received signal and to compensate for the Doppler effect in the case of a reception in a moving vehicle.

  As illustrated in FIG. 1b, the portable digital terrestrial television apparatus comprises two reception means 30 and 31, each composed of an antenna 5, 6, of an amplifier LNA (Low Noise Amplifier). 32 and 33 and a tuner (also known as tuner) 34 and 35.

  An implementation of the mechanism implementing the diversity 36 is based on the signals generated by the reception means 30 and 31.

  This mechanism 36 performs diversity processing by analyzing digitally and instantaneously the two output signals of the two tuners 34 and 35.

  To do this, comparison and combination operations of the two signals are performed to overcome the ambient noise, noise induced by the propagation of the signal from its point of emission, long and short echoes due to reflections on the obstacles. encountered, as well as the Doppler effect inherent to a mobile reception.

  These processes make it possible to generate a signal having a signal / noise ratio C / N better than either of the two signals taken independently.

  In this way, we obtain an improvement in the quality of the reception and the effective coverage area.

  The digital signal at the output of the diversity implementing mechanism 36 may, for example, be viewed on the display screen 2 of the portable digital terrestrial television apparatus, or stored in storage means 38 by recording means .

  As illustrated in FIG. 1a, the antennas are, for example, arranged symmetrically with respect to an axis of symmetry X of the portable digital terrestrial television apparatus. However, other arrangements of the antennas with respect to the apparatus can be envisaged.

  According to a first embodiment, the antennas 5, 6 are respectively close to two opposite sides of the portable digital terrestrial television apparatus, and in particular arranged adjacent to the side edges 1c of the portable digital terrestrial television apparatus.

  This arrangement makes it possible to move the antenna as far as possible away from the electromagnetic radiation elements of the apparatus.

  This arrangement on the portable digital terrestrial television apparatus makes it possible to distance one antenna as much as possible from the other, so as to reach, if possible, a distance substantially equal to the quarter-wave of the signal to be received, ie 12.5 cm at a frequency of 600 MHz. In this way, if an antenna receives a signal of minimum amplitude, that is to say in a hollow of the signal, then the second antenna receives a signal of maximum amplitude, that is to say in a belly of the signal.

  It should be noted that the bands IV and V used for broadcasting terrestrial television in France vary from 470 to 860 MHz (channels 21 to 69).

  Similarly, the arrangement of the antennas with respect to the portable digital terrestrial television apparatus and in particular vis-à-vis the metal body of the apparatus is such that these antennas are as far away as possible from the metal body.

  In this embodiment, the antennas 5, 6 are attached to the portable digital terrestrial television apparatus by connecting means 7 described later.

  FIG. 1c illustrates the portable digital terrestrial television apparatus, viewed from the side and disposed in an inclined position allowing a user to comfortably view multimedia data, while having the apparatus placed on a horizontal support plane, such as a desk. The holding in inclined position for the user is ensured by means of a crutch 8.

  In this embodiment, the antennas 5, 6 are highly directional and are each formed of two strands of unequal heights, as shown in Figure 2. Other geometric antenna shapes may also be considered.

  The antennas 21 and 31, shown schematically in FIG. 2, respectively correspond to the antennas 5 and 6 of FIG.

  According to one embodiment, the long-length strands 21a and 31a are positioned near the apparatus while the short-length strands 21b and 31b are remote from the apparatus. Such an orientation of the antennas makes it possible for the areas of maximum sensitivity to have minimum or even no overlap, thus minimizing the coupling.

  Indeed, an antenna although considered a receiver, it partially re-emits signals and can disturb another antenna nearby. This is called coupling between the antennas.

  Thus, the implementation of the decoupling according to the invention thus makes it possible, on the one hand, to minimize or even avoid the coupling and, on the other hand, not to receive the same signal coming from the same direction.

  To do this, we adopt an antenna arrangement so that the areas of maximum sensitivity of the antennas are disjoint.

  As illustrated in FIG. 3a, the antennas 5 and 6 are fixed on the portable digital terrestrial television apparatus 1, at one end of the lateral edges 1c of the apparatus, that is to say at the two corners of the apparatus, by connecting means 7.

  In this embodiment, the antennas 5 and 6 are connected to two opposite corners of the apparatus in alignment with a longitudinal edge of the apparatus.

  They can be deployed, for example, by rotation around the fixation of the portable digital terrestrial television apparatus.

  Such an articulated connection of the antennas to the portable digital terrestrial television apparatus makes it possible to deploy these antennas around a deployment axis corresponding here to a longitudinal edge 1b of the apparatus.

  In addition, the deployment of the antennas relative to the plane of the device further reduces the disturbances created by the device, and / or improve the reception of the signal according to its polarity.

  Figure 3b illustrates the portable digital terrestrial television apparatus at a position allowing a user to view the screen of the device and having the antennas deployed.

  As illustrated in FIG. 3b, the angle α with the horizontal plane of the antennas 5 and 6 can vary from 0 to 360. However, it is observed that an angle value of 40 to 50 between the deployed antenna and the horizontal plane is optimal for simultaneous reception of both horizontal and vertical polarizations of the signal.

  According to another variant of the deployment of the antennas on the portable digital terrestrial television apparatus, the antennas 5, 6 are deployed in the plane of the apparatus as illustrated in FIG. 3c.

  According to an alternative positioning of the antennas on the portable digital terrestrial television apparatus, the antennas 5, 6 are positioned on one of the longitudinal edges 1 b as illustrated in FIG. 4.

  These antennas 5, 6 can pivot in the plane of the portable digital terrestrial television apparatus or perpendicularly to this plane.

  This deployment of the antennas makes it possible to place them outside the magnetic radiation zone of the portable digital terrestrial television apparatus, that is to say in a manner remote from the ground plane of the portable digital terrestrial television apparatus, and to prevent the device from occulting the field of reception of the antennas.

  The presence of these antennas near the portable digital terrestrial television apparatus also requires adaptations of the portable digital terrestrial television apparatus, especially for the signal processing in the integrated circuits of the apparatus by the reception means for exploit diversity to filter noises, process echoes, correct errors and compensate for the Doppler effect.

  The implementation carried out makes it possible to obtain a better sensitivity for a given level of received signal, with an effective treatment of the Doppler effect allowing, in particular, use in a moving vehicle.

  This implementation also allows a greater capacity to deal with the different noises induced by the electromagnetic interference due to the radiation emitted by the terminal which is added to the disturbances of the signal undergone during its propagation, in particular the echoes produced by the paths multiples of the signal.

  Indeed, the reception frequencies in DVB-T are close to the harmonics of the radiation frequencies of the active components of the terminal which can create electromagnetic interference.

  As seen previously, according to a first variant embodiment for connecting the antennas to the portable digital terrestrial television apparatus, the antennas 5 and 6 are fixed to the apparatus by means of an articulated connection 7. In this embodiment of realization, the antennas are directly fixed on the edges of the terminal at the upper corners.

  This articulated attachment allows the deployment of antennas by rotation around the attachment point as shown in Figure 3.

  The angles of the two antennas in the deployed position relative to the horizontal support plane of the portable digital terrestrial television apparatus may be different. The variation of the deployment angles of the antennas makes it possible to search for the position giving the best quality of reception.

  The attachment of the antennas to the portable digital terrestrial television apparatus can also be removable so that the antennas are detached, so that these antennas can be placed at a distance from each other and away from the digital television apparatus portable earth. In this way, the effectiveness of diversity will be greater.

  In the case of use in a location with a roof receiving antenna, the built-in antennas can be removed and the device is then connected to the rake antenna cable, thus offering, in principle, better signal to noise ratio and therefore a better quality of reception.

  According to an alternative embodiment for the connection of the antennas to the portable digital terrestrial television apparatus, illustrated in FIGS. 5a, 5b and 5c, the antennas 5 and 6 are incorporated in a removable valve 9 for protecting the screen.

  The removable flap is attached to the portable digital terrestrial television apparatus by hinge hinges, for example on a longitudinal edge 1b of the portable digital terrestrial television apparatus.

  FIG. 5a illustrates the portable digital terrestrial television apparatus 1 provided with a valve 9 protecting the display screen in the closed position. For this, the flap is placed above the display screen. The valve 9 comprises the antennas 5 and 6 positioned adjacent to the lateral edges of the device.

  The antennas 5, 6 are also arranged symmetrically with respect to an axis of symmetry X of the digital terrestrial television apparatus

portable 1.

  Figure 5b illustrates this device 1 in side view where the valve 9 obstructs the screen so as to protect the latter.

  According to this variant, the deployment of the antennas is done by opening the valve as shown schematically in Figure 5c. The flapper, once opened, forms an angle of 260 to 280 with respect to the front of the portable digital terrestrial television apparatus. This valve can also serve as a crutch, allowing such a use that the portable digital terrestrial television apparatus is placed on a horizontal plane so as to make the display of the screen adapted to the user. Similarly, in this open position of the valve, the antennas 5 and 6 form, then an optimum angle for receiving the signal, between 40 and 50, relative to the horizontal plane.

  Finally, the removable valve 9 can be removed in the following cases.

  In a first case, the apparatus is used in a fixed situation where it may be advantageous to detach the valve and place it away from the terminal to improve the quality of reception.

  According to a second case, it may be advantageous to detach the valve and remove the antennas thereof to place them away from each other and away from the portable digital terrestrial television apparatus.

  Finally, when the user is in a location with a rooftop receiving antenna that provides a better signal-to-noise ratio, the flip is removed and the portable digital terrestrial television set is connected to the cable. antenna rakes using an adapter cable which connects the coaxial jack to an antenna input of the portable digital terrestrial television apparatus.

  According to another variant embodiment for connecting the antennas to the portable digital terrestrial television apparatus, the antennas 5 and 6 are incorporated in the flap of a carrying case 10 of the portable digital terrestrial television apparatus 1, such as shown in Figure 6.

  The bag is attached to the portable digital terrestrial television apparatus by means of a clip 11.

  According to this variant, the deployment of the antennas is done by opening the flap of the bag as shown in Figure 6.

  In addition, this flap can be provided so that, once returned and attached to the back of the terminal, it serves as a crutch allowing such a use that the portable digital terrestrial television apparatus 1 is placed on a plane, with the front panel equipped of the screen in an inclined position.

  The portable digital terrestrial television device may be removed from the case in the following cases.

  In a first case, the device is used in a fixed situation and it may be advantageous to detach the bag and the antennas incorporated therein and to place them away from the terminal to improve the quality of reception.

  According to a second case, it may be advantageous to detach the bag and take out the antennas to place them away from each other and away from the portable digital terrestrial television device.

  Finally, when the user is in a location equipped with a reception antenna installed on the roof and offering a better signal-to-noise ratio, it is possible to remove the case with the antennas incorporated and to connect the television apparatus. portable digital terrestrial at the descent of the rake antenna using an adapter cable which connects the coaxial socket to the antenna input of the portable digital terrestrial television apparatus.

Claims (19)

  1.   A portable digital terrestrial television device comprising means for receiving a low power digital signal, characterized in that the reception means (30, 31) comprise, for receiving the digital signal, two antennas with spatially anisotropic sensitivity, the arrangement of said antennas with respect to the portable digital terrestrial television device being adapted to reduce the coupling between said antennas.
  2.   Portable digital terrestrial television device according to claim 1, characterized in that receiving means (30, 31) comprise two tuners associated respectively with said antennas, and the portable digital terrestrial television device comprises means for processing the diversity. digital signals adapted to process the digital signals at the output of said tuners.
  3.   3. Portable digital terrestrial television device according to one of claims 1 or 2, characterized in that the portable digital terrestrial television device comprises storage means and recording means adapted to store the digital signal in the means of storage.
  4.   4. Portable digital terrestrial television device according to any one of the preceding claims, characterized in that in said arrangement, the two antennas are arranged at a distance, one of the other, substantially equal to a quarter of the length of the wave of the digital signal to be received.
  5.   5. A portable digital terrestrial television device according to any one of the preceding claims, characterized in that the two antennas are arranged symmetrically with respect to an axis of symmetry of the portable digital terrestrial television device.
  6.   6. Portable digital terrestrial television device according to any one of the preceding claims, characterized in that it comprises means for connecting the antennas to the portable digital terrestrial television device, and the antennas being mobile between a closed position and a deployed position.
  7.   7. A portable digital terrestrial television device according to claim 6, characterized in that the device comprises a metal body and when the antennas are in the deployed position, said antennas are remote from the metal body of said digital television device
    portable earth.
  8.   8. Portable digital terrestrial television device according to one of claims 6 to 7, characterized in that said means for connecting the antennas are adapted to be detached from said portable digital terrestrial television device.
  9.   9. Portable digital terrestrial television device according to one of claims 6 to 8, characterized in that said connecting means comprise means for articulating the antennas around a deployment axis of the antennas with respect to the digital television device portable earth,
  10. 10. Portable digital terrestrial television device according to one of claims 6 to 8, wherein the device comprises a display screen and a protective valve of said display screen, the valve 30 incorporating the antennas.
  11.   11. Portable digital terrestrial television device according to claim 10, characterized in that the valve is fixed to the portable digital terrestrial television device by hinge hinges, the valve, in the closed position, being above the screen of viewing said portable digital terrestrial television device, and the valve, in the deployed position, being adapted to serve as a crutch for said portable digital terrestrial television device.
  12.   Portable digital terrestrial television device according to claim 11, characterized in that, when the flap is in the extended position, the protection flap forms an angle of between 260 and 280 with said display screen of the portable digital terrestrial television device. .
  13.   13. Portable digital terrestrial television device according to one of claims 6 to 8, characterized in that said portable digital terrestrial television device is associated with a carrying case, a flap of the carrying case incorporating the antennas, and the flap being movable between a closed position and an extended position relative to the portable digital terrestrial television device.
  14.   14. Portable digital terrestrial television device according to claim 13, characterized in that, when the flap is in the deployed position, the flap is adapted to serve as a stand for said portable digital terrestrial television device.
  15.   15. Portable digital terrestrial television device according to one of claims 1 to 9, comprising a body having a front face provided with a display screen, two longitudinal edges and two side edges, characterized in that the two antennas are adjacent at the side edges of the portable digital terrestrial television device.
  16.   16. Portable digital terrestrial television device according to claim 15, characterized in that it comprises means for connecting the antennas to the portable digital terrestrial television device, the means for connecting the antennas being positioned respectively at one end of the lateral edges of the antenna. portable digital terrestrial television device and aligned along a longitudinal edge of the portable digital terrestrial television device.
  17.   17. A portable digital terrestrial television device according to claim 16, characterized in that said means for connecting the antennas comprise means for articulating the antennas around a deployment axis of the antennas with respect to the portable digital terrestrial television device, the antennas being movable between a closed position and an extended position, and in that when the front face of said portable digital terrestrial television device is disposed in a plane inclined with respect to a horizontal plane and said antennas are in an extended position, the the value of the angle between said deployed antenna and said horizontal plane is between 40 and 50.
  18.   18. Portable digital terrestrial television device according to one of claims 13 to 17, characterized in that the antennas comprise two strands of unequal heights, the high-end strand being adjacent to one of said lateral edges of the portable digital terrestrial television device. and the small height strand being disposed at a distance from said side edge of the portable digital terrestrial television device.
  19.   19. Portable digital terrestrial television device according to any one of the preceding claims, characterized in that each antenna comprises two strands of unequal heights.
FR0508035A 2005-07-27 2005-07-27 Portable ground terminal digital television device comprising a device for receiving a low power digital signal Active FR2889398B1 (en)

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FR0508035A FR2889398B1 (en) 2005-07-27 2005-07-27 Portable ground terminal digital television device comprising a device for receiving a low power digital signal

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR0508035A FR2889398B1 (en) 2005-07-27 2005-07-27 Portable ground terminal digital television device comprising a device for receiving a low power digital signal
FR0601427A FR2889399B1 (en) 2005-07-27 2006-02-17 Portable ground terminal digital television device comprising a device for receiving a low power digital signal
EP06291211.8A EP1748651B1 (en) 2005-07-27 2006-07-26 Portable terrestrial digital television device comprising a low power digital signal reception device
US11/493,924 US20070026790A1 (en) 2005-07-27 2006-07-27 Portable digital terrestrial television device comprising a device for receiving a low power digital signal

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FR2889398A1 true FR2889398A1 (en) 2007-02-02
FR2889398B1 FR2889398B1 (en) 2008-03-21

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FR (1) FR2889398B1 (en)

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