WO2000035180A1

WO2000035180A1 - Electromagnetic-wave audio-video street door phone or interphone

Info

Publication number: WO2000035180A1
Application number: PCT/IT1998/000380
Authority: WO
Inventors: Biagio Ombrini
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-12-04
Filing date: 1998-12-29
Publication date: 2000-06-15
Anticipated expiration: 2001-06-04
Also published as: IT1303644B1; AU1784299A; ITMI982630A1

Abstract

Audio-video street door phone and interphone (10) for residential or work premises in general, in which there are one or more rooms, grouped or single, such as apartments (12, 13), apartment blocks (11), business and industrial offices, hotels, detached houses and other kinds, consisting of an external apparatus (50) placed at the street door (25) of the apartment block or at the doors of residential or work premises, comprising a push-button panel, a microphone, a receiver, possibly a telecamera, an electric lock on the street door (25) or on other doors, and of devices (85, 130) inside the residential or work premises comprising a set of button switches, a receiver, a microphone, possibly a monitor, controls for the electric lock (70) and other parts, in which transmission and reception of sounds, and views if any, between the external apparatus (50) and the internal devices (85, 130) is made by electromagnetic waves.

Description

Electromagnetic-wave audio-video street door phone or interphone

The invention concerns devices called street door phones or interphones. Presently known audio and/or video interphones, connecting two or more rooms, or residential apartments, in offices, hotels, nursing homes, or connecting buildings one to another either through a caretaker or directly by the bell panel outside the building, are widely used. An apparatus for this purpose generally consists of a network of wires, of a DC feeder and of devices for conversation and possibly for viewing, and of means for remote opening of doors and street doors.

The device for conversation and possibly for viewing substantially consists of a microphone-receiver unit with or without monitor, of a bell for receiving calls and of one or more button switches with which to call other listening posts. The apparatus may consist of a single pair of inter or street phones, it may be centralised so that, from one main apparatus, a conversation can be carried on with any of the others; it may be intercommunicating in the sense that, from any one apparatus, a conversation can be carried on with any of those connected to it, each may comprise a number of buttons equivalent to the number of devices; communication may be possible between a caretaker and residents, or conversations between the resident in one apartment and someone using the street door apparatus equipped with a powerful loudspeaker. Each apartment device can be provided with a button to open the door or street door, this being most useful in cases where there is no caretaker or in the case of a detached house with garden.

A simplified form of this apparatus is one comprising a push-button panel next to the main street door with an amplifier and possibly with a screen for video.

The apparatus placed at the door is connected by electric cables to house interphones placed in the various apartments.

As already stated, each interphone has a speaker-receiver set and a more or less complex push-button panel.

The simplest form is that found in an apartment block where there is a push-button panel with loudspeaker, and possibly with a video screen, close to the street door.

By means of the push-button panel the caretaker can be called to open the street door by working a switch connected to an electric lock.

When a visior presses the button for an apartment, a buzzer or bell sounds inside that apartment.

When the person called lifts the receiver the bell stops ringing and the person can talk to, or even see, the visitor. If a camera is placed next to the push-button panel, a view of the visitor cap be received at the street phone in the apartment called.

After talking to or even after seeing the visitor, the person called can open the electric lock on the street door by the button on the apparatus in the apartment and admit the visitor. It will be clear from the foregoing that an apparatus of this kind can in general comprise a call device next the street door, call devices in each apartment, an electric lock on the street door and also on the door of each apartment, direct connections between the devices in the apartments and one in the caretaker's lodge. All these call devices are usually run off the apartment block's main electricity system through a feeder, generally DC.

It will also be clear from the foregoing that either in the case of an apartment block or in that of a detached house, and according to the facilities required, the apparatus and its connections are somewhat complex.

Even if such requirements are of a simple kind, troubles often arise due to the complex electrical connections as they concern those for control, conversation, possibly viewing between the various interphones both inside and outside the building, and most of all there is the difficulty caused by the user having to run towards the interphone, perhaps from some distance in the apartment, to answer the call, talk to the caretaker and then work the means for opening doors or the street door. In many cases these necessities are complicated by the size of the apartment which may make it difficult to answer the bell in time, such difficulties being made almost insuperable in the case of sickness or infirmity, temporary or otherwise, of the person called. The invention here described overcomes these difficulties as will now be explained.

Subject of the invention is an audio-video street and interphone for houses or work places in general, consisting of one or more rooms, grouped or single, such as apartment blocks, commercial and industrial premises, hotels, detached houses and other types. This kind of apparatus consists of a device placed at the street door of the building concerned and comprises a push-button panel, a microphone, a receiver, possibly a telecamera, an electric lock on the street door or on other doors and of devices placed inside the building comprising a push-button panel, receiver, microphone, possibly a monitor, controls for working the electric lock, and other parts.

According to the invention transmission and reception of sounds, and possibly of pictures, controls between external and internal devices, takes place through the use of electromagnetic waves. In one type of execution transmission and reception of sounds, of ima- ges, and controls between external and internal devices, is made entirely by electromagnetic waves, so that the external apparatus, possibly the electric lock on the street door or internal doors and the internal devices are fitted for transmisson and reception by electromagnetic waves. The electromagnetic waves are radio waves.

The internal devices are portable.

Electric feed is supplied to the internal devices from the electricity mains or from an independent source, as the case may be. The internal devices supplied from an independent source of electricity can be wall-mounted or placed on a table for easy availability.

Independent electric feed is supplied by batteries or by rechargeable accumulators inside the devices.

Accumulators are recharged at a recharging point connected to the mains, electrical connection between accumulators and recharging points being automatic by insertion of the devices in specially made positions at said recharging points.

The recharging point can be wall-mounted or on a table.

The internal devices indicate a call by a bell, by a winker light or by vibrations.

The internal devices placed in groups or single housing units or in the rooms of such units or at a work place, can advantageously be connected one to another or to the external apparatus.

In such cases the internal devices are equipped to vary the intensity and type of audio or visual call indications so as to distinguish between calls made from different rooms inside a house and those from a work place.

For greater security the internal devices can be approved and fitted with means for preventing cloning or wire tapping.

The internal devices can be miniaturized to make them pocket size like a mobile phone.

The range of action of these devices inside a house or work place can be such as to permit their use in nearby areas outside for communication with a visitor who is using the external apparatus.

In another type of execution the internal devices comprise a wall- mounted base and a mobile handset.

This fixed base is connected to the external apparatus by the known means of transmitting electric signals through wires.

The mobile handset, fed by an independent source of electricity, is connected to the fixed base by devices for transmitting and receiving electromagnetic waves, permitting connection with the external apparatus even by removing the handset from its base and taking it outside the house or work place as far as is possible with the range of action for this type of transmitting and receiving device.

Independent electric feed for handsets can be provided either by accumulators that automatically recharge when the handset is put back on its base, or by batteries. Advantageously the handsets can be fitted to connect with another handset in the house or work place through the devices on the external apparatus either by means of these devices or directly. The electromagnetic waves can be infrared rays. The invention offers evident advantages. Connection between external and internal devices or with the base of the internal handset, by electromagnetic waves, offers innumerable advantages as the internal device can be used at practically any point in the house or even outside it, if within the range of action established between the transmitting and receiving devices. One or more of these independent or rechargeable devices can be placed in any room of the house or work place for quick availability.

Several devices can be installed in a single house or work place and can emit different call signals to distinguish them.

This is especially useful in the case of invalids or for anyone who may be unable to move, even momentarily, to answer a call. A phone and even video network can thus be established between the external apparatus of a house or group of houses or work places and the user, for calls made both inside such buildings or nearby, to said user's great advantage and comfort. The possibility of using several internal devices, recharging them in turn, or even simultaneously if several recharging positions are set up, means availability of a number of means of communication with the external apparatus as may be most useful for the house or work place concerned. The further possibility of transforming street and interphone devices already installed by simply replacing them as described with the fixed base or a handset connected to said base by electromagnetic waves, makes it possible to put this invention into execution within a very short time in practically any house or work place and at a negligible cost to the great advantage of users.

Characteristics and purposes of the invention will be made still clearer by the following examples of its execution illustrated by diagrammatically drawn figures.

FigJ Street door bell device for an apartment block with porter's lodge and electric lock, connected by electromagnetic waves to the external and internal devices with electric feed from the mains or from an independent source, perspective.

Fig. 2 Apparatus for the device in Fig 1 , fed from the electricity mains and with a bell, placed in a wall-mounted support, perspective. Fig. 3 The wall-mounted support in Figure 2, perspective.

Fig. 4 Exploded view of the external apparatus in Figure 1 , perspective.

Fig. 5 Detail of the internal device with independent feed, placed in a table stand, perspective.

Fig. 6 Variant of the device in Figure 5, with a winker light, perspective. Fig. 7 Variant of the device in Figure 5, with a vibrator, perspective.

Fig. 8 Audio-video street door bell installation for an apartment block as in Figure 1 with internal independently fed devices, perspective.

Fig. 9 Detail of the external apparatus in Figure 8, perspective.

Fig. 10 Internal device of the installation in Figure 8, wall-mounted, pers- pective.

Fig. 11 Internal device of the installation in Figure 8 with bell and winker light, perspective.

Fig. 12 Diagram of approximate electronic layout of the electromagnetic wave circuit for transmission and reception, in the fixed position of the audio-video device in Figure 8 and 9.

Fig. 13 Diagram of the approximate electronic layout for audio-video street door bells.

Fig. 14 Detail of the transmitter in the electronic layout in Figures 12, 13. Fig. 15 Detail of the receiver in the electronic layout in Figures 12, 13. Fig. 16 Audio door bell installation for an apartment block with porter's lodge and electric lock, with the usual wiring between the external bell and the internal devices, wall-mounted bases for mobile handsets connected to said bases by electromagnetic waves, perspective.

Fig. 17 Mobile apparatus for the installation in Figure 16 with mains-fed handset in its wall-mounted support, perspective. FigJ 8 The apparatus in Figure 17 with handset off its base, perspective. FigJ 9 Handset similar to that in Figure 18, battery-fed, perspective. Fig.20 Audio-vedeo mobile door bell during removal of the audio-video handset from its wall-mounting, perspective.

The street door bell installation 10 for the building 1 1 with apartments 12 and 13, porter's lodge 20 and street door 25 comprises the external apparatus 50, electric lock 70 on the street door, charging positions 80 on a table and 81 wall-mounted, for internal devices 85 in the apartments 12 fed off the electricity mains, and for internal devices 120 and 130 with electric feed from an independent source, placed in the apartments 13 on a wall support 90 and on a table support 91 respectively. Electricity is supplied from the mains 18 through the meter 21 , feeder 22, distribution boxes 30-32 and electric wiring 40-46.

As seen in Figure 1 , said boxes and wires connect the table device 26 in the porter's lodge 20, with receiver-microphone and switch to open the electric lock 70, with the various internal devices 85 in the single apartments, with the external apparatus 50, with the electric lock 70, and with the switch 71 to open the electric lock.

The fixed external apparatus 50 comprises the wall box 51 , the electronic unit 52, the grid 53, the modular button panel 54 with buttons 55. The electronic unit 52 in turn comprises the electronic card 60 with circuits 61 for opening the electric lock 70, the receiver 62, microphone, 63 and antenna 65.

The charging position 81 comprises the support 87 to be wall-mounted, with cavity 88 in which the device 85 comfortably fits.

On the base 89 of said support is a plate 96 with four contacts 97 connected by a cable 98 to the transformer 93 that can be plugged into the electricity mains with the plug 94.

The devices 85 comprise the body 100 with inside it the electric accumulator 101 whose contacts 102 automatically connect by matching up with contacts 97 on the support 87.

Inside the body 100 is the receiver 110, transmitter 1 11 and the antenna 112, while in the centre is an electronic card 114 connected to the described parts, as well as to the bell 1 13, and to switches 1 15 and 116. When the bell 113 rings, transfer to audio connection is made by switch 115.

The push button 1 16 served by the pilot light 117 opens the electric lock 70 on the street door 25.

When a visitor presses a button 55 on the push button panel 54, the bell 1 13 rings due to connection between antennas 65 and 112 on the fixed apparatus 50 and on an internal device 85 respectively.

At this point the person called can remove the phone 85 from its support 87 or 91 , respectively in positions 81 and 80, and by pressing the switch 1 15 create connection with the microphone-receiver unit 62, 63 on the fixed external apparatus 50, and by pressing the switch 116 can open the electric lock 70 on the street door 25 to allow the visitor to enter.

Figures 5-7 illustrate three versions of the apparatus described, all independently fed.

The device 120 with body 121 is placed on the table base 95 and presents substantially the same basic features as those described, with independent electric feed by batteries 122, and presents the electronic card 124 connected to the receiver 110, transmitter 11 1 , switch 115 for transferring bell contacts 1 13 to those of the receiver-transmitter group, the antenna 1 12 and switch 1 16 with pilot light for opening the electric lock 70 on the street door 25. The device 130 in Figure 6 has a winker light 131 associated to, or instead of, the bell 1 13.

The device 135 in in Figure 7 has a vibrator 136 instead of the bell 1 13 or winker light 131 . Figure 8 shows a building 141 with apartments 142 and 143, street door 25 with electric lock 70, fitted with a video apparatus 140 substantially the same as the apparatus 10 already described, but improved by addition of the video. The external apparatus 150, electric lock 70 and switch 71 to open it by hand are connected by means of the distribution box 35 and electric cables 47 to the feeder 22 supplied through the electricity meter 21 from the mains 18. Allowing for the fact that each user can check the identity of a visitor through the video installation, a porter's lodge has been omitted.

The fixed external apparatus 150 comprises a wall box 151 , electronic unit 152, grid 153, modular button panel 154 with buttons 155. The unit 152 in turn comprises the electronic circuit 160, receiver 161 , microphone 162, antenna 165 and telecamera 167. The video-bell devices 170, with or without wall-mounting 180, may be seen in the apartments 142, 143.

A user 190, immobilised in a wheel-chair, is holding a video device. Another video device 170 is placed in its wall-mounted support 180. Said video device 170 with body 177 presents batteries 173 for indepen- dent feed, an electronic card 174 connected to the receiver 175, the transmitter 176, liquid crystal monitor 182, winker light 183, switch 178 for transferring contacts from the bell 184 to those of the receiver- microphone unit, the switch 179 with pilot light 181 for opening the electric lock 70 on the street door 25, and the antenna 186. The video image can be adjusted by the controls 187, 188 connected to the electronic card 174.

When a visitor presses a button 155 on the button panel 154, the bell 184 rings and the winker light 183 comes on following contact between the antennas 165 and 186, respectively on the fixed external apparatus 150 and on a device 170.

At this point the person called presses the switch 178, so connecting the audio-video group in the device 170 with the audio-video group in the fixed external apparatus 150. If the person called recognises the visitor by these means, he can press the switch 179 to open the electric lock 70 on the street door 25 and allow the visitor to enter.

Figures 12-15 present approximate electronic layouts for the audio-video devices 150, 170.

Figures 14 and 15 refer in particular to the audio-video transmitter- receivers 162-176, 161 -175.

The following installations comprise internal devices formed of a fixed base and a mobile handset. Wired connections in the known type of street door external apparatus to the internal devices are made through said fixed base. Connections between said base and the handset are made by electromagnetic waves. The street door bell installation 200 for the building 201 with apartments 202, porter's lodge 210 and street door 215 comprise an ordinary external apparatus 220 with telecamera 221 , electric lock 225 on the street door and the internal devices 250 with fixed wall mountings 251 for mobile handsets 252-255 connected to said fixed mountings by electromagnetic waves. Electric feed comes from the main line 18 through the meter 21 , feeder 22 and cable 23.

The usual electric connections are made through the distribution boxes 230 and cables 231 to the external apparatus 220, electric lock 225, table installation 225 in the porter's lodge, and fixed bases 251 for the internal devices 250.

The internal device 250 comprises a fixed wall-mounting 251 and handset 252.

The fixed base 251 comprises the plate 260, seven contacts 261 connected to the wires in the cable 252 emerging from the hole 235 in the wall of the apartment 202, the electronic circuit 265 for transformation of electric signals into electromagnetic waves and vice versa, connected to the contacts 261 and to the antenna 266. The handset 252 comprises contacts 270 for electric feed from the accumulator 271 , the receiver 272, transmitter 273, bell 274, switch 275 for passing from ringing tone to sound, the switch 276 for opening the street door.

It will be clear that all electric pulses transmitted from the external apparatus are passed to the individual mobile handsets 251 -254 on the internal devices 250 through the cables 231 between the external apparatus emitting the electromagnetic waves among said fixed bases 251 and said mobile handsets. Figure 19 illustrates a handset 255 similar to the handset 252 already described, this being battery fed.

Figure 20 illustrates a handset 285 similar to those described, fitted with a monitor 290 on the fixed base 286.

The following may be seen: the antenna 297, receiver 292, electronic card 294, bell 274, switch 295 for transforming the ringing tone to sound, the switch 296 for opening the electric lock on the street door, accumulators 291 , transmitter 293 and contacts 298 at the base of the handset for connection to electric feed.

Visible in the fixed base 286 are: the electronic circuit 299 connected to the antenna 287 and electric cable 231 with wires for connection to the contacts 288 for transmission of electric signals between the external apparatus and said fixed bases for the handsets.

When a visitor presses a button on the button panel on the external apparatus 220, the bell 274 rings or other call signal is made due to wire connections with the base of the internal devices between the antennas 266 and 277 and the base 251 and a handset 252 respectively.

At this point the person called can take the handset from its base and by pressing the switch 275, establish voice connection with the external apparatus 220, then by pressing switch 276 can open the electric lock 225 on the street door 215 to allow the visitor to enter. The video on the handset obviously permits a view of the visitor.

A family of users can of course have several handsets available like 251 , 254 and others, each for one member of the family occupying different rooms or even outside the apartment building, but within the range of action of the transmitting and receiving devices placed between the handsets and their bases in each housing or working unit. A number of handsets, or internal devices generally, can obviously be recharged one at a time on the recharging sets provided, or else a number of recharging sets can be made on a single base.

In particular, the user can use a handset to call the porter's lodge from outside, or any of the people in the apartments if suitable means are added to the various devices

Claims

1. Audio-video street door phone or interphone (10, 40, 200) for residential or work premises in general, consisting of one or more rooms, grouped or single, such as apartments (12, 13, 142, 143, 202), apartment blocks (1 1 , 141 , 201), business and industrial offices, hotels, detached houses and others, consisting of an external apparatus (10, 150, 220) placed close to the street door (25, 215) of the apartment block or doors to the residential or work premises, comprising a push-button panel (54, 154), microphone (63, 132), receiver (62, 161), possibly a telecamera (167, 221), electric lock (70, 225) on the street door (25, 215) or on other doors, and of devices (85, 120, 130, 135, 170, 250-255, 285, 286) placed inside the units (12, 13, 142, 143, 202). comprising calling means (113, 131 , 136, 184, 274), a set of push-buttons (1 15, 178, 187, 188, 275, 276, 295, 296), a receiver (1 10, 175, 272, 292), microphone (1 1 1 , 176, 273, 293), possibly a monitor (182, 290), controls (1 16, 179, 276, 296) for the electric lock (70, 225) and other parts, characterized in that transmission and reception of sounds and of views, if any, between the external apparatus (50, 150, 220) and the internal devices (85, 120, 130, 135, 170, 250-255, 285, 286) is made by the use of electromagnetic waves.

2. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that transmission and reception of sound, possibly of views and of controls between the external apparatus (50, 150) and internal devices (85, 120, 130, 135, 170) is made by the use of electro- magnetic waves.

3. Audio-video street door phone and interphone (10, 140, 200) as in claim 1 , characterized in that the electromagnetic waves are radio waves.

4. Audio-video street door phone and interphone (10) as in claim 1 , characterized in that the internal devices (85) are electrically fed from the electric mains (18).

5. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (85, 120, 130, 135, 170) are portable.

6. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (120, 130, 135, 170) are electrically fed by an independent source of electricity (122, 173).

7. Audio-video street door phone and interphone (10, 140) as in claim 6, characterized in that the internal devices (120, 130, 135, 170) fed by an independent source of electricity can be fitted onto a wall-mounted support (90, 180) to facilitate use and be easily found.

8. Audio-video street door phone and interphone (10, 140) as in claim 6, characterized in that the internal devices (120, 130, 135, 170) fed by an independent source of electricity can be fitted onto a table support (91 , 95) to facilitate use and be easily found.

9. Audio-video street door phone and interphone (10, 140) as in claim 6, characterized that independent electric feed is supplied by batteries (122, 173) inserted in the devices (120, 130, 135, 170) .

10. Audio-video street door phone and interphone (10, 140) as in claim 6, characterized in that independent electric feed is provided by rechargeable accumulators (101 ) fitted inside the devices (85).

11 . Audio-video street door phone and interphone (10) as in claim 10, characterized in that accumulators (101 ) are recharged at a recharging set (80, 81) connected to the electricity mains (18), electric connection between accumulators (101) and the recharging set (80, 81) being automatic when the devices (85) are placed in the seat (88) made to receive them in said recharging set (80, 81).

12. Audio-video street door phone and interphone (10) as in claim 11 , characterized in that the recharging set (80) is wall-mounted.

13. Audio-video street door phone and interphone (10) as in claim 11 , characterized in that the recharging set (80) stands on a table.

14. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (130) indicate a call by means of a winker light (131).

15. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (135) indicate a call by means of a vibrator (136).

16. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (85, 120, 130, 135, 170) placed in apartment blocks (11 , 141), in single apartments or in the rooms of residential or work premises, are connected one to another as desired or to the external apparatus (50, 150) at the street door.

17. Audio-video street door phone and interphone (10,140) as in claim 16, characterized in that the internal devices (120, 130, 135, 170) present means for varying the intensity and type of sound or optical call signals so as to distinguish between those, if any, placed in the different rooms of a single residential unit (12, 13, 142, 143) and others at a place of work.

18. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (85, 120, 130, 135, 170) are of approved makes.

19. Audio-video street door phone and interphone (10,140) as in claim 1 , characterized in that the internal devices (85, 120, 130, 135, 170) comprise means for preventing cloning.

20. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (85, 120, 130, 135, 170) com- prise means for preventing wire tapping.

21 . Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the internal devices (85, 120, 130, 135, 170) are miniaturized to make them pocket size like present mobile phones.

22. Audio-video street door phone and interphone (10, 140) as in claim 1 , characterized in that the range of action of devices (85, 120, 130, 135,

170) for use inside the residential (12, 13, 142, 143) or work premises is such that they may also be used outside or nearby said primises to communicate with a visitor making a call from the external street door phone (50, 150) of the installation (10, 140).

23. Audio-video street door phone and interphone (200) as in claim 1 , characterized in that the internal devices (250) comprise a wall-mounted fixed base (251 , 286) and a mobile handset (252-255, 285), the fixed base (251 , 286) being connected to the external street door apparatus (220) by known means of wired transmission of electric signals, and to the mobile handset (252-255, 285), fed from an independent source of electricity, by electromagnetic wave transmitting and receiving devices (265,266, 277,278, 294-297, 287-299), it being thus possible to connect the handset (252-255, 285) with the external street door apparatus (220), even removing it from its base (251 , 286) and taking it outside the residential (202) and work premises as far as is permitted by the range of action established for said transmitting and receiving devices (265,266, 277,278, 294-297, 287-299).

24. Audio-video street door phone and interphone (200) as in claim 23, characterized in that the handset (252-254, 285) is fed from an independent source of electricity by accumulators (271 ,291 ) that automatically recharge when said handset (252-254, 285) is replaced on its base (251 , 286).

25. Audio-video street door phone and interphone (200) as in claim 23, characterized in that the handset (255) is fed from an independent source of electricity by batteries.

26. Audio-video street door phone and interphone (200) as in claim 23, characterized in that the handsets are adequately equipped for connec- tion to another handset in the residential or work premises through the means comprised in the external street door apparatus (220).

27. Audio-video street door phone and interphone (200) as in claim 23, characterized in that the handsets are adequately equipped for direct connection with other handsets in the residential or work premises.

28. Audio-video street door phone and interphone (200) as in claim 1 , characterized in that the electromagnetic waves are infrared rays.