WO2004037620A1

WO2004037620A1 - Device to improve defogging/defrosting function

Info

Publication number: WO2004037620A1
Application number: PCT/IT2003/000641
Authority: WO
Inventors: Antonio Giannotti
Original assignee: Antonio Giannotti
Priority date: 2002-10-25
Filing date: 2003-10-17
Publication date: 2004-05-06
Also published as: ITTO20020189U1; AU2003279565A1

Abstract

The invention is a system to improve defogging or defrosting function of a surface, by means a radiation source and a suitable substance into the material of the surface, able to absorb the radiation and release thermal energy, so to warm up quickly the surface. Because it uses electrical energy from batteries to emit radiation, this system is particularly useful into vehicles during a cold start up, when thermal energy from the engine is not immediately available.

Description

DΪSCRIPTION

Dovic* to iβφxørm ctofogging/dofrestinø function

Technical field Defrosting and defogging function are two important functions of the whole air conditioning system of a vehicle. This is particularly true during winter season, but also during humid middle seasons. Background Art In modern air conditioning systems, such a function is ensured by warm air flowing from dashboard opening near the windshield. Normally the system all the air flow available is directed to windshield. In all automatic air conditioning systems available today, equipped with a refrigerating circuit, the actions during defrost mode are:

• The compressor is inserted to remove vapour from air (at least when external temperature makes it possible)

• Switch to maximum ventilation air flow rate

• Air flows only towards the windshield ♦ The whole air flow passes through heater core, so that the air temperature is as high as possible

In modern vehicles, due to increasing efficiency of the engines, it is more and more difficult to get a heat source suitable for heating up the ambient air within the vehicle at the desired level in some critical situations (in particular, for hybrid and electrical vehicles) . So technical development in the vehicle industry is going against the possibility of quick and satisfying defogging and/or defrosting of today's vehicles' windshields or others surfaces or glasses. Disclosure

The present invention is characterised by a different way to heat up the surface with ice or fog. It is based on a source of radiation (mainly, but not exclusively, infrared radiation) . This source emitting radiation is located at the base of the surface (for example, the base of the windshield of a vehicle) . A different location should be applicable as well, provided that the emitted rays will be absorbed by the surface itself.

The electric power that is necessary for the operation of this system is supplied by the vehicle battery, so it is always available since the beginning, even in case of cold start-up.

In the glass of the windshield some filters are placed. These filters are able to absorb exclusively the radiation within the band and/or frequency range of emission of the emitters. These filters do not absorb radiation in the visible range, so that the windshield will be transparent.

The main advantages of such a system are as follows:

• It is possible to design a much smaller ventilation/air conditioning unit, since the defrost/defogging function is realised separately by a different system.

• The heating source for the windshield is available immediately, even in the first seconds after a cold start-up.

• Glass characteristics (particularly the transparency) , are not modified, Description of drawings

Figure 1 show as example of application a vehicle windshield (1). The vehicle has an air conditioning system located at (2), for warming up or cooling air to be introduced into passenger compartment. The present invention is based on radiation (typically IR radiation) emitted from (3), taking electrical energy from vehicle battery. Radiation is focused on the windshield (1), where it is absorbed and causes windshield warm up.

Figure 2 just shows how operate a mixed automatic system based on both radiation and air ventilation: the control unit UC receives analogic or digital signals (for example: water temperature of engine cooling system, air at dashboard temperature, external temperature, cabin temperature, defog sensor) . On the basis of those parameters values, it activates one or both systems for a suitable period. In other words it can activate output (a), air ventilation on/off, or (b) , radiation on/off, or (c), number of emitters on, or (d) , radiation on time.

Best way for carrying out the invention

As example, the emitting source could be an infrared one: in this case, for this application it is sufficient to use a special glass transparent to the visible light and absorbing IR radiation.

Industrial applicability

Most of glasses already used for automotive windshield already has the capacity to absorb IR radiation, while IR sources are very simple to make and low cost.

Claims

1 System for defogging/defrosting of surfaces, windshields, glasses, based on one or more radiation emitters, which are able to release radiant energy in a suitable range of frequency. The radiation is directed towards surfaces to be defrosted/defogged. These surfaces contain substances able to absorb this radiation, while visible radiation passes through.

2 System as claimed in claim 1, where the surface to be de- misted contains one or more thin layers of filters able to absorb the radiation emitted by the emitters.

3 Mixed system, based on one of the devices claimed in claim 1 or claim 2, working together with a traditional ventilation system. 4 System as claimed in claim 3, in automatic mode regulation. In this configuration, input signals come from misting-over sensors on the surface, and temperature sensors at outlet of ventilation air or engine water.

5 System as claimed in claim 1 or 2 or 3 or 4, with radiation emitters located in any possible position, upwards and/or by the side of the windshield and/or the surface to be defogged/defrosted or integrated in it.

6 System as claimed in claim 1 or 2 or 3 or 4 or 5, emitting only towards limited parts of the windshield (for example, in front of the driver) or the surface to be defogged/defrosted.

7 System as claimed in claim 1 or claim 2 that automatically operates by means a control unit, which receives as input various signals like engine water temperature, dashboard air temperature, external and internal air temperature, defog/defrost sensors.