A display device with screen overheat protection and a head-up display including the same

Abstract

The present invention relates to a display device (10), comprising: a liquid crystal display (LCD) screen (11) for generating an image to be displayed; a backlight device (12) for the screen (11); and a sensor (15) sensitive to infrared radiation radiated by the screen and arranged to detect at least a part of the radiation. According to the invention, the display device further comprises an electronic control unit (16), which is programmed to control the electric power (P E ) supplied to the backlight device according to an electric signal (s) provided by the sensor, such that the temperature of the screen derived from the signal is kept below a temperature threshold. The invention also relates to a head-up display provided with such a display device (10).

Description

Technical Field

[0001] The present invention relates to a display device comprising a liquid crystal display (LCD) screen for generating an image to be displayed.

[0002] The invention relates more particularly to a display device comprising, in addition to an LCD screen, a backlight for the screen, and a sensor sensitive to infrared radiation radiated by the screen, the sensor being arranged to detect at least some of this radiation.

[0003] The invention also relates to a head-up display which is equipped with such a display device and is particularly advantageously suitable for use in a vehicle, for example a motor vehicle. Background Art

[0004] It is particularly helpful for drivers of motor vehicles to be able to view information related to the operation of the vehicle, information related to the road ahead of the vehicle, and other information without having to divert their eyes from the road to do so.

[0005] To this end, it is known that a vehicle is equipped with a head-up display comprising a display device as described above. Such a head-up display is also configured to form a virtual image of the LCD screen in the driver's field of vision by reflection onto the windshield of the vehicle or by reflection onto a dedicated optical component, called a combiner, arranged between the windshield and the driver's eyes. This virtual image, including the information to be displayed, is then visually superimposed on the environment in front of the vehicle for the driver.

[0006] However, when using such a display, sunlight can enter the display in the opposite direction to the light originating from the screen and then be focused on the display. This light, together with the light from the backlighting device used for the screen, can cause a significant overheating of the screen, which may interrupt its operation or even cause irreversible damage to it.

[0007] It is then known to detect overheating of the screen with the aid of the above-mentioned sensor and, in case of overheating, to place a blackout screen in front of the LCD screen in order to protect it from the sun.

[0008] However, the information to be displayed is no longer visible to the driver. Summary of the invention

[0009] In this case, the invention proposes a display device as defined in the introduction and further comprising an electronic control unit programmed to control the electric power used to power a backlight arrangement as a function of an electric signal delivered by said sensor, such that a screen temperature derived from said signal remains below a given temperature threshold.

[0010] The device helps prevent the screen from overheating by reducing the electricity used to power the backlight without having to completely cut off the power supply. The resulting image is still visible to the user even if it is not too bright, and overheating caused by the screen's backlight is reduced.

[0011] Furthermore, the screen temperature derived from the signal transmitted by the infrared radiation sensor allows this temperature to be measured remotely and contactlessly. This therefore avoids the use of temperature sensors such as thermocouples or thermistors which need to be placed on the screen to measure its temperature and thus obscure part of the image to be displayed.

[0012] Further non-limiting and advantageous features of the display device according to the invention, considered alone or in any technically possible combination, are the following:

[0013] - the electronic control unit is programmed to: when the screen temperature derived from the signal is greater than the temperature threshold, control the backlight device to turn off;

[0014] - the electronic control unit is programmed to: when the screen temperature derived from said signal is below a temperature threshold, control the electric power used to power the backlight device so that when said screen temperature approaches the temperature threshold, the electric power is reduced;

[0015] - the electronic control unit is programmed to control said electrical power in dependence on data representative of the ambient brightness in an environment external to the display device;

[0016] - the electronic control unit is further programmed to: when the screen temperature derived from said signal is less than a limit temperature, control said electric power to a set point value independent of the screen temperature;

[0017] - the electronic control unit is programmed to: when the screen temperature derived from said signal is greater than said limit temperature and less than said temperature threshold, control said electric power so that it decreases as a function of the temperature and is below said set point value;

[0018] - the temperature threshold is a threshold above which the screen is irreversibly damaged and below which the screen is not irreversibly damaged;

[0019] - The temperature threshold is in the range of 110°C to 130°C;

[0020] - the limit temperature is in the range of 70 degrees Celsius to 100 degrees Celsius;

[0021] - the sensor is sensitive to infrared radiation of at least one wavelength in the range of 6 micrometers to 14 micrometers;

[0022] The display device further comprises a filter arranged between the screen and the sensor on the path followed by said infrared radiation, the value of the transmission coefficient of the filter for the wavelength in the range of 6 micrometers to 14 micrometers being greater than the average value of the transmission coefficient in the visible light range.

[0023] The present invention also relates to a head-up display comprising the display device as described above.

[0024] Further non-limiting and advantageous features of the head-up display according to the invention, considered individually or in any technically possible combination, are as follows:

[0025] - the display comprises a housing having an exit hole, the screen and the sensor being located in the housing, the visible light emitted by the screen being used to display the image leaving the housing via the exit hole;

[0026] - the display further comprises a conduit extending from the LCD screen to the exit hole of the housing, a side hole being formed in a side wall of the conduit, and the sensor being arranged outside the conduit and retracted relative to the side wall;

[0027] - the sensor is arranged opposite to the screen relative to the side hole;

[0028] - said portion of the infrared radiation detected by the sensor passes through the side hole of the catheter before reaching the sensor;

[0029] - the side hole is closer to the screen than the exit hole of the housing;

[0030] - the sensor is arranged at the bottom of the cavity defined by the wall;

[0031] - said cavity is revealed in the catheter via said side hole;

[0032] - the wall of the cavity is connected to said side wall of the conduit;

[0033] - on the side of the side hole opposite to the screen, the wall of the cavity and said side wall are connected together by forming an acute angle together;

[0034] - the light generated by the backlight device leaves the screen in the form of a beam centered on a mean emission axis; the measurement axis connecting the sensor to the screen deviates from the mean emission axis by an angle exceeding 30 degrees;

[0035] - the display further comprises a reflector arranged to reflect visible light emitted by the screen as it travels from the screen to the exit aperture of the housing, the reflector being at least partially transparent to said infrared radiation detected by the sensor, said visible light being reflected from one side of the reflector and the sensor being located on the other side of the reflector;

[0036] - said portion of the infrared radiation detected by the sensor passes through the reflector before reaching the sensor;

[0037] - said filter is produced by said reflector;

[0038] - the sensor is located outside the glare zone, which is the area that will be covered by infrared radiation entering the housing through its exit aperture, the propagation direction of which is opposite to the direction in which visible light leaves the housing;

[0039] The glare zone covers the entire area within the housing that is exposed to omnidirectional infrared radiation coming from outside the housing and entering the housing through its exit aperture. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The following description, made with reference to the accompanying drawings, provided as non-limiting examples, will facilitate the understanding of the invention and how it can be produced.

[0041] In the attached figure:

[0042] Figure 1 Schematically shows a side view of a heads-up display according to a first embodiment of the teachings of the present invention;

[0043] Figure 2 schematically illustrates a side view of a heads-up display according to a second embodiment of the teachings of the present invention; and

[0044] Figure 3 Schematically shows the Figure 1 The electrical power used to power the backlight of a display varies with the temperature of the LCD screen of the display. DETAILED DESCRIPTION

[0045] Figure 1 and 2 Two exemplary embodiments 1 ; 1 ′ of a head-up display 1 are shown, which are mounted on a vehicle, such as a car, a boat, a tram or a bus.

[0046] In each of these embodiments, the display 1; 1' comprises display means 10; 10' comprising a liquid crystal display (LCD) screen 11. This screen allows the generation of an image to be displayed.

[0047] The display device 10; 10' further comprises an infrared radiation sensor 15 for remotely measuring the temperature of the screen 11 in order to detect possible overheating thereof.

[0048] Figure 1 and 2 The main difference between the two embodiments shown in each case relates to the positioning of the sensor 15 .

[0049] Therefore, in different drawings, identical or similar elements in the two embodiments will be given the same reference numerals as much as possible and will not be described every time.

[0050] The display device 10; 10' itself will be described first, and the overall structure of the display 1; 1' on which it is mounted will be described later.

[0051] In each of these embodiments, the display device 10 ; 10 ′ comprises, in addition to the screen 11 and the sensor 15 , a backlight device 12 for the LCD screen 11 .

[0052] The backlight device 12 comprises a light source 13 , for example generated by a light emitting diode. It may also comprise a reflector 14 , which is configured to direct the visible light generated by the light source 13 to the screen 11 .

[0053] The light source 13 is supplied with electric power P E These electronic power components are controlled by the electronic control unit 16, thereby controlling the electric power P supplied to the light source 13. E As a variant, the control unit can integrate the aforementioned electronic power components.

[0054] As previously mentioned, the sensor 15 fitted to this display device 10 ; 10 ′ allows remote, contactless measurement of the temperature of the screen 11 , based on the infrared radiation radiated by the screen 11 .

[0055] This infrared radiation is of the thermal type. Taking into account the heat source of infrared radiation and the temperature of the screen, the power of this radiation is mainly contained in the wavelength range of 1 micron to 15 microns. Since the temperature of the screen is actually in the range of about -40 degrees Celsius to 140 degrees Celsius, most of the thermal radiation power is more specifically in the range of 6 microns to 14 microns.

[0056] The sensor 15 is sensitive to at least some of the infrared radiation radiated by the screen 11. Thus, the sensor 15 is sensitive to infrared radiation within a wavelength range that, for example, covers at least some of the wavelength range of 6 micrometers to 14 micrometers. In this case, in the embodiment described here, the sensor 15 is sensitive to infrared radiation within a wavelength range of 5.5 micrometers to 14 micrometers. Within the wavelength range that the sensor 15 is sensitive to, it transmits an electrical signal s , the electrical signal s depends on the power of the infrared radiation received by the sensor 15. s represents the power of the infrared radiation received by the sensor 15 in the wavelength range.

[0057] The sensor 15 may be generated, for example, by a pyrometer comprising a thermopile or by a photodiode.

[0058] The control unit 16 is programmed to: based on the signal transmitted by the sensor 15 s to determine the temperature T of the screen 11.

[0059] Notably, the control unit 16 is also programmed to: according to the electrical signal transmitted by the sensor 15 s to control the electric power P for powering the backlight device 12 E (i.e., in this case, the electric power P for powering the light source 13 E ), such that the temperature T of the screen 11 derived from this signal s is maintained below a given temperature threshold T 1 .

[0060] Therefore, with this device, in the case of overheating of the screen 11, the electric power P for powering the backlight device 12 can be reduced E , without having to completely cut off the power supply. This helps prevent overheating and at the same time preserves the visible image for the user (even if it is not very bright).

[0061] The electronic control unit 16 is more specifically programmed to:

[0062] - When the temperature T of the screen derived from the signal s is greater than the temperature threshold T 1 , control the backlight device 12 to turn off, i.e., control the electric power P E to make it zero; and

[0063] - When the temperature T is less than the temperature threshold T 1 , control the electric power P for powering the backlight device 12 E , such that when the temperature T approaches the temperature threshold T 1 , the electric power P E is reduced.

[0064] Therefore, before the temperature threshold T 1 is reached, the electric power P E is reduced in a certain way, thus allowing prediction of screen overheating. This gradual moderation of the electric power allows avoidance of the turning off of the backlight device 12, or, if such turning off cannot be avoided, allows delay of the turning off, thereby making the generated image remain visible to the user for a longer time.

[0065] The temperature threshold T 1 is such a threshold: when exceeding this threshold, the screen 11 is irreversibly damaged, and when below this threshold, the screen 11 is not irreversibly damaged. This depends on the model of the liquid crystal display screen used, and in this case, the temperature threshold is in the range of 110 degrees Celsius to 130 degrees Celsius.

[0066] like Figure 3 As shown, the electronic control unit 16 is programmed to:

[0067] -When the screen temperature T is lower than the limit temperature T 2 When the electric power P is controlled independently of the screen temperature T E , so that it reaches the set point value P E,o ;as well as

[0068] - When the screen temperature T is greater than the limit temperature T 2 And is less than the temperature threshold T 1 When the control electric power P E , making it less than the set point value P E,o And it decreases with the temperature T.

[0069] The electronic control unit 16 can be programmed, for example, so that at the limit temperature T 2 and temperature threshold T 1 In the temperature range between E Depending on the temperature T, for example, in a precise manner, from the set point value P E,o (For T = T 2 ) continuously decreases to zero (for T = T 1 Within this temperature range, the electronic control unit 16 can be programmed, for example, to set the set point value P E,o Multiply by a coefficient between 0 and 1 to determine the power P that can be controlled E The value of , which decreases with the temperature T.

[0070] The electronic control unit 16 is also programmed to determine the set point value P according to data representative of the ambient brightness in the environment E outside the display device. E,o The set point value is determined, for example, in such a way that the greater the brightness in the environment E, the greater the set point value. This setting allows the image projected in the driver's visual environment to be bright enough relative to the environment so that the image is visible to the user even when the environment is very bright. This also allows avoiding unnecessary lighting of the screen 11 at full power when the ambient brightness in the environment is low.

[0071] In this case, the temperature threshold T 1 It can be in the range between 110 degrees Celsius and 130 degrees Celsius. The electrical power P E From the limit temperature T 2 The limit temperature T 2 , which in the specific example described here is, for example, in the range between 70 degrees Celsius and 100 degrees Celsius.

[0072] It should be noted that the electrical power P E represents, for example, the average value of the instantaneous electric power supplied to the backlight device 12 in a time period between 0.1 seconds and 5 seconds. Therefore, the electric power P can be adjusted as follows E For example:

[0073] - by controlling the value of this instantaneous electrical power (particularly in the case of directly powering the backlight device 12); and / or

[0074] - by alternating the power P of the backlight 12 with a high frequency (e.g., greater than 100 Hz) and an adjustable duty cycle adjustable between 0% and 100% E .

[0075] The overall structure of a display 1; 1' equipped with the display device 10; 10' is now shown in more detail.

[0076] The display 1; 1 ' comprises an optical projection system configured to project visible light emitted by the screen 11 onto a partially transparent strip 7, in this case produced by the windshield of the vehicle. The strip 7 then reflects the received light towards the eyes 8 of the vehicle driver. By virtue of the transparent properties, the driver can thus observe the environment of the vehicle through the strip 7 and at the same time observe a virtual image of the screen 11 formed in that environment by the strip 7 and the optical projection system.

[0077] In the example shown in the drawings, the optical projection system comprises a first reflector 5; 5' and a second reflector 6. The first reflector 5; 5' is arranged to reflect visible light emitted by the screen 11 towards the second reflector 6. The second reflector 6, which is concave in this case, is arranged to reflect light from the first reflector 5; 5' towards the strip 7.

[0078] As a variant, the optical projection system may comprise other optical components or may even be omitted (in which case the screen is arranged to emit said light directly towards the partially transparent strip).

[0079] The display 1; 1' further comprises a housing 2 defined by an outer wall 3, in which an exit aperture 4 of the housing is formed. Visible light emitted by the screen 11 leaves the housing 2 via the exit aperture 4 and towards the partially transparent strip 7.

[0080] The display 1; 1 ' also comprises a duct 20; 20' which extends from the LCD screen 11 to the exit aperture 4. In this case, the duct comprises a first, generally tubular portion which extends from the screen 11 to the vicinity of the first reflector 5; 5'. The duct also comprises a second portion connected to the first portion in the vicinity of the first reflector 5; 5' and which extends to the exit aperture 4. The walls of the duct 20; 20' forming these generally tubular first and second portions are opaque. This therefore allows guiding the light emitted by the screen 11 through the inner space of the duct 20; 20' which is defined by the walls of these first and second portions.

[0081] The infrared radiation sensor 15 is placed outside the duct 20; 20', i.e. outside this internal space. This therefore prevents the sensor from receiving visible light emitted by the screen. This arrangement, in the same way as the presence of the filter 17 placed in front of the sensor 15 to eliminate residual visible light that could reach this sensor, contributes to improving the reliability of the screen temperature measurement performed by means of the sensor.

[0082] In the first embodiment ( Figure 1 ), the infrared radiation sensor 15 is placed near the screen 11, closer to the screen than the exit hole 4. Then, the side hole 22 formed in the side wall 21 of the duct 20 allows some of the infrared radiation radiated by the screen 11 to reach the sensor 15 (this infrared radiation is emitted in a practically omnidirectional manner).

[0083] The sensor 15 is more specifically arranged such that:

[0084] - Average emission axis X E The visible light emitted by the screen 11 is centered on the average emission axis X E as the center; and

[0085] -Measurement axis X M , which connects the center of the sensor 15 to the center of the screen 11,

[0086] Separated from each other by an angle α greater than 30 degrees.

[0087] This off-axis position of the sensor 15 prevents it from receiving visible light from the screen 11 .

[0088] Furthermore, due to the use of the reflector 14, the infrared radiation radiated by the light source 13 of the backlight 12 is also emitted behind the screen 11 in a direction approximately parallel to the average emission axis X. E And take the average emission axis X E Therefore, the off-axis position of the sensor 15 also prevents the infrared radiation emitted by the light source 13 from reaching the sensor 15. Therefore, the reliability of the temperature measurement of the screen 11 obtained by the sensor 15 is improved.

[0089] The sensor 15 is set back relative to the side wall 21 creating the lateral aperture 22, occupying the bottom of a cavity 23 defined by an opaque wall 24. This wall 24 protects the sensor from any stray radiation that may be present in the housing 2.

[0090] On the side of the side hole 22 opposite to the screen 11, the wall 24 of the cavity 23 and the side wall 21 are connected together by forming an acute angle β, for example in the range between 20 and 60 degrees. In the area where the wall 24 of the cavity 23 and the side wall 21 are connected by forming an acute angle β, these walls thus form a kind of overhang interposed between the sensor 15 and the interior of the conduit 20. This overhang prevents visible light or infrared radiation coming from the outside of the housing 2 and entering the housing via the exit hole 4 from reaching the sensor 15.

[0091] More generally, in this case, the sensor 15 is located in the first glare zone Z E In addition, the first dazzling area Z E is the area covered by the infrared radiation that enters the housing 2 through the exit hole 4 of the housing 2, and the propagation direction of the infrared radiation is opposite to the direction in which the visible light leaves the housing 2. Assuming that the first and second reflectors 5 and 6 are reflective in the infrared band, then Figure 1 The first glaring area Z indicated by the shadow E In this case, the entire interior of the catheter 20 is covered, but the cavity 23 accommodating the sensor 15 is not covered.

[0092] The display 1 also comprises the aforementioned filter 17 arranged between the screen 11 and the sensor 15 and having a greater transmission coefficient for infrared radiation, to which the sensor 15 is sensitive, than for visible light. Figure 1 In FIG. 1 , the optical filter 17 and the sensor 15 are shown as being separated from each other. The optical filter 17 can still be integrated in the sensor 15. The optical filter 17 is a filter as described below:

[0093] the first transmission value of the filter, equal to the average value of its transmission coefficient in the wavelength range to which the sensor 15 is sensitive (in this case, as a reminder, the wavelength range from 5.5 microns to 14 microns), is greater than

[0094] - a second transmission value of the filter, equal to the average value of its transmission coefficient in the visible range.

[0095] For example, the first transmission value is greater than 40%, or even greater than 60%. As for the second transmission value, for example, it is less than 10%.

[0096] In the second embodiment ( Figure 2), the sensor 15 is not laterally offset relative to the mean emission axis, but is placed in the extension of this axis. However, it is then placed behind a first reflector 5' which is at least partially transparent in the above-mentioned wavelength range to which the sensor 15 is sensitive.

[0097] This reflector 5' is reflective in the visible range and in particular fulfills the role of the filter 17 described above: it allows the sensor 15 to receive a portion of the infrared radiation radiated by the screen 11, while preventing the visible light originating from the screen 11 from reaching the sensor 15. Thus, the reflectance of the first reflector 5' has an average value in the visible range and at the incidence at which it is used, for example, greater than 60%, or even greater than 80% (this reflectance can be obtained, for example, by a thin reflective layer deposited on one of the faces of the first reflector 5'). As for the average value of its transmission coefficient, for example, in the wavelength range to which the sensor 15 is sensitive, this average value is greater than 40%, or even greater than 60%. For example, the substrate of the first reflector 5' can be made of silicon or germanium.

[0098] The sensor 15 is placed opposite the screen 11 with respect to the first reflector 5'. The sensor 15 is also placed at the bottom of a cavity 23' defined by a wall 24'. The wall 24' extends from the sensor 15 to the first reflector 5'.

[0099] Furthermore, in this second embodiment, the sensor 15 is located in the second glare zone Z' E In a manner similar to the first embodiment, in this case, the second glare zone Z' E The area covered by the infrared radiation entering the housing 2 through the exit hole 4 of the housing 2, the propagation direction of the infrared radiation is opposite to the direction in which the visible light leaves the housing 2 (in Figure 2 Assuming that the second reflector 6 is reflected in the infrared band, the second glaring area Z' E The second glare zone Z' covers the inner space of the second part of the conduit 20 and extends behind the first reflector 5', because the reflector is partially transparent in the infrared band. Behind the first reflector 5', that is, on the side of the reflector opposite to the screen 11, the second glare zone Z' E The region R extending from the first reflector 5' is occupied as an extension of the axis connecting the second reflector 6 to the first reflector 5' ( Figure 2 ). The sensor 15 is placed outside this area. Therefore, this advantageously prevents the possibly strong infrared radiation from the sun from reaching the sensor 15.

[0100] Furthermore, the sensor 15 may integrate a filter (not shown) similar to the filter of the first embodiment and which prevents residual visible light that may have passed through the first reflector 5 ′ from reaching the sensitive surface of the sensor.

[0101] In a variation of this second embodiment, the infrared radiation sensor may be placed behind the second reflector, on a side of the second reflector opposite to the first reflector. In this variation, the second reflector is at least partially transparent in the above-mentioned wavelength range to which the infrared radiation sensor is sensitive.

Claims

1. A head-up display (1 ； 1'), including: A display device (10; 10') comprising: a liquid crystal display (LCD) screen (11) for generating an image to be displayed; a backlight device (12) for the screen (11); a sensor (15) sensitive to infrared radiation radiated by the screen (11) and arranged to detect at least some of the radiation, characterized in that the display device (10; 10') also comprises an electronic control unit (16) programmed to control the electric power (PE) used to power the backlight device (12) according to the electric signal (s) delivered by the sensor (15), so that the temperature (T) of the screen derived from the signal (s) is kept below a given temperature threshold (T1); and A housing (2) having an exit hole (4), the screen (11) and the sensor (15) being located in the housing (2), and the visible light emitted by the screen (11) being used to display the image leaving the housing (2) via the exit hole (4), The head-up display further comprises a reflector (5'), the reflector (5') being arranged to reflect visible light emitted by the screen (11) as it travels from the screen (11) to the exit hole (4) of the housing (2), the reflector (5') being at least partially transparent to the infrared radiation detected by the sensor (15), the visible light being reflected from one side of the reflector (5'), and the sensor (15) being located on the other side of the reflector (5'), or the head-up display (1; 1') comprising a duct (20; 20'), the duct (20; 20') extending from the liquid crystal display (LCD) screen (11) to the exit hole (4) of the housing (2), a side hole (22) being formed in a side wall (21) of the duct (20), and wherein the sensor (15) is arranged outside the duct (20) and retracted relative to the side wall (21).

2. A head-up display (1; 1') according to claim 1, in, The electronic control unit (16) is programmed to: when the temperature (T) of the screen derived from the signal (s) is greater than the temperature threshold (T1), control the backlight device (12) to turn off; and when the temperature (T) of the screen derived from the signal (s) is less than the temperature threshold (T1), control the electric power (PE) used to power the backlight device (12) so that when the temperature (T) approaches the temperature threshold (T1), the electric power (PE) decreases.

3. A head-up display (1; 1') according to claim 2, in, The temperature threshold (T1) is a threshold value: when the temperature exceeds the threshold value, the screen (11) is irreversibly damaged, and when the temperature is below the threshold value, the screen (11) is not irreversibly damaged.

4. A head-up display (1; 1') according to claim 1 or 2, in, The sensor (15) is sensitive to infrared radiation of at least one wavelength in the range of 6 micrometers to 14 micrometers.

5. A head-up display (1; 1') according to claim 4, in, The display device also includes a filter (17; 5'), which is arranged on the path followed by the infrared radiation between the screen (11) and the sensor (15), wherein the value of the transmission coefficient of the filter (17; 5') for wavelengths in the range of 6 micrometers to 14 micrometers is greater than the average value of the transmission coefficient in the visible light range.

6. The head-up display (1; 1') according to claim 1, in, The sensor (15) is arranged at the bottom of a cavity (23) defined by a wall (24) which emerges in the catheter (20) via the side hole (22).

7. A head-up display (1; 1') according to claim 5, in, The optical filter is produced by means of the mirror (5').

8. A head-up display (1; 1') according to claim 1 or 2, in, The sensor (15) is located outside a glare zone (ZE; Z'E), which is an area covered by infrared radiation entering the housing (2) through an exit hole (4) of the housing (2), and the propagation direction of the infrared radiation is opposite to the direction in which the visible light leaves the housing (2).

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