TECHNICAL FIELD

The embodiments of the present disclosure relate to the field of optoelectronic technology, and more particularly, to a displaying system and a corresponding imaging method; and also to a vehicle including the displaying system.

BACKGROUND

A transparent displaying system typically consists of an image source and an imaging window. In existing transparent displaying systems, there are a variety of choices for the image source and the imaging window. An imaging window is usually composed of a substrate and a reflective surface, and most of the imaging windows adopt the structure in which the reflective surface serves as an interlayer in the substrate.

In the prior art, there are technical solutions utilizing a source emitting p-polarized light as the image source. For example, an imaging method using p-polarized light is mentioned in Chinese Patent Publications CN204143067U and CN104267498A, U.S. Pat. Nos. 6,952,312B2; 7,123,418B2; and 7,355,796B2, and European Patent Application EP0836108A2.

These p-polarized light based imaging methods, however, generally have the following drawbacks: if a relatively high reflectivity is required, then the transmissivity will be lowered, thereby reducing the viewing effect of the external environment, resulting in a relatively high demand on the brightness of the image source.

For example, when such methods are applied to a head-up display, a dark spot will be formed in the front window. If a relatively high transmissivity is required, the reflectivity will be lowered; in order to achieve a good imaging effect, there will be a relatively high demand on the brightness of the image source, which increases cost on power dissipation of the image source and the like.

In the prior art, a technique using a source that emits s-polarized light as the image source has been proposed. For example, U.S. Published Patent Application No. US2005012682 and Japanese Patent JP2-141720A both mention an imaging method using s-polarized light. However, such s-polarized light-based imaging methods have the following drawbacks:

1. a ghost image can be easily generated;

2. if a relatively high reflectivity is required, then the transmissivity will be reduced, thus reducing the viewing effect of the external environment.

Chinese patent CN2694293Y discloses a full color multiband stack film applied in a head-up display which utilizes the interference principle of the multi-layer film of the dielectric layer. The disadvantage of this technique is that the transmissivity of light of a specific wavelength is not high. For example, the low transmissivity for particular wavelengths such as red, green, blue light will greatly reduce the light (red, green, yellow light) emitted from traffic signal lamps, causing a potential safety hazard. Moreover, the imaging angle of the technique is limited, and the imaging effect is not good; besides, the technique requires coating about 70 layers of films, so that the manufacturing process is too complicated.

SUMMARY

A displaying system, a displaying method and a vehicle having the displaying system are provided in the technical solution of the present disclosure.

According to an embodiment of the present disclosure, a displaying system, comprises: an imaging window comprising a transparent substrate and a transflective film attached to a first surface of the transparent substrate; an image source emitting light incident on the imaging window, and the light emitted by the image source before reaching the transflective film only comprising s-polarized light. The transflective film is formed by stacking at least two types of film layers having different refractive indexes, the transflective film comprises a first side and a second side opposite to each other, the first side is attached to the first surface of the transparent substrate, the second side is in contact with the air, the second side is configured to directly reflect a first portion of the s-polarized light emitted from the image source to an observation region, and the image source and the observation region are located on a same side of the transflective film, and the transparent substrate comprises a second surface opposite to the first surface, the second surface reflects a second portion of the s-polarized light, and transmits a third portion of the s-polarized light to the air, the first portion of the s-polarized light, the second portion of the s-polarized light and the third portion of the s-polarized light are all s-polarized light.

For example, the s-polarized light emitted by the image source before reaching the transflective film has N spectral lines or bands in a visible light band, N is a positive integer not less than 1; the N spectral lines or bands each have a FWHM (full-width at half-maximum) equal to or less than 60 nm, and for each of the N spectral lines or bands in a visible spectra of the s-polarized light emitted from the image source, a major band is defined as a spectra band centered at a peak of the line or the band and expanding up to the FWHM; the transflective film reflects the s-polarized light at a first angle with respect to a normal line, and transmits ambient light at a second angle with respect to the normal line, the first angle is in a range from 30 to 89 degrees, and the second angle is in a range from 30 degrees to 80 degrees; at the first angle, the transflective film has an average reflectivity greater than 50% for at least one of the N major bands of the s-polarized light, at the second angle, the transflective film has an average transmissivity greater than 60% for p-polarized light in a visible range.

For example, the N spectral lines or bands comprise at least three spectral lines or bands, a peak position of a first spectral line or band is in a range from 410 nm to 480 nm, a peak position of a second spectral line or band is in a range from 500 nm to 565 nm, and a peak position of a third spectral line or band is in a range from 590 nm to 690 nm.

For example, the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 60%, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 60%.

For example, the peak position of the first spectral line or band is in a range from 440 nm to 460 nm, the peak position of the second spectral line or band is in a range from 530 nm to 550 nm, and the peak position of the third spectral line or band is in a range from 620 nm to 640 nm, and the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 70%, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 70%, and the transflective film has the average transmissivity greater than 95% for the p-polarized light in the visible range.

For example, the peak position of the first spectral line or band is in a range from 444 nm to 446 nm, the peak position of the second spectral line or band is in a range from 531 nm to 533 nm, and the peak position of the third spectral line or band is in a range from 634 nm to 636 nm, and the first angle is in a range from 55 degrees to 65 degrees, the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 95% at the first angle, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 95%, and the transflective film has the average transmissivity greater than 95% for p-polarized light in the visible range.

For example, the composition of each of the at least two types of film layers is at least one selected from the group consisting of tantalum pentoxide, titanium oxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride, and aluminum fluoride.

For example, an anti-reflection film is disposed on the second surface of the transparent substrate, the anti-reflection film reflects the second portion of the s-polarized light and transmits the third portion of the s-polarized light to the air; and the anti-reflection film increases an average transmissivity of the imaging window for visible light by at least 3% or more as compared with a situation where the anti-reflection film is not disposed.

For example, the s-polarized light emitted by the image source before reaching the transflective film has N spectral lines or bands in a visible light band, N is a positive integer not less than 1; the N spectral lines or bands each have a FWHM (full-width at half-maximum) equal to or less than 60 nm, and for each of the N spectral lines or bands in a visible spectra of the s-polarized light emitted from the image source, a major band is defined as a spectra band centered at a peak of the line or the band and expanding up to the FWHM; the transflective film reflects the s-polarized light at a first angle with respect to a normal line, and transmits ambient light at a second angle with respect to the normal line, the first angle is in a range from 30 to 89 degrees, and the second angle is in a range from 30 degrees to 80 degrees; at the first angle, the transflective film has an average reflectivity in a range from 25% to 50% for the N major bands of the s-polarized light; at the second angle, the transflective film has an average transmissivity greater than 60% for p-polarized light in a visible range.

According to another embodiment of the present disclosure, there is provided a vehicle comprising a displaying system as mentioned above.

For example, the s-polarized light emitted by the image source before reaching the transflective film has N spectral lines or bands in a visible light band, N is a positive integer not less than 1; the N spectral lines or bands each have a FWHM (full-width at half-maximum) equal to or less than 60 nm, and for each of the N spectral lines or bands in a visible spectra of the s-polarized light emitted from the image source, a major band is defined as a spectra band centered at a peak of the line or the band and expanding up to the FWHM; the transflective film reflects the s-polarized light at a first angle with respect to a normal line, and transmits ambient light at a second angle with respect to the normal line, the first angle is in a range from 30 to 89 degrees, and the second angle is in a range from 30 degrees to 80 degrees; at the first angle, the transflective film has an average reflectivity greater than 50% for at least one of the N major bands of the s-polarized light, at the second angle, the transflective film has an average transmissivity greater than 60% for p-polarized light in a visible range.

For example, the N spectral lines or bands comprise at least three spectral lines or bands, a peak position of a first spectral line or band is in a range from 410 nm to 480 nm, a peak position of a second spectral line or band is in a range from 500 nm to 565 nm, and a peak position of a third spectral line or band is in a range from 590 nm to 690 nm, the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 60%, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 60%.

For example, an anti-reflection film is disposed on the second surface of the transparent substrate, the anti-reflection film reflects the second portion of the s-polarized light and transmits the third portion of the s-polarized light to the air; and the anti-reflection film increases an average transmissivity of the imaging window for visible light by at least 3% or more as compared with a situation where the anti-reflection film is not disposed.

For example, the s-polarized light emitted by the image source before reaching the transflective film has N spectral lines or bands in a visible light band, N is a positive integer not less than 1; the N spectral lines or bands each have a FWHM (full-width at half-maximum) equal to or less than 60 nm, and for each of the N spectral lines or bands in a visible spectra of the s-polarized light emitted from the image source, a major band is defined as a spectra band centered at a peak of the line or the band and expanding up to the FWHM; the transflective film reflects the s-polarized light at a first angle with respect to a normal line, and transmits ambient light at a second angle with respect to the normal line, the first angle is in a range from 30 to 89 degrees, and the second angle is in a range from 30 degrees to 80 degrees; at the first angle, the transflective film has an average reflectivity in a range from 25% to 50% for the N major bands of the s-polarized light; at the second angle, the transflective film has an average transmissivity greater than 60% for p-polarized light in a visible range.

According to a further embodiment of the present disclosure, there is provided a displaying system, comprising: an imaging window comprising a transparent substrate and a transflective film attached to a first surface of the transparent substrate; an image source emitting light incident on the imaging window, and the light emitted by the image source before reaching the transflective film only comprising s-polarized light. The transflective film is formed by stacking at least two types of film layers having different refractive indexes, the transflective film comprises a first side and a second side opposite to each other, the first side is attached to the first surface of the transparent substrate, the second side is in contact with the air, the second side is configured to directly reflect the s-polarized light emitted from the image source to an observation region, and the image source and the observation region are located on a same side of the transflective film, the s-polarized light emitted by the image source before reaching the transflective film has N spectral lines or bands in a visible light band, N is a positive integer not less than 1; the N spectral lines or bands each have a FWHM (full-width at half-maximum) equal to or less than 60 nm, and for each of the N spectral lines or bands in a visible spectra of the s-polarized light emitted from the image source, a major band is defined as a spectra band centered at a peak of the line or the band and expanding up to the FWHM; the transflective film reflects the s-polarized light at a first angle with respect to a normal line, and transmits ambient light at a second angle with respect to the normal line; the first angle is in a range from 50 to 75 degrees, and the second angle is in a range from 55 degrees to 70 degrees; at the first angle, the transflective film has an average reflectivity greater than 50% for at least one of the N major bands of the s-polarized light; at the second angle, the transflective film has an average transmissivity greater than 60% for p-polarized light in a visible range.

For example, the N spectral lines or bands comprise at least three spectral lines or bands, a peak position of a first spectral line or band is in a range from 410 nm to 480 nm, a peak position of a second spectral line or band is in a range from 500 nm to 565 nm, and a peak position of a third spectral line or band is in a range from 590 nm to 690 nm, and the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 60%, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 60%.

For example, the peak position of the first spectral line or band is in a range from 440 nm to 460 nm, the peak position of the second spectral line or band is in a range from 530 nm to 550 nm, and the peak position of the third spectral line or band is in a range from 620 nm to 640 nm, and the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 70%, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 70%, and the transflective film has the average transmissivity greater than 95% for the p-polarized light in the visible range.

For example, the peak position of the first spectral line or band is in a range from 444 nm to 446 nm, the peak position of the second spectral line or band is in a range from 531 nm to 533 nm, and the peak position of the third spectral line or band is in a range from 634 nm to 636 nm, and the first angle is in a range from 55 degrees to 65 degrees, the average reflectivity of the transflective film for the three spectral lines or bands of the s-polarized light is greater than 95% at the first angle, an average transmissivity of the transflective film for the s-polarized light outside the FWHM of the three spectral lines or bands is greater than 95%, and the transflective film has the average transmissivity greater than 95% for p-polarized light in the visible range.

For example, the composition of each of the at least two types of film layers is at least one selected from the group consisting of tantalum pentoxide, titanium oxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride, and aluminum fluoride.

