Lighting system and projection device

Abstract

The application relates to an illumination system and a projection device, the illumination system comprising a light source, a lens, an optical functional device and a filter film, the light source being used for emitting light, the lens being arranged on the light emitting side of the light source, the lens comprising an incident surface facing the light source and an emitting surface opposite to the incident surface, the optical functional device being arranged on the light emitting side of the lens, the optical functional device comprising an illumination surface facing the emitting surface, the filter film being arranged between the optical functional device and the lens, the transmittance distribution of the filter film satisfying certain conditions, so that the light spectrum of the light irradiated on each point of an illumination surface through the lens and the filter film is consistent. The application can adjust the lens surface type, reduce the color difference between the center and the periphery of a picture formed through the illumination system, and improve the color uniformity of the image formed by the projection device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of projection technology, in particular to an illumination system and a projection device. BACKGROUND

[0002] A single-chip LCD projection device refers to a projection product that uses a single transmissive LCD panel to modulate light emitted by an optical module to form an image, and then enlarges and projects the image on a projection area through a projection lens. Compared with other types of projection devices, such as DLP or LCoS, a single-chip LCD projection device is low in price and simple to manufacture.

[0003] An illumination system of a projection device in the related art uses a lens to diffuse light emitted by a light source. However, the optical path of light in the lens varies with the position and angle of the light-emitting point. In addition, the absorption coefficients of the lens medium for different wavelengths are different. Therefore, the color coordinates of the same spectrum after passing through different optical paths are different, that is, the color is not uniform, which is not conducive to improving the color uniformity of the illumination system and the display effect of the projection device. SUMMARY

[0004] Therefore, the present application provides an illumination system and a projection device to improve the color uniformity of the illumination system and the display effect of the projection device.

[0005] According to an aspect of the present application, an illumination system is provided, which comprises:

[0006] a light source configured to emit light;

[0007] a lens disposed on the light-emitting side of the light source, the lens comprising an incident surface facing the light source and an emitting surface opposite to the incident surface;

[0008] an optical functional device disposed on the light-emitting side of the lens, the optical functional device comprising an illumination surface facing the emitting surface; and

[0009] a filter film disposed between the optical functional device and the lens;

[0010] The transmittance distribution of the filter film satisfies:

[0011] ;

[0012] ;

[0013] ;

[0014] wherein, T(x) is the transmittance of the filter film, T(0) is the transmittance of the filter film at the center axis, , , is the intensity of the light emitted by the light source, is the exit angle of the light on the light source, is the normalized spectrum of the light source, is the spectrum of the light source at the optical axis, λ is the wavelength of the light, D is the diameter of the lens, e is the distance between the optical axis of the lens and the illumination surface, a is the absorption coefficient of the medium of the lens, h is the distance between the incident position of the light on the illumination surface and the optical axis, x0 is the distance between the exit position of the light on the exit surface and the light source in the direction parallel to the optical axis, y0 is the distance between the exit position of the light on the exit surface and the light source in the first direction, x1 is the distance between the incident position of the light on the entrance surface and the light source in the direction parallel to the optical axis, y1 is the distance between the incident position of the light on the entrance surface and the light source in the first direction; the optical axis and the first direction are perpendicular to each other.

[0015] In one of the embodiments, the optical functional device comprises a liquid crystal layer or a collimating lens, and the side of the liquid crystal layer or the collimating lens facing the lens is the illumination surface, and the filter film is coated on the illumination surface.

[0016] In one of the embodiments, the filter film comprises a multilayer film structure coated on the illumination surface.

[0017] In one of the embodiments, the materials and / or thicknesses of the at least two layers of the film structure are different.

[0018] In one of the embodiments, the thicknesses and / or surface shapes of at least two different positions of the filter film are different.

[0019] In one of the embodiments, the entrance surface of the lens is convex, the exit surface of the lens is convex, and the lens comprises a lens with positive focal power.

[0020] In one of the embodiments, the light source comprises a light emitting chip, and the light emitting chip is configured to emit light with adjustable intensity; and / or,

[0021] The light source comprises a plurality of light emitting regions, and each light emitting region comprises a plurality of light emitting chips arranged in an array, and the light emitting chips in different light emitting regions can be independently adjusted.

[0022] In one of the embodiments, the side of the light source facing the lens is coated with phosphor, and the thicknesses and / or surface shapes of the phosphor at different positions on the light source are different.

[0023] In one of the embodiments, the normalized spectrum of the light source satisfies:

[0024] ;

[0025] .

[0026] According to another aspect of the present application, a projection device is provided, comprising the above-mentioned illumination system.

[0027] The above-mentioned illumination system and projection device, by means of the spectral integration of the light ray at a point on the illumination surface related to the lens diameter, the distance between the lens and the illumination surface, the absorption coefficient of the medium of the lens, and the distance between the lens and the light source, in combination with the transmittance of the filter film, the condition that the distribution of the transmittance of the filter film needs to satisfy if the color uniformity of the illumination system is to be improved is derived, so that the appropriate transmittance of the filter film can be selected or set according to the condition to improve the color uniformity of the illumination system, which is conducive to improving the display effect of the projection device. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the absorption spectrum of the medium.

[0029] Figure 2 is a structural schematic diagram of the illumination system of the present application.

[0030] Figure 3 is the optical path diagram of the light ray in the illumination system of the present application.

[0031] BRIEF DESCRIPTION OF DRAWINGS

[0032] 10, illumination system;

[0033] 100, light source; 200, lens; 210, light entrance surface; 220, light exit surface; 300, illumination surface; 400, Fresnel lens; 500, filter film;

[0034] F1, first direction. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below in combination with the drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0036] In the description of the application, it should be understood that, if there are these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0037] In addition, if there are these terms "first", "second", these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0038] In this application, unless otherwise explicitly specified and limited, if there are terms such as "mounting", "connecting", "connecting", "fixing" and the like, these terms should be broadly understood. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0039] In this application, unless otherwise explicitly specified and limited, if there are similar descriptions such as "first feature on or under second feature", the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0040] It is to be noted that when an element as claimed in the application is referred to as being "on" or "connected to" another element, it can be directly on the other element or intervening elements can be present. When used in the application, the terms "vertical", "horizontal", "up", "down", "left", "right", and the like are made only with respect to the drawings as posited and not meant to be limiting.

[0041] When light propagates in a medium, the bound electrons in the medium are forced to oscillate under the action of the electric field of the light wave. This is equivalent to the light wave consuming energy to excite the oscillation of the electrons. Part of this energy is added to the incident wave in the form of secondary waves to form the transmitted light wave and exit the medium. In addition, due to the interaction with the surrounding atoms and molecules, part of the energy of the forced oscillation of the bound electrons is converted into other forms of energy, such as the energy of molecular thermal motion. This part of the energy loss is what we refer to as the absorption of light by the medium.

[0042] The absorption of the medium can be described by introducing a complex refractive index. If the refractive index of the absorbing medium is:

[0043] ;

[0044] The electric field of the plane wave propagating in the medium along the direction of the light ray can be written as:

[0045] ;

[0046] The intensity of the plane wave is:

[0047] ;

[0048] where I0=|A| 2 is the light intensity at z=0, i.e., the light intensity at a distance of 0 in the medium, and α=2nkw / c is called the absorption coefficient of the absorbing medium. The above equation is the Lambert-Beer law, which shows that the intensity of the light wave decays exponentially with the distance of propagation in the medium, and the speed of decay depends on the absorption coefficient of the material.

[0049] Most materials have wavelength selectivity in the absorption of visible light. The selectivity of the absorption of a material can be represented by the relationship curve of their absorption coefficient and wavelength, as shown in Figure 1 In a certain wavelength range, the absorption of the material is very strong, and there is a maximum value. This absorption range is called the absorption band. In a projection system, the absorption of different wavelengths by the illumination system is one of the main reasons for the color deviation of the picture from the designed value.

[0050] There are two common liquid crystal display (LCD) lighting systems: a light cone lighting system and a lens lighting system. For the lens system, the optical path of the light in the lens is different with the position and angle of the light emitting point, and the absorption coefficient of the lens medium for different wavelengths is different, so the color coordinates of the same spectrum after passing through different optical paths will be different, that is, the color unevenness phenomenon occurs.

[0051] Based on the above problems, the application provides a lighting system 10 and a projection device, which can reduce the color difference between the center and the periphery of the picture formed by the lighting system 10 of the application by setting or selecting the filter film 500 of the application, and select or set the appropriate transmittance of the filter film 500 for the incident light at different positions, thereby improving the color uniformity of the image formed by the projection device.

[0052] The lighting system of the application can be a projection light machine or any other suitable lighting system for lighting or projection, that is, the lighting system of the application is suitable for lighting systems for various types of projection, including commercial lighting, engineering lighting, and consumer lighting.

[0053] Referring to FIGS. 1, 2, and 3, Figure 2 and Figure 3 The lighting system 10 provided by the application includes a light source 100, a lens 200, an optical functional device, and a filter film 500. The light source 100 is used to emit light, the lens 200 is arranged on the light emitting side of the light source 100, the lens 200 has an incident surface 210 facing the light source 100 and an emitting surface 220 opposite to the incident surface 210, the optical functional device is arranged on the light emitting side of the lens 200, the optical functional device has an illumination surface 300 facing the emitting surface 220, and the filter film 500 is arranged between the optical functional device and the lens 200. The transmittance distribution of the filter film 500 satisfies:

[0054] Formula One

[0055] Formula Two

[0056] Formula Three

[0057] Wherein, is the transmittance of the filter film 500, is the transmittance of the filter film 500 at the center,

[0058] , , is the light intensity emitted by the light source 100, is the exit angle of the light on the light source 100, The normalized spectrum of the light source 100 is the normalized spectrum of the light source 100 in the spectral data analysis, which is mainly to eliminate the influence of different signal intensities at different wavelengths. Therefore, the data often needs to be normalized in spectral analysis.

[0059] is the spectrum of the light source 100 at the optical axis, λ is the wavelength of the light, D is the diameter of the lens 200, e is the distance between the axis of the lens 200 and the illumination surface 300, α is the absorption coefficient of the medium of the lens 200, h is the distance between the incident position of the light on the illumination surface 300 and the optical axis, x0 is the distance between the exit position of the light on the light exit surface 220 and the light source 100 in the direction parallel to the optical axis, y0 is the distance between the exit position of the light on the light exit surface 220 and the light source 100 in the first direction F1, x1 is the distance between the incident position of the light on the light incident surface 210 and the light source 100 in the direction parallel to the optical axis, y1 is the distance between the incident position of the light on the light incident surface 210 and the light source 100 in the first direction F1, and the optical axis and the first direction F1 are perpendicular to each other.

[0060] When the filter film 500 satisfies the above-mentioned Formulas 1, 2, and 3, the spectra of the light rays irradiated to each point on the illumination surface 300 through the lens 200 and the filter film 500 are the same, the color uniformity of the light spot on the illumination surface 300 is high, the color difference between the center and the periphery of the image formed by the illumination system 10 of the present application is reduced, and the color uniformity of the image formed by the projection device of the present application is better.

[0061] It is understood that the transmittance of the filter film 500 may be different at different locations. The transmittance of the light at the incident position of the filter film 500 satisfies the following relationship: the distance between the exit position of the light on the light exit surface 220 and the light source 100 in a direction parallel to the optical axis is x0; the distance between the exit position of the light on the light exit surface 220 and the light source 100 in the first direction F1 is y0; the distance between the incident position of the light on the light incident surface 210 and the light source 100 in a direction parallel to the optical axis is x1; and the distance between the incident position of the light on the light incident surface 210 and the light source 100 in the first direction F1 is y1. In other words, the light incident at different positions and the transmittance of the light by the filter film 500 satisfy the above relationship. That is, the light incident at different positions corresponds to different positions on the light exit surface 220 and the light incident surface 210. Correspondingly, the distance e between the axis of the lens 200 and the illumination surface 300 may also be different. Furthermore, the angle between the light incident on the illumination surface 300 and the illumination surface 300, or the angle of incidence of the light on the light source 100, is At the same time, the transmittance of the light filtering film 500 to the light still satisfies the above relationship. That is, corresponding to the setting of the different illumination system 10, the light filtering film 500 can be set correspondingly, the local transmittance of the light filtering film 500 is adjusted, so that the transmittance of the light filtering film 500 to the light still satisfies the above relationship, so that the spectrum of the light irradiated to each point on the illumination surface 300 through the lens 200 and the light filtering film 500 is the same.

[0062] As Figure 3 In the illumination system 10, the light emitted by the light source 100 is irradiated to the illumination surface 300 after passing through the lens 200 and the light filtering film 500. The light incident to a point on the illumination surface 300 is converged and integrated by the light emitted by different points on the light source 100 at different angles. Since the optical path of the light passing through the lens 200 is inconsistent at different points on the illumination surface 300, and the absorption rate of the lens 200 to light of different wavelengths is different, the color of the light spot on the illumination surface 300 will be uneven.

[0063] Suppose a light is emitted from a point on the light source 100, and then irradiated to a point on the illumination surface 300 at an angle of θ after passing through the lens 200 and the light filtering film 500. Taking the intersection of the light emitted by the light source 100 and the optical axis as the origin, and taking the optical axis as the x-axis and the axis parallel to the first direction F1 as the y-axis, the propagation of the light between the lens 200 and the illumination surface 300 can be simulated as a straight line L1 in the coordinate system. The straight line L1 can be expressed as:

[0064] Formula four;

[0065] Wherein, in the axial direction along the optical axis, a is the distance from the light source 100 to the light entrance surface 210 of the lens 200, b is the distance from the light exit surface 220 of the lens 200 to the illumination surface 300, d is the thickness of the lens 200, and a+b+d is the distance from the light source 100 to the illumination surface 300.

[0066] Suppose the light exit surface 220 of the lens 200 conforms to: y=g(x) …… Formula five;

[0067] Then, the coordinates of the intersection B of the light and the light exit surface 220, and the angle between the light emitted from the light exit surface 220 and the normal direction of the light exit surface 220 can be obtained from Formula four and Formula five. Figure 3 The value (see the mark in

[0068] B(x0, y0);

[0069] ;

[0070] According to the refraction law, we have:

[0071] ​ ;

[0072] ;

[0073] wherein, is the angle between the light ray and the normal direction of the light exit surface 220 in the lens 200, and n is the refractive index of the lens 200. According to the above formula, the angle between the light ray and the normal direction of the light exit surface 220 in the lens 200 and the angle between the light ray exiting the light exit surface 220 and the normal direction of the light exit surface 220 .

[0074] The propagation of the light ray in the lens 200 is simulated as a straight line L2 in the coordinate system. Let the slope of the straight line L2 be k2, then k2 satisfies:

[0075] Formula Six.

[0076] According to the above formula, the angle between the light ray and the normal direction of the light exit surface 220 in the lens 200 and the slope k2 of the straight line L2. Meanwhile, the above formula also shows the relationship between the angle between the light ray and the normal direction of the light exit surface 220 in the lens 200 and the surface shape g(x) of the light exit surface 220 of the lens 200.

[0077] The straight line L2 is:

[0078] Formula Seven.

[0079] Suppose the surface shape of the light entrance surface 210 of the lens 200 satisfies: Formula Eight.

[0080] Then, according to Formula Seven and Formula Eight, the coordinates of the intersection point A of the light ray and the light entrance surface 210 can be recorded as: ;

[0081] And according to the slope k2 of the straight line L2 and the surface shape (Formula Eight) of the light entrance surface 210 of the lens 200, we can get

[0082] ;

[0083] wherein, is the angle between the light ray and the normal direction of the light entrance surface 210 in the lens 200. According to the above formula and Formula Six, the angle between the light ray and the normal direction of the light entrance surface 210 in the lens 200 and the angle between the light ray and the normal direction of the light exit surface 220 in the lens 200 , so that the angle between the light ray and the normal direction of the light entrance surface 210 in the lens 200 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220

[0084] Again according to the law of refraction, we have:

[0085] ;

[0086] ;

[0087] wherein, the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220

[0088] Then the light emitted by the light source 100 is simulated as a straight line L3 in the coordinate system, and the slope of the straight line L3 is k3, then k3 satisfies:

[0089] ;

[0090] the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220

[0091] ;

[0092] wherein, the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220 the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220

[0093] Meanwhile, the above two formulas also show the relationship between the angle between the light emitted by the light source 100 and the normal direction of the light emitting surface 220, and the surface shape of the light emitting surface 220 ;

[0094] ​It can be assumed that the light intensity emitted by the light source 100 is , the normalized spectrum of the light emitted by the light source 100 is , and the spectral integration of a point on the illumination surface 300 is:

[0095] Equation Two

[0096] wherein and represent the lower limit and the upper limit of the integral, respectively, , .

[0097] If the spectral consistency of each point on the illumination surface 300 is to be ensured, the transmittance distribution of the light filter film 500 should satisfy:

[0098] Equation One

[0099] It can be understood that if the transmittance distribution of the light filter film 500 satisfies the above equation, the spectral integration of the light rays irradiated onto any point on the illumination surface 300 through the light filter film 500 is consistent, and is the same as the spectral integration of the light rays at the optical axis of the illumination surface 300. At this time, the light rays irradiated onto the illumination surface 300 have good color uniformity. It can be understood that according to the above condition, the problem of differences in color coordinates of the light rays irradiated onto the illumination surface 300 due to different light emitting positions and angles of the light rays and different optical paths of the light rays in the lens 200 can be compensated by designing the transmittance distribution of the light filter film 500. The light rays emitted by the light source 100 can have the same spectral integration and color coordinates after passing through the lens 200 and the light filter film 500, and the phenomenon of color non-uniformity does not occur.

[0100] In some embodiments, the light filter film 500 is coated on the illumination surface 300, which facilitates the miniaturization design of the illumination system 10.

[0101] In some embodiments, the light filter film 500 includes a multilayer film structure disposed on the illumination surface 300. By designing the multilayer film structure, the light filter film 500 that can adjust the spectral integration of the light rays irradiated onto any point on the illumination surface 300 is formed.

[0102] In some embodiments, the materials or thicknesses of at least two film structures of the light filter film 500 are different, and the materials and thicknesses of at least two film structures can also be different, so as to design a suitable light filter film 500 to keep the spectral integration of the light rays irradiated onto any point on the illumination surface 300 consistent.

[0103] In some embodiments, the thickness or surface shape of the light filtering film 500 at at least two different positions can be set to be different, and the thickness and surface shape of the light filtering film 500 at at least two different positions can be set to be different, so that a suitable light filtering film 500 can be designed to keep the spectral integration of the light irradiated onto any point of the illumination surface 300 consistent.

[0104] It can be understood that the material, thickness and surface shape of the light filtering film 500 at different positions can be set to be different, and the light filtering film 500 can be set to include a multi-layer film structure, and the coverage, material and thickness of each layer of the film structure can be set to be different, so that the transmittance of the light filtering film 500 at different positions is different.

[0105] In some embodiments, the optical functional device includes a liquid crystal layer, the liquid crystal layer is arranged towards the light exit surface 220 of the lens 200, and the side of the liquid crystal layer towards the lens 200 is the illumination surface 300. It can be understood that the light emitted by the light source 100 is irradiated onto the illumination surface 300 of the liquid crystal layer through the lens 200, and then is incident into the liquid crystal layer, and the liquid crystal molecules are stimulated by the current to form a picture in cooperation with the light emitted by the light source 100. In some embodiments, the optical functional device can also be set as a collimating lens, and the side of the collimating lens towards the lens 200 is the illumination surface 300.

[0106] In some embodiments, the normalized spectrum of the light emitted by the light source 100 can also be made consistent by different designs of the light source 100. The above formula two is satisfied, and the above formula three is also satisfied. Thus, the spectrum of the light incident onto each position of the illumination surface 300 can be made consistent. The light source 100 includes a light emitting chip, and the light intensity of the light emitted by the light emitting chip is adjustable. The spectrum of the light emitted by the light source 100 at different positions can be adjusted by selecting a suitable type of light emitting chip and designing the structure of the light emitting chip, and the intensity of the light emitted by the light source 100 can be adjusted according to the actual use, so that the normalized spectrum of the light emitted by the light source 100 satisfies the above conditions, so that the spectrum of the light incident onto each position of the illumination surface 300 can be made consistent, or the spectral uniformity of the light irradiated onto each position of the illumination surface 300 is improved, and thus the color uniformity of the illumination system 10 is improved, and the display effect of the projection device is improved.

[0107] In some embodiments, the light source 100 includes a plurality of light emitting regions, and the light intensity of the light emitted by each light emitting region is independently controllable. The light intensity of different light emitting regions can be adjusted to make the spectrum of the light incident onto each position of the illumination surface 300 consistent. In some embodiments, the light source 100 is set as a light emitting diode (LED).

[0108] In some embodiments, the light-emitting area includes a plurality of light-emitting chips arranged in an array. The light-emitting chips in different light-emitting areas can be independently adjusted, and cooperated with the filter film 500 for local transmittance adjustment, so that the lighting system 10 has good imaging color uniformity for incident light at different positions. That is, through local adjustment, the chromatic aberration of light can be reduced without changing the entire filter film 500 or the light source 100.

[0109] In some embodiments, the side of the light source 100 facing the lens 200 is coated with phosphor. This phosphor coating design can be used to obtain appropriate light emitted by the light source 100 to meet the conditions for the spectral distribution at each point on the light source 100, further improving the color uniformity of the illumination system 10. In some embodiments, by setting different thicknesses or surface shapes of the phosphor at different locations on the light source 100, the spectral distribution at each point on the light source 100 satisfies Formulas 1 and 2, thereby ensuring that the spectral integral of the light irradiating any point on the illumination surface 300 is consistent. Furthermore, by setting different thicknesses and surface shapes of the phosphor at different locations on the light source 100, the spectral integral of the light irradiating any point on the illumination surface 300 is ensured to be consistent, thereby improving the color uniformity of the illumination system 10 and enhancing the display effect of the projection device.

[0110] In some embodiments, the color uniformity of the lighting system 10 can be improved by adjusting the surface shape of the lens 200. According to the above analysis, the angle between the light in the lens 200 and the normal direction of the light emitting surface 220 is known to be: The surface shape g(x) of the light exiting surface 220 of the lens 200 and the surface shape g(x) of the light incident surface 210 of the lens 200 are respectively Then the angle between the light in the lens 200 and the normal direction of the light emitting surface 220 is The relationship between the angle θ between the light incident on the illumination surface 300 and the illumination surface 300 can be used to determine the surface shape of the light incident surface 210 of the lens 200. The relationship between the angle θ between the light irradiating the lighting surface 300 and the lighting surface 300 and the relationship between the surface shape g(x) of the light emitting surface 220 of the lens 200 and the angle θ between the light irradiating the lighting surface 300 and the lighting surface 300 can be known.

[0111] It can be seen that the surface shape of the light incident surface 210 of the lens 200 is adjusted And the surface shape g(x) of the light-emitting surface 220 of the lens 200 satisfies:

[0112] ;and

[0113] hour;

[0114] After the light emitted by the light source 100 passes through the lens 200 satisfying the above conditions and irradiates on the illumination surface 300, the spectral integration of the light at each position on the illumination surface 300 remains consistent, so that the illumination system 10 has better color uniformity.

[0115] In some embodiments, the light entrance surface 210 of the lens 200 is convex, the light exit surface 220 is convex, and the lens 200 includes a lens with positive optical power, so that the lens 200 functions to converge light, so as to be able to receive the light emitted by the light source 100 and propagate and converge the light on the illumination surface 300.

[0116] In some embodiments, a plurality of lenses can also be arranged between the light source 100 and the illumination surface 300, such as Figure 2 In the middle, a Fresnel lens 400 is arranged between the lens 200 and the illumination surface 300, or it can be understood that the lens 200 can be replaced by a lens group. For the lens group form, the spectral distribution of the light emitted by the light source 100 still needs to satisfy the conditions shown in the above analysis, by setting the slope of each light and the surface equation of each surface of the plurality of lenses, and the angle relationship between each light and the light entrance surface 210 or the light exit surface 220 of the corresponding lens, it is correspondingly obtained that when the light is irradiated on the illumination surface 300 at an angle of θ, the spectral distribution of the light emitted by the light source 100 and the relationship it needs to satisfy are: Corresponding to different numbers of lenses, the spectral distribution of the light emitted by the light source 100 is different, which will not be described here.

[0117] In summary, the illumination system 10 provided by the present application is designed by designing the light intensity, spectrum and other parameters of the light emitted by the light source 100, so that the structural parameters of the light filter 500 of the illumination system 10 satisfy formula one, formula two and formula three, so that the spectrum of the light irradiated on the illumination surface 300 through the lens 200 and the light filter 500 is consistent, thereby realizing the improvement of the color uniformity of the picture imaged through the illumination system 10.

[0118] The present application also provides a projection device comprising the above-mentioned illumination system 10, and the projection device further comprises a display lens arranged on the side of the illumination surface 300 away from the lens 200, in other words, the display lens is arranged on the side of the liquid crystal layer away from the lens 200 to form an image by emitting light.

[0119] In some embodiments, the display lens can be a projection lens, including one or more lenses with optical power, for adjusting and projecting the light emitted by the illumination system 10 to improve the imaging quality of the light.

[0120] The illumination system 10 and the projection device of the present application can obtain the conditions that the transmittance of the filter film 500 needs to meet if the color uniformity of the illumination system 10 is to be improved by the spectral integration of the light at a point on the illumination surface 300 related to the diameter of the lens 200, the distance between the lens 200 and the illumination surface 300, the absorption coefficient of the medium of the lens 200, and the distance between the lens 200 and the light source 100, in combination with the transmittance of the filter film 500, so that the appropriate transmittance of the filter film 500 can be selected or set according to the conditions to improve the color uniformity of the illumination system 10, which is beneficial to improve the display effect of the projection device.

[0121] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0122] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A lighting system, characterized in that: The lighting system comprises: a light source for emitting light; a lens disposed on the light-emitting side of the light source, the lens having a light-entering surface facing the light source and a light-emitting surface opposite to the light-entering surface; an optical functional device, provided on the light-emitting side of the lens, the optical functional device having an illumination surface facing the light-emitting surface; and A filter film is provided between the optical functional device and the lens; The transmittance distribution of the filter film satisfies: ； ； ； in, is the transmittance of the filter film, is the transmittance of the filter film at the axis, , , is the intensity of light emitted by the light source, is the angle of incidence of the light on the light source, is the normalized spectrum of the light source, is the spectrum of the light source at the optical axis, λ is the wavelength of the light, D is the diameter of the lens, e is the distance between the axis of the lens and the illumination surface, α is the absorption coefficient of the medium of the lens, h is the distance between the incident position of the light on the illumination surface and the optical axis, x0 is the distance between the exit position of the light on the light exit surface and the light source in the direction parallel to the optical axis, y0 is the distance between the exit position of the light on the light exit surface and the light source in the first direction, x1 is the distance between the incident position of the light on the light entrance surface and the light source in the direction parallel to the optical axis, y1 is the distance between the incident position of the light on the light entrance surface and the light source in the first direction; the optical axis and the first direction are perpendicular to each other.

2. The lighting system according to claim 1, wherein The optical functional device includes a liquid crystal layer or a collimating lens, the side of the liquid crystal layer or the collimating lens facing the lens is the lighting surface, and the filter film is plated on the lighting surface.

3. The lighting system according to claim 1, wherein The filter film includes a multi-layer film structure arranged on the lighting surface.

4. The lighting system according to claim 3, characterized in that At least two layers of the film structure have different materials and / or thicknesses.

5. The lighting system according to claim 1, wherein The thickness and / or surface shape of at least two different locations of the filter film are different.

6. The lighting system according to claim 1, wherein The light incident surface of the lens is a convex surface, the light emitting surface is a convex surface, and the lens includes a lens with positive optical power.

7. The lighting system according to claim 1, wherein The light source comprises a light emitting chip, wherein the light intensity of the light emitted by the light emitting chip is adjustable; and / or, The light source includes a plurality of light-emitting areas, each of which includes a plurality of light-emitting chips arranged in an array. The light-emitting chips in different light-emitting areas can be adjusted independently.

8. The lighting system according to claim 1, wherein: A side of the light source facing the lens is coated with fluorescent powder, and the thickness and / or surface shape of the fluorescent powder at different positions on the light source are different.

9. The lighting system according to claim 1, wherein: Normalized spectrum of the light source satisfy: ； 。 10. A projection device, characterized in that: Comprising the lighting system according to any one of claims 1 to 9.

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