CN220105398U - Can be used to projected medicine lens system and projection arrangement - Google Patents

Abstract

The utility model relates to a projection-usable lens system and a projection device, wherein the lens system comprises a low-pass filter and a lens which are sequentially arranged along the direction of a light path, and the lens comprises a rear group, a middle group and a front group; the low-pass filter is composed of two birefringent crystals; the rear group of the lens consists of two positive lenses and a double-cemented lens; the middle group of the lens consists of a pair of positive and negative separating lenses and a diaphragm; the front group of the poloxamer lens consists of two negative lenses which are arranged continuously and two positive lenses which are arranged continuously; the low-pass filter is introduced into the lens system, so that the noise of a projection surface can be weakened, the rear group of the lens system enables light to be in smooth transition, high-order aberration is less, a positive lens is used near the diaphragm of the middle group, the relative aperture is increased, the brightness is improved, the positive lens of the front group is close to the projection surface, the volume can be effectively compressed, and finally the purposes of low noise, good imaging, high brightness and small volume are achieved.

Description

Can be used to projected medicine lens system and projection arrangement

Technical Field

The utility model relates to the technical field of projection lenses, in particular to a projection lens system and a projection device which can be used for projection.

Background

In the field of circuit board defect detection, a projection optical machine projects straight-line structural light stripes, the stripes deform on a curved surface of an object to be detected, and a camera and an algorithm restore a 3D model of the object to be detected according to the deformation degrees of the stripes with different angles.

The noise of the projection picture is mainly caused by the DMD of the display chip, the pixel unit of the DMD is a square reflecting mirror with a micron level, a gap of about 0.3 micron exists between the reflecting mirror and the reflecting mirror, and when the projection lens clearly images, the gap can be projected on the imaging surface. If a pure white picture is projected, the effect caused by the gap on the projection surface is similar to that caused by a black grid line covering the pure white picture, and the black grid line causes the broken cliff type of gray level to be reduced, so that normal structured light can be disturbed, and the effect is noise in the view of a camera. Although the algorithm may attenuate the noise by smoothing, this will reduce the accuracy of the restoration.

Because the camera coincides with the field of view of the projection lens, when the camera is perpendicular to the projected image, the projection lens needs to be placed obliquely with respect to the camera in order to avoid interference and the requirement of triangulation accuracy. For a conventional projection system, the inclination of the lens can cause the inclination of the imaging surface, the position of the projection surface can generate a non-confocal phenomenon, and the non-confocal phenomenon can cause virtual focus and blurring of a projection picture, so that the imaging quality is reduced.

The use of a samm lens can achieve clear imaging quality on an inclined projection surface by tilting the DMD display chip, but after tilting the DMD, the numerical aperture of the illumination system and the lens for receiving light is not matched, resulting in a decrease in projection brightness.

Considering the packaging volume of the actual product, the aperture of the projection lens is expected to be as small as possible, which further compresses the effective aperture of the optics to exacerbate the loss of brightness; there is a need for a low noise, good imaging, high brightness, and small volume, projection-compatible, juvenile system.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art, and provides a projection device and a projection system which can be used for projection.

The technical scheme adopted for solving the technical problems is as follows:

the utility model provides a structure can be used to projected aassessment lens system, wherein, along low pass filter and the aassessment lens that light path direction set gradually, the aassessment lens includes the back group that sets gradually along light path direction, well group and preceding group:

the low-pass filter is composed of two birefringent crystals;

the rear group of the said poloxamer lens is made up of two positive lens and a pair of cemented lens;

the middle group of the poloxamer lens consists of a pair of positive and negative separating lenses and a diaphragm;

the front group of the said lens is composed of two negative lenses and two positive lenses.

The utility model relates to a projection-usable poloxamer lens system, wherein the separation directions of the separation widths of two birefringent crystals forming the low-pass filter are the same, and the separation widths are 2:1.

The utility model discloses a projection-available poloxamer lens system, wherein two positive lenses of a rear group of the poloxamer lens are close to a low-pass filter, and a double-cemented lens of the rear group of the poloxamer lens is close to a middle group of the poloxamer lens.

The utility model relates to a projection-usable poloxamer lens system, wherein a pair of positive and negative separating lenses of a middle group of the poloxamer lens are respectively positioned at two sides of a diaphragm, and a negative separating lens is in a meniscus shape and a positive separating lens is in a biconvex shape.

The utility model relates to a projection-available poloxamer lens system, wherein two continuously arranged negative lenses of a front group of the poloxamer lens are close to a middle group of the poloxamer lens, two continuously arranged positive lenses are close to a projection surface, and at least one of the continuously arranged positive lenses is in a meniscus shape.

The utility model relates to a projection-usable poloxamer lens system, wherein the refractive index Nd of at least two positive lenses in the rear group of the poloxamer lens is less than or equal to 1.65, the Abbe number Vd of the positive lenses is more than or equal to 60, and the Abbe number Vd of the negative lenses in the double-cemented lens is less than or equal to 35;

the Abbe number Vd of the negative lens of the middle group of the poloxamer lens is less than or equal to 35;

the Abbe number Vd of at least one negative lens is more than or equal to 60, and the refractive index Nd of at least one positive lens is more than or equal to 1.80.

The utility model relates to a projection-usable lens system, wherein a rear group of the lens comprises a first spherical positive lens, a second spherical positive lens, a third spherical positive lens and a fourth spherical negative lens which are arranged along the direction of a light path, and the third spherical positive lens and the fourth spherical negative lens form a double-cemented lens; the middle group of the lens comprises a fifth spherical negative lens, a diaphragm and a sixth spherical positive lens which are arranged along the direction of the light path; the front group of the poloxamer lens comprises a seventh spherical negative lens, an eighth spherical negative lens, a ninth spherical positive lens and a tenth spherical positive lens which are arranged along the light path direction.

The utility model relates to a projection-usable poloxamer lens system, which further comprises a display chip, display chip protective glass and an equivalent prism, wherein the display chip and the display chip protective glass are obliquely arranged relative to an optical axis; along the light path direction, the display chip protective glass, the equivalent prism, the low-pass filter and the poloxamer lens are sequentially arranged.

A projection device, wherein the projection device is provided with the above-mentioned projection-usable lens system.

The utility model has the beneficial effects that: the low-pass filter is introduced into the lens system, and the DMD gap can be covered by overlapping the light beam divided into two parts in a tiny amplitude mode, so that projection plane noise is weakened. The back group of the lens has two positive lenses to share the focal power continuously, so that the light is smoothly transited, the higher-order aberration is reduced, the double-cemented lens is used for correcting the chromatic aberration, and the imaging quality is improved. And a positive lens is used near the middle group diaphragm, so that the relative aperture is increased, the light receiving angle is increased, and the brightness is improved. The front group continuously uses two positive lenses close to the projection surface to reduce the light height for the middle group, effectively compress the volume, and finally achieve the purposes of low noise, good imaging, high brightness and small volume.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the present utility model will be further described with reference to the accompanying drawings and embodiments, in which the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained by those skilled in the art without inventive effort:

FIG. 1 is a schematic diagram of a construction of a system of a projection-applicable juvenile camera of the present utility model;

fig. 2 (a), fig. 2 (b) and fig. 2 (c) are schematic structural diagrams of a rear group, a middle group and a front group of the inventive lens;

FIG. 3 is a schematic view of the light path of the present utility model;

FIG. 4 is a schematic view of an actual scenario in which light passes through the inventive lens system;

FIGS. 5 (a), 5 (b) and 5 (c) are MTF graphs imaged at 20, 0 and 60℃at a screen, respectively, at a projection distance of 93lp/mm at the display chip DMD corresponding to 4.88lp/mm of the projection surface; MTF diagram representing comprehensive analysis capability of optical system, in which horizontal axis represents spatial frequency, unit: turns per millimeter (cycles/mm). The vertical axis represents the value of the Modulation Transfer Function (MTF), the value of the MTF is used for evaluating the imaging quality of the lens, the range of the value is 0-1, the higher the MTF curve is, the straighter the imaging quality of the lens is, the stronger the reduction capability on a real image is, the better the curve superposition degree of each view field is, and the better the consistency of the image quality is.

FIG. 6 shows the spot intensity distribution of the projection plane pixels without adding a low pass filter to the projection plane;

FIG. 7 shows the pixel spot intensity distribution of the rear projection surface of a double-plate 0 DEG/0 DEG low-pass filter, wherein the separation width of the first birefringent crystal is 1/2 pixel straight-side width, and the separation width of the second birefringent crystal is 1/4 pixel straight-side width;

FIG. 8 shows the pixel spot intensity distribution of the rear projection surface of a double-plate 45 DEG/45 DEG low-pass filter, wherein the separation width of the first birefringent crystal is 1/2 pixel diagonal width, and the separation width of the second birefringent crystal is 1/4 pixel diagonal width.

Reference numerals in the drawings:

100 mer lens system, 101 display chip DMD,102 display chip DMD protection glass, 103 equivalent prism, 104 low pass filter, 110 mer lens rear group, 111 first spherical positive lens, 112 second spherical positive lens, 113 third spherical positive lens, 114 fourth spherical negative lens, 120 mer lens middle group, 121 fifth spherical negative lens, 122 diaphragm, 123 sixth spherical positive lens, 130 mer lens front group, 131 seventh spherical negative lens, 132 eighth spherical negative lens, 133 ninth spherical positive lens, 134 tenth spherical positive lens.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the following description will be made in detail with reference to the technical solutions in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by a person skilled in the art without any inventive effort, are intended to be within the scope of the present utility model, based on the embodiments of the present utility model.

The preferred embodiment of the present utility model provides a projection-applicable lens system and projection apparatus, as shown in FIG. 1, including the structures shown in FIG. 2 (a), FIG. 2 (b), FIG. 2 (c), FIG. 3, FIG. 4, FIG. 5 (a), FIG. 5 (b), FIG. 5 (c) and FIGS. 6-8, the low-pass filter and the poloxamer lens are sequentially arranged along the light path direction, and the poloxamer lens comprises a rear group, a middle group and a front group which are sequentially arranged along the light path direction;

the low-pass filter 104 is two birefringent crystals;

the rear group 110 of the lens consists of two spherical positive lenses and a double-cemented lens which are arranged continuously;

the middle group 120 of the lens consists of a spherical negative lens, a diaphragm and a spherical positive lens;

the front group 130 of the lens consists of two spherical negative lenses arranged in succession and two spherical positive lenses arranged in succession.

The low-pass filter 104 is introduced into the lens system, and the DMD gap can be covered by overlapping the beam in two to a small extent, so that the projection surface noise is weakened. The back group 110 of the lens has two positive lenses to share the focal power continuously, so that the light is smoothly transited, the higher-order aberration is reduced, the chromatic aberration is corrected by the aid of the double-cemented lens, and the imaging quality is improved. The positive lens is used near the middle group 120 diaphragm, the relative aperture is increased, the light receiving angle is increased, and the brightness is improved. The front group 130 uses two positive lenses adjacent to the projection surface continuously to reduce the light height for the middle group, effectively compress the volume, and finally achieve the purposes of low noise, good imaging, high brightness and small volume.

Preferably, the low-pass filter is two birefringent crystals, and the separation directions of the separation widths of the two birefringent crystals are the same and the separation width is 2:1;

the key and difficult points of image plane noise attenuation are as follows: and blurring imaging the gaps between pixels on the premise of keeping the definition of the projection surface. The difference in size between the pixel gap and the pixel itself is an order of magnitude, which is understood to be that the MTF of the high frequency needs to be weakened to ensure the MTF of the medium and low frequencies, in other words, a low-pass filter device can be introduced into the lens, and the birefringent crystal has just such characteristics.

The existing practice in the market is to blur the gap of the pixels by proper defocusing of the lens, and the mode is simple and easy to operate, but reduces the definition of an imaging surface and the depth of field while weakening the gap of the pixels;

the low-pass filter uses the birefringence of quartz crystal, and the imaging light beam from DMD passes through a quartz crystal thin plate with a certain thickness (the optical axis of the crystal forms an included angle of about 45 degrees with the incident surface), and the light beam containing the same target image information is divided into ordinary light and abnormal light to form a slightly staggered image. The effective areas of the micromirrors are staggered, so that the original gap grids can be covered, the gray scale of the gaps is improved, the gap grids are not obvious, and the noise is reduced. In general, a single piece of birefringent crystal may cause the pixel as a whole to move in one direction, and two pieces of birefringent crystal may cause the pixel as a whole to move in two directions. Different angle placements and different number combinations of the low-pass filters can achieve different movement effects.

In this patent, a mode is adopted in which the separation axes of two birefringent crystals are oriented in the same direction. Typically, the separation width is half of the size of the DMD pixel point, so that symmetrical pixel division can be formed, and the diffuse spots caused by the separation width are not too large. In this patent, the emphasis is on masking the pixel gap grid, so the number of gap coverage should be pursued, while the separation width is desirably as small as possible, so that the loss of MTF is minimized.

In this patent, there are two types of separation webs, one along the long and short sides of the pixel and one along the diagonal of the pixel. The unit 1 of the separation length is the side length of the pixel, the unit 1 of the separation length is the length of the diagonal line of the pixel, and the separation amplitude is 1/2 and 1/4. The total linear degree of the scattered spots after separation is increased by 50%, but the same grid coverage times as the orthogonal separation can be achieved.

Referring to fig. 6, this is an effect of the DMD pixels projecting onto the imaging surface without the addition of a low pass filter.

Referring to fig. 7, fig. 7 is an effect of adding a double birefringent crystal, in which the offset direction of the pixels is parallel to the side length direction of the pixels (labeled 0 °/0 °), the separation amplitude is 0.5/0.25 pixel width, and it can be seen that the gap grid is already significantly weakened compared to fig. 6. This way the effect of the grid in a single direction can be weakened, which is suitable for structured light stripes.

Referring to fig. 8, fig. 8 is also an effect of adding a double birefringent crystal, in which the offset direction of the pixels is parallel to the diagonal direction of the pixels (labeled 45 °/45 °), the separation amplitude is 0.5/0.25 pixel diagonal width, and it can be seen that the gap grid is significantly weakened compared to fig. 5. The grid effect in two directions can be weakened by the mode, the application range is wider, and the dispersion is more serious.

In conclusion, the low-pass filter can lead the objective of low noise of the poloxamer lens system to be achieved.

Preferably, the rear group of the poloxamer lens comprises a first spherical positive lens 111, a second spherical positive lens 112, a third spherical positive lens 113 and a fourth spherical negative lens 114 which are sequentially arranged along the light path direction, wherein the third spherical positive lens 113 and the fourth spherical negative lens 114 are bonded to form a double-cemented lens, the spherical positive lens 113 and the spherical positive lens 114 are close to the low-pass filter, and the double-cemented lens is close to the middle group. The beneficial effects are that: the first spherical positive lens 111 is located at the leftmost side of the lens group, and is close to the chip 101, and is a first spherical positive lens of a refractive system, and forms a large focal power lens group together with the second spherical positive lens 112, and the first spherical positive lens and the second spherical positive lens support the main focal power of the rear group, and ensure telecentricity and correction of aperture aberration. The first spherical positive lens 111 and the second spherical positive lens 112 share optical power, so that the lens surface is flat, the light height is smoothly transited from high to low, the incident angle of the light is small, and the generation of higher-order aberration is reduced. The doublet lens is positioned on the left side of the diaphragm 122, where the light is smooth without large angle deflection and does not need to bear large optical power, and the choice of the doublet lens material can be more prone to chromatic aberration correction, resulting in higher cost performance.

Preferably, the refractive index Nd of two spherical positive lenses of the rear group of the poloxamer lens is less than or equal to 1.65, the Abbe number Vd is more than or equal to 60, and the Abbe number Vd of a negative lens in the double-cemented lens is less than or equal to 35. The beneficial effects are that: considering that the lens is used for visible light wave band, the chromatic aberration needs to be effectively corrected to obtain better image quality. The spherical positive lenses 111 and 112 of the rear group share optical power, so that the refractive indexes of the two lenses can be slightly reduced, and materials with higher abbe numbers are selected, so that chromatic aberration introduced by the materials is reduced. The correction of the chromatic aberration of the system depends on the material itself to introduce little chromatic aberration on the one hand and on the compensation of chromatic aberration of the double cemented lens on the other hand. Bonding the third spherical positive lens 113 and the fourth spherical negative lens 114 to form a double cemented lens is the key of the color difference compensation of the lens. In terms of material selection, the Abbe number Vd of the spherical negative lens 114 of the double-cemented lens is less than or equal to 35 and meets the requirement of chromatic aberration compensation, and the material of the spherical positive lens can be properly adjusted according to the chromatic aberration amount required to be compensated.

In conclusion, the smooth transition of the rear group of rays can reduce high-order aberration, chromatic aberration compensation can obtain higher imaging quality, and the lens arrangement, material selection and lens shape can enable the lens system to achieve the aim of good imaging.

Preferably, the middle group of the lens comprises a fifth spherical negative lens 121, a diaphragm 122 and a sixth spherical positive lens 123, wherein the fifth spherical negative lens 121 is in a meniscus shape, the sixth spherical positive lens 123 is in a biconvex shape, and the fifth spherical negative lens and the sixth spherical positive lens are respectively located at two sides of the diaphragm. The beneficial effects are that: the fifth spherical negative lens 121 and the sixth spherical positive lens 123 form a pair of positive and negative focal power lenses, which have good correction effects on spherical aberration, coma aberration and astigmatism, particularly near the diaphragm 122, the light rays of each field of view have a relatively large overlapping area, and the lenses can effectively optimize the aperture aberration of all fields of view. The fifth spherical negative lens 121 is a negative lens of a meniscus shape, and has another function of matching with the negative lens of a double cemented lens, sharing the focal power thereof, reducing the incident angle of light, reducing the high-order aberration, and being beneficial to improving the imaging quality under a large relative aperture.

The fifth spherical negative lens 121 is located on the left side of the diaphragm, and can expand the light beam from the rear group so that the sixth spherical positive lens 123 on the right side of the diaphragm has a relatively large aperture. The beneficial effects are that: the relative aperture of the lens is increased, the light receiving angle of the lens is increased, and the brightness is further increased.

In conclusion, the middle group adopts a positive and negative spherical lens separation mode, and the spherical positive lens is arranged on the right side of the diaphragm, so that the incident angle of light is reduced, high-order aberration is reduced, the imaging quality under a large relative aperture is improved, the light receiving angle of the lens is increased, and the objective of high brightness of the lens system is achieved.

Preferably, the front group of the poloxamer lens comprises a seventh spherical negative lens 131, an eighth spherical negative lens 132, a ninth spherical positive lens 133 and a tenth spherical positive lens 134 which are sequentially arranged along the optical path direction. The seventh spherical negative lens 131 and the eighth spherical negative lens 132 as a whole provide a large negative power, and the ninth spherical positive lens 133 and the tenth spherical positive lens 134 provide a large positive power. The beneficial effects are that: the focal power of the four spherical lenses is mostly consumed internally, but because the beam height of the spherical positive lens is higher than that of the spherical negative lens, the beam has the largest beam caliber at the positive focal power surface and the smallest beam caliber at the negative focal power surface, so that the focal power contribution of the positive lens group to the whole lens exceeds that of the negative lens group with the same focal power, and the effect of reducing field curvature is achieved.

The front group of the Samsung lens continuously uses two spherical positive lenses 133 and 134 at the position close to the projection surface, the spherical positive lens 133 is in a meniscus shape, and the refractive index Nd is more than or equal to 1.80. The beneficial effects are that: the two spherical positive lenses are used for sharing the focal power, so that the shape and material parameters of the lenses can be properly adjusted to match the correction of aberration while the incidence angle of light rays is reduced. The meniscus shape of the spherical positive lens 133 can be matched with the emergent angle of the light beam, and the refractive index of Nd not less than 1.80 can be matched with the spherical positive lens to ensure that the lens surface is flatter while bearing large focal power, so that the aberration is further reduced.

The abbe number Vd of the front two spherical negative lenses 131 and 132 of the poloxamer lens is larger than 60. The beneficial effects are that: similar to the effect of using two spherical positive lenses in succession, the spherical negative lenses 131 and 132 used in succession herein also have the effect of making the lens surfaces flatter, further reducing aberrations. In addition, the spherical negative lenses 131 and 132 have a relatively remarkable effect of diverging light at the positions, and the chromatic aberration can be effectively reduced by adopting a high abbe number material. Better imaging quality is obtained.

In summary, the positive lens of the front group can effectively compress the volume near the projection plane, correct the curvature of field through the continuous use of the positive and negative lenses of the sphere, reduce the chromatic aberration through the material selection of the lens, reduce the higher order aberration through the surface curvature of the lens, and balance the volume and aberration correction. The purpose of small volume of the lens system of the medical device is achieved.

Preferably, the projection lens system further comprises a display chip, a display chip protection glass and an equivalent prism; along the light path direction, the display chip protective glass, the equivalent prism, the low-pass filter and the poloxamer lens are sequentially arranged.

The optical parameter values of the above design examples are shown in table 1 below.

FIG. 5 is a graph of MTF at the screen, with an MTF observation line pair of 4.88lp/mm. MTF diagram representing comprehensive analysis capability of optical system, in which horizontal axis represents spatial frequency, unit: number of turns per millimeter (cycles/mm), the vertical axis represents the value of the Modulation Transfer Function (MTF) used to evaluate the imaging quality of the lens, ranging from 0 _～ 1, the higher and straighter the MTF curve is, the better the imaging quality of the lens is, the stronger the reduction capability on a real image is, the better the curve superposition degree of each view field is, the better the consistency of the image quality is, and as can be seen from fig. 5, when the space frequency is 4.88lp/mm in the visible light wave band, the MTF of the whole view field is above 0.35, and the practical use requirement is met.

The following case is a Samsung lens system suitable for a 0.3 inch DMD with a throw ratio TR≡1.27, and the actual design parameters are referred to Table 1.

Table 1:

a projection device, wherein the projection device is provided with the above-mentioned projection-usable lens system.

It will be understood that modifications and variations will be apparent to those skilled in the art from the foregoing description, and it is intended that all such modifications and variations be included within the scope of the following claims.

Claims (9)

1. The utility model provides a can be used to projected poloxamer lens system, its characterized in that sets gradually along the light path direction low pass filter and the poloxamer lens, the poloxamer lens includes the back group, well group and the preceding group that set gradually along the light path direction:

the low-pass filter is composed of two birefringent crystals;

the rear group of the said poloxamer lens is made up of two positive lens and a pair of cemented lens;

the middle group of the poloxamer lens consists of a pair of positive and negative separating lenses and a diaphragm;

the front group of the said lens is composed of two negative lenses and two positive lenses.

2. The projection-enabled juvenile system of claim 1, wherein the separation of the two birefringent crystals constituting the low-pass filter is in the same direction and the separation is 2:1.

3. The system of claim 1, wherein two positive lenses of the rear set of the lens are adjacent to the low pass filter and a double cemented lens of the rear set of the lens is adjacent to the middle set of the lens.

4. The system of claim 1, wherein the pair of positive and negative separating lenses of the middle group of the lens are located on two sides of the diaphragm, respectively, and the negative separating lens is meniscus-shaped and the positive separating lens is biconvex.

5. The system of claim 1, wherein the front set of the lens has two serially arranged negative lenses adjacent to the middle set of the lens, two serially arranged positive lenses adjacent to the projection surface, and at least one of the serially arranged positive lenses is meniscus shaped.

6. The system of any one of claims 1-5, wherein the rear group of the lens has at least two positive lenses with refractive index Nd of 1.65 or less and abbe number Vd of 60 or more, and the negative lens abbe number Vd of the doublet lens is 35 or less;

the Abbe number Vd of the negative lens of the middle group of the poloxamer lens is less than or equal to 35;

the Abbe number Vd of at least one negative lens is more than or equal to 60, and the refractive index Nd of at least one positive lens is more than or equal to 1.80.

7. The system of any one of claims 1-5, wherein the rear group of the lens comprises a first spherical positive lens, a second spherical positive lens, a third spherical positive lens, and a fourth spherical negative lens arranged along the optical path direction, the third spherical positive lens and the fourth spherical negative lens forming a double cemented lens; the middle group of the lens comprises a fifth spherical negative lens, a diaphragm and a sixth spherical positive lens which are arranged along the direction of the light path; the front group of the poloxamer lens comprises a seventh spherical negative lens, an eighth spherical negative lens, a ninth spherical positive lens and a tenth spherical positive lens which are arranged along the light path direction.

8. The system of any one of claims 1-5, further comprising a display chip, a display chip cover glass, and an equivalent prism, the display chip and the display chip cover glass being disposed obliquely with respect to the optical axis; along the light path direction, the display chip protective glass, the equivalent prism, the low-pass filter and the poloxamer lens are sequentially arranged.

9. A projection device, wherein the projection device is provided with a projection-usable juvenile system according to any one of claims 1 to 8.