CN213399179U - Conjugated efficient illumination system of LCD projector - Google Patents

Abstract

The utility model discloses a conjugate high-efficiency lighting system of an LCD projector, which comprises an LED light source, a square cone condenser, a collimating lens, a quarter wave plate, a brightening polarizing plate, an LCD light valve, a field lens and a projection lens which are arranged in sequence according to the advancing direction of light; the LCD projector conjugate high-efficiency illumination system also comprises a reflector arranged on an incident port of the square conical condenser; the light-passing surface of the incident port of the square conical condenser is divided equally along a horizontal central line or a vertical central line to form two sub light-passing surfaces; the light emitting surface of the LED light source is located at one of the light transmitting sub-surfaces, the reflector is located at the other light transmitting sub-surface, and the LED light source and the reflector are optically conjugated along the brightening polarizing plate. The utility model discloses really realized that projector lighting efficiency is showing and is promoting by a wide margin, compare the same luminance of prior art output, the utility model discloses can practice thrift the power consumption by a wide margin, to aspects such as reduction projector volume, noise, heat dissipation, all have positive help.

Description

Conjugated efficient illumination system of LCD projector

Technical Field

The utility model relates to a projector field especially relates to a conjugated high-efficient lighting system of LCD projector.

Background

Conventionally, a transmission-type single LCD projector is built on the condition that linearly polarized light irradiates liquid crystal molecules of the projector, a bright and dark image is generated by polarization detection, and illumination light from a light source can be almost considered as natural light, so that in the process from the natural light to the linearly polarized light, about more than or equal to 50% of the light is filtered by a polarizer of an LCD light valve, and the total polarization efficiency of the polarizer is usually less than or equal to 38% -45% in consideration of the requirement of the LCD light valve on the extinction ratio of the polarizer. Only with the illumination loss, the single LCD projector always has 55% -62% of energy to do useless work, which fundamentally influences the efficiency of the optical system of the single LCD projector and fundamentally increases the heat dissipation burden of the optical system of the projector, thereby fundamentally limiting the performance and application of the single LCD projector.

In recent years, in the domestic industry, PCS (polarized light Conversion System) patent technology with relatively low cost is continuously developed to expect improvement of optical System efficiency. The utility model discloses on this company prior art's basis (see publication No. CN111367140A, CN111399326A), kept the characteristic that the efficiency is exact, further promoted easily preparation, the good and cheap characteristic, had wider productization meaning.

SUMMERY OF THE UTILITY MODEL

In order to solve the above technical problem, an object of the present invention is to provide a conjugated high-efficiency illumination system for LCD projector, which is very easy to manufacture and cheap.

In order to achieve the above object, the present invention provides a conjugated high-efficiency illumination system for LCD projector, which comprises an LED light source, a square cone-shaped condenser, a collimating lens, a quarter-wave plate, a brightness-enhanced polarizing plate, an LCD light valve, a field lens and a projection lens, all of which are arranged in sequence according to the light traveling direction; the LCD projector conjugate high-efficiency illumination system also comprises a reflector arranged on an incident port of the square conical condenser; the light-passing surface of the incident port of the square conical condenser is divided equally along a horizontal central line or a vertical central line to form two sub light-passing surfaces; the light emitting surface of the LED light source is located at one of the light transmitting sub-surfaces, the reflector is located at the other light transmitting sub-surface, and the light emitting surface of the LED light source and the reflector are optically conjugated along the brightening polarizing plate.

Preferably, the reflector is manufactured on the LED light source, and the light emitting surface of the LED light source and the reflector are symmetrically arranged along a horizontal central line or a vertical central line of a light passing surface of the incident port of the square conical condenser;

or the reflector is manufactured at a sub light-passing surface of the incident port of the square conical condenser.

Furthermore, the brightness enhancement type polarizing plate adopts a linear polarizer, the transmission axis of the brightness enhancement type polarizing plate is consistent with the polarization plane of the incident polarized light required by the LCD, and the brightness enhancement type polarizing plate transmits the linearly polarized light required by the LCD light valve; the reflection axis and the transmission axis of the brightness enhancement type polarizing plate are orthogonal, and the brightness enhancement type polarizing plate reflects linearly polarized light orthogonal to the polarization plane of the transmission axis of the brightness enhancement type polarizing plate.

Preferably, the fast axis of the quarter-wave plate and the transmission axis of the brightness enhancing polarizer are at any one of +45 °, -45 °, +135 °, and-135 °, the polarization conversion process will achieve the highest efficiency.

Furthermore, the square cone-shaped condenser is a solid square cone-shaped light guide rod or a hollow square cone-shaped light guide rod, or a combination of the solid square cone-shaped light guide rod and the hollow square cone-shaped light guide rod.

Furthermore, the incident surface of the collimating lens is attached to the emergent end surface of the square conical condenser.

Optionally, the collimating lens is any one of a fresnel lens, a plano-convex lens, a meniscus lens, or a combination of any several kinds of lenses.

Optionally, the quarter-wave plate is formed by combining two eighth-wave plates.

Preferably, the effective fast axis of the two eighth-wave plates combined together and the transmission axis of the brightness enhancement polarizer are at any one of +45 °, -45 °, +135 ° and-135 °, and the polarization conversion process will achieve the highest efficiency.

The utility model also provides a LCD projector conjugation high efficiency lighting system's projection method, including following step:

the light emitted by the LED light source sequentially passes through the square conical condenser and the collimating lens to be collimated and then passes through the quarter-wave plate to reach the brightening polarizing plate, the brightening polarizing plate performs polarized light separation on the light, one path of polarized light which is useful for the LCD light valve is transmitted, one path of polarized light which is useless for the LCD light valve is reflected, the two paths of polarized light are linearly polarized light, the amplitude is equal, and the vibration planes are orthogonal; one path of polarized light which is useful for the LCD light valve passes through the LCD light valve and then is projected out after sequentially passing through a field lens and a projection lens; one path of polarization light which is useless for the LCD light valve is reflected back by the brightening type polarizing plate, the reflected light passes through the quarter-wave plate, is focused by the collimating lens and is collected by the square conical condenser, is focused and irradiated on the reflecting mirror, is reflected by the reflecting mirror, is collected by the square conical condenser and is collimated by the collimating lens, then passes through the quarter-wave plate to reach the brightening type polarizing plate, the reflected light passes through the quarter-wave plate twice, and then the polarization plane rotates by 90 degrees to be consistent with the transmission axis of the brightening type polarizing plate, so that one path of polarization light which is useless for the LCD light valve is available, the polarization light conversion process is completed, and the illumination efficiency of the projector is remarkably improved.

The utility model has the advantages that:

1. the utility model discloses divide the logical plain noodles of square cone spotlight ware incident end equally along horizontal center line or vertical center line, form two son and lead to the plain noodles, install LED light source and speculum respectively on two son lead to the plain noodles for LED light source and speculum are along blast type polarizing plate optics conjugation. When the natural light passing through the collimating lens is subjected to polarized light separation by the brightness-enhancing type polarizing plate, two paths of useful and useless linearly polarized light for the LCD light valve are separated, and the useless linearly polarized light is reflected back and mostly focused on the reflecting mirror and enters the square conical condenser again. Because LED light source and speculum are all in the incident port of square toper spotlight ware and optics conjugation, so behind the transmission of square toper spotlight ware, the light exhibition (optical expansion volume) can not produce obvious overflow, this way of linearly polarized light useless simultaneously, the plane of polarization is rotatory 90 after passing quarter wave plate twice in succession, makes this way of linearly polarized light useless to the LCD light valve become usable, so really realized that projector lighting efficiency is showing and is promoting by a wide margin, compare the same luminance of prior art output, the utility model discloses can practice thrift the power consumption by a wide margin, to the square face that reduces preparation such as projector volume, noise, heat dissipation, cost and user experience, all have positive help.

2. The utility model discloses with the integrated preparation of speculum in on the LED light source, or with the integrated preparation of speculum on the incident port of square cone spotlight ware, make the utility model discloses really realized when PCS technique application process, installation and preparation all become very simple, to promoting production efficiency, reduce product cost and have very positive meaning.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is an enlarged view taken at A in FIG. 1;

FIG. 3 is a partial schematic view of a light ray trace according to an embodiment of the present invention;

FIG. 4 is a graph showing an illumination profile on an LCD light valve according to an embodiment of the present invention;

fig. 5 shows illumination data on an LCD light valve according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of the prior art.

Detailed Description

In order to make the technical solution of the present invention better understood, the present invention is described in detail below with reference to the accompanying drawings, and the description of the present invention is only exemplary and explanatory, and should not be construed as limiting the scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

It should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like refer to the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that the utility model is usually placed when in use, and are used for convenience of description and simplification of description, but do not refer to or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The specific embodiment is as follows:

as shown in fig. 1 to 5, the LCD projector conjugate high-efficiency illumination system provided in this embodiment includes an LED light source 1, a square cone condenser 2, a collimating lens 3, a quarter-wave plate 4, a brightness enhancement type polarizing plate 5, an LCD light valve 6, a field lens 7, and a projection lens 8, which are sequentially arranged in the light traveling direction, and further includes a reflector 9 disposed at the incident port of the square cone condenser 2.

In this embodiment, the square-cone-shaped condenser 2 is a hollow square-cone-shaped light guide rod; the two sub-light-passing surfaces of the incident port of the square conical condenser 2 are formed by being divided equally along the vertical center line of the incident port; the light emitting surface of the LED light source 1 is located at one of the light transmitting sub-surfaces, the reflector 9 is located at the other light transmitting sub-surface, and the LED light source 1 and the reflector 9 are optically conjugated along the brightness enhancement type polarizing plate 5.

According to the principle of cosine light-emitting distribution (lambertian body light-emitting) of the LED light source 1 and the square cone condenser 2, most of main energy light rays emitted by the LED light source 1 directly reach the collimating lens 3 without being reflected by the inner wall of the hollow square cone light guide rod, and pass through the quarter-wave plate 4 after being collimated to reach the brightness-enhancing type polarizing plate 5.

The brightness enhancement type polarizing plate 5 can be equivalent to a flat spectroscope, and realizes light splitting of natural light (equivalent to two linearly polarized lights with equal amplitude and orthogonal vibration planes), namely, the transmission and reflection of the two polarized lights are realized, and the light splitting effect is generated.

Because the LED light source 1 is located on one side of the optical axis of the system, unless the light is incident on the brightness enhancement type polarizing plate 5 in parallel to the optical axis, when the brightness enhancement type polarizing plate 5 splits light, according to the basic principle of reflection, the reflected light is mirrored in the horizontal direction (i.e. the plane defined by the "vertical center line" and the "optical axis" of the incident port of the square cone condenser 2), and after being focused by the collimating lens 3, the aberration and distortion of the collimating lens 3 are subtracted, so that most of the reflected light separated by the brightness enhancement type polarizing plate 5 will inevitably fall on the reflecting mirror 9, and at this time, the image on the reflecting mirror 9 is the image of the LED light source, so that the reflecting mirror 9 and the LED light source 1 are optically conjugated along the brightness enhancement type polarizing plate 5.

The non-main energy light rays of the LED light source 1 are reflected by the brightening type polarizing plate 5 and can not reach the reflector 9, so that the non-main energy light rays are basically useless light rays; depending on the quality of the design and manufacture of the square-cone condenser 2 and the collimator lens 3, normally a large part of the reflected light rays can be returned to the reflector 9, because the aberrations, distortions and distortions of the collimator lens 3 are controllable to some extent, and the non-dominant energy rays of the certain exit angles are not dominant at all for the effect of the PCS process.

Whether software simulation or actual product testing, most of the light reflected by the brightness enhancement polarizer 5 reaches the mirror 9 and is used as effective light by the system, and the positive effects of the present embodiment will be further described below.

Referring to fig. 1, in the present embodiment, when performing professional software simulation, a "surface receiver" is placed on the incident surface of the LCD light valve 6, and an "angular luminance meter" is placed on the "surface receiver"; the luminous flux of the LED light source 1 is 10000 Lm; the square cone condenser 2 selects a hollow square cone light guide rod, two sub light passing surfaces of an incident port are formed by bisecting along a vertical central line, the size of the incident port is set to be 18.36x10.56mm, then the size of the sub light passing surfaces is 9.18x10.56mm, the size of an emergent port is 107.6x63.6mm, the length along an optical axis is 140mm, and the reflectivity of an inner wall is 100%; the collimating lens 3 is a plano-convex lens, the center is 32 thick, the material is QK2 (China), and the spherical radius of the convex surface is 82.65; the quarter-wave plate 4 and the brightening type polarizing plate 5 are integrated on a piece of glass with the thickness of 0.5, the glass material K9 (China) is adopted, the incident surface of the glass is set to be the quarter-wave plate 4 (set to be an ideal linear retarder), the emergent surface is set to be the brightening type polarizing plate 5 (set to be an ideal linear polarization light splitter), and the position of the incident surface of the glass is 0.1mm away from the top point of the emergent surface of the collimating lens 3; the LCD light valve 6 is a 4.5 inch light valve with a window size of 101 x 56.8mm, 11mm from the apex of the exit face of the collimating lens 3; the mirror 9 was sized 9.18x10.56mm with a reflectivity of 100%. The success of this embodiment is shown in table 1 below:

table 1 effect demonstration of the present embodiment

In table 1, the a-c rows show different prior art, and it is known that the increase of the illumination efficiency of the projector in the c row compared to the b row is only about 1.2% (5302.1/5239.9 is 1.2%), which is almost negligible.

Row d of table 1 illustrates the size of the light emitting face of LED light source 1, with very limited impact on the prior art, only about 0.3% compared to rows d and c.

In table 1, the linear polarization reaching the incident surface of the LCD light valve 6 reaches 7621.9Lm, and the optical efficiency of the projector is improved by not less than 140% (7621.9Lm/5302.1Lm 144%) compared with the technology of the present embodiment. In practice, the LCD light valve 6 has a transmittance of about 13% for polarized light, and the projector outputs a light flux of about 720Lm, whereas in the conventional technology of line c, the projector outputs a light flux of only 500 Lm.

Therefore, the embodiment really realizes that the illumination efficiency of the projector is remarkably and greatly improved, and the projector outputs the same brightness compared with the prior art, can greatly save the power consumption, and has positive help on the aspects of manufacturing and user experience such as reduction of the volume, noise, heat dissipation, cost and the like of the projector.

In table 1, if the incident port of the square pyramid condenser 2 is divided according to the horizontal center line, and the LED light source 1 and the reflector 9 are respectively installed on one sub light-transmitting surface, the luminous flux obtained by the surface receiver on the incident surface of the LCD light valve 6 is 7645.3Lm (linearly polarized light), but in the practical product, the LED light source 1 is arranged in a long strip shape (the length-width ratio is about 3.5: 1), and the division of the square pyramid condenser 2 along the vertical center line can obtain more freedom of the layout of the LED chip than the division along the horizontal center line in terms of efficiently designing the light source area allowed by the optical spread.

Fig. 3 is a partial screenshot of the LED light source 1 and the reflector 9 showing optical conjugation and performing light tracing (the square conical condenser 2 is hidden in the drawing), the LED light source 1 and the reflector 9 are symmetrically arranged according to the vertical center line of the light passing surface at the incident end of the square conical condenser 2, and through analyzing various solid angles of the light source one by one, most of the light reflected by the brightness enhancement type polarizing plate 5 is focused on the reflector 9, so as to be utilized by the system.

FIG. 4 shows the distribution of the surface receptor illuminance at the entrance face of the LCD light valve 6 of this embodiment (about 4.4-4.5 inches), with very good uniformity and very well-limited aperture angle.

FIG. 5 is several exemplary illumination data for a surface receiver on the entrance face of the LCD light valve 6 that can be used to quantify the uniformity of the projected image for the illumination profile of FIG. 4. In general, the serious optical design and fabrication, the goodness of fit of actual results and design is extremely high.

Referring to fig. 6, in the light traveling direction, i.e. the direction of the optical axis ZL ', an LED light source 1', a hollow square-cone-shaped condenser 2 ', a collimating lens 3', a light splitting and phase plate 45 ', and an LCD light valve 6' are sequentially disposed; the incident surface of the beam splitting and phase plate 45' is a quarter-wave plate, the emergent surface is a brightness enhancement type polarizer, and the angle between the fast axis of the quarter-wave plate and the transmission axis of the brightness enhancement type polarizer is 45 degrees.

In fig. 6, the light emitting surface of the LED light source 1' is set to 18.36 × 10.56mm, light flux 10000 Lm; the size of an incident port of the hollow square cone condenser 2 'is 18.36x10.56mm, the size of an emergent port of the hollow square cone condenser is 107.6x63.6mm, the length of the hollow square cone condenser along the direction of an optical axis ZL' is 140mm, and the reflectivity of the inner wall of the hollow square cone condenser is 100%; the collimating lens 3 'is a piece of phenanthrene mirror with the thickness of 2mm and the focal length of 142mm, the material is PMMA, the tooth depth and the annular distance are both 0.3mm, the tooth form is a standard tooth, and the tooth surface faces the LCD light valve 6'; the light emitting surface of the LED light source 1 'is attached to the incident port of the hollow square conical condenser 2' and the incident surface of the collimating lens 3 'is attached to the emergent port of the hollow square conical condenser 2'; the thickness of the light splitting and phase plate 45 'is 0.5mm, the material is K9, and the distance from the incident surface to the emergent surface of the collimating lens 3' is 4 mm; the LCD light valve 6 'is a 4.5 inch light valve with a window size 101 x 56.8mm, 11mm from the exit face of the collimating lens 3'.

In fig. 6, the actual effect of these prior art techniques is shown in table 2 below, where a "surface receptor" is placed on the entrance face of the LCD light valve 6' and an "angular luminance meter" is placed on the "surface receptor" during the optical simulation:

TABLE 2 actual Effect of the prior art

In table 2, by setting the angles of the dichroic and phase plates 45 'under the conditions of (c) -v, it can be seen that a small increase in the light irradiated on the incident surface of the LCD light valve 6' can be obtained.

If the Fno of the projector lens is 2.9 and matches the illumination shown in fig. 6, then:

in the condition of number (r) in table 2, linearly polarized light 4705.3Lm is irradiated on the LCD light valve 6', and the projector outputs a light transmission amount of about 442 Lm.

According to the condition of no, the Fno of the original light 4705.3Lm (no), is not actually affected, and the light 4766.5-4705.3 that is newly added to 61.2Lm cannot be used by the lens of Fno2.9 at all, and has no effect on the output luminous flux of the projector, so the output luminous flux of the projector is still about 442Lm, that is, the technique of the condition of no effect.

If the Fno of the projector lens is 2.4 and matches the illumination shown in fig. 6, then:

the serial number in table 2 is that the quantity of light which can be output is about 448Lm by the condition theoretical calculation; considering the use of the off-axis light by Fno2.4, the condition of sequence number (r) itself can output the transmitted light of about 515Lm, and the condition of sequence number (r) can output the transmitted light of about 520Lm because the redundant light of 61.2Lm is available, and the transmitted light of 520/515Lm is 1%, so even if the lens Fno is not increased by 2.4, the increased brightness can be almost ignored.

While the difference between the lens of Fno2.4 and 2.9, whether cost, image quality, diameter, weight, assembly accuracy requirement, etc., is very large, the smaller the Fno of the lens, the more difficult it is to make.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The principles and embodiments of the present invention have been explained herein using specific examples, which are presented only to assist in understanding the methods and their core concepts. It should be noted that there are infinite specific structures due to the limited character expressions, and it will be apparent to those skilled in the art that various improvements, decorations or changes can be made without departing from the principles of the present invention, and the technical features can be combined in a suitable manner; the application of these modifications, variations or combinations, or the application of the concepts and solutions of the present invention in other contexts without modification, is not intended to be considered as a limitation of the present invention.

Claims (7)

1. A LCD projector conjugate high-efficiency lighting system comprises an LED light source (1), a square conical condenser (2), a collimating lens (3), a quarter-wave plate (4), a brightness enhancement type polarizing plate (5), an LCD light valve (6), a field lens (7) and a projection lens (8) which are sequentially arranged according to the light advancing direction; the LCD projector conjugate high-efficiency illumination system is characterized by also comprising a reflector (9) arranged on an incident port of the square conical condenser (2); the light-passing surface of the incident port of the square conical condenser (2) is equally divided along a horizontal central line or a vertical central line to form two sub light-passing surfaces, the light-emitting surface of the LED light source (1) is positioned at one of the sub light-passing surfaces, the reflector (9) is positioned at the other sub light-passing surface, and the light-emitting surface of the LED light source (1) and the reflector (9) are positioned along the optical conjugation of the brightening polarizing plate (5).

2. The conjugate high-efficiency illumination system for LCD projector as claimed in claim 1, wherein said reflector (9) is fabricated on said LED light source (1), and the light emitting surface of said LED light source (1) and said reflector (9) are symmetrically arranged along the horizontal center line or the vertical center line of the light passing surface of the incident port of said square-cone-shaped condenser (2);

or the reflector (9) is manufactured at one sub light-passing surface of the incident port of the square conical condenser (2).

3. The conjugated high-efficiency illumination system of the LCD projector as claimed in claim 1, wherein the brightness-enhanced polarizer (5) is a linear polarizer, the transmission axis of the brightness-enhanced polarizer (5) is consistent with the polarization plane of the incident polarized light required by the LCD light valve (6), and the linearly polarized light required by the LCD light valve (6) is transmitted by the brightness-enhanced polarizer (5); the reflection axis and the transmission axis of the brightness enhancement type polarizing plate (5) are orthogonal, and the brightness enhancement type polarizing plate (5) reflects linearly polarized light orthogonal to the polarization plane of the transmission axis thereof.

4. The conjugated high-efficiency illumination system for LCD projectors of claim 1, wherein the fast axis of the quarter-wave plate (4) and the transmission axis of the brightness-enhancing polarizer (5) are at any one of +45 °, -45 °, +135 °, and-135 °.

5. The conjugated high-efficiency illumination system of the LCD projector as claimed in claim 1, wherein the square-cone-shaped condenser (2) is a solid square-cone-shaped light guide rod or a hollow square-cone-shaped light guide rod, or a combination of the solid square-cone-shaped light guide rod and the hollow square-cone-shaped light guide rod.

6. The conjugated high-efficiency illumination system of the LCD projector as claimed in claim 1, wherein the incident surface of the collimating lens (3) is attached to the exit end surface of the square cone-shaped condenser (2); the collimating lens (3) adopts any one or combination of any several of Fresnel lens, plano-convex lens and concave-convex lens.

7. The conjugated high-efficiency illumination system of the LCD projector as claimed in claim 1, wherein the quarter-wave plate (4) is formed by combining two eighth-wave plates, and the combined equivalent fast axis of the two eighth-wave plates and the transmission axis of the brightness-enhanced polarizer (5) form any one of +45 °, -45 °, +135 ° and-135 °.

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