阅读说明：本技术 投影光学系统及投影设备 (Projection optical system and projection apparatus ) 是由 全丽伟 李建华 于 2020-08-24 设计创作，主要内容包括：本发明提供了一种投影光学系统。所述投影光学系统沿光线传输方向依次包括显示单元、第三镜组、第二镜组以及第一镜组,所述第一镜组具有负光焦度,所述第二镜组具有正光焦度,所述第三镜组具有正光焦度；所述投影光学系统还包括移动组件,所述移动组件分别与所述第一镜组、所述第二镜组以及所述第三镜组连接,以带动所述第一镜组、所述第二镜组以及所述第三镜组共同移动,从而使投影光学系统在变倍过程中的像面位置不移动,从在同一投射距离下无需重复对焦,画面依然清晰。本发明技术方案通过对投影光学系统的光焦度进行合理分配,减小投影光学系统的总长,并将第一镜组、第二镜组以及第三镜组联动设置,实现变倍过程中保持画面清晰的效果。(The invention provides a projection optical system. The projection optical system sequentially comprises a display unit, a third lens group, a second lens group and a first lens group along a light transmission direction, wherein the first lens group has negative focal power, the second lens group has positive focal power, and the third lens group has positive focal power; the projection optical system further comprises a moving assembly, and the moving assembly is respectively connected with the first lens group, the second lens group and the third lens group to drive the first lens group, the second lens group and the third lens group to move together, so that the image surface position of the projection optical system in the zooming process does not move, repeated focusing is not needed in the same projection distance, and the image is still clear. According to the technical scheme, the focal power of the projection optical system is reasonably distributed, the total length of the projection optical system is reduced, and the first lens group, the second lens group and the third lens group are arranged in a linkage mode, so that the effect of keeping clear pictures in the zooming process is achieved.)

1. A projection optical system is characterized by comprising a display unit, a third lens group, a second lens group and a first lens group in sequence along a light transmission direction, wherein the first lens group, the second lens group and the third lens group at least comprise one lens;

the first lens group has negative focal power, the second lens group has positive focal power, and the third lens group has positive focal power;

the projection optical system further comprises a moving assembly, and the moving assembly is respectively connected with the first lens group, the second lens group and the third lens group so as to drive the first lens group, the second lens group and the third lens group to move together.

2. The projection optical system according to claim 1, wherein the projection optical system satisfies the following relationship:

wherein the content of the first and second substances,

the above-mentioned

the above-mentioned

the above-mentionedRepresents the optical power of the third lens group, theRepresents the aboveAbsolute value of (a).

3. The projection optical system according to claim 1, wherein the lenses of the first lens group, the second lens group and the third lens group are all made of optical glass.

4. The projection optical system according to claim 2, wherein the first lens group includes a fourth lens, a third lens, a second lens, and the first lens in this order along the light transmission direction;

the second lens group sequentially comprises a seventh lens, a sixth lens and a fifth lens along the light transmission direction;

the third lens group comprises a fourteenth lens, a thirteenth lens, a twelfth lens, an eleventh lens, a tenth lens, a ninth lens and an eighth lens in sequence along the light transmission direction.

5. The projection optical system according to claim 4,

the first lens has a negative optical power; the second lens has a negative optical power;

the third lens has a negative optical power; the fourth lens has positive optical power;

the fifth lens has positive focal power; the sixth lens has a negative optical power;

the seventh lens has positive optical power; the eighth lens has a negative optical power;

the ninth lens has positive optical power; the tenth lens has a negative optical power;

the eleventh lens has a positive optical power; the twelfth lens has a negative optical power;

the thirteenth lens has a positive optical power; the fourteenth lens has positive optical power.

6. The projection optical system according to claim 4, wherein the projection optical system satisfies the following relationship:

wherein the content of the first and second substances,

the above-mentionedRepresents the power of the first lens, theRepresents the above

the above-mentionedRepresents the power of the second lens, theRepresents the aboveAbsolute value of (d);

the above-mentioned

the above-mentionedRepresents the power of the fourth lens, theRepresents the above

the above-mentioned

the above-mentioned

the above-mentioned

the above-mentioned

the above-mentioned

the above-mentionedRepresents the power of the twelfth lens cemented with the thirteenth lens

the above-mentionedRepresents the power of the fourteenth lensRepresents the aboveAbsolute value of (a).

7. The projection optical system according to claim 4, wherein the projection optical system satisfies:

75<VD₃<95, said represents VD₃Representing an abbe number of the third lens;

1.80<ND₅<1.81 said ND₅Represents a refractive index of the fifth lens;

1.0<ND₇/ND₆<1.03 said ND₇Represents a refractive index of the seventh lens, the ND₆Indicating the refractive index of the sixth lens.

8. The projection optical system according to claim 1, further comprising a turning prism disposed at an interval between the second lens group and the display unit.

9. The projection optical system according to claim 1, further comprising a diaphragm disposed between the first lens group and the second lens group.

10. A projection apparatus comprising a housing and the projection optical system according to any one of claims 1 to 9, the projection optical system being housed in the housing.

Technical Field

The invention relates to the technical field of optical imaging, in particular to a projection optical system and projection equipment.

Background

The projection equipment can project pictures with different sizes in a fixed space, and the flexibility and the convenience of the projection equipment enable the projection equipment to be used in different occasions. The display unit and the optical system are core components in the projection equipment, most of projection lenses in the current market are designed in a mode of combining and using a plurality of lens groups, the number of the lens groups is usually more than 4, when the zoom ratio of the projection equipment is larger, the number of the lens groups is usually more than 7, and the assembly and assembly difficulty of the projection equipment is seriously increased.

Disclosure of Invention

The invention mainly aims to provide a projection optical system, and aims to solve the problem that the assembly and assembly difficulty of projection equipment is high due to the fact that the number of lens groups in the optical system of the projection equipment is large.

In order to achieve the above object, the present invention provides a projection optical system, which sequentially includes a display unit, a third lens group, a second lens group and a first lens group along a light transmission direction, wherein the first lens group, the second lens group and the third lens group each include at least one lens;

the first lens group, the second lens group and the third lens group can move mutually along the light transmission direction;

the first lens group has negative focal power, the second lens group has positive focal power, and the third lens group has positive focal power;

the projection optical system further comprises a moving assembly, and the moving assembly is respectively connected with the first lens group, the second lens group and the third lens group so as to drive the first lens group, the second lens group and the third lens group to move together.

Preferably, the projection optical system satisfies the following relationship:

wherein the content of the first and second substances,

the above-mentionedRepresenting the optical power of said first set of lenses, saidRepresents the above

Absolute value of (d);

the above-mentionedRepresenting the optical power of said second set of lenses, said

Represents the above

Absolute value of (d);

the above-mentionedRepresents the optical power of the third lens group, the

Represents the above

Absolute value of (a).

Preferably, the lenses of the first lens group, the second lens group and the third lens group are all made of optical glass.

Preferably, the first lens group sequentially includes a fourth lens, a third lens, a second lens and a first lens along the light transmission direction;

the second lens group sequentially comprises a seventh lens, a sixth lens and a fifth lens along the light transmission direction;

the third lens group comprises a fourteenth lens, a thirteenth lens, a twelfth lens, an eleventh lens, a tenth lens, a ninth lens and an eighth lens in sequence along the light transmission direction.

Preferably, the first lens has a negative optical power; the second lens has a negative optical power;

the third lens has a negative optical power; the fourth lens has positive optical power;

the fifth lens has positive focal power; the sixth lens has a negative optical power;

the seventh lens has positive optical power; the eighth lens has a negative optical power;

the ninth lens has positive optical power; the tenth lens has a negative optical power;

the eleventh lens has a positive optical power; the twelfth lens has a negative optical power;

the thirteenth lens has a positive optical power; the fourteenth lens has positive optical power.

Preferably, the projection optical system satisfies the following relationship:

wherein the content of the first and second substances,

the above-mentioned

Represents the power of the first lens, the

Represents the aboveAbsolute value of (d);

the above-mentionedRepresents the power of the second lens, the

Represents the aboveAbsolute value of (d);

the above-mentioned

Represents the power of the third lens, theRepresents the above

Absolute value of (d);

the above-mentioned

Represents the power of the fourth lens, the

Represents the above

Absolute value of (d);

the above-mentioned

Represents the power of the fifth lens, theRepresents the above

Absolute value of (d);

the above-mentioned

Represents the power of the sixth lens and the seventh lens after being cemented, theRepresents the aboveAbsolute value of (d);

the above-mentioned

Represents the power of the eighth lens, the

Represents the aboveAbsolute value of (d);

the above-mentioned

Represents the power of the ninth lens, theRepresents the above

Absolute value of (d);

the above-mentioned

Represents the power of the tenth lens and the eleventh lens after they are cemented togetherRepresents the above

Absolute value of (d);

the above-mentionedRepresents the power of the twelfth lens cemented with the thirteenth lensRepresents the aboveAbsolute value of (d);

the above-mentioned

Represents the power of the fourteenth lens

Represents the aboveAbsolute value of (a).

Preferably, the projection optical system satisfies:

75<VD₃<95, said represents VD₃Representing an abbe number of the third lens;

1.80<ND₅<1.81 said ND₅Represents a refractive index of the fifth lens;

1.0<ND₇/ND₆<1.03 said ND₇Represents a refractive index of the seventh lens, the ND₆Indicating the refractive index of the sixth lens.

Preferably, the projection optical system further includes a turning prism disposed between the second mirror group and the display unit at an interval.

Preferably, the projection optical system further includes a diaphragm disposed between the first mirror group and the second mirror group.

The present application further provides a projection apparatus, which includes a housing and the projection optical system according to any one of the above embodiments, wherein the projection optical system is accommodated in the housing.

According to the technical scheme, the focal powers of the first lens group, the second lens group and the third lens group of the projection optical system are reasonably distributed, so that the number of the movable lens groups is small, and the technical problems that most projection lenses are large in size and large in group number are solved. The projection optical system according to the technical scheme of the invention comprises: the display unit, the third lens group, the second lens group and the first lens group are sequentially arranged along the light transmission direction, and light rays emitted by the display unit sequentially pass through the third lens group, the second lens group and the first lens group and then form images on an imaging surface. The projection optical system further comprises a moving assembly, wherein the moving assembly is connected with the first lens group, the second lens group and the third lens group and drives the first lens group, the second lens group and the third lens group to move together. The first lens group has negative focal power, the second lens group has positive focal power, the third lens group has positive focal power, and a linkage combination is formed among the first lens group, the second lens group and the third lens group and moves relative to the display unit together, so that the image surface position in the zooming process does not move, and therefore, under the same projection distance, focusing is not needed in the zooming process, and the image is still clear.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings 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 of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic diagram of a projection optical system according to an embodiment of the present invention;

FIG. 2 is a diagram of a modulation transfer function of an embodiment of a projection optical system according to the present invention;

FIG. 3 is a vertical axis chromatic aberration diagram of an embodiment of a projection optical system of the present invention;

FIG. 4 is a diagram of lateral chromatic aberration of an embodiment of a projection optical system of the present invention;

FIG. 5 is a diagram of field curvature distortion of a projection optical system according to an embodiment of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	First lens group	200	Second lens group
300	Third lens group	500	Display unit
				400	Steering prism	15	Diaphragm
1	First lens	2	Second lens
				3	Third lens	4	Fourth lens
5	Fifth aspect of the inventionLens and lens assembly	6	Sixth lens element
				7	Seventh lens element	8	Eighth lens element
9	Ninth lens	10	Tenth lens
				11	Eleventh lens	12	Twelfth lens element
13	Thirteenth lens	14	Fourteenth lens element

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The present invention provides a projection optical system, as shown in fig. 1, the projection optical system sequentially includes a display unit 500, a third lens group 300, a second lens group 200, and a first lens group 100 along a light transmission direction; the first lens group 100, the second lens group 200 and the third lens group 300 all comprise at least one lens; the first lens group 100, the second lens group 200 and the third lens group 300 can move along the light transmission direction; specifically, the projection optical system further includes a moving component (not shown in the figure), the moving component is connected to the first lens group 100, the second lens group 200 and the third lens group 300, and drives the first lens group 100, the second lens group 200 and the third lens group 300 to move together, wherein the first lens group 100, the second lens group 200 and the third lens group 300 are linked and move along the same direction, in an embodiment, when the first lens group 100 moves to a side close to the display unit 500, the second lens group 200 and the third lens group 300 move together to a side close to the display unit 500, in an embodiment, when the first lens group 100 moves to a side close to the display unit 500 by 0.5mm, the second lens group 200 moves to a side close to the display unit 500 by 1mm, and the third lens group 300 moves to a side close to the display unit 500 by 0.8mm, therefore, under the same projection distance, repeated focusing is not needed in the zooming process, and the picture is still clear.

It can be understood that the first lens group 100, the second lens group 200 and the third lens group 300 can be relatively independently disposed and respectively connected to the moving assembly, and when the optical system needs to be zoom-processed, the positions of the first lens group 100, the second lens group 200 and the third lens group 300 can be respectively adjusted to change the imaging effect of the projection optical system.

It is understood that the moving assembly includes an operating portion, and when the projection optical system is applied to a projection apparatus, the operating portion is disposed on a housing of the projection apparatus, and the operating portion is used for facilitating a user to adjust relative positions among the first lens group 100, the second lens group 200, and the third lens group 300.

In addition, the first lens group 100 has negative focal power, the second lens group 200 has positive focal power, and the third lens group 300 has positive focal power.

In the technical scheme of the invention, the zoom ratio is the ratio of the maximum focal length to the minimum focal length of the projection optical system in the technical scheme; the projection ratio is the ratio of the distance from the projector to the screen to the size of the projection picture; the focal power characterizes the ability of the optical system to deflect light rays, and is used

It is shown that,

the larger the value of (a), the larger the degree of deflection of the parallel beam,

when the bending is convergent,when, the flexion is divergent; abbe number is an index representing the dispersive power of a transparent medium, and the larger the refractive index of the medium is, the more severe the dispersion isThe smaller the Abbe number; conversely, the smaller the refractive index of the medium, the more slight the dispersion and the larger the abbe number; optical adhesives are special adhesives used for bonding transparent optical elements such as lenses and the like; the diaphragm is an entity which plays a role in limiting a light beam in an optical system, and the role of the diaphragm can be divided into two aspects, namely limiting the light beam or limiting a field of view, namely the size of an imaging range.

In this embodiment, the display unit 500, the third lens group 300, the second lens group 200 and the first lens group 100 are sequentially arranged along the light transmission direction, light emitted by the display unit 500 sequentially passes through the third lens group 300, the second lens group 200 and the first lens group 100 to form an image on an image plane, each of the first lens group 100, the second lens group 200 and the third lens group 300 comprises at least one lens, when the first lens group 100 comprises a plurality of lenses, the relative positions of the plurality of lenses are fixed, when the second lens group 200 comprises a plurality of lenses, the relative positions of the plurality of lenses are fixed, and when the third lens group 300 comprises a plurality of lenses, the relative positions of the plurality of lenses are fixed; the lenses in the first lens group 100, the second lens group 200 and the third lens group 300 can move integrally along the light transmission direction, which is embodied that the first lens group 100, the second lens group 200 and the third lens group 300 can be relatively close to or far away from the display unit 500; when the projection optical system of the present invention zooms from 1 time to 1.6 times, the zoom movement interval range between the respective lens groups is as follows: the interval between the first lens group 100 and the second lens group 200 is 0.66-2.72 mm, and the interval between the second lens group 200 and the third lens group is 11.39-12.00 mm. The first lens group 100, the second lens group 200 and the third lens group 300 form a linkage combination, and move together relative to the display unit 500, so that the image surface position in the zooming process does not move, and therefore, under the same projection distance, focusing is not needed in the zooming process, and the picture is still clear. According to the technical scheme, the focal powers of the third lens group 300, the second lens group 200 and the first lens group 100 of the projection optical system are reasonably matched, so that the number of movable lens groups is reduced, the total length is short, the assembly yield is improved, and batch production can be performed.

It is understood that the display unit 500 is a display chip 500, and the present invention preferably employs a Digital Micromirror Device (DMD) chip, which may be disposed offset from the optical axis by 100% -110%. It is understood that, in other embodiments, the Display unit 500 may also be a Liquid Crystal On Silicon (LCOS), an organic Light-Emitting Display (OLED), a Liquid Crystal Display (LCD), a Light-Emitting Diode (LED), or the like.

Preferably, the projection optical system satisfies the following relationship: wherein, the

Represents the optical power of the first lens group 100, the

Represents the above

Absolute value of (d); the above-mentionedRepresents the power of the second lens group 200, theRepresents the above

Absolute value of (d); the above-mentionedRepresents the power of the third lens group 300, theRepresents the aboveAbsolute value of (a).

In this embodiment, the third lens group 300 has positive focal power along the light transmission direction, i.e. satisfies the requirementThe light rays can be converged in a zigzag manner through the third lens group 300, and the second lens group 200 has a positive focal powerThe light rays can be converged in a zigzag manner through the second lens group 200, and the first lens group 100 has a negative focal power, that is, the requirement ofThe first lens group 100 can make the light rays diverge in a zigzag manner. The third lens group 300, the second lens group 200 and the first lens group 100 are arranged according to the focal power parameter, so that the zoom ratio of more than 1.6 times can be realized by using fewer groups, and meanwhile, the numerical value of the projection ratio of the optical system is less than 1.2.

Preferably, the lenses of the first lens group 100, the second lens group 200 and the third lens group 300 are all made of optical glass.

In this embodiment, each lens element of the first lens group 100, the second lens group 200 and the third lens group 300 of the projection optical system is a full glass lens element. At present, the projector lens mainly comprises two types: a glass lens and a resin lens. Because the resin material has low strength and unstable chemical characteristics, the resin material is easily influenced by temperature, so that phenomena such as coke leakage, virtual coke and the like appear on a picture; for the picture, the color reduction degree is not as good as that of a glass lens. The inverse glass lens has high hardness and wear resistance, and secondly, in the imaging effect, the general refractive index of the glass lens is higher than that of the resin lens, and the color reduction degree of the projected picture is high; in terms of chemical characteristic performance, the glass lens is more stable, cannot be burnt due to expansion caused by heat and contraction caused by cold, is more corrosion-resistant, and prolongs the service life of the lens; therefore, the full-glass lens is adopted to better avoid the phenomena of thermal deformation, virtual focus and the like caused by heating of the resin aspheric lens, and the glass lens also has the advantages of difficult deformation, good image resolution and good permeability.

Preferably, the first lens group 100 includes, in order along the light transmission direction, a fourth lens 4, a third lens 3, a second lens 2, and a first lens 1; the second lens group 200 sequentially comprises a seventh lens 7, a sixth lens 6 and a fifth lens 5 along the light transmission direction; the third lens group 300 includes a fourteenth lens 14, a thirteenth lens 13, a twelfth lens 12, an eleventh lens 11, a tenth lens 10, a ninth lens 9, and an eighth lens 8 in sequence along the light transmission direction.

In this embodiment, the projection optical system has three lens groups, namely a third lens group 300, a second lens group 200 and a first lens group 100, arranged along the light transmission path. The twelfth lens 12 is cemented with the thirteenth lens 13, the tenth lens 10 is cemented with the eleventh lens 11, and the sixth lens 6 is cemented with the seventh lens 7, wherein the twelfth lens 12 is cemented with the thirteenth lens 13, the tenth lens 10 is cemented with the eleventh lens 11, and the sixth lens 6 is cemented with the seventh lens 7 by glue.

It is understood that the glue used for bonding may be at least one of an Optical Clear Adhesive (OCA), a Liquid optical Adhesive (LOCA), a uv curable Adhesive, and a polyurethane Adhesive.