CN114384616A

CN114384616A - Rotary polygonal mirror, linear array light source scanning display system and projector

Info

Publication number: CN114384616A
Application number: CN202011126358.0A
Authority: CN
Inventors: 赵鹏; 陈孟浩; 吴超; 胡飞; 李屹
Original assignee: Appotronics Corp Ltd
Current assignee: Shenzhen Appotronics Corp Ltd
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2022-04-22
Also published as: WO2022083336A1

Abstract

The embodiment of the application provides a rotary polygonal mirror, a linear array light source scanning display system and a projector, wherein the rotary polygonal mirror is applied to the linear array light source scanning display system and used for receiving and reflecting collimated light beams emitted by a linear array light source to form a display image, the rotary polygonal mirror comprises n reflecting surfaces, n is larger than or equal to 2, each reflecting surface is parallel to a rotating shaft, the rotary polygonal mirror can rotate along the rotating shaft to enable the n reflecting surfaces to sequentially move to a light path of the collimated light beams along with the rotation of the rotary polygonal mirror so as to sequentially reflect the collimated light beams, the collimated light beams are reflected by the n reflecting surfaces to sequentially form n scanning line arrays on the display surface, and at least two scanning line arrays in the n scanning line arrays are displaced in a direction parallel to the rotating shaft on the display surface. The rotating polygonal mirror provided by the embodiment of the application can increase the display resolution of a projection picture under the condition that the number of laser light sources is limited, the display effect is improved, and the processing and manufacturing are convenient.

Description

Rotary polygonal mirror, linear array light source scanning display system and projector

Technical Field

The application relates to the technical field of laser projection, in particular to a rotary polygonal mirror, a linear array light source scanning display system and a projector.

Background

Scanning display is one of projection display technologies, and in the related art, a laser is used in the scanning display technology to generate a collimated light beam, and then the collimated light beam is projected by one or more scanning devices to generate a fast moving light spot on a screen. The laser scanning display technology can directly project light generated by a light source on a screen without a spatial light modulator, so that the projection efficiency is very high, and a picture with high brightness can be generated. In addition, because the brightness of the picture is directly controlled by the light source of the laser, the brightness of the laser can be directly weakened in the dark area, so that the problem that the brightness of a dark field of the projector leaks is avoided, and the dynamic contrast is very good.

Fig. 1 illustrates a schematic structural view of a laser scanning system based on a rotary polygon mirror in the related art, and as shown in fig. 1, the laser scanning system 100 includes a laser light source 110, a reflecting mirror 120, and a screen 130, the laser light source 110 generates a laser beam to be incident on the reflecting mirror 120, the reflecting mirror 120 rotates along a rotation axis 121, an included angle between the reflecting mirror 120 and the laser beam is changed, and the laser beam is scanned to the screen 130 to obtain a line. Each surface of the reflector 120 can scan a light beam by one stroke, and the laser light sources 110 arranged in the array along the direction of the rotation axis 121 can scan a plurality of rows of light spots and can be spliced to obtain a complete picture. The laser scanning technology based on the rotary polygonal mirror has many advantages, such as simple structure of the reflecting mirror, stable and easily controlled rotary working mode, and no energy loss and braking effect caused by acceleration and deceleration. However, in the related art, the resolution of the laser scanning technology depends on the closely spliced laser light source array, and in order to improve the display resolution, the number of the laser light sources needs to be greatly increased, which is technically difficult and costly to implement.

Disclosure of Invention

An object of the present application is to provide a rotary polygonal mirror, a linear array light source scanning display system and a projector to solve the above problems. The embodiment of the application realizes the aim through the following technical scheme.

In a first aspect, an embodiment of the present application provides a rotary polygonal mirror, which is applied to a linear array light source scanning display system, to receive and reflect a collimated light beam emitted by a linear array light source to form a display image, where the rotary polygonal mirror includes n reflection surfaces, where n is greater than or equal to 2, and each reflection surface is parallel to a rotation axis, the rotary polygonal mirror can rotate along the rotation axis to sequentially move the n reflection surfaces to an optical path of the collimated light beam along with rotation of the rotary polygonal mirror to sequentially reflect the collimated light beam, the collimated light beam is reflected by the n reflection surfaces to sequentially form n scanning line arrays on the display surface, and on the display surface, at least two scanning line arrays in the n scanning line arrays are displaced in a direction parallel to the rotation axis.

In one embodiment, at least two of the n reflecting surfaces are spaced from the rotation axis by a distance different from each other.

In one embodiment, the displacement is directly proportional to the difference in the spacing of each reflective surface from the axis of rotation, and the displacement is directly proportional to the angle of incidence of the collimated beam.

In one embodiment, the rotary polygonal mirror further includes transparent dielectric plates, the number of the transparent dielectric plates is less than or equal to n, the transparent dielectric plates are attached to the reflecting surface, and the collimated light beams enter the reflecting surface through the transparent dielectric plates and exit from the transparent dielectric plates after being reflected by the reflecting surface.

In one embodiment, the displacement is directly proportional to the angle of incidence of the collimated beam, the displacement is directly proportional to the thickness of the transparent dielectric plate, and the displacement is inversely proportional to the refractive index of the transparent dielectric plate.

In one embodiment, each reflecting surface is equally spaced from the rotating shaft, and the number of transparent dielectric sheets is less than n.

In one embodiment, the distance between each reflecting surface and the rotating shaft is equal, and the number of the transparent medium plates is equal to n; at least two transparent dielectric plates in the n transparent dielectric plates have different thicknesses, or the refractive indexes of at least two transparent dielectric plates in the n transparent dielectric plates are different from each other, or the thicknesses and the refractive indexes of at least two transparent dielectric plates in the n transparent dielectric plates are different from each other.

In one embodiment, the transparent dielectric sheet is made of glass or resin.

In one embodiment, the angle of incidence of the collimated beam with respect to the reflective surface is acute.

In a second aspect, an embodiment of the present application provides a linear array light source scanning display system, including a linear array light source, a rotary polygonal mirror, and a screen, where the linear array light source is configured to generate a collimated light beam, the screen includes a display surface, the rotary polygonal mirror includes n reflection surfaces, where n is greater than or equal to 2, and each reflection surface is parallel to a rotation axis, the rotary polygonal mirror is rotatable along the rotation axis so that the n reflection surfaces sequentially move to a light path of the collimated light beam along with rotation of the rotary polygonal mirror to sequentially reflect the collimated light beam, the collimated light beam is reflected by the n reflection surfaces to sequentially form n scanning line arrays on the display surface, and on the display surface, at least two scanning line arrays in the n scanning line arrays are displaced in a direction parallel to the rotation axis.

In a third aspect, an embodiment of the present application provides a projector including a housing and the rotary polygon mirror according to the first aspect, wherein the rotary polygon mirror is disposed in the housing.

Compared with the prior art, the rotary polygonal mirror, the linear array light source scanning display system and the projector provided by the embodiment of the application form n scanning line arrays by reflecting collimated light beams through the rotary polygonal mirror, at least two scanning line arrays in the n scanning line arrays are displaced in the direction parallel to the rotating shaft, so that at least two scanning line arrays in different positions exist in a final projection picture in the direction parallel to the rotating shaft, the display resolution of the projection picture can be increased under the condition that the number of laser light sources is limited, and the processing and manufacturing are convenient.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a laser scanning system based on a rotary polygon mirror in the related art.

Fig. 2 is a schematic structural diagram of a linear array light source scanning display system provided in an embodiment of the present application.

Fig. 3 is a schematic cross-sectional view of a rotary polygon mirror provided in an embodiment of the present application.

Fig. 4 is an optical path diagram of a rotary polygon mirror provided in the embodiment shown in fig. 3.

Fig. 5 is a schematic cross-sectional view of a rotary polygon mirror provided in another embodiment of the present application.

Fig. 6 is an optical path diagram of a rotary polygon mirror provided in the embodiment shown in fig. 5.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

At present, the resolution of a laser scanning technology based on a rotating polygonal mirror depends on a close-spliced laser light source array, and in order to improve the display resolution, the number of laser light sources needs to be greatly increased, so that the realization has technical difficulties and high cost.

In some related arts, the respective reflecting surfaces of the reflecting mirrors are set to be inclined with respect to the rotation axis, and when the laser light source is incident on the respective reflecting surfaces, the reflected light rays have different inclination angles in the direction of the rotation axis, so that the scan lines formed by the reflection of the respective reflecting surfaces are located at different line positions in the screen. However, the inclination angle of the reflecting surface has very high precision requirement on the processing technology, is often difficult to control accurately, and has high cost.

In order to solve the above-described problems, the inventors have studied and proposed a rotary polygon mirror, a line light source scanning display system, and a projector in the embodiments of the present application.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all 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 application.

Referring to fig. 2, the rotary polygon mirror 220 provided in this embodiment of the present application may be applied to a linear array light source scanning display system 200, the linear array light source scanning display system 200 may include a linear array light source 210 and a screen 250, the linear array light source 210 is configured to generate a collimated light beam 211, the screen 250 includes a display surface 251, and the rotary polygon mirror 220 is configured to receive and reflect the collimated light beam 211 emitted by the linear array light source 210 to form a display image.

The rotating polygonal mirror 220 may include n reflecting surfaces 230, where n is greater than or equal to 2, each reflecting surface 230 is parallel to the rotating shaft 240, the rotating polygonal mirror 220 may rotate along the rotating shaft 240 so that the n reflecting surfaces 230 sequentially move to the optical path of the collimated light beam 211 along with the rotation of the rotating polygonal mirror 220 to sequentially reflect the collimated light beam 211, the collimated light beam 211 is reflected by the n reflecting surfaces 230 and then sequentially forms n scanning line arrays 280 on the display surface 251, and on the display surface 251, at least two scanning line arrays of the n scanning line arrays 280 are displaced in a direction parallel to the rotating shaft 240.

For example, the n scan line arrays 280 include a first position scan line array 281 and a second position scan line array 282, and the second position scan line array 282 is displaced in the direction parallel to the rotation axis 240 relative to the first position scan line array 281, so that the final projection image has at least two scan line arrays in different positions in the direction parallel to the rotation axis 240, that is, the longitudinal resolution is increased by at least one time, thereby greatly increasing the display resolution of the projection image under the condition that the number of laser light sources is limited, and improving the display effect. In addition, the n scan line arrays 280 formed by the linear array light source scanning display system 200 can be directly transmitted to the screen without passing through a spatial light modulator, so that the projection efficiency is high, and a high-brightness projection picture can be generated.

As an example, the line light source 210 comprises m line arrays of lasers, where m is greater than or equal to 1, the m lasers generate m collimated light beams, and the m collimated light beams form m lines after being scanned by one reflecting surface, i.e. each scanning line array 280 comprises m lines. When the n scan line arrays 280 are all displaced in the direction parallel to the rotation axis 240, the final projection image has m × n lines, that is, the longitudinal resolution is m × n, and at this time, the longitudinal resolution is increased by n times compared with the case where the scan line arrays are not displaced, thereby greatly increasing the display resolution of the projection image.

It should be noted that the displacement of the scan line array 280 in a direction parallel to the rotation axis 240 is very small, such as one pixel (approximately equal to 0.35 mm). When the rotating polygon mirror 220 rotates rapidly, the persistence of vision effect of the human eye causes the human eye to observe a projection picture formed by overlapping the n scan line arrays 280 on the screen 250.

In this embodiment, the linear array light source 210 may be lasers arranged in a linear array, or may also be a linear array light source that shapes light beams generated by a plurality of lasers into one linear array light source by using optical fibers as a light beam shaping device through optical fiber coupling, which is not particularly limited in this embodiment.

In this embodiment, the reflecting surfaces 230 are flat surfaces, the number n of the reflecting surfaces 230 may be equal to or greater than 2, and when n is equal to 2, the rotary polygonal mirror 220 includes 2 reflecting surfaces 230 and further includes non-reflecting surfaces, and the non-reflecting surfaces and the 2 reflecting surfaces 230 enclose and form an outer peripheral surface of the rotary polygonal mirror 220. When n is equal to or greater than 3, the outer circumferential surface of the rotary polygonal mirror 220 may be directly surrounded by the reflection surface 220.

In this embodiment, the linear array light source scanning display system 200 further includes a cylindrical lens 260, the cylindrical lens 260 is located in the reflection optical path of the collimated light beam 211 and is located between the screen 250 and the rotating polygonal mirror 220, and the collimated light beam 211 is refracted by the cylindrical lens 260 and then enters the screen 250.

The lenticular lens 260 is disposed between the rotary polygon mirror 220 and the screen 250, and controls a traveling direction of light rays by transmission and refraction so that light beams can be incident to the screen 250 at a correct angle. The lenticular lens 260 may include an incident surface 261 and an exit surface 262 that are oppositely disposed, where the incident surface 261 is a plane, the exit surface 262 is a curved surface, and the collimated light beam 211 is incident through the incident surface 261 and then refracted at the exit surface 262. The structure of the lenticular lens 260 is not particularly limited in the embodiments of the present application, as long as the traveling direction of the light can be controlled so that the light beam can be incident on the screen 250 at a correct angle.

Fig. 3 is a schematic cross-sectional view of a rotary polygon mirror according to an embodiment of the present application, and please refer to fig. 3, in an embodiment of the present application, at least two reflecting surfaces of the n reflecting surfaces 230 have different distances from the rotation axis 240. For example, the n reflecting surfaces 230 include a first reflecting surface 231 and a second reflecting surface 232, and the first reflecting surface 231 and the second reflecting surface 232 are spaced apart from the rotating shaft 240 by different distances. Of course, the n reflecting surfaces 230 may also include other reflecting surfaces with equal or unequal distances from the rotating shaft 240.

Fig. 4 is a light path diagram of the rotary polygon mirror provided in the embodiment shown in fig. 3, and in conjunction with fig. 3 and 4, when the first reflection surface 231 rotates to the light path of the collimated light beam 211, the collimated light beam 211 is reflected by the first reflection surface 231 to form a first reflected light beam 212. When the second reflecting surface 232 rotates to the optical path of the collimated light beam 211, the collimated light beam 211 is reflected by the second reflecting surface 232 to form a second reflected light beam 213, and at this time, the second reflected light beam 213 is shifted by Δ from the first reflected light beam 212 in a direction parallel to the rotation axis 240 (see fig. 2 in detail).

Assuming that the difference between the distances between the first and second reflecting

surfaces

231 and 232 and the rotating shaft 240 is d, the calculation formula of the displacement Δ can be obtained according to the geometrical relationship as follows:

Δ＝2θd (1)

in equation (1), θ is the incident angle of the collimated light beam 211 with respect to the reflecting surface 230, i.e. the angle between the collimated light beam 211 and the normal of the reflecting surface 230. It should be noted that the incident angle θ is an acute angle, i.e., the collimated light beam 211 is neither perpendicular to the reflecting surface 230 nor parallel to the reflecting surface 230, so that the collimated light beam 211 reflected by the reflecting surface 230 can be displaced in a direction parallel to the rotating shaft 240.

As can be seen from the formula (1), the displacement Δ is in direct proportion to the incident angle θ, and the displacement Δ is in direct proportion to the difference d, so that the magnitude of the displacement Δ can be controlled by controlling the incident angle θ and the difference d. When the incident angle θ is a small angle (e.g., less than 0.01 °), a variation on the order of d mm of the difference may realize a variation on the order of Δ μm of the displacement, and the rotary polygon mirror 220 may realize a production of the difference d on the order of mm. Compared with the related art in which the reflective surfaces with different tilt angles are prepared on the rotary polygonal mirror, it is obviously easier to operate to prepare the reflective surface 230 with a different distance from the rotating shaft 240 on the rotary polygonal mirror 220, so that the preparation of the device is simpler, and meanwhile, the manufacturing error can be reduced, and the precise control of the reflected light beam can be realized. In addition, different displacements Δ may be generated by adjusting the incident angle θ, so that one rotary polygon mirror 220 is adapted to various usage scenarios.

The first and second reflecting

surfaces

231 and 232 may be two adjacent outer peripheral surfaces of the rotary polygonal mirror 220, or may be two non-adjacent outer peripheral surfaces, as long as the distances between the first and second reflecting

surfaces

231 and 232 and the rotating shaft 240 are not equal to each other.

When n is equal to or greater than 3, the distances between only two reflecting surfaces 230 and the rotating shaft may be different from each other, or the distances between each reflecting surface 230 and the rotating shaft 240 may be different from each other, and the distance between each reflecting surface 230 and the rotating shaft 240 may decrease clockwise to form a regular change, or may change irregularly, so that each scanning line array formed by scanning the rotating polygonal mirror 220 is displaced in a direction parallel to the rotating shaft 240, which may increase the display resolution of the projection image by n times, improve the display effect, and has a simple structural design and is very convenient to process and manufacture.

As an example, n is equal to 6, that is, the number of the reflection surfaces 230 is 6, the distances between the 6 reflection surfaces 230 and the rotation axis 240 are not equal to each other, and the distances between the 6 reflection surfaces 230 and the rotation axis 240 may decrease in a clockwise direction.

An embodiment of the present application provides a rotating polygon mirror 220 through at least two mutually unequal reflecting surfaces 230 with rotation axis 240 interval, can make at least two in the scanning line array that rotating polygon mirror 220 scans and forms take place the displacement in the direction of parallel rotation axis 240, thereby increase the display resolution of projection picture, promote the display effect, and structural design is simple, greatly reduced the manufacturing difficulty, can reduce manufacturing error simultaneously, realize the accurate control to rotating polygon mirror 220 reflected light beam.

Fig. 5 is a schematic cross-sectional view of a rotary polygon mirror according to another embodiment of the present disclosure, and as shown in fig. 5, in another embodiment of the present disclosure, the rotary polygon mirror 220 further includes transparent dielectric plates 270, the number of the transparent dielectric plates 270 is less than or equal to n, the transparent dielectric plates 270 are attached to the reflection surface 230, and the collimated light beams 211 enter the reflection surface 230 through the transparent dielectric plates 270 and exit from the transparent dielectric plates 270 after being reflected by the reflection surface 230.

The transparent dielectric plate 270 may be made of glass or resin, which has high light transmittance (e.g., greater than 90%). The transparent dielectric plate 270 may include a first surface 271 and a second surface 272 that are opposite to each other, where the first surface 271 and the second surface 272 are both parallel to the rotating shaft 240, the second surface 272 is attached to the reflecting surface 230, and the collimated light beam 211 enters the reflecting surface 230 through the first surface 271 and exits from the first surface 271 after being reflected by the reflecting surface 230.

As an example, the n reflecting surfaces 230 include a first reflecting surface 233 and a second reflecting surface 234, the first reflecting surface 233 is not provided with the transparent dielectric plate 270, and the second reflecting surface 234 is provided with the transparent dielectric plate 270, that is, the first reflecting surface 233 is an outer surface of the rotary polygonal mirror 220.

Fig. 6 is a light path diagram of the rotary polygon mirror provided in the embodiment shown in fig. 5, and in conjunction with fig. 5 and 6, when the first reflecting surface 233 rotates to the light path of the collimated light beam 211, the collimated light beam 211 is reflected by the first reflecting surface 231 to form the first reflected light beam 214. After the second reflecting surface 234 rotates to the optical path of the collimated light beam 211, the collimated light beam 211 is incident on the second reflecting surface 234 through the transparent dielectric plate 270, and is reflected by the second reflecting surface 234 to form a second reflected light beam 215, and due to the refraction of the transparent dielectric plate 270, the second reflected light beam 215 is displaced by Δ in a direction parallel to the rotating shaft 240 compared to the first reflected light beam 214.

Assuming that the thickness of the transparent dielectric plate 270 is d (i.e. the distance between the first surface 271 and the second surface 272 is d), and the refractive index is n, the calculation formula of the displacement Δ can be obtained according to the geometrical relationship as follows:

in equation (2), θ is the incident angle of the collimated light beam 211 relative to the reflecting surface 230. The incident angle θ is an acute angle so that the collimated light beam 211 reflected by the reflecting surface 230 can be displaced in a direction parallel to the rotation axis 240.

As can be seen from the formula (2), the displacement Δ is in direct proportion to the incident angle θ, the displacement Δ is in direct proportion to the thickness d of the transparent dielectric plate 270, and the displacement Δ is in inverse proportion to the refractive index n of the transparent dielectric plate 270, and the magnitude of the displacement Δ can be controlled by controlling one or more of the incident angle θ, the thickness d of the transparent dielectric plate, and the refractive index n of the transparent dielectric plate. When the incident angle θ is a small angle (e.g., less than 0.01 °), the displacement Δ μm can be changed by d mm-order change in thickness, and accordingly, a millimeter-order transparent dielectric plate is required. Compared with the prior art that the reflecting surfaces with different inclination angles are prepared on the rotary polygonal mirror, the operation is easier to perform when the transparent medium plates with different thicknesses or refractive indexes are arranged on the rotary polygonal mirror, the preparation process is simpler, the manufacturing error can be reduced, and the accurate control of the reflected light beam of the rotary polygonal mirror 220 is realized. In addition, displacements Δ of different magnitudes can be generated by adjusting the incident angle θ, so that one rotary polygon mirror can be adapted to various usage scenarios.

As an example, the distances between each of the reflective surfaces 230 and the rotating shaft 240 are equal, in this case, the number of the transparent dielectric plates 270 is less than n, that is, the rotating polygonal mirror 220 includes a reflective surface provided with a transparent dielectric plate and a reflective surface not provided with a transparent dielectric plate, so that at least two of the n scanning line arrays are displaced in a direction parallel to the rotating shaft 240, the thickness of the transparent dielectric plate 270 and the refractive index of the transparent dielectric plate 270 may be the same or different, and those skilled in the art may set the distances according to actual needs.

As an example, each of the reflecting surfaces 230 is equally spaced from the rotating shaft 240, and the number of the transparent dielectric sheets 270 is equal to n, that is, each of the reflecting surfaces 230 is provided with one transparent dielectric sheet 270. In this case, the thickness d of at least two transparent dielectric plates in the n transparent dielectric plates 270 is different from each other, or the refractive index n of at least two transparent dielectric plates in the n transparent dielectric plates 270 is different from each other, or the thickness d and the refractive index n of at least two transparent dielectric plates in the n transparent dielectric plates are different from each other, so that at least two scanning line arrays in the n scanning line arrays formed by scanning are displaced in a direction parallel to the rotation axis 240.

As an example, n is equal to 6, i.e. the number of the reflection surfaces 230 is 6, and the distances between the 6 reflection surfaces and the rotation axis 240 are all equal. The number of the transparent dielectric slabs 270 is 5, the 5 transparent dielectric slabs 270 are sequentially arranged on the adjacent 5 reflecting surfaces 230, the refractive indexes of the 5 transparent dielectric slabs 270 are equal, the thickness is gradually decreased along the clockwise direction, the display resolution of a projection picture can be increased by 6 times, and the transparent dielectric slabs 270 are made of the same material and can be processed and manufactured conveniently.

Of course, in some other embodiments, the n reflecting surfaces 230 may have unequal distances from the rotating shaft 240, and the n reflecting surfaces 230 are attached with one or more transparent dielectric plates 270, in which case, the displacement of the scanning line array in the direction parallel to the rotating shaft 240 may be controlled by controlling one or more of the distances between the reflecting surfaces 230 and the rotating shaft 240, the incident angle of the collimated light beam 211, and the thickness and the refractive index of the transparent dielectric plate 270, which are all feasible, and can be designed by those skilled in the art according to actual needs.

Another embodiment of the application provides a rotating polygon mirror 220 includes rotating polygon mirror 220 and transparent dielectric slab 270, transparent dielectric slab 270 laminates in at least one plane of reflection 230, refraction effect through transparent dielectric slab 270, can make at least two in the n scanning line array that rotating polygon mirror 220 scans and forms take place the displacement in the direction of parallel rotation axle 240, increase the display resolution on projection picture, promote display effect, and structural design is simple, greatly reduced the processing and manufacturing degree of difficulty, can reduce manufacturing error simultaneously, realize the accurate control to rotating polygon mirror 220 reflected light beam.

Still referring to fig. 2, an embodiment of the present application further provides a linear array light source scanning display system 200, which includes a linear array light source 210, a rotating polygon mirror 220, and a screen 250.

The linear array light source 210 is configured to generate a collimated light beam 211, the screen 250 includes a display surface 251, the rotary polygon mirror 220 may include n reflecting surfaces 230, where n is greater than or equal to 2, and each reflecting surface 230 is parallel to the rotation axis 240, the rotary polygon mirror 220 may rotate along the rotation axis 240 so that the n reflecting surfaces 230 sequentially move to an optical path of the collimated light beam 211 along with the rotation of the rotary polygon mirror 220 to sequentially reflect the collimated light beam 211, the collimated light beam 211 is reflected by the n reflecting surfaces 230 to sequentially form n scanning line arrays 280 on the display surface 251, and on the display surface line array 251, at least two scanning line arrays in the n scanning line arrays 280 are displaced in a direction parallel to the rotation axis 240.

The linear array light source scanning display system 200 provided in the embodiment of the present application reflects the collimated light beam by the rotating polygon mirror 220 to form n scanning line arrays 280, and at least two scanning line arrays in the n scanning line arrays 280 are displaced in the direction parallel to the rotating shaft 240, so that at least two scanning line arrays in different positions exist in the final projection picture in the direction parallel to the rotating shaft 240, the display resolution of the projection picture can be increased under the condition that the number of the laser light sources is limited, and the processing and manufacturing are convenient.

Still referring to fig. 2, an embodiment of the present application further provides a projector, which includes a housing (not shown) and a rotating polygon mirror 220, wherein the rotating polygon mirror 220 is disposed in the housing.

The projector provided by the embodiment of the application reflects the collimated light beams through the rotating polygonal mirror 220 to form n scanning line arrays 280, at least two scanning line arrays in the n scanning line arrays 280 are displaced in the direction parallel to the rotating shaft 240, so that the final projection picture at least has two scanning line arrays in different positions in the direction parallel to the rotating shaft 240, the display resolution of the projection picture can be increased under the condition that the number of laser light sources is limited, and the processing and manufacturing are convenient.

The projector may further include a line light source 210, and the line light source 210 is used for generating a collimated light beam 211. For detailed structural features of the rotary polygon mirror 220, reference is made to the description of the above-described embodiments. Since the projector includes the rotary polygon mirror 220 in the above-described embodiment, all the advantageous effects of the rotary polygon mirror 220 are provided, and the description thereof is omitted. The structural features of the other parts of the projector are within the understanding of those skilled in the art and will not be described in detail herein.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A rotary polygonal mirror for use in a linear array light source scanning display system to receive and reflect a collimated light beam from a linear array light source to form a display image,

the rotary polygonal mirror comprises n reflecting surfaces, wherein n is larger than or equal to 2, each reflecting surface is parallel to the rotating shaft, the rotary polygonal mirror can rotate along the rotating shaft, the n reflecting surfaces sequentially move to the light path of the collimated light beam along with the rotation of the rotary polygonal mirror to sequentially reflect the collimated light beam, the collimated light beam is reflected by the n reflecting surfaces and then sequentially forms n scanning line arrays on the display surface, and at least two scanning line arrays in the n scanning line arrays are displaced in the direction parallel to the rotating shaft on the display surface.

2. The rotary polygon mirror according to claim 1, wherein at least two of said n reflecting surfaces are spaced from said rotational axis by a distance different from each other.

3. The rotary polygon mirror according to claim 2, wherein the displacement is in direct proportion to a difference in a pitch of each of the reflecting surfaces and the rotating shaft, and the displacement is in direct proportion to an incident angle of the collimated light beam.

4. The rotary polygonal mirror according to claim 1, further comprising transparent dielectric plates, wherein the number of the transparent dielectric plates is less than or equal to n, the transparent dielectric plates are attached to the reflecting surface, and the collimated light beams enter the reflecting surface through the transparent dielectric plates and exit from the transparent dielectric plates after being reflected by the reflecting surface.

5. The rotary polygon mirror according to claim 4, wherein the displacement is in direct proportion to an incident angle of the collimated light beam, the displacement is in direct proportion to a thickness of the transparent dielectric plate, and the displacement is in inverse proportion to a refractive index of the transparent dielectric plate.

6. The rotary polygon mirror according to claim 4, wherein each of the reflecting surfaces is equally spaced from the rotation axis, and the number of the transparent dielectric plates is smaller than n.

7. The rotary polygon mirror according to claim 4, wherein each of the reflecting surfaces is equally spaced from the rotary shaft, and the number of the transparent dielectric plates is equal to n; the thickness of at least two transparent dielectric plates in the n transparent dielectric plates is not equal to each other, or the refractive index of at least two transparent dielectric plates in the n transparent dielectric plates is not equal to each other, or the thickness and the refractive index of at least two transparent dielectric plates in the n transparent dielectric plates are not equal to each other.

8. The rotary polygonal mirror according to claim 4, wherein the transparent dielectric plate is made of glass or resin.

9. A scanning display system for a linear array light source, comprising:

the linear array light source is used for generating collimated light beams;

the screen comprises a display surface, the rotary polygonal mirror comprises n reflecting surfaces, n is larger than or equal to 2, each reflecting surface is parallel to the rotating shaft, the rotary polygonal mirror can rotate along the rotating shaft, the n reflecting surfaces sequentially move to the light path of the collimated light beam along with the rotation of the rotary polygonal mirror so as to sequentially reflect the collimated light beam, the collimated light beam is reflected by the n reflecting surfaces and then sequentially forms n scanning line arrays on the display surface, and at least two scanning line arrays in the n scanning line arrays on the display surface are displaced in the direction parallel to the rotating shaft.

10. A projector comprising a housing and a rotary polygon mirror as recited in any one of claims 1 to 8, the rotary polygon mirror being provided to the housing.