CN110850668B

CN110850668B - Projection apparatus and pattern projection method

Info

Publication number: CN110850668B
Application number: CN201910972154.XA
Authority: CN
Inventors: 吴皓; 罗群; 袁铭; 杨兴朋
Original assignee: Jiaxing Yu Guang Electro Optical Technology Inc Us 62 Martin Road Concord Massachusetts 017
Current assignee: Jiaxing Yu Guang Electro Optical Technology Inc Us 62 Martin Road Concord Massachusetts 017
Priority date: 2019-10-14
Filing date: 2019-10-14
Publication date: 2021-04-27
Anticipated expiration: 2039-10-14
Also published as: CN110850668A; CN113176701B; CN113176701A

Abstract

The present disclosure relates to a projection device, comprising: a plurality of light sources configured to emit light beams of different colors; and a plurality of diffraction optical elements corresponding to the plurality of light sources and arranged in the optical paths downstream of the plurality of light sources, wherein each diffraction optical element can receive the light beams emitted by the corresponding light source and project corresponding patterns on a projection plane after modulation, and the patterns projected on the projection plane by each diffraction optical element are at least partially overlapped.

Description

Projection apparatus and pattern projection method

Technical Field

The present disclosure relates to the field of optical technology, and more particularly, to a projection apparatus including a diffractive optical element and a pattern projection method.

Background

In some automobiles or shops, a projection lamp or a projection module is used to project a LOGO or a specific pattern of a vehicle. Most of the products in the market adopt the following system architecture: the white light LED source + collimating lens (group) or collimating microlens array + mask (specific pattern or LOGO mask) + imaging lens (group) or microlens array forms a specific white light pattern or LOGO. If the mask has a partial color filtering function, a pattern of two colors or multiple colors can be realized. Such systems are typically complex and costly to construct.

The statements in this background section merely represent techniques known to the public and are not, of course, representative of the prior art.

BRIEF SUMMARY OF THE PRESENT DISCLOSURE

In view of at least one of the deficiencies of the prior art, the present disclosure provides a projection device comprising:

a plurality of light sources configured to emit light beams of different colors;

a plurality of diffractive optical elements corresponding to the plurality of light sources and arranged at the downstream of the light paths of the plurality of light sources, wherein each diffractive optical element can receive the light beams emitted by the corresponding light source and project corresponding patterns on a projection plane after modulation,

wherein the patterns projected by each of the diffractive optical elements on the projection plane at least partially coincide.

According to an aspect of the present disclosure, the plurality of diffractive optical elements include a first diffractive optical element and a second diffractive optical element arranged in parallel to each other, the plurality of light sources include a first light source and a second light source corresponding to the first diffractive optical element and the second diffractive optical element, the first diffractive optical element and the second diffractive optical element are arranged concentrically with the corresponding first light source and the second light source, respectively, an optical axis direction of the first light source and the second light source is perpendicular to the projection plane, with a pattern projected by the first diffractive optical element as a reference pattern, the pattern projected by the second diffractive optical element is made to at least partially coincide with the reference pattern by:

the second diffractive optical element is offset by an amount Δ x1 along the first direction and an amount Δ y1 along the second direction with respect to the first diffractive optical element, wherein the first direction, the second direction and the optical axis direction are mutually perpendicular two by two, and the second diffractive optical element is configured such that the pattern projected by the second diffractive optical element is offset by- Δ x1 along the first direction from the optical axis of the second light source and by- Δ y1 along the second direction.

According to an aspect of the present disclosure, the plurality of diffractive optical elements further include a third diffractive optical element, the plurality of light sources further include a third light source corresponding to the third diffractive optical element, the third diffractive optical element is disposed concentrically with the third light source, an optical axis direction of the third light source is perpendicular to the projection plane, and a pattern projected by the third diffractive optical element at least partially coincides with the reference pattern by:

the third diffractive optical element is offset relative to the first diffractive optical element by an amount Δ x2 along the first direction and by an amount Δ y2 along the second direction, the third diffractive optical element being configured such that it projects a pattern that is offset by- Δ x2 along the first direction and by- Δ y2 along the second direction from an optical axis of the third light source.

According to an aspect of the disclosure, the offsets Δ x1 and Δ y1 are larger than a package size of the second diffractive optical element and are integer multiples of a center region pixel side length of a pattern projected by the second diffractive optical element;

the offsets Δ x2 and Δ y2 are larger than a package size of the third diffractive optical element and are integer multiples of a center area pixel side length of a pattern projected by the third diffractive optical element.

According to an aspect of the present disclosure, the first diffractive optical element, the second diffractive optical element, and the third diffractive optical element are arranged in a line shape, or in a pin shape.

According to an aspect of the present disclosure, the plurality of diffractive optical elements include a first diffractive optical element and a second diffractive optical element arranged in parallel to each other, the plurality of light sources include a first light source and a second light source corresponding to the first diffractive optical element and the second diffractive optical element, the first diffractive optical element and the second diffractive optical element are arranged concentrically with the corresponding first light source and the second light source, optical axis directions of the first light source and the second light source form an angle Φ with a normal direction of the projection plane, where Φ is not equal to 90 degrees, and a pattern projected by the first diffractive optical element is taken as a reference pattern, by causing the pattern projected by the second diffractive optical element to at least partially coincide with the reference pattern:

the second diffractive optical element is offset by an amount Δ x1 in the first direction and by an amount Δ y1 in the second direction with respect to the first diffractive optical element, wherein the first direction, the second direction and the optical axis direction are mutually perpendicular two by two, the projection plane is parallel to the first direction, and the second diffractive optical element is arranged such that the pattern projected by the second diffractive optical element is offset by- Δ x1 in the first direction from the optical axis of the second light source and by- Δ y1/cos Φ in the second direction.

According to an aspect of the present disclosure, the plurality of diffractive optical elements further includes a third diffractive optical element, the plurality of light sources further includes a third light source corresponding to the third diffractive optical element, the third diffractive optical element is concentrically disposed with the corresponding third light source, the third diffractive optical element is parallel to the first and second diffractive optical elements, a pattern projected by the third diffractive optical element at least partially coincides with the reference pattern by:

the third diffractive optical element is offset relative to the first diffractive optical element by an amount ax 2 along the first direction and by an amount ay 2 along the second direction, the third diffractive optical element being configured such that it projects a pattern that is offset by-ax 2 along the first direction from an optical axis of the third light source and by-ay 2/cos phi along the second direction.

According to an aspect of the present disclosure, the plurality of diffractive optical elements includes a first diffractive optical element and a second diffractive optical element, the plurality of light sources includes a first light source and a second light source corresponding to the first diffractive optical element and the second diffractive optical element, the first diffractive optical element and the second diffractive optical element are concentrically disposed with the corresponding first light source and the second light source, an optical axis direction of the first light source is perpendicular to the projection plane, an optical axis direction of the second light source is not perpendicular to the projection plane, and an optical axis of the second light source is directed to an intersection of the optical axis of the first light source and the projection plane.

According to an aspect of the present disclosure, the plurality of diffractive optical elements further includes a third diffractive optical element, the plurality of light sources further includes a third light source corresponding to the third diffractive optical element, the third diffractive optical element is concentrically disposed with the corresponding third light source, an optical axis direction of the third light source is not perpendicular to the projection plane, and an optical axis of the third light source is directed to an intersection of the optical axis of the first light source and the projection plane.

According to an aspect of the present disclosure, the plurality of diffractive optical elements include a first diffractive optical element, a second diffractive optical element, and a third diffractive optical element, the plurality of light sources include a first light source, a second light source, and a third light source corresponding to the first diffractive optical element, the second diffractive optical element, and the third diffractive optical element, the first diffractive optical element, the second diffractive optical element, and the third diffractive optical element are concentrically disposed with the corresponding first light source, the second light source, and the third light source, an optical axis direction of the first light source, an optical axis direction of the second light source, and an optical axis direction of the third light source are not parallel to each other, and the optical axis of the first light source, the optical axis of the second light source, and the optical axis of the third light source intersect the projection plane at the same intersection point.

According to an aspect of the disclosure, the projection apparatus further includes a plurality of switches respectively connected to the plurality of light sources to individually control each of the plurality of light sources to emit light.

According to one aspect of the disclosure, the plurality of light sources includes a laser light source and/or an LED light source with a collimating lens.

According to one aspect of the present disclosure, the plurality of light sources includes a red light source, a green light source, and a blue light source.

The present disclosure also provides a pattern projection method, including:

s101: projecting a first pattern on a projection plane through a first diffractive optical element by a first light source;

s102: projecting a second pattern on the projection plane through a second diffractive optical element by a second light source;

s103: projecting a third pattern on the projection plane via a third diffractive optical element by a third light source,

wherein the first, second and third patterns are at least partially coincident on the projection plane.

According to an aspect of the present disclosure, the pattern projection method is performed by the projection apparatus as described above.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure. In the drawings:

FIG. 1 illustrates a projection device according to one embodiment of the present disclosure;

FIGS. 2A and 2B show projection diagrams of a first light source and a first diffractive optical element;

FIGS. 3A and 3B show projection diagrams of a second light source and a second diffractive optical element;

FIGS. 4A and 4B show projection diagrams of a third light source and a third diffractive optical element;

FIG. 5 illustrates a target pattern;

FIGS. 6A to 6C show a projection apparatus and a correction example in which diffractive optical elements are arranged in a homonymous manner and projected on a vertical projection plane;

FIG. 7 shows a projection apparatus and a correction example in which diffractive optical elements are arranged in a homonymous manner and projection is performed on an inclined projection plane;

FIGS. 8A to 8C show a projection apparatus and a correction example in which diffractive optical elements are arranged in a homeotropic manner and projected on a vertical projection plane;

FIGS. 9A to 9C show a projection apparatus and a correction example in which diffractive optical elements are arranged in a homeotropic manner and projected on an inclined projection plane;

FIGS. 10A to 10C show a projection apparatus and a correction example in which diffractive optical elements are arranged in a matrix and projected on a vertical projection plane;

fig. 11 shows a projection apparatus and a correction example in which diffractive optical elements are arranged in a reversed-straight shape and projection is performed on an inclined projection plane;

FIGS. 12A to 12C show a projection apparatus and a correction example in which diffractive optical elements are arranged in an inverted delta shape and projected on a vertical projection plane;

FIGS. 13A to 13C show a projection apparatus and a correction example in which diffractive optical elements are arranged in an inverted delta shape and projection is performed on an inclined projection plane; and

fig. 14 illustrates a pattern projection method according to one embodiment of the present disclosure.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art can appreciate, the described embodiments can be modified in various different ways, without departing from the spirit or scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present disclosure, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "straight", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be considered as limiting the present disclosure. Furthermore, the terms "first", "second" and "first" are used 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, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present disclosure, "a plurality" means two or more unless specifically limited otherwise.

Throughout the description of the present disclosure, it is to be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection, either mechanically, electrically, or otherwise in communication with one another; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present disclosure can be understood by those of ordinary skill in the art as appropriate.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or may comprise the first and second features being in contact, not directly, but via another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the disclosure. To simplify the disclosure of the present disclosure, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present disclosure. Moreover, the present disclosure may repeat reference numerals and/or reference letters in the various examples, which have been repeated for purposes of simplicity and clarity and do not in themselves dictate a relationship between the various embodiments and/or arrangements discussed. In addition, the present disclosure provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

The preferred embodiments of the present disclosure will be described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are merely for purposes of illustrating and explaining the present disclosure and are not intended to limit the present disclosure.

Fig. 1-5 illustrate a projection device 1 according to one embodiment of the present disclosure, described in detail below with reference to fig. 1-5. As shown in fig. 1, the projection apparatus 1 includes a light emitting unit 11 and a diffractive optical element 12, wherein the light emitting unit 11 includes a plurality of light sources capable of emitting light beams of different colors, and fig. 1 shows three light sources, respectively: a first light source 111 emitting a red light beam; a second light source 112 emitting a green light beam; and a third light source 113 emitting a blue light beam. The diffractive optical element 12 includes a plurality of diffractive optical elements corresponding to the light sources, and is disposed downstream of the light paths of the respective light sources. As shown in fig. 1, the diffractive optical element 12 includes three diffractive optical elements, a first diffractive optical element 121, a second diffractive optical element 122, and a third diffractive optical element 123, which correspond to the first light source 111, the second light source 112, and the third light source 113, respectively. Each diffractive optical element is designed for the wavelength of the corresponding light source, for example, and has a specific period and a micro-shape respectively for different wavelengths, so as to receive the light beam emitted by the corresponding light source, and project a corresponding pattern on the projection plane 2 after modulation, wherein the patterns projected on the projection plane 2 by each diffractive optical element at least partially coincide, so that a complex pattern can be projected on the projection plane by a combination of a plurality of monochromatic light sources and diffractive optical elements.

Note that three light sources and three diffractive optical elements are described as an example in the above description, and those skilled in the art will readily understand that the number of specific light sources and diffractive optical elements, and the color of the light sources can be flexibly changed, which are all within the scope of the present disclosure.

In addition, the first diffractive optical element 121, the second diffractive optical element 122, and the third diffractive optical element 123 may be three separate optical devices, or may be integrated on one substrate, as long as they can individually modulate light beams of different wavelengths, which is within the protection scope of the present disclosure. For example, three regions may be formed on one substrate, and structures of specific periods and shapes may be designed for different wavelengths, respectively, all belonging to the "plurality of diffractive optical elements" mentioned in the present disclosure.

The first light source 111, the second light source 112, and the third light source 113 are, for example, laser diodes of different colors, and the first diffractive optical element 121, the second diffractive optical element 122, and the third diffractive optical element 123 may be diffractive optical elements designed for divergent light emitted by the laser diodes, so that collimation of light emitted by the laser diodes is not required. Or alternatively, the first light source 111, the second light source 112, and the third light source 113 may also be LED light sources with different colors, the first diffractive optical element 121, the second diffractive optical element 122, and the third diffractive optical element 123 may be diffractive optical elements designed for collimating light, and a collimating lens may be added between the light sources and the diffractive optical elements, which is easily understood by those skilled in the art and is not described herein again.

The operation of the projection device 1 will now be described in detail with reference to fig. 2-5.

Fig. 5 shows a hypothetical target pattern, i.e., a white stripe pattern.

As shown in fig. 2A, a light beam emitted from the first light source 111 (red laser light source) is incident on the first diffractive optical element 121, modulated and emitted, and a pattern of red stripes as shown in fig. 2B is generated on the projection plane 2.

As shown in fig. 3A, the light beam emitted from the second light source 112 (green laser light source) is incident on the second diffractive optical element 122, and after being modulated, a pattern of green stripes as shown in fig. 3B is generated on the projection plane 2.

As shown in fig. 4A, the light beam emitted from the third light source 113 (blue laser light source) is incident on the third diffractive optical element 123, and after being modulated, a pattern of blue stripes as shown in fig. 4B is produced on the projection plane 2.

The stripe patterns of different colors shown in fig. 2B, 3B and 4B are, for example, coincident on the projection plane 2, and thus a white stripe pattern shown in fig. 5 can be synthesized. More complex patterns may be designed by those skilled in the art in light of the teachings of this disclosure.

Thus, in the present disclosure, by forming three diffraction modulation regions (or having three separate diffractive optical elements) on one sheet of substrate, structures of specific periods and shapes are designed for the wavelengths of R/G/B, respectively. The same pattern can be formed by different colors of light and the patterns of white light can be formed by completely coinciding the light on the projection plane of the target. It is also possible to form a pattern of different colors of light that are not exactly the same and at least partially coincide on the target projection plane to form a colored pattern. In addition, if the input current of each light source is individually adjusted to control the light emission intensity, a full-color pattern can be obtained. The desired pattern can be obtained by modulating the design of the structures on the DOE. Therefore, according to an embodiment of the present disclosure, the projection apparatus 1 further includes a plurality of switches (not shown) respectively connected to the plurality of light sources to individually control each of the plurality of light sources to emit light.

The structure of a projection apparatus according to a preferred embodiment of the present disclosure is described below with reference to the accompanying drawings.

Example 1

Fig. 6A to 6C show a structure of a projection apparatus according to a preferred embodiment of the present disclosure, which includes a first light source 111 (red light), a second light source 112 (green light), and a third light source 113 (blue light) arranged in a line, the optical axis directions (Z-axis direction in the drawing) of the three light sources being perpendicular to the projection plane 2. The following description will be given taking an example in which the first light source 111 is located between the second light source 112 and the third light source 113. The projection apparatus further includes a first diffractive optical element 121, a second diffractive optical element 122, and a third diffractive optical element 123 arranged in parallel, corresponding to the first light source 111, the second light source 112, and the third light source 113, respectively, and arranged concentrically with the corresponding light sources, respectively. The coordinate system is also shown in fig. 6A. In fig. 6A, each light source forms one channel with the corresponding diffractive optical element, and all the optical axis directions (Z) are perpendicular to the target projection plane 2. As shown in fig. 6B, the three diffractive optical elements are arranged in a line, and the Y coordinate and the Z coordinate are the same, and the X coordinate is different. With reference to the first diffractive element 121, the distance between the second diffractive optical element 122 and the first diffractive optical element 121 in the X direction (first direction) in the drawing is Δ X1, and the distance between the third diffractive optical element 123 and the first diffractive optical element 121 in the X direction is Δ X2. Therefore, if no correction is made, the intervals on the projection plane between the projection pattern formed by modulation by the second diffractive optical element and the projection pattern formed by modulation by the third diffractive optical element and the projection pattern formed by modulation by the first diffractive optical element are also Δ x1 and Δ x 2. In order to correct the projected pattern, the patterns projected by the second diffractive optical element 122 and the third diffractive optical element 123 may be made to at least partially coincide with the reference pattern, using the pattern projected by the first diffractive optical element 121 as the reference pattern.

The second diffractive optical element 122 is designed and manufactured such that it projects a pattern that is offset by-ax 1 along the X-direction from the optical axis of the second light source. Likewise, the third diffractive optical element 123 is designed and manufactured such that it projects a pattern that is offset by- Δ X2 along the X direction from the optical axis of the second light source. Thus, as shown in fig. 6C, after correction, the patterns projected by the three diffractive optical elements can be completely overlapped, and a synthesized target pattern can be obtained.

The above describes a projection apparatus having three light sources and three diffractive optical elements. Those skilled in the art will readily appreciate that fewer or greater numbers of light sources and diffractive optical elements may be included and are within the scope of the present disclosure. In addition, in fig. 6A to 6C, after the correction, the patterns projected by the three diffractive optical elements may completely coincide, and those skilled in the art can easily understand that the patterns projected by the three diffractive optical elements may also be at least partially coincide by the correction to achieve a specific pattern effect, which is not described herein again.

In addition, in the description of fig. 6A, 6B, and 6C, the three light sources and the three diffractive optical elements are arranged in a line, with a positional difference only in one directional dimension (X-axis direction). Those skilled in the art, given the teachings of this disclosure, may also arrange the light source and diffractive optical element in other ways, such as "zig-zag" or three diffractive optical elements parallel to each other but offset from each other in the Z-axis direction. In the case of the "pin" shape, the amount of shift in the Y direction (second direction) of the second diffractive optical element 122 with respect to the first diffractive optical element 121 is Δ Y1, and the amount of shift in the Y direction (second direction) of the third diffractive optical element 123 with respect to the first diffractive optical element 121 is Δ Y2. In this case, similarly to the above, when the second diffractive optical element 122 is designed and manufactured, the pattern projected by the second diffractive optical element is shifted by- Δ Y1 from the optical axis of the second light source along the Y direction, and when the third diffractive optical element 123 is designed and manufactured, the pattern projected by the third diffractive optical element is shifted by- Δ Y2 from the optical axis of the second light source along the Y direction, so that the correction can be achieved, which is not described herein again.

According to a preferred embodiment of the present disclosure, in determining the offset amount, the following aspects are considered: the amount of shift is preferably larger than the package size of the light source and the diffractive optical element, and further, the amount of shift is preferably an integral multiple of the side length of the pixel corresponding to the central area of the channel projection pattern. Therefore, the offsets Δ x1 and Δ y1 are larger than the package size of the second light source and the second diffractive optical element and are integer multiples of the central region pixel side length of the pattern projected by the second diffractive optical element; the offsets Δ x2 and Δ y2 are larger than the package size of the third light source and the third diffractive optical element and are integer multiples of the center area pixel side length of the pattern projected by the third diffractive optical element. The following is a detailed description of a specific embodiment.

The laser diodes of three colors of red, green and blue are still taken as an example of the light source. When the blue light wavelength is 473nm and the green light wavelength is 520nm, the side length d of the diffractive optical element is 2mm, and the projection distance L is 1000mm, then according to the formula sin θ m λ/d, the pixel side length of the blue light channel projection pattern central region (m 1) is Δ xB L sin θ L λ B/d 0.2365mm, the pixel side length of the green light channel projection pattern central region is Δ xG 0.26mm, Δ x1 should be an integer multiple of Δ xG, and Δ x2 should be an integer multiple of Δ xB, and Δ x1 Δ xG 25 is 6.5mm, Δ x2 Δ xB 30 mm may be selected in consideration of the package sizes of the laser diode and the diffractive optical element, that is, the second diffractive optical element of the green light is located at the left of the first diffractive optical element 6.5 mm; the third diffractive optical element for blue light is located 7.095mm to the right of the first diffractive optical element for red light. Correspondingly, the target pattern for green light is shifted to the right by 25 pixels on the projection plane, and the target pattern for blue light is shifted to the left by 30 pixels on the projection plane.

In the above embodiment, the optical axis direction is perpendicular to the projection plane, but the scope of the present disclosure is not limited thereto, as described in embodiment 2 below.

Example 2

Fig. 7 illustrates a manner in which the projection apparatus of the present disclosure projects on a non-perpendicular projection plane. In fig. 7, the optical axis direction Z is not perpendicular to the target projection plane, but the optical axis directions of the three channels are parallel to each other. In this case, similarly to embodiment 1, the three light sources and the three diffractive optical elements are arranged in a line parallel to the X-axis direction, and the projection plane is also parallel to the X-axis direction, so that the calculation and correction of the offset amount are the same as those described with reference to fig. 6A to 6C, and will not be described again here.

Example 3

Fig. 8A-8C illustrate a structure of a projection device according to one embodiment of the present disclosure. The first light source 111 (red light), the second light source 112 (green light), and the third light source 113 (blue light) are arranged in a zigzag pattern, and the optical axes of the three light sources (Z-axis direction in the figure) are perpendicular to the projection plane 2. The projection apparatus further includes a first diffractive optical element 121, a second diffractive optical element 122, and a third diffractive optical element 123, which are arranged in the same final shape, corresponding to the first light source 111, the second light source 112, and the third light source 113, respectively, and are arranged concentrically with the corresponding light sources, respectively. In fig. 8A, each light source forms one channel with a corresponding diffractive optical element.

The second diffractive optical element 122 is spaced from the first diffractive optical element 121 by Δ X1 and Δ Y1 in the X direction (first direction) and the Y direction (second direction), and the third diffractive optical element 123 is spaced from the first diffractive optical element 121 by Δ X2 and Δ Y2 in the X direction (first direction) and the Y direction (second direction), as shown in fig. 8B, with respect to the first diffractive optical element 121. If no correction is made, the intervals on the projection plane between the projection pattern formed by the modulation by the second diffractive optical element and the projection pattern formed by the modulation by the third diffractive optical element and the projection pattern formed by the modulation by the first diffractive optical element are also Δ x1 and Δ y1 and Δ x2 and Δ y2, respectively. Thus, in accordance with a preferred embodiment of the present disclosure, in order for the images to overlap, the second diffractive optical element 122 is designed and manufactured such that it projects a pattern that is offset from the optical axis of the second light source by- Δ X1 along the X direction and- Δ Y1 along the Y direction; the third diffractive optical element 123 is designed and manufactured such that it projects a pattern that is shifted by- Δ X2 along the X direction and- Δ Y2 along the Y direction from the optical axis of the third light source.

The amounts of offset Δ x1, Δ x2, Δ y1, and Δ y2 may be determined taking into account the fact that (i) the amount of offset is preferably larger than the package size of the light source and the diffractive optical element; the offset should be an integer multiple of the side length of the pixel corresponding to the central area of the channel projection pattern. The following description is given with reference to a specific embodiment.

The laser diodes of three colors of red, green and blue are still taken as an example of the light source. A blue light wavelength of 473nm, a green light wavelength of 520nm, a side length d of the diffractive optical element of 2mm, a projection distance L of 1000mm, then, according to the formula sin θ ═ m λ/d, the pixel side length of the central region (m ═ 1) of the blue light channel projection pattern is Δ xB ═ L ═ sin θ ═ L ═ λ B/d ═ 0.2365mm, the pixel side length of the central region of the green light channel projection pattern is Δ xG ═ 0.26mm, then ax 1, ay 1 should be integer multiples of ax g and ax 2, ay 2 should be integer multiples of ax b, taking into account the package size of the laser diode and the diffractive optical element, Δ x1 ═ Δ xG 15 ═ 3.9mm, Δ y1 ═ Δ xG 25 ═ 6.5mm, Δ x2 ═ Δ xB 20 ═ 4.73mm, Δ y2 ═ Δ xB 30 ═ 7.095mm, that is, the second diffractive optical element for green is located 3.9mm to the left and 6.5mm below the first diffractive optical element for red; the third diffractive optical element for blue light is located 4.73mm to the right and 7.095mm below the first diffractive optical element for red light. Correspondingly, the target pattern of green light is shifted by 15 pixels to the right and by 25 pixels to the up on the projection plane; the target pattern of blue light is shifted to the left by 20 pixels and to the up by 30 pixels on the projection plane. Fig. 8C shows a schematic of the pattern before correction and the pattern after correction.

Example 4

Fig. 9A to 9C show a correction example of a projection apparatus in which diffractive optical elements are aligned in a homeotropic manner and projected on an inclined projection plane according to an embodiment of the present invention. The projection device includes a first light source 111 (red light), a second light source 112 (green light), and a third light source 113 (blue light) arranged in a final shape, and the optical axes of the three light sources (Z-axis direction in the figure) are parallel to each other but not perpendicular to the projection plane. The projection apparatus further includes a first diffractive optical element 121, a second diffractive optical element 122, and a third diffractive optical element 123, which are arranged in the same final shape, corresponding to the first light source 111, the second light source 112, and the third light source 113, respectively, and are arranged concentrically with the corresponding light sources, respectively. In fig. 9A, each light source forms one channel with a corresponding diffractive optical element for three channels: a red channel, a green channel, and a blue channel.

In this case, according to a preferred embodiment of the present disclosure, it is possible to make the arrangement direction (i.e., the X-axis direction) of the green light channel and the blue light channel parallel to the projection plane, the optical axis direction (i.e., the Z-axis direction) of the three channels at an angle of Φ to the normal direction of the projection plane, and the optical axis directions of the three channels parallel to each other.

The three light sources and the three diffractive optical elements are arranged in a delta shape. The second diffractive optical element 122 is spaced from the first diffractive optical element 121 by Δ X1 and Δ Y1 in the X-axis direction (first direction) and the Y-axis direction (second direction), and the third diffractive optical element 123 is spaced from the first diffractive optical element 121 by Δ X2 and Δ Y2 in the X-axis direction (first direction) and the Y-axis direction (second direction), as shown in fig. 9B, with respect to the first diffractive optical element 121. If no correction is made, the intervals on the projection plane between the projection pattern formed by the modulation by the second diffractive optical element and the projection pattern formed by the modulation by the third diffractive optical element and the projection pattern formed by the modulation by the first diffractive optical element are Δ x1 and Δ y1/cos φ, and Δ x2 and Δ y2/cos φ, respectively, in consideration of the projection conversion relationship. Thus, in accordance with a preferred embodiment of the present disclosure, in order for the images to overlap, the second diffractive optical element 122 is designed and manufactured such that it projects a pattern that is offset from the optical axis of the second light source by- Δ X1 along the X direction and- Δ Y1/cos φ along the Y direction; the third diffractive optical element 123 is designed and manufactured such that it projects a pattern that is offset from the optical axis of the third light source by- Δ X2 along the X-direction and- Δ Y2/cos φ along the Y-direction.

According to a preferred embodiment of the present disclosure, in determining the offsets Δ x1, Δ x2, Δ y1, and Δ y2, the following factors may be considered (i) the offset is preferably larger than the package size of the light source and the diffractive optical element; the offset should be an integer multiple of the side length of the pixel corresponding to the central area of the channel projection pattern. This is illustrated in a specific embodiment.

The laser diodes of three colors of red, green and blue are still taken as an example of the light source. Phi is 60 deg., blue light wavelength 473nm, green light wavelength 520nm, side length d of the diffractive optical element is 2mm, red light channel projection distance LR is 1000mm, blue light channel projection distance LB is LR- Δ y1 tan phi, green light channel projection distance LG is LR- Δ y2 tan phi, then according to the formula sin theta is m lambda/d, blue light channel projection pattern central region (m is 1) pixel side length delta xB is LB sin theta (LR- Δ y1 phi B/d), in consideration of Δ y1< LR, Δ xB is 0.2365mm, in the same sense, green light channel projection pattern central region pixel side length delta xG is 0.26mm, Δ x1 and Δ y 7/cos phi should be integral multiple of Δ xG phi, Δ x2 x and Δ x phi should be integral multiple of Δ xG 359, Δ x and Δ x is an integral multiple of Δ xG 359, Δ x is an integral multiple of Δ x 369 and Δ x is an integral multiple of Δ x 369, Δ x and Δ x is an integral multiple of Δ x phi, Δ y1 ═ Δ xG × cos Φ 50 ═ 6.5mm, Δ x2 ═ Δ xB × 20 ═ 4.73mm, Δ y2 ═ Δ xB × cos Φ ═ 60 ═ 7.095mm, i.e., the second diffractive optical element for green is located 3.9mm to the left and 6.5mm below the first diffractive optical element for red; the third diffractive optical element for blue light is located 4.73mm to the right and 7.095mm below the first diffractive optical element for red light. Correspondingly, the target map of green light is shifted by 15 pixels to the right and by 50 pixels to the up on the projection plane; the target map for blue light is shifted 20 pixels to the left and 60 pixels upward on the projection plane.

Those skilled in the art will understand that, in the present embodiment, the first diffractive optical element 121, the second diffractive optical element 122, and the third diffractive optical element 123 may be arranged in a "pin" shape, or in a "straight" shape.

Example 5

Fig. 10A to 10C show a correction example of a projection apparatus in which diffractive optical elements are arranged in an opposite-to-one shape and projection is performed on a vertical projection plane. Where each light source is concentric with the diffractive optical element of the corresponding channel (e.g., first light source 111 (red laser diode) is concentric with first diffractive optical element 121, second light source 112 (green laser diode) is concentric with second diffractive optical element 122, and third light source 113 (blue laser diode) is concentric with third diffractive optical element 123). The optical axis ZR of the first light source 111 as a reference is perpendicular to the projection plane, but the optical axis ZG of the second light source 112 is not parallel to the optical axis ZR of the first light source 111, and the optical axis ZB of the third light source 113 is not parallel to the optical axis ZR of the first light source 111 (arranged in a different direction).

In fig. 10, the light sources and the diffractive optical element are arranged in a straight line, and the intervals in the X direction between the second light source 112 and the third light source 113 and the reference first light source are Δ X1 and Δ X2, respectively, based on the first light source 111, as shown in fig. 10B. If no optical axis direction correction is made, the intervals of the corresponding projection patterns on the projection plane are also Δ x1 and Δ x 2.

In order to overlap the images and achieve the correction, the optical axes ZB and ZG of the blue light source 113 and the green light source 112 may be non-perpendicular to the target projection plane and both directions of the optical axes may be directed to the intersection point of the optical axis ZR of the red light source 111 and the target projection plane.

When determining the directions of the optical axis ZB of the third light source 113 for blue light and the optical axis ZG of the second light source 112 for green light, the determination may be made according to the following two factors: the offset is preferably larger than the packaging sizes of the light source and the diffraction optical element; ② the direction of ZB and ZG is determined according to the spatial position relationship of the diffractive optical element, and a specific embodiment is as follows.

The laser diodes of three colors of red, green and blue are still taken as an example of the light source. If the projection distance LR of the first diffractive optical element for red light is 1000mm and Δ x1 is Δ x2 is 7mm, it can be calculated from the geometrical relationship that the angle between the optical axis ZB of the third light source 113 for blue light and the normal direction of the target plane is 0.40106 °, the angle between the optical axis ZG of the second light source 112 for green light and the normal direction of the target plane is-0.40106 °, and fig. 10C shows the pattern before correction and the pattern after correction.

Thus, according to a preferred embodiment of the present disclosure, the optical axes of the three channels may be non-parallel. For example, in which the optical axis of the first path is perpendicular to the target plane, the optical axes of the other two paths are directed to the intersection of the optical axis of the first path and the target plane, and the angle is set to a certain degree, the correction of the projected pattern can be achieved.

Further, as is readily understood by those skilled in the art, the first diffractive optical element, the second diffractive optical element, and the third diffractive optical element may be arranged in a line shape or in a pin shape.

Example 6

Fig. 11 shows an example of projection correction in which a plurality of diffractive optical elements are arranged in a matrix and projected on an inclined projection plane.

Where each light source is concentric with the diffractive optical element of the corresponding channel (e.g., first light source 111 (red LD) is concentric with first diffractive optical element 121, second light source 112 (green LD) is concentric with second diffractive optical element 122, and third light source 113 (blue LD) is concentric with third diffractive optical element 123). Here, the optical axis ZR of the first light source 111 as a reference is perpendicular to the projection plane, but the directions of the red, green and blue optical axes are not parallel to each other (arranged in opposite directions).

In this case, the arrangement direction of the laser diodes and the diffractive optical elements can be generally parallel to the projection plane, and the calculation of the inclination angle of the optical axis is consistent with that shown in fig. 10, which is not described herein again.

Example 7

Fig. 12A to 12C show a projection apparatus in which a plurality of diffractive optical elements are arranged in an inverted delta shape and projected on an inclined projection plane, and a correction example. Where each light source is concentric with the diffractive optical element of the corresponding channel (e.g., first light source 111 (red laser diode) is concentric with first diffractive optical element 121, second light source 112 (green laser diode) is concentric with second diffractive optical element 122, and third light source 113 (blue laser diode) is concentric with third diffractive optical element 123). The optical axis ZR of the first light source 111 as a reference is perpendicular to the projection plane, but the optical axis ZG of the second light source 112 is not parallel to the optical axis ZR of the first light source 111, and the optical axis ZB of the third light source 113 is not parallel to the optical axis ZR of the first light source 111 (arranged in a different direction).

The three light sources and the three diffractive optical elements are respectively arranged in a delta shape. Wherein the second diffractive optical element 122 is spaced from the first diffractive optical element 121 by Δ X1 and Δ Y1 in the X and Y directions, respectively, and the third diffractive optical element 123 is spaced from the first diffractive optical element 121 by Δ X2 and Δ Y2 in the X and Y directions, respectively, based on the first diffractive optical element 121, as shown in fig. 12B.

According to a preferred embodiment of the present disclosure, in order to overlap the images, the optical axis ZB of the third light source 113 and the optical axis ZG of the second light source 112 may be made non-perpendicular to the target projection plane when assembled, and both optical axis directions are directed to the intersection point of the optical axis ZR of the first light source 111 and the target projection plane.

According to a preferred embodiment of the present disclosure, the following factors may be considered in determining the directions of the optical axes ZB and ZG: the offset is preferably larger than the packaging sizes of the light source and the diffraction optical element; ② determining the directions of the optical axes ZB and ZG according to the spatial position relation of the diffractive optical element. The following is a detailed description of a specific embodiment.

The projection distance LR of the red light diffraction optical element is 1000mm, Δ x1 Δ x2 Δ y1 Δ y2 Δ x 7mm, and then the direction vector of the optical axis ZB is calculated according to the geometric relationship (α B0.40106 °, β B0.22918 °, γ B0 °); the direction vector of the optical axis ZG is (α G-0.40106 °, β G-0.22918 °, γ G-0 °). Fig. 12C schematically shows a pattern before correction and a pattern after correction.

Therefore, in this embodiment, the optical axis direction of the first light source, the optical axis direction of the second light source, and the optical axis direction of the third light source are not parallel to each other, and the optical axis of the first light source, the optical axis of the second light source, and the optical axis of the third light source intersect with the projection plane at the same intersection point, thereby achieving image correction.

Example 8

Fig. 13 shows a projection apparatus in which a plurality of diffractive optical elements are arranged in an inverted delta shape and projected on an inclined projection plane, and a correction example. Where each light source is concentric with the diffractive optical element of the corresponding channel (e.g., first light source 111 (red laser diode) is concentric with first diffractive optical element 121, second light source 112 (green laser diode) is concentric with second diffractive optical element 122, and third light source 113 (blue laser diode) is concentric with third diffractive optical element 123). Here, the optical axis ZR of the first light source 111 as a reference is perpendicular to the projection plane, but the directions of the red, green and blue optical axes are not parallel to each other (arranged in opposite directions).

For design convenience, according to a preferred embodiment of the present invention, the arrangement directions (i.e., X-axis directions) of the second channel of green light and the third channel of blue light (G channel and B channel) are parallel to the projection plane, and the optical axis ZR of the red light channel is at an angle phi with respect to the normal direction of the projection plane, but the directions of the red, green and blue optical axes are not parallel to each other (arranged in opposite directions).

The three light sources and the three diffractive optical elements are respectively arranged in a delta shape. Wherein the second diffractive optical element 122 is separated from the first diffractive optical element 121 by Δ X1 and Δ Y1 in the X and Y directions, respectively, and the third diffractive optical element 123 is separated from the first diffractive optical element 121 by Δ X2 and Δ Y2 in the X and Y directions, respectively, based on the first diffractive optical element, as shown in fig. 12B.

According to a preferred embodiment of the present disclosure, in order to allow the images to overlap, the optical axis ZB and the optical axis ZG are both directed to the intersection point of the optical axis ZR and the target projection plane when assembled.

According to a preferred embodiment of the present disclosure, the directions of ZB and ZG are determined according to the following factors: the offset is preferably larger than the packaging sizes of the light source and the diffraction optical element; ② determining the directions of the optical axes ZB and ZG according to the spatial position relation of the diffractive optical element. One specific example is as follows.

Assuming that Φ is 60 °, the projection distance LR of the red DOE is 1000mm, Δ x1 is Δ x2 is 4mm, and Δ y1 is Δ y2 is 7mm, the direction vector of ZB is (α B0.40106 °, β B0.22918 °, γ B is 0 °), which can be calculated from the geometric relationship; the direction vector of ZG is (α B-0.40106 °, β B-0.22918 °, γ B-0 °). Fig. 13C schematically shows a pattern before correction and a pattern after correction.

FIG. 14 illustrates a pattern projection method 100 according to another aspect of the present disclosure. As shown in fig. 14, the pattern projection method 100 includes:

in step S101: projecting a first pattern on a projection plane through a first diffractive optical element by a first light source;

in step S102: projecting a second pattern on the projection plane through a second diffractive optical element by a second light source;

in step S103: projecting a third pattern on the projection plane via a third diffractive optical element by a third light source,

The pattern projection method 100 described above may be performed by the projection apparatus 1 described above, for example.

The projection device and the pattern projection method of the application can be applied to various occasions, for example, the projection device and the pattern projection method can be applied to LOGO or specific pattern projection lamps or modules of automobiles or shops and the like, and patterns formed by light beams of light sources of multiple colors are combined to form white light or full-color patterns or LOGO by adopting the diffractive optical element. The present invention uses a new approach to achieve the projection of white light patterns or LOGO, and in some embodiments, the mask can be eliminated, the number of lenses (groups) can be reduced, the system can be simplified, and the cost can be reduced. Compared with the projection device in the prior art, the technical scheme of the disclosure has the advantages of simple structure and low cost.

Finally, it should be noted that: although the present disclosure has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the disclosure. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A projection device, comprising:

a plurality of diffractive optical elements corresponding to the plurality of light sources, disposed downstream in an optical path of the plurality of light sources, the plurality of diffractive optical elements including a first diffractive optical element and a second diffractive optical element disposed in parallel with each other, the plurality of light sources including a first light source and a second light source corresponding to the first diffractive optical element and the second diffractive optical element, the first diffractive optical element and the second diffractive optical element being disposed concentrically with the corresponding first light source and the second light source, respectively, and an optical axis direction of the first light source and the second light source being perpendicular to a projection plane, wherein each diffractive optical element can receive a light beam emitted from the corresponding light source, and projects a corresponding pattern on a projection plane after modulation,

wherein the pattern projected by each diffractive optical element on the projection plane at least partially coincides, and the pattern projected by the second diffractive optical element at least partially coincides with the reference pattern by taking the pattern projected by the first diffractive optical element as the reference pattern:

the second diffractive optical element is offset by an amount Δ x1 in a first direction and an amount Δ y1 in a second direction with respect to the first diffractive optical element, wherein the first direction, the second direction and the optical axis direction are mutually perpendicular two by two, and the second diffractive optical element is arranged such that the pattern it projects is offset by- Δ x1 in the first direction from the optical axis of the second light source and by- Δ y1 in the second direction.

2. The projection apparatus according to claim 1, wherein the plurality of diffractive optical elements further comprises a third diffractive optical element, the plurality of light sources further comprises a third light source corresponding to the third diffractive optical element, the third diffractive optical element is concentrically disposed with the third light source, an optical axis direction of the third light source is perpendicular to the projection plane, and a pattern projected by the third diffractive optical element is at least partially coincident with the reference pattern by:

3. The projection apparatus of claim 2 wherein the offsets Δ x1 and Δ y1 are larger than a package size of the second diffractive optical element and are integer multiples of a center region pixel side length of a pattern projected by the second diffractive optical element;

4. The projection apparatus according to claim 3, wherein the first diffractive optical element, the second diffractive optical element, and the third diffractive optical element are arranged in a line, or in a delta.

5. The projection device of any of claims 1-4, further comprising a plurality of switches respectively connected to the plurality of light sources to individually control each of the plurality of light sources to emit light.

6. The projection apparatus according to any one of claims 1-4, wherein the plurality of light sources comprises a laser light source and/or an LED light source with a collimating lens.

7. The projection device of any of claims 1-4, wherein the plurality of light sources comprises a red light source, a green light source, and a blue light source.

8. A projection device, comprising:

a plurality of diffractive optical elements corresponding to the plurality of light sources, disposed downstream in an optical path of the plurality of light sources, wherein the plurality of diffractive optical elements include a first diffractive optical element and a second diffractive optical element disposed in parallel with each other, the plurality of light sources include a first light source and a second light source corresponding to the first diffractive optical element and the second diffractive optical element, the first diffractive optical element and the second diffractive optical element are disposed concentrically with the corresponding first light source and the second light source, and an optical axis direction of the first light source and the second light source forms an angle phi with a normal direction of a projection plane, wherein phi is not equal to 90 degrees, wherein each diffractive optical element can receive a light beam emitted by the corresponding light source, and projects a corresponding pattern on the projection plane after modulation,

the second diffractive optical element is offset by an amount Δ x1 in a first direction and by an amount Δ y1 in a second direction with respect to the first diffractive optical element, wherein the first direction, the second direction and the optical axis direction are mutually perpendicular in pairs, the projection plane is parallel to the first direction, and the second diffractive optical element is arranged such that the pattern projected by the second diffractive optical element is offset by- Δ x1 in the first direction from the optical axis of the second light source and by- Δ y1/cos Φ in the second direction.

9. The projection apparatus of claim 8, wherein the plurality of diffractive optical elements further comprises a third diffractive optical element, the plurality of light sources further comprises a third light source corresponding to the third diffractive optical element, the third diffractive optical element is disposed concentrically with the corresponding third light source, the third diffractive optical element is parallel to the first and second diffractive optical elements, the pattern projected by the third diffractive optical element at least partially coincides with the reference pattern by:

10. The projection apparatus according to claim 9, wherein the first, second and third diffractive optical elements are arranged in a "straight" or "pinkish" pattern.

11. The projection device of any of claims 8-10, further comprising a plurality of switches respectively connected to the plurality of light sources to individually control each of the plurality of light sources to emit light.

12. The projection apparatus according to any of claims 8-10, wherein the plurality of light sources comprises a laser light source and/or an LED light source with a collimating lens.

13. The projection device of claim 8 or 10, wherein the plurality of light sources comprises a red light source, a green light source, and a blue light source.

14. A pattern projection method performed by the projection apparatus according to any one of claims 1 to 13, the pattern projection method comprising: