Patent ID: 12235180

Reference number: rigid support1, oscillating mirror2, laser light source3, projection plane4, scan controller5, laser beam11, normal plane12, reflected beam13, scan line segment pattern14, additive substrate8, first scan line31, second scan line32.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

A phase alignment system of oscillating mirror, comprising: laser light source, oscillating mirror and scan controller. In one or more embodiments, as shown inFIG.1, an oscillating mirror2is provided on the base of the rigid support1, a laser light source3is provided on the rigid support1, the laser beam emitted by the laser light source3is directed to the center position of the micro oscillating mirror2, and illuminated on the projection plane4after being reflected. The projection plane4is parallel to oscillating mirror2in static state. The schematic diagram of the optical path is shown inFIG.2. The laser beam11emitted by the laser light source3is located in the normal plane12drawn from the torsion axis of the oscillating mirror2, and the reflected beam13reflected by the oscillating mirror2is directed toward the projection plane4.

During scanning, the scan controller sends out an electrical excitation signal according to the inherent frequency of the oscillating mirror and applies it to an oscillating mirror driving mechanism through a signal line. Preferably, the oscillating mirror driving mechanism includes an electrostatic electrode or an electromagnetic coil.

In one or more embodiments, as shown inFIG.2, the oscillating mirror2can be deflected clockwise or counterclockwise under the drive of the driving mechanism; meantime, the scan controller outputs a beam switch signal to the laser light source3, and the reflected beam13of the laser beam11reflected by the oscillating mirror2scans on the projection plane4to form a scan line pattern14.

The specific scanning method is shown on the left side ofFIG.3. When the oscillating mirror2is in the counterclockwise limit position, the scanning point21of the reflected beam13in the projection plane4is located on the leftmost side, and then the oscillating mirror2scans in the clockwise direction and the scanning point21moves from left to right. As shown on the right side ofFIG.3, when the oscillating mirror2is in the clockwise limit position, the scanning point21of the reflected beam13in the projection plane4is located on the rightmost side, and then the micro oscillating mirror2scans counterclockwise, and the scan point21moves from right to left. When the micro oscillating mirror2performs continuous simple harmonic oscillation, the clockwise scanning and the counterclockwise scanning are performed alternately, the scanning point21moves from left to right on the projection plane4, also alternating with the scanning movement from right to left.

In one or more embodiments, the continuous scan line segment14is a line pattern whose length can be equally divided and quantified into 2n pixels. When the oscillating mirror starts to deflect clockwise from the limit position, the reflected beam13scans the 1st to the 2nth pixels on the projection plane in sequence. The reflected beam13scans the 2nth to the 1st pixels on the projection plane in sequence when the oscillating mirror starts to deflect counterclockwise from the limit position.

In the above embodiment, when the oscillating mirror starts to deflect clockwise or counterclockwise, the scan controller5can also determine the phase of the electrical excitation signal and the applied phase difference parameter, calculate the instantaneous deflection angle of the oscillating mirror2, and calculate the pixel point where the spot instantaneously scanned by reflected beam13is located according to the geometric parameters of the optical path shown inFIG.2, and then obtain the brightness value of the pixel by indexing from the scanning pattern data, and transmit the laser brightness data corresponding to the pixel to the laser light source3to control the output of the laser beam11with corresponding brightness, to reflect to the projection plane4, so as to obtain the desired pixel pattern.

During alignment, constructing a first scan line and a second scan line; matching, by the scan controller, the first scan line to the clockwise scan stage of the oscillating mirror and matching the second scan line to the counterclockwise scan stage of the oscillating mirror, making scan sequentially.

The first scan line and the second scan line are selected from line patterns, and may also be selected from at least one of simple geometric patterns such as rectangles and triangles, or a combination of the foregoing patterns, as long as the pattern can be easily detected by light and dark brightness.

In one or more embodiments, the first scan line is a line pattern in which the (m+1)th to nth pixels are ON and the remaining pixels are OFF; the second scan line is a line pattern in which the (2n−m)th to (n+1)th pixels are ON and the remaining pixels are OFF, wherein n is a positive integer, m is zero or a positive integer, m is less than n, and (n+1) is less than (2n−m).

In one embodiment, the first scan line is a line pattern in which the 1st to nth pixels are ON and the remaining pixels are OFF, and the second scan line is a line pattern in which the 2n to (n+1)th pixels are ON and the remaining pixels are OFF. That is, n is a positive integer and m is 0. In the clockwise scanning stage of the oscillating mirror, scanning the 1st to nth pixels (that is, the first scan line) in sequence; in the counterclockwise scanning stage of the oscillating mirror, scanning the 2n to (n+1)th pixels (that is, the second scan line) in sequence.

Preferably, the first scan line is a line pattern in which the n/2+1 to nth pixels are ON and the remaining pixels are OFF; the second scan line is a line pattern where the 3n/2 to n+1th pixels are ON and the remaining pixels are OFF Line pattern. That is, n is a positive even number, m=n/2. In the clockwise scanning phase of the oscillating mirror, scanning the n/2+1 to nth pixels (that is, the first scan line) in sequence; in the counterclockwise scanning phase of the oscillating mirror, scanning the 3n/2 to (n+1)th pixels (that is, the second scan line) in sequence.

During the continuous alternating scanning process, detecting the relative position of the scanned first scan line and the second scan line, and adjusting the phase difference parameter of the scan controller. Wherein, the relative positions of the first scan line and the second scan line include three states: partial overlap, mutual separation, and end-to-end connection.

As shown inFIGS.5A to5C, when the phase difference parameter applied by the scan controller is leading the actual phase of the oscillating mirror, the oscillating mirror scans the resulting first scan line31clockwise and deviates from the center line of the projection plane4to the left, and the oscillating mirror scans the resulting second scan line32counterclockwise and deviates from the center line of the projection plane4to the right. The first scan line31and the second scan line32are separated from each other, as shown inFIG.5A. Conversely, when the phase difference parameter applied by the scan controller lags behind the actual phase of the oscillating mirror, the oscillating mirror scans the resulting first scan line31clockwise, with the right end thereof passing through the center line of the projection plane4to the right, and the oscillating mirror scans the resulting second scan line32counterclockwise, with the left end thereof passing through the center line of the projection plane4to the left, and the right end of the first scan line31partially overlaps with the left end of the second scan line32, as shown inFIG.5B. When and only if the phase difference parameter applied by the scan controller is consistent with the actual phase of the oscillating mirror, the right end of the first scan line31and the left end of the second scan line32are just connected end to end, as shown inFIG.5C, so as to be spliced into a continuous projection line33with uniform brightness.

Therefore, when adjusting the phase difference parameter of the scan controller according to the relative position of the first scan line and the second scan line, when the relative position of the first scan line and the second scan line are partially overlapped, adjusting phase difference parameter of the scan controller to the leading direction; and when the relative positions of the first scan line and the second scan line are separated from each other, adjusting the phase difference parameter of the scan controller in the lagging direction.

The technical solution of the present invention also includes a phase alignment method of oscillating mirror, and the method comprises the following steps:

S01. constructing a first scan line and a second scan line;

S02. deflecting the oscillating mirror in a clockwise direction, and sequentially scanning, by the laser beam, the pixels on the first scan line on the projection plane; deflecting the oscillating mirror in a counterclockwise direction, and sequentially scanning, by the laser beam, the pixels on the second scan line on the projection plane;

S03. Detecting the relative position of the scanned first scan line and the second scan line;

S04. adjusting the phase difference parameter of the scan controller according to the detected relative position of the first scan line and the second scan line. Specifically, when the relative position of the first scan line and the second scan line is partially overlap, adjusting the phase difference parameter of the scan controller in the leading direction; when the relative positions of the first scan line and the second scan line is mutual separation, adjusting the phase difference parameter of the scan controller in the lagging direction;

S05. when the relative positions of the first scan line and the second scan line are adjusted to the end-to-end state, the phase alignment of the oscillating mirror is completed.

In one or more embodiments, the first scan line and the second scan line in the step01are selected from line patterns, and may also be selected from at least one of simple geometric patterns such as rectangles and triangles, or a combination of the foregoing patterns, as long as the pattern can be easily detected by light and dark brightness.

In one or more embodiments, the first scan line is a line pattern in which the (m+1)th to nth pixels are ON and the remaining pixels are OFF; the second scan line is a line pattern in which the (2n−m)th to (n+1)th pixels are ON and the remaining pixels are OFF, wherein n is a positive integer, m is zero or a positive integer, m is less than n, and (n+1) is less than (2n−m).

In one embodiment, the first scan line is a line pattern in which the 1st to nth pixels are ON and the remaining pixels are OFF, and the second scan line is a line pattern in which the 2n to (n+1)th pixels are ON and the remaining pixels are OFF. That is, n is a positive integer and m is 0. In the clockwise scanning stage of the oscillating mirror, scanning the 1st to nth pixels (that is, the first scan line) in sequence; in the counterclockwise scanning stage of the oscillating mirror, scanning the 2n to (n+1)th pixels (that is, the second scan line) in sequence.

Preferably, the first scan line is a line pattern in which the n/2+1 to nth pixels are ON and the remaining pixels are OFF; the second scan line is a line pattern where the 3n/2 to n+1th pixels are ON and the remaining pixels are OFF Line pattern. That is, n is a positive even number, m=n/2. In the clockwise scanning phase of the oscillating mirror, scanning the n/2+1 to nth pixels (that is, the first scan line) in sequence; in the counterclockwise scanning phase of the oscillating mirror, scanning the 3n/2 to (n+1)th pixels (that is, the second scan line) in sequence.

In one or more embodiments, steps S03to S05are specifically shown inFIGS.5A to5C. If it is detected that the first scan line31and the second scan line32are in the state of mutual separation, as shown inFIG.5A, then adjusting the phase difference parameter applied by the scan controller in the lagging direction until the two bright line segments are just connected end-to-end, as shown inFIG.5C. That is, the alignment of the phase difference parameter applied by the scan controller relative to the actual phase of the oscillating mirror is completed. If it is detected that the first scan line31and the second scan line32are in a partially overlapping state, as shown inFIG.5B, then adjusting the phase difference parameter applied by the scan controller in the leading direction until the two bright line segments are completely separated, and then adjusting the phase difference parameter of the scan controller in the lagging direction until the two bright line segments are just connected end-to-end, as shown inFIG.5C, that is, the alignment of the phase difference parameter applied by the scan controller relative to the actual phase of the oscillating mirror is completed.

The present invention utilizes the reciprocating scanning symmetry feature of the simple harmonic oscillation motion of the oscillating mirror to construct scanning pattern data with complementary pixel brightness. Only when the phase difference parameter applied by the scan controller is consistent with the actual phase of the simple harmonic oscillation of the oscillating mirror, the pattern data with complementary pixel brightness and darkness can accurately match the reciprocating motion of the oscillating mirror, and a perfect stitched continuous scanning line with uniform brightness is obtained on the projection plane, thereby achieving the effect of being clearly distinguishable and easy to detect. Furthermore, a continuous and uniformly-bright scanning line after perfect stitching is obtained on the projection plane, so as to achieve the effect of being clearly distinguishable and easy to detect. The splicing continuity of the scanning pattern on the projection plane of the present invention has no relation with the installation parallelism and distance of the projection plane relative to the oscillating mirror, and the position and attitude deviation of the projection plane does not affect the phase alignment accuracy of the oscillating mirror.

The method of the present invention for judging the splicing state of the reciprocating scanning pattern can also be directly observed and judged by human eyes in addition to using optical sensitive devices, such as digital cameras, etc., as long as the oscillating mirror's reciprocating oscillation motion is symmetrical, and the scanning frequency exceeds the minimum frequency required by the human eye's visual residual.

The above are only preferred embodiments of the present invention, and not any formal limits to the technical solutions of the present invention. Any simple modification, form change and modification to the above embodiments according to the technical essence of the present invention shall fall into the protection scope of the present invention.