CN117782907A - Laser particle analyzer and centering method thereof - Google Patents

Abstract

The invention discloses a laser particle size analyzer and a centering method thereof, wherein the laser particle size analyzer comprises: the detector comprises a detector center point, a plurality of first detection bands distributed at intervals and a plurality of second detection bands distributed at intervals; the first detection bands and the second detection bands are symmetrically distributed on the left side and the right side of the center point of the detector; each first detection zone is marked with a first mark; each second detection zone is marked with a second mark; a laser device for emitting a detection laser beam to the detector; and the moving device is used for moving the detector. According to the invention, the detection zone on the detector is divided into the first detection zone and the second detection zone which are symmetrically distributed, and the first mark and the second mark are used for distinguishing, so that when the light spot appears on the detector, the moving direction of the light spot can be judged according to the mark of the detection zone where the light spot is positioned, and the centering efficiency is improved. In addition, the invention can automatically center according to the light spot position, and compared with manual centering, the invention has the advantages of higher speed and higher efficiency.

Description

Laser particle analyzer and centering method thereof

Technical Field

The invention belongs to the field of laser particle sizers, and particularly relates to a laser particle sizer and a centering method thereof.

Background

The laser particle size analyzer irradiates laser on the particles to be measured to scatter, then receives scattered light energy by using a detector consisting of photodiode matrixes which are sequentially and annularly arranged according to angles, further obtains the relative angles of the scattered light and the incident beam of the laser, and finally obtains the particle size of the particles to be measured through inversion of the angles. Therefore, the laser beam can be aligned to the center point of the detector every time, the computer can reverse the particle size through the scattering angle, otherwise, the obtained scattering angle and the angle designed in advance are not corresponding, the actually obtained scattering angle does not accord with the scattering angle calculated by Mie scattering, and the particle size can not be correctly inverted.

The conventional laser particle sizer is configured to manually adjust a fourier lens or photocell on an optical path to adjust the relative positions of the detection laser beam and the detector, and to move a light spot formed by the detection laser beam on the detector to the center of the detector. The manual centering has two disadvantages, namely slow manual centering speed and low manual adjustment accuracy; secondly, the distribution of the detector arrays is designed into annular closed-loop distribution, when the light spot of the laser appears at any position of any detector array, the moving direction of the light spot cannot be accurately judged, because in a detector with annular distribution, the position of the light spot is inaccurately judged only by the light energy detected by the detector, and because the light spot is possibly positioned at any position of four quadrants on the same detection ring, the centering efficiency is lower.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides the laser particle analyzer and the centering method thereof, which can automatically center and easily judge the position of the light spot on the detector for the first time, thereby improving the centering efficiency and precision of the laser particle analyzer.

In a first aspect, an embodiment of the present invention discloses a laser particle sizer, comprising:

the detector comprises a detector center point, a plurality of first detection bands distributed at intervals and a plurality of second detection bands distributed at intervals; the plurality of first detection bands and the plurality of second detection bands are symmetrically distributed on the left side and the right side of the center point of the detector; each first detection zone is marked with a first mark; each second detection zone is marked with a second mark;

a laser device for emitting a detection laser beam to the detector;

and the moving device is used for moving the detector.

In some embodiments of the invention, the first detection zone is disposed to the left of the detector center point and the second detection zone is disposed to the right of the detector center point; the first marks are odd marks sequentially increasing from a direction close to the center point of the detector to a direction far from the center point of the detector, and the second marks are even marks sequentially increasing from the direction close to the center point of the detector to the direction far from the center point of the detector.

In some embodiments of the invention, the first detection zone and the second detection zone comprise a matrix of a plurality of photodiodes.

In some embodiments of the invention, the first and second detection zones are in a fan-shaped distribution; the areas of all the first detection zones are sequentially increased from the direction from the center point of the detector to the direction away from the center point of the detector; the areas of all the second detection zones are sequentially increased from the direction from the center point of the detector to the direction away from the center point of the detector; the distance between each two first detection bands increases from the direction close to the center point of the detector to the direction far from the center point of the detector; the distance between each two second detection bands increases from the direction approaching the center point of the detector to the direction separating from the center point of the detector.

In some embodiments of the invention, the mobile device comprises a stepper motor and a mobile platform; the stepping motor is used for driving the mobile platform to move; the detector is arranged on the mobile platform.

In a second aspect, an embodiment of the present invention discloses a method for centering a laser particle size analyzer, which is applied to the laser particle size analyzer described in the embodiment of the above aspect, and the centering method includes;

the laser device emits a detection laser beam to the detector;

acquiring light energy detected by each first detection zone and each second detection zone, and determining the first detection zone or the second detection zone which is larger than a first threshold value and closest to the center point of the detector as a target detection zone;

determining the moving direction of the detector according to the first mark or the second mark marked on the target detection belt, and moving the detector towards the moving direction through a moving device until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection belts and all the second detection belts;

and the moving device moves the detector upwards or downwards along the vertical direction until the light energy detected by the center point of the detector is the maximum value in the vertical direction, so that centering is completed.

In some embodiments of the present invention, the step of acquiring the optical energy detected by each first detection zone and each second detection zone, determining the first detection zone or the second detection zone that is closest to the center point of the detector and that is larger than a first threshold, as a target detection zone, further includes:

if the light energy detected by each first detection band and each second detection band is smaller than the first threshold value, the detector is moved upwards or downwards along the vertical direction by the moving device until the first detection band or the second detection band with the detected light energy larger than the first threshold value exists.

In some embodiments of the present invention, if the optical energy detected by each of the first detection zone and each of the second detection zone is less than the first threshold, moving the detector upward or downward by the moving device in a vertical direction until the optical energy detected by any of the first detection zone or the second detection zone is greater than the first threshold, the method comprises:

the moving device moves the detector upwards or downwards along the vertical direction according to a preset step length;

and if the light energy detected by each first detection band and each second detection band is still smaller than a first threshold value after the detector moves for a preset number of times, modifying the preset step length, and returning to the step of moving the detector upwards or downwards along the vertical direction by the moving device according to the preset step length until the first detection band or the second detection band with the detected light energy larger than the first threshold value exists.

In some embodiments of the invention, the first detection zone is disposed to the left of the detector center point and the second detection zone is disposed to the right of the detector center point; the first marks are odd marks which are sequentially increased from the direction close to the center point of the detector to the direction far from the center point of the detector, and the second marks are even marks which are sequentially increased from the direction close to the center point of the detector to the direction far from the center point of the detector; the step of determining the moving direction of the detector according to the first mark or the second mark marked on the target detection belt, and moving the detector towards the moving direction by a moving device until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection belt and all the second detection belt comprises the following steps:

judging the moving direction of the detector according to the odd number mark or the even number mark marked on the target detection belt;

if the target detection zone is marked with the odd number, the moving device moves the detector leftwards until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection zone and the second detection zone;

or if the even number marks are marked on the target detection zone, the moving device moves the detector rightwards until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection zone and the second detection zone.

In some embodiments of the present invention, the moving device moves the detector upward or downward along a vertical direction until the light energy detected by the center point of the detector is a maximum value in the vertical direction, and the step of centering is completed, including:

the moving device moves the detector upwards or downwards along the vertical direction and records the light energy detected by the center point of the detector after the movement;

after each movement, comparing the light energy detected by the center point of the detector twice recorded before and after the movement;

if the value of the light energy detected by the detector center point in the last time is smaller than the value of the light energy detected by the detector center point in the last time, the moving device continues to move the detector in the same direction, or if the value of the light energy detected by the detector center point in the last time is larger than the value of the light energy detected by the detector center point in the last time, the moving device moves the detector in the opposite direction until the light energy detected by the detector center point is the maximum value in the vertical direction, and centering is completed.

The laser particle analyzer and the centering method thereof have at least the following beneficial effects: according to the invention, the detection zone on the detector is divided into the first detection zone and the second detection zone which are symmetrically distributed, and the first mark and the second mark are used for distinguishing, so that the moving direction of the light spot can be judged according to the mark of the detection zone where the light spot is located when the light spot appears on the detector, and the low centering efficiency caused by uncorrelated ring numbers and positions of the detection zones on the detector is avoided. In addition, the invention also provides a mobile device which can automatically center according to the light spot position, and compared with manual centering, the mobile device has the advantages of higher speed and higher efficiency.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram of a conventional laser particle sizer detection zone;

FIG. 2 is a schematic diagram of the detection zone of a laser particle sizer according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a mobile device according to an embodiment of the invention;

FIG. 4 is a schematic block diagram of a method of centering a laser particle sizer according to an embodiment of the invention;

FIG. 5 is a schematic diagram of a complete flow chart of a method of centering a laser particle analyzer according to an embodiment of the invention.

Reference numerals: solid circle a, hollow circle b, first probe zone 100, second probe zone 200, probe center point 300, and mobile platform 400.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

In the description of the present invention, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, a plurality means one or more, and a plurality means two or more, and it is understood that greater than, less than, exceeding, etc. does not include the present number, and it is understood that greater than, less than, within, etc. include the present number. The description of first, second or third is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.

In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present invention can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

Referring to fig. 1, the rings of the photo detectors of the conventional laser particle sizer are distributed in a semicircular shape, each ring occupies a semicircle and is unfolded outwards, which causes a disadvantage in centering, for example, when centering, whether a light spot is at the left or right of the detector cannot be judged, for example, as shown in fig. 1, the light energy detected by the 7-ring detection band is the largest, and because the detection band is symmetrically distributed, the position of a solid circle a in fig. 1 or the position of a hollow circle b in fig. 1 is possible, and because the position of the light spot cannot be judged by naked eyes only according to the intensity of the light energy detected by the detector, the detector of the conventional laser particle sizer cannot judge whether the light spot is at the position of a solid circle a or a hollow circle b in fig. 1, and cannot judge the moving direction.

According to the invention, the detection zone on the detector is divided into the first detection zone and the second detection zone which are symmetrically distributed, and the first mark and the second mark are used for distinguishing, so that the moving direction of the light spot can be judged according to the mark of the detection zone where the light spot is located when the light spot appears on the detector, and the low centering efficiency caused by uncorrelated ring numbers and positions of the detection zones on the detector is avoided. In addition, the invention also provides a mobile device which can automatically center according to the light spot position, and compared with manual centering, the mobile device has the advantages of higher speed and higher efficiency.

The laser particle sizer and the centering method of the laser particle sizer according to the embodiments of the present invention are further described below based on the drawings.

Referring to fig. 2, fig. 2 is a schematic diagram of a detection zone of a laser particle analyzer according to an embodiment of the present invention, and the laser particle analyzer specifically includes:

a detector comprising a detector center point 300, a plurality of first detection zones 100 spaced apart, and a plurality of first detection zones 200 spaced apart; the plurality of first detecting bands 100 and the plurality of first detecting bands 200 are symmetrically distributed on the left and right sides of the detector center point 300; each first detection zone 100 is marked with a first marker; each first detection zone 200 is marked with a second marker;

a laser device for emitting a detection laser beam to the detector;

and the moving device is used for moving the detector.

It should be noted that, as shown in fig. 2, for the situation that the conventional laser particle analyzer cannot accurately determine the moving direction during centering, the present invention divides the detecting band on the detector into the first detecting band 100 and the first detecting band 200, and the marks marked by the first detecting band 100 and the first detecting band 200 respectively, so that the subsequent moving direction of the light spot can be immediately obtained after the position of the light spot on the detector is obtained, thereby improving the centering efficiency. Further, since the positions of the laser device and the detector are opposite, moving the detector by the moving device according to the embodiment of the present invention may be equivalent to changing the position of the spot on the detector by moving the laser device. Further, the center point 300 of the detector is not a geometric point, in fact, in some embodiments of the present invention, the center point 300 of the detector is a circular hole with a diameter of 200um, and the spot formed by the detection laser beam emitted by the laser device is a circular spot with a diameter of 50um, so that the circular spot with a diameter of 50um only needs to fall into the circular hole with a diameter of 200um completely during centering, and the geometric center of the spot does not need to be aligned with the geometric center of the center point 300 of the detector.

Referring to fig. 2, in some embodiments of the present invention, a first detection zone 100 is disposed to the left of a detector center point 300 and a second detection zone 200 is disposed to the right of the detector center point 300; the first marks are odd numbered sequentially increasing from the direction closer to the detector center point 300 to the direction farther from the detector center point 300, and the second marks are even numbered sequentially increasing from the direction closer to the detector center point 300 to the direction farther from the detector center point 300

It should be noted that, each first detecting band is marked with an odd number, and each second detecting band is marked with an even number, so that a tester or the control module can quickly determine the direction in which the light spot needs to move according to the parity of the detecting band marks when the light spot falls on the detecting band. Further, the first mark and the second mark of the present invention are not limited to the odd number mark or the even number mark, but may be other related parameters capable of distinguishing the first detection zone from the second detection zone.

In some embodiments of the present invention, the first detection zone 100 and the first detection zone 200 comprise a matrix of a plurality of photodiodes.

It should be noted that, in the embodiment of the present invention, the matrix formed by the photodiodes is used to detect the light energy of the light spot formed on the detector by the laser device. It will be appreciated that the first probe belt 100 and the first probe belt 200 may be replaced equivalently by other devices capable of detecting light energy.

Referring to fig. 2, in some embodiments of the present invention, the first detection zone 100 and the first detection zone 200 are in a fan-shaped distribution; the areas of all the first detecting strips 100 are sequentially increased from the direction approaching the center point 300 of the detector to the direction separating from the center point 300 of the detector; the areas of all the first detecting strips 200 are sequentially increased from the direction approaching the center point 300 of the detector to the direction separating from the center point 300 of the detector; the interval between each first detecting band 100 increases from the direction approaching the detector center point 300 to the direction separating from the detector center point 300; the spacing between each first detection zone 200 increases sequentially from a direction closer to the detector center point 300 to a direction farther from the detector center point 300.

It should be noted that, as shown in fig. 1, there is a problem in the conventional detector of the laser particle sizer when centering, for example, it is assumed that the position of the maximum light energy of the light spot is in the 11 rings in fig. 1, at this time, the light energy detected by the 10 rings after the centering is first moved to any direction (up, down, left, right), but the light energy detected by other rings is weakened, and there is no significant change in the light energy detected by other rings, because there is a gap between each detection ring of the conventional detector of the laser particle sizer, if the position of the light spot after the centering is in the gap between the detection rings, the experimenter cannot determine whether the light spot is moved out of the detection area (i.e. beyond the 10 rings) or moved into the gap between the detection rings after the centering, and the next movement plan cannot be determined. In the embodiment of the present invention, referring to fig. 2, since the first detecting band 100 and the first detecting band 200 are in a fan-shaped distribution, when any first detecting band 100 or first detecting band 200 can detect light energy and move up or down along the vertical direction, if the detecting band cannot detect light energy, only the moving distance is too large, so that the light spot moves out of the detection area; further, referring to fig. 2, because of the distribution of the areas and pitches of the first detection bands 100 and the areas and pitches of the first detection bands 200 and the trend of the changes of the first detection bands 100 and the first detection bands 200 themselves, when any one of the first detection bands 100 or 200 can detect light energy, if the detection bands cannot detect light energy, only light spots fall in the gaps between the detection bands when the detection bands move leftwards or rightwards in the horizontal direction. Therefore, in the above-described distribution of the first probe belt 100 and the first probe belt 200 of the embodiment of the present invention, uncertainty factors occurring in centering are reduced, and centering efficiency can be improved.

Referring to fig. 3, in some embodiments of the invention, the moving device includes a stepper motor and a moving platform 400; the stepper motor is used for driving the mobile platform 400 to move; the detector is disposed on the mobile platform 400.

It should be noted that, fig. 3 is a schematic diagram of a portion of a moving device according to an embodiment of the present invention, where the moving device includes a moving platform 400 and a stepper motor (not shown in the drawings), and in the embodiment of the present invention, the displacement of the detector can be controlled by adjusting the step length of the stepper motor, so as to avoid the problem of inaccurate centering caused by fixed moving distance.

Referring to fig. 2 and 4, fig. 4 is a schematic block diagram of a centering method of a laser particle analyzer according to an embodiment of the present invention, which is applied to the laser particle analyzer according to the embodiment of the above aspect, the centering method includes;

step S100, a laser device emits a detection laser beam to a detector;

step S200, acquiring the light energy detected by each first detection zone 100 and each first detection zone 200, and determining the first detection zone 100 or the first detection zone 200 which is the closest to the center point 300 of the detector and has the light energy greater than a first threshold value as a target detection zone;

step S300, determining the moving direction of the detector according to the first mark or the second mark marked on the target detection belt, and moving the detector towards the moving direction through the moving device until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection belts and all the second detection belts;

in step S400, the moving device moves the detector up or down along the vertical direction until the light energy detected by the center point of the detector is the maximum value in the vertical direction, and the centering is completed.

In step S100 to step S200, when the detector detects the light energy of the light spot, it is necessary to determine the detection band in which the maximum light energy is detected, so as to determine the center position of the light spot. Further, in steps S300 to S400, the moving direction of the detector is determined according to the mark of the target detection zone where the light spot is located, the position of the detector is repeatedly adjusted until the light energy detected by the center point 300 of the detector is the maximum, at this time, the light spot and the center point 300 of the detector can be considered to be on the same straight line in the vertical direction at the same time, and finally, the light spot is completely dropped into the center point 300 of the detector after the alignment in the vertical direction in step S400, so that the alignment is completed. It should be noted that, the centering method of step S100 to step S400 is based on the laser particle analyzer provided in the embodiments of the foregoing aspect, and the centering direction can be quickly determined by virtue of the advantage that the first detection zone 100 and the first detection zone 200 on the laser particle analyzer can be used for distinguishing the directions, and the centering efficiency of the laser particle analyzer is improved by virtue of the precise movement of the moving device.

In some embodiments of the present invention, the step of acquiring the light energy detected by each first detection zone 100 and each first detection zone 200, determining the first detection zone 100 or first detection zone 200 having the light energy greater than the first threshold and closest to the detector center point 300 as the target detection zone, includes:

in step S210, if the light energy detected by each of the first detecting bands 100 and each of the first detecting bands 200 is smaller than the first threshold, the detector is moved up or down in the vertical direction by the moving device until the light energy detected by the plurality of first detecting bands 100 or the plurality of first detecting bands 200 is larger than the first threshold.

It should be noted that, when the laser device sends the detection laser beam to the detector to form a light spot, if the light energy detected by each first detection band 100 and each first detection band 200 is smaller than the first threshold value during the first detection, the light spot is considered not to be located on any one of the first detection bands 100 or 200 provided in the embodiment of the present invention in the vertical direction, so that coarse centering needs to be performed by moving the detector upwards or downwards, and the purpose of coarse centering is to make the light spot move into the range of the detector, so as to prepare for the left-right adjustment in the next fine centering.

In some embodiments of the present invention, if the light energy detected by each of the first detecting bands 100 and each of the first detecting bands 200 is less than the first threshold value, the step of moving the detector up or down in the vertical direction by the moving device until the light energy detected by the plurality of first detecting bands 100 or the plurality of first detecting bands 200 is greater than the first threshold value includes:

step S211, the moving device moves the detector upwards or downwards along the vertical direction according to a preset step length;

in step S212, if the detected light energy of each first detection zone 100 and each second detection zone 200 is still smaller than the first threshold after the detector moves for the preset number of times, the preset step length is modified, and the step of moving the detector up or down in the vertical direction by the moving device according to the preset step length is returned until there is a first detection zone 100 or a second detection zone 200 with the detected light energy greater than the first threshold.

It should be noted that, step S211 to step S212 are specific steps in the coarse centering, after the coarse centering is started, the light spot is controlled to move up or down once, then the light energy of all the first detection bands 100 and 200 is read, and if any detection band is detected that the received light energy is greater than a certain threshold, the fine centering can be entered to perform adjustment in the horizontal left-right direction. According to the step length of the stepping motor, if no ring number exists in the upper n steps or the lower n steps, changing the step length of the stepping motor, and moving upwards or downwards for 2n steps, and if no ring number exists in the optical energy, moving upwards or downwards for 4n steps, and sequentially performing the steps until the light spot falls into the range of the detector after the up-down movement.

In some embodiments of the invention, the first detection zone is disposed to the left of the center point of the detector and the second detection zone is disposed to the right of the center point of the detector; the first marks are odd marks which are sequentially increased from the direction close to the center point of the detector to the direction far from the center point of the detector, and the second marks are even marks which are sequentially increased from the direction close to the center point of the detector to the direction far from the center point of the detector; determining a moving direction of the detector according to a position of the target detection zone, and moving the detector toward the moving direction by a moving device until the light energy detected by the detector center point 300 is a maximum value in the moving direction and in a direction opposite to the moving direction, including:

step S310, judging the moving direction of the detector according to the odd number mark or the even number mark marked on the target detection band;

step S320, if the target detection zone is marked with an odd number, the moving device moves the detector leftwards until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection zone and the second detection zone;

in step S330, or if the target detection zone is marked with an even number, the moving device moves the detector rightward until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection zone and the second detection zone.

In step S310 to step S330, the control module of the tester obtaining the laser particle analyzer may determine the position of the light spot according to the mark marked by the target detection zone, obtain a specific moving direction, and move the detector according to the moving direction. Further, the method for confirming that the light energy detected by the center point of the detector is greater than the light energy detected by all the first detecting strip and the second detecting strip, besides the method for sequentially confirming through sequential measurement and comparison, further includes detecting the light energy detected by the first detecting strip 100 and the first detecting strip 200 closest to each other, when the light energy detected by the first detecting strip 100 and the first detecting strip 200 closest to each other is the same, the light energy on the left side and the right side of the center point 300 of the detector can be considered to be symmetrical, and the light spot and the center point 300 of the detector are simultaneously on the same straight line in the vertical direction. It will be appreciated that excessive movement of the detector may occur when the detector is moved by the moving means, for example, the spot moves from the left to the right of the detector center point 300, at which time the target detection zone needs to be redetermined according to the amount of light energy of the current detection zone and moved in the direction of movement of the new target detection zone (i.e., in the opposite direction to the original direction of movement). Further, it can be understood that, according to the above embodiment, the aperture of the center point 300 of the detector is larger than the diameter of the light spot, so when the light spot moves to the center point 300 of the detector, if the center of the light spot does not coincide with the geometric center of the center point 300 of the detector, the light energy detected by the first detecting strip 100 and the first detecting strip 200 closest to each other will have a difference, and therefore, according to the embodiment of the present invention, a certain error may be set according to the aperture size of the center point 300 of the detector and the diameter size of the light spot, and the difference between the light energy detected by the first detecting strip 100 and the first detecting strip 200 closest to each other is within the above error range, that is, the light energy on the left side and the right side of the center point 300 of the detector may be considered to be symmetrical, and the light spot and the center point 300 of the detector are simultaneously on the same straight line in the vertical direction. Further, since the center point 300 of the detector is not a point in the geometric sense, the light spot and the center point 300 of the detector are simultaneously on the same straight line in the vertical direction, and in the actual centering process, only the light spot needs to fall into a rectangular area with the aperture of the detector as the width in the horizontal direction and the length in the vertical direction.

In some embodiments of the present invention, the moving device moves the detector upward or downward along the vertical direction until the light energy detected by the center point of the detector is the maximum value in the vertical direction, and the step of centering is completed, including:

step S410, the moving device moves the detector upwards or downwards along the vertical direction, and records the light energy detected by the center point 300 of the detector after the movement;

step S420, after each movement, comparing the light energy detected by the center point 300 of the detector recorded before and after the movement;

in step S430, if the value of the light energy detected by the detector center point 300 before is smaller than the value of the light energy detected by the detector center point 300 after, the moving device continues to move the detector in the same direction, or if the value of the light energy detected by the detector center point 300 before is greater than the value of the light energy detected by the detector center point 300 after, the moving device moves the detector in the opposite direction until the light energy detected by the detector center point 300 is the maximum value in the vertical direction, and the centering is completed.

It should be noted that, in the steps S410 to S430, the purpose of the fine centering step is to move the light spot onto the detection band only in the difference from the coarse centering step, so that only any detection band is required to detect the light energy, and the fine centering is required to ensure that the light spot falls within the range of the center point 300 of the detector, so that the magnitudes of the light energy detected by the center point 300 of the detector after the previous movement and the light energy detected by the center point 300 after the subsequent movement need to be continuously compared to ensure that the light spot falls within the center point. It can be appreciated that the embodiment of the present invention may also change the distance of upward or downward movement by adjusting the step size of the stepper motor in the embodiment of the above aspect, for example, adjusting the step size of the stepper motor, so that the position of the light spot displaced each time relative to the detector is smaller than the aperture size of the detector center point 300, and the detector center point 300 is prevented from being missed during the movement of the detector.

According to some embodiments of the invention, the laser particle analyzer further comprises a control module for controlling the movement of the moving device and the laser device to emit laser light; the control module is also connected with the detector, and the light energy detected by the detection belt is uploaded to the upper computer through the control module for analysis by test personnel.

Several embodiments of the present invention are given below in accordance with the above-described aspects of the embodiments.

Referring to fig. 2, according to some embodiments of the present invention, the first marks of the first detector of the laser particle analyzer are odd numbers of different sizes, the second marks of the second detector are even numbers of different sizes, all odd numbered detection zones are disposed to the left of the detector center point 300, and all even numbered detection zones are disposed to the right of the detector center point 300; the number sizes of the odd numbered detection bands are sequentially increased from the position close to the center point 300 of the detector to the position far from the center point 300 of the detector, and the number sizes of the even numbered detection bands are sequentially increased from the position close to the center point 300 of the detector to the position far from the center point 300 of the detector; the first direction of the odd numbered detection zones is opposite to the increasing direction of the first marked marks, i.e. from the direction away from the detector to the direction closer to the detector center point 300; the second direction of the even numbered detection zones is opposite to the increasing direction of the second marked marks, i.e. from the direction away from the detector to the direction closer to the detector center point 300; the odd numbered detection bands and the even numbered detection bands are distributed in a fan shape; the areas of all odd numbered detection zones are sequentially increased from the direction approaching the center point 300 of the detector to the direction separating from the center point 300 of the detector; the areas of all even numbered detection zones are sequentially increased from the direction approaching the center point 300 of the detector to the direction separating from the center point 300 of the detector; the spacing between each odd numbered detector strip increases from a direction closer to the detector center point 300 to a direction farther from the detector center point 300; the spacing between each even numbered detector strip increases in sequence from a direction closer to the detector center point 300 to a direction farther from the detector center point 300.

Referring to fig. 5, fig. 5 is a complete flow chart of a method for centering a laser particle size analyzer according to an embodiment of the present invention, where a control module controls a laser device to emit a detection laser beam to a detector; firstly, roughly centering the detector, controlling the mobile device to change the position of the detector by the control module, and judging whether the light spot falls on any detection band or not according to the light energy detected by the detection band; after the light spot falls on any detection zone, a detection zone with the largest light energy is acquired, for example, the detection zone with the largest light energy of odd numbers is detected, so that the light spot can be confirmed to fall on the left side of the detection zone, and the detector can be immediately confirmed to need to be moved leftwards, so that the light spot falls into the center point 300 of the detector; if detecting the detection band with the maximum even number of light energy, the detector needs to be moved to the right; the light energy detected by the nearest odd numbered detection zone and the nearest even numbered detection zone are within the same error range, and the light spot can be considered to be in line with the detector center point 300; and then fine centering is carried out, and the whole centering process is completed.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present invention.

Claims (10)

1. A laser particle sizer, comprising:

the detector comprises a detector center point, a plurality of first detection bands distributed at intervals and a plurality of second detection bands distributed at intervals; the plurality of first detection bands and the plurality of second detection bands are symmetrically distributed on the left side and the right side of the center point of the detector; each first detection zone is marked with a first mark; each second detection zone is marked with a second mark;

a laser device for emitting a detection laser beam to the detector;

and the moving device is used for moving the detector.

2. The laser particle sizer of claim 1, wherein the first detection zone is disposed to the left of the detector center point and the second detection zone is disposed to the right of the detector center point; the first marks are odd marks sequentially increasing from a direction close to the center point of the detector to a direction far from the center point of the detector, and the second marks are even marks sequentially increasing from the direction close to the center point of the detector to the direction far from the center point of the detector.

3. The laser particle sizer of claim 1, wherein the first detection zone and the second detection zone comprise a matrix of a plurality of photodiodes.

4. The laser particle sizer of claim 1, wherein the first detection zone and the second detection zone are fan-shaped in distribution; the areas of all the first detection zones are sequentially increased from the direction from the center point of the detector to the direction away from the center point of the detector; the areas of all the second detection zones are sequentially increased from the direction from the center point of the detector to the direction away from the center point of the detector; the distance between each two first detection bands increases from the direction close to the center point of the detector to the direction far from the center point of the detector; the distance between each two second detection bands increases from the direction approaching the center point of the detector to the direction separating from the center point of the detector.

5. The laser particle sizer of claim 1, wherein the moving means comprises a stepper motor and a moving platform; the stepping motor is used for driving the mobile platform to move; the detector is arranged on the mobile platform.

6. A method of centering a laser particle sizer, characterized in that it is applied to the laser particle sizer of any one of claims 1 to 5, the centering method comprising;

the laser device emits a detection laser beam to the detector;

acquiring light energy detected by each first detection zone and each second detection zone, and determining the first detection zone or the second detection zone which is larger than a first threshold value and closest to the center point of the detector as a target detection zone;

determining the moving direction of the detector according to the first mark or the second mark marked on the target detection belt, and moving the detector towards the moving direction through a moving device until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection belts and all the second detection belts;

and the moving device moves the detector upwards or downwards along the vertical direction until the light energy detected by the center point of the detector is the maximum value in the vertical direction, so that centering is completed.

7. The method of centering a laser particle sizer of claim 6, wherein the step of obtaining the optical energy detected by each first detection zone and each second detection zone, determining the first detection zone or the second detection zone that is closest to the center point of the detector and that is greater than a first threshold value, as a target detection zone, further comprises:

if the light energy detected by each first detection band and each second detection band is smaller than the first threshold value, the detector is moved upwards or downwards along the vertical direction by the moving device until the first detection band or the second detection band with the detected light energy larger than the first threshold value exists.

8. The method of centering a laser particle sizer of claim 7, wherein if the optical energy detected by each of the first detection zone and each of the second detection zone is less than the first threshold, moving the detector vertically upward or downward by the moving means until the optical energy detected by any of the first detection zone or the second detection zone is greater than the first threshold, comprising:

the moving device moves the detector upwards or downwards along the vertical direction according to a preset step length;

and if the light energy detected by each first detection band and each second detection band is still smaller than a first threshold value after the detector moves for a preset number of times, modifying the preset step length, and returning to the step of moving the detector upwards or downwards along the vertical direction by the moving device according to the preset step length until the first detection band or the second detection band with the detected light energy larger than the first threshold value exists.

9. The method of claim 6, wherein the first detection zone is disposed to the left of the center point of the detector and the second detection zone is disposed to the right of the center point of the detector; the first marks are odd marks which are sequentially increased from the direction close to the center point of the detector to the direction far from the center point of the detector, and the second marks are even marks which are sequentially increased from the direction close to the center point of the detector to the direction far from the center point of the detector; the step of determining the moving direction of the detector according to the first mark or the second mark marked on the target detection belt, and moving the detector towards the moving direction by a moving device until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection belt and all the second detection belt comprises the following steps:

judging the moving direction of the detector according to the odd number mark or the even number mark marked on the target detection belt;

if the target detection zone is marked with the odd number, the moving device moves the detector leftwards until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection zone and the second detection zone;

or if the even number marks are marked on the target detection zone, the moving device moves the detector rightwards until the light energy detected by the center point of the detector is greater than the light energy detected by all the first detection zone and the second detection zone.

10. The method of centering a laser particle sizer of claim 6, wherein the moving means moves the detector upward or downward in a vertical direction until the light energy detected by the detector center point is a maximum in the vertical direction, the step of centering being completed, comprising:

the moving device moves the detector upwards or downwards along the vertical direction and records the light energy detected by the center point of the detector after the movement;

after each movement, comparing the light energy detected by the center point of the detector twice recorded before and after the movement;

if the value of the light energy detected by the detector center point in the last time is smaller than the value of the light energy detected by the detector center point in the last time, the moving device continues to move the detector in the same direction, or if the value of the light energy detected by the detector center point in the last time is larger than the value of the light energy detected by the detector center point in the last time, the moving device moves the detector in the opposite direction until the light energy detected by the detector center point is the maximum value in the vertical direction, and centering is completed.