KR20190129214A - Focus measurement apparatus and focus measurement method using the same - Google Patents

Abstract

The present invention relates to a focus measuring device. An embodiment of the present invention is a device for confirming a focus of a light beam, wherein proposed is the focus measuring device comprising: a light transmitting part having a through-hole for passing the light beam; a sensor part disposed at a predetermined interval from the light transmitting part and detecting the light beam passing through the through-hole of the light transmitting part; a moving part which moves the light transmitting part and the sensor unit such that the light beam passes through the through-hole of the light transmitting part so as to be sensed by the sensor part; and a focus confirming part moving the moving part such that the light beam detected by the sensor part passes through a center of the through-hole of the light transmitting part, storing an intensity of the light beam measured by the sensor part, and determining a point in which the intensity of the detected light beam is a maximum as a focus while changing a height of the sensor part.

Description

Focus measurement apparatus and focus measurement method using the same

The present invention relates to a device for measuring the focus of a light beam such as a laser and a focus measuring method using the same.

When processing using a light beam such as a laser, it is desirable to accurately focus on the processing surface. With the correct focus on the machining surface, machining can be carried out accurately without wasting energy.

In general, information on the focus of a particular light beam processing equipment is provided by the manufacturer. However, this information is a guideline and may be somewhat different from the information provided by the manufacturer on the actual manufacturing site.

As such, the technology presented in Korean Patent No. 10-1449851 is disclosed as a prior art for finding the actual focus. The prior art uses a jig having an inclined and graduated surface, so that the laser is irradiated to the inclined surface to determine the position of the focus by actual combustion.

However, even when the focus is not true, combustion may occur, and in this case, there is a difficulty in determining the focus according to the degree of combustion. In addition, there is a problem in terms of utilization of data since a new jig is required every time the focus is measured and the data of the focus measuring process cannot be utilized.

Republic of Korea Patent No. 10-1449851 (2014.10.02)

The present invention is to measure the intensity of the light beam passing through the through hole of the light transmitting portion and to focus by using the data of the focus measurement process to prevent damage to the sensor due to the light beam and to accurately detect the light beam on the sensor In addition, the present invention provides a focus measuring apparatus capable of accurately checking focus.

Other detailed objects of the present invention will be apparently understood and understood by those skilled in the art through the following detailed description.

In order to solve the above problems, the present invention is an embodiment, as a device for checking the focus of the light beam, a light transmitting portion formed with a through hole for passing the light beam, disposed at a predetermined distance from the light transmitting portion and the through hole of the light transmitting portion A sensor unit for detecting the light beam passing through, the moving unit for moving the light transmitting unit and the sensor unit so that the light beam is passed through the light through the light transmitting part to be detected by the sensor unit and the light beam detected by the sensor unit penetrates the light transmitting unit And a focus confirming unit which moves the moving unit to pass through the center of the hole, stores the intensity of the light beam measured by the sensor unit, and determines the point where the intensity of the detected light beam is maximum while changing the height of the sensor unit as the focus. Present the focus measuring device.

Here, the light transmitting portion may be made of a metal plate having a predetermined thickness and a through hole may be formed in the center of the metal plate.

In addition, the light transmitting unit and the sensor unit may be coupled to both ends of the plurality of gap adjusting members, respectively, at a predetermined interval.

In addition, the moving unit is coupled to the sensor unit and the plane of the sensor unit by moving the light transmitting part and the sensor unit connected to the sensor unit and the gap through the gap adjusting member while moving the light beam through the through hole of the light transmitting portion It can be detected by the sensor unit.

On the other hand, the focus confirming unit, a movement unit designation module for designating a measurement interval that can be moved at a time, the movement unit designates a movement path to measure the intensity of the light beam while moving the light transmitting portion in a spiral according to the measurement interval specified by the movement unit designation module A moving designation module for dividing the intensity of the light beam detected by the sensor unit into a grid in accordance with the movement of the moving unit according to the measurement interval, and converting the image into an image; the position of the sensor unit or the position of the light beam up and down While moving the light beam intensity storage module for storing the intensity of the light beam measured by the sensor and converted in the image conversion module and the information stored in the light beam intensity storage module to compare the data having the largest intensity in a certain area of the focus data It may include a focus determination module to determine to.

Meanwhile, in order to solve the above problem, the present invention is an embodiment, a method for checking the focus of a light beam using the above-described focus measuring device, the first step of irradiating the light beam to pass through the through-hole formed in the light transmitting portion, through A second step of measuring the intensity of the light beam passing through the hole and positioning the point where the intensity of the light beam is the largest so as to be the center of the through hole; A third step of measuring the intensity of the light beam while moving, a fourth step of measuring the intensity of the light beam while moving the height of the sensor portion or the height of the light beam up and down, and a height at which the intensity of the light beam in a predetermined region is maximum as the height of the focus A focus measuring method including a fifth step of determining is provided.

Here, the second step, the step of measuring the intensity of the light beam while moving the light transmitting portion at regular intervals in a spiral path around the center of the through-hole, the intensity of the light beam measured while the light transmitting portion is moved the light transmitting portion The method may include storing the light by matching the position with the light source and moving the light transmitting part so that the center of the through hole is positioned at the position having the greatest intensity among the stored light beams.

According to the exemplary embodiment of the present invention, the light beam may be accurately detected by the sensor while preventing the damage of the sensor due to the light beam, and the focus may be accurately confirmed by comparing the data of the focus measuring process.

Other effects of the present invention will be apparent to and understood by those skilled in the art through the following detailed description or in the course of carrying out the present invention.

1 is a perspective view of a focus measuring device according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a focus confirmation unit employed in the focus measuring apparatus shown in FIG. 1. FIG.
3 is a view illustrating a process of measuring the intensity of a light beam while moving a light transmitting unit using the focus measuring apparatus shown in FIG.
4 is a view showing that the intensity of the light beam measured according to the process of FIG. 3 is converted into an image by matching the position of the light transmitting part.
FIG. 5 is a diagram showing an example of a screen for operating the focus measuring device shown in FIG. 1; FIG.
6 is a flowchart illustrating a method of confirming focus using the focus measuring apparatus shown in FIG. 1.
FIG. 7 is a view illustrating a process of moving a light transmitting part such that a light beam passes through a center of a through hole in the focus measuring apparatus shown in FIG. 1.
FIG. 8 is a diagram illustrating an image obtained by converting an intensity of a light beam measured in a process of checking focus using the focus measuring apparatus shown in FIG. 1. FIG.
9 is a view showing a process of finding a focus by measuring the intensity of the light beam while changing the height of the sensor unit in the focus measuring apparatus shown in FIG.

The above-described features and effects of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, and thus, those skilled in the art to which the present invention pertains may easily implement the technical idea of the present invention. Could be. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Hereinafter, a focus measuring apparatus and a focus measuring method using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, the same reference numerals are used to designate similar components in different embodiments, and the description thereof is replaced with the first description. In addition, components shown for convenience of description may be exaggeratedly displayed.

The focus measuring apparatus 100 according to the exemplary embodiment of the present invention is a device for checking the focus of a light beam, and includes a light transmitting unit 1, a sensor unit 2, a moving unit 3, and a focus confirming unit 4. do.

The light transmitting portion 1 is formed with a through hole 11 through which the light beam passes, and the sensor portion 2 is disposed at a predetermined distance from the light transmitting portion 1 and passes through the through hole 11 of the light transmitting portion 1. A light beam is detected. One through hole 11 may be formed, and only the light beam passing through the through hole 11 is detected by the sensor unit 2.

Meanwhile, the moving part 3 moves the light transmitting part 1 and the sensor part 2 so that the light beam passes through the through hole 11 of the light transmitting part 1 and is sensed by the sensor part 2. The moving part 3 may move the light transmitting part 1 and the sensor part 2, respectively, or may move one of the light transmitting part 1 and the sensor part 2 in an integrated form.

The focus checker 4 moves the moving part 3 so that the light beam sensed by the sensor part 2 passes through the center of the through hole 11 of the light transmitting part 1, and is measured by the sensor part 2. The intensity of the light beam is stored, and the point where the intensity of the detected light beam is maximum is determined as the focal point while changing the height of the sensor unit.

Hereinafter, the structure of each part is demonstrated in detail with reference to drawings.

1 is a perspective view of a focus measuring apparatus according to an exemplary embodiment of the present invention, and FIG. 2 is a block diagram illustrating a focus check unit employed in the focus measuring apparatus illustrated in FIG. 1.

The light transmitting part 1 functions to selectively pass the light beam, and is formed of a copper plate having a predetermined thickness and a through hole 11 is formed in the center of the copper plate.

Since the light beam has a lot of energy, there is a risk of damaging the sensor unit 2. Therefore, if the through-hole 11 is formed at a position corresponding to the sensor 21 of the sensor unit 2 in an object of the material that the light beam does not transmit, the sensor unit while preventing the light beam from touching other parts of the sensor unit 2 The light beam can reach only the sensor 21 of (2).

In the above description, the material of the light transmitting part 1 is described as a copper plate, but other metal plates or other materials may be used to prevent the light beam from being transmitted and damaged. By this light transmitting portion, the light beam can be safely guided to the sensor portion.

The sensor unit 2 is a portion in which the light beam passing through the through hole 11 of the light transmitting unit 1 is sensed, and may be configured using a general light beam detection sensor. An example of this may be AHW-50-D25 manufactured by Laser Point.

The sensor 21 may output a current value corresponding to the intensity of the light beam according to the intensity, and receive the value to display the intensity of the light beam on the screen.

Meanwhile, the light transmitting unit 1 and the sensor unit 2 may be coupled to both ends of the plurality of gap adjusting members 20 and disposed at predetermined intervals. By integrating the light transmitting portion 1 and the sensor portion 2 in this way, the light transmitting portion 1 and the sensor portion 2 can be easily moved while maintaining the corresponding positions.

The moving unit 3 has a function of moving the sensor unit 2 and the light projecting unit 1, and includes a driver 31 to allow two-dimensional plane movement or three-dimensional space movement. Can be. In the case where the plane movement is possible, the height movement may use a separate driving mechanism, and the separate driving mechanism may move a work table (not shown) on which the focus measuring apparatus 100 is placed.

Referring to the drawings, in this embodiment, the moving part 3 is coupled to the sensor part 2 and the light transmitting part connected through the sensor part 2 and the gap adjusting member 20 by moving the sensor part 2 in a plane. 1) is moved together with the sensor unit 2.

Therefore, the position of the sensor unit 2 and the light projecting unit 1 is kept constant and the light beam passes through the through hole 11 of the light projecting unit 1 by moving the sensor unit 2 so that the sensor unit 2 is moved. You can move the position to be detected.

The focus confirming unit 4 analyzes the intensity of the light beam detected by the sensor unit 2 and determines the position of the focus while moving the moving unit 3. The movement unit specifying module 41 and the movement specifying module 42 ), An image conversion module 43, a light beam intensity storage module 44, and a focus determination module 45.

The movement unit designation module 41 designates a measurement interval in which the moving part can move at one time when measuring the intensity of the light beam. The focus check unit 4 operates the moving unit 3 to change the position of the through hole 11 of the light transmitting unit 1 while passing through the through hole 11 to measure the light beam intensity irradiated to the sensor unit 2. The mobile unit designation module 41 specifies the measurement interval at this time. The measurement interval may be, for example, 3 micrometers. In this case, the light beam intensity measured by the sensor unit 2 is analyzed by passing through the through-hole 11 while moving by 3 micrometers.

The movement designation module 42 designates a movement path so as to measure the intensity of the light beam while helically moving the light projector 1 according to the measurement interval designated by the movement unit designation module 41. As shown in FIG. 3, the movement path is spirally moved from the center to the outside along each of the checkerboard cells formed according to the measurement intervals.

When the light transmission part 1 moves helically along the movement path designated by the movement designation module 42, the through hole 11 of the light transmission part 1 moves helically from the point where the through hole was initially located. According to the position of the through-hole 11 to transmit the entire light beam or a part of the light beam intensity of the light beam detected by the sensor unit 2 is changed.

As such, the intensity of the light beam measured according to the position of the through hole 11 is converted by the image conversion module 43 and stored in the light beam intensity storage module 44. As such, the intensity of the light beam corresponding to the position of the through hole 11 can be known by matching and storing the intensity of the light beam measured according to the position of the through hole 11 and whether the light beam passes through the center of the through hole 11. It can also be known. This will be described later.

The image conversion module 43 converts the intensity of the light beam detected by the sensor unit 2 into a grid shape according to the measurement interval according to the movement of the moving unit 3 according to the measurement interval and converts the image into an image. As shown in FIG. 4, the highest intensity of the light beam is darkest (red) as shown in FIG. 4, and as the intensity of the light beam decreases, the converted image is distributed from medium (orange) to light (yellow).

The light beam intensity storage module 44 stores the intensity of the light beam measured by the sensor unit 2 while moving the position of the sensor unit 2 or the position of the light beam up and down. In this case, the intensity of the light beam stored is the intensity of the light beam corresponding to the position of the through hole 11, which may be converted into an image.

The intensity of the light beam converted into an image allows for faster confirmation of the focus by analysis of the vision system. It also has an easy-to-use form for future analysis.

Since the focus of the light beam is expected to be the greatest, the focus can be determined by storing the measured light beam intensities while comparing the positions of the light beams. The movement of the position of the sensor unit 2 may be performed by the moving unit 3, and the movement of the position of the light beam may be performed by adjusting a scanner built in the light beam irradiation apparatus 30.

The focus determination module 45 compares the information stored in the light beam intensity storage module 44 and determines the data having the greatest intensity as the data of the focus. Since the light beam intensity storage module 44 stores the intensity of the light beam corresponding to various conditions, the data having the largest value corresponds to the data of the focus.

On the other hand, the comparison object may be the intensity of the light beam included in a predetermined region of the stored information as shown in FIG. When the area to be compared is designated as 10 micrometers in width and width in the above description, since one side of the grating is 3 micrometers, the area of the center 3x3 can be compared and the intensity of the light beam in this area is the largest. Can be the focus.

In this way, the accuracy can be increased by measuring the intensity of the light beam in the predetermined region. The criterion for selecting a certain region may be input by an operator.

5 is a diagram illustrating an example of a screen for operating the focus measuring apparatus shown in FIG. 1.

Referring to the drawings, the movement of the moving unit, the measurement instruction, the communication state, the size and shape of the focus can be checked through the monitoring screen.

In this screen, the operator can operate the moving unit 3 to move on the horizontal plane by using the XY MOVE operation button and move the moving unit 3 up and down or move the work table up and down using the Z MOVE operation button. You can. You can also enter the measurement interval.

In addition, the intensity of the light beam detected by the sensor unit 2 in the current state can be measured by using the measurement instruction button. The intensity of the light beam measured in this way is displayed on the data screen to check the state and size of the focus. Meanwhile, as the moving part moves helically according to the measurement interval, the intensity of the light beam according to each movement may be automatically measured.

On the other hand, it is possible to set the communication state and communication connection for setting various operations and set values for the light beam focus measurement.

Hereinafter, a method of confirming focus using a focus measuring apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 6 is a flowchart illustrating a method of checking focus using the focus measuring apparatus illustrated in FIG. 1, and FIG. 7 is a view illustrating an image measured in the process of confirming focus using the focus measuring apparatus illustrated in FIG. 1. to be.

Focus measuring method according to an embodiment of the present invention, a method for confirming the focus, the first step of irradiating the light beam to the sensor 21 through the through-hole 11, the irradiated light beam of the through-hole 11 A second step of positioning the beam to pass through the center, a third step of measuring the intensity of the light beam along the path, a fourth step of measuring the light beam while moving the height, and a fifth step of determining the point where the intensity of the light beam is maximum as the focal point It includes.

In the first step, the light beam is irradiated to pass through the through hole 11 formed in the non-transmissive body. The non-transmissive body corresponds to the light transmitting part 1 in the above-described focus measuring device 100 and irradiates a light beam to pass through the through hole 11 formed in the light transmitting part 1 (S10).

When the first light beam is irradiated, the light beam may pass through the center portion of the through hole 11, but in some cases, there may be a slight difference as shown in FIG. 7A. Therefore, it is necessary to adjust the light beam B to pass through the central portion of the through hole 11.

To this end, in the second step, the intensity of the light beam passing through the through hole 11 is measured and positioned so that the point where the intensity of the light beam is largest is the center of the through hole 11 (S20).

Whether the light beam B passes through the central portion of the through hole 11 can be confirmed by measuring the intensity of the light beam while moving the sensor unit 2 in a spiral manner.

That is, assuming that the light beam B has passed through the upper left side of the through hole 11 as shown in FIG. 7A at the measurement position of the current sensor unit 2, referring to the drawing, the movement path of the sensor unit 2 is determined. The point corresponding to (5, 5) becomes the center point C of the through hole on the checkerboard coordinates shown, and the light beam B passes through the point corresponding to (4, 3).

At this time, when the sensor unit 2 is moved in a spiral at a predetermined interval using the moving unit 3, the through hole 11 of the light transmitting unit 1 connected to the sensor unit 2 is also moved in a spiral at regular intervals. The center point C of the through hole 11 also moves helically. As the through hole 11 moves, the intensity of the light beam according to each coordinate is matched and stored as an image.

FIG. 7B is a view showing when the center point of the through hole 11 moves to (4, 3) by the movement of the moving part 3. At this time, since the light beam B passes through the center of the through hole, the intensity of the light beam B becomes maximum. In addition, when the through-hole 11 is located near this (4, 3) coordinate, the intensity of the light beam is large.

FIG. 7C is a diagram showing a time when the center point of the through hole 11 moves to (7, 8) by the movement of the moving part 3. In this case, since the light beam B does not pass through the through hole, the intensity of the light beam B is minimized. In addition, when the through-holes are located near the (7, 8) coordinates, the intensity of the light beam is substantially small.

In this way, when the entire light beam B passes through the through hole 11, it is imaged and displayed in dark (red), and when a part of the light beam B passes through the through hole, it is neutral (orange). When the light beam does not pass through the through-hole, the image is displayed in pale (yellow) and displayed according to the position of the through-hole (or the light-transmitting part), as shown in FIG. 8 (a). This means that the light beam B passes through the upper left side of the through hole 11 when viewed from the point where the through hole 11 is located, which corresponds to 7 (a) showing the actual position of the light beam passing through.

Therefore, it is necessary to move the center point C of the through hole 11 to the upper left side, and at this time, the center point C of the through hole is moved to the (4, 3) coordinate where the intensity of the largest light beam is measured. Accordingly, the light beam B may pass through the center of the through hole 11.

Next, in the third step, the intensity of the light beam is measured while moving the light-transmitting unit 1 at a predetermined interval around the center of the through-hole 11 in a spiral path (S30).

As shown in FIG. 3, the points to measure the intensity of the light beam are partitioned in a checkerboard shape according to the designation of the measurement interval. The intensity of the light beam at each point is measured while traveling through the light transmitting portion 1 and the sensor portion 2 in a spiral path along the divided unit region. Accordingly, the intensity of the light beam can be measured at a plurality of points depending on the positions of the light transmitting part 1 and the sensor part 2. In this case, the measured intensity of the light beam may be converted into an image for each point and then matched and stored.

The intensity of the light beam thus measured is shown in FIGS. 4 and 8 (b) to 8 (d). The intensity of the light beam displayed in each cell of the lattice shape indicates the intensity of the light beam when the center of the through hole 11 is located at the position of each cell, and the light beam is formed at the center of the through hole 11 in the above-described second step. Since the state through which the through-hole 11 has a center point (C) is located in the center of the cell has a form of the light beam has the largest intensity.

Next, in step 4, the intensity of the light beam is measured according to the above-described process while the height of the sensor unit or the height of the light beam is moved up and down (S40).

In general, information on the focus of a particular light beam processing equipment is provided by the manufacturer. However, this information is a guideline and may be somewhat different from the information provided by the manufacturer on the actual manufacturing site.

Therefore, even if the intensity of the light beam measured in the above-described third step is performed based on the focus information of the manufacturer, it is difficult to determine this as the focus. Therefore, while moving the height of the light emitting unit 1 and the sensor 21 or moving the height of the light beam is moved up and down, it is necessary to find a point that is more in focus or verify whether the above conditions actually correspond to the focus.

Therefore, while increasing or decreasing the height by a predetermined unit, it is repeated to measure the intensity of the light beam in a spiral path as in the third step described above.

9 is a conceptual diagram illustrating a process of finding a focus by measuring an intensity of a light beam while changing a height of a sensor unit in a focus measuring apparatus.

9 (a) to 9 (c), the focus is the same, and FIG. 9 (a) shows that the sensor is located at the focus position, and FIG. 9 (b) is higher than the focus position. It shows that the sensor is located at the position, Figure 9 (c) shows that the sensor is located at a lower position than the focus position.

Next, in the fifth step, the height of the maximum intensity of the light beam in the predetermined region is determined as the height of the focal point (S50).

The data collected by repeated measurements are analyzed to analyze the intensity of the light beam in a certain area according to the height or condition and determine the height or condition at which the intensity of the analyzed light beam is maximum as the condition of focus. As a method of analyzing the intensity of the light beam in a certain region, for example, a method obtained by adding up the intensity of the light beam in a predetermined region according to the height of the sensor unit and comparing the values may be used.

Referring to FIG. 8, the largest intensity of the light beam is the case of FIG. 8 (b), which corresponds to the case of FIG. 9 (a) when viewed from the position of the sensor unit. The height of such a sensor part can be determined as a condition of focus. Accordingly, it is possible to know the exact position of the focus and to obtain focus-related data. On the other hand, even at the same height, it is also possible to derive the optimum conditions for the light beam by measuring at various angles while changing the shape or output of the light beam.

It is also possible to store the conditions of the light beam irradiator or the relative position of the light beam irradiator with the focal point and repeat the whole process to check the position of the focal point by the average value.

On the other hand, by arranging the work table according to the identified focus position, the work can be performed in the focus area even in the actual 3D printing work.

Although the above description of the present invention has been described with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described later. It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

1: light transmitting portion 11: through hole
2 sensor unit 21 sensor
3: moving part 31: driver
4: Focus check unit
41: moving unit designation module 42: moving designation module 43: image conversion module
44: light beam intensity storage module 45: focus determination module
B: light beam C: center point
10: base 20: gap adjusting member 30: light beam irradiation device
100: focus measuring device

Claims (7)

A device for checking the focus of a light beam,
A light transmitting part having a through hole for passing a light beam,
A sensor unit disposed at a predetermined distance from the light transmitting unit and detecting a light beam passing through a through hole of the light transmitting unit;
A moving part which moves the light transmitting part and the sensor part so that the light beam passes through the light transmitting part and is sensed by the sensor part;
The moving part is moved so that the light beam sensed by the sensor part passes through the center of the through hole of the light transmitting part, the intensity of the light beam measured by the sensor part is stored, and the intensity of the detected light beam is maximum while changing the height of the sensor part. Focus check unit for determining the point of focus as the focus
Focus measuring device comprising a. The method of claim 1,
The light transmitting unit,
The focus measuring apparatus is made of a metal plate having a predetermined thickness and a through hole is formed in the center of the metal plate. The method of claim 1,
The light transmitting unit and the sensor unit are coupled to both ends of the plurality of gap adjusting members, respectively, the focus measuring device disposed at a predetermined interval. The method of claim 3,
The moving unit,
The light beam is sensed through the through-hole of the light-transmitting part while the light-transmitting part coupled to the sensor part and the sensor part is moved in a plane to move the light-transmitting part together with the sensor part via the sensor part and the gap adjusting member.
Focus measuring device. The method of claim 1,
The focus confirmation unit,
A movement unit designation module for designating a measurement interval in which the movement portion can move at one time;
A movement designation module for designating a movement path to measure the intensity of the light beam while spirally moving the light projector according to the measurement interval designated by the movement unit designation module;
An image conversion module for dividing the intensity of the light beam detected by the sensor unit into a lattice form according to the movement of the moving unit according to a measurement interval and converting the image into an image;
An optical beam intensity storage module for storing the intensity of the light beam measured by the sensor unit and converted by the image conversion module while moving the position of the sensor unit or the position of the light beam up and down;
Focus determination module for comparing the information stored in the light beam intensity storage module to determine the data having the largest intensity in a certain area as the data of the focus
Focus measuring device comprising a. A method for checking the focus of a light beam by using the focus measuring apparatus according to any one of claims 1 to 5,
A first step of irradiating a light beam to pass through a through hole formed in the light transmitting part;
A second step of measuring the intensity of the light beam passing through the through hole and positioning the point where the intensity of the light beam is greatest to be the center of the through hole;
A third step of measuring the intensity of the light beam while moving the light-transmitting part at a predetermined interval about a center of the through-hole to which the light beam is irradiated at a predetermined interval,
The fourth step of measuring the intensity of the light beam while moving the height of the sensor unit or the height of the light beam up and down, and the fifth step of determining the height of the maximum intensity of the light beam in a predetermined region as the focus height
Focus measuring method comprising a. The method of claim 6,
The second step,
Measuring the intensity of the light beam while moving the light transmitting part at regular intervals along a spiral path around the center of the through hole;
Storing the intensity of the light beam measured while the light projector moves in accordance with the movement position of the light projector;
Moving the floodlight so that the center of the through hole is located at a position having the greatest intensity among the stored light beams.
Focus measuring method comprising a.

Images