TWI378005B - Automatic focusing apparatus and method - Google Patents

Description

1378005 TW5699PA1 VI. Description of the Invention: [Technical Field] The present invention relates to a polyimaging automatic focusing device and method. The coke device, and especially related to the species [Prior Art] In recent years, with the development of the electronics industry, many consumers such as mobile phones, cameras, projectors, etc. have become more sophisticated. In order to cope with this e-productive filial piety, it is important to have a mainstream market. The processing of key components is also accompanied by many micro-processes, such as drilling, material drilling, material modification, etc. ===plus mode is limited by the size and mechanism of the blade, and gradually replaces the machining method. It is a high-precision, high-speed work, such as laser drilling, laser cutting degree is not due to the ancient surface of the workpiece, b to make the fine focus of the field processing need to == and f ring ' The laser must be processed on the my surface, so that it can be avoided by the work, or the spot area is too large to produce the processing size. The inefficiency needs to be matched with the autofocus module to achieve precision machining. . In order to achieve this, the automatic autofocus method mostly replaces the old mechanical detection to destroy the guardian ^ 2·:·' ::'=light focus (a) auto focus mode, ::; The glimpse usually requires more optical components', so there will be higher costs: = large coke and complicated assembly alignment. —贝#父 3 1378005

TW5699PA [Summary of the Invention] |, hair: There is a kind of auto-focusing device and method, which can judge the defocus of the object to be tested, the volume is small, and the manufacturing cost is low through simple . ^, and installed: two proposed: a kind of autofocus device, including - light source, - concentrating: for sputum, a first focusing element and a second focusing element. The detecting beam is focused into a focused beam, wherein the focused beam is incident on the object to be tested, and is reflected by the object to be reflected to form a reverse: to sense the optical signal. The first focusing element has a -th-focal length =: the material of the reflecting pupil is focused and at the point. The second focusing element has a second focal length and is used to reflect the Li light sensor to form a second spot. The photo sensor cuts off one of the defocus distance and one defocus direction of the object to be tested according to the size change of the first-first point and the size of the second spot. - ttfr further proposes an autofocus method comprising the steps of: providing a primary beam, such that the (four) beam passes through a focusing mirror to form a radiance:,!, the beam is incident on a sample to be detected to form via the object to be tested. Reflecting the beam so that the reflected beam passes through one of the focusing elements without overlapping, to form a -, := "-second spot" on a photosensor, and according to the size of the first spot And the change of the size of the second dot to determine the defocus distance of the object to be tested and the separation of the above-mentioned contents of the present invention is more obvious and easy to understand, the Wente, the 22nd case, and the drawing, Detailed description is as follows: + implementation 137805

I k · · TW5699PA' [Embodiment] Please refer to Fig. 1, which is a flowchart of an autofocus method according to an embodiment of the present invention, the method including steps S11 to S15. Referring to Figure 2, there is shown a schematic diagram of an autofocus device in accordance with an embodiment of the present invention. As shown in Fig. 2, the autofocus device 1 includes a light source 110, a focusing mirror 120, a light sensor 130, a first focusing element 14A, a second focusing element 150 and a beam splitter 160. The autofocus method will be described below with the autofocus device 10 shown in Fig. 2.

As shown in step S11, a detection beam is first provided. As shown in Fig. 2, the light source 110 is used to generate a detection beam. The light source 11 can be a dimming light source or a non-coherent light source. For example, it can be a laser source, a light emitting diode source or a white ray source. Then, as shown in step S12, the detection beam is passed through a focusing mirror to form a focused beam. As shown in Fig. 2, the beam splitter 16 is disposed on the light propagation path of the light source 110 to the photo sensor 130 fa1. The beam splitter 160 refracts the detected and measured light L1 to the focusing mirror 12(). Polyscope: 20 is used to focus the detection beam L1 into a -focus beam L2. Things! After I is as shown in step S13, the focused beam is directed to a beam to be measured, and a reflected beam is formed by the object to be tested. As shown in Fig. 2, the focus is formed to form (4) the posterior yang, which is then finely reflected 160 by the object to be tested. 3. Then, the reflected light beam L3 is again passed through the first mirror 814, so that the reflected light beam passes through one of the non-overlapping ones. As shown in FIG. 2, the first focus 5 1378005 TW5699PA - , the element 140 and the second focusing element 150 are disposed between the beam splitter 160 and the photo sensor 130, and preferably position in front of the photo sensor 130. Light. In addition, the first focusing element 140 is disposed adjacent to the second focusing element 150, and the first focusing element 140 and the second focusing element 150 are the same distance from the photo sensor 130. The photo sensor 130 senses the optical signal after the reflected beam L3 passes through the first focusing element 140 and the second focusing element 150. Preferably, the photo sensor 130 can be a photo diode array (PD Array), a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) light. Sensor. Referring to Fig. 3, the light beam is focused on the photo sensor 130 through the first focusing element 140 and the second focusing element 150 to form a light spot. The first focusing element 140 has a first focal length fl and is used to focus a portion of the reflected beam L3 and form a first spot A on the photo sensor 130. The second focusing element 150 has a second focal length f2 and is used to focus another portion of the reflected beam L3 on the photo sensor 130 to form a second spot B. In the autofocus device 10, the first focusing element 140 is disposed adjacent to the second focusing element 150, and the first focusing element 140 and the second focusing element 150 are at the same distance from the photo sensor 130. In order to make the first spot A and the second spot B have significant dimensional differences, the first focal length fl can be set to be unequal to the second focal length f2. Preferably, as shown in FIGS. 2 and 3, the first focal length fl is smaller than the second focal length f2, and the distance between the photo sensor 130 and the first focusing component 140 and the second focusing component 150 is exactly equal to the first focal length fl Large hour, 1378005 'TW5699PA' The first light spot A is the smallest size, and the first - 氺 - the size of the light spot A. W - the size of the first point 8 is greater than the first # after ^ ^ step Sl5 does not 'according to the size of the first light spot to change the size of the first point of the disk to determine the object to be tested - from the pupil distance direction. As shown in Fig. 2, the distance from the preset distance is two smaller than the focal length of the focusing mirror 120. ^ The position of the light sensing profit 130 may be located at the focus of the focusing mirror 12Q t at the object to be tested 200, so the first light spot; the back side of the focus or the position at which the object is hired changes. The light sensor 13 is therefore available;

The size change of the second pupil and the size change of the second spot 13 are used to determine the defocus distance and a defocus direction of one of the objects 200. For the J lung IT, please refer to the 4th and 5th figures. The 4th figure is the change of the size of the object to be measured from the corresponding spot of the first f detector. The fifth picture is the light spot; intention. The distance of the first focusing element is set to the focal length of the first focusing element (10). Two: When the focus is at the focus position of the focusing mirror 120, the first point on the measuring device 130 is Λ "Different from the figure 4, light perception~ - The first point size is the minimum value. If the second object is not moved, when the object to be tested 200 moves to the focus image of the object 200 and the focusing mirror 12 ' 'the distance of the object to be tested when the object to be tested is away from the focal length of the focal lens' Focus, mirror state. Conversely 'When the defocused state of the object to be tested 200 is said to be:: ':12〇: focal length' at this time, the divination of the earthworms is a bit of resentment. As shown in Figures 4 and 5... Indeed, in the edge-focus state or near-focus state, the first - 'gets bigger. So - the m* occupies a spot size will know the change of the spot size of the object to be measured. 7 1378005

TW5699PA However, as shown in Figures 4 and 5, since the spot size of the first spot A corresponds to one defocus position of the near focus and the far focus at the same time, only analyzing the size change of the first spot A will only be able to The defocus distance of the object to be tested is not enough to know the direction of defocus of the object to be tested 200. Through the appropriate optical design, the object 200 can be placed at a defocus position of the focusing mirror 12, at which time the second spot B of the photosensor 130 receives the minimum value. As shown in Fig. 4, the size of the second spot B is the minimum when the object to be tested 2 is located at a near-focal distance. In other words, when the object to be tested 2 is moved back and forth with respect to the defocus position X in the optical axis direction of the focusing mirror 120, the size of the second spot b on the photo sensor 120 will become large. Therefore, in the step of determining the defocusing distance and the defocusing direction of the object to be tested 2 in step S15, the first focusing element 14 may be provided when the object to be tested is at the point of the poly f and the mirror 20 A light spot is formed on the photo sensor 13 (); the first pre-size is again, and the second focusing element 150 is in the photo sensor! The second predetermined size n is set to be the light spot size S1 of the fourth image_the first light spot A at the focus, and the second predetermined size is the second light spot B of the focus point. The spot size on the spot is S2. Then, the first light spot size and the first predetermined ruler τ (light spot size SI) are compared to estimate the defocus distance of the object to be tested. Let's say 'Kogen' (4) - the difference between the silk and the first - preset size to calculate the actual defocus distance of the object to be tested 200. Then, according to the relationship between the second spot size and the second preset size (light S2), the fine defocus direction of the object to be tested is judged. For example, 4th, $Fig ::: When the object to be tested is at the far focus position, the light of the second spot β is greater than the spot size S2. Therefore, when the second spot size is larger than the second TW5699PA': it can be judged that the object 2 〇〇 is in a far focus position and the object 'two points are smaller than the second preset size' The sputum is in the near-focus position. Since the size change of the first spot Α of the first focusing element 140 and the second spot B of the second focusing point corresponds to the object to be tested 2: from: 3 is not the same 'the first light spot A and the second light spot The size of B changes: shape: complementary analysis, so that 'through the comprehensive analysis of the double-spot size text: the main will be able to quickly find the defocus distance and defocus direction of the object to be measured 2 —. - Please refer to them' In the optical simulation of the recording, the first focusing element 140 disc 2 focuses the individual lens parameters of the component 15G. In addition, the light source u〇 uses a better coherent laser _, the human beam diameter is about 5 coffee, the first t focal unit M0, the third focusing element 15〇=the distance from the photo sensor (10) is about 8.5_, the focusing mirror! After 2〇, the focal length ((10) handsome) is about 2_6_, and the distance between the focusing mirror 12〇 and the object to be side is about 2 Yang. iJ.

The first focusing element 150 according to the experimental result 'When the object to be tested 2 is clamped at the focus position, the spot size of the light spot A is about 2 mm in length, and the spot size of the light spot B is The diameter is about 4 grids. When the object to be tested is hired at a far position, the spot diameter of the first spot A is about 2 grids. 1378005 TW5699PA · * The spot diameter of the second spot B is about 5 grids. When the object to be tested is 200 bits at a near focus position of about 400 μm, the spot diameter of the first spot A is also 2 cells, and the spot diameter of the second spot B is about 3 grids. Therefore, the optical focusing apparatus and method of the present embodiment are indeed feasible techniques through optical simulation and experimental verification. The above description of the present embodiment is mainly based on the structure of Fig. 2, but the autofocus apparatus and method of the present invention are not limited thereto. Please refer to Figure 6, which is a schematic diagram of the autofocus device with other optical path designs. The beam splitter 260 of the autofocus device 20 of Fig. 6 is different in design from the beam splitter 160. As shown in Fig. 2, the focusing mirror 120 is disposed on one side of the beam splitter 160, and the first focusing element 140 and the second focusing element 150 are disposed on the opposite side of the focusing mirror 120. However, in Fig. 6, the focusing mirror 120 is disposed on one side of the dichroic mirror 260, and the light source 110 is disposed on the opposite side of the focusing mirror 120. The detecting beam L1 can penetrate the beam splitter 260 and then pass through the focusing mirror 120 to form a focused beam L2. The focused beam L2 is then incident on the object to be tested 200, and then reflected by the object to be tested 200 to form a reflected beam L3. Thereafter, the reflected light beam L3 is refracted by the beam splitter 260 to the first focusing element 140 and the second focusing element 150, and the first focusing element 140 and the second focusing element 150 form different spots on the photo sensor 130. Although the above embodiment has been described with different focal lengths of the first focusing element 140 and the second focusing element 150, the present invention is not limited thereto. Please refer to Fig. 7, which is a schematic diagram of the autofocus device with other focusing component configurations. The first focusing element 340 of the autofocus device 30 has the same focal length as the second focusing element 350. However, the distance between the first focusing element 340 and the second focusing element 350 is different from that of the photo sensor 130, 1378005

TW5699PA is used to generate the defocusing array of different well points 200. The effect 'Therefore, it can also be judged that the focusing component of the object to be tested is more visible to the needs of the device - the micro-transparent ^ ^ ^ ^ ^: The embodiment disclosed in the article The autofocus device and method are directed to the object to be tested, and the reflection generated by the object to be tested is two reflections: two adjacent focusing elements with different focal lengths, or The same focusing element with different distance from the light sensor forms two light spots of different sizes on the light sensing, which are changed by the two spot sizes; 2 to determine the degree of defocus of the object to be tested Defocus direction. Since the focusing component of the optical path can judge the defocusing of the object to be tested: the structure of the paying and focusing device is simple, but still provides high-precision measurement, and makes assembly of the device easier, and can achieve effective volume reduction and Reduce the cost. In summary, although the invention has been disclosed, for example, it is not intended to limit the invention. It will be apparent to those skilled in the art that the present invention can be practiced in various ways without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing an autofocus method in accordance with an embodiment of the present invention. "' / Figure 2 is a schematic diagram of an autofocus device in accordance with an embodiment of the present invention. Figure 3 shows a beam passing through a first focusing element and a second focusing element 俨1378005 TW5699PA 1 1 coke formed on the photo sensor Schematic diagram of the light spot. Fig. 4 is a diagram showing the change of the size of the light spot on the photosensor according to the defocus state of the object to be tested. Fig. 5 is a schematic view of the light spot in different defocus states. Fig. 6 is an autofocus device Schematic diagram of other optical path design. Fig. 7 is a schematic diagram of the autofocus device with other focusing component configurations. [Main component symbol description] 10, 20, 30: autofocus device 110: light source 120: focusing mirror 130: photo sensor 140, 340: first focusing element 150, 350: second focusing element 160, 260: beam splitter 200: object to be tested A: first spot B: second spot L1 detecting beam L2 focusing beam L3 reflecting beam

Claims (1)

1378005 101. 07.24.24 Revision replacement page 2012/7/24_la Application & Amendment 7. Scope of application: 1. An autofocus device comprising: a light source for generating a detection beam; a focusing mirror And focusing the detection beam into a focused beam, wherein the focusing mirror has a focus, the focused beam is incident on an object to be tested, and is reflected by the object to be reflected to form a reflected beam; a detector for sensing an optical signal; a first focusing element having a first focal length, the first focusing element for focusing a portion of the reflected beam to form a first spot on the photo sensor; and a second focusing element Having a second focal length, the second focusing element is configured to focus another portion of the reflected beam to form a second spot on the photo sensor, wherein the photo sensor is configured according to the photo sensor The size change of the first spot and the size change of the second spot determine a defocus distance and a defocus direction of the object to be tested, and the first focusing element is disposed adjacent to the second focusing element. 2. The autofocus device of claim 1, wherein the position of the object to be tested is at a front side of the focus of the focusing mirror, a rear side of the focus, or the focus. 3. The autofocus device of claim 1, further comprising a beam splitter disposed on the light propagation path of the light source to the light sensor. 4. The autofocus device of claim 3, wherein the focusing mirror is disposed on one side of the beam splitter, and the first focusing element and the second focusing element are disposed opposite to the focusing mirror One side. 098 143 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098 098. It is disposed on one side of the beam splitter, and the light source is disposed on the opposite side of the focusing mirror. 6. The autofocus device of claim 1, wherein the first focusing element and the second focusing element are at the same distance from the photo sensor, and the first focal length is not equal to the second focal length. 7. The autofocus device of claim 6, wherein the first focal length is less than the second focal length. 8. The autofocus device of claim 1, wherein the distance between the first focusing element and the photo sensor is not equal to the distance between the second focusing element and the photo sensor, and the A focal length is equal to the second focal length. The autofocus device of claim 1, wherein the light source is a dimming light source or a non-coinciding light source. 10. The autofocus device of claim 1, wherein the light source is a laser source, a light emitting diode source or an incandescent source. 11. The autofocus device of claim 1, wherein the photo sensor is a photo diode array (PD Array), a charge-coupled device (CCD) Or a complementary metal oxide semiconductor (CMOS) photosensor. 12. The autofocus device of claim 1, wherein the first focusing element and the second focusing element form a microlens array. 14 098143988 1013282538-0 I.37S005 Amendment page 2012/7/24_la, Reb. & Amendment, 13. Autofocus method, comprising: providing a detection beam; passing the detection beam through a focusing mirror to form a focused beam Causing the focused beam to an object to be tested to form a reflected beam through the object to be tested; causing the reflected beam to pass through one of the first focusing element and a second focusing element without overlapping one of the photo sensors Forming a first light spot and a second light spot respectively; and determining a defocus distance and a defocusing direction of the object to be tested according to a change in the size of the first spot and a change in the size of the second spot The step of determining the defocus distance and the defocus direction of the object to be tested includes: providing the object to be tested at a focus of the focusing mirror, the first focusing component being on the photo sensor Forming a first predetermined size of one of the light spots, and a second predetermined size of the light spot formed by the second focusing element on the light sensor; comparing the first spot size with the first preset Dimension to estimate the defocus distance of the object to be tested According to the second spot size the size relationship with the second predetermined power to determine the direction of the object to be measured from. The autofocus method of claim 13, wherein the first focal length of one of the first focusing elements is smaller than the second focal length of the second focusing element, and the determination of the object to be tested is determined In the step of focusing direction: when the second spot size is larger than the second preset size, determining that the object to be tested is in a far focus position; 15 098143988 1013282538-0 ········ 1378005 __v On July 24, 101, B shuttle spring change for mu · 2012/7/24_lsl Shen Fu & correction, when the second spot size is smaller than the second preset size, it is judged that the object to be tested is in a near focus position . 098143988· 1013282538-0 16