Patent Publication Number: US-2019178809-A1

Title: Workpiece surface detection method and system using the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a divisional of U.S. application Ser. No. 15/392,325, filed Dec. 28, 2016, which claims the benefit of Taiwan application Serial No. 105135933, filed Nov. 4, 2016, the subject matter of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The technical field relates to a detecting method for a workpiece surface and a system using the same, and more particularly to a detecting method for the misted surface of a workpiece and a system using the same thereof. 
     BACKGROUND 
     In order to detect defects in a surface of a workpiece with high-reflectivity or to measure a size of the workpiece, a common method is to spray the surface of the workpiece with extinction powders for reducing the reflectivity. After the surface defects and the size are shown, the surface of the workpiece is inspected or measured by way of non-contact imaging technique. However, in such method, the extinction powders must be completely removed after inspecting and measuring, and thus it is very time-consuming and difficult, and easily leads to pollution of the production line. Accordingly, it is difficult to be widely used. 
     SUMMARY OF THE DISCLOSURE 
     According to an embodiment of the disclosure, a detecting method for a workpiece surface is provided. The detecting method includes the following steps. A workpiece is provided with a first environment, wherein the first environment has a first environmental temperature higher than a first saturation temperature corresponding to a first environmental relative humidity of the first environment; the workpiece is provided with a gas, wherein the gas has a gas-saturation temperature higher than a itself-temperature of the workpiece for misting a surface of the workpiece; and the surface of the misted workpiece is detected. 
     According to another embodiment of the disclosure, a detecting system for a workpiece surface is provided. The detecting system includes a first air-conditioning module, a gas provider and a detecting module. The first air-conditioning module is configured to provide a workpiece with a first environment, wherein the first environment has a first environmental temperature higher than a first saturation temperature corresponding to a first environmental relative humidity of the first environment. The gas provider is configured to provide the workpiece with a gas, wherein the gas has a gas-saturation temperature higher than an itself-temperature of the workpiece for misting a surface of the workpiece. The detecting module is configured to detect the surface of the misted workpiece. 
     The above and other aspects of the present disclosure will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment (s). The following description is made with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is schematic diagram showing a detecting system for a workpiece surface according to an embodiment of the present disclosure. 
         FIG. 2  is schematic diagram showing a flowchart of a detecting method for a workpiece surface according to an embodiment of the present disclosure. 
         FIG. 3  is schematic diagram showing a diagram of a temperature and humidity curve according to an embodiment of the present disclosure. 
         FIG. 4  is schematic diagram showing a curve of the measured reflectivity of the misted surface of the workpiece. 
         FIG. 5  is schematic diagram showing a diagram of a detecting system for a workpiece surface according to another embodiment of the present disclosure. 
         FIG. 6  is schematic diagram showing a flowchart of a detecting method for a workpiece surface according to another embodiment of the present disclosure. 
         FIG. 7  is schematic diagram showing a diagram of a temperature and humidity curve according to an embodiment of the present disclosure. 
     
    
    
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
       FIG. 1  is schematic diagram showing a diagram of a detecting system  100  for a workpiece surface according to an embodiment of the present disclosure. The detecting system  100  includes a first air-conditioning module  110 , a second air-conditioning module  120 , a mist air-conditioning module  130 , a detecting module  140  and a temperature sensor  150 . 
     In the present embodiment, the first air-conditioning module  110 , the second air-conditioning module  120  and the mist air-conditioning module  130  may separately provide the workpiece  10  with a first environment E 1 , a second environment E 2  and a mist environment Ea for changing a temperature and a humidity of the workpiece  10 , and misting a surface  10   s  of the workpiece  10  by the mist environment Ea. 
     In the present embodiment, the first air-conditioning module  110 , the second air-conditioning module  120  and the mist air-conditioning module  130  are disposed within or interconnect with a first space SP 1 , a second space SP 2  and a mist space SP 3  respectively for controlling the temperature and the humidity of these spaces. In another embodiment, the first air-conditioning module  110 , the second air-conditioning module  120  and the mist air-conditioning module  130  may be disposed within the first space SP 1 , the second space SP 2  and the mist space SP 3  respectively. For example, the first space SP 1 , the second space SP 2  and the mist space SP 3  are three workstations in a production line or three different spaces in a laboratory. 
     In another embodiment, the first air-conditioning module  110 , the second air-conditioning module  120  and the mist air-conditioning module  130  may be integrated into single air-conditioning module. In this embodiment, the first space SP 1 , the second space SP 2  and the mist space SP 3  may be the same space, wherein the single air-conditioning module may provide the same space with different temperature and the humidity at different timing. In addition, the first space SP 1 , the second space SP 2  and/or the mist space SP 3  may be a close space or an open space. 
       FIG. 2  is schematic diagram showing a flowchart of a detecting method for a workpiece surface according to an embodiment of the present disclosure. 
     In step S 110 , referring to  FIGS. 1-3 ,  FIG. 3  shows a diagram of a temperature and humidity curve according to an embodiment of the present disclosure. When the workpiece  10  is located at the first space SP 1 , the first air-conditioning module  110  provides the workpiece  10  with the first environment E 1 . The first air-conditioning module  110  includes a temperature controller and a humidity controller for controlling the temperature and the humidity of the first environment E 1  at a first environmental temperature T e1  and a first environmental relative humidity H e1 , wherein the first environmental temperature T e1  is higher than a first saturation temperature T s1  corresponding to the first environmental relative humidity H e1 . As a result, it can prevent water droplet from being condensed on the surface  10   s  of the workpiece  10 . That is, due to the first environment E 1  being a low humidity environment, it can prevent water droplet from being condensed on the surface  10   s  of the workpiece  10 . 
     In detail, as shown in  FIG. 3 , in the example of the first environmental temperature T e1  being 25° C., and the first environmental relative humidity H e1  being 30%, due to 25° C. being higher than the first saturation temperature T s1  corresponding to relative humidity 30%, that is, 6° C. (in horizontal dotted line toward left direction to correspond to 6° C.), the first environment E 1  is at a lower humidity environment, such that it can prevent water droplet from being condensed on the surface  10   s  of the workpiece  10 . However, as long as water droplet is prevented from being condensed on the surface  10   s  of the workpiece  10 , the value of the first environmental temperature T e1  and the value of the first environmental relative humidity H e1 , are not limited to the embodiment of the present disclosure. 
     In step S 120 , as shown in  FIGS. 1 and 3 , the workpiece  10  is moved to the second space S 2 , and the second air-conditioning module  120  provides the workpiece  10  with the second environment E 2 . The second air-conditioning module  120  may include a temperature controller and a humidity controller for controlling the temperature and the humidity of the second environment E 2  at a second environmental temperature T e2 , wherein the second environmental temperature T e2  is lower than the first environmental temperature T e1  for reducing a itself-temperature T b  to a mist temperature. In an embodiment, the mist temperature may be higher than the second environmental temperature T e2 , or equal to or approaches the second environmental temperature T e2 . 
     In step S 130 , whether the itself-temperature T b  of the workpiece  10  reaches the mist temperature is detected by the temperature sensor  150 , whether the temperature sensor  150  is, for example, non-contact infrared sensor or other non-contact temperature sensor. If the itself-temperature T b  of the workpiece  10  reaches the mist temperature, the step S 140  is performed; if not, the workpiece  10  may be maintained in the second environment E 2  until the itself-temperature T b  of the workpiece  10  is reduced to the mist temperature. In another embodiment, if the itself-temperature T b  of the workpiece  10  has not reached to the mist temperature yet, the second air-conditioning module  120  may reduce the second environmental temperature T e2  to make the workpiece  10  reach to the mist temperature more fast. The aforementioned mist temperature may depend on the mist saturation temperature T sa  of the mist environment Ea; however, such exemplification is not meant to be for limiting. 
     In step S 140 , the mist air-conditioning module  130  provides the workpiece  10  with the mist environment Ea. The mist air-conditioning module  130  may include a temperature controller and a humidity controller for controlling the temperature and the humidity of the mist environment Ea at a mist-environmental relative humidity H ea  and a mist-environmental temperature T ea , wherein a mist-saturation temperature T sa  corresponding to the mist-environmental relative humidity H ea  is equal to or higher than the mist temperature for misting the surface  10   s  of the workpiece  10 . 
     As shown in  FIG. 3 , in the example of the mist temperature being 17° C., if the mist-environmental temperature T ea  is 25° C., the mist air-conditioning module  130  may humidify the mist environment Ea for increasing the mist-environmental relative humidity H ea  to 70% (as shown by point “a” in  FIG. 3 ). As a result, the mist-saturation temperature T sa  corresponding to the relative humidity 70% is about 17° C., and accordingly the surface  10   s  of the workpiece  10  may be misted. In another embodiment, the mist air-conditioning module  130  may humidify the mist environment Ea for increasing the mist-environmental relative humidity H ea  to be higher than 70%, for example, 80% (as shown by point “b” in  FIG. 3 ). The mist-saturation temperature T sa  (about 21° C.) corresponding to the relative humidity 80% is higher than 17° C., and accordingly the surface  10   s  of the workpiece  10  also may be misted. In addition, the aforementioned mist-environmental temperature T ea  may be higher than the mist temperature, and it is not limited to 25° C. 
       FIG. 4  is schematic diagram showing a curve of the reflectivity of the misted surface  10   s  of the workpiece  10 . When the workpiece  10  is a transparent acrylic material with low light transmittance, according to the measured results, the reflectivity of the surface  10   s  of the workpiece  10  is less than 20% (as shown by the curve C 11 ) before the surface  10   s  of the workpiece  10  is misted, but is higher than 20% (as shown by curve C 12 ) after the surface  10   s  of the workpiece  10  is misted. When the workpiece  10  is a reflective sheet having a high light transmittance, according to the measured results, the reflectivity of the surface  10   s  of the workpiece  10  is higher than 80% (as shown by the curve C 21 ) before the surface  10   s  of the workpiece  10  is misted, but is lower than 80% (as shown by curve C 22 ) after the surface  10   s  of the workpiece  10  is misted. 
     In step S 150 , the detecting module  140  inspects and/or measures the misted surface  10   s  of the workpiece  10 . For example, the detecting module  140  includes a robotic arm  141  and an optical detecting component  142 , wherein the optical detecting component  142  is disposed on the robotic arm  141  for being driven by the robotic arm  141  to scan the three-dimensional contours of the surface  10   s  of the workpiece  10  or inspect whether the surface  10   s  has defects. In addition, the detecting module  140  may inspects and/or measures the workpiece  10  within or outside the mist space SP 3 . 
       FIG. 5  is schematic diagram showing a diagram of a detecting system  200  for a workpiece surface according to another embodiment of the present disclosure. The detecting system  200  includes the first air-conditioning module  110 , a gas provider  220 , the detecting module  140  and the temperature sensor  150 . The present embodiment is different from above embodiment in that the gas provider  220  provides the workpiece  10  with mist environment. 
       FIG. 6  is schematic diagram showing a flowchart of an detecting method for a workpiece surface according to another embodiment of the present disclosure. 
     In step S 210 , and referring to  FIG. 7 ,  FIG. 7  is schematic diagram showing a diagram of a temperature and humidity curve according to another embodiment of the present disclosure. When the workpiece  10  is located at the first space SP 1 , the first air-conditioning module  110  provides the workpiece  10  with the first environment E 1 . For example, the first air-conditioning module  110  includes the temperature controller and the humidity controller for controlling the temperature and the humidity of the first environment E 1  at the first environmental temperature T e1  and the first environmental relative humidity H e1  respectively, wherein the first environmental temperature T e1  is higher than the first saturation temperature T s1  corresponding to the first environmental relative humidity H e1 . Due to the first environmental temperature T e1 , the itself-temperature T b  of the workpiece  10  approaches the first environmental temperature T e1 , wherein due to the first environmental temperature T e1  being higher than the first saturation temperature T s1  the itself-temperature T b  of the workpiece  10  is also higher than the first saturation temperature T s1 . Since the itself-temperature T b  of the workpiece  10  is higher than the first saturation temperature T s1 , water droplet is prevented from being condensed on the surface  10   s  of the workpiece  10 , and mist uniformity of the surface  10   s  of the workpiece  10  will not be affected by water droplet. For example, as shown in  FIG. 7 , in the example of the first environmental temperature T e1  being 25° C. and the first environmental relative humidity H e1  being 40%, the first saturation temperature T s1  is 10° C. Thus, as long as the itself-temperature T b  of the workpiece  10  is higher than 10° C., it can prevent water droplet from being condensed on the surface  10   s  of the workpiece  10 . However, as long as water droplet is prevented from being condensed on the surface  10   s  of the workpiece  10 , the value of the first saturation temperature T s1  and value of the first environmental relative humidity H e1  are not limited to the present embodiment. 
     In addition, since the first environmental relative humidity H e1  may be controlled to be lower than the relative humidity outside the first environment E 1 , the first environment E 1  is at a low humidity environment. As a result, even if there is water droplet at the surface  10   s  of the workpiece  10 , the water droplet will evaporate due to the low humidity environment. 
     In step S 220 , whether the itself-temperature T b  of the workpiece  10  is lower than the gas-saturation temperature T ga  of the gas  220   g  (shown in  FIG. 5 ) is detected by the temperature sensor  150 , whether the temperature sensor  150  is, for example, non-contact infrared sensor or other non-contact temperature sensor. If the itself-temperature T b  of the workpiece  10  is lower than the gas-saturation temperature T ga , the step S 230  is performed; if not, the workpiece  10  may be maintained in the first environment E 1  until the itself-temperature T b  of the workpiece  10  is lower than the gas-saturation temperature T ga . Alternatively, the itself-temperature T b  of the workpiece  10  may be much rapidly reduced to be lower than the gas-saturation temperature T ga  of the gas  220   g  by way of reducing the first environmental temperature T e1 . 
     In step S 230 , the gas provider  220  provides the workpiece  10  with the mist environment Ea. For example, the gas provider  220  provides the workpiece  10  with the aforementioned gas  220   g . The gas  220   g  is, for example, vapor or mixture of vapor and gas. The gas provider  220  is, for example, an evaporator, sprayer, or other gas provider capable of providing various temperatures and/or relative humidity. In the example of the relative humidity H eg  of the gas  220   g  being 100%, as shown in  FIG. 7 , due to the gas-saturation temperature T gs  is equal to or higher than the itself-temperature T b  of the workpiece  10 , the surface  10   s  of the workpiece  10  may be misted. For example, in the example of the gas-saturation temperature T gs  of the gas  220   g  being 32° C., since 32° C. is higher than the itself-temperature T b  of the workpiece  10  which is 25° C., for example, and accordingly the surface  10   s  of the workpiece  10  may be misted. In detail, the gas-saturation temperature T gs  of the gas  220   g  is higher than the itself-temperature T b  of the workpiece  10 , and accordingly the gas  220   g  will be condensed on the surface  10   s  of the workpiece  10  when being contacting with the surface  10   s . In addition, the gas  220   g  may include several fine water droplets each having a diameter of 0.1 micrometers to 2 micrometers, such that the surface  10   s  forms a misted surface. 
     In step S 240 , the detecting module  140  inspects and/or measures the misted surface  10   s  of the workpiece  10 . For example, the detecting module  140  includes the robotic arm  141  and the optical detecting component  142  disposed on the robotic arm  141  for being driven by the robotic arm  141  to scan the three-dimensional contours of the surface  10   s  of the workpiece  10  or inspect whether the surface  10   s  has defects. In addition, the detecting module  140  may inspects and/or measures the workpiece  10  within or outside the mist space SP 3 . 
     As described above, an detecting method of an embodiment of the present disclosure provides a dry process (for example, the aforementioned first environment), a cooling process (for example, the aforementioned second environment) and a humidifying and misting process (for example, the aforementioned mist environment), wherein the fine water droplet (misted) is condensed on the surface of the workpiece in the last humidifying and misting process. In another embodiment, a detecting method provides a dry process (for example, the aforementioned first environment) and a gas, wherein the gas-saturation temperature of the gas is higher than a itself-temperature of the workpiece, such that the surface of the workpiece is misted when the gas contacts the surface of the workpiece having relative low temperature and then is condensed. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of the present disclosure provided they fall within the scope of the following claims and their equivalents.