CN211563743U

CN211563743U - Appearance detection equipment

Info

Publication number: CN211563743U
Application number: CN201921876173.4U
Authority: CN
Inventors: 汤尔英; 蒋萍琴; 余雷
Original assignee: Dongguan Shengxiang Precision Metal Co Ltd
Current assignee: Dongguan Shengxiang Precision Metal Co Ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-09-25
Anticipated expiration: 2029-10-31

Abstract

The utility model discloses an outward appearance check out test set, bear device, detection device and double-layered material turning device including the board and set up in the material spare of board, material spare bears device movably and installs in the board and cooperatees with detection device, and detection device is a plurality of, and a plurality of detection device are used for detecting the top surface, side and the bottom surface of material spare that material spare bears the weight of respectively, press from both sides material turning device and install in one of them detection device's below, press from both sides material turning device and material spare and bear the weight of the device and cooperate for 180 with material spare upset. This outward appearance check out test set possesses the detection function at 360 no dead angles to can be adapted to the detection of the tiny precision spare part in batches, detection efficiency is high, fast, detection data is accurate.

Description

Appearance detection equipment

Technical Field

The utility model relates to a detect mechanical equipment field, in particular to outward appearance check out test set.

Background

A mobile phone, also called a mobile phone or a wireless phone, is a communication tool, and is a portable phone terminal that can be used in a wider range.

In the manufacturing process of the mobile phone, a lot of fine and precise parts are involved, and when the parts are processed or used, appearance detection is required to be carried out on the parts, and defective products are removed. At present, the appearance detection and identification of these parts are mostly performed by manual eyes, but because these fine and precise parts are small in size and large in quantity, and the parts are generally different in size, and the appearance of the parts is basically indistinguishable from each other (for example, circular ring-shaped parts), a manual detection or a manual detection combined with auxiliary equipment requires a high degree of concentration for a long time, and along with the supply of light sources, long-time work is accompanied, workers are prone to distract or various careless mistakes due to visual fatigue, and finally the detection quality cannot be ensured, and the work efficiency is low.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an outward appearance check out test set that detection efficiency is high, degree of automation is high can solve one of the above-mentioned problem at least.

According to the utility model discloses an aspect provides an outward appearance check out test set, bear the device including the board and set up in the material spare of board, detection device and double-layered material turning device, material spare bears device movably to install in the board and cooperate with detection device, detection device is a plurality of, a plurality of detection device are used for detecting the top surface, side and the bottom surface of the material spare that material spare bears the weight of respectively, press from both sides material turning device and install in one of them detection device's below, press from both sides material turning device and cooperate with material spare bearing device for 180 with material spare upset.

Therefore, the utility model discloses an outward appearance check out test set's theory of operation does: the material part bearing device is used for bearing the material part and conveying the material part to the detection area of each detection device for detection, the plurality of detection devices respectively detect the top surface, the side surface and the bottom surface of the material part comprehensively, and immediately after the detection of each detection device is finished, the uploaded data is compared with the rated value of the system, and whether the material part is good or not is immediately distinguished.

The utility model discloses an outward appearance check out test set possesses the detection function at 360 no dead angles to can be adapted to the detection of the tiny accurate spare part in batches, detection efficiency is high, fast, detection data is accurate.

In some embodiments, the number of the detection devices is three, and the detection devices are respectively a first detection device, a second detection device and a third detection device, the first detection device, the second detection device and the third detection device are sequentially arranged, the material loading device can drive the material to move among the first detection device, the second detection device and the third detection device, the first detection device is used for detecting the top surface of the material, the second detection device is used for detecting the side surface of the material, and the third detection device is used for detecting the bottom surface of the material. Therefore, the utility model discloses set up three detection device altogether, carry out the comprehensive detection at 360 no dead angles to the top surface, the side and the bottom surface of material piece respectively, guarantee non-defective products material spare after the detection flaw, high-quality.

In some embodiments, the detection device further includes a mounting bracket, the first detection device and the third detection device are respectively installed at the front end and the rear end of the mounting bracket and located above the material loading device, the first detection device includes a first detection lens and a first compensation light source, the first detection lens and the first compensation light source are both installed at the front end of the mounting bracket, and the first compensation light source is located below the first detection lens, the third detection device includes a third detection lens and a third compensation light source, the third detection lens and the third compensation light source are both installed at the rear end of the mounting bracket, and the third compensation light source is located below the third detection lens. From this, each detection device all is provided with corresponding compensation light source, and the light source that bears the weight of the device with the material spare combines together, and the light source is sufficient, and then guarantees the shooting quality of detection camera lens, improves the degree of accuracy of comparing.

In some embodiments, the second detecting device is located between the first detecting device and the third detecting device, the second detecting device includes a plurality of second detecting lenses and a second compensating light source, the plurality of second detecting lenses are installed around the material loading device, and the second compensating light source is installed on the mounting frame and located above the material loading device. From this, the second inspection camera lens sets up to a plurality ofly, can guarantee that the side of material spare all detects, and then realizes the detection function at 360 no dead angles.

In some embodiments, the material loading device includes a moving module, a light source module, and a material positioning and rotating module, the moving module is installed on the machine, the material positioning and rotating module is installed on the moving module, the light source module is installed on the material positioning module, the material is placed on the material positioning and rotating module, and the moving module is used for driving the material positioning and rotating module and the material placed thereon to move between the plurality of detection devices. From this, remove the module and be used for driving light source module and the rotatory module of material location to remove to corresponding detection device's detection area, the light source module provides sufficient light source for detection device, and the rotatory module of material location is used for bearing weight of material and carries out certain angle's rotation to the material when carrying out the side and detecting.

In some embodiments, the material positioning and rotating module includes a first driving member, a first mounting block, a first gear, a second gear, a rotating shaft, an optical glass, and a positioning seat, the first mounting block is mounted on the moving module, the first driving member, the first gear, the second gear, and the light source module are mounted on the first mounting block, one end of the first driving member is connected to the first gear, the second gear is engaged with the first gear, the second gear is sleeved on the periphery of the rotating shaft, the positioning seat is mounted on the rotating shaft, and the optical glass is sleeved on the periphery of the positioning seat and is located right above the light source module. Therefore, when the material part needs to be rotated, the first driving part drives the first gear to rotate, the second gear is driven to rotate, the rotating shaft is driven to rotate together with the positioning seat arranged on the rotating shaft, and the rotation of the material part is completed. The light source of the light source module can penetrate through the optical glass and then is matched with the detection lens to complete detection.

In some embodiments, the light source module includes a first light source and a second light source, the second light source is disposed at an outer periphery of the first light source, the first light source is an annular light source, and the second light source is a square light source. Therefore, the utility model discloses a light source module includes two kinds of shapes, luminance and the different light sources of light source colour, can satisfy different detection demands.

In some embodiments, the clamping and turning device comprises a second mounting block, a clamping jaw cylinder, a rotating cylinder, a lifting adjusting cylinder and a front and back feeding cylinder, wherein the clamping jaw is mounted on the clamping jaw cylinder, the clamping jaw cylinder is mounted on the rotating cylinder, the rotating cylinder is mounted on the lifting adjusting cylinder, the lifting adjusting cylinder is mounted on the front and back feeding cylinder, and the front and back feeding cylinder is fixedly mounted on the machine table through the second mounting block. From this, press from both sides material turning device's theory of operation does: when the material part needs to be turned over, the front and back feeding cylinder, the lifting adjusting cylinder and the clamping jaw cylinder drive the clamping jaw together to clamp the material part on the positioning seat of the material part positioning and rotating module, then the material part ascends under the driving of the lifting adjusting cylinder, the clamping jaw is driven by the rotating cylinder and the clamped material part rotates 180 degrees together, then the material part descends under the driving of the lifting adjusting cylinder and is loosened under the driving of the clamping jaw cylinder to place back the positioning seat, and finally the material part resets to return to the initial position.

In some embodiments, the appearance detection device further comprises a control device, the control device is disposed on the machine table, and the control device is connected with the material loading device, the detection device and the material clamping and turning device and is used for controlling the work of the material loading device, the detection device and the material clamping and turning device. Therefore, the control device can be a computer, and each device is controlled by an embedded program so as to ensure the automation of each device.

The utility model has the advantages that:

Drawings

Fig. 1 is a schematic perspective view of an appearance inspection apparatus according to an embodiment of the present invention;

FIG. 2 is a simplified perspective view of the appearance inspection apparatus shown in FIG. 1;

fig. 3 is a schematic top view of the appearance inspection apparatus shown in fig. 2;

FIG. 4 is a schematic perspective view of the light source module and the material positioning and rotating module of the appearance inspection apparatus shown in FIG. 2;

FIG. 5 is a second schematic perspective view of the light source module and the material positioning and rotating module of the appearance inspection apparatus shown in FIG. 2;

fig. 6 is a schematic perspective view of the clamping and turning device of the appearance inspection apparatus shown in fig. 2.

Reference numerals in fig. 1 to 6: 1-a machine platform; 2-a material carrying device; 3-a detection device; 4-clamping and turning device; 5-material part; 21-a moving module; 22-a light source module; 23-a material positioning and rotating module; 31-a first detection device; 32-a second detection device; 33-a third detection device; 34-a mounting frame; 41-a second mounting block; 42-a clamping jaw; 43-gripper cylinder; 44-a rotary cylinder; 45-lifting adjusting cylinder; 46-front and rear feed cylinders; 221-a first light source; 222-a second light source; 231-a first driving member; 232-a first mounting block; 233-a first gear; 234-a second gear; 235-optical glass; 236-a positioning seat; 311-a first detection shot; 312 — a first compensating light source; 321-a second detection lens; 322-a second compensating light source; 331-third detection shot; 332-third compensating light source.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Fig. 1 to 6 schematically show an appearance inspection apparatus according to an embodiment of the present invention.

As shown in fig. 1 to 6, the appearance inspection apparatus includes a machine table 1, and a material loading device 2, an inspection device 3, a material clamping and turning device 4, and a control device, which are disposed on the machine table 1. The material loading device 2 is movably installed on the machine table 1 and is matched with the detection device 3. The detecting devices 3 are multiple, and the detecting devices 3 are respectively used for detecting the top surface, the side surface and the bottom surface of the material 5 carried by the material carrying device 2. The clamping and turning device 4 is arranged below one of the detection devices 3. The clamping and overturning device 4 is matched with the material loading device 2 and is used for overturning the material 5 by 180 degrees. The control device is disposed on the machine platform 1. The control device is connected with the material bearing device 2, the detection device and the material clamping and overturning device 4 and is used for controlling the work of the material bearing device 2, the detection device 3 and the material clamping and overturning device 4. Therefore, the control device can be a computer commonly used in the market, and each device is controlled by an embedded program so as to ensure the automation of each device.

As shown in fig. 2 and 3, the number of the detection devices 3 in the present embodiment is three, and the detection devices are a first detection device 31, a second detection device 32, and a third detection device 33. The first detecting means 31, the second detecting means 32 and the third detecting means 33 are arranged in this order. The material loading device 2 can drive the material 5 to move among the first detection device 31, the second detection device 32 and the third detection device 33. The first detection device 31 is used for detecting the top surface of the material piece 5; the second detection device 32 is used for detecting the side surface of the material part 5; the third detecting device 33 is used for detecting the bottom surface of the material 5. From this, set up three detection device, carry out 360 comprehensive detections that do not have the dead angle to the top surface, the side and the bottom surface of material spare 5 respectively, guarantee the non-defective products material spare after the detection defect, high-quality.

The detection device 3 further comprises a mounting frame 34. The first detection device 31 and the third detection device 33 are respectively installed at the front end and the rear end of the installation frame 34 and are located above the material loading device 2. The first detection device 31 includes a first detection lens 311 and a first compensation light source 312. The first detection lens 311 and the first compensation light source 312 are both mounted at the front end of the mounting frame 34, and the first compensation light source 312 is located below the first detection lens 311. The third detection device 33 includes a third detection lens 331 and a third compensation light source 332. The third detection lens 331 and the third compensation light source 332 are both mounted at the rear end of the mounting frame 34, and the third compensation light source 332 is located below the third detection lens 331. From this, each detection device all is provided with corresponding compensation light source, and the light source that bears device 2 with the material spare combines together, and the light source is sufficient, and then guarantees the shooting quality of detection camera lens, improves the degree of accuracy of comparing.

The second detection means 32 are located between the first detection means 31 and the third detection means 33. The second detection device 32 includes a second detection lens 321 and a second compensation light source 322. The number of the second detecting lenses 321 is plural, and the plural second detecting lenses 321 are installed around the material loading device 2. The second compensating light source 322 is mounted on the mounting frame 34 and above the material loading device 2. As shown in fig. 3, the number of the second detection lenses 321 in the present embodiment is 4, and the 4 second detection lenses 321 are respectively installed around the second compensation light source 322. From this, second inspection camera lens 321 sets up to a plurality ofly, can guarantee that the side of material all detects, and then realizes the detection function at 360 no dead angles.

As shown in fig. 1 and 2, the first inspection lens 311, the second inspection lens 321, and the third inspection lens 331 of the present embodiment can be finely adjusted to meet practical requirements. Can be realized by the matching of structures such as a sliding block, an adjusting nut and the like.

As shown in fig. 2 and fig. 4 to 5, the material loading device 2 includes a moving module 21, a light source module 22 and a material positioning and rotating module 23. The moving module 21 is installed on the machine table 1, the material positioning and rotating module 23 is installed on the moving module 21, and the light source module 22 is installed on the material positioning module. The material 5 is placed in the material positioning and rotating module 23. The moving module 21 is used for driving the part positioning rotating module 23 and the parts 5 placed thereon to move among the plurality of detecting devices. The moving module 21 of the present embodiment may be a conventional linear motion assembly, such as a linear motion assembly composed of a lead screw, a nut, a slider, and a guide rail. From this, the removal module 21 is used for driving light source module 22 and material piece location rotation module 23 to move to corresponding detection device's detection area, and light source module 22 provides sufficient light source for detection device, and material piece location rotation module 23 is used for bearing material piece 5 and carries out certain angle's rotation to material piece 5 when carrying out the side detection.

As shown in fig. 4 and 5, the workpiece positioning and rotating module 23 includes a first driving member 231, a first mounting block 232, a first gear 233, a second gear 234, a rotating shaft, an optical glass 235 and a positioning seat 236. The first mounting block 232 is mounted to the moving module 21. The first driving member 231, the first gear 233, the second gear 234 and the light source module 22 are all mounted on the first mounting block 232. One end of the first driving member 231 is connected to the first gear 233, and the second gear 234 is engaged with the first gear 233. The second gear 234 is fixedly sleeved on the periphery of the rotating shaft, and the positioning seat 236 is fixedly installed on the upper end of the rotating shaft. The optical glass 235 is sleeved on the periphery of the positioning seat 236 and is located right above the light source module 22. Since the material piece of the present embodiment is circular, the positioning seat 236 has a cylindrical structure. Therefore, when the material part needs to be rotated, the first driving member 231 drives the first gear 233 to rotate, and drives the second gear 234 to rotate, so as to drive the rotating shaft and the positioning seat 236 mounted on the rotating shaft to rotate together, thereby completing the rotation of the material part. The light source of the light source module 22 can penetrate through the optical glass 235, and then cooperate with the inspection lens to complete the inspection.

As shown in fig. 4, the light source module 22 includes a first light source 221 and a second light source 222. The second light source 222 is disposed at the outer circumference of the first light source 221. The first light source 221 is a ring light source, and the second light source 222 is a square light source. Therefore, the utility model discloses a light source module 22 includes two kinds of shapes, luminance and the different light sources of light source colour, can satisfy different detection demands.

As shown in fig. 2 and 6, the material clamping and turning device 4 of the present embodiment includes a second mounting block 41, a clamping jaw cylinder 43, a rotary cylinder 44, an elevation adjustment cylinder 45, and a front and rear feed cylinder 46. The clamping jaw is arranged on a clamping jaw air cylinder 43, the clamping jaw air cylinder 43 is arranged on a rotary air cylinder 44, the rotary air cylinder 44 is arranged on a lifting adjusting air cylinder 45, the lifting adjusting air cylinder 45 is arranged on a front and back feeding air cylinder 46, and the front and back feeding air cylinder 46 is fixedly arranged on the machine table 1 through a second mounting block 41. The jaw cylinder 43 can drive the jaws to open or close. The clamping jaw air cylinder 43, the rotating air cylinder 44, the lifting adjusting air cylinder 45, the front and rear feeding air cylinders 46 and the like are all commonly used air cylinders in the market. From this, press from both sides material turning device 4's theory of operation does: when the material 5 needs to be turned over, the front and back feeding air cylinder 46, the lifting adjusting air cylinder 45 and the clamping jaw air cylinder 43 drive the clamping jaws to clamp the material on the positioning seat 236 of the material positioning and rotating module 23 together, then the clamping jaws are driven by the lifting adjusting air cylinder 45 to ascend, the rotating air cylinder 44 drives the clamping jaws and the clamped material 5 to rotate 180 degrees together, then the clamping jaws descend under the driving of the lifting adjusting air cylinder 45 and loosen the material 5 under the driving of the clamping jaw air cylinder 43 to put back the positioning seat 236, and finally the clamping jaws are reset to the initial position.

According to another aspect of the present invention, there is provided a method for detecting the appearance detecting device, comprising the steps of:

s1, feeding: the material part 5 is placed on the positioning seat 236 of the material part carrier 2 by a robot or manually.

S2, top surface detection: the material 5 is driven by the moving module 21 of the material bearing device 2 to move to the detection area of the first detection device 31, the first detection device 31 detects the top surface of the material 5, the detection result is compared with the system rated value in the control device database, the detection is continued if the requirement is met, and the rejection is performed if the requirement is not met.

During the top surface inspection, the light source module 22 of the material loading device 2 and the first compensation light source 312 of the first inspection device 31 provide light simultaneously to ensure the shooting quality of the first inspection lens 311.

S3, side surface primary detection: the material 5 is driven by the moving module 21 of the material bearing device 2 to move to the detection area of the second detection device 32, the second detection device 32 detects the side surface of the material 5 for the first time, and compares the detection result with the system rated value in the control device database, if the detection result meets the requirement, the detection is continued, and if the detection result does not meet the requirement, the rejection is performed.

S4, secondary side detection: the material 5 is driven by the first driving part 231 of the material positioning and rotating module 23 to rotate 45 degrees, the second detection device 32 carries out second detection on the side surface of the material 5, the detection result is compared with a system rated value in the control device database, the detection is continued if the detection result meets the requirement, and the rejection is carried out if the detection result does not meet the requirement.

During the side detection, the light source module 22 of the material loading device 2 and the second compensation light source 322 of the second detection device 32 provide light simultaneously, so as to ensure the shooting quality of the second detection lens 321. The reason for carrying out secondary detection on the side surface is to detect the side surface everywhere as far as possible, and omission caused by the existence of a shooting blind area is avoided.

S5, overturning the material: the material piece 5 is turned for 180 degrees under the action of the material clamping and turning device, the bottom surface of the material piece faces upwards, and the material piece is placed on the positioning seat 236 again.

S6, bottom surface detection: the material 5 is driven by the moving module 21 of the material bearing device 2 to move to the detection area of the third detection device 33, the third detection device 33 detects the bottom surface of the material 5, and compares the detection result with the system rated value in the control device database, if the detection result meets the requirement, the material is good, and if the detection result does not meet the requirement, the material is rejected.

During the bottom surface detection, the light source module 22 of the material loading device 2 and the third compensation light source 332 of the third detection device 33 provide light simultaneously, so as to ensure the shooting quality of the third detection lens 331.

S7, resetting the material piece carrying device 2: the material loading device 2 is driven by the moving module 21 to move to the front of the first detecting device 31 to wait for feeding.

S8, repeating the steps S1-S7.

The utility model discloses a detection method of outward appearance check out test set is brand-new detection method, has replaced traditional artifical naked eye to detect, the mode of differentiateing, and detection efficiency is high, the testing result is accurate, degree of automation is high.

What has been described above are only some embodiments of the invention. For those skilled in the art, without departing from the inventive concept, several modifications and improvements can be made, which are within the scope of the invention.

Claims

1. The utility model provides an outward appearance check out test set, its characterized in that includes board (1) and sets up in material spare of board (1) bears device (2), detection device (3) and presss from both sides material turning device (4), material spare bears device (2) movably install in board (1) and cooperate with detection device (3), detection device (3) are a plurality of, and are a plurality of detection device (3) are used for detecting top surface, side and the bottom surface of material spare (5) that material spare bears device (2) respectively, it installs in the below of one of them detection device (3) to press from both sides material turning device (4) and material spare bears device (2) and cooperate for 180 with material spare (5) upset.

2. The appearance inspection apparatus according to claim 1, wherein the number of the inspection devices (3) is three, and the inspection devices are respectively a first inspection device (31), a second inspection device (32) and a third inspection device (33), the first inspection device (31), the second inspection device (32) and the third inspection device (33) are sequentially arranged, the material carrying device (2) can drive the material to move among the first inspection device (31), the second inspection device (32) and the third inspection device (33), the first inspection device (31) is used for inspecting the top surface of the material (5), the second inspection device (32) is used for inspecting the side surface of the material (5), and the third inspection device (33) is used for inspecting the bottom surface of the material (5).

3. The appearance inspection device according to claim 2, characterized in that said inspection means (3) further comprise a mounting frame (34), the first detection device (31) and the third detection device (33) are respectively arranged at the front end and the rear end of the mounting frame (34) and are positioned above the material part bearing device (2), the first detection device (31) comprises a first detection lens (311) and a first compensation light source (312), the first detection lens (311) and the first compensation light source (312) are both arranged on the mounting frame (34) and the first compensation light source (312) is positioned below the first detection lens (311), the third detection device (33) comprises a third detection lens (331) and a third compensation light source (332), the third detection lens (331) and the third compensation light source (332) are both mounted on the mounting frame (34), and the third compensation light source (332) is located below the third detection lens (331).

4. The appearance inspection apparatus according to claim 3, wherein the second inspection device (32) is located between the first inspection device (31) and the third inspection device (33), the second inspection device (32) includes a plurality of second inspection lenses (321) and a second compensation light source (322), the plurality of second inspection lenses (321) are installed around the material loading device (2), and the second compensation light source (322) is installed on the mounting frame (34) and located above the material loading device (2).

5. The appearance detection equipment according to claim 1, wherein the material carrying device (2) comprises a moving module (21), a light source module (22) and a material positioning and rotating module (23), the moving module (21) is installed on the machine platform (1), the material positioning and rotating module (23) is installed on the moving module (21), the light source module (22) is installed on the material positioning module, the material (5) is placed on the material positioning and rotating module (23), and the moving module (21) is used for driving the material positioning and rotating module (23) and the material (5) placed thereon to move among the plurality of detection devices (3).

6. The appearance inspection apparatus according to claim 5, wherein the material positioning rotation module (23) comprises a first driving member (231), a first mounting block (232), a first gear (233), a second gear (234), a rotation shaft, an optical glass (235), and a positioning base (236), the first mounting block (232) is mounted on the moving module (21), the first driving piece (231), the first gear (233), the second gear (234) and the light source module (22) are mounted on the first mounting block (232), one end of the first driving piece (231) is connected with the first gear (233), the second gear (234) is meshed with the first gear (233), the second gear (234) is sleeved on the periphery of the rotating shaft, the positioning seat (236) is arranged on the rotating shaft, the optical glass (235) is sleeved on the periphery of the positioning seat (236) and is positioned right above the light source module (22).

7. The appearance inspection apparatus according to claim 6, wherein the light source module (22) comprises a first light source (221) and a second light source (222), the second light source (222) is disposed at an outer periphery of the first light source (221), the first light source (221) is a ring light source, and the second light source (222) is a square light source.

8. The appearance detection device according to claim 1, wherein the clamping and turning device comprises a second mounting block (41), a clamping jaw (42), a clamping jaw cylinder (43), a rotary cylinder (44), a lifting adjusting cylinder (45) and a front and back feeding cylinder (46), the clamping jaw (42) is mounted on the clamping jaw cylinder (43), the clamping jaw cylinder (43) is mounted on the rotary cylinder (44), the rotary cylinder (44) is mounted on the lifting adjusting cylinder (45), the lifting adjusting cylinder (45) is mounted on the front and back feeding cylinder (46), and the front and back feeding cylinder (46) is fixedly mounted on the machine table (1) through the second mounting block (41).

9. The appearance detection equipment according to any one of claims 1 to 8, further comprising a control device, wherein the control device is disposed on the machine table (1), and the control device is connected to the material loading device (2), the detection device (3) and the material clamping and turning device (4) and is configured to control the work of the material loading device (2), the detection device (3) and the material clamping and turning device (4).