TWI518404B - Liquid crystal panel inspection apparatus - Google Patents

Description

LCD panel inspection device

The present invention relates to a liquid crystal panel inspection apparatus which performs photographing by an image pickup apparatus and illuminates a liquid crystal panel in a state in which a polarizing plate is not assembled by a backlight, and determines a defect address of the liquid crystal panel from the image thereof (defect address) ).

In such an inspection apparatus, there is an inspection apparatus described in Patent Document 1. As shown in Fig. 7, the conventional inspection apparatus includes a non-lighting inspection unit A and a lighting inspection unit B. In the non-lighting inspection unit A, the liquid crystal panel 1 in which the polarizing plate is not mounted is inspected in a state where the voltage is not applied to each of the pixels of the liquid crystal panel 1 (not driven). Further, in the lighting inspection unit B, the liquid crystal panel 1 is inspected in a state in which the respective pixels pass through the probe unit 2 with a voltage applied thereto (driving).

In the non-lighting inspection unit A, a pair of polarizing plates 4a and 4b are disposed above and below the liquid crystal panel 1 on the table 3. The backlight source 5 irradiates the lower surface 1b of the liquid crystal panel 1 with light at a right angle to the lower surface 1b through the lower polarizing plate 4b. In the table 3, the mirror 6 is held vertically, so that a part of the light from the backlight source 5 is reversed by the mirror 6. The light is directed toward the periphery of the liquid crystal panel 1, whereby the amount of light in the peripheral portion of the liquid crystal panel 1 is increased.

The liquid crystal panel 1 receives the light of the backlight source 5, passes through the upper polarizing plate 4a, and photographs the upper surface 1a by the imaging device 7. The pair of polarizing plates 4a and 4b are arranged such that the polarization directions are parallel to each other. Further, the light that penetrates the liquid crystal panel 1 in the non-lighting state is rotated by a phase of 90 degrees between penetrations. Therefore, unless there is a scattering factor in the optical path passing through the liquid crystal panel 1, the light traveling through the backlight source 5 of the liquid crystal panel 1 is blocked by the polarizing plate 4a. As a result, the light from the backlight source 5 is not captured by the image pickup device 7, but a black screen can be obtained by the image pickup device 7. However, when the liquid crystal panel 1 has flaws or foreign matter adheres to the surfaces 1a and 1b of the liquid crystal panel 1, the strong light from the backlight source 5 is scattered due to flaws and/or foreign matter. Since a part of the scattered light penetrates the polarizing plate 4a, the above-mentioned flaws and/or foreign matter are observed as bright spots on the black screen by the image pickup device 7.

The foreign matter adhering to the surfaces 1a and 1b of the liquid crystal panel 1 can be removed by, for example, cleaning. Therefore, it is necessary to remove the bright spots generated by the foreign matter from the object to be considered. Therefore, the liquid crystal panel 1 next receives the non-lighting inspection using the oblique illumination light source 8 in the same non-lighting inspection unit A. In this non-lighting inspection, the oblique illumination light source 8 assembled to the table 3 is lit up instead of the backlight source 5. Further, the mirror 6 is housed in a horizontal storage position which is displayed by a broken line in the non-lighting inspection portion A of Fig. 7 so as not to obstruct the light from the oblique illumination light source 8. The liquid crystal panel 1 on the stage 3 is received not from the polarizing plate 4b but from the lower surface 1b. Oblique illumination from oblique illumination source 8. The obliquely irradiated light does not directly reach the mirror 6, and is scattered by foreign matter adhering to the surfaces 1a, 1b of the liquid crystal panel 1. However, the oblique illumination light from the oblique illumination source 8 does not receive as strong a scattering as the aforementioned foreign matter depending on the flaws in the liquid crystal panel 1. As a result, under the oblique illumination light source 8, in the black screen of the surface 1a of the liquid crystal panel 1 which is photographed by the image pickup device 7 through the polarizing plate 4a, the bright spots due to the foreign matter and the defects caused by the aforementioned flaws are generated. The difference in brightness of the bright spots, that is, the bright spots caused by the foreign matter and the bright spots caused by the aforementioned flaws can be discerned.

Therefore, it is possible to judge either of the highlight data obtained by the non-lighting inspection unit A under the backlight source 5 and the highlight data obtained by the non-lighting inspection unit A under the oblique illumination source 8. Whether the highlight is the highlight of the real 瑕疵 (画素瑕疵).

However, in the two inspections using the non-lighting inspection unit A described above, in order to display a bright spot on a black screen, it is not possible to quickly determine a pixel address that is determined to belong to a bright spot generated by the latter, that is, it cannot be quickly determined. The correct pixel address.

Therefore, in order to obtain the pixel address which is determined to be a bright spot of the 瑕疵 in the two inspections of the non-lighting inspection unit A, the liquid crystal panel 1 is applied to the transmissive probe unit 2 by the lighting inspection unit B. The voltage is checked (driven) and checked. In the lighting inspection unit B, the liquid crystal panel 1 passes through the polarizing plate 4b similar to the polarizing plate 4b, and receives the light from the backlight source 5', and passes through the polarizing plate 4a' similar to the polarizing plate 4a. The imaging device 7' performs imaging. With the photography, the foregoing The black and white matter is extracted as a black dot on the lighting screen of the liquid crystal panel 1, and a black matrix for defining each pixel is extracted from the lighting screen. Therefore, the address of the black dot corresponding to the bright spot generated by the aforementioned chirp can be easily read from the photographing screen of the image pickup apparatus 7', whereby the real pixel address can be easily known.

As a result, the 瑕疵 瑕疵 。 can be properly repaired according to the 画 画 画 。 。 。.

However, in the above-described liquid crystal panel inspection apparatus, the installation space of the apparatus constituting each inspection unit is required for each of the non-lighting inspection unit A and the lighting inspection unit B, and the footprint is enlarged. . In addition, it is necessary to transfer the liquid crystal panel 1 between the two inspection units A and B, and in order to make the bright spot obtained by the non-lighting inspection unit A and the black point obtained by the lighting inspection unit B correspond to each other, the liquid crystal panel 1 must be performed. The correct configuration is not conducive to shortening the tact time.

(previous technical literature)

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2008-40201

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a liquid crystal panel inspection apparatus which eliminates the aforementioned disadvantages, and simplifies, quickly and correctly specifies the address of a liquid crystal panel.

In order to solve the problem of the known floor space and prevent liquid crystal When the panel is transferred between the two inspection units A and B, it is conceivable to assemble the probe unit 2 of the lighting inspection unit B to the non-lighting inspection unit A. However, even if only the probe unit 2 of the lighting inspection unit B is assembled to the non-lighting inspection unit A, the oblique oblique illumination from the oblique illumination light source 8 cannot sufficiently reach the oblique illumination light to the liquid crystal panel 1 The side where the side of the oblique illumination light source is disposed is the peripheral portion on the opposite side, and the appropriate illumination light is lacking in the peripheral portion of the liquid crystal panel 1. This insufficient oblique illumination light is an obstacle to the rapid and easy judgment of the bright spot by the non-lighting inspection unit A under the oblique illumination light source 8.

Therefore, in the non-lighting inspection under the light of the oblique illumination source, the present invention is basically characterized in that a reflection means is provided in the table in order to enhance the oblique illumination light in the peripheral portion of the liquid crystal panel. The means for directing oblique illumination light from the oblique illumination source to the liquid crystal panel at a suitable incident angle without passing through a polarizing plate disposed below the liquid crystal panel, and directing a portion of the oblique illumination light to the liquid crystal panel The peripheral part of the surface.

That is, the present invention is a liquid crystal panel inspection apparatus for inspecting a liquid crystal panel without a polarizing plate, comprising: a lifting platform; a table disposed on the lifting platform and having an opening having an overall rectangular shape a frame body that receives the edge of the liquid crystal panel by the frame body in order to hold the liquid crystal panel above the lifting platform; and the first and second polarizing plates are disposed above and below the liquid crystal panel on the table. And maintaining the polarization direction in a predetermined relationship with each other; the backlight unit is substantially straight from the lower surface of the liquid crystal panel and the lower surface by the second polarizing plate The illuminating light of the corner illuminates the liquid crystal panel on the working table; the illuminating light source is configured to illuminate the liquid crystal panel on the working table in an angular direction from below the lower surface; the probe unit is raised in the lifting platform Positioning a lighting check of the liquid crystal panel to apply a voltage to a pixel of the liquid crystal panel; and an image pickup device for selectively receiving the oblique light from the backlight unit and the oblique light from the oblique illumination source In the state of any of the illumination light, the upper surface of the liquid crystal panel is imaged by the first polarizing plate; and the reflecting means is disposed in the table so that the oblique illumination light from the oblique illumination source does not pass through The second polarizing plate is guided to the liquid crystal panel at an appropriate incident angle, and guides one of the obliquely irradiated lights to a peripheral portion of the lower surface of the liquid crystal panel.

According to the liquid crystal panel inspection apparatus of the present invention, the non-lighting inspection can be performed under the illumination light from the backlight unit provided on the single lifting platform, and the non-pointing can be performed under the oblique illumination light source instead of the illumination light from the backlight. The light inspection is performed, and the lighting inspection using the aforementioned probe unit is performed under the illumination light from the backlight unit. Therefore, it is not necessary to transfer the liquid crystal panel from the non-lighting inspection unit A to the lighting inspection unit B as in the prior art, that is, it is possible to quickly perform a series of inspections, and it is not necessary to perform the alignment between the two inspection units A and B. . Therefore, the inspection can be quickly performed with a simplified device configuration, and the production time can be shortened.

Further, in the non-lighting inspection under the oblique illumination light source, the reflection means is configured such that the oblique illumination light from the oblique illumination source is incident on the liquid crystal at an appropriate incident angle without passing through the second polarizing plate. In the manner of a panel, one of the aforementioned oblique illumination lights is guided to the lower surface of the liquid crystal panel. Therefore, in the non-lighting inspection under the light of the oblique illumination source, the amount of oblique illumination light in the peripheral portion of the liquid crystal panel does not occur. Therefore, it is possible to solve the problem of the rapid and easy judgment of the bright spot by the non-lighting inspection under the light of the oblique illumination source by the adverse effect caused by the insufficient amount of light.

In order to enable uniform oblique illumination of the lower surface of the liquid crystal panel corresponding to the size of the liquid crystal panel, the reflection means may be rotatably supported around the axis supported by the table, in addition to The aforementioned reflecting means can be maintained at an appropriate angle by means of an actuating means for rotating about the aforementioned axis.

In the reflection means, the angle is adjusted by the actuator, and the incident angle incident on the lower surface of the liquid crystal panel by the reflection means is set to 60 degrees or more and less than 90 degrees.

The shaft system of the reflecting means can be disposed along one side of a pair of sides facing the opening of the rectangular opening of the table, and the oblique illumination source can be along the pair of sides The other side is stretched and arranged. The reflection means and the oblique illumination source are disposed on each of four sides of the rectangular opening portion so as to be paired with each other.

The reflection means may be constituted by a mirror supported by the stage via a horizontal axis on the upper edge. In this case, the actuating device is operatively coupled to the mirror in order to maintain the mirror at a desired erect angle.

The actuating device may include any one of a ball screw mechanism including a bolt member rotatable by an electric motor and a nut member screwed to the bolt member.

The oblique illumination light source can be supported by the lifting platform such that its height position is higher than the height position of the second polarizing plate. Further, the oblique illumination light source may be supported by the lifting platform via a base for the backlight of the lifting platform on the lifting platform.

The aforementioned table can be held by the spacer members and spaced apart from the lifting platform. In this case, the oblique illumination source may be disposed in a space between the table defined by the spacer member and the lifting platform.

The frame system of the table can adjust the size of each side of the opening to a liquid crystal panel suitable for different sizes. The frame system as described above can be realized, for example, by being assembled in a shape of a well in such a manner that it can move in parallel to each member.

In order to replace the frame that can be adjusted as described above, the table can be detachably supported on the lifting platform so that the table can be replaced with a work suitable for the opening of the liquid crystal panel. station.

When a table that can adjust the opening according to the size of the liquid crystal panel or a table that is provided with the opening suitable for the opening of the liquid crystal panel is used, it is preferable to combine the following configurations: The aforementioned reflecting means is wound around the axis supported by the aforementioned workbench The manner is rotatably supported, and the aforementioned reflecting means is maintained at an appropriate angle by means of an actuating means for rotating about the aforementioned axis. This is because the liquid crystal panel can be uniformly irradiated with oblique illumination light within a suitable incident angle range regardless of the size of the liquid crystal panel.

According to the present invention, since the liquid crystal panel can be transferred between the two inspection units without being transferred between the two inspection units, it is possible to simplify the inspection apparatus and to shorten the production time. Moreover, since the non-lighting inspection under the light of the oblique illumination source can perform the quick and easy judgment operation of the bright spot, the production time can be further shortened.

1,12,12'‧‧‧ LCD panel

1a, 1b‧‧‧ surface

2, 40‧‧‧ probe unit

3, 16, 16' ‧ ‧ workbench

5, 5'‧‧‧ Backlight source

6‧‧ ‧ mirror

7, 7'‧‧‧ camera

8, 32‧‧‧ oblique lighting source

10‧‧‧LCD panel inspection device

12a, 12a'‧‧‧ upper surface of the LCD panel

12b, 12b'‧‧‧ LCD panel lower surface

14‧‧‧ Lifting platform

18‧‧‧Photography

18a‧‧‧ camera

20‧‧‧Backlight unit

20a‧‧‧Light radiation surface

20b‧‧‧ unit base

22a, 22b, 4a, 4b, 4a'‧‧‧ polarizing plates

24‧‧‧Light diffuser

26‧‧‧ spacers

28‧‧‧ frame

28a, 28a'‧‧‧ openings

30‧‧‧ Space

32a‧‧‧ bracket

34‧‧‧Reflex means

34a‧‧‧reflecting surface

36‧‧‧Axis

38‧‧‧Acoustic device

38'‧‧‧ actuation device

40a‧‧‧Probe

42‧‧‧Image processing device

44a, 44b, 44c, 44d‧‧‧ Highlights

46‧‧‧Black matrix

A‧‧‧Non-lighting inspection department

B‧‧‧Lighting inspection department

Fig. 1 is a cross-sectional view schematically showing a liquid crystal panel inspection device of the present invention.

Fig. 2 is a cross-sectional view showing a liquid crystal panel inspection apparatus which is in a non-lighting (non-driving) inspection step under backlight light.

Figure 3 is a cross-sectional view showing a liquid crystal panel inspection apparatus in a non-lighting (non-driving) inspection step under oblique illumination source light.

Fig. 4 is a cross-sectional view showing a liquid crystal panel inspection apparatus which is in a lighting (driving) inspection step under backlight light.

Fig. 5 is a view showing an imaging screen obtained by an imaging device in each inspection step, and Fig. 5(a) is a non-lighting (non-driving) inspection step under backlight light source shown in Fig. 2; Acquired camera image, Figure 5 (b) The image obtained by the non-lighting (non-driving) inspection step under the oblique illumination source light shown in Fig. 3, and Fig. 5(c) is the backlight shown in Fig. 4. The image of the camera obtained by the lighting (drive) inspection step under the light source.

Fig. 6 is a cross-sectional view similar to Fig. 3 showing another example of the liquid crystal panel inspection device of the present invention.

Fig. 7 is a cross-sectional view showing a conventional liquid crystal panel inspection device.

The liquid crystal panel inspection device 10 of the present invention is used for inspection of the liquid crystal panel 12 having no pair of polarizing plates. The liquid crystal panel 12 has a rectangular planar shape, and conventionally known electrodes for applying a driving voltage to each pixel of the liquid crystal panel 12 are arranged on each side of the surface (upper surface) 12a of one of the liquid crystal panels 12 (not shown). Show).

The liquid crystal panel inspection apparatus 10 includes an elevating table 14 that can be moved up and down in a vertical direction (z-axis direction) that belongs to the vertical direction in the first drawing, and is supported by the elevating table and is used to hold the object to be inspected. A table 16 of the liquid crystal panel 12; and an imaging means 18 such as a CCD camera capable of photographing the upper surface 12a of the liquid crystal panel 12 held on the table from above the table 16.

The elevating table 14 is movable, for example, in the x and y directions of the xy plane at right angles to the z-axis, and may be configured by an xyzθ stage that is rotatable about the z-axis. On the elevating table 14, a conventionally known backlight unit 20 is disposed so as to be positioned substantially directly below the liquid crystal panel 12 held on the table 16. The backlight unit 20 is configured to have its light emitting surface The 20a is attached to the elevating table 14 by the unit base 20b so as to be substantially parallel to the lower surface 12b of the liquid crystal panel 12 held on the table 16.

Between the imaging device 18 and the backlight unit 20, the first and second polarizing plates 22a and 22b are disposed above and below the liquid crystal panel 12, respectively. In the illustrated example, three cameras 18a, 18a, and 18a are used as the imaging means 18, and each of the cameras 18a is arranged such that the field of photography is slightly repeated. Further, the three first polarizing plates 22a are arranged corresponding to the respective cameras 18a. Instead, a single first polarizing plate 22a can be used to cover the imaging area of each camera 18a.

The second polarizing plate 22b is disposed on the light emitting surface 20a of the backlight unit 20 via the light diffusing plate 24 for achieving uniform light intensity. The first polarizing plate 22a and the second polarizing plate 22b are held such that their polarization directions are parallel to each other.

The table 16 holding the liquid crystal panel 12 is provided with a frame body 28 having a rectangular portion as a whole, and the side portions are held by the spacers 26 and spaced apart from the lifting table upwards on the lifting table 14, and Arranged along each side of the rectangular liquid crystal panel 12. The frame body 28 has a rectangular opening portion 28a, and each side portion of the frame body 28 receives the respective side portions corresponding to the liquid crystal panel 12. The light from the backlight unit 20 passing through the light diffusing plate 24 and the second polarizing plate 22b passes through the opening 28a of the table 16, and can be irradiated at an angle substantially at right angles to the lower surface 12b of the liquid crystal panel 12. Lower surface 12b.

Keeped on the table 16 and lifted by the spacer 26 The space 30 between the stages 14 is provided with, for example, four linear oblique illumination sources 32. Two of the four oblique illumination sources 32 are shown opposite each other in FIG. Each of the oblique illumination light sources 32 is disposed so as to extend substantially parallel to each side corresponding to the liquid crystal panel 12 and to surround the light emission surface 20a of the backlight unit 20. Further, each of the oblique illumination light sources 32 is held below the outer region of the liquid crystal panel 12 and higher than the height position of the second polarizing plate 22b, and is held by the unit base 20b of the backlight unit 20 by the bracket 32a. The tilting illumination source 32 can be directly supported on the lifting platform 14 instead of being supported on the unit substrate 20b.

On the inner side of the table 16, that is, on the side of the opening 28a of the casing 28, for example, a reflecting means 34 for reflecting the mirror is disposed along the side portion corresponding to the frame 28, and the reflecting means 34 is arranged such that The reflecting surface 34a is directed toward the center of the opening portion 28a. Each of the reflecting means 34 is rotatably supported on the table 16 by the upper edge by being disposed substantially horizontally and supported on the shaft 36 of the table 16. Further, an actuating device 38 for rotating each of the reflecting means 34 about the shaft 36 is provided on the table 16.

Each actuating device 38 is operatively coupled to the lower edge of the corresponding reflecting means 34 in order to adjust the erection angle θ of the reflecting means 34 belonging to the narrowing angle of the reflecting surface 34a and the horizontal plane and to maintain the desired set angle. As described above, the actuating means 38 may include an electric motor (not shown), a bolt member rotatable by the electric motor, and a nut member screwed to the bolt member. A conventional ball screw mechanism or a linear motor has been known.

The actuating device 38 sets the respective erecting angles θ to less than 90 degrees, whereby the reflecting means 34 disposed on one of the sides corresponding to the opening 28a as described later are respectively directed toward the lower surface of the liquid crystal panel 12. The incident angle of 12b is an appropriate angle, and the oblique illumination light from the oblique illumination light source 32 disposed along the opposite side is guided to the lower surface 12b.

In the example shown in Fig. 1, in order to replace the table 16 having the opening 28a corresponding to the size of the liquid crystal panel 12, the table 16 is detachable from a bolt nut assembly (not shown). The spacer 26 is detachably coupled to the clamp mechanism or the like.

In the first drawing, the table 16 is shown in a solid line, and the table 16 has an opening portion 28a suitable for the size of the liquid crystal panel 12 shown by a solid line, and the table 16' is displayed by a virtual line. The stage 16' has an opening portion 28a' suitable for the size of the liquid crystal panel 12', and the liquid crystal panel 12' has a size smaller than that of the liquid crystal panel 12 shown by a solid line.

In place of the size of the liquid crystal panel 12, the whole of the table 16 is replaced by the above-described table 16'. For example, as disclosed in Japanese Laid-Open Patent Publication No. 2007-163426, four can be moved in parallel. The frame member 28 having the adjustable opening portion 28a can be formed by combining the side members in a shape of a well or a letter.

Above the table 16, a conventionally known probe unit 40 is disposed to drive the liquid crystal panel in order to perform lighting inspection of the liquid crystal panel 12 on the table. The probe unit 40 is attached to the lifting platform The rising position of 14 causes the corresponding probe 40a to contact the aforementioned electrode of the liquid crystal panel 12.

The imaging means 18 is set to be fixed to the liquid crystal panel 12 at the time of inspection of the liquid crystal panel 12. The image data obtained by each imaging device 18 is transmitted to a conventionally known image processing device 42.

Hereinafter, the procedure for inspecting the liquid crystal panel 12 using the liquid crystal panel inspection device 10 will be described.

[Non-lighting check under backlight illumination]

In the non-lighting inspection under backlight illumination, the oblique illumination source 32 is in an extinguished state, and the backlight unit 20 is turned on, that is, the backlight source is turned on. Further, as shown in Fig. 2, the probes 40a of the probe unit 40 are in a state of not contacting the electrodes of the liquid crystal panel 12, so that the liquid crystal panel 12 is in a non-lighting (non-driving) state.

In the non-lighting state, the light emitted from the light emitting surface 20a of the backlight unit 20 is transmitted through the second polarizing plate 22b by the light diffusing plate 24 while being appropriately dispersed. The light from the backlight unit 20 is converted into polarized light by passing through the second polarizing plate 22b, and the polarized light is incident on the liquid crystal panel 12 at a substantially right angle. Since the liquid crystal panel 12 is in a non-driving state, the polarized light is rotated by 90 degrees on its polarizing surface by the penetration of the liquid crystal panel 12. The polarized light that is rotated by 90 degrees on the polarizing surface is blocked by the first polarizing plate 22a.

As a result, the image of the liquid crystal panel 12 passing through the first polarizing plate 22a is not captured by the respective cameras 18a, except for the liquid crystal. A foreign object is attached to the upper surface 12a or the lower surface 12b of the panel 12, or a pixel of the liquid crystal panel 12 is present, otherwise it is photographed by each camera 18a, and the data is processed by the image processing device 42 to obtain the obtained liquid crystal panel 12. The photographic screen should be observed as a black screen. However, when foreign matter adheres to the upper surface 12a and/or the lower surface 12b of the liquid crystal panel 12, or if there is a foreign matter inside the pixel of the liquid crystal panel 12, the foreign matter is a cause of scattering of the polarized light, and the scattered light passes through the first The polarizing plate 22a is picked up by the imaging means 18 as a bright spot.

The polarized light obtained by the light from the backlight unit 20 passing through the light diffusing plate 24 and the second polarizing plate 22b is substantially not opposed to the liquid crystal by the reflecting surface 34a which is maintained at an angle of erecting at an angle θ of a right angle. The peripheral portion of the panel 12.

Fig. 5(a) shows an example of bright spots distributed on the aforementioned black screen obtained by the image processing device 42. In the example shown in Fig. 5(a), four bright spots 44a, 44b, 44c, and 44d are observed.

It is necessary to discriminate whether or not any of the four bright spots 44a, 44b, 44c, 44d belongs to a foreign matter attached to the upper surface 12a and/or the lower surface 12b of the liquid crystal panel 12 by a non-pixel, or whether It is produced by foreign matter inside the pixel of the liquid crystal panel 12 which is regarded as a picture. In order to determine the bright spots caused by the adhesion of the foreign matter and the bright spots generated by the pixels, the non-lighting inspection under the oblique illumination source light described below is performed.

[Non-lighting check under oblique illumination source light]

In the non-lighting inspection under the oblique illumination source, the lighting is tilted The backlight unit 20 is replaced by an oblique illumination source 32, and the backlight unit 20 is in an extinguished state. Further, as shown in FIG. 3, since the probes 40a of the probe unit 40 are in a non-contact state with the electrodes of the liquid crystal panel 12, the liquid crystal panel 12 is in a non-lighting (non-driving) state.

The light from the oblique illumination source 32 does not pass through the light diffusion plate 24 and the second polarizing plate 22b, but is irradiated obliquely upward toward the lower surface 12b of the liquid crystal panel 12 on the table 16. Although the oblique illumination light source 32 is disposed along each side of the liquid crystal panel 12, it is difficult to sufficiently reach the light system from the oblique illumination source in the vicinity of the side of the liquid crystal panel 12 corresponding to the oblique illumination source. For example, viewing the oblique light emitted from the oblique illumination light source 32 located on the right side in the figure in FIG. 3 is difficult to directly reach the peripheral portion on the right side in the figure of the liquid crystal panel 12. Similarly, it is difficult to directly reach the peripheral portion on the left side in the drawing of the liquid crystal panel 12 from the oblique light radiated from the oblique illumination light source 32 located on the left side in the drawing.

However, in the liquid crystal panel inspection apparatus 10 of the present invention, a reflection means 34 is provided for adjusting the erection angle θ to an appropriate angle by the actuation means 38, the actuating means 38 being rotatably rotated by the shaft 36 Support at workbench 16. Therefore, for example, a portion of the oblique light radiated from the oblique illumination light source 32 provided on the right side of the third figure is directed by the reflection surface 34a of the reflection means 34 provided on the left side of the third figure on the opposite side. The peripheral portion on the right side in the lower surface 12b of the liquid crystal panel 12 is guided at an incident angle of α degrees. Similarly, a part of the oblique light radiated from the oblique illumination light source 32 provided on the left side of the third figure is oriented toward the reflection surface 34a of the reflection means 34 on the opposite side. The peripheral portion on the left side in the lower surface 12b of the liquid crystal panel 12 is guided at an incident angle of α degrees.

Since the amount of light in each peripheral portion of the liquid crystal panel 12 is increased by the reflected light on the reflecting surface 34a of the reflecting means 34, the amount of light in the peripheral portion is insufficient. The aforementioned erection angle θ of the reflecting means 34 can be adjusted to an appropriate angle of less than 90 degrees, so that the incident angle α to the reflecting surface 34a becomes 60 degrees or more and less than 90 degrees.

The oblique illuminating light from the oblique illuminating light source 32 does not pass through the first polarizing plate 22a and reaches the imaging means 18 unless it is scattered. However, when a foreign matter adheres to the upper surface 12a or the lower surface 12b of the liquid crystal panel 12, a part of the scattered light of the foreign matter is drawn to the imaging means 18 via the first polarizing plate 22a. Further, even if the ruthenium in the liquid crystal panel 12 is scattered, it does not receive scattering as strong as the foreign matter described above. As a result, under the oblique illuminating light of the oblique illuminating light source 32, the black screen of the upper surface 12a of the liquid crystal panel 12 photographed by the first polarizing plate 22a by the imaging means 18 is as shown in Fig. 5(b). Four bright spots 44a, 44b, 44c, and 44d are observed at the same position as shown in Fig. 5(a). However, since a bright luminance difference between the bright spot generated by the foreign object and the bright spot generated by the foregoing defect is generated, the image processing device 42 sets the appropriate threshold value according to the brightness difference of the image processing device. To identify the bright spots caused by foreign objects and the bright spots caused by the pixels. In the illustrated example, the bright spots 44b, 44c, and 44d are generated by foreign matter, and the bright spots 44a having lower brightness of the brighter points 44b, 44c, and 44d are generated by the pixels. Therefore, it can be determined that the bright spot 44a is a pixel belonging to the detection target. defect.

The oblique illuminating light from the oblique illuminating light source 32 is as described above, and the amount of light that is entangled in the peripheral portion of the liquid crystal panel 12 by the reflecting means 34 is insufficient, so that substantially all of the liquid crystal panel 12 is diffused with a desired amount of light. region. Therefore, even if the bright spot generated by the foreign matter or the bright spot generated by the pixel is located at, for example, the peripheral portion of the liquid crystal panel 12, it is possible to easily and surely distinguish the two depending on the difference in luminance between the bright spots.

[Lighting check]

Next, the liquid crystal panel 12 on the stage 16 receives the lighting inspection while driving the respective pixels. As shown in Fig. 4, in the lighting inspection, each probe 40a of the probe unit 40 contacts the corresponding electrode of the liquid crystal panel 12 on the stage 16, and supplies a driving voltage to each pixel. Therefore, the respective pixels of the liquid crystal panel 12 do not rotate the polarizing surface of the light that penetrates the liquid crystal panel 12. Therefore, when the backlight unit 20 is turned on again to replace the oblique illumination light source 32, the light from the backlight unit 20 is converted into uniform polarization by the light diffusion plate 24 and the second polarizing plate 22b, but the liquid crystal panel 12 is driven. Therefore, the polarized light does not rotate the polarizing surface and penetrates the liquid crystal panel 12, and reaches the first polarizing plate 22a. The first polarizing plate 22a allows penetration of the polarized light that does not rotate the polarizing surface. As a result, the image of the liquid crystal panel 12 obtained by the imaging means 18 becomes a lighting screen, that is, when the liquid crystal panel 12 is a black and white panel, a white screen is formed, and when the liquid crystal panel 12 is a color panel, a color matching phase with the filter is formed. Corresponding color picture.

As shown in FIG. 5(c), in the lighting screen, the pixel and foreign matter are extracted as corresponding black dots 44a, 44b, 44c, and 44d, and in the lighting screen. A black matrix 46 that is useful to define each pixel is taken. The black image obtained by the fifth image (a) and the fifth image (b) or the image data thereof determines that the bright spot 44a is the one generated by the pixel, and the black dot 44a on the lighting screen corresponding to the bright spot 44a. The pixel address can be easily obtained from the image of Fig. 5(c) mapped by the black matrix 46 or its image data. Therefore, the pixel address of the black dot 44a of Fig. 5(c) can be easily obtained.

According to the liquid crystal panel inspection apparatus 10 of the present invention, as described above, since all of the above-described inspection steps of the liquid crystal panel 12 can be performed on a single stage 16 of the single liquid crystal panel inspection apparatus 10, it is possible to simplify the inspection apparatus. And can seek to shorten the production time. Further, in the non-lighting inspection under the oblique light using the oblique illumination light source 32, since the sufficient illumination light can be guided to the peripheral portion of the liquid crystal panel 12 by the reflection means 34, even in the peripheral portion of the liquid crystal panel 12, It is also possible to quickly and easily determine the bright spots caused by the foreign matter adhering to the surfaces 12a and 12b of the liquid crystal panel 12 and the bright spots caused by the pixels, so that the production time can be further shortened.

Fig. 6 is a view showing an example of using the table 16', and showing a pattern of non-lighting inspection using the light under the oblique illumination source as in Fig. 3, the table 16' is virtual as shown in Fig. 1. As shown by the line, there is an opening portion 28a' suitable for the size of the liquid crystal panel 12', and the liquid crystal panel 12' has a liquid crystal panel 12 as shown by a solid line in FIG. Small size.

As shown in Fig. 6, in the case of processing the small liquid crystal panel 12', the erection angle θ of the reflecting means 34 is set to be smaller than the former case. The erecting angle θ of the reflecting means 34 is the same as that of the large liquid crystal panel 12 described above, by the operation of the actuating means 38' of the table 16' to the lower surface 12b of the liquid crystal panel 12'. The incident angle α is set to an angle of an appropriate angular range (60 degrees or more and less than 90 degrees), and a sufficient amount of light can be secured in the peripheral portion of the liquid crystal panel 12'.

(industrial availability)

The present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit and scope of the invention. For example, the raising angle θ of the reflecting means can be set to be fixed. In addition, a single camera can be used as the imaging means 18, and the number of cameras can be increased in accordance with the necessary image resolution.

10‧‧‧LCD panel inspection device

12, 12'‧‧‧ LCD panel

12a‧‧‧Top surface of the LCD panel

12b‧‧‧Under the surface of the LCD panel

14‧‧‧ Lifting platform

16, 16'‧‧‧ Workbench

18‧‧‧Photography

18a‧‧‧ camera

20‧‧‧Backlight unit

20a‧‧‧Light radiation surface

20b‧‧‧ unit base

22a, 22b‧‧‧ polarizing plate

24‧‧‧Light diffuser

26‧‧‧ spacers

28‧‧‧ frame

28a, 28a'‧‧‧ openings

30‧‧‧ Space

32‧‧‧Slant illumination source

32a‧‧‧ bracket

34‧‧‧Reflex means

34a‧‧‧reflecting surface

36‧‧‧Axis

38‧‧‧Acoustic device

40‧‧‧ probe unit

40a‧‧‧Probe

42‧‧‧Image processing device

Claims (10)

A liquid crystal panel inspection device for inspecting a liquid crystal panel without a polarizing plate, the liquid crystal panel inspection device comprising: a lifting platform; a table disposed on the lifting platform and having an opening having an overall rectangular shape a frame body that receives the edge of the liquid crystal panel by the frame body in order to hold the liquid crystal panel above the lifting platform; and the first and second polarizing plates are disposed above and below the liquid crystal panel on the table. And maintaining the polarization direction in a predetermined relationship with each other; and the backlight unit illuminates the liquid crystal panel on the stage by irradiation light from the lower surface of the liquid crystal panel and the lower surface of the liquid crystal panel by the second polarizing plate; The illumination light source is configured to illuminate the liquid crystal panel on the worktable in an angular direction from below the lower surface; the probe unit is configured to perform the lighting inspection of the liquid crystal panel at a rising position of the lifting platform a pixel applied to the panel; an imaging device for selectively receiving the aforementioned right angle photo from the backlight unit The upper surface of the liquid crystal panel is imaged by the first polarizing plate in a state of light and oblique oblique light from the oblique illumination light source; and the reflecting means is disposed in the table so as to be from the edge the The oblique illumination light of the oblique illumination light source disposed on the corresponding side of the frame body is incident on the liquid crystal panel at an appropriate incident angle without passing through the second polarizing plate, and guides one of the oblique illumination light to the liquid crystal panel. The peripheral portion of the lower surface of the surface adjacent to the oblique illumination source. The liquid crystal panel inspection apparatus according to claim 1, wherein the reflection means is configured to be capable of performing uniform oblique illumination on a lower surface of the liquid crystal panel corresponding to the size of the liquid crystal panel. The means supported by the shaft of the aforementioned table is rotatably supported, and the reflecting means is maintained at an appropriate angle by means of an actuating means for rotating about the aforementioned axis. The liquid crystal panel inspection apparatus according to the second aspect of the invention, wherein the reflection means adjusts an angle by the actuator, and reflects incident on the lower surface of the liquid crystal panel by reflection by the reflection means. The angle is set to 60 degrees or more and less than 90 degrees. The liquid crystal panel inspection apparatus according to claim 2, wherein the axis of the reflection means is one of a pair of sides facing each other along an opening of the rectangular shape of the table. Arranged while being arranged, the oblique illumination source is arranged to extend along the other side of the pair of sides. The liquid crystal panel inspection apparatus according to claim 4, wherein the reflection means includes a mirror supported by the stage via a horizontal axis on the upper edge, and the actuator is intended to be desired. The aforementioned erect angle maintains the aforementioned mirror and is operatively connected Attached to the aforementioned mirror. The liquid crystal panel inspection apparatus according to claim 5, wherein the actuator includes a bolt member including a bolt member rotatable by the electric motor and a nut member screwed to the bolt member. Any of a mechanism and a linear motor. The liquid crystal panel inspection apparatus according to claim 1, wherein the oblique illumination light source is supported by the elevation platform such that a height position thereof is higher than a height position of the second polarizing plate. The liquid crystal panel inspection apparatus according to claim 7, wherein the table is held by a spacer from the elevating table, and the oblique illumination source is disposed by the spacer. The space between the aforementioned workbench defined by the member and the aforementioned lifting platform. The liquid crystal panel inspection apparatus according to claim 1, wherein the frame system of the table can adjust the size of each side of the opening to be suitable for a liquid crystal panel having a different size. The liquid crystal panel inspection apparatus according to claim 1, wherein the table is detachably supported on the lifting platform, and the table can be replaced with the aforementioned one suitable for the liquid crystal panel. Workbench in the opening.