JP2007230109A - Unevenness inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unevenness inspection device capable of detecting the unevenness of an ink on the outer peripheral blanket for transferring. <P>SOLUTION: In the manufacturing step of a color filter by a printing method, the pattern with ink coating unevenness is formed in the transferred glass substrate if ink coating unevenness is present in a blanket face for transferring the ink. The glass substrate with defects must be sent to a cleaning step. Accordingly, the blanket face before transferring is photographed by a line camera 4, a printing machine is stopped in the case there is unevenness in the blanket face, the step is shifted to a blanket cleaning step or the signal for shifting to the blanket cleaning step is output. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-uniformity inspection apparatus for detecting non-uniformity at the time of coating a rotary drum outer peripheral blanket surface for transfer in a reverse printing type transparent colored film manufacturing process.

A conventional unevenness inspection apparatus, for example, a color inspection machine excluding a color filter BM, inspects after coating ink on a glass substrate (see Patent Document 1).
JP 2004-223437 A

  Therefore, in the conventional unevenness inspection apparatus, in the case of reversal printing, there is a problem that when unevenness of ink occurs in the plate before coating, similar unevenness is formed on the transferred glass substrate.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a non-uniformity inspection apparatus capable of detecting the presence or absence of non-uniformity of ink on a drum outer blanket to be transferred.

  In order to achieve the above object, the unevenness inspection apparatus of the present invention is an unevenness inspection apparatus for detecting unevenness of ink coating on the outer peripheral blanket surface of a transfer rotary drum during the production of a reverse printing method transparent colored film, Obtained by illuminating the rotary drum outer blanket surface with uniform light, an imaging device for imaging the transfer rotary drum outer blanket surface, and imaging the transfer rotary drum outer blanket surface with the imaging device. And a determination unit that determines unevenness of ink coating on the outer peripheral blanket surface of the transfer rotary drum based on the image data obtained.

  According to the unevenness inspection apparatus of the present invention, it is possible to provide an unevenness inspection apparatus that can detect the presence or absence of ink unevenness on the drum outer peripheral blanket to be transferred and can improve the yield during the production of the transparent colored film.

In the present embodiment, in the printing type color filter manufacturing process, when there is ink coating unevenness on the ink transfer blanket surface, a pattern having ink coating unevenness is also formed on the transferred glass substrate. A defective glass substrate must be sent to the cleaning process. For this reason, image the blanket surface before transfer with a line camera, and if there is uneven ink coating on the blanket surface, stop the printing press and move to the blanket cleaning process, or a signal to shift to the blanket cleaning process Output.
FIG. 1 is a perspective view showing an outline of a printing method color filter coating apparatus and an inspection apparatus for explaining the unevenness inspection apparatus of the present embodiment.
A blanket 2 is wound around the outer periphery of the rotating drum 1, and ink is uniformly applied to the surface of the blanket 2 by ejecting ink from the nozzles to the rotating rotating drum 1.

  When the ink is uniformly applied on the surface of the blanket 2, the rotary drum 1 moves from the rotation reference position to the transfer reference position and is transferred to the glass substrate 3 under various conditions.

  After the rotary drum 1 rotates and ink coating is started on the surface of the blanket 2, the ink coating start point is converted into a rotation angle based on the signal read from the encoder of the rotary drum 1, and imaging is started by the line camera 4. To do.

  The light source uses a three-wavelength straight tube fluorescent lamp 5 and irradiates the coated surface with uniform light. A band pass filter 6 having the same color as the ink to be coated is attached to the front surface of the line camera 4, and the light that has passed through the band pass filter 6 is acquired.

  In the case of specular reflection illumination, all the RGB light is reflected by the specularly reflected light on the ink surface, but the same color as the ink is obtained as the surface reflected light because the band pass filter 6 of the same color as the ink is interposed. Will be. Then, the surface reflected light and the light that passes through the ink and is regularly reflected on the surface of the blanket 2 and interferes again with the ink, and the ink unevenness is emphasized.

  In the case of dark field illumination, light is not reflected from the ink surface and does not return from the ink surface, but the light passing through the ink is imaged again from the scattered light generated through the ink and passing through the ink under the blanket. . In this case, an image similar to that obtained by seeing the glass substrate after the transfer visually observed can be obtained.

Data acquired by the line camera 4 is transferred to the image analysis / defect determination device 7 and analyzed. As a result, two-dimensional array data as shown in FIG. 2 is obtained.
FIG. 2 is a diagram illustrating an example of two-dimensional array data obtained based on data acquired by the line camera 4. In the figure, reference numeral 8 indicates streaky ink coating unevenness.
This is passed through an averaging filter or a primary filter of a median filter, the luminance value is added in the vertical direction, and divided by the number of vertical pixels to obtain horizontal one-dimensional array data of average luminance, for example, a waveform indicated by reference numeral 9 in FIG. As a data waveform obtained by taking a moving average in a frequency band different from the unevenness, a difference value from the waveform indicated by reference numeral 10 in the figure is obtained. If this is the waveform indicated by reference numeral 11 in FIG. 4, if the peak value of this waveform exceeds the threshold indicated by reference numeral 12, it is determined that there is a defect, that is, ink unevenness.
FIG. 3 is a waveform diagram showing an example of horizontal average one-dimensional array data of the average luminance.
FIG. 4 is a waveform diagram showing an example of the difference value.

  When the defect determination device 7 determines that the defect is present, it immediately outputs a stop signal for rotation or movement of the rotary drum 1 to stop the printing press. Further, a signal for transferring to the blanket 2 cleaning process is output to clean the surface of the blanket 2 manually or automatically.

As described above, in the reversal printing method to which the unevenness inspection apparatus of the present embodiment is applied, the transfer blanket 2 is wound around the rotary drum 1, and ink is uniformly applied to the surface of the blanket 2. Under the conditions, the drum moves and is transferred to a glass substrate to form a color filter.
Further, before coating on the glass substrate, the presence or absence of ink unevenness is inspected in the outer peripheral blanket surface of the transfer rotary drum.
Moreover, it has a configuration in which a white blanket having diffusibility is wound around the outer periphery of the rotating drum.
In addition, the imaging field of the blanket surface is irradiated with uniform light, transmitted through the ink surface, and diffused light from the blanket 2 is acquired by the line camera 4.
In addition, the three-wavelength straight tube fluorescent lamp has both a light amount distribution of bright lines and uniform light in RGB. In the case of meta-harassment other than fluorescent lamps, irradiation is performed through an optical fiber and through a diffusion plate. An optical filter such as a band pass filter or a dichroic filter that irradiates the inspection surface and transmits only the wavelength band of the ink transmitting region is attached to the front surface of the lens of the line camera 4, and ink transmitted light due to scattered light from the blanket surface is attached. It is the nonuniformity inspection apparatus to acquire.
Further, the imaging field of view of the blanket surface is irradiated with uniform light, transmitted through the ink surface, and transmitted light from the base white blanket and reflected light from the ink surface are acquired by the line camera 4.
In addition, the three-wavelength straight tube fluorescent lamp has both a light amount distribution of bright lines and uniform light in RGB. In addition, in the case of meta-harassment other than fluorescent lamps, irradiation is performed through an optical fiber and through a diffusion plate. An optical filter such as a band-pass filter or a dichroic filter that irradiates the inspection surface and transmits only the wavelength band of the ink-transmitting region is attached to the front surface of the lens of the line camera 4, transmits the ink surface, and starts from the base white blanket surface. Is a non-uniformity inspection apparatus that acquires the transmitted light of the ink and the reflected light of the ink surface.

In addition, the image obtained from the diffused light from the base white blanket that has passed through the ink surface or the transmitted light from the base white blanket that has passed through the ink surface and the ink when the imaging field of the blanket surface is irradiated with uniform light. The image obtained from the reflected light from the surface is projected in the vertical direction of the image to make one-dimensional array data, and if the difference from the moving average exceeds the threshold, it is regarded as a defect. is there.
Further, a non-uniformity inspection apparatus that acquires ink transmitted light by scattered light from a blanket surface, a non-uniformity inspection apparatus that transmits the ink surface and acquires transmitted light from the base white blanket surface and reflected light from the ink surface, When it is determined that there is unevenness, the rotating drum is immediately stopped and a function for shifting to the cleaning process or a function for outputting a signal for shifting to the cleaning process is provided.

  As described above, according to the present embodiment, it is possible to detect the presence or absence of ink unevenness on the drum outer blanket before the transfer to the glass substrate, that is, before the transfer, and the yield at the time of manufacturing the color filter. There is an effect that it is possible to provide a non-uniformity inspection apparatus capable of improving the above.

It is a perspective view which shows the outline | summary of the printing system color filter coating apparatus and inspection apparatus for demonstrating the nonuniformity inspection apparatus of this Embodiment. It is a figure which shows an example of the two-dimensional arrangement | sequence data obtained based on the data acquired with the line camera in the nonuniformity inspection apparatus of this Embodiment. It is a wave form diagram which shows an example of the horizontal direction one-dimensional array data of the average luminance in the nonuniformity inspection apparatus of this Embodiment. It is a wave form diagram which shows an example of the difference value in the nonuniformity inspection apparatus of this Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rotary drum, 2 ... Blanket, 3 ... Glass substrate, 4 ... Line camera (imaging device), 5 ... Straight tube type fluorescent lamp (illumination part), 6 ... Band pass filter, 7 ... Defect determination device (determination unit).

Claims (7)

A non-uniformity inspection device for detecting non-uniformity of ink coating on the outer peripheral blanket surface of a transfer rotary drum during the production of a reverse printing method transparent colored film,
An illumination unit that emits uniform light to the transfer drum outer peripheral blanket surface;
An imaging device for imaging the outer peripheral blanket surface of the transfer rotary drum;
Based on image data obtained by imaging the transfer rotary drum outer blanket surface by the imaging device, a determination unit that determines ink coating unevenness of the transfer rotary drum outer blanket surface;
An unevenness inspection apparatus characterized by comprising:   The inspection apparatus according to claim 1, wherein the transfer rotary drum outer peripheral blanket has diffusibility with respect to the uniform light irradiated from the illumination unit.   The unevenness inspection apparatus according to claim 2, wherein the imaging apparatus captures an image with dark field illumination.   The unevenness inspection apparatus according to claim 2, wherein the imaging apparatus captures an image with specular reflection illumination.   5. The unevenness according to claim 3, further comprising: a light source that emits light including at least a wavelength band of the same color as the ink; and a filter that transmits only the wavelength band of the irradiated light that transmits the ink. Inspection device.   The determination unit projects an image in a vertical direction with respect to an image obtained by imaging with dark field illumination or specular reflection illumination, and regards it as a defect when a difference from a moving average exceeds a threshold value. The unevenness inspection apparatus according to claim 3, 4 or 5.   7. The unevenness according to claim 6, further comprising a function of stopping the printing press immediately after the determination unit regards as a defect or before transfer, a function of shifting to a blanket cleaning process, or a function of outputting a signal of shifting. Inspection device.

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