This application claims the priority benefit of Somers et al., Netherlands Patent Application Serial No. NL 2005498, filed on Oct. 11, 2010, entitled “Display As Well As Method And Apparatus For Manufacturing A Display,” the contents of which are incorporated herein by reference in its entirety, including any references therein.
1. Field of the Invention
The present invention relates to a display. The present invention further relates to a method for manufacturing a display. The present invention further relates to an apparatus for manufacturing a display.
2. Background of the Invention
Multicolor displays are known that have a display effect layer capable of generating a pattern by reflecting, transmitting or emitting light with a broad color spectrum (white) and a color filter layer that is capable of converting said light into colored light. One such display is known from WO2007/063440.
The color filter layer 6 may be implemented in various ways. In the example of
The application of the color filter 6 requires additional manufacturing steps. If these steps are not successful the quality of the product may be low, or the product may even be unsuitable for use. Various causes may result in a failure of the additional manufacturing steps, such as the presence of particles, malfunctioning of the equipment, and/or human errors. There is a need to at least mitigate these disadvantages caused by failure introduced during the additional manufacturing steps.
According to a first aspect of the present invention a display is provided. According to a second aspect of the present invention a method is provided. According to a third aspect of the present invention an apparatus is provided.
The display according to the first aspect of the invention has a removably attached color filter. Accordingly, if it is determined that the display does not comply with the requirements due to a failure introduced during the additional manufacturing steps, it is possible to remove the color filter layer. From the color filter layer removal, a compliant monochrome or black and white display is obtained. Alternatively, a new attempt may be made to apply a color filter layer to the display layer.
The method according to the second aspect of the invention is characterized by removably attaching the color filter layer to the display layer. Accordingly, if after carrying out the additional manufacturing steps it is recognized that the manufactured product does not comply with the requirements for a color display, it is possible to remove the color filter and use the product as a monochrome or a black and white display.
The apparatus according to the third aspect of the invention is characterized by a third unit for removably attaching the color filter layer to the display layer.
Accordingly, if after carrying out the additional manufacturing steps it is recognized that the manufactured product does not comply with the requirements for a color display, it is possible to remove the color filter and use the product as a monochrome or a black and white display.
The wording “removably attached” is understood to mean that the color filter layer can be removed from the display layer without damaging the display layer. Nevertheless the color filter layer should be sufficiently tightly attached to the display layer to prevent a spontaneous release thereof during normal use of the device.
As used herein, a “layer” of a given material includes a region of that material whose thickness is small compared to both its length and width. Examples of layers include sheets, foils, films, laminations, coatings, and so forth. As used herein a layer need not be planar, but can be bent, folded or otherwise contoured, for example, to at least partially envelop another component. As used herein a layer can also include multiple sub-layers. A layer can also consist of a collection of discrete portions such as, for example, a layer of discrete active regions comprising individual pixels.
Accordingly, an embodiment of the method according to the second aspect further comprises a step of testing the display after the step of removably attaching the color filter layer and a step of removing the color filter layer from the display layer if the display does not positively pass this test. The resulting display layer may be used in a monochromatic display, or a new attempt may be made to provide the display layer with a color filter layer. Hence in the method according to the second aspect of the invention, the materials and efforts spent in the previous manufacturing steps are not lost if the test indicates that the color filter layer is not correctly attached to the display layer.
Likewise an apparatus according to the third aspect of the invention comprises:
Alternatively, the fourth and the fifth unit may be provided as a separate apparatus.
Various options are possible to removably apply the color filter layer and to remove the color filter layer in case it is detected that the additional manufacturing steps did not result in an acceptable color display.
According to a first option the color filter layer is removably attached to the display layer by an intermediate adhesion layer having a relatively low adherence to the display layer as compared to the adhesion to the color filter layer. The step of removing the color filter layer from the display layer, if the display does not positively pass this test, is carried out by peeling of the color filter layer from the display layer. Release of the color filter layer with the adhesion layer may be promoted by a temperature increase.
According to a second option the color filter layer comprises a release layer at a surface attached to the display layer. The step of removing the color filter layer from the display layer, if the display does not positively pass this test, is carried out by peeling of the color filter layer from the display layer.
According to a third option the color filter layer is attached to the display layer by means of an intermediate layer that is soluble in a solvent that does not solve the display layer. The step of removing the color filter layer from the display layer, if the display does not positively pass this test, is carried out by selectively solving the intermediate layer in a solvent.
According to a fourth option the color filter layer is soluble in a solvent that does not solve the display layer. The step of removing the color filter layer from the display layer, if the display does not positively pass this test, is carried out by selectively dissolving the color filter layer in a solvent. This is advantageous in that an intermediate layer is superfluous.
An embodiment of the method according to the second aspect of the invention further comprises the step of testing the provided display layer, and the step of removably attaching the color filter layer is only carried out after the provided display layer has positively passed the step of testing. In this way the step of removably attaching the color filter is avoided if it is known beforehand that the manufacturing process will not result in an acceptable display anyhow.
If the method according to the second aspect of the invention is successfully completed, a display according to the first aspect of the invention is obtained that comprises a display layer for displaying an image having at least a luminosity component and a color filter layer releasable attached thereto that comprises a color filter for filtering the image according to a predetermined pattern.
These and other aspects of a display and method for making a display are described in more detail with reference to the drawings wherein:
In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by one skilled in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, and components have not been described in detail so as not to obscure aspects of the present invention.
Embodiments of the invention are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes and sizes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
It will be understood that when an element or layer is referred to as being “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “connected to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
The term “weak adhesion” is understood to mean that the peeling force for releasing the layer 8 from at least one of the color filter layer 6 and the display effect layer 4 is preferably at most 3.2 g/mm at room temperature (20° C.). Nevertheless, the peeling is preferably at least 0.8 g/mm so that a spontaneous separation of the color filter layer 6 from the display effect layer 4 is prevented. Nevertheless, an adhesion layer may be used having a temperature dependent adhesion. For example an adhesion layer may be used having an adhesion decreasing with temperature. In that case the peeling strength at room temperature may be higher than 3.2 g/mm, e.g. 10 g/mm.
In an embodiment the adhesion layer 8 has a relatively low adherence to the display layer 4 as compared to the adhesion to the color filter layer 6. In that case the color filter layer 6 can be removed together with the adhesive layer 8 from the display layer 4. In the illustrative embodiment the adhesive is an EVA adhesive (ethylene vinyl acetate). Other suitable adhesives are (urethane) acrylics.
In a second step S2 a color filter layer comprising a color filter for filtering the image according to a predetermined pattern is provided, as is shown in
In a third step S3 the display layer is tested. During this test it is determined whether the display layer correctly functions. If it is determined that the display layer does not comply with the requirements (NOK) the display layer is rejected in step S4 before attaching the color filter layer, so that the latter can be used for another product.
If it is determined that the display layer does comply with the requirements (OK) then in step S5 the color filter layer is attached removably to the display layer.
As shown in
In a second sub-step S5B, as shown in
In a subsequent step S6, the product so obtained is tested. The test may comprise application of test signals to the display manufactured in steps S1, S2, S3 and S5 and to determine whether the generated color image corresponds to a reference image.
If it is determined in step S6 that the product passes the test (OK), the manufacturing processes for the product, e.g. integration with other components, may be continued if necessary, and the product may be packaged. Alternatively, the so obtained display may be sold as a semi-finished product.
If it is determined in step S6 that the product does not pass the test (NOK), then the color filter layer is removed from the display layer during step S8.
Upon completion of step S8, the malfunctioning color display becomes a well functioning black and white or monochrome display. The so obtained black and white or monochrome display may be further processed during step S9, e.g. by integration of the display with other components and packaging. Alternatively, the so obtained display may be sold as a semi-finished product.
According to yet another alternative step S5 may be repeated, involving application of a new removable intermediate substrate at the display layer and application of a new color filter at the new intermediate substrate.
The apparatus comprises a second unit 120 for providing a color filter layer for filtering the image according to a predetermined pattern
The apparatus comprises a lamination unit 130 for removably attaching the color filter layer 6 to the display layer 4. The lamination unit 130 comprises an applicator 132, for example a printer, for applying an adhesive layer at a surface of the display layer 4 to be provided with the color filter layer and further comprises a pair of lamination rolls 134, 136. In
The apparatus comprises a third unit 140 for testing a quality of the product having the removably attached color filter layer on the display layer. In this embodiment the third unit comprises a camera 142 and a controller 144. The camera 142 provides an image of the product to the controller 144. The controller 144 verifies whether the display layer 4 and the color filter layer 6 are properly aligned, for example by determining a relative position of alignment marks present in the display layer and the color filter layer. In a further test a yield is determined. For example it may be determined whether color elements in the color filter layer are missing or incomplete. If the display layer 4 and the color filter layer 6 are not properly aligned, or the product would otherwise have an unacceptable low quality, a failure signal Err is provided.
The apparatus comprises a fourth unit 150 for removing the color filter layer 6 from the display layer 4 upon activation of the failure signal Err.
The fourth unit 150 comprises a first and a second roll 152, 154 having a perforated outer surface. In the absence of the failure signal Err the first and the second roll 152, 154 guide the laminated product 7 towards further guidance means, here indicated by a guidance roll 160.
In the case the failure signal Err is activated, a vacuum pump 151 is switched on that evacuates the interior of the first and a second roll 152, 154. The pressure difference between the environment and the surface of the rolls causes the display layer 4 and the color filter layer 6 to be torn apart. The display layer 4 is carried away by the first roll 152 and the color filter layer 6 is carried away by the second roll 154. After a sufficient part of the display layer 4 and the color filter layer 6 are separated from each other, these parts may be separated from their respective remainders by, for example, cutting (e.g. by laser cutting). After separation, the pressure inside the rolls 154, 156 may be restored so that the disconnected parts 4a, 6a drop onto respective transport facilities 156 and 158, as indicated by dotted lines.
The apparatus of
The semi-finished product having the color filter layer 6 removably attached to the display layer 4 is then transported by transport facility 177 to test facility 124.
Test facility 124 verifies whether the semi-finished product complies with predetermined test requirements, e.g., whether the color filter layer 6 is properly aligned with the display layer, and/or whether the color filter layer is complete, i.e., whether no color filter elements are missing. In the test facility it may also be verified whether the product is free from dust particles encapsulated between the display layer and the color filter layer. This corresponds to step S6 of the method. The test facility 124 generates a signal Err having a value dependent on the outcome of the test generates a test signal Err. The tested semi-finished product is transported by transport facility 178 to a distribution unit 145. If the test signal Err indicates that the semi-finished product does not comply with the requirements the distribution facility transports the semi-finished product by transport facility 179 to the fourth unit 150 for removing the color filter layer 6 from the display layer 4. The fourth unit 150 comprises a facility that removes the intermediate substrate carrying the color filter from the display layer. Therewith the color filter layer 6 is released from the display layer 4. This corresponds to step S8 of the method. Then the display layer 4 from which the color filter layer 6 is removed is then further transported by transport facility 181 for further handling as a monochrome or a black and white display unit, corresponding to step S9. For example it may be packaged by a packaging unit 155. It is alternatively possible that the display layer 4 of which the color filter layer 6 was released is fed back to the second unit 120 by a transport facility 182 to attempt to apply a new color filter layer. In case the test signal Err indicates that the semi-finished product complies with the requirements the distribution facility 145 passes the semi-finished product to the transport facility 180 for further handling as a color display unit. The semi-finished product may for example be transported to a package unit 160. Transport and further handling correspond to step S7 of the method described with reference to
For obtaining a high accuracy of alignment, e.g. more than 10 μm between the display layer and the color filter layer, the method described with reference to
In the claims the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single component or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.
Number | Date | Country | Kind |
---|---|---|---|
NL 2005498 | Oct 2010 | NL | national |