FIELD OF THE INVENTION

The present invention generally relates to liquid crystal display modifications, and to size reduction of commercial off-the-shelf liquid crystal displays in particular.

BACKGROUND OF THE INVENTION

Many types of contemporary electronic screens are based on liquid crystal display (LCD) technology, particularly flat panel displays, ranging from televisions and computer monitors, to mobile phones and digital cameras, to billboard signs and aircraft cockpit displays. An LCD operates by blocking light from a backlight or reflector, using the properties of liquid crystals to selectively switch the display elements, or "pixels", on or off. Some older LCD models may be based on a passive- matrix addressing scheme, in which each pixel must maintain its state until refreshed without being actively driven by circuitry. In an active-matrix LCD, each pixel is connected to electronic components which actively maintains its electrical state while other pixels are being addressed. A common form of active-matrix LCD is a thin-film-transistor (TFT) LCD, which uses a grid of capacitors acting as pixels, each connected to a respective switching transistor which prevents the charge applied to a given pixel from being drained between refresh cycles, providing a sharper image.

Companies and organizations generally purchase LCDs in the form of commercial off-the-shelf (COTS) products, which are manufactured and available for sale in predefined standard sizes. However, many applications require the display to be a different size than what is available in COTS products. While it is possible to purchase a custom-made display with the desired size properties, this approach is significantly more expensive than simply modifying an existing ready-made LCD, and also necessitates a lengthy waiting period for its preparation.

Existing techniques for resizing an already manufactured LCD can be found in, for example: U.S. Patent No. 6,204,906 to Tannas, Jr., entitled: “Methods of customizing the physical size and shape of commercial off-the-shelf (COTS) electronic displays”; U.S. Patent No. 7,002,660 to Watson, entitled:“Liquid crystal displays”; U.S. Patent No. 8,068,206 to Tannas, Jr., entitled: “Customized electronic displays and methods of customizing the physical size and/or shape thereof”; and U.S. Patent No. 8,235,761 to Tannas, Jr., entitled:“Apparatus and methods for resizing electronic displays”. The existing techniques generally involve scribing the glass at the desired dimensions for resizing, breaking the glass roughly at the scribe line, and then removing the excess segment. A manual instrument, such as a roller, is applied to the glass plates during and/or after the cutting stage in order to force out air from between the plates. This resizing process, also referred to as "scribe and break", is susceptible to inaccuracies and may cause damage to the display. For example, the use of rollers tends to be ineffective in preventing inflowing air from penetrating in between the LCD plates, resulting in the formation of internal air pockets as well as the escape of liquid crystals, which serves to significantly diminish the quality and the reliability of the eventual product. In addition, the breaking or cutting of the plates tends to be faulty and imprecise, and there are difficulties in subsequently ensuring a uniform sealing. Thus, an LCD subject to the scribe and break process is unreliable and is likely to malfunction under real-world operating conditions, making it particularly unsuitable for demanding applications such as industrial machines, avionics displays, military displays, and the like.

U.S. Patent Application No. 2003/0184706 to Watson, entitled:

“Improvements in or relating to liquid crystal displays”, is directed to methods for forming a custom made LCD by removing an excess region from a pre-manufactured LCD. An LCD driver card is cut along a selected cutting line, and the ribbon connectors (TABs) which electrically connect the driver cards are disconnected from the conductive layer. A narrow strip is optionally removed from each polarizing substrates between the lines to expose their associated glass plates. A groove is cut into the exposed surface of each of the glass plates, and each plate is fractured along the length of the groove to detach the excess region from the operative region. The cut edges of the glass plates are then sealed by applying a bead of ultraviolet curing adhesive. The glass plates may be cut using a laser, or by freezing the liquid crystal between the glass plates and machining through the glass plates.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there is thus provided a method for resizing a liquid crystal display. The display includes: display plates, consisting of a front plate and a back plate; electrical circuits for operating the display; a perimeter seal securing the front plate and the back plate, and an image-generating medium in between the display plates and within the borders of the perimeter seal. The method includes the procedures of situating the display in a vacuum chamber and applying vacuum conditions within the vacuum chamber, and decreasing the temperature of the display to below a freezing temperature of the image-generating medium. The method further includes the procedures of forming a groove in the front plate and the back plate along selected groove dimensions, the groove extending through one of the display plates and terminating within the other of the display plates, and applying an adhesive into the formed groove. The method further includes the procedures of increasing the temperature of the display to above a liquidation temperature of the adhesive, and increasing the pressure of the vacuum chamber to at least atmospheric pressure. The method further includes the procedures of polymerizing the adhesive to form a seal between the display plates, and severing the display plates along selected severing dimensions. The method may further include the procedure of applying surface activation to the formed groove before applying the adhesive. The surface activation may include a low-pressure plasma, an atmospheric plasma, an inert gas plasma, and/or an oxygen-enriched plasma. The severing dimensions may be at an external edge side of the groove dimensions. The adhesive may be a UV-curing adhesive. The pressure of the vacuum chamber may be increased by nitrogen compression.

In accordance with another aspect of the present invention, there is thus provided an additional method for resizing a liquid crystal display. The display includes: display plates, consisting of a front plate and a back plate; electrical circuits for operating the display; a perimeter seal securing the front plate and the back plate, and an image-generating medium in between the display plates and within the borders of the perimeter seal. The method includes the procedure of forming a first groove in one of the display plates, and forming a second groove in the other of the display plates, along respective groove dimensions. The method further includes the procedures of applying a compressive force against the display plates, at the intended remaining sections thereof, to prevent air from penetrating between the display plates and to prevent seepage of the image-generating medium from between the display plates, and severing the display plates along the respective groove dimensions, forming an exposed inner surface at an edge of at least one of the display plates. The method further includes the procedures of applying an adhesive at the exposed surface, reducing the compressive force, allowing the adhesive to permeate into the area between the display plates, and polymerizing the adhesive to form a seal between the display plates. The first groove may be parallel to and offset from the second groove. The display may include a polarizer on at least one of the display plates, and the method may further include the procedure of removing at least a portion of the polarizer before the severing. The method may further include the procedure of wiping off liquid crystal residue and cleaning the exposed surface with a solvent before applying the adhesive. The method may further include the procedure of applying surface activation to the exposed surface before applying the adhesive. The surface activation may include a low-pressure plasma, an atmospheric plasma, an inert gas plasma, and/or an oxygen-enriched plasma. The adhesive may be a UV-curing adhesive. One of the display plates may include active electronic components, and the other one of display plates may not include active electronic components, and the display may be severed such that the display plate with the active electronic components extends beyond the display plate without the active electronic components after the severing. The display plate with the active electronic components may be a thin-film-transistor (TFT) substrate, and the display plate without the active electronic components may be a color-filter (CF) substrate. The application of a compressive force may include applying differential pressure such that greater pressure is applied at the edges of the respective display plates relative to the middle sections. ln accordance with a further aspect of the present invention, there is thus provided a resized a liquid crystal display which includes: resized display plates, consisting of a front plate and a back plate; electrical circuits for operating the display; a perimeter seal securing the front plate and the back plate; and an image-generating medium in between the display plates and within the borders of the perimeter seal. The resized display having undergone a resizing method in which the display is situated in a vacuum chamber and vacuum conditions are applied within the vacuum chamber, following which the temperature of the display is decreased to below a freezing temperature of the image-generating medium, following which a groove is formed in the front plate and the back plate along selected groove dimensions, the groove extending through one of the display plates and terminating within the other of the display plates, following which an adhesive is applied into the formed groove, following which the temperature of the display is increased to above a liquidation temperature of the adhesive, following which the pressure of the vacuum chamber is increased to at least atmospheric pressure, following which the adhesive is polymerized to form a seal between the display plates, following which the display plates are severed along selected severing dimensions. A surface activation may be applied to the formed groove before application of the adhesive. The severing dimensions may be at an external edge side of the groove dimensions. The adhesive may be a UV-curing adhesive. ln accordance with yet another aspect of the present invention, there is thus provided a resized a liquid crystal display which includes: resized display plates, consisting of a front plate and a back plate; electrical circuits for operating the display; a perimeter seal securing the front plate and the back plate, and an image-generating medium in between the display plates and within the borders of the perimeter seal. The resized display having undergone a resizing method in which a first groove is formed in one of the display plates, and a second groove is formed in the other of the display plates, along respective groove dimensions, following which a compressive force is applied against the display plates, at the intended remaining sections thereof, to prevent air from penetrating between the display plates and to prevent seepage of the image-generating medium from between the display plates, and the display plates are severed along the respective groove dimensions, forming an exposed inner surface at an edge of at least one of the display plates, following which an adhesive is applied at the exposed surface, following which the compressive force is released at least partially, allowing the adhesive to permeate into the area between the display plates, following which the adhesive is polymerized to form a seal between the display plates The first groove may be parallel to and offset from the second groove. At least a portion of a polarizer may be removed from at least one of the display plates before the severing. Liquid crystal residue may be wiped off and the exposed surface cleaned with a solvent before applying the adhesive. A surface activation may be applied to the exposed surface before application of the adhesive. The adhesive may be a UV-curing adhesive.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

Figure 1 is a block diagram of a method for resizing a liquid crystal display (LCD), operative in accordance with an embodiment of the present invention;

Figure 2A is a cross-sectional side view illustration of an LCD undergoing the groove formation procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention;

Figure 2B is a cross-sectional side view illustration of an LCD undergoing the application of adhesive procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention;

Figure 2C is a cross-sectional side view illustration of an LCD undergoing the cutting procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention;

Figure 3 is a block diagram of an alternate method for resizing a liquid crystal display, operative in accordance with another embodiment of the present invention;

Figure 4A is a cross-sectional side view illustration of an LCD undergoing the formation of offsetting grooves procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention; Figure 4B is a cross-sectional side view illustration of an LCD undergoing the polarizer removal procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention;

Figure 4C is a cross-sectional side view illustration of an LCD undergoing the application of external pressure and cutting procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention;

Figure 4D is a cross-sectional side view illustration of an LCD undergoing the application of adhesive procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention;

Figure 4E is a cross-sectional side view illustration of an LCD undergoing the release of applied pressure allowing the embedding of the adhesive procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention;

Figure 5A is a perspective view illustration of an in-plane switching (IPS) LCD subject to the resizing method of Figure 3 and severed such that the color filter (CF) plate is shorter than the thin-film transistor (TFT) plate resulting in exposed circuitry; and

Figure 5B is a perspective view illustration of an IPS LCD subject to the resizing method of Figure 3 and severed such that the TFT plate is shorter than the CF plate so as to preclude exposed circuitry, operative in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention overcomes the disadvantages of the prior art by providing methods for resizing of a previously manufactured liquid crystal display (LCD) accurately and meticulously and in a manner that avoids introducing undesirable impairments, thereby maintaining high quality and high reliability of the resized display in its application.

Reference is now made to Figures 1 , 2A, 2B and 2C. Figure 1 is a block diagram of a method for resizing a liquid crystal display, operative in accordance with an embodiment of the present invention. Figure 2A is a cross-sectional side view illustration of an LCD undergoing the groove formation procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention. Figure 2B is a cross-sectional side view illustration of an LCD undergoing the application of adhesive procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention. Figure 2C is a cross-sectional side view illustration of an LCD undergoing the cutting procedure in the method of Figure 1 , operative in accordance with an embodiment of the present invention. An exemplary LCD to be resized, generally referenced 140 (Figure 2A), includes a front plate 141 and a back plate 142, each of which is typically composed of transparent glass. Plates 141 , 142 are aligned in parallel with liquid crystal (LC) layer 145 (embodying an image-generating medium) disposed in between and are secured together with a perimeter seal. Thin conductive layers on the inner surface of at least one of plates 141 , 142 activates the light modulation properties of the liquid crystals at selected pixels of the display, by generating electric fields in selected portions causing the selective rotation of liquid crystals to block (or allow) light transmission in corresponding portions of the display. Polarizing films 143, 144 are respectively disposed on the outer surfaces of respective glass plates 141 , 142. Additional image enhancement films or filters may also be disposed on the surface of plates 141 , 142. External components of display 140, such as circuitry, may be removed prior to the resizing process (and thus not shown).

In procedure 122, the display is situated in a vacuum chamber and vacuum conditions are applied within the vacuum chamber. Referring to Figure 2A, display 140 is inserted into a vacuum chamber, referenced 150. The air is evacuated from within vacuum chamber 150 to apply a low-pressure environment inside chamber 150.

In procedure 123, the temperature of the display is decreased to below a freezing temperature of the image-generating medium of the display. Referring to Figure 2A, the temperature within vacuum chamber 150 is lowered to a temperature at least below the freezing point of the LC layer 145 of display 140, such as for example a temperature of approximately -20°C to -45°C. The temperature may be lowered, for example, by means of a cooling stage (not shown) located underneath the display 140. In procedure 125, a groove is formed in the front plate and back plate of the display along selected groove dimensions, the groove extending through one of the plates and terminating within the other of the plates. Referring to Figure 2A, a groove, referenced 146, is formed along an axis "y" orthogonal to the planar surface of plates 141 , 142 at a cross- section "go" of display 140 situated proximal and adjacent to the resizing dimensions. In other words, groove 146 is formed at or near the proximal edge of the intended resized dimensions of display plates 141 , 142, such that groove 146 will be included in the remaining portion of resized display. Groove 146 is formed at a controlled depth such that it extends completely through front plate 141 and terminates within back plate 142, although the plates may alternatively be reversed, i.e., such that the groove is formed completely through back plate 142 and terminates within front plate 141. The formation of groove 146 may be implemented using a suitable precision cutting instrument or apparatus, such as a CNC glass cutting machine, or a sawing wheel.

In optional procedure 126, a surface activation is applied onto the formed groove. Referring to Figure 2A, groove 146 is treated, by applying plasma activation or other surface modification, in order to increase the chemical interaction between the subsequently applied adhesive with the surface area of groove 146, i.e., to ensure that the adhesive bonds effectively rather than slipping off. For example, the surface activation may involve the application of a low-pressure plasma or an atmospheric plasma, and/or an oxygen-enriched plasma (e.g., an argon-oxygen based plasma) or other inert gas plasma, onto the surface of groove 146. The application of surface activation may be implemented using a controllable machine or instrument that may be automated and which may facilitate the accuracy and efficiency of the process.

In procedure 127, an adhesive is applied onto the formed groove. Referring to Figure 2B, groove 146 is sealed by applying an adhesive or sealant material, referenced 147, to fill up the vacant portion. The adhesive 147 may be a low-viscosity flexible sealant adhesive, such as a UV-curing LCD adhesive/sealant which can be subsequently cured with a UV light source (during following procedure 130). Adhesive 147 is injected in liquid form into groove 146 and then freezes and hardens upon contact with the display plate since the LCD 140 is at a very low temperature and under vacuum conditions The vacuum environment eliminates the convection medium so that heat cannot be transferred, and thus significant temperature differences can exist between the substrate and the adhesive in close proximity. A local heating may be applied to the adhesive applicator mechanism (e.g., a syringe or a cannister) to ensure that adhesive 147 remains in a liquid form while flowing through groove 146, and will not freeze before filling up the entire groove volume. The application of the adhesive may be implemented using a controllable or automated machine or instrument. In procedure 128, the temperature of the display is increased to above a liquidation temperature of the adhesive. Referring to Figure 2C, the temperature of display 140 is raised to a temperature at least above the liquidation point of the applied adhesive 147, such as for example a temperature of approximately 15°C to 25°C (e.g., "room temperature"). This enables the adhesive 147 to flow and enhances its adhesion to the display plates 141 , 142. The display temperature may be raised, for example, by increasing the temperature of a cooling stage (not shown) located underneath the display 140.

In procedure 129, the pressure of the vacuum chamber is increased to at least atmospheric pressure. Referring to Figure 2C, the pressure level within vacuum chamber 150 is raised to a pressure level at or above atmospheric pressure (1 atm), which serves to push the applied adhesive 147 into groove 146 thus improving its adhesion (by eliminating voids). The pressure may be increased by venting (e.g., to reach 1 atm) or by compressing air or nitrogen (e.g., for above 1 atm), where nitrogen may be preferable in conjunction with certain adhesives since oxygen inhibition (which would leave the adhesive exposed surface tacky) is prevented.

In procedure 130, the adhesive is polymerized to form a seal between the plates along the groove dimensions. Referring to Figure 2C, the applied adhesive 147 undergoes polymerization causing the adhesive 147 to harden and form a firm seal along cross-section "go" of display 140. For example, a UV light source may be used to polymerize a UV-curing type adhesive. Alternatively, an auto-polymerizing adhesive may be utilized. The polymerization may be implemented using a controllable machine or instrument that may operate in an automated manner.

In procedure 131 , the front plate and back plate of the display are severed along selected severing dimensions. Referring to Figure 2C, plates 141 , 142 of display 140 are severed or cut along a severing axis, referenced "y _c — y _c ", orthogonal to the planar surface of plates 141 , 142, and adjacent to the adhesive seal 147 distally (i.e., toward the external edge side of display 140). Display plates 141 , 142 are severed completely through so as to remove an excess section thereof, defined by the section between the cutting axis "y _c — y _c " and the external display edge. The remaining section of the resized display 140' defines a reduced operative region, as compared to the initial operative region of the initial display 140. The severing may be implemented using a suitable precision cutting instrument or apparatus, such as a CNC glass cutting machine or a sawing wheel. After the plates are severed and the excess section removed, an inspection may be conducted, such as using visual, electrical and/or optical means, in order to verify the process was properly carried out and perform any necessary fine-tuning for future LCD resizing operations. The resized display may then be prepared and packaged for subsequent product shipment.

It will be appreciated that the aforementioned LCD resizing method may substantially mitigate or eliminate air from penetrating into the area between the LCD plates, as the groove formation and application of the adhesive is conducted under vacuum conditions. Furthermore, the liquid crystals (image-generating medium) are prevented from escaping from between the LCD plates, since the process takes place in low temperature conditions (below a freezing temperature of the LC) which ensures that the LC is in a solid (frozen) state and thus cannot flow out. In addition, the resizing is carried out using dedicated and highly accurate instruments, such as precision cutting tools, some of which may operate in a controllably automated manner, thereby ensuring that the resized dimensions are substantially precise, while safeguarding the display properties. As a result, the resized display can maintain high quality functioning and high reliability when operating under real-world conditions, even in the context of highly demanding display applications.

Reference is now made to Figures 3, 4A, 4B, 4C and 4D. Figure 3 is a block diagram of an alternate method for resizing a liquid crystal display, operative in accordance with another embodiment of the present invention. Figure 4A is a cross-sectional side view illustration of an LCD undergoing the formation of offsetting grooves procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention. Figure 4B is a cross-sectional side view illustration of an LCD undergoing the polarizer removal procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention. Figure 4C is a cross-sectional side view illustration of an LCD undergoing the application of external pressure and cutting procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention. Figure 4D is a cross-sectional side view illustration of an LCD undergoing the application of adhesive procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention.

Figure 4E is a cross-sectional side view illustration of an LCD undergoing the release of applied pressure allowing the embedding of the adhesive procedure in the method of Figure 3, operative in accordance with an embodiment of the present invention.

An exemplary LCD to be resized, generally referenced 170

(Figure 4A), is analogous to LCD 140 (Figure 2A). LCD 170 includes a front plate 171 and a back plate 172, each typically composed of transparent glass. Plates 171 , 172 are aligned in parallel with liquid crystals 175 disposed in between and are secured together with a UV- cured perimeter seal. Polarizing films 173, 174 are respectively disposed on the outer surfaces of respective glass plates 171 , 172.

In procedure 161 , a first groove is formed in either the front plate or the back plate of the display and a second grove is formed in the other of the front plate or the back plate of the display, along respective groove dimensions. Referring to Figure 4A, a groove, referenced 176, is formed in front plate 171 along an axis "y" orthogonal to its planar surface. Another groove, referenced 177, is formed in back plate 172 along an axis "y" orthogonal to its planar surface. According to one embodiment the first groove may be parallel to and offset from the second groove. In particular, groove 177 in back plate 172 is offset from groove 176 in front plate 171 with respect to the length (defined by an axis "x") of plates 171 , 172. For example, groove 176 is formed along cross-section "gi" of display 170 while groove 177 is formed along cross-section "Q2" of display 170. The offset amount may be equal to approximately twice the thickness of the plates, but may alternatively be larger or smaller than the plate thickness. According to another embodiment, the first groove may be aligned with the second groove, such that there is substantially no offset between the grooves. It is noted that forming the second groove at an offset to the first groove may facilitate the resizing process and may improve reliability, such as by providing a larger surface area for the adhesive application (in procedure 167). Each groove 176, 177 is formed at a controlled depth and terminates within the respective plate 171 , 172. Grooves 176, 177 may be formed using a suitable precision cutting instrument or apparatus, such as a CNC glass cutting machine or a sawing wheel.

In optional procedure 162, at least a portion of a polarizing film is removed from at least one of the display plates. Referring to Figure 4B, a portion of polarizing film 173 and/or polarizing film 174 is removed, without damaging the underlying glass surface of the respective plate 171 172. The polarizing film 173, 174 may be removed using a suitable cutting or scraping apparatus. The removal of the polarizer may facilitate the embedding of the subsequently applied adhesive, and further enable the UV radiation to reach the adhesive during the curing process (procedure 169).

In procedure 163, a compressive force is applied against the front plate and the back plate. Referring to Figure 4C, the display plates 171 , 172 are pressed against one another, such as by using a press, or other suitable instrument, to apply a compressive force onto plates 171 , 172 at the intended remaining sections thereof (i.e., at the region of the plates that will remain part of the resized display, as opposed to the excess sections that will be removed). The pressure is applied before (and while) the plates are subsequent severed (procedure 164). The compressive force may be applied in a differential manner, such that a greater force is applied at the respective edges of plates 171 , 172 relative to the non-edges or middle sections. This differential application of pressure facilitates uniform dispersal of the subsequently applied adhesive between the plates upon release of the differential compressive pressure, since the LCD is characterized by a higher compression resistance along the perimeter of the plates as compared to the central region, and therefore without a differential application of pressure there would be less submersion at the edges and the adhesive will not fully permeate there.

In procedure 164, the front plate and back plate of the display are severed along their respective groove dimensions, while the pressure is being applied, forming an exposed (formerly) inner surface at the edge of one of the plates. Referring to Figure 4C, plates 171 , 172 of display 170 are severed or cut through along their respective grooves 176, 177. In particular, front plate 171 is severed along first groove 176, such that an excess section of front plate 171 , between groove 176 and the external edge of plate 171 , is severed. Similarly, back plate 172 is severed along second groove 177, such that an excess section of back plate 172, between groove 177 and the external edge of plate 172, is severed. The severing may be implemented using a suitable precision cutting instrument or apparatus, such as a CNC glass cutting machine or a sawing wheel, or by striking the display plates with a rotating beam causing them to break (only a gentle strike is necessary since the grooves are very deep and the remaining portion is very thin). The offset between grooves 176 and 177 results in an exposed surface of one of the plates after they are both severed, at the remaining section between the severed edge of the respective plate and the severed edge of the abutting plate. For example, Figure 4C shows an exposed surface section, referenced 178, at severed back plate 172 which is slightly longer than severed front plate 171 as groove 176 in front plate was disposed slightly inward (relative to the severed side) with respect to groove 177 of back plate 172 (although the plates may alternatively be reversed such that severed front plate 171 is slightly longer than severed back plate 172 resulting in an exposed surface section of front plate 171 ). In procedure 165, liquid crystal residue is wiped off and the exposed surface is cleaned. Referring to Figure 4D, residue of LC 175 is wiped off from the edge of display plates 171 , 172 and the exposed formerly inner surface 178 is cleaned using a suitable cleaning solvent, such as Acetone. The cleaning helps ensure that the subsequently applied adhesive will adhere to the surface.

In optional procedure 166, a surface activation is applied at the exposed surface. Referring to Figure 4D, exposed surface 178 at the edge of plate 172 is treated, such as by applying plasma activation or other surface modification, in order to increase the chemical interaction between the subsequently applied adhesive with the surface area of exposed surface 178, to ensure that the adhesive bonds effectively rather than slipping off. For example, the surface activation may involve the application of a low-pressure plasma or an atmospheric plasma, and/or an oxygen-enriched plasma (e.g., an argon-oxygen based plasma) or other inert gas plasma onto the exposed surface 178. The application of surface activation may be implemented using a controllable machine or instrument that may operate in an automated manner, and which may facilitate the accuracy and efficiency of the process.

In procedure 167, an adhesive is applied onto the exposed surface. Referring to Figure 4D, an adhesive or sealant material, referenced 179, is applied on exposed surface 178 to fill up the space defined between inner surface 178 of back plate 172 and the exposed external edge of front plate 171 . The adhesive may be a low-viscosity flexible sealant adhesive, such as a UV-curing LCD adhesive which can be subsequently cured with a UV light source (during following procedure 169). The application of the adhesive may be implemented using a controllable machine or instrument that may operate in an automated manner.

In procedure 168, the applied pressure is reduced from the front plate and back plate, allowing the adhesive to permeate into an area between the plates. Referring to Figure 4E, the compressive force applied previously to display plates 171 , 172 is reduced, or correspondingly the plates 171 , 172 undergo a partial compression stress relief along the transverse axis, such as by releasing external pressure applied with a press. Both the center and the (differential pressed) edges undergo stress relief, while different compression relief levels may be applied to the center in relation to the edges. As a result, the applied adhesive 179 permeates in between display plates 171 , 172, i.e., in between the inner surfaces of plates 171 , 172 adjacent to the exposed surface 178 of plate 172 and the external edge side of plate 171. As discussed earlier, the differential compression serves to facilitate uniform dispersal of the adhesive between the plates due to the higher compression resistance present along the perimeter of the display plates as compared to the center of the plates. In procedure 169, the adhesive is polymerized to form a seal between the plates along the groove dimensions. Referring to Figure 4E, the applied adhesive 179 undergoes polymerization, causing adhesive 179 to harden and form a firm seal between display plates 171 , 172 and at the previously exposed portion between inner surface 178 of back plate 172 and the external edge of front plate 171. For example, a UV light source may be used to polymerize a UV-curing type adhesive. Alternatively, auto-polymerizing and/or moisture cured adhesives may be utilized. The polymerization may be implemented using a controllable machine or instrument that may operate in an automated manner.

The remaining section of the resized display 170' defines a reduced operative region, as compared to the initial operative region of the initial display 170. After the resizing process is completed, an inspection may be conducted, such as using visual, electrical and/or optical means, in order to verify proper implementation of the procedures and perform any necessary fine-tuning for future LCD resizing operations. The resized display may then be prepared and packaged for subsequent product shipment.

When implementing the method of Figure 3, the glass plates of the display to be resized may be aligned such that the plate which contains the electronic components are not exposed. Reference is now made to Figures 5A and 5B. Figure 5A is a perspective view illustration of an in-plane switching (IPS) LCD subject to the resizing method of Figure 3 and severed such that the color filter (CF) plate is shorter than the thin-film transistor (TFT) plate resulting in exposed circuitry. Figure 5B is a perspective view illustration of an IPS LCD subject to the resizing method of Figure 3 and severed such that the TFT plate is shorter than the CF plate so as to preclude exposed circuitry, operative in accordance with an embodiment of the present invention.

In an in-plane switching (IPS) type of LCD, the TFT plate generally contains the active electronic components operating under differential voltages, while the CF plate does not. Referring to Figure 5A, a first IPS LCD, referenced 180, is aligned such that the CF plate, referenced 184, is cut shorter than the TFT plate, referenced 182. For example, a previously formed first groove in TFT plate 182 is offset distally from a previously formed second groove in CF plate 184, such that the severed edge of TFT plate 182 when cut along the first groove, is distal from the severed edge of CF plate 184 when cut along the second groove. As a result, a section of the inner surface of TFT plate 182 is exposed (adjacent to the severed edge), along with the electronic components (referenced 186) on the TFT surface. The exposure of the electronic components 186 on TFT plate 182 is likely to cause shifting of conductive material and electrical bridging, leading to short circuiting after seepage of the liquid crystals during the severing procedure (which arises due to the mechanical operation of wiping off the liquid crystals). In contrast, if the plates are aligned in reverse (or correspondingly if the grooves are offset in reverse), then the aforementioned problem is avoided. Referring to Figure 5B, a different IPS LCD, referenced 190, is aligned such that the TFT plate, referenced 192, is cut shorter than the CF plate, referenced 194. For example, a previously formed first groove in TFT plate 192 is offset proximally from a previously formed second groove in CF plate 194, such that the severed edge of TFT plate 192 when cut along the first groove, is proximal from the severed edge of CF plate 194 when cut along the second groove. As a result, a section of the inner surface of CF plate 194 is exposed adjacent to the severed edge, rather than a surface of TFT plate 192 being exposed. Consequently, the electronic components on TFT plate 192 are not exposed, and the risk of short circuits due to electrical bridging and LC seepage is avoided. The disclosed subject matter is similarly applicable to other variants of IPS panels and/or other types of LCDs in which the active electronic components are disposed on one of the two plates, including but not limited to: Plane-to-Line Switching (PLS) panels; Advanced Hyper-Viewing Angle (AHVA) panels; Fringe Field Switching (FFS) plates; and the like.

It will be appreciated that implementing the severing of the display plates and application of adhesive while a compressive force is applied against the plates, in accordance with the aforementioned LCD resizing method, serves to substantially mitigate or eliminate the penetration of air in between the display plates, as well as preventing uncontrolled seepage of liquid crystals. In addition, the differential application of compressive force (i.e., applying greater pressure at the edges of the plates) may ensure that the adhesive is uniformly dispersed (without "pinch-points" at the corners), providing a resized LCD which is more robust and reliable and better able to withstand real-world environmental conditions. The resizing is carried out using dedicated and highly accurate instruments, such as precision cutting tools, some of which may operate in a controllable and automated manner, thereby ensuring the precision of the resized dimensions while safeguarding the display properties. As a result, the resized display can maintain high quality functioning and high reliability during its subsequent application in real-world conditions. The ability to resize an already manufactured LCD, such as a COTS LCD, reduces considerable expenses and resources that would otherwise be required in ordering a brand-new custom-manufactured display with the desired dimensions.

While certain embodiments of the disclosed subject matter have been described, so as to enable one of skill in the art to practice the present invention, the preceding description is intended to be exemplary only. It should not be used to limit the scope of the disclosed subject matter, which should be determined by reference to the following claims.