JP2007512667A - Method and system for patterning organic light emitting diode displays by printing - Google Patents

Abstract

A device having a still image that can self-light when activated, comprising pixel components of an image printed using luminescent ink on a layer of an organic light emitting diode (OLED) device, the outer shape of the pattern being defined only by the pixel , Formed without the need for preforming the layer. Pixels are printed using inkjet technology on a layer such as the PEDOT layer or cathode of the OLED, requiring only a single anode and a single cathode to operate all the pixels simultaneously, and select pixels separately There is no need to address. The color pixel is formed using light emitting inks of different colors.
[Selection] Figure 3

Description

  The present invention relates to an organic light emitting diode (OLED).

  Flat displays are now becoming a necessity. The most common in large devices are LCD panels as an alternative to computer CRTs and plasma displays as alternatives to very large television CRTs. There are also small devices that use LCD-type flat panels, such as mobile phones and PDAs.

  All of these devices are based on the same patterning principle and divide the screen into an array of pixels ("pixels") of less than 1 mm arranged along columns and rows, of which the electric power is on a column and row basis. A device that performs addressing is a “passive matrix” display. In the case of an “active matrix” display, addressing is performed individually. When addressing, special electronic equipment and software are used.

  Such address designation requires that the displayed image be changeable, that is, a moving image. In the case of an LCD, a pixelized structure is essential for display design. The same is true for plasma displays, where a plasma display consisting of a large number of cells filled with gas needs to be addressed on an individual cell basis.

  Recently developed in the field of displays are so-called organic light emitting diodes (OLEDs). OLED displays are based on organic materials that emit light when excited by an electric current. With respect to this application, it is stated that an OLED display (referred to as a PLED display) comprising an organic material composed of a conjugated polymer can be produced by discharging a solution of the polymer through a fine nozzle as utilized in an ink jet device. It is enough if you keep it.

  Attempts have been made to apply such materials to applications that use the emissivity of OLEDs to provide a static display rather than a moving image. Note that the term “still” in the present invention means that the displayed image is constant and does not change.

  European Patent No. 1351303 by Eastman Kodak Co., Ltd. published on October 8, 2003 (invention name “display of selected image using organic light-emitting display”, Patent Document 1) includes one or more of each. An organic light emitting display device that displays a selected image among a plurality of images having a desired color and a method of manufacturing the same are disclosed. The image is a still image and there is no need for an address instruction.

  An image is realized by the following method using the shape of the color created by the OLED. First, an electrode that is either an anode or a cathode is formed on a substrate. Next, a luminescent material designed to emit light of a specific color corresponding to the shape of the electrode is deposited in a region occupied by the shape of the electrode. By spatially combining micro regions of different colors, the formed electrode has a desired specific color when lit simultaneously. In such a method, shaping the electrode is the first basic requirement.

  By such means, color icon displays are created on the substrate, each icon is lit separately, and the shape of each icon is pre-formed by electrode patterning.

  U.S. Pat. No. 6,501,218 published on Dec. 31, 2002 (Dugal et al., “Outdoor electroluminescent display device”, Patent Document 2) describes an OLED display. , The anode, the cathode or both are patterned, and light is emitted only in the region of the patterned electrode.

  U.S. Pat. No. 5,902,688, published May 11, 1999 (Antoniadis et al., "Electroluminescent Display Device", Patent Document 3) includes an anode, a cathode, an insulator and an organic material. An electroluminescent display device having an electroluminescent layer is disclosed. A patterned insulating layer is inserted between the anode and the hole emitting layer or between the cathode and the electron emitting light emitting layer. Such an insulating layer is made of a photoresist epoxy material, and can be patterned by irradiating with UV light through a mask during manufacturing.

Where the UV light strikes the photoresist, the photoresist is “cured” to leave that portion, but the unexposed photoresist is washed away. As a result, the insulating layer is patterned, light emission is blocked in the patterned region, and a complementary pattern is displayed with respect to the non-insulating region.
U.S. Pat. No. 6,582,756 published on June 24, 2003 (Antoniadis et al., Entitled “Method and apparatus for producing polymer-based electroluminescent display”) describes the manufacture of an electroluminescent display. Methods, substrates used and apparatus are disclosed. The display is preferably constructed on a pre-configured substrate that includes a flexible base layer having a conductive surface on one side. The substrate comprises a plurality of wells defined by a barrier layer formed by a mask, each well having an electrode layer electrically connected to the conductive surface.

  In all of the above patent publications, a result indicating a discontinuous region in the insulating layer or a patterned electrode region is obtained. The visual impression of the person viewing the display is the same whether the patterned image is realized as “negative” in the case of insulating material or “positive” in the case of patterned electrodes.

  Creating a patterned insulating layer or patterned electrode requires the use of a mask and multi-step processing, and the need to replace the mask when different patterns are to be used in different displays. Furthermore, it may be very difficult or even impossible to use such a method if multiple colors are to be used in different areas.

  Further, in US Pat. No. 5,902,688, an expensive luminescent material needs to be coated on the entire surface even when only a part of the coating is actually used.

An OLED display panel based on a light emitting polymer has a relatively simple multilayer structure as shown in FIG.
1. Base layer 1 of transparent glass or plastic material.
2. A relatively transparent anode 2 made of indium tin oxide (ITO) deposited by sputtering on a transparent layer.
3. A hole emission layer 3 formed of an ultrathin film of a material such as PEDOT (polyethylenedioxythiophene). This layer can be created by spin coating, doctor blade coating or ejection from an inkjet device.
4). An electron emission layer 4 which is a light emitting layer made of a conjugated polymer or a phosphate conjugated polymer having a PPV or polyfluorene structure. For the sake of brevity, it will be referred to as PPV in the drawings and will hereinafter be referred to as PPV.
5). A cathode 5 made of Ca, Au or Al deposited on the layer 4 by sputtering or applied as a foil. Like layer 4, this layer need not be transparent.
6). A sealing layer (not shown) for sealing other layers from moisture and oxygen.

  The combined thickness of all the layers can be less than 1 mm, and if a plastic material is selected as the substrate, this kind of flat panel display can be made to fold or follow a curved surface.

  Most of the currently available PLED flat panel displays are configured to display moving images, have a large number of pixels that can be addressed to dynamically change the display, and display very beautiful video images Is possible.

  U.S. Pat. No. 6,565,231 published on May 20, 2003 (R.S. Cook, title of the invention “OLED organic area lighting device”, Patent Document 4) includes a substrate, an anode, a cathode and An electroluminescent display device having an organic electroluminescent layer and an encapsulating cover is disclosed. The two electrodes extend out of the device and are connected to a power source. This patent relates to a composite lighting panel with various combinations of 2D and 3D freestanding lighting. However, there is no suggestion of using more than one color in one panel or incorporating the panel in another device.

  FIG. 13 of US Pat. No. 6,565,231 shows a luminaire in which two or more light sources are arranged end to end on a common line, resulting in a decorative channel such as stained glass. Show. This is another example of using an OLED to create a still image as opposed to a moving image. Furthermore, the method taught by US Pat. No. 6,565,231 differs from the above-mentioned European Patent No. 1351303 because it does not require the use of pre-shaped electrodes in the desired display pattern. However, patterning is performed using conventional lithography techniques such as deposition through a mask, integral shadow masking, laser removal, and selective chemical vapor deposition. There is no suggestion about printing the pattern using process printing techniques. Also, there is no suggestion to achieve a stained glass appearance in a single OLED panel that requires only a single electrode pair and has a plurality of color pixels defining a still image.

  Further, the light emitting layer disclosed in US Pat. No. 6,565,231 is generally composed of a host material doped with one or more guest compounds, and light emission is mainly obtained from this dopant, and can be of any color. possible. Alternatively, it is possible to provide a color filter, density filter or color temperature conversion filter on the device to achieve different colors. However, there is no suggestion to obtain three different colors by providing three pixels corresponding to the three primary colors.

  On the other hand, information describing a multicolored OLED device in the form of an active or passive display matrix configured as pixels of an X / Y matrix, each pixel including one or more colored subpixels is patent and other technical literature. Abundantly present. However, these techniques naturally require individual addressing, and in the case of a color pixel, three address lines and three transistors are required for RGB. Such an OLED matrix device is intended to be used as a flat panel display for TV, computer, PDA and mobile phone displays, and the display is time-dependent to a level capable of displaying very clean video images. And having a plurality of addressable image components that can be dynamically changed.

  There are scenes where it is required to display a stationary, unchanging image, often with various colors. For example, some examples of conventional still images may be displayed on a display such as an advertising board or a craft in a museum. In such a case, the address lines and the circuits associated therewith are redundant, unnecessarily complicated and expensive.

  Accordingly, it is desirable to provide an OLED configured to display a fixed static pattern without the need to mold an anode or cathode, and without having to cover the entire area of the substrate with an insulating layer. It is even better if the shape and color are formed by a method similar to process printing.

It is even better if the shape and color are formed by the same method as process printing.
European Patent No. 1351303 US Pat. No. 6,501,218 US Pat. No. 5,902,688 US Pat. No. 6,565,231

  The main object of the present invention is to use an OLED to display a fixed image.

  It is another main object of the present invention to display a fixed image using a pixelated display where the pixels are not addressable.

It is yet another main object of the present invention to use an OLED to display a fixed image by printing an image directly on the substrate without the need for a mask protecting the area of the substrate .

  A further object of the present invention relates to the use of an OLED to display a fixed patterned image having one or more colors per display within a tile of the same size and shape as a ceramic tile. The rendered image preferably uses a patterned or pixelated display where the pattern or pixels are not individually addressable.

  Such tiles are strong enough to support the amount of pressure traditional tiles are designed to withstand on walls and floors and are easily incorporated into building components such as walls, floors and ceilings. In addition, it is preferably included in a structure that is paved with a conventional ceramic tile.

  According to a preferred embodiment, the functionality of an OLED comprising tiles is maintained even when embedded in water in a component sensitive structure or in a swimming pool wall or floor.

  It is a further object of the present invention to provide an OLED device that provides a visual experience of a stained glass window when lit by an excitation current.

  Another object of the present invention is to provide a support structure that can be curved as well as flat, while “self” lit greeting cards on paper using the same or similar methods as conventional printing. And using an OLED to display a fixed image so that it can be held in an upright position on a flat horizontal surface. It is preferred that the functionality of such a greeting card is enabled by operating only when receiving a command.

  For this purpose, the present invention discloses an OLED that enables display of a fixed pattern that is simple and cost effective, and a method for manufacturing the OLED. Since the manufacturing method is as simple as ink jet printing on paper, the patterning of the displayed image can be done separately for each display. According to the present invention, a patterning method is proposed which requires only two electrodes, very few, without the need for column and row addressing or individual pixel addressing.

Therefore, according to the first aspect of the present invention, a method for creating a self-lighting still image,
Printing the constituent pixels of the image on the layer of an organic light emitting diode device (OLED device) using luminescent ink;
Providing a cathode and an anode for applying a voltage to the organic light emitting diode,
In the printing step, there is provided a method characterized in that the patterning is performed such that the outer shape of the pattern is defined only by the constituent pixels without masking and pre-molding the layer.

According to a second aspect of the present invention, it has a still image that can be self-lighted when activated,
Containing the constituent pixels of the image printed using a luminescent ink on a layer of an organic light emitting diode device, the outer shape of the pattern is defined only by the pixels and formed so as not to require masking and preforming of the layer An apparatus is provided.

  Such a display device does not require a backlight that consumes the power required by a liquid crystal display (LCD), and can be battery powered, as opposed to the high power required by a plasma discharge panel. is there. Furthermore, the manufacturing method is very simple, like inkjet printing, and the printing results are very different where the printing ink is radioactive rather than reflective. By utilizing the principles proposed by the present invention, it becomes possible to control very fine details such as dot size, color density and tint density of radiation printing in a manner similar to that used in reflective ink printing, and the complexity of the electrodes. There is no need to perform patterning or insertion of a patterned insulating layer. Therefore, flexible patterning such as the display according to the present invention facilitates use for new applications, some of which will be described below.

  According to the present invention, process printing of an organic luminescent solution is provided to create a still image. In a preferred embodiment, such printing is performed by spraying a solution containing polyfluorene or PPV from a fine nozzle as in an inkjet printing apparatus. As previously mentioned, inkjet devices using OLED solutions have been used in the past, but for different purposes: red, green, blue in a regular order to create addressable pixels. A droplet was ejected. Although the present invention utilizes similar inkjet ejection technology, it is designed to create complex still images, is similar to conventional process printing, and can also be performed by an inkjet apparatus.

  2A and 2B summarize the features and outline of the differences between conventional process printing and the one proposed by the present invention, which will be outlined in more detail below.

  According to the present invention, the creation of a still image is made by direct inkjet printing of a solution of light emitting polyfluorene or PPV having one or more colors. In order to obtain a full color image, red, green and blue are almost sufficient, but additional colors may be added if it is desired to increase the color gamut.

  The US company HW Sands supplies not only red, green and blue emitters for moving picture display, but also yellow, orange and blue / green emitters. In addition, Canadian American Soybean Seesees supplies orange, yellow and purple emitters in addition to red, green and blue emitters. When such emitters are used alone or in combination and printed in the same manner as conventional process printing, any color can be obtained by ejecting the emitter's color solution through a fine nozzle as used in inkjet printing. The pattern can be printed easily.

  Generally available inkjet printers print by so-called process colors. The combination of four inks reproduces most of the visible colors. These inks are transparent and function as a filter when printed on a thin film. White light passes through the ink and is reflected by the white background to indicate the color of the ink. Such inks are called subtractive inks because they reduce a portion of the spectrum of white light. A commonly used combination in printing is cyan, magenta, yellow and black. Black ink is used to enhance dark areas.

  The principle of operation of the subtractive ink determines the preprinting process used to prepare the printed image. Conventional inkjet printing images are typically generated from RGB images from a scanner, digital camera or graphics software. Such an image consists of pixels each having a certain color value. The first step is to convert these images into a CMYK file with four digital layers, and the original image will be reproduced if printed simultaneously with CMYK ink. Nowadays, such work is completely computerized and involves complex mathematical transformations.

The CMYK data may be processed to fine tune the print quality. Various lookup tables are used to improve print quality and overcome some of the limitations of CMYK inks and specific inkjet heads. Most inkjet heads print with very small droplets, which gives a fixed color intensity on the substrate. In order to make a desired color have a different density, when the droplets constituting the color are printed at different frequencies, the number of dots per square mm can be changed to change the density. Alternatively, the droplets may be printed in small groups with different areas. The process of converting a full-color image into an image composed of dots with different frequencies and sizes is called half-toning or screening.

  A halftone file is made up of separated process colors (separations), each of which is a bitmap (black and white) image. The bitmap image is further processed to be suitable for printing using a specific inkjet head. The image may be preprocessed by screening or dithering as is done in conventional printing. In addition, the image may be adjusted using known printing techniques to correct and correct the image. Such modifications include color balance, color intensity, color linearization, overlapping and the like. Although these techniques are known per se, their application has never been proposed in the field of OLEDs.

  Printing with OLED materials as proposed in the present invention is similar but not identical.

Therefore, the difference between the present invention and process printing using conventional ink is that
1. OLED “inks” are neither transparent nor reflective and are emitters.
2. The basic color of OLED is not CMY but RGB.
3. The color tone is created by either printing the dots side by side or overlapping the dots. In any case, unlike CMYK inks, color combinations are obtained by electrical interaction along with optical principles.
4). Conventional color conversion from RGB to OLED color and color conversion related to “separation” of each OLED color are completely different from CMYK conversion.
5). Due to the nature of the OLED material, the screening process strongly affects the final color of the image. This phenomenon hardly exists in CMYK printing.
6). Due to the interaction between the printed droplets, the nozzle arrangement (nozzle-mapping) is also different from the CMYK nozzle arrangement.
7). The area that does not correspond to the pattern can be “filled” with any neutral color that serves as a background where the pattern stands out, and the completed layer can be printed easily. For example, the background region can be printed using ink formed of a material that is similar in conductivity to the color ink but has no light emission, and therefore looks black. However, any other achromatic color can be used as well. This prevents a short circuit between the PEDOT layer and the cathode of the OLED that may occur in the absence of this configuration. However, this is not necessary if the electrodes are pre-shaped to avoid background areas.

  The present invention addresses such differences by incorporating software that addresses the unique characteristics of the OLED emitters described above. The present invention proposes that once the software for a specific still image obtained from an RGB scan of the image design is prepared, the image can be easily created by discharging the solution of the color OLED emitter under software control. The printing process is simpler than the conventional method of creating a color still image.

  As each solution is ejected from a dedicated nozzle or from a dedicated multi-nozzle device, the software will give instructions for all desired attributes regarding the process, such as droplet size and position on the PEDOT layer. This process handles all jetting mechanism operations for all color solutions of the OLED emitter, resulting in a final color OLED still image along the desired basic design.

  As described above, there is a fundamental difference between a conventional inkjet printing process using reflective colors and a printing process according to the present invention using radioactive colors. However, the present invention is not such a technical difference, but by directly printing pixels that form an image using PPV light emitting ink using process printing such as inkjet, a still image can be converted into a cathode of a PEDOT layer or an OLED. It is emphasized that this is attributed to the recognition that patterning is possible directly. Since it is a static pattern, such a method does not require activation of separate address lines and electronic components of each pixel, and does not require alignment of pixels with pre-formed electronic components. Further, according to such a method, the region of the pattern layer where the image is not formed (that is, the background corresponding to the unpatterned background) can be printed with any desired achromatic color. As a result, the entire pattern is covered with ink formed of a non-conductive material, so that there is no need to previously mold the electrode. On the other hand, when it is not such a configuration, it is necessary to prevent an empty area without a pattern from short-circuiting with an adjacent layer of the OLED.

  In order that the present invention may be understood and understood how it may be practiced, the preferred embodiments are set forth below with reference to the accompanying drawings. However, these descriptions are merely examples.

  The present invention essentially proposes the use of PLEDs for the display of fixed images that allow a very simple addressing scheme compared to conventional pixelated displays.

As a result, the following advantages are obtained by the present invention.
1. Different patterns can be created on different display elements under software control.
2. If the visible pattern does not occupy the entire display area, light emitting material can be saved in non-functional areas.
3. As long as the image is fixed, a complex image of multiple colors can be created and displayed without using a plurality of electrodes or electronic addressing elements.
The present invention utilizes inkjet technology to print a pattern of electroluminescent material (described above “Layer 4”) that is desirable to depict a sharp active light image. Only one anode and one cathode covering the entire area of the display is required. Furthermore, it is continuously coated with a hole emitting layer and can be patterned simply by selectively coating the light emitting OLED material.

  This is done by injecting a luminescent material (PPV) using an inkjet device. The PPV is dissolved in a solution having a sufficiently low viscosity so that it can be ejected by an ink jet apparatus. Suitable solvents are, for example, anisole and benzene solvents. However, most ink jet devices are not suitable for this application because they dissolve in aggressive solvents. The inventors have found that it is appropriate to employ an ink jet device made only of glass and silicon, in which components are joined electronically instead of an adhesive. Ink jet devices employed to practice the present invention should not be damaged or contaminated by the PPV solution. Such requirements are met by an inkjet device, such as PL-128, Israeli Industrial Inkjet Technology, made of electronically bonded silicon and glass.

  With a suitable inkjet device, a pattern composed of an electroluminescent layer can be obtained quickly. As each single display is printed, the patterns on the different displays may be the same or different, which is achieved by controlling the printing with software. The display is electrically activated by passing current between the continuous cathode and the continuous anode of the display.

  FIG. 3 is a diagram showing a pattern of the shape of the letter “A” obtained by printing the luminescent material.

  A microjet apparatus using a liquid droplet of several tens or a few picoliters with a resolution of 300 or 600 dpi can not only eject a PPV solution but also form a uniform PPV layer. If necessary, uniform color and brightness can be obtained. This is achieved by controlling the number and size of the droplets at each point.

  Printing the PPV material in a pattern that does not occupy the entire area of the display provides an area where the PEDOT layer is in direct contact with the cathode. Thus, in such a region, the cathode and anode are separated only by a thin, partially conductive PEDOT layer. As mentioned earlier, the present invention avoids the “shorts” that result from printing such areas that are not covered with a luminescent ink that includes a non-conjugated polymer that functions as an insulator.

  As shown in FIG. 4, if the thickness of the PPV light emitting layer can be accurately controlled, it is possible to create a lighting sub-pattern within the fixed print pattern. Where the layer is thin, the lighting is weaker (ie, the color is lighter) than where the layer is thick. Such sub-patterning is done by increasing rather than reducing the luminance as described in GB 2,384,115. According to British Patent No. 2,384,115, the brightness of a part of the display is lowered using patterned UV light irradiated through a mask. The opposite is happening in the present invention, where brightness is increased by creating a pattern containing more of the light emitting PPV material using inkjet patterning.

  As another method for enabling stepwise lighting, screening and dithering similar to those used in conventional printing can be used. If the material is ejected into discrete dot shapes and the dot density increases, the level of lighting increases. Therefore, as shown in FIG. 5, the closer the dots are (close screen), the higher the illuminance.

<New embodiment made possible by the present invention>
In accordance with the present invention, it is only necessary to create certain colored lighting symbols and markers as suggested by the aforementioned US Pat. No. 5,902,688 and US Pat. No. 6,501,218. It is possible to create symbols and markers made of one or more colors. Thereby, since various colors of PPV are commercially available, it is possible to create a desired pattern using different colors from different nozzles. An ink jet apparatus is composed of several ink jet heads, each discharging a PPV solution of a different color.

  Basically obtained by C, M, Y and K ink jet printing on paper as was done conventionally, using three separate ink jet heads, each with R, B and G colors. It is also possible to print the pattern in the form of a color image having the same resolution and details as those presented. The difference is that the printed image of the OLED emits light whenever the printed dots do not reflect the color back light and current is flowing between the common cathode and the common anode in the display. .

  Such an image is a “fixed” image and is not dynamically changeable like a matrix display. This difference is due to the fact that the present invention requires only two electrodes that are not addressable, as opposed to the multiple column and row electrodes required for active matrix displays. Further, there is no need for each transistor for each pixel as in the active matrix. Furthermore, in contrast to the complex software and drivers required for matrix type OLED displays, no software or drivers are required to operate the display of the present invention.

  Thus, if the image depicted on the display is originally a static and fixed image, the device of the present invention is preferred over the conventional matrix driven OLED display due to its simplicity and low cost.

  Such aspects of the invention can be used in new products such as self-lighting still images and self-lighting greeting cards that are manufactured individually or in large quantities and are framed or unframed. All of this is possible with the digitally controlled emission “ink” printing method without the need to selectively address the pixels. Examples of such applications are described below with particular reference to FIGS.

  Although the invention has been described with particular reference to producing fixed images on OLED displays using inkjet technology, each pixel emits light of the desired color when a voltage is applied between the composite anode and cathode. It is understood that other printing techniques may be used provided that each pixel of the resulting image is accurately color-synthesized, i.e. can be controlled so that the balance of R, G, B is accurate. I want. Accordingly, suitable printing techniques include color offset printing and the like.

  Also, the present invention has been described with particular reference to printing patterns on the PEDOT layer or on the cathode of the OLED, which indicates that it is particularly effective to print patterns on these layers. This is because they found it. However, the present invention also encompasses OLED devices where the pattern is printed on other layers of the OLED.

  Having described the principle of constructing an OLED device using inkjet printing of color pixels, it displays a fixed static pattern using luminescent ink that forms a patterned insulating PPV layer of an OLED with only two electrodes Several commercial applications of such technology for forming products are described below. The commercial value of the application described below is that it uses light-transmitting ink, uses pixels that operate with a single cathode and anode and do not require individual addressing, This eliminates the need for separate transistors necessary for conventional OLEDs that perform dynamic display. Furthermore, even if the pattern includes colors formed by R, G, and B color pixels that are the three primary colors, only two electrodes are required. In other words, it is a great saving in complexity and cost compared to the prior art where all three pixels of each of the three primary colors require unique transistors and address lines.

  It should be noted that in the applications described below, it is also possible to implement the pattern using other techniques, and therefore the structure will be described in connection with the use of inkjet printing, but the pattern may be formed using conventional techniques. It should be understood that configuration is possible.

  A fixed image of an OLED display prepared according to the invention described above with reference to FIGS. 2A-5 was realized on a glass plate A having a sufficient thickness to withstand the pressure applied to the tile, as shown in FIGS. This is mainly related to the position of the tile, i.e. whether the tile is attached to the wall or to the floor. Once the OLED display is sealed, the glass plate A is made into another plate B made of glass, cement, concrete, metal, or plastic such as ABS or polycarbonate, with a sufficient thickness according to the allowable external pressure of the tile. Adhere or join with frit. Since the standard thickness of ceramic tiles is 9 mm, those skilled in the art can understand that it is possible to create tiles of sufficient strength that can be installed not only on the walls covered by the tiles but also on the floor. Will be understood.

  The present invention is not limited to improved tiles or similar thicknesses as an alternative to regular earthenware tiles, but is also applicable to self-supporting devices with thicknesses less than or greater than 9 mm.

  FIG. 6 is a cross-sectional view of a tile device in a basic embodiment, showing glass plates A and B and an OLED sandwiched therebetween. Two wires connected respectively to the anode and cathode of the OLED are not shown.

  The glass plate A is assembled with the back plate B so that the OLED printing surface of the glass plate A is positioned opposite one of the surfaces of the back plate B. Thus, the OLED that forms the image is sandwiched between the two plates and can be viewed through the transparent glass plate A.

  When an adhesive is used, it can be applied on the outer insulating layer of the OLED on the glass plate A having compatibility with an adhesive such as an acrylic adhesive. Next, the 2nd board B is joined with an adhesive agent. In this way, the two plates are configured to sandwich the OLED therebetween. The cathode and anode of the OLED are each connected to the wiring, and a part of the wiring is left outside the device before bonding for connection to the power source.

  FIG. 7 is a cross-sectional view of the second embodiment, with the narrow end portion rising along the periphery of the plate B. FIG. The OLED is not assembled on the entire surface of the glass plate A, leaving a blank area on the edge of the glass plate A along the periphery. The two plates are joined together with an adhesive, or the glass frit is melted and joined together. In this embodiment, a space is formed between the two plates. This empty space is used to house a flat thin battery type OLED power supply in the tile. In such a case, the wiring soldered to the anode and cathode is kept inside the apparatus.

  FIG. 8 is a cross-sectional view of the third embodiment and is similar to the second embodiment. The glass plate B incorporates one or more indentations, which are indentations for storing batteries.

  As shown in FIG. 9, the lighting tiles described and illustrated in FIGS. 6-8 can be neatly embedded in existing pavement parts. For example, it may further comprise means allowing insertion into a floor, wall or ceiling covered with conventional tiles or other tiles according to the invention. To this end, according to one embodiment, the tiles comprising the OLEDs are provided with a flat thin film of elastic material such as RTV on the back as well as on the sides, the size of the device being ceramic, marble, glass or mosaic or any Made of other kinds of decorative tiles, very close to the size of the surrounding tiles. When manufactured in this manner, the tile of the present invention can be inserted into the assigned place with an appropriate force and can be held without using cement.

  The method of fitting the tile of the present invention into a frame surrounded by other tiles made of earthenware, stone or glass is not limited to the method using RTV. For example, other various materials such as metal and plastic may be used for insertion, and selection of the material for insertion may be determined according to engineering and architectural needs.

  Although the invention has been described above with respect to flat tiles, it is not limited to such tiles. The present invention also includes curved tiles. For example, if the glass plates A and B are manufactured as bent plates having an appropriate curvature by molding with a mold, they can be combined with an apparatus having the same geometric properties.

  The operation of the OLED device sealed in the tile of the present invention can be performed with any switching element if the device receives power from an external power source. If the OLED device and its power source, for example a battery, is sealed inside the tile, the operation of the OLED, i.e. switching on the connection to the power source, can be switched by various means such as electromagnetic or RF circuits, or light It can be performed by a sensor or a pressure sensor. The selection of the type of the switching circuit may be determined according to the specific use and accessibility of the tile.

  In use, the OLED self-illuminating tile as described above with reference to FIGS. 6-9 serves as a light source panel embedded in a surface covered with conventional tiles. It has enough strength to function even on the floor. It further comprises a dedicated sealed power supply, and thus is an improvement over previously proposed lighting panels that do not have the resilience of the tiles of the present invention or a dedicated power supply.

  More importantly, the tiles of the present invention have the advantage of the decorative features of patterned or pixelated OLEDs having only two electrodes. This makes the tiles of the present invention more suitable for tile-covered surfaces, most of which have a decorative function.

  OLED devices sealed and patterned in this type of tile are very useful in the creation of emergency or warning lights. This is because such signs are well protected, have a dedicated embedded power source, and look good even in daylight and dark conditions.

  Next, with reference to FIGS. 10-12, the 2nd use of the stationary color pattern applicable to OLED is demonstrated. This uses process printing such as inkjet technology and resembles the visual effect of a conventional stained glass window, for example. When a sufficient amount of sunlight is available, no current is passed through the device, in which case, according to one embodiment, a luminescent layer colored so that the device is substantially transparent. Using such an embodiment, the OLED pattern resembles the visual effect of a conventional stained glass window, and the OLED pattern corresponds exactly with respect to contour and color. This device is placed in front of a conventional stained glass window so that the two patterns are in the correct positional relationship.

  When no voltage is applied to the OLED device, it remains substantially transparent, so a conventional stained glass window is visible through the OLED device. When a voltage is applied to the OLED device, light appears from a pattern resembling a stained glass window. If this operation is performed at night or when the surrounding sunlight conditions are bad, the conventional stained glass window will be dark, but the OLED device is placed on either side of the conventional stained glass window, the pattern lights up, The effect of backlighting through the stained glass is brought about. In order to make the daytime and nighttime appearances as similar as possible, the voltage applied to the device may be controlled.

  According to another embodiment, the OLED device is not transparent. In this case, the OLED pattern can only be seen when a voltage is applied to the OLED device. When no voltage is applied, the pattern of the conventional stained glass window is not visible even if it is opaque and mounted in alignment with the conventional stained glass window. Thus, such an embodiment can be used as a substitute for a conventional stained glass window, in which case there is no need for precise pattern alignment between the conventional stained glass window and the OLED device.

  FIG. 10 schematically shows a multilayer structure of the transparent stained glass OLED panel described in the first embodiment. The OLED is constructed as described above with reference to FIG. 1 and comprises a base layer 11 of transparent glass or plastic material and indium tin oxide (ITO) deposited on the transparent layer 11 by sputtering. And a relatively transparent anode 12 made of The hole emitting layer 13 is formed by spin coating, doctor blade coating or ejection from an inkjet device using an ultra thin film of “PEDOT” (polyethylenedioxythiophene) or similar material. The electron emission layer 14 is a light emitting layer and is made of PPV. The cathode 15 made of Ca, Au or Al is deposited on the PPV layer 14 by sputtering or applied as a foil. Like the PPV layer 14, this layer need not be transparent. Finally, a transparent sealing layer 16 such as glass is provided to seal other layers from moisture and oxygen.

  FIG. 11 is a diagram showing a continuous color area printed using a luminescent ink on the PPV layer 14 using an inkjet technique or the like. When a voltage is applied between the anode 11 and the cathode 15, the color area is shown. Emits light corresponding to the color of the lit pixel. The luminance level has a non-linear relationship with the voltage applied between the anode and the cathode. The brightness may be controlled manually or by a programmable servo mechanism by connecting the two electrodes to a power source via a voltage level controller (not shown). The controller receives an input from an optical sensor that measures the level of ambient light, and uses this input to raise or lower the voltage to a desired level by firmware included in the controller.

  FIG. 12 shows another embodiment. This is an imitation of the old stained glass design in which colored glass pieces are held together with copper strips. In the present invention, the copper joint is formed in a pseudo manner with a thick black line printed with black resin using an ink jet or lithography process so as to overlap each common boundary between successive color regions.

  Thus, according to the present invention, an OLED device that provides a visual experience like a stained glass window when lit by an excitation current is provided. The color pattern can be realized using an inkjet printing technique as described above with reference to FIGS. However, it is possible to deposit the color region using other techniques. The stained glass OLED device and pattern according to the present invention as shown in FIGS. 10 to 12 is compared with the conventionally proposed effect as described in the above-referenced US Pat. No. 6,565,231. Thus, not only the pattern printing is simple, but also the fact that it is only necessary to deposit the color region on a single panel, so that it is not necessary to arrange a plurality of panels side by side.

  If a voltage is applied between the two electrodes 11 and 15 by creating an OLED patterned on the glass substrate that fits into the window frame in this way, visual recognition of the stained glass window can be obtained.

  A further application of the OLED device according to the present invention relates to a greeting card with decoration by light emission. Many decorated greeting cards are now printed on thick paper that is raised in attractive and eye-catching glossy foils and bright colors. Some companies, such as the Dutch company Lumax, print greeting cards on translucent paper and supply them with tealight candles and bulb lamp holders. Place the card on the holder and illuminate it from the back. These cards are manufactured using conventional printing techniques.

  FIG. 13 schematically shows an open greeting card according to the present invention. The decorative pattern formed by printing on the PPV layer of the OLED as described above is attached to one side of the card and connected to a flat battery mounted on the other side. One wire is connected from the anode of the OLED to the positive terminal of the battery, and the cathode of the OLED is connected to the negative terminal of the battery via a switch formed in a T-shaped piece or the like. When this T-shaped piece is stretched and pressed against a looped wire connected to the battery, an electrical contact is formed.

  FIG. 14 shows the closed state of the card. Since the T-shaped piece is retracted, the battery circuit is incomplete and the OLED is not operating. When the card is opened, the T-shaped piece extends and contacts the loop, the circuit is completed and the OLED is lit. A switch is effectively connected between the anode of the OLED and the positive terminal of the battery.

  A fixed image is displayed on a transparent thin film acting as a substrate. The thickness of such a substrate may be the same as the thickness of the paper. However, it is desirable to use a sheet having a thickness of 200 gm or more for practical use and appearance. The thickness of all other layers of the OLED is less than 1 mm. Alternatively, the OLED may be printed on a thinner substrate and placed on a thick paper.

  As a result, the OLED image pattern is mounted on the “card” and can be mailed in an envelope. As long as no power is supplied to the OLED, only a monotonous, non-bright, unclear color image can be seen. When power is supplied, an image clearly appears as a lighting pattern having brightness close to that of a CRT or LCD screen having a clear color and high contrast. This OLED device is designed so that power is automatically supplied when the recipient removes it from the envelope. This can be done using an activation circuit or the like that senses light, and such techniques are well known in the art.

  The applications described above with reference to FIGS. 6-14 are exemplary and are abundant products having still images formed using OLEDs that are commercialized according to the principles of the present invention and constructed in accordance with the present invention. This is merely to show that it is easy to manufacture. Other applications will be helpful to those skilled in the relevant fields.

FIG. 1 schematically shows a conventional OLED display panel based on a light-emitting polymer having a relatively simple multilayer structure. FIG. 2A is a flowchart showing main processes necessary for inkjet printing using a light reflecting ink of a conventional example. FIG. 2B is a flowchart showing main processes necessary for ink jet printing using the luminescent ink of the present invention. FIG. 3 shows a pattern of letter “A” shape obtained by printing a luminescent material. FIG. 4 schematically shows how a sub-lighting pattern is created in the fixed print pattern by controlling the thickness of the PPV layer at an arbitrary point. FIG. 5 illustrates the state of stepwise lighting using screening. FIG. 6 is a cross-sectional view of a tile having a pattern formed by inkjet printing using OLED technology, according to an embodiment. FIG. 7 is a cross-sectional view of a tile having a pattern formed by inkjet printing using OLED technology according to another embodiment. FIG. 8 is a cross-sectional view of a tile having a pattern formed by inkjet printing using OLED technology according to another embodiment. FIG. 9 is a cross-sectional view of a tile having a pattern formed by inkjet printing using OLED technology according to another embodiment. FIG. 10 schematically shows an enlarged structure of a translucent OLED device according to the present invention. FIG. 11 schematically illustrates the patterning of the OLED device shown in FIG. 10 that provides the stained glass effect. FIG. 12 schematically illustrates the patterning of the OLED device shown in FIG. 11 where the boundaries of different color regions are indicated by thick black lines. FIG. 13 schematically shows a greeting card having a lighting pattern formed by inkjet printing using the OLED technology according to the present invention. FIG. 14 shows the card shown in FIG. 13 in detail in a closed state.

Claims (26)

A method of creating a self-lighting still image,
Printing the constituent pixels of the image using a luminescent ink on a layer of an organic light emitting diode device; and
Providing a cathode and an anode for applying a voltage to the organic light emitting diode,
In the printing step, the pattern is formed such that the outer shape of the pattern is determined only by the constituent pixels without pre-forming the layer. The method of claim 1, comprising:
Generating halftone color separation masks corresponding to each color component of the pixel and an achromatic background color, respectively;
Printing the pixels corresponding to the color components using each luminescent ink;
Printing the pixels corresponding to the achromatic background color using non-luminescent and non-conductive inks.   3. A method according to claim 1 or 2, further comprising operating a process printing press to print the color components separately.   4. A method according to any one of the preceding claims, wherein a single anode and a single cathode are provided to operate all of the pixels simultaneously, and the selected pixels need not be addressed separately.   The method according to claim 1, wherein the pixel is printed on a PEDOT layer or a cathode of the organic light emitting diode.   The method according to claim 1, wherein the pixels are formed using different luminescent inks.   The method according to any one of claims 1 to 6, wherein in a place where a higher color density is required, the color density of light of the selected pixel is changed by depositing a thick luminescent ink.   The method according to claim 1, wherein the pixels are printed using inkjet technology.   9. The method according to any one of claims 1 to 8, further comprising the step of processing the image as in conventional printing and correcting and / or adjusting the image.   The method according to claim 1, wherein the processing includes preprocessing of the image by screening and dithering.   The method according to claim 1, further comprising sealing the layer on which the pattern is printed in an apparatus. It has a still image that can be turned on when activated,
A device comprising the constituent pixels of the image printed on the layer of an organic light emitting diode device using luminescent ink, the outer shape of the pattern being defined only by the pixels and not requiring the pre-formation of the layer.   13. The apparatus of claim 12, wherein the pixels corresponding to the achromatic background color are formed of ink that neither emits light nor is conductive.   14. A device according to claim 12 or 13, comprising a single anode and a single cathode for operating all the pixels simultaneously without having to address the selected pixels separately.   14. The device according to claim 12 or 13, wherein the pixels are printed on the PEDOT layer of the organic light emitting diode or on the cathode of the organic light emitting diode.   The apparatus according to any one of claims 12 to 15, wherein the pixels include different colors of luminescent ink.   The apparatus according to any one of claims 12 to 16, wherein the thickness of a selected pixel of the pixels varies according to a color density of a predetermined light associated with the selected pixel.   18. An apparatus according to any one of claims 12 to 17, wherein the pixels are printed using inkjet technology.   The apparatus according to any one of claims 12 to 18, which is a decorative tile.   19. A device according to any one of claims 12 to 18, which is a stained glass window having a single panel with the emission color printed as a continuous area.   21. The apparatus of claim 20, further comprising black lines printed to overlap each common boundary between successive color regions.   The device according to any one of claims 12 to 18, which is a greeting card.   A decorative tile having a pattern formed on a layer of an organic light emitting diode.   A stained glass panel in which the emission color is deposited as a continuous area on a layer of organic light emitting diodes.   25. The stained glass panel of claim 24, further comprising a black line deposited to overlap each common boundary between successive color regions.   A greeting card having a pattern formed on a layer of organic light emitting diodes.

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