Patent Grant
9865184
This application claims the benefit of European Patent Convention Application No. 09012797.8, filed on Oct. 9, 2009, the substance of which is incorporated herein by reference.
The present disclosure relates to a display panel. More particularly, the present disclosure relates to an information display comprising the display panel, an appliance that comprises the information display, and a method of manufacturing a translucent carrier element of the display panel.
In electronic and electromechanical handheld appliances, which can be manually handled, light emitting elements are provided in the interior thereof, in particular in the form of LEDs, through which specific switching and operating states of the appliance are visualized to a user. These light emitting elements are typically arranged in the interior of the housing so that corresponding lighted dots can be generated that are usually associated to or with an explanatory print on the outside of the housing (for example, “Charge Status” could be printed onto the housing and the lighted dot could change between a green color and a red color).
A backlit display panel is known from DE 20 2008 008 101, which comprises a light-transparent main body, an outer light-transparent cover layer and an inner light-opaque cover layer being provided on this main body. The inner light-opaque cover layer is locally provided with a pictogram mask. With corresponding backlighting of the main body, the lighted image generated by the pictogram mask is visible through the main body and the outer cover layer.
In one embodiment, a display panel includes a translucent carrier element that has an inner side, an outer side and a display area; and at least one display element being arranged within the display area. The display element is formed by geometric structures realized as protrusions and/or depressions on both of the inner side and the outer side of the translucent carrier element. The protrusions and/or depressions are integrally formed with the translucent carrier element. Thus it is a desire to provide a display panel, an information display comprising the display panel and an appliance that comprises the information display that provide attractive display elements.
Among the advantages of various practices of the embodiments of the present disclosure are that the information display has an attractive front having a relief-like character, which is easy to clean; the display elements (pictograms) can be seen in an unlit state because of the geometric structures on the outer side of the translucent carrier element; a sharply delimited lighted area is achieved by geometric structures realized as identical and congruent depressions; the relief is lighted directly; very different visual appearances may be implemented easily by the combination of protrusions and depressions; the light intensity can be varied by differently dimensioned depressions (for example, different depths), so that lighter and darker areas or contrast intensity curves may be implemented; any arbitrary shape of the display elements can be realized; and display elements can be generated on arbitrarily shaped translucent carrier elements (flat and/or curved).
While the specification concludes with claims which particularly point out and distinctly claim the subject matter that is regarded as the invention, it is believed the various embodiments will be better understood from the following description taken in conjunction with the accompanying drawings, in which:
The display panel according to the present disclosure has a translucent carrier element, which is manufactured from an essentially translucent (plastic) material. The display panel has an inner side, an outer side, and a display area. At least one display element is arranged within the display area. The display element is formed by geometric structures that are realized as protrusions and/or depressions on both of the inner side and the outer side of the translucent carrier element, wherein the protrusions and/or depressions are integrally formed with the translucent carrier element, i.e. at least one geometric structure is formed on the outer side and at least another geometric structure is formed on the inner side that together form the display element. In an embodiment, the geometric structures formed on the inner side of the translucent carrier element are only realized as depressions. In one embodiment, the display element can be a pictogram or symbol.
In contrast to a display panel where only a light-opaque masking is applied on the inner side of a translucent carrier element and a blurry image of the masked structure would result on the outer side of the display panel, the display panel described herein having geometric structures on the outer side and the inner side of the translucent carrier element can provide display elements with, for example, a high edge sharpness and other appealing optical effects such as a halo effect.
In an embodiment, the geometric structure(s) that is (are) formed on the inner side and the geometric structure(s) that is (are) formed on the outer side of the translucent carrier element and that together form the display element have essentially identical contour and/or have essentially coinciding positions (i.e. they are congruent). As a result, the geometric structures are symmetrically formed (i.e. they are mirror images) on both sides as protrusions and/or depressions. In particular, the spatial deviation between the geometric structures formed on the inner side and the outer side, respectively, deviates by not more than about 20 micrometers (μm), and in another embodiment, by not more than 10 micrometers, where the spatial deviation is measured with respect to the normal vector of the translucent carrier element, which means that for an identical contour and position of the geometric structure realized on the inner side and the geometric structure realized on the outer side, the normal vector that contacts the contour of one of the geometric structures does so also for the contour of the other geometric structure. A high edge sharpness of the display element contours in a backlit state is achieved when both geometric structures are realized as depressions.
In another embodiment, the geometric structure formed on the inner side is realized as a depression and the geometric structure formed on the outer side is realized as a protrusion, where in particular the contour of the depression envelopes the contour of the protrusion, i.e. the protrusion may be realized within the area of the depression or in other words, the depression has larger spatial extensions than the protrusion.
In yet another embodiment, an essentially light-opaque masking is arranged on the inner side of the translucent carrier element, which light-opaque masking is not covering the geometric structure(s) formed on the inner side. The light-opaque masking may in particular be a layer of black ink, for example, applied via a printing process.
It is to be noted that the geometric structures and the various embodiments described lead to different display elements that in an active state, when the display panel is backlit by light emitting elements, have, for example, high edge sharpness when contour-identical depressions are realized on the inner side and the outer side with coinciding positions or a structure is highlighted by a surrounding diffuse bright area when a large depression is realized on the inner side and a smaller protrusion is realized on the outer side (halo effect). The effects are increased by using an essentially light-opaque masking on the inner side.
In an embodiment, the thickness of the translucent carrier element is from about 0.5 mm to about 3.5 mm and the height extension of the geometric structures in thickness direction (i.e. in the direction of the normal vector) lies in the range of from about 10% to about 50% of the thickness of the translucent carrier element. The thickness value of the translucent carrier element neglects the presence of depressions and protrusions and is measured along the surface normal.
In a further embodiment, the translucent carrier element has a curved shape, i.e. the translucent carrier element is non-planar, in particular non-planar in the display area and it is in particular having a three-dimensionally curved shape.
Multiple display areas may also be implemented on the display panel, which either have depressions on both sides or a depression on one side and a corresponding protrusion on the other side. Different characteristics of the individual display elements may be achieved by a corresponding selection.
In an even further embodiment, the display panel comprises an essentially transparent layer that covers at least a part of the outer side of the translucent carrier element. In particular, the transparent layer may be smooth on its outer side for improved handling properties as any unevenness due to depressions and/or protrusions is avoided. The essentially transparent cover may be slightly colored, e.g. to generate the effect of tinted or smoked glass. The pigments used for coloring the transparent cover essentially only absorb light but do not scatter the light so that the back-lit display elements may only loose some contrast but will not be blurred. The transparent layer can be manufactured from a plastic material. Surface effects, in particular contours may optionally be implemented on the surface of the transparent layer by gloss/matte boundaries.
According to a further aspect of the present disclosure, it is possible to provide the display panel in the area of its outer side with an imprint. For example, the outer side of the translucent carrier element can be printed or the outer side of the transparent layer can be printed. Furthermore, a laser inscription can also be implemented in the area of the display area.
An information display according to the present disclosure comprises a display panel as described and at least one light emitting element such as a LED that is arranged for illuminating the inner side of the translucent carrier element in the area of the display element such that an attractive pictogram or symbol becomes visible on the outer side of the display panel in the backlit state, where the illuminated display element can, for example, have a high edge sharpness or can be a pronounced darker symbol within a diffuse brighter area (halo effect). In an embodiment, several light emitting elements are arranged for selective illumination of several display elements such that, for example, different information can be selectively presented (for example, different operation modes of an appliance such as an electric toothbrush). In particular, the light emitting elements can be separated by light-opaque separation walls for avoiding that neighboring display elements are illuminated. An appliance according to the present disclosure comprises an information display as proposed. An appliance is in particular a hand-held electronic appliance such as a mobile phone, a laptop, a PDA, a remote control, a camera, an electronic tool (e.g. drilling machine), a toothbrush, a shaver, a kitchen device etc.
The present disclosure is also concerned with a method of manufacturing a display panel as proposed. The manufacturing method comprises the step of injecting a translucent material, in particular a plastic material having translucent properties, into an injection mold, which injection mold provides a negative image of the geometric structures such that the translucent carrier element is formed.
In an embodiment, a transparent layer is injection molded at least over a part of the translucent carrier element in a second injection molding process step. In another embodiment, an essentially light-opaque masking is applied onto the inner side of the translucent carrier element.
In the different embodiments from
In the shown embodiment, the display panel 31 is realized as a housing part of an electromechanical tooth cleaning device (electrical toothbrush 41—
The design of the display panel 31 is further visualized by cross-sectional views shown in
With respect to
In the embodiment shown in
Areas of low material thickness 15 result from the congruent depressions 5, 6 on both sides of the translucent carrier element 10, whereby a higher light output occurs in these areas. In addition, a significantly brighter light output occurs in the area of an outer edge 61 and an inner edge 65 through optical properties, whereby contours of the display elements 21-25 which appear bright are visible.
The essentially transparent layer 7 is provided on the outer side 2 of the translucent carrier element 10. This transparent layer 7 fills up the depressions 6 formed on the outer side 2 of the translucent carrier element 10 and a smooth face 7a of the transparent layer 7 can be achieved. Although it is not shown here, it is also possible to implement further display elements such as icon or image contours in the area of the outer side 2, in particular inside the depressions 6, in that bars are realized in the depressions 6, which in turn project forward out of the depressions and may also be printed by a printing method. The bars printed in this way may be dimensioned so that they are then embedded in the transparent cover layer 7 and do not protrude beyond the cover layer outer side 7a.
The display area 3 of the display panel 31 is designed in a curved shape D in this example according to
Another embodiment of a display panel 31 is shown in
As shown in
In general, differing light effects may be achieved by the concept according to the invention through a combination of geometric structures realized as depressions and protrusions that form the display elements 21-28. Through a depression 5 on the inner side 1 in combination with a masking layer 4, the lighted area of the display elements 21-28 may be intentionally defined. Via sharp edges 61 and small local depressions 62 in the protrusions filigree shapes of the display elements can be realized.
A further exemplary embodiment of a translucent carrier element 10 is shown in
A further exemplary embodiment of a translucent carrier element 10 is shown in
In a method for manufacturing a display panel, the translucent carrier element 10 having geometric structures forming the display elements 21-28 is produced in an injection-molding method by injecting a (plastic) material having translucent properties into an injection mold. Due to the precise techniques in the manufacturing of the injection mold, a high precision of the molded product can be achieved such that a relative positioning accuracy of the geometric structures on the inner side 1 and the outer side 2 of the translucent carrier element 10 of less than 20 micrometers, in particular about 10 micrometers can result. This high relative positioning precision leads in the case of congruent and identical depressions on the inner side 1 and the outer side 2 to very sharp edges of the display elements 21-28 when being illuminated. Other techniques may not achieve this high precision (for example, a relative positioning deviation of up to 200 μm could result) and a much more blurred impression of the display elements 21-28 would result.
In a further method step of the injection molding method, the essentially transparent layer 7 is injected onto the translucent carrier element 10 using a further injection mold and injecting a material having essentially transparent properties, for example, polycarbonate (PC) or polymethyl methacrylate (PMMA).
The technique according to the present disclosure is suitable for display panels 31 that are used in any type of appliance, in particular in electrical appliances which have display elements, in order to give the user feedback about the operating state or other information. The backlighting of the display area 3 is performed by active light emitting elements, in particular by LEDs 12. The LEDs can be arranged on a circuit board (not shown), for example, and associated accordingly with the display elements 21-28. The information display may be comprised by an electrical appliance, in particular an electric toothbrush, a television, a (mains-operated and/or battery-operated) monitor, a handheld electrical appliance, such as a drill, a mobile telephone, a PDA, a remote control, a digital camera, or the like.
The display panel or the information display may also form a component of an instruction and/or information sign or an electric switch.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “10 μm” is intended to mean “about 10 μm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
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