Abstract:
A display device which displays image information in a form perceivable by a blind person. For this purpose, the display device has a plurality of areally arranged elements ( 1 ), which are individually actuatable, and an actuation device for actuation of the elements ( 1 ), whereby through the elements ( 1 ), electronic image information ( 7 ) fed into the evaluation device ( 16 ) is tangibly represented through the elements ( 1 ). The actuator elements may be arranged areally on a flexible substrate ( 13 ), which are individually actuatable, whereby through the actuator elements ( 11 ), vibrations and/or heat and/or electrical impulses can be generated.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of priority under 35 USC § 119 to German Patent Application No. 100 42 949.1, filed Aug. 30, 2000 and German Patent Application No. 100 42 950.5, filed Aug. 30, 2000, the entire contents of which are incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a display device which is especially suited for blind persons. In order to enable blind persons to also be able to read, the so-called Braille system of writing was developed where figures and numbers are represented as coded patterns. Small stampings for example on coins or in a book are tangible for blind persons and can consequently be comprehended. With special typewriters for the blind, individually written characters are first integrated in a line before a perforation or stamping of a substrate, which as a rule consists of paper, takes place. 
     In the meantime, with an almost complete permeation of the working world by electronic devices such as computers, blind persons are constantly confronted with the problem of not being able to comprehend the content on video screens. Particularly, FIGS. and numbers can be communicated through Braille in connection with the use of special accessory devices, but graphic representations, such as, for example, diagrams or tables, are now as before incomprehensible and cannot be inputted. 
     In addition, it is not possible to communicate to a blind person an image of their environment by means of Braille since this too requires a graphic representation. 
     SUMMARY OF THE INVENTION 
     One objective of the present invention is thus to propose a display device that makes it possible to make electronic image information normally represented on a video screen and comprehensible through the human sense of vision or the image of the environment comprehensible for the blind as well. 
     The objective is accomplished by a display device with a large number of areally arranged elements, i.e., elements arranged in an area of a surface on the device, preferably a substantially flat surface, which can be actuated individually, and an actuation device for actuation elements, whereby electronic image information fed to the actuation device is tangibly represented through the elements. Moreover the objective is accomplished through a display device with a large number of actuator elements areally arranged on a flexible substrate which are individually actuatable, whereby vibrations and/or heat and/or electrical impulses can be generated through the actuator elements. 
     The mode of operation of the actuator device is based upon the physiological fact that the finger pads and other specific skin regions react especially sensitively to micro-vibrations and heat. The scanned results are retained in short term memory owing to which, after a learning phase, the possibility arises of compiling an overall image of the individual readings in the brain. A flexible execution of a display device of the invention can be installed on unobtrusive places on the skin, and it is particularly suitable if, for orientation in an unfamiliar environment, a display apparatus should be carried along for a mobile orientation system. 
     Advantageously, the elements are arranged in a matrix. Even complex graphic image information can be represented comprehensively or tangibly through small matrix elements with a corresponding size of the overall matrix. In various configurations of the invention, the elements generate vibration, heat or electrical impulses, for example micro-discharges. In a further improvement, the frequency of the vibrations can be controlled in an especially advantageous configuration, representation possibilities are combined. In this way, additional information, for example the three dimensional properties of the objects represented or color differences can be represented. Making an input possible through an input device with a great number of areally arranged sensor elements, which are individually readable, and an evaluation device for evaluating the information of the scanned sensor elements is advantageous, whereby through the input device, an image generated by mechanical contact with the sensor elements is convertible into electronic image information. Sensor elements are in this way simply realized in that the matrix elements are additionally outfitted with sensory properties. 
     In a configuration especially advantageous for work with computers, the display device is supplemented with a sign input device which consists of a known Braille system input unit, a loudspeaker and function keys. When using the display device as an electronic book, the display device is provided with a read-in device which can read in conventional books through a camera or for example a scanner. Furthermore, it is possible to provide a device for reading in electronic data carriers, for example diskettes or CD ROMs. By supplementation with further functional units, the display device can be operated as an independent system. 
     Another special read in device is to be designed for receiving image information from the environment. By a combination with an image recognition system and a flexible construction of a display device of the invention, a portable orientation system is realizable. 
     In constructing the display device with a flexible substrate, the display device can be positioned at the most varied of sites, for example, unobtrusively on the back, the neck or on the forehead. There specially designed caps, hats or headbands are conceivable, whereby the display device fastened thereupon lies directly on the forehead. Since the display device constantly lies on the skin, it is advantageous if a skin tolerable material is selected as a substrate material, for example medical silicon. If the casing of the actuator elements is constructed suction cup-like, an especially good contact between the actuator elements and the skin arises owing to the suction on the skin, and therefore an especially good perception. 
     A display device of the invention is advantageously worn on a part of the body at which the density of nerve endings is as great as possible. In any case, it makes no sense to arrange a display device with a high resolution on a site on the body with a low number of nerve endings. 
     Further particularities and configurations of the invention are indicated in the description of the preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG. 1 shows a combined display and input device which is equipped for use on a computer with function buttons and a loudspeaker, 
     FIG. 2 depicts a flexible display device in a schematic representation, and 
     FIG. 3 illustrates the configuration of the casing of an actuator element as a suction cup, likewise in schematic representation. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, the invention is next explained below on the basis of embodiments. 
     In the embodiment represented in FIG. 1, the display device is realized as a matrix. 
     The matrix has a large number of elements  1  which are separated from one another by insulation frames  2 . The elements are individually and cyclically controlled as is basically known in connection with video screens. One objective of the insulation frames consists in separating the elements from each other such that an individual actuation is ensured without for example vibrations or heat extending into neighboring elements. In order to assure good recognizability, it is important for the properties of each individual element to be controllable separately and independently from other elements. The separation of the matrix elements is electrical as well as mechanical and thermal. In relation to the actuation of thermal properties, it is important that the insulation frames also have a small thermal capacity so that rapid temperature changes are possible. The resolution of the display device is determined by the dimensioning of the matrix elements  1  as well as by the construction of the insulation frame  2 . 
     The matrix elements  1  are, as already explained, actuatable in several characteristics. For generating heat, an infrared sensor comes into consideration here, a voltage sensor can generate electrical impulses and for generating oscillations, piezo elements as well as micromechanical or magneto-strictive elements are usable. 
     The various image information is now imaged in that the nerves of the finger sense the stimuli arising, namely thermal, mechanical and/or electrical with different apertures of the surface touched when sliding over the active matrix elements. In this way, very realistic, almost three dimensional images can arise in the brain. The simplest method is the generation of image information through mechanical oscillations of the elements. The other methods require more exercise and are dependent upon external temperature and humidity as well as the mental constitution of the user. The combined solution has the advantage that at the same time several nerve cells that are competent for different stimulus recognitions are addressed, and one can, in this way, obtain a better resolution of graphic information. Through the different types of stimuli, various contours as well as various shapes and color tones can be transmitted to the user. 
     The objective of the display device lies in transforming electronic image information  7  and actuating the elements such that an “image” which is interpretable for the user is generated on the matrix. Since perceptibility is individually variable, the processing options of the actuation device  6  is adjustable. 
     A block with function keys  3  and an input unit  4  for Braille script is provided as an input device. By laying the fingers on the input fields of the input unit for Braille script, coded signs can be read by the device and be converted into figures and numbers by an OCR module. The display takes place through the previously described display device. The processing options of the actuating device  6  can be adjusted especially through the function keys  3 . 
     A loudspeaker  5  is provided as a further display device. 
     Further possible applications for the display device consist in the use as a TV video screen or even in connection with a video camera as an “eye” in normal life. With the last mentioned application, it is advantageous to use two cameras so that when using the appropriate software, which, for example, undertakes contour transformation and contrast alteration, even three dimensional images can be generated. 
     The elements  1  may also have sensory properties for sensing mechanical contact and generating output signals which are transmitted to an evaluation unit  8  for generating electronic image information  9  based on the output signals. The electronic image information  9  generated by the evaluation unit  8  defines an image created by the mechanical touching. 
     In the embodiment represented in FIG. 2, the display device is realized as a matrix with a flexible support  13 . The matrix has a large number of actuator elements  11 , which are separated from one another by casings  12 . The actuator elements are individually and cyclically controlled, as is chiefly known from video screens. The objective of the casings among other things consists in separating the actuator elements  11  from each other such that an individual actuation is assured without, for example, vibrations or heat being able to extend to neighboring elements. In order to assure a good recognzability, it is important for the properties of each individual actuator elements to be actuatable separately and independently of other actuator elements. The separation of actuator elements  11  in the matrix is electrical as well as mechanical and thermal. With reference to the actuation of thermal properties, it is important that the casings also have a small thermal capacity so that rapid temperature changes are possible. The resolution of the display device is determined by the dimensioning of the matrix elements  11 , the construction of the casings  12  as well as the density of the nerve endings at the place in the body where the display device is installed. 
     The actuator elements  11  are actuatable in several properties. For generating heat, an infrared sensor comes into consideration in this connection. A voltage sensor can generate micro-discharges, and for generation of oscillations, piezo elements as well as micromechanical elements or magneto-strictive elements are usable. 
     The material of a flexible support  13  should either have air-permeable properties, or interstices should be left free between the actuator elements  11  in order not to hinder skin respiration during several hours of wearing time. The density of the actuator elements is correspondingly selected in harmony with the nerve distribution and the stimulus resolution possibilities of the skin parts selected for wearing. 
     Various modes of actuation are possible for mode of operation of the display device. In one actuation variant, all actuator elements  11  are simultaneously actuated. In another variant, individual image elements, for example also letters, are transmitted one after the other with adjustable time intervals. Which mode is preferred depends upon the information to be represented as well as upon individual preferences and opportunities of a user. 
     An actuation device  14  is connected with the display device. Information  15  to be represented is transmitted to the actuation device  14 . The objective of the actuation device  14  now lies in transforming electronic information  15  and actuating the actuator elements  11  such that an “image” which is interpretable for the user is generated by the actuator elements  11  of the display device. Since perceptive capacity is individually variable, processing options of the actuator device  14  should be adjustable. 
     In an advantageous application of the display device of the invention, the information  15  contains data on the environment of the user of the display device. For example, an image recognition unit with optical cameras is connected in series in front of the display device  14 . The cameras receive objects in the environment, an image recognition unit recognizes the objects and transmits the information to the display device  14 . This transforms the information such that the actuator elements  11  are suitably actuated. 
     Through the combination of actuator elements which emit vibrations with those which generate heat or electrical impulses, the resolution can be basically increased or additional information can be transmitted. Further parameters for generating display information are the frequency and amplitude of the vibrations or the heat or the electrical impulses. Thus, in addition to contours of objects in the environment, their color can also be communicated to the user. In addition to the presence of objects, their distance from the user is representable. The brain can subsequently generate a three dimensional image on the basis of the information given. 
     How the suction cup-like configuration of the casings  22  can be constructed is represented in FIG.  3 . The actuator elements are arranged matrix-like, whereby the distance between the matrix elements  11  is adapted to the density of nerve endings of the skin. The size of the casings  22  can be selected depending upon the distance between the actuator elements  1 . The casings  22  in the embodiment depicted widen conically upwardly the typical suction sup shape arises. The casings  22  are advantageously manufactured of silicon, just like the flexible support  13 . 
     Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.