Display for Braille tablet

Disclosed is a tablet with an improved Braille display. The Braille display employs a pin array that allows for the selective use of either six or eight pin cells. This is accomplished by turning off or on a pin pair adjacent to each cell. The spacing of the pins also allows capacitive sensors to be located adjacent to each Braille cell. These sensors are used to determine the location of the user's finger upon the display. The pin spacing further allows geometric shapes to be generated in additional to text.

TECHNICAL FIELD

This disclosure relates to a display for a Braille tablet. More particularly, the present disclosure relates to various displays with an improved ability to locate the position of a user's finger upon the display.

BACKGROUND OF THE INVENTION

Braille displays are well known in the art. These devices allow the visually impaired to perceive individual Braille characters via tactile pins that can be selectively raised and lowered. These pins are arranged into an array consisting of a number of cells. Each cell, in turn, typically consists of six pins. Braille displays are adapted to be connected to a computer, or similar electronic device, to allow a visually impaired individual to perceive textual information. Often times, this information is present upon a screen. For this reason, Braille displays are refreshable and allow new rows of information to be continually presented to the user. Although Braille displays most often display textual characters, the pins can be used to generate geometric shapes. Braille displays may optionally include a keyboard to allow the user to input text. This may be a standard QWERTY keyboard or a dot type keyboard. Dot type keyboards feature keys that correspond to the individual dots of a Braille character. Regardless of the type utilized, the inputted text can be entered into a computer memory for subsequent retrieval. The inputted text can also be presented upon the display. Cursor router keys may be included within the keyboard to allow the user to insert text into a particular location upon the Braille display.

Braille displays frequently include individual cells featuring a six pin array, consisting of two columns of three pins each. Each of the pins forms a dot in the Braille character There are sixty four possible character combinations for an individual six pin array. An individual cell can be used to represent an individual letter, a digit, a punctuation mark, or even a word. Some Braille displays alternatively employ an eight pin array in lieu of a six pin array. Eight pin arrays allow the encoding of a greater number of symbols. For example, the lowermost pins in an eight pin array can be used to differentiate between lower case and upper case characters. Eight pin arrays, for this reason, are often used to display more formal writing, such as academic texts.

Various efforts have been made throughout the years to improve the functionality of Braille displays. For example, U.S. Patent Pub. 2013/0321302 to Naccache discloses a device for keying in Braille data and a corresponding computer program. The device includes a touch sensitive surface and is configured to detect a plurality of pressures. The plurality of pressures serve to form different Braille characters. An image can be constructed from the points associated with the plurality of different pressures.

Additionally, U.S. Patent Pub. 2015/0125831 to Chandrashekhar discloses a handheld electronic device with a tactile pin array. The device comprises a set of cameras that can capture an image. The image is thereafter processed and used to output a three dimensional representation of the image on the pin array. This allows one to recognize objects and obstacles in the area in front of the device. It also allows for navigation capabilities, facial recognition, and various input/output means.

An additional tactile display is disclosed by U.S. Patent Pub. 2015/0379895 to Chari. The display of Chari provides a representation of a graph or other image generated by a graphic device for visually impaired users. The display includes a frame assembly with hollow shaft chambers that are perpendicular to a number of hollow actuator members. Drive shafts are received within the hollow shaft chambers. Each drive shaft can be moved up and down via cams.

Although the background art contains several examples of tactile display constructions, they all suffer from common drawbacks. Namely, the displays of the background art fail to allow users to selectively use either six or eight pin cells. Nor does the background art disclose a display that can effectively display both Braille characters and Braille graphics. Known Braille displays also lack a means for accurately and conveniently tracking the position of the user's finger over the display. The improved Braille display of the present disclosure is aimed at overcoming these and other deficiencies present in the background art.

SUMMARY OF THE INVENTION

The present disclosure relates to the tablet with an improved Braille display.

One advantage of the present display is realized by providing a pin pitch that permits the selective use of either six or eight pin arrays.

A further advantage is realized by providing a pin arrangement that can display both individual Braille characters as well as Braille graphics.

The pins of the display are advantageously positioned to allow capacitive sensors to be placed immediately adjacent each Braille cell.

The positioning of capacitive sensors adjacent to the Braille cells allows the position of the user's finger to be detected and tracked.

Still yet an additional advantage is attainted by including a physical button that when depressed allows the user to move a cursor to a location adjacent to the user's finger on the display.

A further advantage is realized by creating a space between adjacent Braille cells to accommodate a number of capacitive touch sliders.

Various embodiments of the invention may have none, some, or all of these advantages. Other technical advantages of the present invention will be readily apparent to one skilled in the art.

DETAILED DESCRIPTION OF THE DRAWINGS

The present disclosure relates to a tablet with an improved Braille display. The Braille display employs a pin array that allows for the selective use of either six or eight pin cells. This is accomplished by turning off or on a pin pair adjacent to each cell. The spacing of the pins also allows capacitive sensors to be located adjacent to each Braille cell. These sensors are used to determine the location of the user's finger upon the display. The pin spacing further allows geometric shapes to be generated in addition to text. The various features of the present disclosure, and the manner in which they interrelate, are described in greater detail hereinafter.

Braille Tablet with Asymmetrical Pin Pitch

FIG.1illustrates a Braille tablet20with a refreshable display22. Display22is formed from an array of Braille pins24that are positioned across an outer face26. A number of individual pins28form part of a larger Braille cell34and can be selectively raised or lowered to generate a Braille character. This can be accomplished via any of a variety of known technologies; such as biomorph reeds, electromagnetic actuators, or piezo mechanisms. As illustrated, pins28are positioned along both X and Y axes. With continuing reference toFIG.1, it can be seen that a series of pin pairs32are oriented along the Y axis. Each pin pair32is positioned adjacent to a Braille cell34. Pin pairs32preferably consist of two side-by-side pins28. In accordance with the disclosure, each pin pair32can either be added to or removed from an adjacent Braille cell34to thereby generate either a six or an eight pin cell (36or38).

As is known in the art, each cell34, is used to generate a corresponding Braille character. For example, cell46inFIG.1is displaying the letter “D.” By refreshing display22, a user can successively read a series of characters, and thereby read text appearing on a computer screen. In accordance with the disclosure, display32can generate characters consisting of either a six pin array36or an eight pin array38. This is accomplished by the user selectively turning off or on an adjacent pin pair32. As used herein, a pin pair32is “off” when the pins are in a lowered orientation and are “on” when in a raised orientation. A six pin cell36can be generated by turning “off” an adjacent pin pair32, and an eight pin cell38can be generated by turning ‘on” an adjacent pin pair32. Whether the user wishes to generate information employing the six or eight pin array (36,38) will depend upon the particular application being employed. For example, six pin arrays can be used to convey information found on most websites, whereas academic literature often employs eight pin arrays.

In a further improvement to display22, the spacing of pins28across the face26is asymmetrical (i.e. non-uniform). In particular, the spacing between pins28along the Y axis (indicated at42) are generally uniform with all the vertically arranged pins28being equally spaced from one another. However, the spacing of the pins along the X axis (indicated at44) is not uniform. In particular, space44forms an alleyway between the adjacent cells34along the X axis (i.e. the horizontally arranged pins). This alleyway44has a spacing that is greater that the corresponding spacing42of the pins along the Y axis. s described below, alleyway44allows for capacitive sliders to be positioned upon display22. It has been found that this asymmetrical spacing is advantageous as it allows for both the display of six or eight pin cells (36,38) in addition to Braille graphics48. As illustrated inFIG.1, Braille graphics48are images or shapes that are generated by a corresponding number of pins28within display22. The non-uniform nature of the pin pitch allows both characters and graphics to be generated in a single display. However, the asymmetry may require a conversion to maintain the proper aspect ratio for certain geometric shapes.

Braille Tablet with Capacitive Touch Sliders

The present disclosure also relates to a Braille tablet with capacitive based sensors formed within the face of display. These capacitive sensors can by employed by the user to conduct any of a variety of functions. In one embodiment, the capacitive sensors are placed immediately adjacent each of the Braille cells and function as cursor router keys. They can also be used to track a user's fingers across the face of the display and thereby monitor the user's progress in reading a document. Incorporating the sensors into the face of the display is beneficial as spacing is critical in tablet displays and room for physical keys is limited.

In the preferred embodiment, display22is formed, at least partially, from a double sided printed circuit board (“PCB”)52.FIGS.2and3illustrate the underside of the PCB52. In the depicted embodiment, PCB52is formed from two layers of FR-4, which is a glass-reinforced epoxy laminate, that are bonded together. As depicted, the outer layer52(a) forms face26of the display and inner layer52(b) forms the inner surface53. Various electrical components can be soldered onto inner surface53of PCB52. Non-plated through holes50are also formed through the doubled sided PCB52to accommodate placement of individual pins28of display22. Notably, the outer surface of the PCB52is exposed to the user and forms a face of26the display. The use of the PCB52as the outer surface26avoids the need to register an outer cover with holes50. A microprocessor54is associated with tablet20and is in electrical communication with PCB52.

With continuing reference toFIGS.2and3, a series of capacitive, metallic strips56are positioned across the an inner surface53of PCB52. In the preferred embodiment, each strip56is formed from a series of shorter sub-strips that are bridged together by a series of resistors57. Resistors57allow the sub-strips to function as one large capacitive sensor56. These elongated strips56span the length of display22. Each strip56is positioned immediately below a corresponding alleyway44in display22. This ensures that each strip56is located adjacent to an associated Braille cell34. In the preferred embodiment, each strip56is positioned to the left of an associated Braille cell34. Capacitive strips56react to the charge in user's finger as the user touches the exposed surface26of display22. More specifically, a circuit is completed as the user touches surface26immediately above an associated capacitive strip56. Each layer of the PCB (56aand56b) acts as a dielectric material to create this capacitive circuit. The thickness of the upper, exposed layer56(a) of the PCB52can be selected to optimize the touch sensitivity. Capacitive strips56will register a user's touch anywhere along their length and are therefore referred to a “touch sliders.” Drive lines55are used to interconnect adjacent strips56.

Strips56allows the X-Y position of a user's finger to be detected when placed within the alleyway44adjacent a particular cell34(FIG.1). As the circuit is completed, microprocessor54executes instructions to associate the X-Y finger position with a particular cell34upon display22. Microprocessor54will make this determination while taking into account whether display22has been configured for a six or an eight pin array. In this regard, strips56can be used to monitor the progress of a user's fingers across display22, as would occur as the user is perceiving or “reading” the displayed Braille characters.FIG.6Billustrates a user's fingers progressing along display22. The microprocessor54would be employed in determining both the direction and rate at which the user's hands were progressing across the display. The top area of display22could then be refreshed in time for the user to sense additional lines of text. This feature would essentially allow the “pages” of a Braille text to be automatically turned as the user progresses through the material.

Another application of the strips56would be to allow the user to indicate where in the display to move a cursor. This may be used if the user is employing the notetaker function of tablet22. As illustrated inFIG.6A, tablet20may include a series dot-type keys64and a space bar66for the purpose of entering Braille characters into display22.FIG.6Eillustrates a user entering information via keys64. If the user wishes to place a cursor at a particular location within display22, the user would move the cursor by depressing space bar66along with touching an alleyway44adjacent a cell34of interest (FIG.6D). This action signals microprocessor54that the user wishes to move the cursor to the identified location upon display22. Alternatively, it may signal that the user wishes to interact with the associated Braille cell34in some other manner. For example, this feature could allow users to perform tasks such as copying, pasting, selecting, and/or editing functions. Using the display based, capacitive sensors in this manner avoids the need for peripherally located cursor router keys that can be challenging for some users.

Pin Blocks and Weighted Pins

FIG.5illustrates a block58housing a series of eight pin cells38. A similar bock (not shown) could be utilized for a series of six pin cells. Block58is formed as one modular unit. This allows all the pins28to be removed, replaced, or serviced as a discrete unit.FIG.4illustrates a weight62that can be positioned about the stem of each pin28. These weights62lower center of gravity of each pin28. This, in turn, allows the pins28to be more easily installed via a conventional vibration table.