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ERGONOMIC POINTING DEVICE
TECHNICAL FIELD
This invention relates to pointing devices for entering commands into a computer or other interactive system, and 5 more particularly, to a trackball-type pointing device that is ergonomically designed, and in a preferred embodiment, is particularly well suited for children.
BACKGROUND OF THE INVENTION 10
Pointing devices for entering commands into a computer or other interactive system are well known in the art. Some pointing devices include a rotatable ball and one or more depressible keys, sometimes referred to as buttons. Electronic encoders sense rotation of the ball, and generate a 15 signal indicative of the ball's rotation to control movement of a cursor on a screen of the computer. Depressing the keys permits a user to enter various commands into the computer, based on the location of the cursor and the software that is being used. 20
In a mouse-type pointing device, the rotatable ball extends from a bottom surface of the pointing device for contacting a work surface, such as a tabletop. The movement of the pointing device across a work surface causes rotation of the ball and the desired movement of the cursor on the screen.
In a trackball-type pointing device, the rotatable ball extends from a top surface of the pointing device and the ball is moved through contact with a user's hand. The movement 3Q of the trackball against the hand causes the desired movement of the cursor on the screen.
Many of the currently available pointing devices are designed for adults. As such, a child may have difficulty positioning the cursor and then depressing the keys; a child 35 may not be able to control the movement of the pointing device with the level of precision typically required to accurately position the cursor; or a child may not be able to reach the desktop to move and use the pointing device. A need therefore exists for a pointing device that is easy for 40 children to use.
SUMMARY OF THE INVENTION
In a preferred embodiment of the present invention, an ergonomically designed trackball-type pointing device is 45 provided, having a substantially elliptical housing. The housing has a first gripping area for a left hand of a user and a second gripping area for a right hand of the user. The gripping areas are provided with texture, for example, raised ridges, to provide a tactile and visual cue for placement of 50 the user's hand, and to enhance secure contact with the user's hand.
In a preferred embodiment for use by children, a relatively large ball is contained in the housing, a portion of the ball extending upward from an upper surface of the housing. The 55 ball is sized to optimize manipulation of the ball by users having a hand size in the range of a 5th percentile 2 year old North American child to a 95th percentile 6 year old North American child. The ease with which the ball may be rotated by a user is set to provide sufficient resistance to accom- 60 modate the motor skills of a child aged 2-6. A button is located in a front region of the housing for entering commands into a computer, the location, size and shape of the button being configured to optimize both the target area and activation of the button. 65
In a preferred embodiment of the present invention, the housing slopes in an upward direction from a front region of
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the housing to a rear region of the housing, to orient the product to the user. A bottom surface of the housing has feet to stabilize the pointing device and thereby allow a user to comfortably and accurately use the pointing device on a work surface or in the lap of the user.
The housing is further designed to ensure that the ball is captured and retained by the housing. As a result, users, particularly children, cannot easily remove the ball, thereby helping to ensure that the ball does not get lost or damaged, and that users do not place their hands or other objects in the pointing device. The housing is also configured to minimize the amount of dust and debris that may enter the housing via the clearance opening between the ball and housing. To further protect the printed circuit board (PCB) contained in the housing, a protective cover is provided that encases the PCB to form an encoder chassis assembly. The protective cover also shields the PCB from being handled when, for example, the pointing device housing is opened to clean the inner workings and surfaces of the pointing device.
All of the design features noted above work together in a preferred embodiment to provide physical and visual cues for a child user to orient, grasp, and use the pointing device in a manner that is suitable to a child's hand size, degree of fine motor coordination, and postural needs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front isometric view of a pointing device provided in accordance with a preferred embodiment of the present invention.
FIG. 2 is a right side elevational view of the pointing device of FIG. 1.
FIG. 3 is a bottom plan view of the pointing device of FIG. 1.
FIG. 4 is a top plan view of the pointing device of FIG.
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FIG. 5 is an illustration of the pointing device of FIG. 1 in use.
FIG. 6 is an exploded isometric view of the pointing device of FIG. 1.
FIG. 7 is a cross-sectional front elevational view of the pointing device of FIG. 1.
DETAILED DESCRIPTION OF THE
INVENTION
As illustrated in FIG. 1, a trackball-type pointing device 10 provided in accordance with a preferred embodiment of the present invention is ergonomically designed, and in a preferred embodiment, is particularly well suited for young children, aged 2-6. The housing 12 is substantially elliptical, the size and rounded edges of the housing 12 making it suitable for a user to position and use the pointing device 10 in his or her lap. In a preferred embodiment, as illustrated in FIGS. 3 and 7, a diameter 39 of a bottom surface 46 is 3.75-6.25 inches, which corresponds to the range of interthigh crest dimensions expected for a 5th percentile 2-year old. Similarly, diameter 41 of pointing device 10 is 3.75-6.25 inches, the particular dimensions of the bottom region of pointing device 10 being selected according to the targeted age group. In a preferred embodiment, diameter 39 is approximately 4 inches and diameter 41 is approximately 5 inches such that the pointing device is sized to be securely and comfortably held on the lap of a seated child aged 2-6. It will also be understood that the pointing device may be positioned on a work surface, such as a table or desktop. In order to ensure that the pointing device 10 is stable regard
