COMPUTER INPUT DEVICE

Abstract: The invention relates to a computer input device comprising an elongated housing having at one end rotary means capable of being moved relative to a substrate, and optical detection means for detecting the movement of the rotary means, said detection means being disposed inside said housing, wherein the rotary means comprises at least two rotary members arranged in a stacked configuration and that a first rotary member displays a surface of high friction material for contact with the substrate and the second rotary member displays an optical detection surface for optical detection of the surface movement. The first rotary member can rotate against the substrate and transform this rotation to the second rotary member. The rotation of the second rotary member is then detected by the optical detection means. Hereby, both the requirements concerning high friction against the substrate of the first rotary member and the optical detection surface of the second member have been solved.

Description: COMPUTER INPUT DEVICE The present invention relates to a computer input device comprising an elongated housing having at one end rotary means capable of being moved relative to a substrate, and optical detection means for detecting the movement of the rotary means, said detection means being disposed inside said housing. A computer input device, such as a computer mouse, having optical detection means are known in the art, e.g. from WO 94/22071 or US 5,288,993. Computer input devices having elongated housings in the shape of a computer pen are also known from i.e. EP 0 413 606. The idea behind the computer pen is to simulate the use of a normal writing pen. However the drawbacks of these pen structures are numerous. They are bulky in their design and the minimum allowed diameter of the ball is unacceptably large so that the intended use pattern cannot be achieved. In relation to present progressive and innovative developments in the computer pen design there is currently being developed a new and improved optical detection method, paving the way for a very small size of the ball. This results in a slim pen housing making it possible to use the computer pen in a use pattern similar to a normal writing utensil. The movement of the ball is detected by optical detection means by detecting the change in surface structure of the ball. The ball is therefore provided with a surface structure insuring good optical detection signals corresponding to the movement of the ball. The ball is therefore preferably made of steel or similar material. In order to ensure that the movement of the ball corresponds to the movement of the computer pen a certain amount of friction is needed between the ball and the substrate against which the ball is moved during the use of the computer input device. These two requirements to the surface of the ball are somewhat contradictory, and the object of the present invention is to provide a solution by which there is ensured a satisfying amount of friction between the ball and the substrate whilst a convenient surface structure for optical movement detection is maintained. The present invention discloses a computer input device of the initially mentioned kind, wherein the rotary means comprises at least two rotary members arranged in a stacked configuration and that a first rotary member displays a surface of high friction material for contact with the substrate and the second rotary member displays an optical detection surface for optical detection of the surface movement. By the present invention the two above-mentioned contradictory requirements for the rotary means have been overcome. The first rotary member can rotate against the substrate and transform this rotation to the second rotary member. The rotation of the second rotary member is then detected by the optical detection means. Hereby, both the requirements concerning high friction against the substrate of the first rotary member and the optical detection surface of the second member have been solved. In an embodiment of the invention the first rotary member is made of rubber and that the second rotary member is made of steel with coating for facilitating optical detection of its rotation. Hereby, the two rotary members are optimised according to their functions in an inexpensive manner in the computer input device according to the invention. The second rotary member could be made of steel, plastic or the like and given a coating of light reflecting material. In the first preferred embodiment the optical detection surface of the second rotary member comprises a coating of TiN plasma material for optical detection of the surface structure. By this TiN plasma coating is optimal in order to the creation of speckles on the surface for optical detection, whereby a rotary member having a very small diameter can be provided. Alternatively, the optical detection surface of the second rotary member displays a pattern of randomly configured spots in contrast colours. This embodiment is an inexpensive solution for rotary member having a large diameter. In the preferred embodiment the computer input device according to the invention displays a first and second rotary members consisting of a first, outermost ball and a second, innermost ball, respectively. The first and second ball are preferably aligned along the centre axis of the elongated housing, whereby a housing having dimensions similar to a pen or similar writing utensil can be provided. In a preferred embodiment, the diameter of the first ball is larger than the diameter of the second ball. By providing a second ball of a smaller diameter a low friction of rotation is ensured for the first ball. In another preferred embodiment of the invention, at least the first ball is supported by a bearing. Furthermore, the accumulated friction of the bearing and between the balls is lower than the friction between the first ball and the substrate. The bearing is preferably made of a number of steel balls embedded in polymeric material having a low coefficient of friction. Hereby slip in the assembly of the rotary means can be prevented and the detection can be detected accurately and in correspondence to the relative movement of the computer input device, as the rotation velocity of the surface of the first and the second ball according to this embodiment of the invention will correspond to the velocity of the computer input device relative to the substrate. The invention is in the following explained in more detail with reference to the accompanying drawings, in which: fig. 1 is a view of a computer input device designed as a computer pen, and fig. 2 is a detailed view of the detection means of the computer pen. In figure 1 a computer input device can be seen. The device is shaped like a pen or similar writing utensil. It comprises an elongated housing 1 with rotary means 2 in one end of this housing 1. As can be view in detail in figure 2, said rotary means 2 cooperate with the optical detection means 3 for the detection of the movement of the computer pen in relation to a substrate, such as a table, a writing desk or the like. The housing 1 is provided with click-bottoms 6 ergonomically arranged on the side of the housing for operating the computer input device. The rotary means 2 comprises a first ball 4 and a second ball 5. The first ball is made of rubber or similar material creating a high friction between the ball 4 and the substrate and between the first ball 4 and the second ball 5, so that the rotation of the first ball 4 is transplanted to the second ball 5. By ensuring a good frictional contact between the two balls 4, 5 a similar peripheral surface velocity of the two balls are ensured and the two directions of rotation are altered. The second ball 5 can be prepared with a coating of TiN in order to optimise it for optical detection of the surface movement of the ball 5. Detecting the speckles in the surface structure has proven a reliable and effective manner of detecting the direction and the velocity of the rotation of the ball 5. The ball 5 is preferably made of steel or the like with a coating of a high light reflecting material, such as TiN. However, other surface structures and corresponding detection means and detection methods can also be used. For example, the surface could also be prepared for magnetic detection and a suitable coating could be provided for this purpose if necessary. Alternatively, the ball could be provided with a basic colour and randomly distributed spots in a contrast colour. By the invention it is realised that either one or both the balls 4, 5 alternatively could be replaced by a rotary cylinder or a rotating wheel. Furthermore, it is realised that one or more rotation transmitting rotary members can be inserted between the first and second rotary members of the computer input device according to the invention as set forth in the accompanying claims.

Claims: PATENT CLAIMS: 1. Computer input device comprising an elongated housing having at one end rotary means capable of being moved relative to a substrate, and optical detection means for detecting the movement of the rotary means, said detection means being disposed inside said housing, characterised in that the rotary means comprises at least two rotary members arranged in a stacked configuration and that a first rotary member displays a surface of high friction material for contact with the substrate and the second rotary member displays an optical detection surface for optical detection of the surface movement. 2. Computer input device according to claim 1, characterised in that the first rotary member is made of rubber and that the second rotary member is provided with a coating for facilitating optical detection of its rotation. 3. Computer input device according to any of the claims 1 or 2, characterised in that the optical detection surface of the second rotary member comprises a coating of TiN plasma material for optical detection of the surface structure. 4. Computer input device according to any of the claims 1 or 2, characterised in that the optical detection surface of the second rotary member displays a pattern of randomly configured spots in contrast colours. 5. Computer input device according to any of the previous claims. characterised in that the first and second rotary members consist of a first, outermost ball and a second, innermost ball, respectively. 6. Computer input device according to claim 5, characterised in that the first and second ball are aligned along the centre axis of the elongated housing. 7. Computer input device according to claim 5 or 6, characterised in that the diameter of the first ball is larger than the diameter of the second ball. 8. Computer input device according to any of the claims 5 to 7, characterised in that at least the first ball is supported by a bearing, and that the accumulated friction of the bushing and between the balls is lower than the friction between the first ball and the substrate.

Inventors: JENSEN JOERGEN KORSGAARD, JENSEN, JOERGEN, KORSGAARD
Applicants: JENSEN JOERGEN KORSGAARD, KANITECH A S, JENSEN, JOERGEN, KORSGAARD, KANITECH A/S
Application year: 1999
Main classification: G06K11
IPC codes: G06F3