WO2000007078A2

WO2000007078A2 - Low profile micro encoder

Info

Publication number: WO2000007078A2
Application number: PCT/US1999/017395
Authority: WO
Inventors: Joseph Michael Allison
Original assignee: Tuoriniemi, Veijo, Matias
Priority date: 1998-07-28
Filing date: 1999-07-28
Publication date: 2000-02-10
Also published as: AU5248799A

Abstract

A low profile encoder providing electric signals representing rotational motion in two directions having a rotatable, generally cylindrical, motion-energy receiver. The outer rim of the roller has a predetermined quantity of cams mounted in predetermined order. The rotatable roller lies generally in horizontal position on an upper surface of a planar base. The planar base has predetermined quantity on sensing means mounted on an upper surface to meet the agitation of the cams. In a preferred embodiment the cams agitate two cantilever beams connected to stress responsive resistors located in the fulcrum of the cantilever beam. The cantilever beams have opposite mechanical movements. The rotation and direction is determined from the change of the resistance in the resistors. Other embodiment variations are explained in the description.

Description

LOW PROFILE MICRO ENCODER

Applicants: Veijo M Tuoriniemi, residing in New York, New York Joseph M. Allison, residing in Euclid, Ohio

FIELD OF INVENTION

This invention relates to encoders, especially encoders responsive to rotational motion. This invention senses changes in the angular position and velocity of an encoder shaft and converts the motion to electronic signals for use as input to a microcontroller.

BACKROUND OF THE INVENTION

This application claims priority from provisional application serial no 60/094,232 filed on July 28, 1998 and improves on provisional application serial no.60/058,934 filed September 15, 1997 hereby fully incorporated by reference.

Prior art encoders, responsive to rotational motion, use an encoder wheel to determine rotation and direction of rotation. Encoder wheel with associated light emitter and receiver is usually embedded in vertical position on a circuit board. This type of an encoder takes a lot of space and therefore is not practical to be used in small devices.

Prior art devices can move cursor on a screen, but in order to make selection user has to lift finger from cursor control or make selection by an other finger.

BRIEF SUMMARY OF INVENTION This invention discloses a low profile encoder having a rotatable, generally cylindrical motion energy receiver. The energy-receiving roller can vary in shape and form. E.g. variable roller diameter provides variable rotational speed depending from which part of the roller is touched and rotated. Roller can have threads or groves to improve touch and manage rotation. The outer rim of the roller have a predetermined quantity of cams mounted in predetermined order.

The rotatable roller lays generally in horizontal position on an upper surface of a planar base. The planar base has predetermined quantity on sensing means mounted on it's upper surface to meet the agitation of the cams.

In preferred embodiment the cams agitate two cantilever beams connected to stress responsive resistors located in the fulcrum of the beam. The cantilever beams have opposite mechanical movements. The rotation and direction is determined from the change of the resistant in the resistors.

OBJECTS AND ADVANTAGES

The object of the disclosed invention is to provide an encoder which can be fabricated onto a printed wiring board (PWB) containing other electronic components. The invention can be employed with several different hand-held devices such as portable telephones, hand-held

PCs, TV-remote controls and cameras.

One roller can be used to tune radio stations, roll a vertical list on a cellular telephone display or in other one-dimensional applications. The preferred embodiment comprises two closely positioned rollers, which can be moved simultaneously with one finger. Dual-rollers provide for a standard two-dimensional cursor control device. If desired, a third dimension roller can be added, spaced close to the other rollers such that all three rollers can be manipulated simultaneously using one fingertip.

The disclosed invention provides a small, very low profile, low cost cursor control. The device is simple, inexpensive to manufacture and has fewer parts than a conventional mouse. The disclosed cursor control device can be mass manufactured using a MOS process and automated methods. Processing circuitry, i.e. interface electronics between the sensor and data system can be assembled on the same circuit board along with the device.

Because of the sensitivity of the human fingertip, even the finest cursor movements are possible. Rollers can be made small and accurate. Both rollers can be moved by one finger at the same time. Operation is effective and fast.

Instead of rolling through long documents by using scroll bars on the side of the window, dual touch rollers can be used to move up, down and sideways. This invention makes sidebars unnecessary and gives the user more visual screen area. Pushing a designated switch makes the transformation from cursor control device to page moving device. Cellular telephone service providers are offering Internet services to customers. The market demands cursor control devices which can be used with cellular telephones. In order to use the Internet efficiently, cellular telephones need bigger screens and cursor control devices, which are easier to use. This development leads to diminishing keyboards and growing screens.

Eventually the screen will cover the front panel of the telephone and the keypad will be replaced with a graphical menu. A thumb operated dual-roller device with selection switch is practical to make selections on a display while holding the phone in one hand. In conventional TV remote controls, selections are made by using the arrow keys.

Usually, arrows are combined with a cross type wobble-plate. A conventional device is insensitive and relatively slow. A conventional remote control with keypad is impractical because there is not enough space for the many buttons needed for all of the functions. High definition digital TV will use a Windows -type operating system to control home entertainment devices including Internet, CD player, DVD-player, radio and amplifier. All devices will be controlled on a TV-screen by using a remote control and graphical interface on the screen. Controlling home entertainment devices will be much like using a windows program with select-bar and drop-down and pop-up menu's.

A dual-roller device will offer an accurate, smooth way to adjust volume and other features. A dual-roller with infrared or other wireless connection can provide a user-friendly remote control with needed mouse capability. A hand held remote control needs only a cursor control device and a select button to make selections on screen.

Hand held computers use Windows CE or similar graphical operating systems with touch screen cursor control devices. Touch screens are usually pressed with a stylus. The additional touch sensitive layer in front of the screen makes the screen look dark.

A dual-roller does not need a touch sensitive cover layer. The screen without additional layer looks lighter, has deeper contrasts and therefore is user-friendlier. Using a dual-roller cursor control device in a corner of a keyboard makes selection easy and fast. .

Laptop computers use touch pad cursor controls. These devices usually lack the sensitivity of a mechanically connected mouse. The cursor is difficult to place over an icon: it travels over the desired object so that, the user has to make several correctional movements before the right cursor position is reached. The touch panel also takes up valuable space on a portable computer keyboard. Touch panels also tend to be sensitive to dirt, moisture and oils. The ratio of the cursor speed to the roller speed is the speed transfer ratio. With the right control algorithm, the speed transfer ratio can be made variable and responsive to roller speed such that... The slower the user moves the roller, the smaller the transfer ratio gets, making it easy to home in on a target area. On the other hand, the entire screen can be quickly traversed simply by moving the roller quickly.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows an exploded view of a dual-axis encoder employing two cantilever beams with stress responsive resistors.

Figure 2 shows the upper view of an encoder having one cantilever beam and a stress responsive resistor.

Figure 3 a show the rotation cycle of the polygonal-end roller shown from the end of the roller. Cantilever beam is in a relaxed stage. Figure 3b show the rotation cycle of the polygonal-end roller shown from the end of the roller. Cantilever beam is in a pressed-down stage.

Figure 4a shows the resistance change when the roller is rotated in a first direction.

Figure 4b shows the resistance change when the roller is rotated in a second direction.

Figure 5 shows the upper view of an encoder having two cantilever beams and two stress responsive resistors.

Figure 6a shows the rotation of the polygonal-end roller with two cantilever beams.

Figure 6b shows an upper view of a cantilever beams in fig. 6a.

Figure 7a shows the resistance change for resistors 20a and 20b when the roller is rotated in a first direction. Figure 7b shows the resistance change for resistors 20a and 20b when the roller is rotated in a second direction.

Figure 8 shows an encoder having three pressure sensitive resistors in a perpendicular line against the roller shaft, under the polygonal end of the roller.

Figures 9a-9d show a rotation of the corner of the polygonal-end roller against pressure sensitive resistors.

Figure 10 shows three resistors of fig. 8, change in resistance, produced electric signals and data output. Figure 11a shows a meat grinder type cam set-up.

Figure l ib shows two overlapping resistors under cam in fig. 11a, change in resistance, produced electric signals and data output.

Figure 12a shows a roller with two pressure sensitive resistors mounted parallel under the polygonal end of the roller, polygonal end having the cams in predetermined order. Figure 12b shows two resistors agitated by the cams in predetermined order, change in resistance, produced electric signals and data output.

Figure 13 shows input and output electrodes under the conductive cams of the roller.

Figure 14a and 14b show a Hall effect device employed to measure movement in the end of the cantilever beam.

Figure 15 shows capacitance read out done by using a first metal plate in the end of the cantilever beam and a second metal plate on the base below the first plate.

Figures 16a and 16b show an optical encoder arrangement having one light emitter and one light detector. Figures 17a, 17b and 17c show an optical encoder arrangement having one light emitter and two light detectors.

Figures 18 shows an optical encoder arrangement having two light emitters and two light detectors.

Figure 19a shows an optical encoder having straight reflecting surfaces. Figure 19d shows an optical encoder having one-dimensionally convex surface.

Figure 19c shows an optical encoder having two-dimensionally convex surfaces.

Figure 20 shows a two-axis encoder device adapted to be used with a track ball

Figure 21a shows a two-axis encoder device adapted to be used with a mouse.

Figure 21b shows a two-axis encoder device mounted to a mouse housing. Figure 22 shows a two-axis encoder device adapted to be used with a cursor control device operated with a tongue.

Figure 23 shows a two-encoder device adapted to be used with a device being able to be hold over user's finger.

Figure 24 shows a two-encoder device adapted to move a tool to manipulate objects by telemanipulation in remote work site.

Figure 25 shows a two-encoder device adapted to be used with a camera to select and aperture and a shutter speed.

DESCRIPTION OF THE FIRST EMBODIMENT This application improves on provisional application "Single Touch Dual Axis Input

Device" serial no.60/058,934 filed 09/15/97, attached hereto and incorporated by reference. In figure 2 a touch roller 10 has a polygonal shape end 12. Cantilever beam 16 is micromachined out of single crystal silicon and it is part of the silicon base 17. A piezoresistor 20a is formed over the fulcrum 21 of the cantilever beam 16. Piezoresistor 20a can be e.g. a boron-doped region of silicon. The base 17 with the touch roller 10 is laying on a glass support 22.

OPERATION OF THE FIRST EMBODIMENT

Figure 3a shows the side 14 of the polygon resting parallel with a cantilever beam 16. The cantilever beam is in the position of minimum stress.

Figure 3b shows the rotation of roller 10. The edge 18 of the polygon first slowly presses the beam 16 down beginning from the end 23 of the cantilever beam 16. When the roller 10 is rotated further, the edge 18 of the polygon reaches the turning point 28. At the turn point the edge 18 is perpendicular to the cantilever beam 16.

Beyond the turning point 28 the edge 18 of the polygon has a shorter distance to travel to the release point 30 than it had from the end 23 of the beam to the turning point 28. Therefore further rotation of the edge causes a more rapid upward movement of the cantilever beam 16 than for the downward movement.

The stress responsive resistor 20 is placed at the fulcrum 21 of the cantilever beam where the maximum stress occurs. Bending of the cantilever beam 16 causes dimensional changes in resistor 20. The resistor 20 senses the bending of the cantilever beam.

In figure 4a the resistance R in the resistor 20 is described by a curve. Rotation cycles are shown on the x-axis. Elapsed time T and produced data bits are shown under the x-axis. In the beginning (1/x) the side 14 of the polygon is parallel to beam 16. When the polygon is rotated in a first direction the edge 18 of the polygon presses the end 23 of the cantilever beam. At first the resistance increases slowly up to the turning point 28. At the turning point 28 the edge 18 of the polygon is perpendicular to the beam and resistor 20 has its' highest resistance. From the turning point 28 the edge has a shorter distance to travel to the release point 30 than it had to come there from the end 23. Therefore when the edge is rotated beyond the turning point, the resistance in resistor 20 runs down more rapidly than it had run up. Resistance degreases until the edge releases from the cantilever beam surface and the beam is back to the non-tensioned state. Figure 4b shows the resistance curve when the roller is rotated in a second direction.

This change in resistance is a mirror image of the one produced by rotation in a first direction. In the beginning the edge of the polygon presses the beam from the contact/release point 30. The beam bends relatively fast in the downward direction and resistance increases rapidly. At the turning point 28 the resistance is the highest. Beyond the turning point the stress in the beam is relieved slower than it had been built up. In the end 23 of cantilever beam the edge releases the beam. In this non-tensioned condition the resistance is at its' lowest level. The electrical output signal from resistor 20 requires processing or conditioning before it can be used by a data system. This signal processing circuitry, which is between the sensor and data system, is called interface electronic circuitry (not shown).

Interface electronics sense the resistance change resistor 20 at two levels, first when the resistance increases to a predetermined high level and a second time at a predetermined low level.

The high level is reached near the turning point 28. At this high resistance level the threshold logic of the interface electronics passes the current. Passing the high resistance level produces an electronic signal that is stored as a data bit (1). A second data bit (0) is produced when a predetermined low resistance level is reached, when the cantilever beam is in the non- tensioned condition.

The longer distance between the edge contact point in the end of the beam to the turning point compared to the distance between the turning point and release point can be determined by measuring the traveling time of the edge.

Turning point 28 and non-tensioned level 23 are convenient phases to form corresponding data bits. Also intermediate resistance levels can be sensed and acted upon by threshold logic.

The direction of rotation, magnitude and frequency can be measured from the pattern of change in resistance on the resistor. The traveling time between the end of the beam to the turning point is longer than from the turning point to the release point. Non-tensioned condition measuring event 23 and turning point measuring event 28 produce two data bits (1,0 or 0,1) spaced closely in time the direction of rotation is determined by comparing the order of these two data bits. These signals can be used for calculating cursor movement or various other purposes in computer software applications.

The roller can have a select button under the shaft at the far end (not shown). Select button functions are similar to a right and a left button of a standard mouse. When the cursor is over a designated option area, pressing the far end of the roller can make the selection. The substantially flexible roller shaft is supported by shaft supports at three points. When the end of the roller is pressed down, the shaft bends at the middle support point. The middle support with its counterpart in the cover of the device also encloses the encoder electronics, protecting them from dust and dirt.

In a further embodiment of the cursor control device, the software is designed to respond to the speed of rotation by changing the speed of the cursor movement. The microprocessor has the immediate history of the rotation in memory. The speed of the rotation is used to accelerate the cursor speed on the screen. The relation can be direct or exponential.

The faster that the user rotates the roller, the relatively faster and broad the cursor movement is. When it is needed, the user can jump the cursor to the other side of the screen by one short fast roller movement. Rotating the roller slowly performs fine cursor movements. Slow rotation gives enhanced, more accurate, cursor control.

DESCRIPTION OF THE SECOND EMBODIMENT

Figure 5 shows an embodiment having two cantilever beams 16a and 16b. The cantilever beams 16 are at opposite sides of the polygonal end 12 of the roller 10. Stress responsive resistors 20a and 20b are formed in the fulcrum 21 of the cantilever beams. The polygonal roller lays on supports 22 above the beams. The shaft of the roller is centered in the space between the two beams.

In figure 6a and in the top view in figure 6b, the roller 10 is rotated in a first direction. The edge 18 simultaneously presses the first cantilever beam 16a (behind the beam 16b) from the end 23a of the beam and the second cantilever beam from the contact/release point 30b. The edge 18 travels across the beam surface and bends beam 16b down faster than beam 16a.

Resistance in resistor 16b increases faster and reaches the high level at turning point 28b.

Resistor 20a reaches the turning point 28a later. Beyond the turning points, resistance in resistor 20a decreases faster than the resistance in resistor 20b.

After the cycle, the edge 18 simultaneously leaves the first beam 16a at release point 30a and second beam 16b at the end of the beam 30. The result of the rotation is a series of two equal length analog signal waves having different phases.

When the edge is rotated, resistor 20b reaches the high resistance level 28 first, causing the interface electronics to produce a data bit (1). The comparative data bit on resistor 20a is low (0). Resistor 20a reaches the high level next and high data bit (1) is produced. The comparative data bit on resistor 20b is low (0). Simultaneous return of the cantilever beams to non-tensioned positions, results in a high (1), (1) data bit pair.

The direction of rotation is determined by comparing the order of data bit pairs produced by resistors between the shared non-tensioned condition. The following data bits are produced during a cycle when rotation is in a first direction: first output 20a 1 0 1 1 0 1 second output 20b 1 1 0 1 1 0

Figure 7b shows the resistance change of resistors 20a and 20b when the roller is rotated in a second direction.

The following data bits are produced during a cycle when rotation is in a second direction. first output 20a 1 1 0 1 1 0 second output 20b 1 0 1 1 0 1

The finest signals can be achieved from a analog signal by comparing the continuous rate of change in resistors 20a and 20b in different operational phases and determining the direction of rotation from the rate of change in data by software. An analog signal can be transferred to a digital data by using methods known in art. Instead of using two opposite cantilever beams and the same polygonal end to produce two equal length waves, which have different phase, another geometry can be used to move the sensors to get the same result. For example cantilever beams can be on the same side. In this case the polygonal end of the roller could be divided in two sections, each section having the corners in predetermined order agitating the designated cantilever beams in different phases.

DESCRIPTION OF THE THIRD EMBODIMENT

Figure 8 shows a low cost, reliable encoder to be used with a roller. Pressure sensitive resistors 32a-c are mounted on the surface of the support 22. Resistor 32a-c are pressure sensitive resistors, the resistance of which changes when pressure is applied. Resistors can be made out of conductive rubber or piezoresistive material. The roller 10 is laying on shaft supports 34a-c. The polygonal end 12 of the roller is above the resistors. The resistors are connected to the interface electronics through connectors 26. A durable wear and tear resistance layer (not shown) can be placed between the resistors and the roller to protect the resistors.

In figure 9a, the roller is in rest position, resistors 32a-c are not compressed and have their nominal resistance. In figure 9b the roller 10 is rotated and the edge 18 of the polygon presses the resistor 32c. When the roller is rotated further in figure 9c the edge presses resistor

32b and in figure 9d the resistor 32a. The interface electronics (not shown) senses the change in resistance and sends an electronic signal at a predetermined resistance level. The electronic signal is used to produce a data bit. Comparative data bits are produced on other lines.

Figure 10 illustrates the resistors 32, change in resistance, produced electric signals and data output.

A three-resistor sensor is used to form the following data bit pattern: first line output 1 0 0 second line output 0 1 0 third line output 0 0 1

The direction of the rotation is determined from the order the data bits are received and the magnitude of the movement is determined from the change in resistance. Frequency can be sensed from the time difference between bits.

Instead of using three resistors, two resistor can be used as a sensor. Two closely spaced resistors produce data bit pair (1) and (0) respectively. Like the first embodiment, the data bit pair is separated from the next pair by a longer period of corner travel time.

The direction of the rotation is determined from the order of the data bit pair (1,0) or (0,1). The magnitude of the movement is determined from the change in resistance. Frequency can be sensed from the time difference between data bit pairs. Figure 11a shows an improved polygonal end of the roller. Polygonal end is twisted along longitudinal axis to have a meat grinder shape. Shape provides smoother glide of the corner over the resistors.

In figure 1 lb two overlapping resistors having overlapping change in resistance are used to produce two overlapping electric signals resulting in three pairs of two digit data output.

DESCRIPTION OF THE FOURTH EMBODIMENT

Figure 12a shows an alternative arrangement for pressure sensitive resistors described in the third embodiment. The pressure sensitive resistors 32a and 32b are mounted in a parallel row with the roller shaft under the polygonal cams 36. When the roller is rotated, the cams 36 agitate the resistors 32 in a predetermined order. Resistor response is used to fill an arrangement of memory elements in computer memory. Figure 12b shows two resistors agitated with an array of cams in predetermined order, change in resistance, produced electric signals and data output

The following data bits are produced during a cycle in a first direction: first output 1 0 1 1 0 1 second output 1 1 0 1 1 0

The following data bits are produced during a cycle in a second direction, first output 1 1 0 1 1 0 second output 1 0 1 1 0 1

Having the resistors 32a-b in parallel position with the roller shaft 38, under the shaft and providing an array of polygonal cams has several advantages:

1. Resistors are pressed by equal force.

2. More space is provided to position sensors on the support. 3. More sensors can be placed to provide increased accuracy.

4. Smoother roller movement can be archived.

5. Less wear and tear occurs.

DESCRIPTION OF THE FIFTH EMBODIMENT Figure 13 shows a fifth embodiment of this invention. Two electrodes 42a and 42b are mounted on the- surface of the support 22. The electrodes 42a and 42b are laying next to each other. The electrodes have ground lines 40a and 40b placed opposite to the end of the electrodes. Electrodes 42 and counterpart ground line 40 have a minimal space separating them. The end of the roller 10 has conductive cam arrays 44a and 44b on the outer rim at the end of the roller. The end of the roller with cams 44 is laying in the middle, over the electrodes 42 and ground line 40. When the roller is rotated, the conductive cams 44 contact and connect electrodes 42 and ground line 40 in predetermined order.

The electrodes 42a 42b are connected to signal processing circuitry (not shown) which is between the sensor and data system. This interface electronic circuitry senses the outputs of the electrodes. Connection of an electrode to ground produces an electrical signal, which is stored as a data bit. The data bits give the system the required information about direction of rotation and quantitative information of magnitude and frequency. Interface electronics between the sensor and data system can be formed using semiconductor techniques on the same circuit board that the roller and sensors are located.

At the first stage, both electrodes are connected to ground simultaneously producing a data bit pair (0), (0). At the second stage, a first line is connected to ground resulting a data bit

(0) while comparative data bit on a second line is (1). At the third stage, the second line is connected to ground giving data bit (0), while the first line is (1).

Rotation of a two cam array roller results following data output: first electrode output 1 0 1 second electrode output 1 1 0

Rotation in a second direction reverses the order of the output.

DESCRIPTION OF THE SIXTH EMBODIMENT Figure 14a and 14b shows a Hall effect device employed to measure movement of a cantilever beam.

The basic structure of this device is like that of the first and second embodiments. Hall effect device 46 having connectors 26 is mounted on a support 22. A magnet 48 is located in the end of the cantilever beam 16. The roller 10 with polygonal shaped end 12 that moves the cantilever beam is mounted over the beam.

In the idle mode, the side 14 of the polygonal end 12 roller 10 is resting on cantilever beam 16. The beam is in the non-tensioned condition. Rotation of the roller 10 moves the edge

18 of the polygonal end down. The beam 16 bends and the magnet 48 in the end of the beam approaches the Hall device 46. A unipolar head-on magnet is used to cause a perpendicular magnetic flux for greatest sensitivity.

Upward and downward movements of the magnet 48 change the magnetic field. The changing magnetic field causes the Hall Effect voltage to change. The Hall Effect voltage is amplified by an operational amplifier incorporated in the Hall device. The amplified voltage is made available on output pin 26 or it is compared to a fixed internal voltage.

The asymmetrical change in magnet field results in a change in voltage similar to the change in resistance shown in Figures 4a and 4b for the first embodiment. The voltage is measured and, at two predetermined levels, triggers data bits that are stored in a memory. The direction of the rotation is determined in the same manner as in first embodiment. The magnitude of the movement is determined from the magnitude of the signal. Frequency can be sensed from the time difference between data bit pairs.

Alternatively a binary (1,0) digital signal is made available on an output pin 26 If improved accuracy is needed, also two cantilever beams can be employed as described in second embodiment. Methods disclosed in second embodiments can be used also with Hall effect device. Instead of measuring change in resistance, change in voltage is measured.

DESCRIPTION OF THE SEVENTH EMBODIMENT Alternatively, the rotation of the roller can be detected by capacitance changes. In Fig.

15 capacitance read out is done by using a first metal plate 50 in the end of the cantilever beam and a second metal plate 52 on the base below the first plate. The sensed capacitance is made to be part of an electronic oscillator. Changes in capacitance result in oscillator frequency changes. The oscillator frequency is measured by the interface electronic circuit and translated into data bits. The same method as in the first embodiment can be used to determine the direction of the rotation. Instead of measuring the resistance changes, the capacitance changes are measured.

Two opposite cantilever beams (not shown) can also be used as in second embodiment. The direction of rotation is determined by using the method described in the second embodiment. Instead of resistance changes, capacitance changes are measured. Capacitance sensors have higher stability, sensitivity and resolution than piezoresistive ones.

DESCRIPTION OF THE EIGHTH EMBODIMENT

In figure 16a the end of the roller 10 has a plurality of light reflecting elements 58 divided by light absorbing elements 60. A light emitting element, e.g. LED 54 or laser and a light detector 56 are formed to the silicon base 17 by semiconductor technique.

Figure 16b shows light 62 from LED 54 pointed upwards to the light reflecting elements 58. From the light reflecting elements 58 light is reflected down to a light detector, e.g. a phototransistor 56.

At least one light emitter and one light detector are needed to determine the direction of rotation. In figure 16b the end of the roller has a plurality of three different light reflecting elements in predetermined order. The light from LED 54 is reflected down with three different intensities and captured by the phototransistor 56.

The different light intensities are used to produce three different voltage signals measured by the interface electronic circuit and translated into data bits. The direction of a rotation is determined from the order of the signals.

An alternative way to determine the direction of rotation is shown in figures 17a, and b. Figure 17a shows a plurality of equal size reflecting elements 58 formed on the outer rim of the roller 10.

In figure 17b a photo diode 54 and two phototransistors 56 are formed to a silicon base by semiconductor technique. Light 62 is pointed up to the reflecting elements 58 of the roller 10 and reflected down to the phototransistors 56. Figure 17c shows phototransistors detecting radiation and producing two equal signals having a different phase. Electric signals are formed based on measurement. Data bit pairs are produced based on signals.

Figure 18 shows a configuration where two LED lights 54 are used to get maximum light intensity Figure 19a-e shows a polygonal end of a roller 10 having straight light reflecting elements 58 and the rotation of the roller. Resulted signals are comparable to those ones shown in figure 17c. By using a polygonal end with straight light reflecting elements, higher light intensity reflection is achieved. Also light absorbing elements between the reflectors 58 are not needed. If required even higher light intensities are archived by using a plurality of concave reflectors (not shown) on the outer rim of a roller.

In figure 19b longer lasting improved light intensity is achieved by using a plurality of one dimensionally concave reflectors which point the light down to a longitudinal area on predetermined line where the light detectors locate. In figure 19c a two dimensionally concave reflector collects the light and reflects it to a detector as a spot. A short, pointed, flash-type phenomena is resulted.

Manufacturing a light emitting diode and phototransistors as well as interface electronics on the same silicon base by using semiconductor technique makes mass production of the device economical. Since separate assembling of electronic components is not needed, manufacturing time is saved. Greater accuracy of placement of the light emitting and detecting elements is achieved.

CONCLUSION, RAMIFICATIONS AND SCOPE

The encoder disclosed in this invention can also be used to encode movement of a trackball. (Fig. 20) The dual-axis roller has two rollers 10 in perpendicular position. A third supporting roller 64 is added to support the roller from a third side. A track ball is placed to rest over these three rollers. The rollers are covered with non-friction rubber. The movement of the ball 70 is transformed to the rollers and encoded to a computer language.

Conventional mouse (Fig. 21a) movements can also be detected and encoded by using disclosed encoder. The roller device with two encoder rollers and a supporting roller 64 is placed on the ball 70 to detect the ball movement. Placing the encoder roller on the top of the ball instead of on the side gives several advantages: a) -more pressure against roller can be archived by pressing the mouse against the mouse pad. b) -more friction is achieved c) -mouse can be used as hand held track ball, which is not dependent on planar surface by taking the mouse in hand and turning it ball side up and moving the ball with a finger. d) -a dust protective ring brush 66 around the outer rim of the ball 70 can be added to clean the ball and protect the rollers 10 from getting dust from the working surface. Figure 21b shows the device mounted to a mouse housing.

This new invention not only makes conventional devices easier to use and cheaper to manufacture but also allows new application. Disabled people have used different types of cursor control devices, which typically lack accuracy. This roller device can be made so small that in can be placed behind the front teeth of a user (Fig. 22). Rollers can be rotated with the tongue accurately. Selections by switch actuation can be made by pressing the rollers by tongue or alternatively biting a designated switch (not shown). The small size of the rollers makes it possible to mount the roller and sensor device to a ring (Fig. 23) which can be put on e.g. a forefinger. On forefinger the rollers are easily rotatable by a thumb. Interface electronics can be located on the same silicon base as sensors and or in a special wristband (not shown). Radio transmitter or a cable can connect device to a host computer.

Finger mouse is convenient to use while typing. User doesn't need to move arms from writing position above the keyboard to move the cursor on a screen. Remote controlled instruments are conventionally controlled by a joystick type control device. Joysticks are mainly moved by wrist muscles that lack the sensitivity of a fingertip. Figure 24 shows a two-encoder device adapted to move a tool 86 to manipulate objects by telemanipulation in remote work site. Triple roller on the top of a handle 84 can be sensed by the most sensitive nerves of the human fingertip moved by the finger muscles that are used the make the finest movements.

The first roller lOx can be employed to move the instrument in x-axle direction, second lOy in y-axle direction wise and a third lOz z-axle.

Conventionally camera aperture and exposure time is adjusted from a ring around the objective (not shown). Instead of using conventional method, a touch roller can be involved (Fig. 25).

Preferably the roller should locate on top of the camera near shutter release button 82 where the rollers can be moved with a fingertip. First roller 80 is designated to select aperture and the second one 78 to change the shutter speed. Selected mode can be read from viewfinder indicator (not shown) and LCD panel (not shown) on the outer surface of a camera body. User can make change of the values quickly without changing grip.

Another application is to use a roller to drive a zoom lens(not shown). Conventional video cameras have a three-position switch to drive a zoom: Tele, wide and stand-by. Zoom is driven on standard speed.

A roller can be located on the outer surface of a camera body to drive the zoom. Preferred embodiment zoom length is related to rotation of a roller and the speed of zooming is related to the speed of rotation. Zooming speed adjustment adds a new dimension to video filming.

In figures shown here the end of the roller and the agitating means are rough for illustrative purposes. Preferably polygonal end with 20-40 sides should be used to agitate sensors. In general, the preferred embodiment produces at least 30 cursor-moving signals per rotation.

There are many additional applications where rotational encoders can be used. For example rollers can be connected to a robot arm to encode the distance the arm has traveled.

The disclosed invention is not limited only to be used as encoder. The same embodiments and methods can be used also as a transducer and rotation and velocity sensor.

While the invention has been described with respect to specific embodiments by way of illustration, many modifications and changes will occur to those skilled in the art. It is therefore, to be understood that the append claims are intended to cover all such modifications and changes as fall within the true scope and spirit of the invention.

LIST OF REFERENCE NUMERALS

10 roller 44 conductive cam

12 polygonal end of roller 46 Hall effect device

14 side of the polygon 48 magnet

16 cantilever beam 50 first metal plate

17 silicon base 52 second metal plate

18 edge of the polygon 54 LED light

20 piezoresistor 56 photo transistor

21 fulcrum of the cantilever beam 58 light reflecting element

22 support 60 light absorbing element

23 end of cantilever beam 62 light beam

24 cover of the device 64 supporting roller 26 connector 66 ring shape brush

28 turning point of the cantilever beam 68 mouse housing 30 contact/release point of an edge 70 ball 32 pressure sensitive resistor 72 tooth 34 shaft support 74 ring 36 polygonal cam 76 camera body 38 roller shaft 78 shutter speed adjustment 40 ground 80 aperture adjustment 42 electrode 82 shutter release button

84 handle

Claims

We claim:

1 A low profile encoder arrangement providing electric signals representing rotational motion in two directions comprising: a) a planar base; b) a rotatable motion energy receiver horizontally mounted on a upper surface of said planar base; c) a predetermined quantity of cams mounted on the outer rim of said motion energy receiver; d) a predetermined quantity of sensing means mounted on said upper surface of said planar base to receive agitation of said cams;

2 An encoder of claim 1 wherein -said planar base is micromachined out of crystal silicon plate.

-said cams is a polygonal end of said motion energy receiver.

-said sensing means comprises a cantilever beam formed by semiconductor techniques into said crystal silicon plate under said polygonal end of said receiver; and

-a piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said cantilever beam.

3 A method of determining the direction of rotation of said receiver of claim 2 by -applying motion energy to said motion energy receiver;

-applying a force against said cantilever beam by a corner of said polygonal end;

-bending said cantilever beam by said force; -changing a resistance of said piezoresistor in skewed, asymmetrical manner;

-measuring said resistance at a predetermined high level and a predetermined low level;

-resulting reverse electric signals on said high and low levels;

-having multiple groups of at least two closely timed, reverse electric signals separated by a longer period of time; -comparing the order of reverse electric signals in said separated group;

4 An encoder of claim 1 wherein

-said planar base is micromachined out of crystal silicon plate;

-said cams is a polygonal end of said motion energy receiver;

-said sensing means comprises a first and a second cantilever beam formed by semiconductor techniques into said crystal silicon plate under said polygonal end of said receiver; said first and second cantilever beams being in parallel position to each other and having their fulcrums in the opposite ends; and

-a first piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said first cantilever beam; and -a second piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said second cantilever beam.

5 A method of determining the direction of rotation of said receiver of claim 4 by -applying motion energy to said motion energy receiver;

-applying a force against said first and second cantilever beam by a corner of said polygonal end;

-bending said first and second cantilever beam from different positions by said force; -changing a resistance of said first and second piezoresistor in skewed, asymmetrical manner;

-measuring said resistance in said first resistor at a first high resistance level and second low resistance level;

-resulting in an electric signal at two predetermined resistance levels by said first resistor and resulting in a comparative electric signal by said second resistor; -measuring said resistance in said second resistor at first high level and second low level; -resulting in an electric signal at two predetermined resistance levels by said second resistor and resulting in a comparative electric signal by said first resistor; -comparing the order of reverse electric signal pairs. 6 A method of determining the direction of rotation of said receiver of claim 4 by

-applying motion energy to said motion energy receiver;

-measuring the rate of change from analog signals from said first and said second resistor;

-comparing the rate of change in said first and said second resistor. 7 An encoder of claim 1 wherein

-said cams is a polygonal end of said motion energy receiver.

-said sensing means comprises at least two pressure sensitive resistors mounted to the upper surface of said planar base, under said cams receiving agitation from said polygonal end in predetermined order, depending on the placement of the said resistors on said base. 8 A method of determining the direction υf rotation of said receiver of claim 7 by

-applying motion energy to said motion energy receiver;

-applying a force against said pressure sensitive resistors by a corner of said polygonal end;

-pressing said pressure sensitive resistors by said force; -changing a resistance of said resistors in predetermined order;

-measuring said resistance;

-resulting in a separable output electric signal group based on measurement; comparing the order of electric signal groups;

9 A method of determining the direction of rotation of said receiver of claim 7 by -applying motion energy to said motion energy receiver;

-pressing said pressure sensitive resistors by said force;

-changing a resistance of said resistors resulting at least two overlapping electric signals from said resistors;

-measuring said resistances;

-resulting at least two overlapping output electric signals based on measurement;

-producing at least three different signal combinations;

-comparing the order of electric signal combinations.

10 An encoder of claim 1 wherein

-said cams are mounted to the outer rim of said motion energy receiver in at least two arrays in predetermined order;

-said sensing means comprises pressure sensitive resistors mounted to the upper surface of said planar base, under a designated cam array, receiving agitation from said cams in predetermined order, depending on the placement of the said cams.

11 A method of determining the direction of rotation of said receiver of claim 10 by -applying motion energy to said motion energy receiver; -applying a force against said pressure sensitive resistors by said cams; -pressing said pressure sensitive resistors by said force; -changing a resistance of said resistors in predetermined order; -measuring said resistances;

-resulting at least three separable output electric signal pairs based on measurement; -comparing the order of electric signal pairs;

12 An encoder of claim 1 wherein

-said cams are made out of conductive material and placed in predetermined array. -said sensing means comprises at least two electrodes and a closely placed counterpart ground connectors;

13 A method of determining the direction of rotation of said receiver of claim 12 by -applying motion energy to said motion energy receiver;

-moving said cams into a simultaneous connection with at least one of said electrode and said counterpart ground connector at time in predetermined order;

-resulting a multiple of separable electric signal groups as a result of connections; -comparing the order electric signal groups.

14 An encoder of claim 1 wherein

-said planar base is micromachined out of crystal silicon plate. -said cams is a polygonal end of said motion energy receiver.

-said sensing means comprises a cantilever beam formed by semiconductor techniques into said crystal silicon plate under said polygonal end of said receiver; and -a magnet mounted to the end of said canalever beam

-a Hall device mounted under said magnet responding to changes in the magnetic field; 15 A method of determining the direction of rotation of said receiver of claim 14 by

-applying motion energy to said motion energy receiver; -applying a force against said cantilever beam by a corner of said polygonal end; -bending said cantilever beam by said force; -changing said magnetic field in skewed, asymmetrical manner; -measuring said voltage output from said Hall device at a predetermined high level and a predetermined low level;

-producing reverse electric signals on said high and low levels; -having a multiple of groups of at least two closely timed, reverse electric signals separated by a longer period of time; -comparing the order of reverse electric signals in said separated group;

16 An encoder of claim 1 wherein

-said sensing means is comprises a first metal plated placed in the end of said cantilever beam and a second metal plates mounted to said base under said first metal plate providing a capacitive read-out. 17 A method of determining the direction of rotation of said receiver of claim 16 by

-applying motion energy to said motion energy receiver; -changing the electric field between said plates in skewed, asymmetrical manner; -measuring said capacitive output from said first or second metal plate at a predetermined high level and a predetermined low level; -resulting reverse electric signals on said high and low levels;

-having a multiple of groups of at least two closely timed, reverse electric signals separated by a longer period of time; -comparing the order of reverse electric signals in said separated group; 18 A low profile encoder arrangement providing electric signals representing rotational motion in two directions comprising: a) a planar crystal silicon base; b) a rotatable motion energy receiver horizontally mounted on a upper surface of said planar base; c) a predetermined quantity of radiation reflecting elements mounted on the outer rim of said motion energy receiver; d) at least one radiation emitting element manufactured to said silicon base under said radiation reflecting elements by using semiconductor technique, illuminating radiation to said radiation reflecting element; e) at least one radiation detecting element, manufactured to said silicon base under said radiation reflecting elements by using semiconductor technique, receiving said illuminated radiation from said radiation reflecting elements. 19 An encoder of claim 18 wherein

-having a radiation emitting element; and -a radiation detecting element;

-said radiation reflecting element is a multiple groups of at least three different elements in predetermined order, separable by the intensity of reflection; 20 A method of determining the direction of rotation of said receiver of claim 19 by

-applying motion energy to said motion energy receiver;

-rotating said receiver with radiation reflecting elements over said radiation emitting element resulting at least three different radiation intensities reflected to said radiation detecting element; -resulting at least three different voltage level output based on received reflection;

-measuring the voltage levels;

-producing at least three different separable output signals based on measurement; -comparing the order of said output signals.

21 An encoder of claim 18 wherein -said radiation reflecting element comprises a plurality of equal radiation reflectors;

-having a radiation emitting element; and

-a first and a second radiation detecting elements placed close to each others to receive reflected radiation forming a equal length intensity wave having a different phase.

22 A method of determining the direction of rotation of said receiver of claim 21 by -applying motion energy to said motion energy receiver;

-rotating said receiver with radiation reflecting elements over said radiation emitting element;

-resulting an overlapping, equal length and intensity radiation reflection to said first and second radiation detecting elements; -said reflection captured by said radiation detecting elements in different overlapping phase depending on the placement of said detecting elements on said base;

-said radiation resulting a output voltage level change in detectors;

-measuring said voltage levels;

-producing three different separable output signal bit pairs based on measurement; -comparing the order of said output signals.

23 An encoder of claim 18 wherein

-said radiation emitting element is a light emitting diode. 24 An encoder of claim 18 wherein

-said radiation emitting element is a laser light.

25 An encoder of claim 18 wherein

-said radiation detecting element is a phototransistor. 26 An encoder of claim 18 wherein

-said radiation reflecting elements are formed on a outer convex surface of said motion energy receiver.

27 An encoder of claim 18 wherein

-said straight radiation reflecting elements are formed to a outer polygonal surface of said motion energy receiver.

30 An encoder of claim 18 wherein

-a curved radiation collecting and reflecting elements are formed to a outer surface of said motion energy receiver.

29 An encoder of claim 18 wherein -a concave radiation collecting and reflecting elements are formed to a outer polygonal surface of said motion energy receiver.

30 A low profile encoder arrangement providing electric signals representing rotational motion in x- and y-axis directions comprising: a) a planar base; b) a first and a second rotatable motion energy receiver horizontally mounted on a upper surface of said planar base preferably in transverse position, said receivers located so close to each others that both receivers can be rotated simultaneously by one finger touch to simultaneously change positional information in said x- and y-axis; c) a predetermined quantity of cams mounted on the outer rim of said first and second receiver; d) a predetermined quantity of sensing means mounted on said upper surface of said planar base to receive agitation of said cams of said first and second receiver;

31 An encoder of claim 30 wherein

-said planar base is micromachined out of crystal silicon plate. -said cams is a polygonal ends of said first and second motion energy receiver,

-said sensing means comprises a first and second cantilever beam formed by semiconductor techniques into said crystal silicon plate under said polygonal ends of said first and second motion energy receivers respectively; and

-a first and a second piezoresistor responding to dimensional changes, mounted on a upper surface of a fulcrum of said first and second cantilever beams respectively

32 An encoder of claim 30 wherein

-said planar base is micromachined out of crystal silicon plate; -said cams is a polygonal end of said motion energy receiver; -said sensing means comprises a first and a second cantilever beams formed by semiconductor techniques into said crystal silicon plate under said polygonal end of said first motion energy receiver; said first and second cantilever beams being in parallel position to each other and having their fύlcrums in the opposite ends; and

-a first piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said first cantilever beam; and

-a second piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said second cantilever beam. -a third and a fourth cantilever beams formed by semiconductor techniques into said crystal silicon plate under said polygonal end of said second motion energy receiver; said third and fourth cantilever beams being in parallel position to each other and having their fulcrums in the opposite ends; and -a third piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said third cantilever beam; and

-a second piezoresistor responding to dimensional changes mounted on a upper surface of a fulcrum of said fourth cantilever beam

33 An encoder of claim 30 wherein -said cams is a polygonal end of said first and second motion energy receiver.

-said sensing means comprises at least two pressure sensitive resistors mounted to the upper surface of said planar base, under said polygonal end of both of said first and said second motion energy receivers, receiving agitation from said polygonal end of said first and second motion energy receiver in predetermined order, depending on the placement of the said resistors on said base.

34 An encoder of claim 30 wherein

-said cams are mounted to the outer rim of said first and second motion energy receiver in at least two arrays in predetermined order;

-said sensing means comprises pressure sensitive resistors mounted to the upper surface of said planar base, under a designated cam array of said first and second motion energy receiver, receiving agitation from said cams in predetermined order, depending on the placement of the said cams.

35 An encoder of claim 30 wherein

-said cams are made out of conductive material and placed in predetermined array. -said sensing means comprises at least two electrodes and a closely placed counterpart ground connectors under both of said first and second motion energy receiver;

36 An encoder of claim 30 wherein

-said planar base is micromachined out of crystal silicon plate; -said cams is a polygonal end of said first and second motion energy receiver; -said sensing means comprises a first and a second cantilever beams formed by semiconductor techniques into said crystal silicon plate under said polygonal end of said first and second motion energy receiver respectively; and

-a first and a second magnet mounted to the end of said first and second cantilever beam respectively; -a first and a second Hall device mounted under said first and second magnet respectively responding to changes in a first and second magnetic field;

37 An encoder of claim 30 wherein

-said sensing means is comprises a first metal plate placed in the end of said first cantilever beam and a second metal plate mounted to said base under said first metal plate providing a capacitive read-out; and

-a third metal plate placed in the end of said second cantilever beam and a fourth metal plate mounted to said base under said first metal plate providing a capacitive read-out.

38 A low profile encoder arrangement providing electric signals representing rotational motion in x- and y-axis directions comprising: a) a planar crystal silicon base; b) a first and a second rotatable motion energy receiver horizontally mounted on a upper surface of said planar base preferably in transverse position, said receivers located so close to each others that both receivers can be rotated simultaneously by one finger touch to simultaneously change positional information in said x- and y-axis; c) a predetermined quantity of radiation reflecting elements mounted on the outer rim of said first and second motion energy receiver; d) at least one radiation emitting element manufactured to said silicon base under said radiation reflecting elements of said first and second motion energy receivers by using semiconductor technique, illuminating radiation to said first and second radiation reflecting element; e) at least one radiation detecting element for each of said first and second motion energy receivers, manufactured to said silicon base under said radiation reflecting elements of said first and second motion energy receivers, receiving said illuminated radiation from said radiation reflecting elements of said first and second motion energy receivers.

39 An encoder of claim 30 further comprising

-a third supporting roller mounted to said base forming a triangle with said first and second motion energy receivers

-a rotatable ball mounted to be in connection with said motion energy receivers and said third roller to receive motion energy and transforming the energy to said motion energy receivers.

40 An encoder of claim 38 further comprising -a third supporting roller mounted to said base forming a triangle with said first and second motion energy receivers

-a rotatable ball mounted to be in connection with said motion energy receivers and said third roller to receive motion energy and transforming the energy to motion energy receivers.

41 An encoder of claim 30 mounted to a steering wheel of a car to provide access to a computer

42 An encoder of claim 38 mounted to a steering wheel of a car to provide access to a computer

43 An encoder of claim 30 to be made small enough to be placed in users mouth against the teeth and said motion energy receivers being able to be rotated by the tongue of the user. 44 An encoder of claim 38 to be made small enough to be placed in users mouth against the teeth and said motion energy receivers being able to be rotated by the tongue of the user.

45 An encoder of claim 30 further comprising

-a ring which can be used to hold the device over the finger of the user, -a pressure sensitive selection button adjacent to motion energy receivers to make selections.

46 An encoder of claim 38 further comprising

-a ring which can be used to hold the device over the finger of the user, -a pressure sensitive selection button adjacent to motion energy receivers to make selections. 47 An encoder of claim 1 to be used to adjusts a aperture of a camera.

48 An encoder of claim 1 to be used to adjusts a shutter speed of a camera.

49 An encoder of claim 1 to be used to drive a zoom lens of a camera.

50 An encoder of claim 30 further comprising a third encoder roller to provide representative data in z-axis direction and adapted to move a tool by telemanipulation in remote work site.

50 An encoder of claim 38 further comprising a third encoder roller to provide representative data in z-axis direction and adapted to move a tool by telemanipulation in remote