Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
  • G01S7/481—Constructional features, e.g. arrangements of optical elements
  • G01S7/4818—Constructional features, e.g. arrangements of optical elements using optical fibres
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
  • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
  • G01S17/04—Systems determining the presence of a target
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
  • H03K17/941—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated using an optical detector
  • H03K17/943—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated using an optical detector using a plurality of optical emitters or detectors, e.g. keyboard

Definitions

• the invention relates to a device and a method for optoelectronic detection of the movement and / or position of an object according to the preamble of claims 1 and 18.
• keyboards on the market so far mostly consist of individual mechanical switching elements. An electrical contact is closed or opened by pressing the operating finger. Such keyboards contain moving parts that are subject to mechanical wear. As individual switching elements, as can be seen, for example, from US Pat. No. 4,092,640 A1, buttons are also used that take advantage of the antenna effect of the human body.
• the present invention has for its object to provide the conditions for the construction of a button that can be operated under a closed surface.
• a light guide is used, which is at least able to couple light into the light guide, which was previously shone through the light guide and diffusely backscattered from any object at any angle change.
• 1 is a side view of a light guide with light coupling means when approaching an object with details of the light beam path
• FIG. 3 shows the side view of an optical fiber in which the optoelectronic components are arranged on the edge of the optical fiber
• FIG. 4 shows a block diagram
• FIG. 5 shows the signal curve when an object approaches
• Fig. 8 is a rotary keypad.
• the figures show a device for optoelectronic detection of the movement and / or the position of an object 10.
• the device has at least one transmitting element 11 for emitting radiation in the wavelength range of light from infrared to ultraviolet and at least one receiving element 12 for receiving at least part of the radiation emitted by the transmitting element 11 and scattered on the object 10.
• a light guide is arranged in the beam path between transmitting element 11 and receiving element 12.
• This light guide 13 itself has light coupling means for coupling in the radiation diffusely scattered on the object 10 and previously radiated through the light guide 13 and subjected to an angular change on the object.
• the radiation is coupled in by the light coupling means 13a according to FIG.
• the light coupling means is shaped in the light guide in such a way that incident rays transversely to the light guide are totally reflected from a certain angle and are then passed on in the light guide. Light arriving at right angles to the light guide is thus diverted at almost a right angle, depending on the optical properties of the light guide.
• the light coupling means can also be used to decouple the incident light. As in FIG. 1, the transmitting element 11 can shine through the light guide, so that the radiation does not initially enter the light guide since it is not subject to the total reflection required for this. However, if the light is then backscattered by the object 10, the backscattered light is totally reflected in the light guide at the light coupling means 13a and then “caught” in the light guide.
• the reflective properties of the light guide 13 and the arrangement of the transmission element with respect to the light guide are such that the transmission element 11 can essentially transmit the light through the light guide, but if the light is diffusely backscattered by the object 10 even with only a slight change in angle, total reflection of the “captured” light beam is possible in the exemplary embodiment, so that the light is then passed on in the light guide can be.
• the transmitter element is usually located on the side 13b of the light guide, which faces away from the moving and / or approximating object 10.
• the light guide itself can also form the closed surface under which the keyboard to be operated is protected. By choosing this surface there are no cracks and the material allows it to be used in areas with strong environmental influences, mechanical or chemical.
• the light guide 13 can also have a plurality of light coupling means 13a.
• the light coupling means 13a are preferably spatially assigned to a transmitting element 11, so that the transmitting elements 11 can be arranged in the form of a keyboard.
• the assigned light coupling means 13a which can preferably be designed in the form of an arc or a segment of a circle, is then located on each key 14 - indicated by dashed lines in FIG. 2.
• a transmission element 11 in the form of a light-emitting diode is preferably used for each key. All transmitting elements 11 act on the receiving element 12 by means of suitable optics, which is also illuminated by an additional compensation LED 15.
• the light coupling means 13a can be produced, for example, by milling into the light guide 13.
• transmission elements and reception elements can also be reversed.
• the keys can be assigned a plurality of receiving elements, for example a receiving element for each key, while at least two transmitting elements are preferably arranged at a suitable location. When arranging the transmission elements, it is only necessary to ensure that a light path up to the reception elements is possible.
• two measuring sections are set up between the sending element and the receiving element. While the transmitting element emits the radiation, the receiving element determines the reflection reflected on surfaces or objects. As also shown in FIG. 4, the two measuring sections are operated in sections by a clock generator 20.
• the clock signals are routed via a multiplexer 23, in order to control further transmission elements 11, particularly in the case of a keyboard.
• the detection signals ascertained by the receiving element 12 are filtered and in a synchronous demodulator 21 controlled by the clock generator 20 are broken down again into signals that can be assigned to the individual measuring sections.
• the useful signal determined by comparing the measuring sections is fed to an evaluation unit 24, which switches a device 25 as a function thereof.
• a useful signal of zero results.
• the useful signal is fed to a signal centering stage.
• the radiation quantity radiated into the measurement sections is then controlled with this control voltage, so that the detection signal is readjusted as a function of a time constant.
• this takes place via the compensation LED 15, which is operated with the counter-phase clock signal and is regulated on the basis of the useful signal at the controller 28.
• the compensation LED 15 can also be operated directly next to a receiving element 12, since a light path of almost zero is also sufficient for compensation.
• the transmitting elements 11 should be assigned to the “buttons” 14; the receiving element 12 and the compensation LED 15 can also be spaced apart from this in this embodiment.
• One of the transmitting elements 11 itself can also be used as the compensation LED 15.
• the compensation LED is thus preferably arranged on the edge of the light guide 13. 3, the compensation LED 15 can be arranged, for example, on an inclined edge 13c of the light guide. According to FIG. 3, this results in the possibility of not providing the printed circuit board 16 over the entire area below the light guide.
• the circuit board with the optoelectronic components 17 can thus also be provided only in the region of the inclined or beveled edge 13c of the light guide, while the light guide 13 itself projects outwards as a free keyboard. But not only the receiving element 12 and the compensation element 15 can be arranged at the edge; in an embodiment according to FIG. 3, the transmitting elements 11 themselves can also be arranged at a distance from the actual input area, which is located in the area of the light coupling elements 13a.
• the light guide can be constructed, for example, in a planar manner and thus arranged on a keyboard without interference from optoelectronic or other components, since the light guide is separated from them.
• This enables all optoelectronic components to be mounted on a circuit board and the light guide to be planar.
• the light guide is formed such that it is e.g. Milled as light coupling means.
• the corresponding light coupling means in the light guide, e.g. by pouring. If the interfaces are carefully designed, it can be used to produce light guides that may not be statically weakened by milling.
• the transmission elements are fed sequentially with a clock.
• the compensation LED 15 receives the inverse clock in a controlled manner.
• the intensity is regulated according to the compensation LED 15 so that the transmitter element 11 and the compensation LED 15 on the receiver 12 result in the same signal amplitude. This is done cyclically for all transmission elements 11, each for a few clock cycles.
• the synchronous demodulator and controller 21 delivers a signal sequentially for each of the possible control loops. When an object 10 approaches, this control signal has, for example, the course shown in FIG. 5.
• a corresponding optical button that works in this way is known from WO 01/54276 A1.
• the change brought about by the movement of the finger is evaluated according to the method known from WO 01/54277 A1.
• the compensation LED light e.g. Radiate the same strength in an unregulated manner, while the transmission elements are individually adjusted. As a result, nothing changes.
• the signal shown in FIG. 5 is obtained in the form of samples which are sampled at intervals of a few milliseconds.
• a sampling frequency of, for example, 200 kHz the individual transmission elements 11 are driven sequentially and queried as soon as they have settled.
• the result is an image according to FIG. 6, from which, for example, a course according to FIG. 5 can be derived.
• 5 differs from waveforms which are generated by movement in the vicinity of the input field or by wiping due to the sudden change in the signal when the finger hits the key surface (position 30), a stable level for the dwell time of the Fingers, which is at least 80 milliseconds, and due to the drop in the signal when the finger is removed in accordance with position 31.
• Other signal changes are evaluated as an approximation and can be used to activate a key illumination or to activate the connected device. It is also conceivable to give visual or acoustic feedback when a key is detected.
• radiation in the wavelength range of the light is emitted, the light is transmitted through a light guide 13 to the object 10 and backscattered from the object.
• the backscattered amount of light is at least partially coupled into a light guide 13 and received by the receiving element 12 to form an input signal.
• the movement and / or position of the object 10 is determined from this in an evaluation unit.
• the coupling takes place via light coupling means 13a of the light guide 13 itself, preferably transversely to the light guide.
• the individual keys In addition to the use as a classic keyboard, it is also possible, for example, to arrange the individual keys smaller than dots in a matrix. If this matrix has at least 5 x 7 points, all alphanumeric characters can be entered.
• a standard display element can be used here as the send array. It makes sense to permanently illuminate the recognized keys in order to provide the user with feedback and thus to simulate a typing process.
• the activation of the LEDs used as transmission elements takes place sequentially.
• the illumination can therefore take place during the pauses in the query, especially since the transmission frequency is preferably not perceptible to the human eye. This enables the signals determined to be used as input for character recognition.
• the constant light generated by permanent lighting does not interfere with the key evaluation, since it only works with modulated light.
• FIG. 7 A side view of such a slider could have a shape according to FIG. 3, provided the light coupling means 13a is guided across a longer area transversely to the plane of the image.
• FIG. 8 With a circular arrangement according to FIG. 8 of, for example, 12 keys, a keyboard similar to a dial keyboard 27 can also be created.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Computer Networks & Wireless Communication (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Push-Button Switches (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=27797769

Family Applications (1)

Country Status (6)

Families Citing this family (61)

Citations (1)

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• 2002
  • 2002-03-13 DE DE10211307A patent/DE10211307A1/de not_active Ceased
• 2003
  • 2003-03-11 EP EP03711964A patent/EP1485674A1/de not_active Withdrawn
  • 2003-03-11 US US10/507,453 patent/US7280714B2/en not_active Expired - Lifetime
  • 2003-03-11 JP JP2003575049A patent/JP4307267B2/ja not_active Expired - Lifetime
  • 2003-03-11 WO PCT/EP2003/002452 patent/WO2003076870A1/de active Application Filing
  • 2003-03-11 AU AU2003218723A patent/AU2003218723A1/en not_active Abandoned

Patent Citations (1)

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