RU2486575C1 - Device to create sensor surface - Google Patents

Abstract

FIELD: information technologies.

SUBSTANCE: device to create a sensor surface comprises the first and second radiators, an array comprising N optical receivers, a computing device and N receiving light guides, the first end of which is optically connected with one of optical receivers, and the second end is arranged along the line located in one plane with optical centres of the first and second radiators and is optically coupled with them, at the same time the sensor surface of the device represents a plane formed by crossing of radiation beams from the first and second radiator with the second ends of N optical fibres, and the computing device performs alternate connection of one of two radiators, input of signals from each of N photodetectors serially with the first and second connected radiator and calculates coordinates of the crossing point with a finger of a sensor surface operator.

EFFECT: simplified device and higher reliability of a device.

5 cl, 6 dwg

Description

The present invention relates to techniques for optoelectronic measuring systems and devices for inputting information into computer systems and control systems. Using this device, the touch surface can be organized in those places where the use of known systems is difficult or even impossible.

A number of devices for this purpose are known. For example, US Pat. No. 7,006,236 B2 of February 28, 2006, proposes a device that creates a virtual touch surface, touching it in certain places is equivalent to pressing buttons. This device contains a television camera, an optically coupled source of structured lighting and a computing device. The introduction of a finger into the radiation flux generated by the structured lighting source is recorded by a television camera. The computing device processes the video information coming from the television camera and determines the coordinates of the point of touch of the finger with the stream of structured radiation.

A device is also known (WO 2006/025891 A2), which proposes, among other things, the use in a car of a touch panel fixed to the steering wheel and allowing recognition of certain gestures of the driver, for which he should naturally touch his fingers with this panel.

The closest in technical solution is the patent of the Russian Federation No. 2278423 dated 10/15/2004 on "Device for interactive localization of objects" (prototype). This device uses two backlight sources (emitters) and an optically coupled photodetector, which is a line of photosensitive elements, the photodetector covering part of the perimeter of the surface being monitored. The intersection of the optical flows of the emitters with the sensitive surface of the photodetector and forms the surface of the “virtual keyboard”.

In addition, the device includes a computing device that controls the emitters, input information from the line of photodetectors and determine the coordinates of the point of intersection of the finger with the radiation flux generated by the emitters.

The algorithm of the computing device is based on the determination of the centers of shadows on the surface of a linear photodetector created when the emitters are turned on alternately, and then determining the coordinates of the intersection point of 2 lines connecting the center of the shadows with the optical center of the corresponding emitter.

The disadvantage of these systems is the need to place photodetectors (television cameras, phototransistors or photodiodes) in the immediate vicinity of the sensor field. In the case of using a television camera, there is a possibility of a malfunction of the system due to spurious flare and glare. Using Touchpad-a, mounted on the steering wheel of a car, worsens its ergonomics and makes driving difficult.

The aim of the invention is to simplify the device and increase reliability.

To do this, in the known device containing the first and second emitters, an array containing N optical receivers and a computing device, the inputs of which are connected to the outputs of each of the N optical receivers, and the outputs are connected to the first and second emitters, N receiving optical fibers, the first end each of which is optically coupled to one of the optical receivers, and the second end is located along a line located in the same plane with the optical centers of the first and second emitters and is optically coupled them, while the sensor surface of the device is a plane formed by the intersection of radiation beams from the first and second emitter with the second ends of N optical fibers, and the computing device turns on one of the two emitters in turn, and the signals from each of N photodetectors are input sequentially at the first and at the second emitter is turned on and calculates the coordinates of the point of intersection with the finger of the operator of the touch surface.

This technical solution allows you to organize a touch surface in previously inaccessible places, for example, in the area of the upper sector of the steering wheel of a car.

Figure 1 shows the functional diagram of the proposed device,

Where:

1, 2 - emitters,

3 ¹ ... 3 ^N - optical fibers,

4 ¹ ... 4 ^N - photodetectors,

5 - computing device

6 - touch surface.

The device operates as follows.

The computing device 5 alternately turns on one of the 2 emitters 1 and 2. They can be used as infrared LEDs.

, $${\Psi }_2^S$$

соответственно, образует при их пересечении некий объем, т.е. геометрически:These emitters form flows Ψ ₁ , Ψ _2, respectively, while part of the flows formed by emitters 1 and 2, which covers the second ends of the receiving optical fibers 3 ¹ ... 3 ^N and denoted $${\Psi }_{\mathrm{one}}^S$$

, $${\Psi }_2^S$$

accordingly, it forms a certain volume at their intersection, i.e. geometrically:

, $$\mathrm{FROM}P={\psi }_{\mathrm{one}}^S{\displaystyle \cap {\psi }_2^S}$$

,

Where:

SP - the amount of space occupied by the touch field in which the location of the finger of the operator is recorded.

The maximum extent of this volume in the direction in which it should be crossed by the finger of the operator is equal to the diameter of the end of the fiber, and can be fractions of a millimeter. The plane limiting this volume and facing the operator forms a touch surface 6.

The foregoing is illustrated in figure 2, where:

1, 2 - emitters,

Ψ ₁ , Ψ ₂ - light flux generated by emitters 1 and 2,

, $${\Psi }_2^S$$

- световые потоки, пересечение которых формирует сенсорную поверхность 6, $${\Psi }_{\mathrm{one}}^S$$

, $${\Psi }_2^S$$

- light fluxes, the intersection of which forms the sensor surface 6,

6 - touch surface

3 ¹ ... 3 ^N - receiving fibers,

Ω - input aperture of the receiving fibers,

D is the diameter of the optical fibers,

P is the finger of the operator,

P ¹ - the area of shading of the 1st emitter,

P ² - the area of shading of the 2nd emitter.

$${\Psi }_2^S$$

каких либо препятствий, попавшие в входную апертуру Ω приемных световодов 3¹…3^N излучения, последовательно, при поочередном включении излучателей 1 и 2, передаются к фотоприемпикам 4¹…4^N. При пересечении пальцем сенсорной поверхности 6 происходит перекрытие части излучений $${\Psi }_1^S$$

$${\Psi }_2^S$$

, при этом происходит затенение определенных торцов приемных световодов и, следовательно, изменение величин сигналов, вырабатываемых соответствующими фотоприемниками.If there are no threads in the path, $${\Psi }_{\mathrm{one}}^S$$

$${\Psi }_2^S$$

any obstacles that hit the input aperture Ω of the receiving optical fibers 3 ¹ ... 3 ^{N of} radiation, sequentially, when the emitters 1 and 2 are switched on one by one, are transmitted to the photodetectors 4 ¹ ... 4 ^N. When a finger crosses the touch surface 6, part of the radiation overlaps $${\Psi }_{\mathrm{one}}^S$$

$${\Psi }_2^S$$

when this occurs, the shading of certain ends of the receiving fibers and, consequently, a change in the magnitude of the signals generated by the respective photodetectors.

Figure 2 shows the situation when, when you turn on the emitter 1 and the intersection of the finger P of the touch surface 6, there is a shadowing of the zone P ¹ , and when you turn on the emitter 2, the shadowing of the zone P ² . In this case, a decrease in the magnitude of the signals of the photodetectors located in the corresponding zones.

Computing device 5 determines the groups of photodetectors to which radiation ceases to fall and calculates for each of them the number of the central element of the shaded area (for example, i when the 1st emitter is on and j when the 2nd is on).

Next, the coordinates of the object are determined as follows.

, $$(X_2^R,Y_2^R)$$

соответственно, уравнения прямых, проходящих через точки (Xⁱ, Yⁱ), ( $$X_1^R$$

, $$Y_1^R$$

) и (X^j, Y^j), ( $$X_2^R$$

, $$Y_2^R$$

) в представим в виде системы 1:The computing device 5, according to the numbers i and j, selects from the constants stored in its memory the coordinates of the ends of the optical fibers corresponding to these numbers (relative to some coordinate system 0XY) - (X ⁱ , Y ⁱ ), (X ^j , Y ^j ). Assuming that the coordinates of point radiation sources 1, 2 in the system $$0XY-(X_{\mathrm{one}}^R,Y_{\mathrm{one}}^R)$$

, $$(X_2^R,Y_2^R)$$

accordingly, the equations of lines passing through the points (X ⁱ , Y ⁱ ), ( $$X_{\mathrm{one}}^R$$

, $$Y_{\mathrm{one}}^R$$

) and (X ^j , Y ^j ), ( $$X_2^R$$

, $$Y_2^R$$

) in represent in the form of system 1:

;one) $$\frac{Y-Y^i}{Y_{\mathrm{one}}^R-Y_i}=\frac{X-X^i}{X_{\mathrm{one}}^R-X^j}$$

;

. $$\frac{Y-Y^i}{Y_2^R-Y^j}=\frac{X-X^j}{X_{\mathrm{one}}^R-X^j}$$

.

The coordinates of the center of the cross section of the finger that shaded the corresponding ends of the optical fibers are defined as the intersection point of these lines, i.e. as a solution to the system of equations 1, with respect to X, Y.

Figure 3 shows the second variant of the functional diagram of the device, where:

7, 8 - lighting fibers.

In this scheme, the radiation required for its creation of the sensor surface is formed using illuminating optical fibers 7 and 8, the first end of which is optically connected to the emitter, and the second is optically coupled to the second ends of the receiving optical fibers.

The functioning of the device in this case is carried out similarly to the scheme described above. Those. when the 1st and 2nd emitters are turned on sequentially, part of the optical fluxes coming from the optical fibers 7 and 8 and incident on the second ends of the receiving optical fibers 3 ¹ ... 3 ^N are detected by photodetectors 4 ¹ ... 4 ^N , the signals from which are fed to the input of the computational devices 5. Moreover, the algorithm of its operation in this case remains the same, namely, turning on the emitters 1 and 2 in turn, entering the signal values from the outputs of the photodetectors 4 ¹ ... 4 ^N and calculating the spatial coordinates of the operator’s finger according to formula 1, if it crosses the sensor the surface spine.

8 as an array of photodetectors in the proposed device can be used CCD or CMOS photodetector arrays. In this case, the ends of the receiving fibers must be in the same plane and be optically coupled to the photosensitive surface of the photodetector array, and it is required that each of the ends overlap at least one of its pixels.

Functional diagram of a device that implements this formula is shown in figure 4, where:

9 - photodetector matrix.

In this case, the computing device must input video information when the emitter 1 is on, and then when the emitter 2 is on, i.e. to enter the magnitude of the signals of each pixel forming a photosensitive surface of the matrix. When the operator’s finger passes through the touch surface, the video signal, in the corresponding pixels, decreases. Similarly, as in the case of the use of discrete photodetectors, the computing device determines the numbers of the unlit ends of the receiving optical fibers using the numbers of unlit pixels, and then, using formula 1, the coordinates X, Y of the finger of the operator are calculated.

Using a color or 2-spectral photodetector matrix, we can eliminate the need to turn on the emitters 1 and 2 in turn. For this, we use emitters operating in two spectral ranges, for example, in “blue” (B) and “red” (R), with maxima at regions of 470 nm and 610 nm, respectively, lying in the spectral ranges of subpixels constituting each pixel of a color photodetector (for example, Sony ICX413AQ type [4]).

The functional diagram of this embodiment of the device is shown in figure 5, where:

10 - two-spectral (color) matrix photodetector.

In this case, by analyzing the first color (for example, R) component of the video signal representing the states of the corresponding subpixels, it is possible to determine the coordinates of the unlit ends at the light flux of the first emitter (for example, “red”), and by analyzing the second color (for example B) component, it is possible to determine the coordinates of the unlit ends at the light flux of the second emitter (for example, "blue"). Further, according to the algorithm described above, the calculator 5 can determine the coordinates of the finger that crossed the touch surface 6.

If the total beam diameter of the receiving optical fibers 3 ¹ ... 3 ^N is of a size that does not allow optical connection with the photo-receiving matrix 9 or 10, a focusing lens should be placed between the plane in which the second ends of the receiving optical fibers and the photodetector are located imaging the common end of the bundle on the photodetector surface of the matrix. The foregoing is illustrated in Fig.6, where:

11 - harness connecting the receiving fibers,

12 - the common end of the tourniquet,

13 - focusing lens.

The computing device can be performed on the basis of a productive processor oriented to stream processing of video information, for example, of the type TMS320DM8148 based on DaVinci technology [5]. In addition, in the case of using a television camera with a standard USB interface, it can be connected directly to a personal computer, on which calculations of the coordinates of the operator’s finger will be implemented.

Literature.

1 - US Patent No. 7006236 B2 dated February 28, 2006.

2 - International patent No. WO 2006/025891 A2.

3 - RF Patent No. 2278423 dated 10/15/2004 (prototype).

4 - Diagonal 28.40 mm (Type 1.8) Frame Readout CCD Image Sensor with Square Pixel for Color Cameras. Sony reference material.

5 - http://www.ti.com/lsds/ti/dsp/platform/davinci/device.page.

Claims (5)

1. A device for creating a touch surface containing the first and second emitters, an array containing N optical receivers and a computing device, the inputs of which are connected to the outputs of each of the N optical receivers, and the outputs of which are connected to the first and second emitters, characterized in that contains N receiving optical fibers, the first end of each of which is optically coupled to one of the optical receivers, and the second end is located along a line located in the same plane with the optical centers of the first of the first and second emitters, and is optically paired with them, while the sensor surface of the device is a plane formed by the intersection of the radiation beams from the first and second emitters with the second ends of the N optical fibers, and the computing device alternately turns on one of the two emitters, input signals from each of the N photodetectors in series with the first and second emitter on and calculates the coordinates of the point of intersection with the finger of the operator of the touch surface. 2. The device according to claim 1, characterized in that it further comprises two lighting fibers, the first end of each of them being optically coupled to one of the emitters, and the second end being optically coupled to the second ends of the N receiving fibers, the sensor surface being formed by the intersection of the beams radiation emanating from the second ends of the light guides, with the second ends of the N receiving fibers. 3. The device according to claim 2, characterized in that each of the N optical receivers is at least one photosensitive pixel of a single matrix photodetector, and the second ends of all receiving optical fibers are located in the same plane optically connected with this matrix photodetector, In this case, its output is connected to the input of the computing device, and the computing device enters the pixel state of the matrix photodetector with one and then with the other emitter turned on and calculates the coordinates Ata finger crossing point of the touch surface of the operator. 4. The device according to claim 3, characterized in that each pixel of the matrix photodetector consists of at least two color subpixels with different spectral sensitivities corresponding to the spectra of the first and second emitters, and these emitters are turned on constantly, and the computing device enters color states subpixels of the matrix photodetector and calculates the coordinates of the point of intersection with the finger of the operator of the touch surface. 5. The device according to claim 4, characterized in that between the ends of the receiving fibers and the photodetector is located optically paired with a focusing lens.

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