阅读说明：本技术 一种判断红外触摸屏真实触摸或悬浮的方法 (method for judging real touch or suspension of infrared touch screen ) 是由 宫姜男 于 2018-05-28 设计创作，主要内容包括：本发明公开了一种判断红外触摸屏真实触摸或悬浮的方法,包括步骤：A1、红外摄像头接收识别红外光源像和触摸屏反射光像；A2、一旦没有接收到红外光源像,则判定有触摸物体触摸到触摸屏。本发明一改现有技术仅以红外光接收受阻作为判定触摸物体已触摸到触摸屏的判定方法,根据红外摄像头接收的红外光源像和触摸屏反射光像计算触摸物体离触摸屏的距离,然后细化判断触摸物体是否真实触摸到触摸屏,降低了误判可能性,提高了红外触摸屏的灵敏度,增强了用户友好性。(the invention discloses a method for judging real touch or suspension of an infrared touch screen, which comprises the following steps: a1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera; and A2, judging that the touch object touches the touch screen when the infrared light source image is not received. The invention changes the prior art into a method for judging that the touch object touches the touch screen only by taking the infrared light receiving blockage as a judgment method, calculates the distance between the touch object and the touch screen according to the infrared light source image received by the infrared camera and the reflected light image of the touch screen, and then thinly judges whether the touch object actually touches the touch screen, thereby reducing the possibility of misjudgment, improving the sensitivity of the infrared touch screen and enhancing the user friendliness.)

1. A method for judging real touch or suspension of an infrared touch screen is characterized by comprising the following steps:

a1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

And A2, judging that the touch object touches the touch screen when the infrared light source image is not received.

2. A method for judging real touch or suspension of an infrared touch screen is characterized by comprising the following steps:

B1, the infrared camera receives and identifies the infrared light source image and the reflected light image of the touch screen;

and B2, judging that the touch object touches the touch screen when the infrared light source image is not received and only part of the reflected light image of the touch screen is received.

3. A method for judging real touch or suspension of an infrared touch screen is characterized by comprising the following steps:

c1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

And C2, judging that the touch object is suspended above the touch screen once the infrared light source image is not received and the complete reflected light image of the touch screen is received.

4. a method for judging real touch or suspension of an infrared touch screen is characterized by comprising the following steps:

D1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

D2, once only partial infrared light source images are received and the complete reflected light image of the touch screen is received, judging that a touch object is suspended above the touch screen.

5. a method for judging real touch or suspension of an infrared touch screen is characterized by comprising the following steps:

E1, receiving and identifying the infrared light source image and the reflected light image of the touch screen by the infrared camera;

e2, calculating the distance between the touch object and the touch screen according to the received infrared light source image and the reflected light image of the touch screen;

E3, setting a distance threshold, judging that the touch object touches the touch screen once the distance between the touch object and the touch screen is smaller than the distance threshold, and otherwise judging that the touch object floats above the touch screen.

6. The method for judging the real touch or suspension of the infrared touch screen as claimed in claim 5, which comprises the steps of: the method comprises the following steps that a plurality of infrared cameras receive and recognize infrared light source images and touch screen reflected light images, the distance between a touch object and a touch screen is calculated according to the infrared light source images and the touch screen reflected light images received by each infrared camera, and the average value of all the distances is obtained; and setting a distance threshold, judging that a touch object touches the touch screen once the average value is smaller than the distance threshold, and otherwise judging that the touch object floats above the touch screen.

Technical Field

The invention relates to the technical field of infrared touch screens, in particular to a method for judging real touch or suspension of an infrared touch screen.

Background

the infrared touch screen is composed of infrared transmitting and receiving elements arranged on the outer frame of the touch screen, an infrared detection network is formed on the surface of the screen, when a touch object blocks infrared light, the infrared receiving elements cannot receive the infrared light, and at the moment, the coordinate position of the touch object is calculated and operation response is realized. In the prior art, as long as infrared light reception is found to be blocked by scanning, it is determined that a touch object touches the touch screen, but sometimes the touch object (such as a mouse) does not touch the touch screen but floats above the touch screen, infrared light reception is still blocked, and at this time, if the touch object is judged to be touched, erroneous judgment may be caused.

Disclosure of Invention

the technical problem to be solved by the present invention is to provide a method for determining real touch or suspension of an infrared touch screen, aiming at the defects of the prior art, and overcoming the defect that the real touch and suspension states cannot be distinguished when determining touch of the touch screen.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a method for judging real touch or suspension of an infrared touch screen comprises the following steps:

A1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

and A2, judging that the touch object touches the touch screen when the infrared light source image is not received.

A method for judging real touch or suspension of an infrared touch screen comprises the following steps:

B1, the infrared camera receives and identifies the infrared light source image and the reflected light image of the touch screen;

and B2, judging that the touch object touches the touch screen when the infrared light source image is not received and only part of the reflected light image of the touch screen is received.

a method for judging real touch or suspension of an infrared touch screen comprises the following steps:

C1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

And C2, judging that the touch object is suspended above the touch screen once the infrared light source image is not received and the complete reflected light image of the touch screen is received.

a method for judging real touch or suspension of an infrared touch screen comprises the following steps:

D1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

d2, once only partial infrared light source images are received and the complete reflected light image of the touch screen is received, judging that a touch object is suspended above the touch screen.

A method for judging real touch or suspension of an infrared touch screen comprises the following steps:

E1, receiving and identifying the infrared light source image and the reflected light image of the touch screen by the infrared camera;

e2, calculating the distance between the touch object and the touch screen according to the received infrared light source image and the reflected light image of the touch screen;

e3, setting a distance threshold, judging that the touch object touches the touch screen once the distance between the touch object and the touch screen is smaller than the distance threshold, and otherwise judging that the touch object floats above the touch screen.

According to an embodiment of the invention, the method comprises the steps of: the method comprises the following steps that a plurality of infrared cameras receive and recognize infrared light source images and touch screen reflected light images, the distance between a touch object and a touch screen is calculated according to the infrared light source images and the touch screen reflected light images received by each infrared camera, and the average value of all the distances is obtained; and setting a distance threshold, judging that a touch object touches the touch screen once the average value is smaller than the distance threshold, and otherwise judging that the touch object floats above the touch screen.

The technical scheme of the invention has the following beneficial effects: the invention changes the prior art into a method for judging that the touch object touches the touch screen only by taking the infrared light receiving blockage as a judgment method, calculates the distance between the touch object and the touch screen according to the infrared light source image received by the infrared camera and the reflected light image of the touch screen, and then thinly judges whether the touch object actually touches the touch screen, thereby reducing the possibility of misjudgment, improving the sensitivity of the infrared touch screen and enhancing the user friendliness.

Drawings

the advantages and realisation of the invention will be more apparent from the following detailed description, given by way of example, with reference to the accompanying drawings, which are given for the purpose of illustration only, and which are not to be construed in any way as limiting the invention, and in which:

FIG. 1 is a schematic diagram of an infrared touch screen barrier imaging of the present invention;

FIG. 2 is a schematic diagram of the geometric relationship for calculating the distance of the obstruction from the infrared touch screen according to the present invention;

FIG. 3 is a schematic view of an arrangement of an infrared transmitting tube and a camera according to an embodiment of the present invention;

FIG. 4 is a schematic view of an infrared light source image and a touch screen reflected light image according to the present invention;

FIG. 5 is a process flow diagram of the present invention;

FIG. 6 is a schematic diagram of calculating the distance of an obstruction from an infrared touch screen according to the present invention.

Detailed Description

As shown in fig. 5, the method for determining the real touch or suspension of the infrared touch screen of the present invention includes the steps of:

a1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

And A2, judging that the touch object touches the touch screen when the infrared light source image is not received.

The invention also provides a method for judging real touch or suspension of the infrared touch screen, which comprises the following steps:

B1, the infrared camera receives and identifies the infrared light source image and the reflected light image of the touch screen;

And B2, judging that the touch object touches the touch screen when the infrared light source image is not received and only part of the reflected light image of the touch screen is received.

the invention also provides a method for judging real touch or suspension of the infrared touch screen, which comprises the following steps:

C1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

and C2, judging that the touch object is suspended above the touch screen once the infrared light source image is not received and the complete reflected light image of the touch screen is received.

A method for judging real touch or suspension of an infrared touch screen comprises the following steps:

d1, receiving and identifying an infrared light source image and a touch screen reflected light image by an infrared camera;

D2, once only partial infrared light source images are received and the complete reflected light image of the touch screen is received, judging that a touch object is suspended above the touch screen.

The invention also provides a method for judging real touch or suspension of the infrared touch screen, which comprises the following steps:

e1, receiving and identifying the infrared light source image and the reflected light image of the touch screen by the infrared camera;

e2, calculating the distance between the touch object and the touch screen according to the received infrared light source image and the reflected light image of the touch screen;

E3, setting a distance threshold, judging that the touch object touches the touch screen once the distance between the touch object and the touch screen is smaller than the distance threshold, and otherwise judging that the touch object floats above the touch screen.

the method comprises the following steps that a plurality of infrared cameras receive and recognize infrared light source images and reflected light images of the touch screen, the distance between a touch object and the touch screen is calculated according to the infrared light source images and the reflected light images of the touch screen received by each infrared camera, and the average value of all the distances is taken; and setting a distance threshold, judging that a touch object touches the touch screen once the average value is smaller than the distance threshold, and otherwise judging that the touch object floats above the touch screen.

As shown in fig. 1, the light source may be a point light source or a line light source; a touch screen is arranged below the light source; the light source emits light and is captured by the camera; the imaging light source is divided into two parts, one part is a direct light source of the infrared emission tube, and the other part is a reflection light source reflected by the touch screen; the infrared emission tube direct light source is at a certain distance from the reflecting surface of the touch screen, so that the camera can distinguish the image of the light source from the reflected image; when the shielding object is close to the reflecting surface of the touch screen, the distance between the shielding object and the camera or the distance between the shielding object and the light source can be estimated by calculating the brightness of the image of the light source and the brightness of the reflected image.

as shown in fig. 2, as the height of the shade is gradually reduced,

a. when the sheltering object is positioned at the right side of the boundary of the area, the image of the light source is sheltered firstly, and the reflected image is sheltered later;

b. when the shielding object is positioned at the left side of the boundary of the area, the image of the light source is firstly shielded, and the reflected image is simultaneously and partially shielded.

at this time:

1) The image of the light source and the reflected image are not shielded, and the shielding object is far away from the reflecting surface of the touch screen; 2) the image of the light source is completely or partially shielded, and when the reflected image is not completely shielded, the shielding object is closer to the reflecting surface of the touch screen;

3) The image of the light source is completely shielded, and then the shielding object is close to the reflecting surface of the touch screen.

in the process that the sheltering object gradually approaches the reflecting surface:

1. If the image of the light source is shielded firstly and the reflected image is shielded later, the fact that the shielding object is away from the camera to the right side of the boundary line of the area is indicated;

2. if the image of the light source and the reflected image are simultaneously blocked, the blocking object is on the left side of the boundary of the area;

3. when the image of the light source is completely blocked, the distance between the blocking object and the light source is judged by calculating the intensity (shape or brightness) of the reflected image, and when the blocking object is close to the boundary line, the reflected image intensity is strong, and when the blocking object is close to the light source, the reflected image intensity is weak.

Calculation method

the image processing obtains the intensity a of the image of the light source, the intensity b of the light source and the distance from the point E to the reflecting surface, AB/BC equals to AD/EC, AB + BC equals to AC, and the height of the obstruction can be calculated.

Assuming that the image of the light source is completely blocked, the ratio of the intensity of the reflected image to the maximum intensity of the reflected image is x%, and when the obstruction is to the left of the boundary line, the distance from the light source to the obstruction can be expressed as: AB multiplied by x%. At the same time the estimated height of the shade at that moment can be calculated.

As shown in fig. 3, the light sources are infrared light emitting diodes, which are distributed on four sides of a rectangle of a lower drawing, and cameras are also arranged on four sides of the rectangle to collect signals of a plurality of infrared light emitting diodes, the lower drawing is only a schematic diagram, the edges of a rectangular touch plane can be placed according to circumstances as appropriate, and are composed of cameras and infrared light emitting points distributed at equal intervals, and the light emitting points can be realized by using infrared emitting tubes or light splitting bars with light splitting capability, wherein the number of the rectangular cameras and the light emitting points can be selected according to the performance requirements, if the touch effect requirements are not high, 4 cameras can be arranged on four vertexes, the distances between the light emitting points are larger (9mm is taken as an example), and if the touch effect has certain requirements, cameras (6 or 8 in total) and the distances between the light emitting points are smaller (5-6 mm is taken as an example) can be installed at the upper and lower and left and right bottom. The following description will take the example of placing cameras at four corners and the center line of the upper and lower bottom edges. Cameras 1, 2, 3, 4 are placed at the touch zone vertices, camera 5 at the upper mid-point and camera 6 at the lower mid-point.

obtaining data

the cameras shoot at certain intervals (for example, 5 milliseconds), simultaneously or in a certain sequence to acquire frame luminous images.

the camera 1 is responsible for collecting data on the top and right sides of the touch area.

the camera 2 is responsible for collecting data at the bottom and right of the touch area.

The camera 3 is responsible for collecting the touch area bottom and left data.

the camera 4 is responsible for collecting the top and left side data of the touch area.

The camera 5 is responsible for collecting touch area bottom edge data.

The camera 6 is responsible for collecting touch area top edge data.

As shown in fig. 4, the brightness information of all the infrared light emitting tubes on the bottom side of the rectangle is collected, which includes two parts of direct projection and reflection, the upper half is a light source image, the lower half is an image of the light source reflected by the touch surface, each vertical line represents one light emitting tube, the linear light source is a line, and the point light source is a point.

luminance reference value: when there is no object near the touch surface, the luminance of each light-emitting point and the image reflected by the light-emitting point, the number i of the light-emitting point, the luminance is denoted as Bi, and the luminance of the image is denoted as Bi'.

Current value of brightness: when an object is present near the touch surface, the luminance of each light-emitting point and the image reflected by the light-emitting point, i, which is the number of the light-emitting point, is denoted as Li, and Li' is the luminance of the image.

shielding the wire: when Li/Bi or Li '/Bi' is below a certain ratio (0.8 as an example), it is considered that a shade exists. It can be presumed that the obstruction is on the connection line between the camera and the i-th light emitting point, which is called a blocking line, and several blocking lines can be obtained by performing the same process for each camera.

As shown in fig. 6, taking the presence of A, B two touch points as an example, the black straight line from the camera position to the corresponding side is a shading line.

1. and intersecting different shielding lines to acquire the possible positions (straight line intersection points) of the touch points.

2. And excluding the non-touch points according to the number of straight lines crossing the straight lines, the distance estimation of the distance camera and the historical track. The distance estimation method is the method for estimating the distance of the obstruction described above, and the historical track is a historical record of the coordinates of the touch point calculated in the screen. For example, if the number of straight lines passing through the intersection is small, the straight lines are excluded, if the intersection position and the estimation gap are too large, the straight lines are excluded, and if the intersection position and the estimation gap are not in accordance with the history track, the straight lines are excluded as appropriate.

3. the coordinates of the touch point A, B are calculated.

4. Taking point A as an example, six occlusion lines pass through point A, the height h1h2. h6 of point A on each occlusion line is estimated by the method for estimating the height of the occlusion object mentioned above, and h1 is calculated

the average value of h2 … h6, as the height h of the shade, is determined by the actual use of the device,

Selecting a value H, reporting the point A as a touch point when H < H is, and reporting the touch point when H > is H,

Point a reports suspension.

output of

and reporting the touch information to an operating system by using a USB HID protocol or a custom protocol through a USB or serial port or other connection modes, and displaying effects such as a point track, a suspension state and the like by matching software in the operating system.

as will be apparent to those skilled in the art, many modifications can be made to the invention without departing from the spirit and scope thereof, and it is intended that the present invention cover all modifications and equivalents of the embodiments of the invention covered by the appended claims.