JPS625428A - Optical positioning apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improved optical positioning device, and more particularly to a device for determining the position of an object within a target area by optical means.

Although the present invention is applicable to various fields, the disclosure herein is primarily limited to applications to optical touch screen input devices such as computers. With such contravention of computers and convenience stores and similar devices,
There has been an increasing recognition of the need to simplify the operator-computer interface, for example to facilitate the entry of data into the computer. Keyboards, joystick controls, and various types of "touch screen input devices" have been developed as such devices.

[Problem that the invention seeks to solve]

Touch screen input devices are commonly utilized with CRT-type displays found in many computers and computer terminals.

These touch screen input devices include a screen lamination element overlaid on a CRT display screen, and the input device may be of the capacitive or resistive type, alternatively utilizing ultrasound, or It consists of a conductive grid. Generally speaking, this laminated element detects or determines the position of a pointer, finger, etc. for selecting or indicating the portion of information to be displayed on the display screen. . However, the provision of such laminated elements in front of the CRT results in a reduction in the visual quality of the display for the operator. That is, such laminated elements not only reduce the contrast and brightness of the display to the operator, but also reduce the resolution of the display. In many applications, increased resolution of a display is an important functional feature, and the addition of such laminated elements that degrade resolution is undesirable.

Moreover, laminated elements attract dirt and dust, further contributing to the deterioration of display quality.

Laminated elements are often made of materials that are susceptible to scratches or otherwise become damaged over time or with increased use, compounding this problem of visual quality degradation of the display.

Additionally, these materials reduce the effectiveness of anti-glare finishes in the display area of the RT. In addition, touch screens with these laminated elements typically reduce the resolution of their own sensing and positioning capabilities. Attempts to increase this result in increased complexity and manufacturing costs.

Optical touch screen input devices have been proposed that overcome the shortcomings of touch screen laminated elements.

This optical device generally creates a "curtain of light" in front of the CRT, preferably in the non-visible infrared range, thereby providing an interference zone between the operator and the screen of the display. If this curtain is broken by an object such as an operator's finger or a pencil, this will be easily detected by the device and the location where the object broke will be displayed on the touch screen.
That is, it is fixed to the display screen.

In one such widely used optical touch screen input device, a generally rectangular target area is defined by a generally rectilinear frame. A light distribution and detection device is provided in one corner of the frame to direct light into the target area. A reflector assembly is positioned along one side of the target area.
Extending from one corner of the optical distribution and detection assembly. A third reflector assembly is provided along the other side of the target area, sandwiching the free end of one of the first two assemblies in one corner where the optical distribution and detection device is installed. The third reflector assembly and the opposing reflector assembly comprise retroreflector assemblies arranged to directly reflect light incident thereon along its path. Preferably, the remaining reflector assemblies include mirrors arranged to reflect light emitted from the light source onto one of the retroreflective assemblies and vice versa.

Detectors are provided to detect light returned from each retroreflective assembly and mirror. A scanning assembly is provided to scan a target area for receiving the returned beam of light.

Therefore, once the angular position of the scanning assembly relative to the target area at a given time is determined, the angular orientation of the path of the returning light incident on the detector at that moment is also determined. If there is an object within the target area,
There will be a significant reduction in the amount of light reflected from at least two angular directions. The first of these directions is the direction in which the beam reaches the object directly from the light source and is reflected directly to the detector by one of the retroreflector assemblies. The second of these angular directions is the direction in which the beam is reflected from the mirror in one or both of its travel paths from the source to the object and retroreflector and back to the detector.

Once the two angles at which the energy of the returning light decreases are determined, the position of the object relative to the two wheels of the display screen is easily determined.

The above-mentioned optical touch screen input W2 can be used for wood Kn people 0) related VJrl No. 49285 L'l (1983
(filed on May 9, 2013).

Although the systems described above have found wide acceptance in the industry, there remains room for further improvements. For example, this type of optical system always suffers from the loss of light within the device which substantially reduces the amount of light reaching the detector. To maximize the sensitivity and resolution of the instrument, it is necessary to maximize the actual amount of light energy and the contrast between the reflected light that is blocked by the object to be detected and the reflected light that reaches the directly opposing detector. It is desirable to increase . Therefore, any loss of available light within the target area of the device reduces both the resolution and sensitivity of the device, and such loss becomes increasingly significant as the target area becomes larger. As mentioned in the section above, in the above-mentioned devices that use a mirror as one of the reflecting surfaces, it is preferable to use a filter in front of the mirror to limit the reflected light to infrared wavelengths. is known. This avoids the undesirable effects of ambient light entering the working environment. However, the use of additional filters further contributes to light losses in the device.

Furthermore, as the overall size of the device increases, the mechanical tolerances for positioning and assembly of the parts of the touch screen device become increasingly stringent. That is, as the size of the mirror increases, it becomes increasingly difficult to produce a substantially flat and uniform mirror within desired tolerance limits. If the reflective properties of the mirror are not maintained within desired tolerance limits, the light reflected from the mirror will not be able to reach the opposing surface, resulting in reduced resolution and "blind spots" in the device. On the other hand, since retroreflective devices by their nature reflect light in the same direction as the incoming light, their precise positioning and mounting, along with maintaining tolerance limits during their fabrication, are not as stringent as for mirrors. Good too.

These optical positioners could be used with display screens up to 25 inches (diagonal) without significant light loss. However, it is now desirable to significantly increase the size of the device for use with display screens on the order of 10 feet (diagonal) in size. The problem of light loss within the target area is particularly acute in devices of such large size.

[Means for solving problems]

It is an object of the present invention to provide a new and improved optical positioning device.

More particularly, the object is to provide an optical positioning device that is capable of locating objects within a much larger target area than conventional devices.

A further object is to provide an optical positioning device that avoids the aforementioned problems.

In summary, the optical positioning device of the present invention comprises: a light emitting means; a light detection means for determining the level of light and emitting a signal corresponding thereto; a substantially rectangular target area; The light emitting means, the light detecting means, and the light directing means include a light source, a light detecting means, and a light directing means. a detector and a light directing means disposed at each of a first corner and a second corner along a common first side of the target area; further comprising a plurality of reflecting means disposed around the target area; Means includes first and second reflector assemblies facing inwardly on the target area to form second and third sides of the area, and oppositely facing the first side of the target area. a third reflector assembly forming a fourth side; Second. The third reflector assembly is made of retroreflective material.

The present invention will be explained in more detail based on preferred embodiments shown in the drawings.

Referring first to FIG. 1, an optical positioning apparatus according to the present invention is generally designated by the numeral 10. The device 10 maintains the parts of the device in proper relationship, and
A housing or frame assembly 12 is provided to protect these components from external dust and the like. The housing 12 is generally rectilinear in shape and defines a rectangular target area 14 within which the position of an object is to be determined.

This target area 14 is located at the first or top side 16 of the housing.
and by respective reflector assemblies designated 18, 20, 22 located along sides 19, 21 and 23 of housing 12. Reflector assembly 18
and 20 are provided along opposite second and third sides of target area 14 to define the sides, while reflector assembly 2
2 is provided along the fourth side of the target area 14 facing the first i2216 to define this side. According to a feature of the invention, these assemblies 18°20.22
each of which consists of a retroreflective +g material. A retroreflective material refers to a material that reflects light incident upon it substantially along the direct path of incidence.

According to another feature of the invention, a pair of similar optical distribution and detection assemblies 24,26 are provided on the first side 16 of the housing 12.
located adjacent to each corner formed at both ends of the That is, these assemblies 24, 26 have opposite sides 19.
21 and the first side 16.

Since these optical distribution and detection assemblies 24, 26 are identical, a description of their structure will be given only to assembly 24.

The assembly 24 is a light irradiation means.

That is, the light source 32. Detects the level of light irradiated there,
It comprises detection means 34° for emitting a corresponding signal and light directing means 36 for directing light from the light source into the target area 14. As can be seen, this directing means additionally directs the light returned from the target area 14 towards the detection means 34.

In further detail regarding the reflector assemblies 18, 20.22, as previously discussed, each reflector is made of retroreflective material. This retroreflective material reflects most of the light incident on the light-receiving surface within a predetermined angle range along the same path as the incident path. This predetermined angular range will hereinafter be referred to as the "set angular limit for retroreflection". If light is incident on the reflective surface outside this set angle limit, the rate cd of retroreflected light decreases rapidly.

In the illustrated embodiment, each retroreflector 18.20 is curved in a generally arcuate manner with respect to the frame 12 and the light distribution and detection assembly 24.26 so that the light incident from opposing light directing means 36 is the same. This ensures that the light is reflected back to the light directing means 36. In this regard, retroreflector 1
It will be clear that 8 retroreflects light only with respect to the light distribution and detection assembly 26 provided facing it. Similarly, retroreflector 20 retroreflects light with respect to an opposing light distribution and directing assembly 24 .

The remaining retroreflector 22 also consists of an arcuately curved strip of retroreflective material and is designed to ensure that all light received from both light distribution and directing assemblies 24, 26 is retroreflected. It is curved and positioned with respect to the bottom side 23.

In particular, the retroreflector 22 has the function of receiving and returning light from the light directing means 36 associated with each of the assemblies 24.26.

Objects 40, 42, 44, etc. within the target area are detected and located by geometrical methods, ie, bingometry. In determining this position 17, the optical distribution detector assembly 2
The relative angle of each object with respect to the detection means 34 of 4.26 is taken into account. These angular orientations are determined by providing scanning means for scanning the target area 14 and emitting signals over time relating to the angular orientation of each portion of the target area relative to a number of fixed reference points. . This reference point may include a corner in which each light distribution detection means 24,26 is located.

In FIG. 2, this scanning means is a frame 12.
It includes a housing 50 rotatably installed between the front and rear walls 13,15 of. In this case, the light directing means comprises a beam splitter 36 installed at an angle between the housing 50 and the target area 14, preferably 45°. As shown in FIG. 2, a light source 32 is provided pointing to one side of the beam splitter 36 and the light emitted therefrom is directed by a suitable lens into the beam splitter where it is bent substantially at right angles. and irradiates the target area. Light returning across target area 14 passes through beam splitter 36 and enters detector 34 . This detector is
In the example shown in FIG. 2, it is installed inside the housing 50 so as to rotate with it. A motor 52 is connected to rotate the housing 5o and the detector 34, and the first
The beam is configured to effectively scan the target area over a substantially 90' range, as shown by the beams intersecting the target area 14 at various angles in between. Preferably, an auxiliary lens 54 is provided to focus the beam returning from the target area to the detector 27i34.

Therefore, the return light that enters the housing 50 and impinges on the detector 34 at any given time is related to the relative angular position of the housing 50 at that time, thereby making the object 40
, 42.44 is determined. This is because the object causes a change in the light received by the detector 34 at that time.

FIG. 3 shows an alternative embodiment of the light distribution and detection device used in both assemblies 24, 26 instead of the example illustrated in FIG. In this embodiment, the same reference numerals are used with the suffix a for the parts corresponding to the embodiment of FIG. Similar to the previous example, the housing 50a is attached to the frame 12.
It is rotatably installed between the front and rear walls 13°15.

This housing is configured to rotate about a shaft 56 by a motor 52a attached to one side of the frame 12. A light source 32a is installed on one side of the housing 50a and directs a beam of light to the first hole 6 of the housing 50a.
0 and along main beam path 58. Beam splitter 36a is placed at a 45° angle between light source 32a and housing 50a, and light from light source 32a first passes through beam splitter 36a before reaching nosing 50a.

A mirror 62 is rotatably mounted within housing 50a therewith. This mirror 62 is placed at a substantially 45° angle relative to the frame 12 and deflects the light from the light source 32a substantially 90° and introduces it into the target area 14 as the housing rotates. The hole 60 is the rotating shaft 56
and the main beam path 58, so that even though the housing is rotated by the motor 56 and the angular orientation changes, the light from light #32a will still enter the housing and impinge on the mirror. The mirror 62 is the second mirror of the housing 50a.
The light is directed to the target area 14 through the aperture 64 of the target area 14 . The rotational speed of the housing 50a is sufficiently small compared to the speed of light that the light beam returning from the target area 14 substantially instantaneously re-enters the housing through the hole 64 and
It collides with the mirror 62. Mirror 62 deflects this return beam along the main beam path and directs it toward beam splitter 36a in the opposite direction to the beam emitted by light source 32a. Beam splitter 36a reflects approximately half of the energy of this return beam, indicated at 66, at a substantially 90° angle to impinge on detector 34a located externally of housing 50a.

The assemblies described in FIGS. 2 and 3 define only two types of configurations of light distribution and detection assemblies for use with the optical positioning device of the present invention.

However, other configurations of light distribution and detection assemblies may be used without departing from the invention, as long as the two assemblies are provided at opposite corners of frame 12, as shown in FIG. That will be understood.

The assembly shown in FIG. 3 is incorporated herein by reference in U.S. patent application Ser.
This is the subject of issue 31.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of an optical positioning device according to the present invention, FIG. 2 is a partially enlarged view of an embodiment of a light distribution and detection device related to FIG. 1, and FIG. 3 is a schematic plan view of an optical positioning device according to the present invention. 1 is a schematic diagram of an embodiment of a distribution detection device; FIG. 10-Optical positioning device 12-Housing (frame) 14-Target area 16-First side 18, 20. 22-Reflector assembly 19.21.
23 - side 24. 26 - light distribution detection assembly 28. 30 - corner 32 - light source (light irradiation means) 34 - detection means 36 - light directing means 40, 42. 44-Margin below object

Claims (1)

[Claims] 1. A linear frame assembly consisting of four sides defining a target area in which an object is to be positioned;
opposing detection means arranged to receive light from the target area, detecting a level of light and emitting a corresponding output signal; and opposing light directing means for directing light from the light source towards the target area. a pair of light distribution and detection assemblies installed at adjacent corners of said frame assembly formed by a pair of sides and one of the remaining sides; retroreflective means disposed about the periphery of said target area to reflect along a path; said retroreflective means arranged along a pair of opposite sides and one of the remaining sides of the target area; three retroreflective members; further associated with the detection means and configured to cause the presence of an object within the target area to appear to the detection means as a change in the intensity of the light at a given angular orientation; scanning means for determining an angular orientation of light with respect to the target area; whereby the position of an object within the target area is determined in two dimensions from the angular orientation of a change in intensity of light incident on the detection means; Optical positioning device determined by 2. The retroreflective member is arranged such that an incident angle of light from a light source provided adjacent to the second side of the pair of opposing sides falls within a predetermined angular limit for retroreflection. a first strip curved in an arc shape made of a retroreflective material disposed in relation to a first side of the pair of opposing sides; provided adjacent to the first side of the pair of opposing sides; a retroreflective material disposed in relation to a second side of the pair of opposing sides, the retroreflective material being disposed such that the angle of incidence of light from the light source is within predetermined angular limits for retroreflection; a second strip curved in the form of an arc consisting of; relative to said remaining sides arranged such that the angle of incidence of light from either of said light sources falls within the angular limits of the retroreflection setting; and a third arcuately curved strip of retroreflective material disposed in the same direction. 3. The apparatus of claim 1, wherein each of said light directing means has the function of directing reflected light received from said target area to an associated detection means. 4. The apparatus of claim 3, wherein each of said light directing means comprises a beam splitter. 5. each said light source is stationary and directs a beam of light toward said light directing means, thereby directing the beam in a first direction along a main beam path; drive means for rotating the housing about an axis of rotation; and reflecting means for redirecting a beam having radial energy into the housing; the housing being disposed substantially concentrically with the axis of rotation and the main beam path. a first hole having a radial energy, whereby a beam having radial energy from the light source is introduced into the housing through the first hole and impinges on the reflecting means, regardless of the rotation angle of the housing; Reflection means fixes the beam having radial energy within the housing and redirects it to the target area through a second hole provided in the housing; The beam of energy sweeps through the target area as the housing rotates at a predetermined speed; the speed of rotation is sufficiently small compared to the speed of light that the light is substantially transmitted through the second hole. momentarily re-entering the housing as a return beam and being reflected by the reflecting means along the main beam path through the first aperture in a second direction substantially opposite to the first direction; 2. Apparatus as claimed in claim 1, wherein said directing means is arranged to direct said return beam towards said detection means. 6. Light irradiation means; light detection means for detecting the level of light and emitting a signal corresponding thereto; means for defining a substantially rectangular target area; light from said light irradiation means is initially applied to said target area; an optical positioning device comprising: a light directing means for directing light returned from the target area to the detection means; The light irradiating means, the light detecting means, and the light directing means installed at each of a corner and a second corner are located at a first corner and a second corner provided along a common first side of the target area. a light source, a detection means, and a light directing means respectively disposed; further comprising a plurality of reflecting means arranged around the target area, the reflecting means being arranged on opposite second and third sides of the target area; and a third reflector assembly forming a fourth side of the target area opposite the first side; the first, second, and third reflector assemblies are retroreflective. A positioning device made from materials. 7. Each of said first and second reflector assemblies comprises a substantially continuous strip of retroreflective material, said strips having said light directing portions disposed closest to opposing sides. 7. Suitably curved to receive light from the means along the length of the associated side of said target area at an angle of incidence within set angular limits for retroreflection. equipment. 8. said third reflector assembly comprising a substantially continuous strip of retroreflective material, said strip directing light from said light directing means within set angular limits of incidence for retroreflection; 8. The device of claim 7, wherein the device is suitably curved at a corner to receive along the length of the fourth side of the target area. 9. The apparatus of claim 6, wherein each light directing means comprises a beam splitter. 10. Scanning means operatively associated with each said detection means for determining the angular orientation of the received light with respect to the target area, wherein the presence of an object within the target area is detected on the detection means at a particular angular orientation. 7. The device according to claim 6, which is configured to be recognized as a change in light intensity. 11. each said light source is stationary and directs a beam of light toward said light directing means, thereby directing the beam in a first direction along a main beam path; drive means for rotating the housing about an axis of rotation; and reflecting means for redirecting a beam having radial energy into the housing; the housing being disposed substantially concentrically with the axis of rotation and the main beam path. a first hole having a radial energy, whereby a beam having radial energy from the light source is introduced into the housing through the first hole and impinges on the reflecting means, regardless of the rotation angle of the housing; Reflection means fixes the beam having radial energy within the housing and redirects it to the target area through a second hole provided in the housing; The beam of energy sweeps through the target area as the housing rotates at a predetermined speed; the rotational speed is sufficiently small compared to the speed of light that the light passes through the second hole;
Substantially instantaneously, the return beam re-enters the housing and is reflected by the reflecting means along the main beam path through the first aperture in a second direction substantially opposite to the first direction. 11. Apparatus as claimed in claim 10, wherein said directing means is arranged to direct said return beam towards said detection means.