JP2010505178A - Optical touch panel - Google Patents

Abstract

An optical touch panel, wherein the panel comprises a support, and comprises a fiber optic illumination assembly disposed along and on at least a portion of the outer periphery of the support to define a detection area, the assembly comprising at least A light source arranged to send light along the at least one optical fiber, the panel comprising at least one photodetector, the photodetector in the detection region Configured to detect a change in light received from the fiber optic lighting assembly generated by the presence of an object, and the panel comprises a detection circuit, the detection circuit being at least from at least one photodetector. It receives one output and provides an output indication of the two-dimensional position of the intrusion of the object in the detection area.
[Selection] Figure 1A

Description

Reference to Related Applications Reference is made to US Provisional Patent Application Serial No. 60 / 827,223 entitled OPTICAL SENSING SYSTEM filed on September 28, 2006, the disclosure of which is incorporated herein by reference, 37 The priority thereof is claimed here in accordance with CFR 1.78 (a) (4) and (5) (i).

  Reference is made to US provisional patent application serial number 60 / 819,891 entitled “LOW PROFILE TRIANGULATION AND SYSTEMS CALIBRATION METHOD” filed July 12, 2006, the disclosure of which is incorporated herein by reference. Reference is made to US provisional patent application serial number 60 / 832,508 entitled “ACCUMULATOR BASED TRIANGULATION FOR TRACKING MULTIPLE EVENTS” filed on July 24, 2006, the disclosure of which is incorporated herein by reference. A reference is made to US provisional patent application serial number 60 / 889,746 entitled “TRIANGULATION WITH ENHANCED RESOLUTION” filed February 14, 2007, the disclosure of which is incorporated herein by reference.

  Reference is made to US patent application serial number 11 / 691,508 entitled OPTICAL SYSTEM filed March 27, 2007, the disclosure of which is incorporated herein by reference.

  Reference was made to US patent application serial number 11 / 691,510, entitled OPTICAL TOUCH SCREEN, filed March 27, 2007, the disclosure of which is incorporated herein by reference to 37 CFR 1.78 (a) ( Claim its priority here according to 4) and 5) (i).

  Reference was made to U.S. Patent Application Serial No. 11 / 776,563 entitled ILLUMINATION FOR OPTICAL TOUCH PANEL filed July 12, 2007, the disclosure of which is hereby incorporated herein by reference to 37 CFR 1.78 (a ) (4) and (5) (i) claim its priority here.

FIELD OF THE INVENTION The present invention relates generally to optical systems including optical fibers and optical light guides, and more particularly to optical touch panels and useful thereto. The present invention relates to an optical assembly.

BACKGROUND OF THE INVENTION The following US patent publications are believed to represent the state of the art: US Patents 7,099,553; 7,034,809; 6,972,401; 6,783,269; 5,257,340;

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved optical touch screen or touch panel.

  Thus, in accordance with a preferred embodiment of the present invention, an optical touch panel is provided, the optical touch panel having a support, the optical touch panel being along at least a portion of a peripheral edge of the support. And a fiber optic illumination assembly disposed thereon and defining a detection region, the assembly including at least one optical fiber having a core and a cladding, the at least one optical fiber being a transverse defining a circumference. The at least one optical fiber has at least one discontinuity for scattering light at at least one position along the surface, the at least one optical fiber in at least one light transmissive region The optically transparent region has a refractive power and has a focal point located close to the discontinuity. And the assembly includes a light source arranged to transmit light along the at least one optical fiber, the optical touch panel having at least one photodetector, the photodetector Is configured to detect a change in light, the change in light being generated by the presence of an object in the detection region, received from the fiber optic lighting assembly, and the optical touch panel Has a detection circuit, which receives at least one output from the at least one photodetector and provides an output indication of the two-dimensional position of the intrusion of the object into the detection area To do.

  Preferably, at least one discontinuity that scatters the light has an angular range of less than 10 percent of the outer periphery and the at least one light transmissive region has an angular range of greater than 25% of the outer periphery. .

  Preferably, a refractive power in the at least one transmissive region of the at least one optical fiber and at least one discontinuity that scatters the light are received from the light source along the at least one optical fiber and In a plane extending light that is scattered by the at least one discontinuity that scatters the light directly from the at least one discontinuity, through the cladding, and generally away from the at least one discontinuity. It functions to generally go to. Additionally or alternatively, the at least one light transmissive region is located generally opposite the at least one discontinuity that scatters the light with respect to an outer periphery of the at least one optical fiber.

  Preferably, the at least one optical fiber extends along at least most of the outer periphery of the light curtain area, and the at least one discontinuity that scatters the light extends along the outer periphery. , Generally direct the light in a plane and fill the inside of the outer periphery, thereby defining the interior light curtain. Additionally, the optical touch panel may also include at least one light curtain intrusion sensor that senses intrusions in the light curtain and provides two-dimensional intrusion location information. The optical touch panel may operate to generate an intrusion output signal including, and the optical touch panel may include an output signal processing circuit for providing an output indication of the intrusion position in two dimensions.

  Preferably, the at least one optical fiber extends along at least most of the outer periphery of the light curtain region, and the at least one discontinuity that scatters the light includes a plurality of discontinuities that scatter the light. The plurality of discontinuities are distributed along the outer periphery, whereby the plurality of discontinuities that scatter the light generally direct the light into a plane, and the inside of the outer periphery. And thereby together define the light curtain inside.

  Preferably, the light scattering function of the at least one discontinuity varies along the length of the at least one optical fiber to provide compensation for attenuation produced by the optical fiber. In addition, at least one discontinuity that scatters the light having a function of changing the light scattering by the refractive power in the at least one light transmissive region of the at least one optical fiber and at least one optical fiber. The light received from the light source along and scattered by the at least one discontinuity that scatters light directly from the at least one discontinuity and generally away from the at least one discontinuity It is generally directed in a plane extending in the direction and functions so that the light has a generally uniform intensity.

  Preferably, the at least one optical fiber has an aspheric cross section and the at least one discontinuity is precisely located at the focal point of the at least one light transmissive region. In addition, the refractive power of at least one optical fiber having an aspheric cross section and at least one light transmissive region, and at least scatters light precisely located at the focal point of the at least one light transmissive region. A discontinuity received from the light source along the at least one optical fiber and scattered by the at least one discontinuity that scatters the light directly from the at least one discontinuity through the cladding, at least It functions to generally face in a plane of uniform thickness extending generally away from one discontinuity.

  Preferably, the detection circuit operates at least in part by triangulation.

  Preferably, the at least one optical fiber extends along three sides of the detection region, the at least one detector has a pair of detectors, the detectors at adjacent corners of the detection region, Located alongside both ends of the at least one optical fiber, and the detection circuit operates at least in part by triangulation.

  In accordance with another preferred embodiment of the present invention, an optical touch panel is provided, the optical touch panel having a support that defines a generally flat surface, the optical touch panel comprising optical illumination. And a light illumination assembly disposed along and on at least a portion of the outer periphery of the support to define a detection region, the assembly including at least one light guide. The at least one light guide has at least one light scatterer, the at least one light guide having a refractive power at at least one surface, the surface being proximate to the light scatterer; At least one having a focal point located and the assembly being arranged to send light along at least one light guide The light power of the at least one light guide and the at least one light scatterer received from the at least one light source along the at least one light guide and scattered by the at least one light scatterer. Is generally directed in a plane parallel to a generally flat surface, the optical touch panel having at least one photodetector, the photodetector detecting a change in light The light change is generated by the presence of an object in the detection area and received from the light illumination assembly, and the optical touch panel has a detection circuit and the detection The circuit receives at least one output from at least one photodetector and provides an output indication of the two-dimensional position of the intrusion of the object into the detection area It is intended.

  Preferably, the at least one light guide extends along at least most of the outer periphery of the light curtain region parallel to the generally flat surface, and the at least one light scatterer is along the outer periphery of the light curtain region. Extending to provide a generally uniform distribution of light in the plane, filling the inside of the outer perimeter of the light curtain region and thereby defining a light curtain therein. In addition, the optical touch panel may also include at least one light curtain intrusion sensor that senses intrusions in the light curtain and provides two-dimensional intrusion location information. The optical touch panel is operable to generate an intrusion output signal including, and the optical touch panel may include an output signal processing circuit for providing an output indication of a two-dimensional intrusion position.

  Preferably, the at least one light guide comprises a single light guide, and the at least one light source has two light sources, and a single light source is disposed at each end of the single light guide. Is done. Additionally or alternatively, the at least one light source is located only at the corners of the outer periphery of the detection area.

  Preferably, the light scattering function of the at least one light scatterer varies along the length of the at least one light guide to provide compensation for the attenuation produced by the light guide.

  Preferably, the detection circuit operates at least in part by triangulation.

  Preferably, the at least one light guide extends along three sides of the detection area, the at least one detector has a pair of detectors, which are adjacent corners of the detection area. At least one light guide located side by side, and the detection circuit is at least partially activated by triangulation.

  Preferably, the at least one light guide has an aspheric cross section and the at least one light scatterer is precisely located at the focal point of the at least one surface. Additionally, the aspheric cross section may include a curved forward portion with refractive power. Additionally, the aspheric cross section may include a generally parallel intermediate portion. Additionally, the aspheric cross section may include a tapered rear portion that meets a relatively narrow rear strip.

  Preferably, the optical touch panel also includes a guide that defines an elongated transparent mounting portion and a window, the guide being fixed to a support, and the guide that defines the elongated transparent mounting portion and the window. Has a U-shaped cross section with parallel surfaces, and the parallel surfaces engage a generally parallel intermediate portion.

  Preferably, the at least one light scatterer includes a layer of paint that scatters light.

  Preferably, the optical touch panel also includes a guide that defines an elongated transparent mounting portion and a window portion, and the guide is fixed to the support. Additionally, an elongated transparent mounting portion and a guide defining the window portion may function to ensure correct placement of the light illumination assembly relative to the support. Additionally or alternatively, a guide defining an elongated transparent mounting and window has a U-shaped cross section. Additionally or alternatively, a guide that defines an elongate transparent mounting and window serves to minimize the reduction of light from the at least one light guide.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and interpreted more fully from the following detailed description taken in conjunction with the drawings in which:

1A and 1B are simplified views of a touch panel constructed and operative in accordance with two alternative preferred embodiments of the present invention. 1A and 1B are simplified views of a touch panel constructed and operative in accordance with two alternative preferred embodiments of the present invention. 2A, 2B, 2C, and 2D are simplified, partially cross-sectional, and partially pictorial views of a portion of a fiber optic assembly useful in the touch panel of FIG. 1A, respectively. 2A, 2B, 2C, and 2D are simplified, partially cross-sectional, and partially pictorial views of a portion of a fiber optic assembly useful in the touch panel of FIG. 1A, respectively. 2A, 2B, 2C, and 2D are simplified, partially cross-sectional, and partially pictorial views of a portion of a fiber optic assembly useful in the touch panel of FIG. 1A, respectively. 2A, 2B, 2C, and 2D are simplified, partially cross-sectional, and partially pictorial views of a portion of a fiber optic assembly useful in the touch panel of FIG. 1A, respectively. 2E, 2F, 2G, and 2H are simplified, partially cross-sectional, and partially pictorial views of a portion of an optical assembly useful in the touch panel of FIG. 1B, respectively. 2E, 2F, 2G, and 2H are simplified, partially cross-sectional, and partially pictorial views of a portion of an optical assembly useful in the touch panel of FIG. 1B, respectively. 2E, 2F, 2G, and 2H are simplified, partially cross-sectional, and partially pictorial views of a portion of an optical assembly useful in the touch panel of FIG. 1B, respectively. 2E, 2F, 2G, and 2H are simplified, partially cross-sectional, and partially pictorial views of a portion of an optical assembly useful in the touch panel of FIG. 1B, respectively. FIG. 3 is a simplified diagram of an optical fiber assembly structure useful in the touch panel of FIG. 1A and providing attenuation compensation. 4A and 4B are simplified cross-sectional views of the optical fiber assembly structure of FIG. 3 taken along lines IVA-IVA and IVB-IVB, respectively. 4A and 4B are simplified cross-sectional views of the optical fiber assembly structure of FIG. 3 taken along lines IVA-IVA and IVB-IVB, respectively. FIG. 5 is a simplified diagram of another fiber optic assembly structure that is useful in the touch panel of FIG. 1A and that provides attenuation compensation. FIG. 6 is a simplified cross-sectional view of the optical fiber assembly structure of FIG. 5 taken along line VI-VI. FIG. 7 is a simplified diagram of an optical assembly structure useful in the touch panel of FIG. 1B and providing attenuation compensation. 8A and 8B are simplified cross-sectional views of the optical assembly structure of FIG. 7 taken along lines VIIIA-VIIIA and VIIIB-VIIIB, respectively. 8A and 8B are simplified cross-sectional views of the optical assembly structure of FIG. 7 taken along lines VIIIA-VIIIA and VIIIB-VIIIB, respectively.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Reference is now made to FIGS. 1A and 1B. These show an optical touch panel 100 that is constructed and operates in accordance with a preferred embodiment of the present invention. As seen in FIGS. 1A and 1B, the touch panel 100 has an optical illumination assembly 102 that extends along and on all or part of the outer periphery of the support 104. Preferably, the support 104 is typically a glass plate. Alternatively, the glass plate may be removed, and the support 104 may be a frame (not shown). Typically, the fiber optic illumination assembly 102 extends along three of the four edges of the detection region 105 that are generally planar.

  In accordance with a preferred embodiment of the present invention, an optical illumination 102 receives illumination from a light source 106. The light source 106 is an LED or diode laser or the like, preferably an infrared laser or LED, disposed at each end 108 of the assembly 102. Alternatively, a single light source 106 may be used, which can be placed at one end 108 of the assembly 102. As seen in FIGS. 1A and 1B, the light source 106 is preferably located at the corner of the outer periphery of the detection region 105, which is generally planar.

  According to a preferred embodiment of the present invention, as shown in FIG. 1A, the light illumination assembly 102 has at least one light guide 110, which is a plastic optical fiber commercially available from Mitsubishi. An optical fiber 111 having a core 112 and a cladding 114, such as an ESKA, having a circular cross section. The cladding 114 preferably has at least one light scatterer (light scatterer) 116 and is at least one position along it, preferably at least one light transmission of the light guide 110. The light guide 110 has optical power in the discontinuous portion that scatters light on the opposite side of the light region 117.

  In the embodiment shown in FIG. 1A, the light scatterer 116 is preferably shaped by forming a scratch that extends throughout the cladding 114 along at least a majority of the total length of the fiber optic lighting assembly 102. . The scratch is not necessarily required, but may enter the core 112.

  In the embodiment shown in FIG. 1B, the light illumination assembly 102 has at least one light guide 110, such as a plastic rod, and is in at least one position along it, preferably at least one light transmission of the light guide 110. It is preferable to have at least one light scatterer 116 on the opposite side of the active region 117, in which the light guide 110 has optical power. The surface of the light guide 110 in the transmissive region 117 preferably has a focal point located close to the light scatterer 116.

  In the embodiment shown in FIG. 1B, the light scatterer 116 is shaped by a narrow strip of white paint that extends along a plastic rod along at least most of the total length of the light illumination assembly 102. It is preferred that

  According to a preferred embodiment of the present invention, the at least one light scatterer 116 acts to scatter light that is received from the light source 106 and passes through the at least one light guide 110. As the refractive power of the light guide 110 in at least one light transmissive region 117 is generally indicated by reference numeral 118, the scattered light is collimated in a direction generally away from the scatterer 116. ) And make them go. It will be appreciated that generally all locations in the detection region 105 that are generally planar receive light from generally all locations along the at least one light transmissive region 117.

  According to a preferred embodiment of the present invention, the at least one light guide 110 extends generally continuously along the outer perimeter of the light curtain area defined by the detection area 105 and at least one light scatterer 116 is provided. Extending generally continuously along the outer perimeter, directing light generally into a plane, filling the inside of the outer perimeter, and thereby defining a light curtain therein.

  In an alternative embodiment, the at least one light guide 110 extends along the outer periphery of the light curtain region defined by the detection region 105, and the at least one light scatterer 116 is along the outer periphery. Distributed, so that the plurality of light scatterers generally directs light into a plane, fills the inside of the outer periphery, and thereby together Define the interior light curtain.

  The impingement of an object, such as a stylus or a finger 120, onto the support 104 is preferably sensed by one or more photodetectors 122, which extend from the light illumination assembly 102. Preferably, it is arranged along the edge (edge) of the non-detection area 105. The detector detects a change in light received from the light illumination assembly 102 (generated by the presence of a finger 120 in the detection region 105). Preferably, the detector 122 is located in the same plane as the light illumination assembly 102. Preferably, two detectors are sufficient to detect the finger 120 everywhere in the detection region 105, and as shown, each detector is located at an adjacent corner of the detection region 105, and Cover at least 90 degrees.

  The detectors 122 are each preferably a linear CMOS sensor, such as the RPLIS-2048 linear image sensor commercially available from One Technology Place, Homer, Panavision SVI, LLC, New York, LLC, which are triangulated ( It is suitable for use in triangulation. The output of the detector 122 is provided to a detection circuit 124, which may include applicant's US Patent Application Publication 2006/0187198, and US Provisional Application 60 / 819,891; 60 / 832,508, and 60 / 889,746 (these The disclosure of which is incorporated herein by reference) and provides an output indication of the two-dimensional position of the intrusion of the finger 120 in the detection region 105.

  Reference is now further made to FIGS. 2A, 2B, 2C and 2D. These are each a simplified, partially cross-sectional, partially pictorial view of a portion of an optical assembly useful in the touch panel of FIG. 1A.

  FIG. 2A shows the use of an optical fiber 200 having a circular cross-section and having a core 212 and a cladding 214, which is a plastic optical fiber commercially available from Mitsubishi. And so on, having a discontinuity 216 in the form of a longitudinal scratch that passes through the cladding 214 and into the core 212. In this case, the surface 220 shaped by scratches scatters light into the core. A curved light transmissive region 222 lying on the opposite side of the discontinuity 216 has refractive power and, as shown, the direction away from the discontinuity 216 (shown by arrow 226). ) Generally in a plane 224 extending to).

  FIG. 2B illustrates the use of an optical fiber 230, which has a circular cross-section, a core 232, and a cladding 234, ESKA, a plastic optical fiber commercially available from Mitsubishi. ) And the like, and has a discontinuity 236 in the form of a longitudinal scratch that passes through the cladding 234 and does not necessarily have to enter the core 232 Also good. In this case, a light scattering material 235, such as a white paint, fills at least a portion of the longitudinal scratch, and the material 235 and the surface 240 defined by the scratch scatter light. A curved cross-sectional surface 242 opposite the discontinuity 236 has refractive power and, as shown, disperses scattered light away from the discontinuity 236 (shown by arrows 246). In the extending plane 244, it generally acts to collimate.

  The discontinuity that scatters light has an angular range of less than 10 percent of the outer periphery of the fiber, more preferably an angular range of less than 1 percent, and at least one light transmissive region is 25% of the outer periphery It is a particular feature of the present invention to have an angular range greater than. This feature results in a light curtain with a generally uniform thickness.

  FIG. 2C illustrates the use of an unprecedented optical light guide 250 having an aspheric cross section 252 that is longitudinally located at a focal point 258 of the aspheric cross section 252. It has a discontinuity 256 in the form of a scratch. In this case, the surface 260 defined by the scratch scatters light. The curved light transmissive region 262 on the opposite side of the discontinuity 256 has a refractive power and, as shown, moves scattered light away from the discontinuity 256 (indicated by arrow 265). It acts to collimate into a generally parallel beam. It will be appreciated that cladding (not shown) may be applied to the outer periphery of the light guide 250.

  FIG. 2D illustrates the use of an unprecedented optical light guide 270 having an aspheric cross section 272 that is in the form of a longitudinal scratch located at the focal point 278 of the aspheric cross section 272. And has a discontinuity 276. In this case, a light scattering material 280, such as a white paint, fills at least a portion of the longitudinal scratch, and the material 280 and the surface 282 defined by the scratch also scatter light. A curved light transmissive region 284 on the opposite side of the discontinuity 276 has a refractive power and, as shown, moves scattered light away from the discontinuity 276 (indicated by arrow 285). It acts to collimate into a generally parallel beam. It will be appreciated that cladding (not shown) may be applied to the outer periphery of the light guide 270.

  The discontinuity that scatters light has an angular range of less than 10 percent of the outer periphery of the fiber, more preferably an angular range of less than 1 percent, and at least one light transmissive region is 25% of the outer periphery It is a particular feature of the present invention to have an angular range greater than. This feature results in a light curtain with a generally uniform thickness. Due to the cross-sectional configuration of the optical light guides 250 and 270 where the discontinuities 256 and 276 are precisely located at the respective focal points of the light transmissive regions 252 and 272, a light curtain of very uniform thickness can be realized. .

  Reference is now further made to FIGS. 2E, 2F, 2G and 2H. Each of these is a simplified, partially cross-sectional, partially pictorial view of a portion of an optical assembly useful in the touch panel of FIG. 1B.

  FIG. 2E illustrates the use of a light guide 300, which has an aspheric cross-sectional configuration and at least one light scatterer that is precisely located at the focal point of the light transmissive region. Yes. As shown in FIG. 2E, the cross-section of the light guide 300 has a light-transmissive curved front portion 302 with refractive power, generally parallel intermediate portions 304 and 306, and a relatively narrow rear strip. ) Preferably includes rear portions 308 and 310 that are tapered at portion 312. Preferably, the strip 312 is coated with a layer of white paint 314 that scatters light along all or most of its extent. It will be appreciated that the light guide 300 may be formed by any suitable manufacturing technique such as extrusion.

  The curved forward portion 302 is generally opposite the band-like portion 312 and, as shown, in a plane 324 that extends light scattered by the layer 314 away from the layer 314 (shown by arrow 326). Generally acts to collimate.

  FIG. 2F illustrates the use of an alternative example of a light guide 330 that includes an aspheric cross-sectional configuration and at least one light scatterer that is precisely located at the focal point of the light transmissive region. And have. As shown in FIG. 2F, the light guide 330 has a cross-section along a refractive optically transparent curved forward portion 332, generally parallel intermediate portions 334 and 336, and all or most of its extent, And a back portion 338 formed with a relatively narrow layer 340 of white paint that scatters light. It will be appreciated that the light guide 330 may be formed by any suitable manufacturing technique such as extrusion.

  The curved forward portion 332 is generally on the opposite side of the layer 340 and, as shown, in a plane 344 extending in a direction away from the layer 340 (indicated by arrow 346) away from the light scattered by the layer 340. Generally acts to collimate.

  FIG. 2G illustrates the use of a light guide 350, which is similar to the light guide 300 (FIG. 2E) and is accurately positioned at the aspheric cross-sectional configuration and the focus of the light transmissive region. And at least one light scatterer. As shown in FIG. 2G, the cross-section of the light guide 350 includes a light-transmissive curved front portion 352 having refractive power, generally parallel intermediate portions 354 and 356, and a relatively narrow rear strip. It preferably includes a tapered rear portion 358 and 360 that meet at 362. Preferably, the strip 362 is coated with a layer of white paint 364 that scatters light along all or most of its area. It will be appreciated that the light guide 350 may be formed by any suitable manufacturing technique such as extrusion.

  The curved forward portion 352 is generally opposite the band-like portion 362 and, as shown, in a plane 374 that extends light scattered by the layer 364 away from the layer 364 (shown by arrow 376). It generally acts to collimate.

  According to a preferred embodiment of the present invention, the light guide 350 is located within a member 377 (preferably having a U-shaped cross section) defining an elongated transparent mounting and window. Retained. Member 377 is typically secured to a support, such as support 104 (FIG. 1). The structure of FIG. 2G ensures correct alignment of the light guide 350 with respect to the support 104 so that the collimated scattered light indicated by reference numeral 118 in FIG. Oriented in parallel. This alignment is further enhanced by the parallel surfaces defined by the intermediate portions 354 and 356 engaging the corresponding parallel surfaces 378 and 379 at the member 377. In addition, the structure of FIG. 2G eliminates light loss from the light guide 350 that may have occurred due to light coupling by bonding of the light guide 350 on the support 104 or other types of attachment. Minimize. The member 377 is particularly useful in an optical touch panel structure as providing a seal on the outer periphery of the touch panel.

  FIG. 2H illustrates the use of an alternative example of a light guide 380 that includes an aspheric cross-sectional configuration and at least one light scatterer that is precisely located at the focal point of the light transmissive region. And have. As shown in FIG. 2H, the cross-section of the light guide 380 is along a refractive optically transparent curved forward portion 382, generally parallel intermediate portions 384 and 386, and all or most of its extent. And a rear portion 388 formed with a relatively narrow layer 390 of white paint that scatters light. It will be appreciated that the light guide 380 may be formed by any suitable manufacturing technique such as extrusion.

  The curved forward portion 382 is generally opposite the layer 390 and, as shown, in a plane 391 that extends light scattered by the layer 390 in a direction away from the layer 390 (shown by arrow 392). Generally acts to collimate.

  According to a preferred embodiment of the present invention, the light guide 380 is held within a member 393 (preferably having a U-shaped cross section) that defines an elongated transparent mounting and window. Member 393 is typically secured to a support, such as support 104 (FIG. 1). The structure of FIG. 2H ensures correct alignment of the light guide 380 with respect to the support 104 so that the collimated scattered light indicated by reference numeral 118 in FIG. Oriented in parallel. This alignment is further enhanced by the parallel surfaces defined by the intermediate portions 384 and 386 engaging the corresponding parallel surfaces 394 and 395 at the member 393. In addition, the structure of FIG. 2H may result in loss of light from the light guide 380 (which may have occurred due to light coupling by bonding or other types of attachment of the light guide 380 onto the support 104). Minimize. The member 393 is particularly useful in an optical touch panel structure as providing a seal on the outer periphery of the touch panel.

  Very uniform thickness due to the cross-sectional configuration of the optical light guides 300, 330, 350 and 380 (a configuration in which the light scatterers are precisely located at the respective focal points of the light-transmitting front part having refractive power) Light curtains can be realized.

  Reference is now made to FIGS. 3, 4A and 4B. These are simplified views of an optical fiber assembly structure 400 that is useful in the apparatus of FIG. 1A and that provides attenuation compensation. The optical fiber 410 is associated with a light source 412 at one end. One or more discontinuities 416 are formed in the optical fiber 410 as generally described above. In FIG. 3, it can be seen that the discontinuities 416 can have different depths or widths depending on their location along the fiber 410. For example, the portion 420 of the discontinuity 416 at a position relatively far from the light source 412 shown in FIG. 4A is more than the portion 430 of the discontinuity 416 at a position relatively close to the light source 412 shown in FIG. 4B. It can also be seen that it has a large width and depth.

  Alternatively or additionally, as shown in FIGS. 5 and 6, the discontinuity 506 may be composed of separate discontinuity portions 508 spaced apart from each other, the density of which is It can be seen that the position 510 relatively far from the light source 512 is larger than the position 514 relatively close to the light source 512.

  As a result of the discontinuity changing over the length of the fiber, such as discontinuities 416 (FIG. 3) and 506, the attenuation of light traveling along the fiber from the light source at one end of the fiber is compensated for, This means that a generally uniform level of illumination is produced over the length of the illumination area of the fiber optic assembly structure.

  Reference is now made to FIGS. 7, 8A and 8B. These are simplified views of an optical assembly structure 600 that is useful in the apparatus of FIG. 1B and that provides attenuation compensation. The light guide 610 is associated with the light source 612 at one end thereof. One or more light scatterers 616 are formed in the light guide 610 as generally described above. In FIG. 7, it can be seen that the light scatterers 616 can have different depths or widths depending on the location along the light guide 610. For example, the portion 620 of the light scatterer 616 at a position relatively far from the light source 612 shown in FIG. 8A is more than the portion 630 of the light scatterer 616 at a position relatively close to the light source 612 shown in FIG. It can also be seen that it has a large width and depth.

  As a result of the light scatterer changing over the length of the light guide 610, the light illumination assembly is compensated for by the attenuation of light traveling along the light guide 610 from the light source 612 at one end of the light guide 610. This means that a generally uniform level of illumination is produced over the length of the illumination area of the structure 600.

  Those skilled in the art will appreciate that the present invention is not limited by what has been particularly shown and described hereinabove. Rather, the scope of the present invention encompasses both combinations and subcombinations of the features recited in the claims, as well as non-prior art modifications that would occur to those skilled in the art upon reading the above description.

Claims (31)

An optical touch panel,
The optical touch panel has a support,
The optical touch panel has a fiber optic illumination assembly disposed along and on at least a portion of the outer periphery of the support to define a detection area;
The assembly includes at least one optical fiber having a core and a cladding, the at least one optical fiber having a cross section defining an outer periphery, wherein the at least one optical fiber is in at least one position along it. Having at least one discontinuity for scattering light, the at least one optical fiber having refractive power in at least one light transmissive region, wherein the light transmissive region is proximate to the discontinuity. Has a focal point located, and
The assembly includes a light source arranged to transmit light along the at least one optical fiber;
The optical touch panel has at least one photodetector, and the photodetector is configured to detect a change in light, and the change in light is determined by the presence of an object in the detection area. Generated and received from the fiber optic lighting assembly; and
The optical touch panel includes a detection circuit, which receives at least one output from the at least one photodetector, and detects a two-dimensional position of an object intrusion into the detection area. Provide an output display,
The optical touch panel.   The at least one discontinuity that scatters light has an angular range of less than 10 percent of the outer periphery, and the at least one light transmissive region has an angular range greater than 25% of the outer periphery. Item 4. The optical touch panel according to Item 1.   A refractive power in the at least one transmissive region of the at least one optical fiber and at least one discontinuity that scatters the light is received from the light source along the at least one optical fiber and transmits the light. Light scattered by the at least one discontinuity to be scattered is generally directed directly into the plane extending away from the at least one discontinuity, through the cladding, and generally away from the at least one discontinuity. The optical touch panel as set forth in claim 1, wherein the optical touch panel functions so as to be moved.   The optical touch panel of claim 3, wherein the at least one light transmissive region is located generally opposite the at least one discontinuity that scatters the light with respect to an outer periphery of the at least one optical fiber.   The at least one optical fiber extends along at least most of the outer periphery of the light curtain region, and the at least one discontinuity that scatters the light extends along the outer periphery, generally transmitting light in a plane. The optical touch panel according to claim 1, wherein the optical touch panel is directed to fill an inside of the outer peripheral edge, thereby defining a light curtain therein.   The optical touch panel also includes at least one light curtain intrusion sensor that senses an intrusion in the light curtain and generates an intrusion output signal that includes two-dimensional intrusion position information. The optical touch panel according to claim 5, wherein the optical touch panel includes an output signal processing circuit for providing an output display of a two-dimensional intrusion position.   The at least one optical fiber extends along at least most of the outer periphery of the light curtain region, and the at least one discontinuity that scatters light includes a plurality of discontinuities that scatter light; The plurality of discontinuities are distributed along the outer periphery, whereby the plurality of discontinuities that scatter the light generally direct the light into a plane and fill the inside of the outer periphery. The optical touch panel of claim 1, and thereby together define a light curtain therein.   The optical touch panel of claim 1, wherein the light scattering function of the at least one discontinuity varies along the length of the at least one optical fiber to provide compensation for attenuation produced by the optical fiber.   The refractive power in the at least one light transmissive region of the at least one optical fiber and at least one discontinuity that scatters the light having the function of changing light scattering are along the at least one optical fiber. The light received from the light source and scattered by the at least one discontinuity that scatters the light directly from the at least one discontinuity, through the cladding, generally from the at least one discontinuity. 9. The optical touch panel as claimed in claim 8, wherein the optical touch panel is generally directed in a plane extending away and functions so that the light has a generally uniform intensity.   The optical of claim 1, wherein the at least one optical fiber has an aspheric cross section and the at least one discontinuity is precisely located at the focal point of the at least one light transmissive region. Touch panel. The refractive power of the at least one optical fiber having an aspheric cross section and the at least one light transmissive region, and the light precisely located at the focal point of the at least one light transmissive region are scattered. At least one discontinuity,
Light received from the light source along the at least one optical fiber and scattered by the at least one discontinuity that scatters the light directly from the at least one discontinuity through the cladding and to the at least one The optical touch panel of claim 10, wherein the optical touch panel functions to generally face in a plane of uniform thickness extending generally away from the two discontinuities.   The optical touch panel of claim 1, wherein the detection circuit operates at least in part by triangulation. The at least one optical fiber extends along three sides of the detection region, the at least one detector has a pair of detectors, and the detectors are located at adjacent corners of the detection region. , Located side by side at both ends of the at least one optical fiber, and
The optical touch panel of claim 1, wherein the detection circuit operates at least in part by triangulation. An optical touch panel,
The optical touch panel has a support that defines a generally flat surface,
The optical touch panel includes a light illumination assembly, the light illumination assembly being disposed along and on at least a portion of the outer periphery of the support to define a detection area;
The assembly includes at least one light guide, the at least one light guide has at least one light scatterer, and the at least one light guide has refractive power at at least one surface; The surface has a focal point located close to the light scatterer; and
The assembly includes at least one light source arranged to transmit light along the at least one light guide, the refractive power of the at least one light guide and the at least one light scatterer comprising: Function to direct light received from the at least one light source along at least one light guide and scattered by the at least one light scatterer generally in a plane parallel to the generally flat surface. ,
The optical touch panel has at least one photodetector, and the photodetector is configured to detect a change in light, and the change in light is determined by the presence of an object in the detection area. Generated and received from the light illumination assembly; and
The optical touch panel includes a detection circuit, which receives at least one output from the at least one photodetector, and detects a two-dimensional position of an object intrusion into the detection area. Provide an output display,
The optical touch panel.   The at least one light guide extends along at least most of the outer periphery of the light curtain region parallel to the generally flat surface, and the at least one light scatterer is on the outer periphery of the light curtain region. The optical system of claim 14, extending along, providing a generally uniform light distribution in the plane, filling an inner periphery of the light curtain region and thereby defining a light curtain therein. Touch panel.   The optical touch panel also includes at least one light curtain intrusion sensor that senses an intrusion in the light curtain and generates an intrusion output signal that includes two-dimensional intrusion position information. 16. The optical touch panel according to claim 15, wherein the optical touch panel has an output signal processing circuit for providing an output display of a two-dimensional intrusion position. The at least one light guide comprises a single light guide; and
The at least one light source has two light sources, and a single light source is disposed at each end of the single light guide;
The optical touch panel according to claim 14.   The optical touch panel according to claim 14, wherein the at least one light source is located only at a corner portion of an outer peripheral edge of the detection region.   The light scattering function of the at least one light scatterer varies along the length of the at least one light guide to provide compensation for attenuation produced by the light guide. Optical touch panel.   The optical touch panel of claim 14, wherein the detection circuit is at least partially activated by triangulation. The at least one light guide extends along three sides of the detection region, the at least one detector has a pair of detectors, and the detectors are adjacent corners of the detection region. Are arranged side by side at both ends of the at least one light guide, and
The optical touch panel as claimed in claim 14, wherein the detection circuit operates at least in part by triangulation.   The optical touch panel of claim 14, wherein the at least one light guide has an aspheric cross section, and the at least one light scatterer is accurately located at a focal point of the at least one surface.   The optical touch panel as set forth in claim 22, wherein the aspherical cross section includes a curved front portion, and the front portion has refractive power.   24. The optical touch panel of claim 23, wherein the aspheric cross section includes a generally parallel intermediate portion.   25. The optical touch panel as claimed in claim 24, wherein the aspheric cross section includes a tapered rear portion that meets a relatively narrow rear strip.   The optical touch panel also includes a guide that defines an elongated transparent mounting portion and a window, the guide being fixed to the support, and the guide that defines the elongated transparent mounting portion and the window. 25. The optical touch panel of claim 24, having a U-shaped cross section with parallel surfaces, and wherein the parallel surfaces engage the generally parallel intermediate portion.   The optical touch panel according to claim 14, wherein the at least one light scatterer includes a layer of paint that scatters light.   The optical touch panel according to claim 14, wherein the optical touch panel further includes a guide that defines an elongated transparent mounting portion and a window portion, and the guide is fixed to the support.   29. The optical touch panel of claim 28, wherein the elongate transparent mounting portion and the guide defining the window portion function to ensure correct placement of the light illumination assembly relative to the support.   29. The optical touch panel according to claim 28, wherein the elongated transparent mounting portion and the guide defining the window portion have a U-shaped cross section.   29. The optical touch panel as claimed in claim 28, wherein the elongate transparent mounting portion and the guide defining the window portion function to minimize light reduction from the at least one light guide.

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