CA1094371A - Remote control light transmitting lens system - Google Patents
Remote control light transmitting lens systemInfo
- Publication number
- CA1094371A CA1094371A CA342,982A CA342982A CA1094371A CA 1094371 A CA1094371 A CA 1094371A CA 342982 A CA342982 A CA 342982A CA 1094371 A CA1094371 A CA 1094371A
- Authority
- CA
- Canada
- Prior art keywords
- transmitter
- light
- lens
- remote control
- side surfaces
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Led Device Packages (AREA)
- Optical Communication System (AREA)
Abstract
Abstract of the Disclosure A light transmitting lens for a light activated television remote control system is disclosed. The lens has a modified cylindrical shape to provide a wide horizontal dispersion angle and a reduced vertical dispersion angle.
Description
37~.
This application is a divisional of copending application Serial No. 257 526 filed July 22, 1976 in the name of The Magnavox Company.
The invention relates to a light transmitter capable of being used in a television remote control system, and to a lens forming part of the transmit-ter.
Remote control systems for operating a television receiver are well known in the art. The operator initiates a command from a hand held trans-mitter. The transmitted command is usually a burst of ultrasonic energy or light energy which is directed toward the television receiver. The television receiver is equipped with a receiver for capturing the transmitted ultrasonic or light energy. This receiver provides an electrical signal which is de-coded into a command which additional circuitry executes.
In one type of system for remotely controlling a television, a single ultrasonic frequency corresponds to each remotely controlled function or com-mand. The receiver detects the presence of this signal and executes the com-mand. Ultrasonic transmitters are efficienl: and the signal path loss is low.
The ultrasonic signals are strongly reflected by many room surfaces. Thus, ultrasonic systems are not particularly sbnsitive to transmitter orientation with respect to the receiver. Ultrasonic noise is present, however, in most home environments. Thè use of home appliances which emit ultrasonic energy may initiate a false command in a system where a single frequency is used to initiate a command. A single frequency command system also makes impractical a larger number of function conmands. Digital coding techniques in ultrasonic systems are not practical because of the reflections and propagation time of ` acoustic energy in an air medium.
Light activated remote control systems overcome some of the dis-advantages of ultrasonic systems but have distinct disadvantages of their own, e.g., line of sight propagation and substantial path loss. Because light , -1-.
'~
~0~13~
energy has a lower propagation time than ultrasonic energy, and a wider use-able bandwidth, more functions may be defined and controlled than in ultra-sonic systems. A pulse coding scheme also increases the noise immunity over a system which detects only the presence of a single frequency. Light energy however is subjectto a much greater path loss than ultrasonic energy.
Additionally, transducers which convert electrical signals into light energy are not as efficient as their ultrasonic counterparts. To overcome the losses sustained by the light remote control link, it has been necessary to intro-duce more directivity into the remote control link than is found in the ultra-sonic system. The operator must ta~e care in aiming the transmitting sourcetoward the light receiver. Since television styling restrictions limit the size of the light receiver aperture, the receiver gain is further limited thus making aiming of the transmitter at the receiver more critical. The present invention reduces the directivity requirement of previous light activated remoted control systems without compromising the system reliability.
According to the present invention, there is provided a transmitter for transmitting light comprising a lens formed of optical material having a front light transmitting surface, said front surface being cylindrical about an axis, said axis being located rearwardly of said front surface, side sur-faces, a top surface, and a bottom surface, and further comprising a lightemitting diode located within said optical material.
~` In a preferred embodiment the front surface is part cylindrical about an axis of curvature, the sub surfaces are planar and converge toward a line located rearwardly of the front surface and the top and bottom sur-faces are planar and converge toward a line located rearwardly of the front surace.
A light emitting diode (IED) is used to convert electrical energy ,~-2-~"
"~
;, ' ' 37~
into light energy. Since the dispersion pattern of commercially available LEDs are usually too narrow or too broad for use in light activated remote control systems, a modified cylindrical lens is used to shape $he dispersion -2a-~`.
:
.
~0~371 pattern of an LED. The resulting dispersion pattern is broad in the horizontal plane to overcome operator difficulty in horizontally aiming the transmitter towards the receiver. Since in the past it has been determined that horizontal aiming is more difficult to achieve than vertical aiming, the energy content in the horizontal plane is increased at the expense of the vertical plane thus improving the performance of the light transmitter.
The dispersion pattern for the lens is controlled by altering the angle of the sidewalls. Further tr~lsmitter efficiency is achieved by directly bond-ing the LED to the lens thus removing losses which occur when an air surface 10 exists between two optical mediums. The transmitter will work well with a number of rece`ivers. One such receiver is described in a copending application serial no. 257 522 filed on the same date as the present application in the name of Eugene P. Mierzwinski and entitled Remote Control Light Receiver.
The invention together with that of pending application Serial No.
257 526, will now be described in greater detail with reference to the accom-paning drawings, in which:
Figure 1 is a perspective view of a light transmitter incorporating the invention.
Figure 2 is a diagrammatic view of a light emitting diode used to convert electrical signals into light energy in the transmitter of Figure 1.
Figure 3 is a horizontal sectional view, taken on line 3-3 of Figure 1, o the light transmitter illustrating the horizontal light dispersion of the transmitter.
Figure 4 is a vertical sectional view, taken on line 4-4 of Figure 1, of the light transmitter illustrating the vertical light dispersion of the transmitter.
Referring to Figure 1, the transmitter comprises a lens 11 for shap-ing the radiation pat~ern of a light emitting diode ~LED) 12. The lens 11 has ~- -3 :
~9~3~
a convex part cylindrical surface 13 having an axis of curvature 139 which forms the object side of the lens 11. The cylindrical lens front 13 produces a line focus as shown. Positioning the LED between the focus and cylinder sur-face 13 changes the light dispersion. Further control of the dispersion angle of the lens is achieved by converging the surfaces 1~, 15 subtending the cylindrical arc. These surfaces 14, 15 are coated with a reflective material 24. Light incident to the surface is reflected out the fron~ lens surface 13.
~ithout the reflective coating~ light incident to these surfaces 14, 15 at an angle greater than the critical angle would pass through the surfaces and not reach the remote control reciever. The angle these surfaces 14, 15 make with each other aid in determining the vertical dispersion angle of the trans-mitter. The walls 16, 17 subtending the length of the cylindrical face 13 also converge towards a line to the rear o~ the front surface 13. They are similarly coated with a reflective material and shape the horizontal disper-sion pattern. The lens material is *Plexiglas having an index of refraction of 1.36 at a wavelength o 940 nm. Other ~laterials will suggest themselves to those skilled in the art.
The LED 12 is located in a hole in the rear surface 18 of the lens 11. The preferred location for the LED 12 was experimentally determined to be in front of the lens ~ocus. The LED 12 is bonded to the lens 11 with a clear epoxy having an index of refraction substantially the same as the index of refraction of lens 11. This reduces losses which would otherwise occur with an air interface between the LED 12 and the lens 11. Referring to Figure
This application is a divisional of copending application Serial No. 257 526 filed July 22, 1976 in the name of The Magnavox Company.
The invention relates to a light transmitter capable of being used in a television remote control system, and to a lens forming part of the transmit-ter.
Remote control systems for operating a television receiver are well known in the art. The operator initiates a command from a hand held trans-mitter. The transmitted command is usually a burst of ultrasonic energy or light energy which is directed toward the television receiver. The television receiver is equipped with a receiver for capturing the transmitted ultrasonic or light energy. This receiver provides an electrical signal which is de-coded into a command which additional circuitry executes.
In one type of system for remotely controlling a television, a single ultrasonic frequency corresponds to each remotely controlled function or com-mand. The receiver detects the presence of this signal and executes the com-mand. Ultrasonic transmitters are efficienl: and the signal path loss is low.
The ultrasonic signals are strongly reflected by many room surfaces. Thus, ultrasonic systems are not particularly sbnsitive to transmitter orientation with respect to the receiver. Ultrasonic noise is present, however, in most home environments. Thè use of home appliances which emit ultrasonic energy may initiate a false command in a system where a single frequency is used to initiate a command. A single frequency command system also makes impractical a larger number of function conmands. Digital coding techniques in ultrasonic systems are not practical because of the reflections and propagation time of ` acoustic energy in an air medium.
Light activated remote control systems overcome some of the dis-advantages of ultrasonic systems but have distinct disadvantages of their own, e.g., line of sight propagation and substantial path loss. Because light , -1-.
'~
~0~13~
energy has a lower propagation time than ultrasonic energy, and a wider use-able bandwidth, more functions may be defined and controlled than in ultra-sonic systems. A pulse coding scheme also increases the noise immunity over a system which detects only the presence of a single frequency. Light energy however is subjectto a much greater path loss than ultrasonic energy.
Additionally, transducers which convert electrical signals into light energy are not as efficient as their ultrasonic counterparts. To overcome the losses sustained by the light remote control link, it has been necessary to intro-duce more directivity into the remote control link than is found in the ultra-sonic system. The operator must ta~e care in aiming the transmitting sourcetoward the light receiver. Since television styling restrictions limit the size of the light receiver aperture, the receiver gain is further limited thus making aiming of the transmitter at the receiver more critical. The present invention reduces the directivity requirement of previous light activated remoted control systems without compromising the system reliability.
According to the present invention, there is provided a transmitter for transmitting light comprising a lens formed of optical material having a front light transmitting surface, said front surface being cylindrical about an axis, said axis being located rearwardly of said front surface, side sur-faces, a top surface, and a bottom surface, and further comprising a lightemitting diode located within said optical material.
~` In a preferred embodiment the front surface is part cylindrical about an axis of curvature, the sub surfaces are planar and converge toward a line located rearwardly of the front surface and the top and bottom sur-faces are planar and converge toward a line located rearwardly of the front surace.
A light emitting diode (IED) is used to convert electrical energy ,~-2-~"
"~
;, ' ' 37~
into light energy. Since the dispersion pattern of commercially available LEDs are usually too narrow or too broad for use in light activated remote control systems, a modified cylindrical lens is used to shape $he dispersion -2a-~`.
:
.
~0~371 pattern of an LED. The resulting dispersion pattern is broad in the horizontal plane to overcome operator difficulty in horizontally aiming the transmitter towards the receiver. Since in the past it has been determined that horizontal aiming is more difficult to achieve than vertical aiming, the energy content in the horizontal plane is increased at the expense of the vertical plane thus improving the performance of the light transmitter.
The dispersion pattern for the lens is controlled by altering the angle of the sidewalls. Further tr~lsmitter efficiency is achieved by directly bond-ing the LED to the lens thus removing losses which occur when an air surface 10 exists between two optical mediums. The transmitter will work well with a number of rece`ivers. One such receiver is described in a copending application serial no. 257 522 filed on the same date as the present application in the name of Eugene P. Mierzwinski and entitled Remote Control Light Receiver.
The invention together with that of pending application Serial No.
257 526, will now be described in greater detail with reference to the accom-paning drawings, in which:
Figure 1 is a perspective view of a light transmitter incorporating the invention.
Figure 2 is a diagrammatic view of a light emitting diode used to convert electrical signals into light energy in the transmitter of Figure 1.
Figure 3 is a horizontal sectional view, taken on line 3-3 of Figure 1, o the light transmitter illustrating the horizontal light dispersion of the transmitter.
Figure 4 is a vertical sectional view, taken on line 4-4 of Figure 1, of the light transmitter illustrating the vertical light dispersion of the transmitter.
Referring to Figure 1, the transmitter comprises a lens 11 for shap-ing the radiation pat~ern of a light emitting diode ~LED) 12. The lens 11 has ~- -3 :
~9~3~
a convex part cylindrical surface 13 having an axis of curvature 139 which forms the object side of the lens 11. The cylindrical lens front 13 produces a line focus as shown. Positioning the LED between the focus and cylinder sur-face 13 changes the light dispersion. Further control of the dispersion angle of the lens is achieved by converging the surfaces 1~, 15 subtending the cylindrical arc. These surfaces 14, 15 are coated with a reflective material 24. Light incident to the surface is reflected out the fron~ lens surface 13.
~ithout the reflective coating~ light incident to these surfaces 14, 15 at an angle greater than the critical angle would pass through the surfaces and not reach the remote control reciever. The angle these surfaces 14, 15 make with each other aid in determining the vertical dispersion angle of the trans-mitter. The walls 16, 17 subtending the length of the cylindrical face 13 also converge towards a line to the rear o~ the front surface 13. They are similarly coated with a reflective material and shape the horizontal disper-sion pattern. The lens material is *Plexiglas having an index of refraction of 1.36 at a wavelength o 940 nm. Other ~laterials will suggest themselves to those skilled in the art.
The LED 12 is located in a hole in the rear surface 18 of the lens 11. The preferred location for the LED 12 was experimentally determined to be in front of the lens ~ocus. The LED 12 is bonded to the lens 11 with a clear epoxy having an index of refraction substantially the same as the index of refraction of lens 11. This reduces losses which would otherwise occur with an air interface between the LED 12 and the lens 11. Referring to Figure
2, the overall olltline of the LED is shown. The lead wires 19 supply electri-cal current to the junction of the diode. The diode is encapsulated in a lens cap 20. When the lens cap 20 is bonded to the lens 11 a continuous optical medium is formed. As noted above, this structure minimizes losses that would occur with air between different optical surfaces.
* Trade mark :~ ;
379~
Figure 3 illustrates the transmitter operation in the horizontal plane.
Llght originating from the LED 12 which is incident to the side walls 16J 17 is reflected out the front of the lens. The transmitter angle of dispersion is controlled by the angle between surfaces 14, 15 and the location of the LED.
Positioning the LED forward of the focus minimizes the effect of the LED
position on the dispersion angle.
Figure 4 illustrates the operation of the lens in the vertical plane. The surface 16, 17 control the transmitter horizontal dispersion angle in a method similar to that of surfaces 14, 15 of Figure 3. By re-- 10 ducing the angle between surfaces 14~ 15 the vertical dispersion angle is reduced. Since the transmitter vertical location with respect to the re-ceiver location is restricted, it is desirable to restrict the vertical dispersion in favor of distributing more energy in the horizontal dispersion angle. Those skilled in the art will recogrlize tother energy dispersion pat-terns which this invention may be readily modified to produce.
The following specifications are given by way of example only of one embodiment of a light transmitter. Specifics for other applications will be obvious to those skilled in the art.
~ Cylinder radius 7/16"
Cylinder width 5/8"
Overall length 5/8"
Rear surface LxW 1/4" x 1/4"
LED type *GE 55C
Lens material *Plexiglas LED distance to front surface 1/2"
* Trade marks
* Trade mark :~ ;
379~
Figure 3 illustrates the transmitter operation in the horizontal plane.
Llght originating from the LED 12 which is incident to the side walls 16J 17 is reflected out the front of the lens. The transmitter angle of dispersion is controlled by the angle between surfaces 14, 15 and the location of the LED.
Positioning the LED forward of the focus minimizes the effect of the LED
position on the dispersion angle.
Figure 4 illustrates the operation of the lens in the vertical plane. The surface 16, 17 control the transmitter horizontal dispersion angle in a method similar to that of surfaces 14, 15 of Figure 3. By re-- 10 ducing the angle between surfaces 14~ 15 the vertical dispersion angle is reduced. Since the transmitter vertical location with respect to the re-ceiver location is restricted, it is desirable to restrict the vertical dispersion in favor of distributing more energy in the horizontal dispersion angle. Those skilled in the art will recogrlize tother energy dispersion pat-terns which this invention may be readily modified to produce.
The following specifications are given by way of example only of one embodiment of a light transmitter. Specifics for other applications will be obvious to those skilled in the art.
~ Cylinder radius 7/16"
Cylinder width 5/8"
Overall length 5/8"
Rear surface LxW 1/4" x 1/4"
LED type *GE 55C
Lens material *Plexiglas LED distance to front surface 1/2"
* Trade marks
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A transmitter for transmitting light comprising a lens formed of optical material having a front light transmitting surface, said front surface being cylindrical about an axis, said axis being located rearwardly of said front surface, side surfaces, a top surface, and a bottom surface, and further comprising a light emitting diode located within said optical material.
2. The transmitter of claim 1 wherein said side surfaces are planar and converge toward a line located rearwardly of said front surface.
3. The transmitter of claim 2 wherein said top and bottom surfaces are planar and converge toward a line located rearwardly of said front sur-face.
4. The transmitter of claim 2 further comprising a reflective coating covering at least a portion of each of said side surfaces adjacent said front surface.
5. The transmitter of claim 2 further comprising a reflective coating covering each of said side surfaces.
6. The transmitter of claim 3 further comprising a reflective coating covering each of said side surfaces, said top surface and said bottom sur-face.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA342,982A CA1094371A (en) | 1975-10-28 | 1980-01-03 | Remote control light transmitting lens system |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US626,164 | 1975-10-28 | ||
| US05/626,164 US4009394A (en) | 1975-10-28 | 1975-10-28 | Remote control light transmitter employing a cylindrical lens |
| CA257,526A CA1075057A (en) | 1975-10-28 | 1976-07-22 | Remote control light transmitting lens system |
| CA342,982A CA1094371A (en) | 1975-10-28 | 1980-01-03 | Remote control light transmitting lens system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094371A true CA1094371A (en) | 1981-01-27 |
Family
ID=27164570
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA342,982A Expired CA1094371A (en) | 1975-10-28 | 1980-01-03 | Remote control light transmitting lens system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1094371A (en) |
-
1980
- 1980-01-03 CA CA342,982A patent/CA1094371A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1075057A (en) | Remote control light transmitting lens system | |
| CA1092400A (en) | Remote control light receiver | |
| KR102134178B1 (en) | Friend or foe identification system and method | |
| CA2197916C (en) | Optical transmitter and transceiver module for wireless data transmission | |
| US4709412A (en) | Remote control unit integrator console | |
| JP2002517002A (en) | Directional object sensor for automatic flow controllers | |
| WO2019028948A1 (en) | Optical phased array-based laser radar transceiver antenna and distance measurement method | |
| US4556280A (en) | Single cable optical fibre signaling system | |
| CN104868950B (en) | Infrared launcher, infrared remote-control device, infrared light emission and method of reseptance | |
| CA1094371A (en) | Remote control light transmitting lens system | |
| WO2009052652A1 (en) | Lighting device and method with indication | |
| CN113267856A (en) | Transmitting-receiving coaxial compact laser transmitting-receiving device | |
| CA2166256C (en) | Optical signal transceiver for use with diffusely transmitted optical radiation | |
| CN110244414A (en) | A kind of optical module | |
| CN212485359U (en) | Infrared emitting diode device | |
| CN111868590B (en) | Transmitting-receiving optical device, optical module and communication equipment | |
| JPS6384329A (en) | Remoto control device | |
| CN115602079A (en) | Aerial imaging system and man-machine interaction system based on aerial imaging | |
| JP3694155B2 (en) | Optical transceiver | |
| US6684034B2 (en) | Optical signal receiving device | |
| US5841154A (en) | Light-emitting diode device with reduced scatter | |
| US4909586A (en) | Two-way connector | |
| JPS6211538B2 (en) | ||
| JPS6123427A (en) | Information transmitter | |
| TWI728726B (en) | Infrared emitting diode device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |