CA1179766A - Television monitoring system - Google Patents
Television monitoring systemInfo
- Publication number
- CA1179766A CA1179766A CA000441721A CA441721A CA1179766A CA 1179766 A CA1179766 A CA 1179766A CA 000441721 A CA000441721 A CA 000441721A CA 441721 A CA441721 A CA 441721A CA 1179766 A CA1179766 A CA 1179766A
- Authority
- CA
- Canada
- Prior art keywords
- unit
- camera
- remote control
- light
- control apparatus
- 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
Abstract
ABSTRACT OF THE DISCLOSURE
A remote controlled television monitoring system for both day and low light level condition monitoring. The monitoring system includes a dual channel camera unit, a passive transmitter unit, and a receiver unit interposed between the transmitter unit and the remotely located camera unit. The transmitter provides control signals to a video control circuit in the receiver unit which controls the positioning of the camera unit as well as the camera lens functions. The dual channel camera unit is mounted on a pan-tilt unit; and includes a day-light, camera, a low-light camera, a light intensifier for the low-light camera, and a channel control circuit. The channel control cir-cuit provides for automatic channel switching in response to light intensity variations. This circuit also provides automatic control of the light intensifier during low-light operation.
A remote controlled television monitoring system for both day and low light level condition monitoring. The monitoring system includes a dual channel camera unit, a passive transmitter unit, and a receiver unit interposed between the transmitter unit and the remotely located camera unit. The transmitter provides control signals to a video control circuit in the receiver unit which controls the positioning of the camera unit as well as the camera lens functions. The dual channel camera unit is mounted on a pan-tilt unit; and includes a day-light, camera, a low-light camera, a light intensifier for the low-light camera, and a channel control circuit. The channel control cir-cuit provides for automatic channel switching in response to light intensity variations. This circuit also provides automatic control of the light intensifier during low-light operation.
Description
1~ 7'~7~
BAC~G~OUND OF T~E INVENTION
This is a divisional application of Canadian Application No. 368,196 filed January 9, 1981.
The present invention relates to a remote controlled closed circuit television monitoring system, and in particular to a monitoring system that is adapted to low-light level operation .
A major problem with previous monitoring systems of this type concerns the life o~ the light intensLfier, which is used to enhance or increase the light received at the camera lens during night operation. Due to the sophisti-cated technology involved, the cost of the light intensifier constitutes a significant portion of the total cost of the system. In many monitoring systems, a single camera is employed and the light intensifier is permanently affixed or glued to the face of the camera. Thus, the intensifier will be utilized any time the camera is operational, day or night.
It is also apparent that when the intensifier needs to be replaced, the television camera must also be replaced. In other single camera systems where the intensifier is not directly attached, a motorized mirror or other similar devices must be employed in order to remove the intensifier frorn the path between the lens and camera for day operation.
Another factor affecting the life of the intensi~-ier is the amount of light entering the intensifier. An over-load situation may occur if the ambient light intensity is beyond an acceptahle limit for the light intensifier. 'rhis situation has been controlled previously with neutral density filters and lens iris control, or with manual intensifier gain control.
1 m ~
11'7~76~j Regarciing the transmission of control signals to the television camera, an inherent shortcoming in previous systems concerns the distance range available between the transmitter unit and receiver unit. ln many systems, a power supply is contained in the transmitter unit, and a separate wire is supplied for each control signal to be transmitted to -the receiver. Due to the nurnber and gauge of the wires involved and the sensitivity of the relays in the receiver unit, the distance between the transmitter and receiver is quite limited. This result is counter to the purposes of a remote controlled television monitoring system.
S~MMARY OF TE~E INVENTION
Briefly stated, the present invention consti-tutes an improvement for a remote control apparatus in a television monitoring system having a transmitter unit for providing control signals, a camera unit for providing avideo signal, a receiver unit in association with the transmitter unit and the camera unit, and at least one ac-tuator for controlling the camera unit in response to the control signals.
The improvement comprises a source of d.c. voltage electrical power for the transmitter unit, contained in the receiver unit, and connected to the transmitter unit via a pair of conductors; a single conductor for transmitting two of the control signals from the transmitter unit to the receiver unit; and a video corltrol circuit means, contained in the receiver unit, for selectively utilizing the two control signals, -transmitted alternatively on the single conductor, to energize the actuator.
dm~
3L ~ 7t~7~i Other objects, fea-tures and advan-tages of the present invention will become apparent from the subsequent description and examples, and the appended claims taken in conjunction with the accompanying drawinqs.
BRIFF DFSCRIPTION OF T~IE DRAllINGS
Figure 1 is a perspective view o~ the mon:itorincJ
system according to the present invention, including the camera unit, the pan-tilt unit, the receiver unit, -the passive transmitter unit, and -the monitor uni-t.
Figure 2 is a top elevation view of the dual channel camera unit.
Figure 3 is a block diagram of the channel control circuit contained in the camera unit.
Figure 4 is a circuit diagram of the channel control circuit contained in the camera unit.
Figure 5 is a perspective view of the receiver unit.
Figure 6 is a block diagram of the receiver circuit shown in Figure 5.
~0 Figure 7 is a circuit diagram of the receiver circuit shown in Figure 5.
Figure 8 is a circuit diagram of a video control circuit which comprises a por-tion of the rece:iver circuit.
ms~ ,~
:1*~ 6~
DETAILED DESCRIPTION O~ THF PREFE RED E~IBODIME.~T
Referring to Figure l, a perspective view o~ a television monitoring system 10 according to the present invention is shown. The monitoring system is generally ~- comprised of a dual channel camera unit 12, a pan-tilt unit 14, a receiver un;t 16, a passive transmitter unit 18, and a television monitor unit: 19. The camera unit is mounted on the pan-tilt unit, allowing for the controlled positioning of the camera unit in the horizontal and vertical directions. The operation of the system is con-trolled from the passive transmitter. Control signals are sent from the passive transmitter, through cable 17, to the receiver. The signals are then processed through the various video control circuits in the receiver, and sent to the camera and pan-tilt units. As indicated by the break in cable 17, the passive transmitter is typically located remote from the receiver. According to the present invention, the passive transmitter may be located up to 30,000 feet from the receiver, using number 22 wire for the wires contained in cable 17. The transmitter unit 18 is referred to as "passive" because the transmitter does not contain a separate power supply. The electrical power required by the transmitter is provided by a power supply contained in thc receiver. This power supply also provi~les the electrical power needed to operatc the camera unit.
The video output signal from the camera unit 12 is transmitted by cable 21 to the remote te]evision monitor l9. Typically, the monitor 19 and transmieter 18 are 1 1'7976~i locate(l in the same place so that the person viel~ing the picture on t1le n~onitor screen can also operate the trans-mitter and thus move or adjust the camera unit 12.
- Preferably a lO inch or 12 inch monitor unit manufactured by Audio Tronics~ lnc., Minneapolis, Minnesota is used for the monitor 19, but any equivalent or other conventional unit can be utili~ed.
The front face 20 of the passive transmitter contains a number of operational or video controls. The on/off switch 22 is used to provide electrical power to camera unit 12. This switch as well as the remaining four switches are three position lever switch (nonlocking on both sides). The auto/manual switch 24, pan speed potentio-meter 26, and joystick 28 control the operation of the pan-tilt unit 14. In the automatic mode, the pan-tilt unit sweeps or pans the camera unit horizontally left and right within the boundaries determined by the adjustable limit switches contained in the pan-tilt unit. ln the manual mode, the camera unit is ordinarily stationary. I-lolvever, the position of the camera unit may be altered in the vertical or horizontal direction under the control of joystick 28. The joystick is generally comprised of a two position switch for each direction of movement (left, right, up, down), and is standard in thc art. Pan sl~ecd potentiometer 26 is used to vary the speed of the camera unit in the horizontal direction from 0.0 to 8.0 degress per second. Zoom switch 30, focus sw-itch 32, and ;ris switch 3~ are used o control the operation of the monitori~ed lens in the camera unit. Pan-tilt unit 14 is 37~
of a standard type manuf~ct-lred by Quic~-Set, Inc., Northbrook, Illinois. It is capable of panning from 0 to 340 degrees horizontally, and tilting fro,n 45 degrees ahove to 45 degrees below horizont~l. The pan-tilt unit may be mounted on any suitable structure ~hich will permit the desired camera unit scanning range, such as pole 35.
Referring to Figure 2, a top elevation view of - dual channel camera unit 12 is shown. The camera unit includes two separate television cameras, a day-light camera 36 and a low-light camera 38. Both cameras are manufactured by Panasonic, with the day-light carnera iden-tified as model No. llOOA and the low-light camera i~enti-fied as Model lOOOA. Each camera provides a separate video channel, generally designated as a day channel (day-light lS camera 36) and a night channel (low-light camera 38). T}le day channel is used when the ambient light intensity on faceplate 39 is between 10,000 foot candles (full sunlight) and 1.0 foot candle (daybreak). When the ambient light is reduced to approximately 1.0 foot candles (dusX) the night channel will be utilized. The night channel will typically be operated over a range in light intensity from 1.0 foot candles to 0.00001 foot candles (overcast night).
In addition to low-light camera 38, the night channel also includes light intensifier 40, relay lenscs 42, and motorized lens 44. T}le l;ght intcnsificr is mann-factured by Varo Electron l)eviccs, Inc., Garland, 'le~as and is characterizcd as a 25mm image intens;fier witll il 180K gain. The light intensifier 40 is used to en}lllncc or increase the light received at lens 44. The motorizcd lens 44 is man-lfactured ~y Vicon, Inc., ~'eli Yor~, Ne~ 'or~.
11 ~97~6 It is characterizcd as an l8-144mm zoom lens on a 1 format with a minimum f/stop of 2.0 giving a 25-200mm zoom range on a 2/3 format. The relay lenses 42 co~prise two con-ventional 50mm lenses(f 1.43 and are spaced apart slightly as shown.
- The day channel is comprisel of day-light camera 36 and motorized-lens 46, and is mounted substantially parallel to the n;ght channei components. Motorized lens 46 is identical ~o motorized lens 44 in the night channel.
It should be appreciated that this separation of the day and night channels not only increases the life of the intensifier, but also provides crisper day channel picturc,s.
This is due to the elimination of the light intensifier and relay lens from the day channel.
Circuit board 48 contains the channel control circuit 54 (which is described in more detail with refer-ence to Figures 3 and 4). As indicated from the front face 20 of transmitter 18, there is no provision for manually switching the camera channels. This function is performed automatically by the channel control circuit 54. The cir-cuit board 48 is connected (via a conventional edge connector) to a connector circuit board 49. The connector board 49 brings the video and electrical signals into the circuit board 48 and also relays the video output signal to 1he monitor 19. Jacks/sockets 50 ancl 51 are used to connect , the video si~nal cables 5() and 51 frolll the two tel(~vision cameras 36 and 38 with circuit board 49 ancl in turn Witl the control circuit 54. Plugs/sockets 41 and 43 are ~ISC?~
to connect the electrical power via cal)1es 41 anl 4:i to the two cameras 36 and 38. Jack-socket 45 is usel to connect the vicleo output si~nal from the camera 12 ~via circuit boarcl 49) throu~h cable 21 to the exterll~l Vi(Wi :l t7'~76~
monitor ]9. The connoctor board 43 also has a terminal block 47 on one edge whicll connects the circuit bosrds 48 and 49 to reeeiver 16 v;a socket 37 ancl cable 29.
The light intensifier 40 is conl,ectl3c3 as by p]-lg 33 ancl appropriate wiring to the connector boarcl 49 throu5h tormirlal 47. ~lotorized lenses 44 and 46 are conrl(Jcted to circuit borlr(l 48 by jacks/sockets 25 and 27 and cables 25' and 27'.
The camera ~init 12 also contains a therMostatically controlled 100 watt res-istive-ceramic type heater 58 (mounted in the front of eamera unit 12 under the motorized lenses 44 and 46), and a 115 VAC fan 53 which provides eontinuous air circulation whenever power is supplied to the camera unit.
The heater is controlled by thermostat 96 and is adapted to be automatieally switehed on at 55F and switched off at 65"F.
The heater 58 and fan 53 are connected to eireuit board 49 through terminal block 47.
All of the heretofore mentioned devices contained in the camera unit 12 are modularly mounted in housing 55. The low-light camera 38 is attached to one of the relay lenses 42 as one unit and the light intensifier 40, motorized lens 44 and other relay lens are also attached together as a second unit, and each of these units can be takon out and replaced as a unit, or the separate items can l)e detached in the camera 12 and replaced indiv;dually. Brackets 57 and 59 are attrlclled to the bottom 61 of the housing 55 and llold the low-lir~?lt camera units in place. The light in~ensifier /10 is attached tas hy screws) to ul-right portion of bracket 57, while brac~et 59 is adapted to slide over camera 38 and secure it in place by means of two screws 69. The screws 69 are made of a plastic material, such as Delrin1r, to eliminrlte ground loops which would cause a noisy video sigllrll. Similarly, the day-light camera 36 and motorized lens 46 are attached tor~ether as a unit or individnally. The overhanring portion of bracket 57 a Tre~d~3 llarl;
97~6 is attachc(l nlso by plastic screws 69 to camera 36 and secures this latter two-colnponent unit in place. This nlodul.ll mourl~illg arrangelllerlt, as well as the plug/sockct and jack/socket conllec-tions~ uleaJI.s that all of the comporlerlts may ~JC readily rcmoved S and replaccd without taking dowrl tne camerLI urlit 12 itself.
Ilousing 55 also provides a weather-tight seal which ~rosists the entry of moisture into the unit. A cover member 6S
is adapted to fit over the bottorn meMber 61 and is held tightly in plaee by conventional fasteners 65.
Referring to Figure 3, a block diagram of channel control circuit 54 is shown. This circuit performs two basic functions, channel switching control and light intensifier eontrol. As stated previously, the switehing from one channel to another occurs automatically. This switching is based on a variation in the amb;en~ light intensity, as sensed by photocell 56 mounted on receiver unit 16 ~best shown in Figure 5).
The signal from photoeell 56, as with the other signals sent from the reeeiver to the eamera unit, enter at input terminal 58. The voltage signal from the photocell is compared via comparator 60 with a reference voltage supplied by trans-former and regulator 62. The reference voltage is selected so that the comparator 60 will generate a high output volta~e at dusX and a low output voltage at daybrea~, on line 64. l'hc output from the comparator 60 is connected on two relay a~
ZS timing cireuits. I,ine 64 is directly connecte-l to tl)e low-light camera power relay and time delay circuit 66, an(l indirectly connected througll invertor 68 to day-lig)lt camela power relay and time delay eircuit 70. Circuits 66 and 70 arc used to turn off and on tlle eloctrical power to the two carneras.
Thus, when the output of the comparator sw;tches high at dus~, a relay in circuit 66 will be actuate(1, and l)ower will be supplied to the low-light ealllera. Similar]y, inverter 68 will generate a low OUtpllt to circuit 70 whon the c-mr,lr.ltor outrllt 1179~6t, res~ollses to tl~e comparator output do not occur simul~all-eously. In both circuits 66 and 70, a time delay capacitor is provided to allow the camera being energized to warm up ~or stabilize before the other camera is de-energized. Thus, in the situation above the day-light camera would remain on for approximately 60 seconds after the low-light camera ~as turned on. When the day-light camera is turned ofE, the actuation of the relay in circuit 70 will set the out-put, line 72, of flip flop 74. This will activate a relay in circuit 76 to transfer the motorized lens power and control, as well as video output of the camera unit, to the new channel. In the situation above, the video output would be that of the night channel, and motorized lens 44 would be operational. It should be appreciated that as day-break occurs, the day channel will be supplied with po~er and control in the same manner as described for the night channel.
The second function of channel control circuit 54 is to control the gain of the light intensifier durin~ night channel operation. This control is based upon photocell 78.
This photocell is mounted near the inside surface of face plate 39 of the camera unit 12. The voltage signal from the photocell 78 is connected to light intensifier control cir-cuit 80. This circuit is used to vary the voltage sent ~o the light intensifier control 82 and thereby control the gain.
This intensifier control 82 also acts to provide automatic overload protection of the intensifier. Thus as the arllhient .
-~ ~.7~7~i~
light increases with the approach of daybreak, or a high intensity source of light impinges on the intensifier, the light will not o~erload the intensifier as is possible with manual control.
Referrin~ to Figure 4, a circu;t diagram of the channel control circuit in Figure 3 is shown. Transformer and regulator block 62 is now shown to be comprised of step down trnasformer 86 and regulator 88. Transformer 86 provides t~o 7.5 VAC secondary outputs, and along Wit}l diodes Dl and D2 and capacitor Cl, an approximate 12 VDC
1~ voltage is supplied across lines 90 and 9Z. Regulator 88 is a National Semiconductor LM340T regulator, and it supplies an 8VDC output voltage. This output is connected to two voltage dividers RlR2 and R3R4. These resistors set an upper and lower "trip" point for comparator 60, an LM339 IC manufactured by National Semiconductor. Capacitor C2 provides the time delay in day-light camera power relay and time delay circuit 70, and capacitor C3 provides the time delay for circuit 66. Relay Kl is the power relay for the day-ligllt camera, and relay K2 is the power relay for the low-light camera. Each relay has two sets of con-tacts, the first being used to set or reset flip flop 74 and the second being used to energize or de-energi~e the cameras. Flip flop 74 is an L~555 Timer manufactured by National Semicondllctor. The o~ltpUt of thc flip f~op, line 72, is connec-ted to relay K3. Relay K3 is used to transfer the lens power and control, as well as the ~ideo signal output from the camera unit. Jacks .Jl and J2 are used to connect motorized lens 44 and 4fi to relay K3.
During the day, relay ~l is energized throl~gh capacitor C2, and transistors Q1 and Q2. As dus~ approaches, comparator 60 switches to a high Outpllt state which charges ~ capacitor C3 and energizes relay ~2 through transistors Q3 S and Q4. At the sa~e time, inverter transistor Q6 is turned on which takes its collector terminal to ground. This causes capacitor C2 to start discharging. Relay Kl ~
remain energized until capacitor C2 is discharged. I)ur;llg this time, both relays Kl and K2 are energized, thou~h ~3 is still in the de-energi~ed state. The tirne during which capacitor C2 is discharging is the time allowed for thc low-light camera to warm up. When capacitor C2 finally discharges, relay K1 de-energizes, setting flip flop 74 and energizing relay K3. The night channel ~-ould now be totally ! 15 operative. As may be appreciated by one skilled in the art, the method of sl~itching from the night channel to the day channel is similar to that described above.
Transistor Q5 supplies the power to the light intensifier (block 82) during night channel operation.
Transistor Q5 is turned on when relay ~2 is energized.
Photocell 78 regulates the voltage supplied to the intensi-fier by varying the base current to transistor Q5. The environmental control is provided by fan 53 and heaterJ
resistor R]9 Thermostat 96 controls thc opcration oÇ
heater/resistor R3.
Referring to Figure 5, a perspcctive view of receiver unit l6 is shown. The rece;ver Ullit is ellclose(l in a weather-t;ght housillg 98. Access to the recciver unit is provided by front panel 100, which is secured by 'J7fi~
hinge 101 on one side and a suitab~e locking mechanisnl (partially sho~in a~ 102) on the other side. The receiver circuit board 103 is secured to housing 9~ at each corner - bv screws 104. Power is supplied to the receiver throuc1h connector 118 and cable 119.
Input terminal 105 is used to receive the 10 wires contained in cable 17 (shown in Figure l) connecting passive transmitter unit 18 with receiver unit 16. Con-nector 106 provides cable 17 with access to the receiver unit. Seven switches, generally designated at 107, are used for servicing the transmitter and receiver units.
These switches are functionally identical to the switches contained in the passive transmitter, and include the zoom, focus, iris, on/off, auto/manual, left/right, and up/do~.n functions. Thus, during servicing the monitoring may be operated from the receiver unit. Aux-iliary socket 108 may also be used during servicing, and is directly connected to the 115 ~AC supply which powers the monitoring system.
Switch 109 is also intended to be used during servicing, and acts to cut off the po~er to the monitoTing system.
Output terminal 110 is used to transmit the video control signals to the camera unit 12 (through connector 112 and cable 2Y) and pan-tilt Ul1it 14 (through connector 114 and - cable 115).
Referring to Figure 6, a block diagram of receiver circuit 116 is shown. The OUtp~lt of powcr supl-ly terminal 118 is connected to step down transformer 12n allcl relay power rectifier 12Z. ~he transformcr secondary is connected to rectifier 124. The output of rectifier 1'.4 79~76~j provides an approximate 24 ~DC voltage (~12 ~'nC) to input terminal 105, test switches 107, control circuit 126, pan speed control circuit 127, and control circuit 12c8. Thus, ~ the output of this rectifier provides the ~ower necessary . to operate passive transmitter unit 18. It may be observc~cl that the output o~ lens control circuit 126, indicated at line 130, is di,rectly connected to output terminal 110, ~hereas, the output oE control circuit 128 an~ pan speecl control circui.t 127 are connected through a plura~ity Or ln relays 132 to output terminal 110.
Referring to Figure 7, a circuit diagram of the receiver circuit in Figure 6 is shown. It should he noted that the wiring for the test swi.tches 107 and input termillal 105 is essentially a duplicate of the internal wiring of the passive transmitter unit. The passive transmitter speed potentio~eter is optically coupled to the pan speed control circuit 127 through photomodulator 134. The potentiometer varies the amount of light generated by 134, which in turn varie~ the positive voltage on line 136.
This line 136 is connected through relays 132 to output terminal 110. As indicated in Figure 7, control circuits 126 and 128 are not only similar, but the components in these circuits and their arrangment are identical. The repetitive segment in these c;rcuits, referrecl to hereill-25 ' after as a video control c;rcu;t, will nol~ be describecl.
Referring to Figure 8, a circu;t diagram oE a v;deo control circuit ].38 is shown. The function of this circuit is to selectively appl~ a pos;tive or neg.ltive control voltage to a motor or relay (block 140). Sl~itch -1~--~ ~ 7~6~
142 may eithe~ be one of the test s;itches 107 contained in the receiver unit, or one of the switches contained in the passive transmitter unit. The output of rectifier l24 . provides a positive control voltage at node 144, and a 5 ~ nega~ive control voltage at node 146. When switch 1~2 is in the center or neutral position, the voltage on line 148 will be approximately that of the grountl potentia]. }low-ever, when the switch position is changed so that a positive voltage is applied to line 148, transistor Q8 will be switched on through diode D3. At this time, diode D~ will block current flow, and leave transistor Q9 in an o-ff state. Thus, the positive voltage at node 150 will energize a relay or conduct current through the motor. Simi]arly, when a negative voltage is applied to line 14~, transistor Q9 will be switched on, and therebv energizing the relay or passing current through ~he motor in the reverse direction. One of the significant features of video con-trol circuit 138 is that it permits two control signals to be applied on a single wire. This feature is important in allowing the transmitter unit to be located at a remote distance from the area being monitored by the camera unit.
While it is apparent that the preEerred embodi-ments illustrated and discussed herein are ~cll calc~ tc-1 to fu]fill thc objectives abovc statcd, it will bc a~ rc ciated that thc ~resent ;nvention i5 suscc~til)le to modi-fication, variation, and change without departing from thc scope of the invention, as defined by the following claim~.
BAC~G~OUND OF T~E INVENTION
This is a divisional application of Canadian Application No. 368,196 filed January 9, 1981.
The present invention relates to a remote controlled closed circuit television monitoring system, and in particular to a monitoring system that is adapted to low-light level operation .
A major problem with previous monitoring systems of this type concerns the life o~ the light intensLfier, which is used to enhance or increase the light received at the camera lens during night operation. Due to the sophisti-cated technology involved, the cost of the light intensifier constitutes a significant portion of the total cost of the system. In many monitoring systems, a single camera is employed and the light intensifier is permanently affixed or glued to the face of the camera. Thus, the intensifier will be utilized any time the camera is operational, day or night.
It is also apparent that when the intensifier needs to be replaced, the television camera must also be replaced. In other single camera systems where the intensifier is not directly attached, a motorized mirror or other similar devices must be employed in order to remove the intensifier frorn the path between the lens and camera for day operation.
Another factor affecting the life of the intensi~-ier is the amount of light entering the intensifier. An over-load situation may occur if the ambient light intensity is beyond an acceptahle limit for the light intensifier. 'rhis situation has been controlled previously with neutral density filters and lens iris control, or with manual intensifier gain control.
1 m ~
11'7~76~j Regarciing the transmission of control signals to the television camera, an inherent shortcoming in previous systems concerns the distance range available between the transmitter unit and receiver unit. ln many systems, a power supply is contained in the transmitter unit, and a separate wire is supplied for each control signal to be transmitted to -the receiver. Due to the nurnber and gauge of the wires involved and the sensitivity of the relays in the receiver unit, the distance between the transmitter and receiver is quite limited. This result is counter to the purposes of a remote controlled television monitoring system.
S~MMARY OF TE~E INVENTION
Briefly stated, the present invention consti-tutes an improvement for a remote control apparatus in a television monitoring system having a transmitter unit for providing control signals, a camera unit for providing avideo signal, a receiver unit in association with the transmitter unit and the camera unit, and at least one ac-tuator for controlling the camera unit in response to the control signals.
The improvement comprises a source of d.c. voltage electrical power for the transmitter unit, contained in the receiver unit, and connected to the transmitter unit via a pair of conductors; a single conductor for transmitting two of the control signals from the transmitter unit to the receiver unit; and a video corltrol circuit means, contained in the receiver unit, for selectively utilizing the two control signals, -transmitted alternatively on the single conductor, to energize the actuator.
dm~
3L ~ 7t~7~i Other objects, fea-tures and advan-tages of the present invention will become apparent from the subsequent description and examples, and the appended claims taken in conjunction with the accompanying drawinqs.
BRIFF DFSCRIPTION OF T~IE DRAllINGS
Figure 1 is a perspective view o~ the mon:itorincJ
system according to the present invention, including the camera unit, the pan-tilt unit, the receiver unit, -the passive transmitter unit, and -the monitor uni-t.
Figure 2 is a top elevation view of the dual channel camera unit.
Figure 3 is a block diagram of the channel control circuit contained in the camera unit.
Figure 4 is a circuit diagram of the channel control circuit contained in the camera unit.
Figure 5 is a perspective view of the receiver unit.
Figure 6 is a block diagram of the receiver circuit shown in Figure 5.
~0 Figure 7 is a circuit diagram of the receiver circuit shown in Figure 5.
Figure 8 is a circuit diagram of a video control circuit which comprises a por-tion of the rece:iver circuit.
ms~ ,~
:1*~ 6~
DETAILED DESCRIPTION O~ THF PREFE RED E~IBODIME.~T
Referring to Figure l, a perspective view o~ a television monitoring system 10 according to the present invention is shown. The monitoring system is generally ~- comprised of a dual channel camera unit 12, a pan-tilt unit 14, a receiver un;t 16, a passive transmitter unit 18, and a television monitor unit: 19. The camera unit is mounted on the pan-tilt unit, allowing for the controlled positioning of the camera unit in the horizontal and vertical directions. The operation of the system is con-trolled from the passive transmitter. Control signals are sent from the passive transmitter, through cable 17, to the receiver. The signals are then processed through the various video control circuits in the receiver, and sent to the camera and pan-tilt units. As indicated by the break in cable 17, the passive transmitter is typically located remote from the receiver. According to the present invention, the passive transmitter may be located up to 30,000 feet from the receiver, using number 22 wire for the wires contained in cable 17. The transmitter unit 18 is referred to as "passive" because the transmitter does not contain a separate power supply. The electrical power required by the transmitter is provided by a power supply contained in thc receiver. This power supply also provi~les the electrical power needed to operatc the camera unit.
The video output signal from the camera unit 12 is transmitted by cable 21 to the remote te]evision monitor l9. Typically, the monitor 19 and transmieter 18 are 1 1'7976~i locate(l in the same place so that the person viel~ing the picture on t1le n~onitor screen can also operate the trans-mitter and thus move or adjust the camera unit 12.
- Preferably a lO inch or 12 inch monitor unit manufactured by Audio Tronics~ lnc., Minneapolis, Minnesota is used for the monitor 19, but any equivalent or other conventional unit can be utili~ed.
The front face 20 of the passive transmitter contains a number of operational or video controls. The on/off switch 22 is used to provide electrical power to camera unit 12. This switch as well as the remaining four switches are three position lever switch (nonlocking on both sides). The auto/manual switch 24, pan speed potentio-meter 26, and joystick 28 control the operation of the pan-tilt unit 14. In the automatic mode, the pan-tilt unit sweeps or pans the camera unit horizontally left and right within the boundaries determined by the adjustable limit switches contained in the pan-tilt unit. ln the manual mode, the camera unit is ordinarily stationary. I-lolvever, the position of the camera unit may be altered in the vertical or horizontal direction under the control of joystick 28. The joystick is generally comprised of a two position switch for each direction of movement (left, right, up, down), and is standard in thc art. Pan sl~ecd potentiometer 26 is used to vary the speed of the camera unit in the horizontal direction from 0.0 to 8.0 degress per second. Zoom switch 30, focus sw-itch 32, and ;ris switch 3~ are used o control the operation of the monitori~ed lens in the camera unit. Pan-tilt unit 14 is 37~
of a standard type manuf~ct-lred by Quic~-Set, Inc., Northbrook, Illinois. It is capable of panning from 0 to 340 degrees horizontally, and tilting fro,n 45 degrees ahove to 45 degrees below horizont~l. The pan-tilt unit may be mounted on any suitable structure ~hich will permit the desired camera unit scanning range, such as pole 35.
Referring to Figure 2, a top elevation view of - dual channel camera unit 12 is shown. The camera unit includes two separate television cameras, a day-light camera 36 and a low-light camera 38. Both cameras are manufactured by Panasonic, with the day-light carnera iden-tified as model No. llOOA and the low-light camera i~enti-fied as Model lOOOA. Each camera provides a separate video channel, generally designated as a day channel (day-light lS camera 36) and a night channel (low-light camera 38). T}le day channel is used when the ambient light intensity on faceplate 39 is between 10,000 foot candles (full sunlight) and 1.0 foot candle (daybreak). When the ambient light is reduced to approximately 1.0 foot candles (dusX) the night channel will be utilized. The night channel will typically be operated over a range in light intensity from 1.0 foot candles to 0.00001 foot candles (overcast night).
In addition to low-light camera 38, the night channel also includes light intensifier 40, relay lenscs 42, and motorized lens 44. T}le l;ght intcnsificr is mann-factured by Varo Electron l)eviccs, Inc., Garland, 'le~as and is characterizcd as a 25mm image intens;fier witll il 180K gain. The light intensifier 40 is used to en}lllncc or increase the light received at lens 44. The motorizcd lens 44 is man-lfactured ~y Vicon, Inc., ~'eli Yor~, Ne~ 'or~.
11 ~97~6 It is characterizcd as an l8-144mm zoom lens on a 1 format with a minimum f/stop of 2.0 giving a 25-200mm zoom range on a 2/3 format. The relay lenses 42 co~prise two con-ventional 50mm lenses(f 1.43 and are spaced apart slightly as shown.
- The day channel is comprisel of day-light camera 36 and motorized-lens 46, and is mounted substantially parallel to the n;ght channei components. Motorized lens 46 is identical ~o motorized lens 44 in the night channel.
It should be appreciated that this separation of the day and night channels not only increases the life of the intensifier, but also provides crisper day channel picturc,s.
This is due to the elimination of the light intensifier and relay lens from the day channel.
Circuit board 48 contains the channel control circuit 54 (which is described in more detail with refer-ence to Figures 3 and 4). As indicated from the front face 20 of transmitter 18, there is no provision for manually switching the camera channels. This function is performed automatically by the channel control circuit 54. The cir-cuit board 48 is connected (via a conventional edge connector) to a connector circuit board 49. The connector board 49 brings the video and electrical signals into the circuit board 48 and also relays the video output signal to 1he monitor 19. Jacks/sockets 50 ancl 51 are used to connect , the video si~nal cables 5() and 51 frolll the two tel(~vision cameras 36 and 38 with circuit board 49 ancl in turn Witl the control circuit 54. Plugs/sockets 41 and 43 are ~ISC?~
to connect the electrical power via cal)1es 41 anl 4:i to the two cameras 36 and 38. Jack-socket 45 is usel to connect the vicleo output si~nal from the camera 12 ~via circuit boarcl 49) throu~h cable 21 to the exterll~l Vi(Wi :l t7'~76~
monitor ]9. The connoctor board 43 also has a terminal block 47 on one edge whicll connects the circuit bosrds 48 and 49 to reeeiver 16 v;a socket 37 ancl cable 29.
The light intensifier 40 is conl,ectl3c3 as by p]-lg 33 ancl appropriate wiring to the connector boarcl 49 throu5h tormirlal 47. ~lotorized lenses 44 and 46 are conrl(Jcted to circuit borlr(l 48 by jacks/sockets 25 and 27 and cables 25' and 27'.
The camera ~init 12 also contains a therMostatically controlled 100 watt res-istive-ceramic type heater 58 (mounted in the front of eamera unit 12 under the motorized lenses 44 and 46), and a 115 VAC fan 53 which provides eontinuous air circulation whenever power is supplied to the camera unit.
The heater is controlled by thermostat 96 and is adapted to be automatieally switehed on at 55F and switched off at 65"F.
The heater 58 and fan 53 are connected to eireuit board 49 through terminal block 47.
All of the heretofore mentioned devices contained in the camera unit 12 are modularly mounted in housing 55. The low-light camera 38 is attached to one of the relay lenses 42 as one unit and the light intensifier 40, motorized lens 44 and other relay lens are also attached together as a second unit, and each of these units can be takon out and replaced as a unit, or the separate items can l)e detached in the camera 12 and replaced indiv;dually. Brackets 57 and 59 are attrlclled to the bottom 61 of the housing 55 and llold the low-lir~?lt camera units in place. The light in~ensifier /10 is attached tas hy screws) to ul-right portion of bracket 57, while brac~et 59 is adapted to slide over camera 38 and secure it in place by means of two screws 69. The screws 69 are made of a plastic material, such as Delrin1r, to eliminrlte ground loops which would cause a noisy video sigllrll. Similarly, the day-light camera 36 and motorized lens 46 are attached tor~ether as a unit or individnally. The overhanring portion of bracket 57 a Tre~d~3 llarl;
97~6 is attachc(l nlso by plastic screws 69 to camera 36 and secures this latter two-colnponent unit in place. This nlodul.ll mourl~illg arrangelllerlt, as well as the plug/sockct and jack/socket conllec-tions~ uleaJI.s that all of the comporlerlts may ~JC readily rcmoved S and replaccd without taking dowrl tne camerLI urlit 12 itself.
Ilousing 55 also provides a weather-tight seal which ~rosists the entry of moisture into the unit. A cover member 6S
is adapted to fit over the bottorn meMber 61 and is held tightly in plaee by conventional fasteners 65.
Referring to Figure 3, a block diagram of channel control circuit 54 is shown. This circuit performs two basic functions, channel switching control and light intensifier eontrol. As stated previously, the switehing from one channel to another occurs automatically. This switching is based on a variation in the amb;en~ light intensity, as sensed by photocell 56 mounted on receiver unit 16 ~best shown in Figure 5).
The signal from photoeell 56, as with the other signals sent from the reeeiver to the eamera unit, enter at input terminal 58. The voltage signal from the photocell is compared via comparator 60 with a reference voltage supplied by trans-former and regulator 62. The reference voltage is selected so that the comparator 60 will generate a high output volta~e at dusX and a low output voltage at daybrea~, on line 64. l'hc output from the comparator 60 is connected on two relay a~
ZS timing cireuits. I,ine 64 is directly connecte-l to tl)e low-light camera power relay and time delay circuit 66, an(l indirectly connected througll invertor 68 to day-lig)lt camela power relay and time delay eircuit 70. Circuits 66 and 70 arc used to turn off and on tlle eloctrical power to the two carneras.
Thus, when the output of the comparator sw;tches high at dus~, a relay in circuit 66 will be actuate(1, and l)ower will be supplied to the low-light ealllera. Similar]y, inverter 68 will generate a low OUtpllt to circuit 70 whon the c-mr,lr.ltor outrllt 1179~6t, res~ollses to tl~e comparator output do not occur simul~all-eously. In both circuits 66 and 70, a time delay capacitor is provided to allow the camera being energized to warm up ~or stabilize before the other camera is de-energized. Thus, in the situation above the day-light camera would remain on for approximately 60 seconds after the low-light camera ~as turned on. When the day-light camera is turned ofE, the actuation of the relay in circuit 70 will set the out-put, line 72, of flip flop 74. This will activate a relay in circuit 76 to transfer the motorized lens power and control, as well as video output of the camera unit, to the new channel. In the situation above, the video output would be that of the night channel, and motorized lens 44 would be operational. It should be appreciated that as day-break occurs, the day channel will be supplied with po~er and control in the same manner as described for the night channel.
The second function of channel control circuit 54 is to control the gain of the light intensifier durin~ night channel operation. This control is based upon photocell 78.
This photocell is mounted near the inside surface of face plate 39 of the camera unit 12. The voltage signal from the photocell 78 is connected to light intensifier control cir-cuit 80. This circuit is used to vary the voltage sent ~o the light intensifier control 82 and thereby control the gain.
This intensifier control 82 also acts to provide automatic overload protection of the intensifier. Thus as the arllhient .
-~ ~.7~7~i~
light increases with the approach of daybreak, or a high intensity source of light impinges on the intensifier, the light will not o~erload the intensifier as is possible with manual control.
Referrin~ to Figure 4, a circu;t diagram of the channel control circuit in Figure 3 is shown. Transformer and regulator block 62 is now shown to be comprised of step down trnasformer 86 and regulator 88. Transformer 86 provides t~o 7.5 VAC secondary outputs, and along Wit}l diodes Dl and D2 and capacitor Cl, an approximate 12 VDC
1~ voltage is supplied across lines 90 and 9Z. Regulator 88 is a National Semiconductor LM340T regulator, and it supplies an 8VDC output voltage. This output is connected to two voltage dividers RlR2 and R3R4. These resistors set an upper and lower "trip" point for comparator 60, an LM339 IC manufactured by National Semiconductor. Capacitor C2 provides the time delay in day-light camera power relay and time delay circuit 70, and capacitor C3 provides the time delay for circuit 66. Relay Kl is the power relay for the day-ligllt camera, and relay K2 is the power relay for the low-light camera. Each relay has two sets of con-tacts, the first being used to set or reset flip flop 74 and the second being used to energize or de-energi~e the cameras. Flip flop 74 is an L~555 Timer manufactured by National Semicondllctor. The o~ltpUt of thc flip f~op, line 72, is connec-ted to relay K3. Relay K3 is used to transfer the lens power and control, as well as the ~ideo signal output from the camera unit. Jacks .Jl and J2 are used to connect motorized lens 44 and 4fi to relay K3.
During the day, relay ~l is energized throl~gh capacitor C2, and transistors Q1 and Q2. As dus~ approaches, comparator 60 switches to a high Outpllt state which charges ~ capacitor C3 and energizes relay ~2 through transistors Q3 S and Q4. At the sa~e time, inverter transistor Q6 is turned on which takes its collector terminal to ground. This causes capacitor C2 to start discharging. Relay Kl ~
remain energized until capacitor C2 is discharged. I)ur;llg this time, both relays Kl and K2 are energized, thou~h ~3 is still in the de-energi~ed state. The tirne during which capacitor C2 is discharging is the time allowed for thc low-light camera to warm up. When capacitor C2 finally discharges, relay K1 de-energizes, setting flip flop 74 and energizing relay K3. The night channel ~-ould now be totally ! 15 operative. As may be appreciated by one skilled in the art, the method of sl~itching from the night channel to the day channel is similar to that described above.
Transistor Q5 supplies the power to the light intensifier (block 82) during night channel operation.
Transistor Q5 is turned on when relay ~2 is energized.
Photocell 78 regulates the voltage supplied to the intensi-fier by varying the base current to transistor Q5. The environmental control is provided by fan 53 and heaterJ
resistor R]9 Thermostat 96 controls thc opcration oÇ
heater/resistor R3.
Referring to Figure 5, a perspcctive view of receiver unit l6 is shown. The rece;ver Ullit is ellclose(l in a weather-t;ght housillg 98. Access to the recciver unit is provided by front panel 100, which is secured by 'J7fi~
hinge 101 on one side and a suitab~e locking mechanisnl (partially sho~in a~ 102) on the other side. The receiver circuit board 103 is secured to housing 9~ at each corner - bv screws 104. Power is supplied to the receiver throuc1h connector 118 and cable 119.
Input terminal 105 is used to receive the 10 wires contained in cable 17 (shown in Figure l) connecting passive transmitter unit 18 with receiver unit 16. Con-nector 106 provides cable 17 with access to the receiver unit. Seven switches, generally designated at 107, are used for servicing the transmitter and receiver units.
These switches are functionally identical to the switches contained in the passive transmitter, and include the zoom, focus, iris, on/off, auto/manual, left/right, and up/do~.n functions. Thus, during servicing the monitoring may be operated from the receiver unit. Aux-iliary socket 108 may also be used during servicing, and is directly connected to the 115 ~AC supply which powers the monitoring system.
Switch 109 is also intended to be used during servicing, and acts to cut off the po~er to the monitoTing system.
Output terminal 110 is used to transmit the video control signals to the camera unit 12 (through connector 112 and cable 2Y) and pan-tilt Ul1it 14 (through connector 114 and - cable 115).
Referring to Figure 6, a block diagram of receiver circuit 116 is shown. The OUtp~lt of powcr supl-ly terminal 118 is connected to step down transformer 12n allcl relay power rectifier 12Z. ~he transformcr secondary is connected to rectifier 124. The output of rectifier 1'.4 79~76~j provides an approximate 24 ~DC voltage (~12 ~'nC) to input terminal 105, test switches 107, control circuit 126, pan speed control circuit 127, and control circuit 12c8. Thus, ~ the output of this rectifier provides the ~ower necessary . to operate passive transmitter unit 18. It may be observc~cl that the output o~ lens control circuit 126, indicated at line 130, is di,rectly connected to output terminal 110, ~hereas, the output oE control circuit 128 an~ pan speecl control circui.t 127 are connected through a plura~ity Or ln relays 132 to output terminal 110.
Referring to Figure 7, a circuit diagram of the receiver circuit in Figure 6 is shown. It should he noted that the wiring for the test swi.tches 107 and input termillal 105 is essentially a duplicate of the internal wiring of the passive transmitter unit. The passive transmitter speed potentio~eter is optically coupled to the pan speed control circuit 127 through photomodulator 134. The potentiometer varies the amount of light generated by 134, which in turn varie~ the positive voltage on line 136.
This line 136 is connected through relays 132 to output terminal 110. As indicated in Figure 7, control circuits 126 and 128 are not only similar, but the components in these circuits and their arrangment are identical. The repetitive segment in these c;rcuits, referrecl to hereill-25 ' after as a video control c;rcu;t, will nol~ be describecl.
Referring to Figure 8, a circu;t diagram oE a v;deo control circuit ].38 is shown. The function of this circuit is to selectively appl~ a pos;tive or neg.ltive control voltage to a motor or relay (block 140). Sl~itch -1~--~ ~ 7~6~
142 may eithe~ be one of the test s;itches 107 contained in the receiver unit, or one of the switches contained in the passive transmitter unit. The output of rectifier l24 . provides a positive control voltage at node 144, and a 5 ~ nega~ive control voltage at node 146. When switch 1~2 is in the center or neutral position, the voltage on line 148 will be approximately that of the grountl potentia]. }low-ever, when the switch position is changed so that a positive voltage is applied to line 148, transistor Q8 will be switched on through diode D3. At this time, diode D~ will block current flow, and leave transistor Q9 in an o-ff state. Thus, the positive voltage at node 150 will energize a relay or conduct current through the motor. Simi]arly, when a negative voltage is applied to line 14~, transistor Q9 will be switched on, and therebv energizing the relay or passing current through ~he motor in the reverse direction. One of the significant features of video con-trol circuit 138 is that it permits two control signals to be applied on a single wire. This feature is important in allowing the transmitter unit to be located at a remote distance from the area being monitored by the camera unit.
While it is apparent that the preEerred embodi-ments illustrated and discussed herein are ~cll calc~ tc-1 to fu]fill thc objectives abovc statcd, it will bc a~ rc ciated that thc ~resent ;nvention i5 suscc~til)le to modi-fication, variation, and change without departing from thc scope of the invention, as defined by the following claim~.
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. For a remote control apparatus in a television monitoring system having a transmitter unit for providing control signals, a camera unit for providing a video signal, a receiver unit in association with said transmitter unit and said camera unit, and at least one actuator for controlling said camera unit in response to said control signals, the improvement comprising:
a source of d.c. voltage electrical power for said transmitter unit, contained in said receiver unit, and connected to said transmitter unit via a pair of conductors;
a single conductor for transmitting two of said control signals from said transmitter unit to said receiver unit; and a video control circuit means, contained in said receiver unit, for selectively utilizing said two control signals, transmitted alternatively on said single conductor, to energize said actuator.
a source of d.c. voltage electrical power for said transmitter unit, contained in said receiver unit, and connected to said transmitter unit via a pair of conductors;
a single conductor for transmitting two of said control signals from said transmitter unit to said receiver unit; and a video control circuit means, contained in said receiver unit, for selectively utilizing said two control signals, transmitted alternatively on said single conductor, to energize said actuator.
2. The remote control apparatus according to claim 1, wherein said two control signals are generated from said d.c. voltage electrical power.
3. The remote control apparatus according to claim 2, wherein said d.c. voltage electrical power provides a positive voltage on one of said conductors and a negative voltage on the other of said conductors.
4. The remote control apparatus according to claim 1, wherein said video control circuit means comprises:
a first switching means for transmitting a positive voltage to energize said actuator in one direction;
a second switching means for transmitting a negative voltage to energize said actuator in the reverse direction; and a selective blocking means for alternatively gating on and off said first and second switching means in response to a control signal from said transmitter unit.
a first switching means for transmitting a positive voltage to energize said actuator in one direction;
a second switching means for transmitting a negative voltage to energize said actuator in the reverse direction; and a selective blocking means for alternatively gating on and off said first and second switching means in response to a control signal from said transmitter unit.
5. The remote control apparatus according to claim 4, wherein said actuator is an electric motor.
6. The remote control apparatus according to claim 4, wherein said actuator is a relay.
7. The remote control apparatus according to claim 4, wherein said first and second switching means are transistors.
8. The remote control apparatus according to claim 7, wherein said selective blocking means comprises a diode connected to a base terminal of each of said first and second switching transistors.
9. For a remote control apparatus in a television monitoring system having a transmitter unit for providing control signals, a camera unit for providing a video signal, a receiver unit in association with said transmitter unit and said camera unit, and a plurality of actuators for controlling said camera unit in response to said control signals, the improvement comprising:
a source of electrical power for said transmitter unit, contained in said receiver unit, and connected to said transmitter unit via a pair of conductors;
a single conductor for each of said plurality of actuators for transmitting at least two control signals from said transmitter unit to said receiver unit: and video control circuit means for each of said plurality of actuators, contained in said receiver unit, for selectively utilizing said two control signals, transmitted alternatively on said single conductor, to energize one of said actuators.
a source of electrical power for said transmitter unit, contained in said receiver unit, and connected to said transmitter unit via a pair of conductors;
a single conductor for each of said plurality of actuators for transmitting at least two control signals from said transmitter unit to said receiver unit: and video control circuit means for each of said plurality of actuators, contained in said receiver unit, for selectively utilizing said two control signals, transmitted alternatively on said single conductor, to energize one of said actuators.
10. The remote control apparatus according to claim 9, wherein said source of electrical power provides a d.c.
low voltage signal on said pair of conductors, such that one of said conductors provides a positive voltage and the other of said conductors provides a negative voltage.
low voltage signal on said pair of conductors, such that one of said conductors provides a positive voltage and the other of said conductors provides a negative voltage.
11. The remote control apparatus according to claim 10, wherein said transmitter unit includes a switch for each of said plurality of actuators for generating said two control signals from said positive and negative voltage signals.
12. The remote control apparatus according to claim 1], wherein said switches are connected electrically in parallel to said positive and negative voltage signals.
13. The remote control apparatus according to claim 12, wherein said switches comprise three-position switches.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000441721A CA1179766A (en) | 1980-01-11 | 1983-11-22 | Television monitoring system |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US111,300 | 1980-01-11 | ||
| US06/111,300 US4293876A (en) | 1980-01-11 | 1980-01-11 | Television monitoring system |
| CA000368196A CA1163358A (en) | 1980-01-11 | 1981-01-09 | Television monitoring system |
| CA000441721A CA1179766A (en) | 1980-01-11 | 1983-11-22 | Television monitoring system |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000368196A Division CA1163358A (en) | 1980-01-11 | 1981-01-09 | Television monitoring system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1179766A true CA1179766A (en) | 1984-12-18 |
Family
ID=27166928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000441721A Expired CA1179766A (en) | 1980-01-11 | 1983-11-22 | Television monitoring system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1179766A (en) |
-
1983
- 1983-11-22 CA CA000441721A patent/CA1179766A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4700230A (en) | Modular video control system | |
| US7321120B1 (en) | Motion detector module | |
| US4293876A (en) | Television monitoring system | |
| US4689547A (en) | Multiple location dimming system | |
| US4843461A (en) | Over-door interphone system provided with a night-vision monitoring device | |
| US4745351A (en) | Multiple location dimming system | |
| US5031082A (en) | Remotely controlled security lighting | |
| CA2755805A1 (en) | Occupancy sensing with device clock | |
| JPS6330612B2 (en) | ||
| CA1179766A (en) | Television monitoring system | |
| JPH0357697B2 (en) | ||
| US4881128A (en) | Video camera and recorder system with illumination control features | |
| EP0507349B1 (en) | Control of the photometric area of an image pickup device | |
| US4369467A (en) | Video camera monitoring system | |
| CA1179767A (en) | Television monitoring system | |
| US5962982A (en) | Remote positionable photocell device for use with an exterior landscape lighting assembly | |
| CN205280151U (en) | High voltage isolator vibration state monitoring system | |
| US3887277A (en) | Apparatus for remotely controlling a slide projector | |
| US4542403A (en) | Method of confining the signal level range of a television camera | |
| EP0331647A2 (en) | A modular kitchen with an integrated safety system | |
| EP0455765A1 (en) | Automatic house-circuit control system | |
| GB2076267A (en) | Protective apparatus for tv pick-up tube | |
| CN2166525Y (en) | Remote-control automatic orientation apparatus for antenna of TV | |
| JPS61148976A (en) | Diaphragm controller of television lens | |
| JP3210696B2 (en) | Wireless receiver for remote control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |