Potential-separating optical signal transmitting device
View Patent ↗A potential-separating optical signal transmission device comprises a printed circuit board-based transmitter device with a signal input, a transmission signal conditioning circuit and an optical signal transmitter, a printed circuit board-based receiver device with an optical signal receiver, a received signal processing circuit and a signal output, an optical transmission path between the signal transmitter and the signal receiver, a shield assembly for each transmitter and receiver device, an implementation of the shield assemblies by means of metallic layers in and/or on at least one printed circuit board, and a substantially rigid, transparent transfer rod as an optical transmission path, the ends of said transfer rod being arranged within the respective shield assembly of the transmitter and receiver device in front of the signal transmitter and signal receiver, respectively, and being mechanically held by the at least one printed circuit board.
1 . A potential-separating optical signal transmission apparatus, comprising: a printed circuit board-based transmitter device with a signal input, a transmission signal conditioning circuit, and an optical signal transmitter; a printed circuit board-based receiver device with an optical signal receiver, a received signal processing circuit, and a signal output; an optical transmission path between the optical signal transmitter and the optical signal receiver in form of a substantially rigid, transparent transfer rod; and shield assemblies, including a transmitter shield assembly for the transmitter device and a receiver shield assembly for the receiver device, the shield assemblies being implemented by metallic layers in and/or on at least one printed circuit board, wherein a first end of the transfer rod is arranged shortly in front of or within the transmitter shield assembly in front of the optical signal transmitter, wherein a second end of the transfer rod is arranged shortly in front of or within the receiver shield assembly in front of the optical signal receiver, and wherein the transfer rod is mechanically held by the at least one printed circuit board, wherein the transparent transfer rod ( 10 ) has at least one of the following properties:
made of one of the group consisting of a highly transparent synthetic resin and glass,
length between 10 mm and 100 mm,
diameter 1 mm to 4 mm,
distance of the signal input and output surfaces on a head side to the optical signal transmitter ( 4 ) and signal receiver ( 6 ) between 0.1 mm and 1 mm, and
one of optical preparation and finishing of the signal input and output surfaces on the head side.
2 . The signal transmission apparatus according to claim 1 , wherein the signal transmission apparatus with the transmitter device, the optical transmission path and the receiver device is implemented by combining two printed circuit boards which sit on top of one another, namely a base printed circuit board including a majority of electronic circuit components thereon and a one-piece cap printed circuit board which has a circumferential frame flange for laterally framing the circuit components and a cover wall for covering the circuit components and the transfer rod.
3 . The signal transmission apparatus according to claim 2 , wherein the base printed circuit board and cover wall of the cap printed circuit board are provided with metallic layers arranged parallel to the main planes thereof and the frame flange of the cap printed circuit board is provided with an edge metallization comprising metallic layers.
4 . The signal transmission apparatus according to claim 1 , wherein the transfer rod lies in an alignment recess in a surface of the base printed circuit board.
5 . The signal transmission apparatus according to claim 1 , wherein the optical signal transmitter is designed as an LED.
6 . The signal transmission apparatus according to claim 5 , wherein ageing of the optical signal transmitter can be compensated for by adapting the LED current by means of an ageing compensation circuit based on a reference transmission path with a semiconductor-based light emitter.
7 . The signal transmission apparatus according to claim 6 , wherein the reference transmission path with the semiconductor-based light emitter is a reference LED transmission path.
8 . The signal transmission apparatus according to claim 1 , wherein the optical signal receiver is designed as one of the groups consisting of a CCD, phototransistor, photodiode and photoresistor.
9 . The signal transmission apparatus according to claim 1 , wherein one of the base, frame and cover printed circuit board and the base and cap printed circuit board are mechanically connected to one another in a sandwich structure.
10 . The signal transmission apparatus according to claim 9 , wherein one of the base, frame and cover printed circuit board and the base and cap printed circuit board are mechanically connected to one another by means of one of the group consisting of soldering pins, soldered edge mentalizations, press-fit pins, adhesions, pressings, screwing, riveting and welding.
11 . A potential-separating optical signal transmission apparatus, comprising:
a printed circuit board-based transmitter device with a signal input, a transmission signal conditioning circuit, and an optical signal transmitter; a printed circuit board-based receiver device with an optical signal receiver, a received signal processing circuit, and a signal output; an optical transmission path between the optical signal transmitter and the optical signal receiver in form of a substantially rigid, transparent transfer rod; and
shield assemblies, including a transmitter shield assembly for the transmitter device and a receiver shield assembly for the receiver device, the shield assemblies being implemented by metallic layers in and/or on at least one printed circuit board, wherein a first end of the transfer rod is arranged shortly in front of or within the transmitter shield assembly in front of the optical signal transmitter, wherein a second end of the transfer rod is arranged shortly in front of or within the receiver shield assembly in front of the optical signal receiver, and wherein the transfer rod is mechanically held by the at least one printed circuit board, wherein the signal transmission apparatus with the transmitter device, the optical transmission path and the receiver device is implemented by combining three printed circuit boards which sit on top of one another, namely a base printed circuit board including a majority of electronic circuit components thereon, a frame printed circuit board for laterally framing the circuit components, and a cover printed circuit board for covering the frame printed circuit board, the circuit components and the transfer rod.
12 . The signal transmission apparatus according to claim 11 , wherein the metallic layers of the shield assemblies for the transmitter and receiver device are arranged one of in and on the base, one of the frame and cover printed circuit board and the base and cap printed circuit board in such a manner that around the transmitter and receiver device with their respective electronic circuit components in each case at least one of single-layer and multi-layer is formed, which is penetrated by the transparent transfer rod on a side of one of the transmitter and receiver device.
13 . The signal transmission apparatus according to claim 12 , wherein the multi-layer shielding is a two-layer shielding.
14 . The signal transmission apparatus according to claim 11 , wherein the base printed circuit board and cover printed circuit board are provided with metallic layers arranged parallel to the main planes thereof and the frame printed circuit board is provided with an edge metallization comprising metallic layers.
15 . The signal transmission apparatus according to claim 11 ,
wherein the transparent transfer rod has at least one of the following properties:
made of one of the groups consisting of a highly transparent synthetic resin and glass,
length between 10 mm and 100 mm,
diameter 1 mm to 4 mm,
distance of the signal input and output surfaces on a head side to the optical signal transmitter and signal receiver between 0.1 mm and 1 mm, and
one of optical preparation and finishing of the signal input and output surfaces on the head side.
16 . The signal transmission apparatus according to claim 15 , wherein the transparent transfer rod is made of quartz glass.
17 . The signal transmission apparatus according to claim 15 , wherein the transparent transfer rod has a length of 20 mm.
18 . The signal transmission apparatus according to claim 15 , wherein the transparent transfer rod has a diameter of 2 mm.
19 . The signal transmission apparatus according to claim 15 , wherein the distance of the signal input and output surfaces on the head side to the optical signal transmitter and signal receiver is 0.5 mm.
20 . The signal transmission apparatus according to claim 11 , wherein the transfer rod is arranged in a recess of the frame printed circuit board and is held via projections of the frame printed circuit board by a press fit.