JPS628626A - Optical data transmission system - Google Patents

Abstract

PURPOSE:To obtain an inexpensive parallel data optical transmission system with excellent transmission capacity and mounting density by using a multi-core plastic fiber comprising core wires and plural fibers. CONSTITUTION:8-bit data sent from an 8-bit microcomputer IC1 appears on an 8-bit parallel data bus 2 as a TTL level binary signal and an 8-system LED drive IC3 of a TTL input drives 8 LEDs 4 converting an electric signal of the data bus into an optical signal. The LEDs are blinked and the information is made incident on the 8 fibers 9 of the multi-core plastic fiber 5 via a coupling section 20. The incident light passes through the fiber and reaches 8 PN photodiodes converting the optical signal into an electric signal via the coupling section 20 again. A very small optical current generated by the PN photodiodes is outputted as 8-bit TTL data by an IC7 having 8 systems of amplifying and waveform shaping functions.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is realized by combining a light emitting element and a light receiving element and using a plastic fiber for optical data transmission (hereinafter referred to as plastic fiber) as a transmission path. Regarding optical data transmission, in particular optical data transmission methods using multicore plastic fibers used for combination data links, in-vehicle optical transmission, and parallel data transmission used in machine control systems. .

[Conventional technology]

Conventionally, the following two techniques have generally been used to implement parallel data transmission in optical fiber data transmission.

In a one-channel data transmission system in which data is received by the PN photodiode 6 and received by the amplification/waveform shaping IC, it is necessary to prepare a number of transmission systems equal to the number of parallel data bits.

) As shown in Figure 5, there are 8 pins on the input/output boat) f
-1 The signal from the Hass 2 is converted into a serial signal by the parallel/serial data converter C18, and the LED, [LED4ffi is driven by the dynamic ICl3, and the signal is received by the PN photodiode 6 via the plastic fiber 16, which is amplified and waveform shaping IC.
17t- Serial/parallel data conversion via ICI
9 to make a parallel signal and send it to data bus 2, use l.
A transmission system of channels alone can enable parallel data transmission.

[Problem that the invention seeks to solve]

The above-mentioned conventional technologies each have the following drawbacks: (1) The method shown in Figure 4 requires multiple transmitter/receiver modules and plastic fibers, which increases cost and reduces packaging density. is significantly inferior.

(2) The method shown in Figure 5 converts parallel data into serial
Since the number of parallel data is large, the transmission capacity of the transmission system is limited by the transmission speed of the serial-to-parallel conversion device of the input/output board, so the transmission capacity is inferior, and the optical system element cannot take full advantage of its functions.

Also, the conversion device is difficult to design and therefore expensive, similar to the method of FIG.

[Means for solving problems]

The plastic fiber optical data transmission system of the present invention uses a multicore plastic fiber consisting of a core wire and a plurality of fibers.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a system diagram of an embodiment in which the present invention is applied as a combination data link.

The 8-bit data sent from the 8-bit microcontroller ICI is transferred to the TT on the 8-bit parallel data bus 2.
It appears as an L level binary signal. The TTL input 8-system LED driving IC 3 has the role of driving 8 LEDs 4 for converting electrical signals of the data bus into optical signals. Each LED corresponds to data information on the data bus.
blinks, and the information is input into the eight fibers 9 of the multicore plastic fiber 5 through the coupling portion 20t. 8 for converting the optical signal into an electrical signal by passing the incident light through the ifi fiber and then passing through the coupling section 20 again.
PN photodiodes are reached.

The minute photocurrent generated in the PN photodiode is processed by eight ICs with amplification and waveform shaping functions.
It is output as bit TTL data and becomes a reception signal for a separate 8-bit microcomputer IC via a data bus.

Next, FIG. 2 shows a longitudinal cross-sectional view of the multicore plastic fiber according to the present invention. Eight fibers 9 are arranged at equal intervals around a core wire 8 made of any resin. Then, 10" of dummy fibers are provided to facilitate connection with a portion of the connector shown in FIG.

By making the dummy fiber 10 using colored resin, it can be distinguished from other fibers. Of course,
The existence of the dummy fiber 10 may be revealed by making it different in shape from other fibers or by devising the arrangement of the nine 7 tabers. The coating IO is made of black resin and serves to secure the fiber position and prevent external damage. Note that such multicore plastic fibers can be manufactured using conventional manufacturing methods.

Further, FIG. 3 shows an example of a connector constituting the coupling portion. The female connector 12 shown in FIG. 3(a) has a structure in which a part of the connector and an optical transmitting/receiving case are integrated, and is made of black resin or the like. Similarly to the female connector, the male connector 13 shown in FIG. 3(b) is also made of black resin or the like. In actual use, the relative position between the plastic 7-taper and the male connector is determined by aligning the alignment notch 14 provided at the tip with the aforementioned dummy fiber. Further, since the relative positions of the male connector and the female connector are determined by the positioning groove 21 and the positioning protrusion 22, it is possible to ensure the correspondence of each bit between input and output.

As described above, the 8-system MED drive 1C and the 8-system ICti having amplification and waveform shaping functions can be easily integrated into one chip. Also, 8 LEDs and PN
Similarly, for the photodiode, it is better to correct the optical path between the plastic fiber and the transparent resin mold shape used when enclosing the pellet with a distorted lens. It is practically possible to fabricate it into an l chip as a photodiode.

By using the above method, it is possible to downsize the system without sacrificing transmission capacity.

〔Effect of the invention〕

As explained above, the present invention makes it possible to realize a low-cost parallel data optical transmission system that has excellent transmission capacity and packaging tightness by providing a plastic fiber with a new structure. It is.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an optical data link system realized by an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a multi-core plastic 7-eye bar, and FIGS. Diagram of the connector used in the illustrated embodiment, No. 4
．． 5 are diagrams of conventional optical data link systems. 1...8-bit microcontroller IC, 2...
...8-bit data bus, 3...8 systems L
ED drive IC14...LED, 5...
Multicore plastic fiber%6...PN photodiode, 7...8 IC with amplification and waveform shaping functions, 8...core, 9...・
...Fiber, 10...Positioning dummy fiber, 11...Coating, 12...Female connector, 13...Male connector, 14
......Positioning increments, 15...LED driving IC116...Conventional plastic fiber, 17...IC containing amplification and waveform shaping functions%1B・...: Parallel/serial data conversion IC, 19... Serial/parallel data conversion IC, 20... Connection section, 21...
Positioning groove, 22...Positioning convex portion.

Claims (1)

[Claims] An optical data transmission system characterized by the use of multi-core plastic fibers, in which multiple plastic fibers are arranged around a core wire made of any resin.