JPS61234633A - Communication system for two-dimensional information - Google Patents

Abstract

PURPOSE:To transmit two-dimensional information with a small power consumption by modulating the rays of light having different wavelengths by means of the information of each picture element constituting the two-dimensional information and transmitting the modulated lights through an optical waveguide as wavelength-multiplexed optical signals. CONSTITUTION:A photodiode array 100 is composed of 512X512 photodiodes arranged in a plane corresponding to the picture elements of two-dimensional picture information and converts two-dimensional picture information into electric signals. The array 100 resolves the information into four sheets of picture information at every 4th line and obtains electric signals of 512X128. The electric signals are optically modulated by 512X128 pieces of laser diodes which are arranged in a plane on a heterodyne modulator array 101 and have wavelengths lambda1, 1-lambda128, 512 and sent to an optical fiber 103 after they are multiplexed and combined by a light insertion multiplexing circuit 102. The transmitted signals are demultiplexed by an optical demultiplexing and branching circuit 104 and detected by a heterodyne detector array 105 and then, displayed by means of a light emitting element array 106.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a two-dimensional information communication system, particularly a two-dimensional information communication system for transmitting and exchanging two-dimensional information such as video information. .

(Prior Art and its Problems) In recent years, research has been progressing on broadband communication networks for transmitting and exchanging various broadband high-speed signals, including video signals.

Generally, video information is converted into time-series one-dimensional information by scanning with 525 scanning lines of 1000 i two-dimensional information for one screen of video information on the imaging side, as shown in Figure 1O, and transmitted to a broadband communication network. Send. After scanning one image, the same operation is repeated for the next screen, and by sending out 30 images per second, the movement on the screen appears continuous. The time-series one-dimensional information obtained in this way has a band of, for example, 4 MHz.

The block diagram shown in FIG. 1O shows a broadband communication network for transmitting and exchanging video information as described above.

By scanning each screen 1000 of video information, -1,
The time series-dimensional information of the 4MHz band obtained by PCM
The encoder 1001 converts the signal into a PCM digital signal. If an 8-bit PCM encoder is used as the PCM encoder 1001, an analog signal with a band of 4 MH2 is converted into a digital signal with a bit rate of 64 Mb/S. The digital signal thus obtained is converted into an optical signal by an electrical-to-optical conversion circuit 1002, and then delivered to a broadband exchange via a subscriber line optical fiber 1003.

In the broadband exchange, after the optical signal from the subscriber is converted into an electrical signal (VC) by the optical-to-electrical conversion circuit 1004,
It is connected to an arbitrary outgoing line through a communication path 1005. Here, for example, a time division switch is used for this communication path 1005 to
In order to configure a switch with about 28 lines, 64Mb/
Requires channel memory operating at 5X128=8Gb/S. Therefore, as the communication path 1005, for example, D Black et al.
experimental digi-tal vi
deo switching architecture
e” Internationalswitchin
□ The image information exchanged in this way is converted back into an optical signal by the electro-optical conversion circuit 1006. After that, the signal is sent to the subscriber on the receiving side via the human line optical fiber 1007. At the subscriber on the image receiving side, the moving image information i obtained in this way is converted into an electrical signal by the optical-electrical conversion circuit 1008, and then converted back to an analog signal by the PCM decoder 10 (19) and then used for image reception. The time series-dimensional moving image information thus transmitted and exchanged through the broadband communication network is assembled into two-dimensional information for each screen 1010 and displayed on the image receiver.

However, as mentioned above, since a space division switch is used in the communication path 1005 and it is necessary to switch high-speed signals of 64 Mb/S, when the number of lines reaches several hundred or more, the power consumption of the communication path 1005 is 1. Prices and sizes increase rapidly.

(Object of the Invention) The object of the present invention is to provide a communication method suitable for transmitting and exchanging two-dimensional information such as video information using small devices without consuming much power.

(Structure of the Invention) According to the present invention, there is provided a system for transmitting two-dimensional information through an optical waveguide, in which light having different wavelengths is controlled and adjusted depending on the information of each pixel constituting the two-dimensional information. A two-dimensional information communication signal is obtained, which is characterized in that it is transmitted in the optical waveguide as a wavelength-multiplexed optical signal.

Furthermore, according to the present invention, there is a method for transmitting a plurality of pieces of two-dimensional information through an optical waveguide, in which the information of each pixel constituting each two-dimensional information is digitally encoded, and each digitally encoded pixel signal is used to transmit each piece of information. In addition to modulating and wavelength-multiplexing lights having mutually different wavelengths, the plurality of wavelength-multiplexed optical signals corresponding to each two-dimensional information are time-division multiplexed and transmitted.1-61 (Embodiment) Next, the present invention Examples will be described with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. According to FIG. 1, two-dimensional image information has, for example, 5
The photodiode array 100 has 512 photodiodes arranged in a plane.
It is converted into 12 electrical signals.

The photodiode array 100 converts the 512×512 electrical signals corresponding to each pixel obtained in this way into a second
Heterodyne modulator array 1
01 to reduce the number of modulators required. Therefore, the output side of the photodiode array 100 always has a 512x128
electrical signals can be obtained.

- On the output surface of the ten thousand heterodyne modulator array 101, as shown in FIG.
A total of 512 x 128 laser diodes are arranged in a plane, and the emitted light from these laser diodes is subjected to, for example, FM modulation by a 512 x 128 electric signal output from the photodiode array 100. Here, as shown in FIG. 3 (bl), if, for example, 1.1 μm, l, and 5 μm are selected as λ1,1 and λ128,512, respectively, the wavelength interval λl+1.j between the adjacent wavelengths λ1.j and λ++1.j −λl
, jfd0.4μm/(512xt28)=0.06
Become a person.

The FM heterotine modulator used may be, for example, the one described in "6 Coherent Optical Fiber Transmission Modulation/Demodulation Technology" Saito et al., described in Nippon Telegraph and Telephone Public Corporation Research and Practical Application Report, Vol. 31, No. 12. In addition, the photodiode array 100 and the heterodyne modulator array 1
As the technology for configuring 01, for example, the three-dimensional LSI meeting described in the Proceedings of the 5th Agency of Industrial Science and Technology, Tsukuba General Synobosium, pages 72 to 78 can be used.

The optical signals with wavelengths λ1,1 to λ12B, 512 thus obtained on the output surface of the heterodyne modulator array 101 are multiplexed by the optical add/multiplex circuit 102 and then sent to the optical fiber 103. Ru.

Here, the optical add/multiplex circuit 102 is configured, for example, as shown in FIG. In addition to relaxing the wavelength resolution, the optical loss in the optical insertion circuit array 300 is also reduced. That is, the optical loss in the optical insertion circuit array 300 is 10 J2og 128
=21 dB, and the wavelength selection width Δλ of the 512-wave multiplexing circuit 3010 is Δλ-0.06X128=7.
It becomes 7A.

The wavelength λ1 transmitted through the optical fiber 103 in this way
, 1 to λ128, 512 is applied to the input end of the optical branch/branch circuit 104 at the receiving end. Here, like the optical add/multiplex circuit 102, the optical branch/branch circuit 104 is constituted by an optical branch circuit array 501 consisting of one 512-wave demultiplexer circuit 500 and 512 12.8-wave branch circuits, as shown in FIG. be done. 512 wave branching circuit 5
00 has a wavelength selection width of Δλ=77 people as shown in FIG.
12 optical signals, respectively, with wavelengths λ1+j to λ128. j (j = 1 to 5
12) into 512 groups of wavelength-multiplexed optical signals.

The 512 wavelength-multiplexed optical signals thus obtained are each branched into 128 optical signals by the optical branching circuit array 501, and then sent to the entrance surface of the heterodyne detector array 1050. In the heterodyne/detector array 105, 512 x 128 heterodyne detectors are arranged in a planar manner, and each heterodyne detector detects each pixel from among the wavelength-multiplexed optical signals having wavelengths λx+j to λ1281 jk applied to the input end. An optical signal with a wavelength λ (corresponding to λ) is detected, and an electrical signal of ill:512×128 is obtained at the output surface of the heterodyne detector array 105.

The 512×128 electrical signal thus obtained at the output surface of the heterodyne detector array 105 is shown in FIG.
(al, fbl, (C1, 1 as shown in T mountain
Four image information is displayed every 4 lines every 7120 seconds.

On the other hand, on the output surface Vr- of the light-emitting element array 106, 512×512 light-emitting elements are arranged in a plane corresponding to pixels, and 512×128 light-emitting elements are obtained every 17120 seconds on the output surface Vr- of the heterodie/detector array 106. By electrical signals, (al, (bl, (C1
, (di), two-dimensional image information is displayed by causing the light emitting elements of the corresponding pixels to emit light.

FIG. 6 is a block diagram showing a second embodiment of the present invention. In FIG. 6, the same numbers as in FIG. 1 indicate the same components as in FIG.

According to FIG. 6, the two-dimensional image information is, for example, 512×51
The signal is converted into a 512×512 electrical signal corresponding to each pixel by two photodiode arrays 610 and sent to the input surface of a digital encoder array 611.

Here, as this digital encoder, for example, a ΔM encoder is used to simplify the circuit, and in order to obtain the same image quality as when each pixel information is encoded using 8-pixel PCM encoding,
Image information is captured every 240 seconds.

Here, this ΔM encoder array 611 has 512×512
A ΔM encoder of
512 ΔM signal.

The 512×512 ΔM signals corresponding to each pixel obtained in this way are shown in FIG. 2 as Cal, (bl, (cl,
As shown in (d), the image information is decomposed into four pieces of image information every four lines and output in four parts. Therefore, ΔM encoder array 6
Each signal speed is 240X4=960b/ on the output surface of 11.
A 512×128 electrical signal of s is obtained.

- Laser diodes having wavelengths λl,1 to λ128,512 are arranged in a plane on the output surface of the 10,000-heterodyne modulator array 101, and a ΔM encoder array 611
For example, F'SK modulation is performed using a 512×12B electrical signal output from the 512×12B electrical signal.

The wavelengths λ1,1 to λ128,5 obtained in this way
The twelve optical signals are inserted and multiplexed by an optical add/multiplex circuit 102 and then sent to an optical fiber 103.

The optical demultiplexing/branching circuit 104 receives the wavelengths λ1,1 to λ1 applied to the input end in the same way as in the first embodiment of the present invention shown in FIG.
2g, 512 optical signals with wavelengths λ1+j to λ, respectively.
After demultiplexing into 512 groups of wavelength-multiplexed optical signals of tzs+j (j=1 to 512), each wavelength-multiplexed optical signal is branched into 128 branches and sent to the incident surface of the heterodyne detector array 105.

In the heterodyne detector array 105, 512 x 128 heterodyne detectors are arranged in a plane, and each heterodyne/detector has a wavelength of λ1. A predetermined wavelength λ1 .
The optical signal of j is detected and output as an electrical signal of 5128128 from the output surface.

The input surface of the ΔM decoder array 612 has 51 pixels corresponding to each pixel.
2x512 memories are arranged in a planar layout, Figure 2 (
al, (bl, (c), (dl), t/(2
40X4) every second [512X12 output divided into 4 times]
By storing 8 ΔM signals once, 512x512
Reassemble into a single image information.

The ΔM decoder array 612 is 512×512 for each pixel.
The ΔM decoder converts the 512×512 ΔM signal stored as described above into an analog signal for each pixel and outputs it to the input surface of the light emitting element array 613. On the other hand, the output surface of the light emitting element array 13 has a size of 512×51
Two light emitting elements are arranged in a plane, and two-dimensional image information is displayed by causing the light emitting elements of the respective pixels to emit light in response to a 512 x 512 analog signal obtained on the output surface of the ΔM decoder array 612. .

FIG. 7 is a configuration diagram showing a third embodiment of the present invention. In FIG. 7, the same numbers as in FIG. 6 indicate the same components as in FIG. Also, in Figure 7, 710,7
11,701,702,704゜705.712,71
3 is 610.611 each.

The same components as 101, 102, 104, 105, 612, and 613 are shown.

In FIG. 7, the image information captured by the photodiode array 610 is converted by the ΔM encoder array 611 into 512×128 digital signals, each signal having a bit rate of 240×4=960 b/s. This digital signal is further transmitted to the heterodia modulator array 10.
1 and the optical add/multiplex circuit 102
The signal is converted into a wavelength multiplexed optical signal having wavelengths λ128 and 512 and is applied to the −0 and m inputs of the optical multiplexing circuit 720.

On the other hand, the image information captured by the photodiode array 710 also has wavelengths λ1,1.about.λ128.
The optical multiplexing circuit 7 converts it into a wavelength multiplexed optical signal with 512 gold.
Added to 20 other inputs.

The optical multiplexing circuit 720Fi time-division multiplexes a plurality of wavelength-multiplexed optical signals applied to the input in this way and transmits them to the optical fiber 10.
For example, "Electro-Optical Channel Web Guide Matrix Switch Using Total Innoternal Reflector II7" The Optical Channel Web Guide Matrix Switch 1980. i”uE4
(F,)(,,E-Akkari @” Elect
ro optical channel wavegu
idematrix 5w1tch using to
tal 1internal reflection”
the Topical Meet 11ntegra
ted Guided-WaveOpt, 1980
, TaB2) description (7) 4 waves Wr fJ jfl
It can be realized by y, itte. For example, if we consider the case where 128 wavelength-multiplexed optical signals are time-division multiplexed, the bit rate of the signal carried by light with wavelength λI+j in the optical fiber 103 is 960%, for example → X12
8=123 Kb/s.

In this way, the time-sharing and
The wavelength division multiplexed image information is again separated into a plurality of wavelength division multiplexed optical signals by an optical demultiplexing circuit 721 configured by a waveguide type optical switch similar to the optical multiplexing circuit 720, and each of the signals is input to an optical demultiplexing/branching circuit 104, 704. added to. Optical demultiplexer branch circuit 104 and heterodyne detector array 1
05 is the wavelength λ1,1 to λ128 added to the input,
512 wavelength multiplexed optical signal is converted into a 512×128 electrical signal and sent to the input surface of the ΔM decoder array 612.

The 512×128 digital signal thus obtained is further converted into a 512×51 digital signal by the ΔM decoder array 612.
Image information is displayed by converting the signal into an analog signal of 2 and causing the light emitting elements arranged on the output surface of the light emitting element array 613 to emit light.

Further, the light emitting element array 713 similarly displays image information corresponding to the wavelength multiplexed optical signal obtained at the input of the optical demultiplexing/branching circuit 704.

FIG. 8 is a block diagram showing a fourth embodiment of the present invention.

In FIG. 8, the same numbers as in FIG. 1 indicate the same components as in FIG.

In FIG. 8, the output of the optical multiplex circuit 720 in FIG. 7 is applied to the optical fiber 800. As a result, the wavelengths λ1,1 to λ128,51 are input to the optical demultiplexing/branching circuit 104.
A time-division/5-wavelength multiplexed optical signal is obtained in which light having 2 f and each wavelength λl+j propagates by time-division multiplexing the pixel information of, for example, four moving images.

The optical demultiplexer/branch circuit 104 and the heterodyne detector array 105 convert the time-division 3/wavelength multiplexed optical signal applied to the input into a 512x128 electrical signal and output the communication path memo IJ.
801.

FIG. 9 is a block diagram of the communication path memory 801 shown in FIG. According to FIG. 9, inputs A and B are respectively input to the channel memory 8010 shown in FIG.

512×128 digital signals 900, 901, 902, 903 carrying C, D image information are added.

Call route memo 1J801U addresses 0 and 1 respectively.

=17-2.3 512x128 image memory 9 allocated
04.905.906,907, and is added to the input of the channel memory 801.

H, C, Df 12-bit counter 908 output.

+111X next image memory 904, 905, 906 accordingly
, 907. In this way, image memo 1J
904°905.906.907 K written letter image information A.

H, C, and D are 2 bits x 4 bytes control memory 909
are read out in the order written in the call route memo I.
At the output of J801, 512×128 time division multiplexed digital signals 910, 911, 912°913 are obtained.

Image memo 17904, 905°906 for Chung 9
．． The image information written in 907 is A and C.

An example in which H and D are read in this order is shown. fc914 is a multiplexer i,9 that switches between a write address and a read address according to a control signal applied to an input terminal 915.
16 represents all address decoders.

The 512×128 time-division multiplexed digital signal thus obtained at the output of the channel memory 801 shown in FIG. λ1~λ128,
The signal is converted into a time division/wavelength multiplexed optical signal having a wavelength of 512 f and sent to an optical fiber 802.

In this way, the time division multiplexed image information added to the optical fiber 800 is exchanged with the moving image information exchanger shown in FIG. 8, and is sent out to the optical fiber 802.

In the fc implementation example shown in FIG. 9, an explanation will be given by taking the case of 4 multiplexes as an example.) For example, in the case of 128 multiplexes, the fc is configured into a communication path memo 17801' with a memory of 512 x 128 x 128 = 8.4 Mbit. and the required access time is l/(240X4X1
28)=8 μsec.

(Effects of the Invention) As described above, according to the present invention, it is possible to provide a communication method suitable for transmitting and exchanging two-dimensional information such as video information.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention;
The figure shows how image information is disassembled and assembled in the photodiode array 101 and the light emitting element array 106 shown in FIG.
4 is a diagram showing the configuration of the optical add/multiplex circuit 102 shown in FIG. 1, and FIG. 5 is a diagram showing the configuration of the optical add/multiplex circuit 102 shown in FIG. FIG. 6 is a block diagram showing the second embodiment of the invention, FIG. 7 is a block diagram showing the third embodiment of the invention, and FIG. A block diagram showing a fourth embodiment of the present invention, FIG. 9 is a diagram showing an example of the configuration of the call route memo 1J801 shown in FIG.
FIG. 0 is a diagram showing an example of a video information communication system according to the prior art. In the figure, 100,610,710...)t diode array, 101,701...heterodyne detector array, 102,702...
Original insertion/multiplexing circuit, 104.704... Optical demultiplexing/branching circuit, 105,705'... Heterodyne detector array, 106,613°713... Light emitting element array , 611, 711... 4M modulator array, 612, 712... 2M demodulator array, 720... optical multiplex circuit, 721...
Optical separation circuit 801 . . . Represents communication path memo IJ i, respectively. Plexus 1 time C712,) (b) CC)
(d) Figure 2. J7!7θ Brown S times

Claims (4)

[Claims] (1) A method for transmitting two-dimensional information through an optical waveguide, in which light having different wavelengths is modulated based on the information of each pixel constituting the two-dimensional information, and the information is transmitted through the optical waveguide as a wavelength-multiplexed optical signal. A two-dimensional information communication system characterized by transmission. (2) Information on each pixel constituting two-dimensional information is digitally encoded, and light having different wavelengths is modulated by each digitally encoded pixel signal. The two-dimensional information communication method described in section 1). (3) A method for transmitting a plurality of pieces of two-dimensional information through an optical waveguide, in which the information of each pixel constituting each piece of two-dimensional information is digitally encoded, and each digitally encoded pixel signal is used to transmit each other. A two-dimensional information communication system characterized in that light having different wavelengths is modulated and wavelength-multiplexed, and the plurality of wavelength-multiplexed optical signals corresponding to each two-dimensional information are time-division multiplexed and transmitted. (4) It has a communication path memory in which a plurality of bits are assigned to the same address, and each pixel of the video information screen is allocated to the plurality of bits corresponding to the same address, and the communication path memory has a plurality of Claims (1) to (3) characterized in that the video information is exchanged by controlling either the order in which video information is written or the order in which a plurality of video information is read from the channel memory. 2D information communication method described in ).