JP2006020242A - Transmission equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide transmission equipment capable of suppress unnecessary radiation with an inexpensive structure. <P>SOLUTION: Transmission equipment 10 includes an optical fiber 11, a light source 13 for generating light in response to a low-speed, a phosphor 12 excited by light L2 from the above light source 13, so as to emit fluorescence L3 having a wavelength λ3 different from the wavelength λ1 of an optical signal L1 from the optical fiber, an optical filter 14 for attenuating both the wavelength λ2 of the light L2 from the light source 13 and the wavelength λ3 of the fluorescence L3 of the phospher 12 and for selectively transmitting the wavelength λ1 of the optical signal L1, and a light receiving element 15 for receiving the optical signal L1. In the above transmission equipment 10, the optical fiber 11, the phosphor 12, the optical filter 14 and the light receiving element 15 are disposed on an identical optical path, and the light L2 from the light source 13 is incident on the phosphor 12 in the direction intersecting with the above optical path. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission apparatus that transmits information using an optical fiber.

  Conventionally, electrical signals using coaxial cables have been mainly used for transmission of video signals, etc. However, due to recent digitalization and higher definition, transmission of electrical signals greatly limits the transmission distance. It has become.

On the other hand, with the increase in size and thickness of the display device, the necessity for installing the display device and a device such as a video recording / reproducing device apart from each other has increased.
Large display devices often use digital signals for signal input, and the DVI (Digital Visual Interface) method or HDMI (High Definition Multimedia Interface) method has been established as a transmission standard for many devices. (For example, refer to Patent Document 1).

However, the DVI system or the HDMI system has a problem that a practical transmission distance is as short as several meters.
Furthermore, since the increase in transmission speed leads to an increase in unnecessary radiation, there is a problem that it becomes difficult to take measures against unnecessary radiation of equipment.

Therefore, several countermeasures have been proposed for these problems.
First, as a countermeasure for increasing the transmission distance, for example, a device has been proposed that electrically corrects, shapes a waveform deteriorated by long-distance transmission, and restores the original waveform.
Further, as a countermeasure against both an increase in transmission distance and an increase in unnecessary radiation, for example, a method using an optical fiber has been proposed.
JP 2003-309824 A

When the above-described device that electrically corrects and restores the original waveform is used, the transmission distance is improved.
However, since a configuration for reshaping the waveform and restoring the original waveform is required, there is a problem in that additional costs arise.
Moreover, since no solution is shown for measures against the increase in unnecessary radiation, increasing the length of the cable in order to increase the transmission distance causes an increase in unnecessary radiation.

On the other hand, when an optical fiber is used, an optical transceiver capable of transmitting and receiving is necessary to realize bidirectional transmission. This is because in the DVI system and the HDMI system, it is necessary not only to transmit a video signal but also to transmit a control signal bidirectionally between the display device side and the transmission device side.
And as a structure which transmits / receives using an optical fiber, the system which isolate | separates transmission / reception with two cores, and the system which performs transmission / reception with one core can be considered.

However, the method of separating transmission and reception with two cores is simple in optical configuration, but not only requires two pairs of expensive optical connectors, but also requires two optical fibers. It becomes expensive.
In addition, the method of performing transmission / reception with one core reduces the cost of the transmission line, but complicates the optical configuration.
Therefore, any system cannot avoid an increase in cost.

  In order to solve the above-described problems, in the present invention, a low-speed control signal is transmitted from a display device to a device such as a VTR by using only one optical fiber on the display device side using the DVI method or the HDMI method. Thus, it is possible to provide a transmission device that can be configured at low cost and can suppress unnecessary radiation.

  The transmission device of the present invention transmits information using an optical fiber, and includes an optical fiber, a light source that generates light in response to a low-speed input signal, and light from the optical fiber that is excited by light from the light source. A phosphor that emits fluorescence having a wavelength different from the wavelength of the signal, and an optical filter that attenuates both the wavelength of the light from the light source and the fluorescence of the phosphor and selectively transmits the wavelength of the optical signal. A light receiving element that receives an optical signal from the optical fiber, and the optical fiber, the phosphor, the optical filter, and the light receiving element are arranged on the same optical path, and light from the light source enters the phosphor from the direction intersecting the optical path. It is input.

According to the configuration of the transmission device of the present invention described above, since the phosphor emits fluorescence having a wavelength different from the wavelength of the optical signal from the optical fiber, that is, the received optical signal, if the fluorescence from the phosphor is transmitted from the optical fiber, transmission is performed. And reception can be performed with light of different wavelengths. This makes it possible to transmit and receive information together with a single-core optical fiber, and the optical connector and optical fiber are halved compared to the two-core separation system.
In addition, since the optical filter attenuates both the wavelength of light from the light source and the fluorescence wavelength of the phosphor and selectively transmits the wavelength of the optical signal, the received optical signal and the transmitted optical signal are transmitted by the optical filter. (Fluorescence) can be separated. Thereby, the alignment of the part which isolate | separates transmission and reception becomes unnecessary.
Further, by transmitting and receiving information using an optical fiber, it is possible to suppress generation of unnecessary radiation even when information is transmitted at high speed.

According to the present invention described above, by using an optical fiber, generation of unnecessary radiation can be suppressed even when information is transmitted at high speed.
Moreover, since the optical connector and the optical fiber are halved compared to the two-core separation method, the cost of the transmission device can be reduced. In addition, it has a simple configuration in which the optical fiber, the phosphor, the optical filter, and the light receiving element are arranged on the same optical path. As with the core separation method, only one axis is required. Thereby, manufacture is easy and manufacturing cost can also be reduced.
Furthermore, since there are few parts that require machining accuracy, the part cost can be reduced.

Therefore, according to the present invention, a product with a low price can be provided.
Further, since the structure of the transmission device is simple, the device can be reduced in size.

FIG. 1 shows an optical configuration diagram of a transmission apparatus as an embodiment of the present invention.
The transmission device 10 includes an optical fiber 11, a phosphor 12, an excitation light source 13, an optical filter 14, and a light receiving element 15.

The excitation light source 13 generates excitation light L2 (wavelength λ2) for exciting the phosphor 12 according to a low-speed input signal.
The phosphor 12 is excited by the excitation light L2 from the excitation light source 13, and generates fluorescence L3 (wavelength λ3) corresponding to a low-speed input signal.
The light receiving element 15 receives and detects the optical signal L1 (wavelength λ1) from the optical fiber 11.
The optical filter 14 prevents the fluorescence L3 generated by the phosphor 12 from entering the light receiving element 15.
An optical fiber 11, a phosphor 12, an optical filter 14, and a light receiving element 15 are disposed on the same optical path, and an excitation light source 13 is disposed so as to excite the phosphor 12 from a direction intersecting the optical path. .

As long as the order does not change, these components are arbitrary in size and interval.
However, if the distance from the optical fiber 11 to the light receiving element 15 is increased, a larger light receiving area is required, and the high speed operation necessary for receiving the DVI or HDMI signal cannot be performed. It is necessary to appropriately design the light receiving area and distance according to the operation speed.

Information can be received by detecting the light signal L1 received through the optical fiber 11 by the light receiving element 15.
Further, when the fluorescence L3 generated in the phosphor 12 enters the optical fiber 11, information can be transmitted through the optical fiber 11.

FIG. 2 shows an optical configuration diagram of a transmission apparatus as another embodiment of the present invention.
In this form of transmission device 20, a lens 16 that condenses the optical signal L <b> 1 from the optical fiber 11 on the light receiving element 15 is disposed between the optical filter 14 and the light receiving element 15. Since other configurations are the same as those of the transmission apparatus 10 of the form shown in FIG. 1, the same reference numerals are given and redundant description is omitted.
In the present embodiment, since the optical signal L1 from the optical fiber 11 is efficiently condensed on the light receiving element 15 by the lens 16, it is useful for improving the receiving sensitivity or the receiving speed.
However, when the lens 16 is used, it is necessary to accurately position and assemble the optical axis centers of the optical fiber 11, the lens 16, and the light receiving element 15.

The lens 16 may be between the optical filter 14 and the phosphor 12 or between the optical fiber 11 and the phosphor 12.
Further, the phosphor 12 and the optical filter 14 may have the same function as the lens 16.

Further, the optical filter 14 may be integrally formed on the light receiving element 15 with respect to the configuration of each of the embodiments described above.
In addition to this configuration, a lens 16 that condenses the optical signal L1 from the optical fiber 11 on the light receiving element 15 is further provided between the phosphor 12 and the light receiving element 15 in which the optical filter 14 is integrally formed. A configuration in which the lens 16 is provided between the optical fiber 11 and the phosphor 12, or a configuration in which the phosphor 12 has a lens function of condensing the optical signal L 1 from the optical fiber 11 onto the light receiving element 15. It is also possible.

In the transmission apparatuses 10 and 20 of the above-described embodiments, for example, an electric circuit is configured as shown in a block diagram in FIG.
As shown in FIG. 3, a low-speed input signal S1 is input to the excitation light source drive circuit 21, and the excitation light source 13 performs blinking according to the input signal S1 by the drive circuit 21.
On the other hand, the optical signal L1 from the optical fiber 11 is input to the light receiving element 15 and converted into an electrical signal. The electrical signal converted by the light receiving element 15 is amplified by the reception signal amplification circuit 22 and output as a high-speed output signal S2.

FIG. 4 shows the relationship between the frequency of the received optical signal L1 and the frequency of the excitation input signal S1.
The input signal S1 is an extremely narrow signal having a low frequency band like the excitation input signal band 31 shown in FIG.
On the other hand, the band of the received optical signal L1 has a wide and high frequency band, such as the received light signal band 32 shown in FIG. 4, and is higher than the excitation input signal band 31.

  The excitation light source drive circuit 21 and the reception signal amplification circuit 22 may be built in the transmission apparatuses 10 and 20 or may be outside the transmission apparatuses 10 and 20.

  Next, the wavelength dependence relationship of each component in the transmission apparatuses 10 and 20 according to the above-described embodiments will be described.

In the transmission apparatuses 10 and 20 of the above-described embodiments, since transmission and reception are performed in the same apparatus, it is necessary to make the wavelengths on the transmission side and the reception side different.
The optical filter 14 has a sufficiently high transmittance with respect to the wavelength λ1 of the received optical signal L1 from the optical fiber 11.
Further, the optical filter 14 is required to have a characteristic that sufficiently absorbs the wavelength λ2 of the excitation light L2 from the excitation light source 13 and the wavelength λ3 of the fluorescence L3 generated from the phosphor 12.
Furthermore, since the energy of light is inversely proportional to the wavelength, the fluorescent material generally emits light having a wavelength that is somewhat longer than the absorbed wavelength. Thereby, the emission wavelength λ3 of the phosphor 12 becomes longer than the wavelength λ2 of the excitation light L2 from the excitation light source 13.

Here, FIG. 5 shows one form of the wavelength dependency relationship of each component that satisfies these conditions.
As shown in FIG. 5, the wavelength λ <b> 1 of the received light signal L <b> 1 is within the transmission band 35 of the optical filter 14.
Further, the wavelength λ2 of the excitation light L2 <the emission wavelength λ3 of the phosphor 12 <the transmission band 35 of the optical filter 14.
Accordingly, the emission wavelength λ3 of the phosphor 12 is smaller than the wavelength λ1 of the received light signal, and the transmission wavelength λ3 and the reception wavelength λ1 are different.

  Since the wavelength λ2 of the excitation light L2 and the emission wavelength λ3 of the phosphor 12 do not have to fall within the transmission band 35 of the optical filter 14, the emission wavelength of the phosphor 12 is not limited to the wavelength dependence shown in FIG. λ3 may be longer than the transmission band 35 of the optical filter 14, and both the wavelength λ2 of the excitation light L2 and the emission wavelength λ3 of the phosphor 12 are longer than the transmission band 35 of the optical filter 14. There may be.

  Further, the wavelength λ1 of the received light signal L1 and the emission wavelength λ3 of the phosphor 12 need to be wavelengths with high transmittance of the optical fiber 11, but the wavelength λ2 of the excitation light L2 is a transmission band of the optical fiber 11 (not shown). )).

According to the transmission apparatuses 10 and 20 of the above-described embodiments, the wavelength λ3 of the fluorescence L3 of the phosphor 12 that transmits information is different from the wavelength λ1 of the received optical signal L1 that receives information. Transmission and reception can be performed using only a single optical fiber 11.
Further, since the optical filter 14 attenuates the wavelength λ3 of the fluorescence L3 of the phosphor 12 and selectively transmits the wavelength λ1 of the received light signal L1, the optical filter 14 causes the received light signal L1 and the transmitted light signal L3 to be transmitted. Can be separated. Thereby, the alignment of the part which isolate | separates transmission and reception becomes unnecessary.
Further, by performing transmission and reception using the optical fiber 11, it is possible to suppress the occurrence of unnecessary radiation even when information is transmitted at high speed.

Moreover, since it is the structure which performs transmission and reception with only the single-core optical fiber 11, the cost of the transmission apparatuses 10 and 20 can be reduced because the optical connector and the optical fiber are halved compared to the two-core separation method. .
In addition, the optical fiber 11, the phosphor 12, the optical filter 14, and the light receiving element 15 have a simple configuration in which they are arranged on one axis, and the transmission and reception are performed with a single core, but the optical portion is aligned. However, only one axis is required as in the two-core separation method. Thereby, manufacture is easy and manufacturing cost can also be reduced.
Furthermore, since there are few parts that require machining accuracy, the part cost can be reduced.

  Therefore, according to the transmission apparatuses 10 and 20 of the above-described embodiments, it is possible to provide a product with a low price.

  Further, since the structures of the transmission devices 10 and 20 are simple, the devices 10 and 20 can be downsized.

Note that in a display device adopting the DVI method or the HDMI method, a transmission signal from the display device side is low speed.
For this reason, when the transmission devices 10 and 20 of the above-described embodiment are applied to transmission / reception of control signals between a display device adopting the DVI method or the HDMI method and a transmission device, the excitation light L2 by the low-speed input signal S1. Fluorescence L3 emitted from the phosphor 12 that emits light at a low speed is used for transmission of a control signal from the display device to the transmission device, and a high-speed received light signal L1 is used for transmission of the control signal from the transmission device to the display device. Use it.

  The present invention is not limited to the above-described embodiment, and various other configurations can be taken without departing from the gist of the present invention.

It is an optical block diagram of the transmission apparatus of one embodiment of this invention. It is an optical block diagram of the transmission apparatus of other embodiment of this invention. FIG. 3 is a block diagram showing a configuration of an electric circuit in the transmission device of FIG. 1 or FIG. 2. It is a figure which shows the relationship of the frequency of the optical signal of FIG. 3, and an input signal. It is a figure which shows one form of the wavelength dependence relationship of each component in the transmission apparatus of FIG. 1 or FIG.

Explanation of symbols

  10, 20 Transmission device, 11 Optical fiber, 12 Phosphor, 13 Excitation light source, 14 Optical filter, 15 Light receiving element, 16 Lens, 21 Excitation light source drive circuit, 22 Received signal amplification circuit, 35 Transmission band of optical filter

Claims (10)

A transmission device for transmitting information using an optical fiber,
The optical fiber;
A light source that generates light in response to a slow input signal;
A phosphor that is excited by the light from the light source and emits fluorescence having a wavelength different from the wavelength of the optical signal from the optical fiber;
An optical filter that attenuates both the wavelength of the light from the light source and the wavelength of the fluorescence of the phosphor and selectively transmits the wavelength of the optical signal;
A light receiving element for receiving an optical signal from the optical fiber,
The optical fiber, the phosphor, the optical filter, and the light receiving element are disposed on the same optical path, and the light from the light source is input to the phosphor from a direction intersecting the optical path. Transmission equipment.   The transmission device according to claim 1, wherein a lens for condensing the optical signal from the optical fiber on the light receiving element is provided between the optical filter and the light receiving element.   The transmission device according to claim 1, wherein a lens for condensing the optical signal from the optical fiber on the light receiving element is provided between the phosphor and the optical filter.   The transmission device according to claim 1, wherein a lens for condensing the optical signal from the optical fiber onto the light receiving element is provided between the optical fiber and the phosphor.   The transmission apparatus according to claim 1, wherein the phosphor has a lens function of condensing the optical signal from the optical fiber onto the light receiving element.   The transmission device according to claim 1, wherein the optical filter has a lens function of condensing the optical signal from the optical fiber onto the light receiving element.   The transmission apparatus according to claim 1, wherein the optical filter is integrally formed on the light receiving element.   The lens for condensing the optical signal from the optical fiber to the light receiving element is provided between the phosphor and the light receiving element in which the optical filter is integrally formed. 8. The transmission device according to 7.   The transmission device according to claim 7, wherein a lens for condensing the optical signal from the optical fiber on the light receiving element is provided between the optical fiber and the phosphor. The transmission device according to claim 7, wherein the phosphor has a lens function of condensing the optical signal from the optical fiber onto the light receiving element.

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