HDMI signal extension device

Abstract

The present invention proposes an HDMI signal extension device, comprising a transmitter and a receiver, wherein the transmitter comprises: a first HDMI interface, a first RJ45 interface, a first network transformer, a signal amplification circuit, a power interface, a first voltage circuit, a second voltage circuit, a third voltage circuit and a first filtering and coupling circuit; the receiver comprises a second HDMI interface, a second RJ45 interface, a second network transformer, a comparator circuit, a voltage stabilizing circuit and a second filtering and coupling circuit. The present invention boosts the audio and video signals and the digital control signals to different voltages in the transmitter part and then couples them, and arranges a comparator circuit in the receiver part to effectively separate the digital control signal, which can reduce the interference between the audio and video signals and the digital control signals transmitted by the same cable, effectively increase the transmission distance, and realize the longer-distance transmission of the HDMI signal.

Description

Technical Field

[0001] The invention relates to the technical field of audio and video signal transmission, in particular to an HDMI signal extension device. Background Art

[0002] HDMI (High Definition Multimedia Interface) is a digital video / audio interface technology that meets the standards of the high-definition era and can be used in set-top boxes, DVD players, personal computers and televisions. HDMI can transmit audio and video signals at the same time, and can transmit uncompressed high-definition video and multi-channel audio data with high quality, with a maximum data transmission speed of 5Gbps. In order to achieve long-distance transmission of HDMI signals, network cables are generally used as the transmission medium.

[0003] The existing solutions for transmitting HDMI signals using a single network cable are to directly couple the audio and video signals with the digital control signals and transmit them through the network cable. Due to the interference between the audio and video signals and the digital control signals during the coupled transmission, the transmission distance of the existing technical solutions is only 30 to 60 meters, making it difficult to achieve signal transmission over longer distances. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes an HDMI signal extension device, wherein the transmitter part thereof boosts the audio and video signals and the digital control signals to different voltages and then couples them, and the receiver part thereof is provided with a comparator circuit to effectively separate the digital control signal, thereby realizing longer distance transmission of the HDMI signal.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention provides an HDMI signal extension device, comprising a transmitter and a receiver, wherein the transmitter comprises:

[0007] A first HDMI interface, used for receiving an HDMI signal from a host;

[0008] A first RJ45 interface, used for connecting to the receiver;

[0009] A first network transformer, coupled to the audio and video signal pins of the first HDMI interface, for isolating and voltage amplifying the transmitted audio and video signals;

[0010] a signal amplifying circuit, coupled to the digital control signal pin of the first HDMI interface, and configured to amplify the voltage of the transmitted digital control signal;

[0011] Power interface, used to connect an external DC power supply;

[0012] A first voltage circuit is coupled to the first network transformer and the power interface respectively, and is used to provide a first reference voltage to the first network transformer so as to increase the voltage amplitude of the audio and video signal to the first reference voltage;

[0013] A second voltage circuit is coupled to the signal amplifying circuit and the power interface respectively, and is used to provide a second reference voltage to the signal amplifying circuit so as to increase the voltage amplitude of the digital control signal to the second reference voltage;

[0014] A third voltage circuit, coupled to the power interface, for boosting the external DC power voltage to a third reference voltage to form a power signal;

[0015] The first filtering and coupling circuit is coupled to the first network transformer, the signal amplifying circuit, the third voltage circuit and the first RJ45 interface respectively, and is used to couple the digital control signal and the power supply signal to the audio and video signal for transmission.

[0016] Furthermore, the receiver comprises:

[0017] A second HDMI interface, used to send HDMI signals to a display terminal;

[0018] A second RJ45 interface, used for connecting to the transmitter;

[0019] a second network transformer coupled to the audio and video signal pins of the second HDMI interface, and used to isolate the transmitted audio and video signals;

[0020] a comparator circuit coupled to the digital control signal pin of the second HDMI interface, and configured to extract the transmitted digital control signal;

[0021] a voltage stabilizing circuit, coupled to the comparator circuit, and configured to provide power to the comparator circuit;

[0022] The second filtering and coupling circuit is coupled to the second network transformer, the comparator circuit, the voltage stabilizing circuit and the second RJ45 interface respectively, and is used to separate the digital control signal and the power supply signal coupled to the audio and video signal.

[0023] As an improvement, the transmitter further includes:

[0024] A first control signal interface, used for receiving an external control signal;

[0025] The first microcontroller is coupled to the first control signal interface and the signal amplifying circuit respectively, and is used for converting the received external control signal into a serial control signal.

[0026] As an improvement, the transmitter further includes:

[0027] The transmitting end HDMI interface chip is coupled to the first HDMI interface and the first network transformer respectively, and is used to enhance the audio and video signals.

[0028] As an improvement, the receiver further includes:

[0029] A second control signal interface, used for receiving an external control signal;

[0030] a second microcontroller, coupled to the second control signal interface, and configured to convert a received external control signal into a serial control signal for transmission;

[0031] The receiving end HDMI interface chip is respectively coupled to the second HDMI interface, the second network transformer, the comparator circuit and the second microcontroller, and is used to integrate audio and video signals, digital control signals and serial control signals, and transmit them to the second HDMI interface.

[0032] As an improvement, the amplitude of the first reference voltage differs from that of the second reference voltage by 30%.

[0033] As an improvement, the first reference voltage is 3.3V, the second reference voltage is 5V, and the third reference voltage is 12V.

[0034] Beneficial effects of the present invention:

[0035] The present invention boosts the audio and video signals and the digital control signals to different voltages in the transmitter part and then couples them, and sets a comparator circuit in the receiver part to effectively separate the digital control signal, which can reduce the interference between the audio and video signals and the digital control signals transmitted by the same cable, effectively increase the transmission distance, and realize the longer-distance transmission of HDMI signals. When CAT5E or CAT6 cables are used for transmission, the transmission distance can reach 100 to 150 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of an HDMI signal extension device provided by the present invention;

[0037] Figure 2 The schematic diagram of the peripheral circuit of the network transformer at the transmitting end of the present invention;

[0038] Figure 3 It is a schematic diagram of the structure of the main components of the network transformer at the sending end of the present invention;

[0039] Figure 4 The schematic diagram of the signal amplification circuit at the transmitting end of the present invention;

[0040] Figure 5 This is a schematic diagram of the transmitting end filtering and coupling circuit of the present invention. DETAILED DESCRIPTION

[0041] In order to more clearly and completely illustrate the technical solution of the present invention, the present invention is further described below in conjunction with the accompanying drawings.

[0042] Please refer to Figure 1 The present invention provides an HDMI signal extension device, comprising a transmitter 100 and a receiver 200. The transmitter 100 comprises an HDMI interface 101, an RJ45 interface 102, a network transformer 103, a signal amplification circuit 104, a power interface 105, a first voltage circuit 106, a second voltage circuit 107, a third voltage circuit 108 and a filtering and coupling circuit 109. The HDMI interface 101 is used to receive HDMI signals from a host, and four pairs of differential AC signal pins (i.e., pins 1, 3, 4, 6, 7, 9, 10, and 12) for transmitting audio and video signals in the HDMI interface 101 are coupled to the signal input end of the network transformer 103, and the signal output end of the network transformer 103 is connected to the RJ45 interface 102 through the filtering and coupling circuit 109, and the pins for transmitting digital signals in the HDMI interface 101 (e.g., pins 15 and 16 for transmitting HDCP and EDID signals and pin 19 for transmitting HPD hot plug signals) are connected to the filtering and coupling circuit 109 through the signal amplification circuit 104. The power interface 105 is used to connect an external DC power supply. The power interface 105 is respectively connected to a first voltage circuit 106, a second voltage circuit 107 and a third voltage circuit 108. The first voltage circuit 106 converts the external DC power supply voltage into a first reference voltage and provides it to the network transformer 103. The second voltage circuit 107 converts the external DC power supply voltage into a second reference voltage and provides it to the signal amplification circuit 104. The third voltage circuit 108 boosts the external DC power supply voltage to a third reference voltage to form a power supply signal and provides it to the filtering and coupling circuit 109.

[0043] The peripheral circuit of the network transformer 103 is as follows Figure 2 As shown, the internal structure of its main component U1 is as follows Figure 3 As shown, the first voltage circuit 106 provides the first reference voltage (VCC33) to the network transformer 103, so that the voltage amplitude of the output signal of the network transformer 103 is increased to the first reference voltage (VCC33).

[0044] The signal amplifying circuit 104 is as follows Figure 4 As shown, the second voltage circuit 107 provides the signal amplifying circuit 104 with a second reference voltage (5V), which increases the voltage amplitude of the digital control signal (such as RX_IR, TX_IR and EDID) to the second reference voltage (5V) after being amplified by the amplifier U3.

[0045] Filter and coupling circuit 109 Figure 5 As shown, digital control signals (such as RX_IR, TX_IR and EDID) and power signals (12V) are coupled to audio and video signals (DO+, D0-, D1+, D1-, D2+, D2-, CLK+, CLK-), and are finally transmitted to the receiver 200 through the RJ45 interface 102 via the network cable.

[0046] The receiver 200 includes an HDMI interface 201, an RJ45 interface 202, a network transformer 203, a comparator circuit 204, a voltage regulator circuit 205, and a filtering and coupling circuit 206. The RJ45 interface 202 receives the signal from the transmitter 100, and the filtering and coupling circuit 206 separates the digital control signal and the power signal coupled to the audio and video signal. The audio and video signal is transmitted to the audio and video signal pin of the HDMI interface 201 through the network transformer 203, and the digital control signal is separated from the effective signal by the comparator circuit 204 and transmitted to the digital control signal pin of the HDMI interface 201. The power signal supplies power to the comparator circuit 204 through the voltage regulator circuit 205.

[0047] The filter and coupling circuit 206 of the receiver 200 has the same structure as the filter and coupling circuit 109 of the transmitter 100. The network transformer 203 of the receiver 200 adopts a network transformer structure with only a signal isolation function. The fourth reference voltage is set by the comparator circuit 204. When the digital control signal voltage is higher than the fourth reference voltage, it can be transmitted to the digital control signal pin of the HDMI interface 201 through the comparator circuit 204.

[0048] The working principle of the present invention is:

[0049] The present invention is different from the prior art that directly couples the audio and video signals with the digital control signals. The transmitter of the present invention uses a network transformer with boosting and isolation power to boost the voltage amplitude of the audio and video signals to the first reference voltage, and uses a signal amplification circuit to boost the voltage amplitude of the digital control signal to the second reference voltage. Then, a filtering and coupling circuit is used to couple the boosted audio and video signals with the digital control signal. In addition, in order to ensure the effective separation of the digital control signal, a comparator circuit is specially set in the receiver. Only when the voltage of the transmitted digital control signal is higher than the fourth reference voltage can it be transmitted to the HDMI interface through the comparator circuit. To achieve this function, the filtering and coupling circuit of the transmitter also boosts the power supply signal to the third reference voltage and couples it to the audio and video signal for transmission, and a voltage stabilizing circuit is set in the receiver to power the comparator circuit after stabilizing the separated power supply signal.

[0050] When the present invention is used for signal transmission, the audio and video signals use a rate of 1.65Gbit / s, and the digital control signals use a rate of 1MHz to 1MHz. When the amplitude of the first reference voltage differs from the second reference voltage by 30%, for example, the first reference voltage is 3.3V and the second reference voltage is 5V, the transmission in this way will reduce the interference between the audio and video signals and the digital control signals transmitted by the same cable, and can effectively increase the transmission distance. When CAT5E or CAT6 cables are used for transmission, the transmission distance can reach 100 to 150 meters. When the power signal is coupled in, the power signal is boosted to a third reference voltage, for example, 12V, which has a higher power transmission efficiency and will not interfere with the transmitted data signal.

[0051] As an improved embodiment, see Figure 1 The transmitter 100 further includes a control signal interface 110 and a microcontroller 111. The control signal interface 110 is used to receive an external control signal, such as a USB signal, an infrared signal, etc. The microcontroller 111 is coupled to the control signal interface 110 and the signal amplification circuit 104, respectively, and is used to convert the received external control signal into a serial control signal. The serial control signal is also amplified by the signal amplification circuit 104 and then coupled to the audio and video signal through the filtering and coupling circuit 109 for transmission.

[0052] As an improved embodiment, see Figure 1 The transmitter 100 also includes a transmitting end HDMI interface chip 112, which is coupled to the first HDMI interface 101 and the first network transformer 103 respectively, and is used to enhance the audio and video signals.

[0053] As an improved embodiment, the receiver 200 further includes a control signal interface 207, a microcontroller 208 and a receiving end HDMI interface chip 209. The control signal interface 207 is used to receive an external control signal. The microcontroller 208 is coupled to the control signal interface 207 and is used to convert the received external control signal into a serial control signal for transmission. The receiving end HDMI interface chip 208 is coupled to the second HDMI interface 201, the second network transformer 203, the comparator circuit 204 and the second microcontroller 208 respectively, and is used to integrate audio and video signals, digital control signals and external control signals, and transmit them to the second HDMI interface 201.

[0054] Of course, the present invention may have many other implementations. Based on this implementation, other implementations obtained by ordinary technicians in this field without any creative work are all within the scope of protection of the present invention.

Claims

1. An HDMI signal extension device, comprising a transmitter (100) and a receiver (200), characterized in that: The transmitter (100) comprises: A first HDMI interface (101), used for receiving an HDMI signal from a host; A first RJ45 interface (102), used for connecting to the receiver (200); A first network transformer (103) is coupled to the audio and video signal pins of the first HDMI interface (101) and is used to isolate and amplify the voltage of the transmitted audio and video signals; A signal amplification circuit (104), coupled to the digital control signal pin of the first HDMI interface (101), for amplifying the voltage of the transmitted digital control signal; A power interface (105), used for connecting to an external DC power source; A first voltage circuit (106) is coupled to the first network transformer (103) and the power interface (105) respectively, and is used to provide a first reference voltage for the first network transformer (103) so as to increase the voltage amplitude of the audio and video signal to the first reference voltage; A second voltage circuit (107) is coupled to the signal amplifying circuit (104) and the power interface (105) respectively, and is used to provide a second reference voltage for the signal amplifying circuit (104) so ​​as to increase the voltage amplitude of the digital control signal to the second reference voltage; A third voltage circuit (108), coupled to the power interface (105), and used for boosting the external DC power voltage to a third reference voltage to form a power signal; The first filtering and coupling circuit (109) is coupled to the first network transformer (103), the signal amplifying circuit (104), the third voltage circuit (108) and the first RJ45 interface (102) respectively, and is used to couple the digital control signal and the power supply signal to the audio and video signal for transmission.

2. The HDMI signal extension device according to claim 1, wherein the receiver comprises: A second HDMI interface (201), used for sending HDMI signals to a display terminal; A second RJ45 interface (202), used for connecting to the transmitter (100); A second network transformer (203), coupled to the audio and video signal pins of the second HDMI interface (201), and used to isolate the transmitted audio and video signals; A comparator circuit (204) coupled to the digital control signal pin of the second HDMI interface (201) and used to extract the transmitted digital control signal; A voltage stabilizing circuit (205), coupled to the comparator circuit (204), and used to provide power to the comparator circuit (204); The second filtering and coupling circuit (206) is coupled to the second network transformer (203), the comparator circuit (204), the voltage stabilizing circuit (205) and the second RJ45 interface (202) respectively, and is used to separate the digital control signal and the power supply signal coupled to the audio and video signal.

3. The HDMI signal extension device according to claim 1, characterized in that: The transmitter (100) further comprises: A first control signal interface (110), used for receiving an external control signal; The first microcontroller (111) is coupled to the first control signal interface (110) and the signal amplification circuit (104) respectively, and is used to convert a received external control signal into a serial control signal.

4. The HDMI signal extension device according to claim 1, characterized in that: The transmitter (100) further comprises: The transmitting end HDMI interface chip (112) is coupled to the first HDMI interface (101) and the first network transformer (103) respectively, and is used to enhance the audio and video signals.

5. The HDMI signal extension device according to claim 2, characterized in that: The receiver (200) further comprises: A second control signal interface (207), used for receiving an external control signal; A second microcontroller (208), coupled to the second control signal interface (207), configured to convert a received external control signal into a serial control signal for transmission; The receiving end HDMI interface chip (209) is respectively coupled to the second HDMI interface (201), the second network transformer (203), the comparator circuit (204) and the second microcontroller (208), and is used to integrate audio and video signals, digital control signals and serial control signals, and transmit them to the second HDMI interface (201).

6. The HDMI signal extension device according to claim 1, characterized in that: The amplitude of the first reference voltage differs from that of the second reference voltage by 30%.

7. The HDMI signal extension device according to claim 6, characterized in that: The first reference voltage is 3.3V, the second reference voltage is 5V, and the third reference voltage is 12V.

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