TWI692981B - Image display system and a method for increasing a data volume of a controlling signal thereof - Google Patents

Abstract

An image display system can increase data volume of a controlling signal in a frame of analog image so as to process an analog image in real time. A method for increasing the data volume of the controlling signal, which is used in the image display system, comprises increasing the time for sending the controlling signal, changing an encoding mode of the controlling signal to increase data volume which is sent in a unit time or outputting an analog image signal and the controlling signal at the same time. Therefore, the data volume of the controlling signal in a frame of image can be increased.

Description

Image display system and method for increasing control signal data volume

The invention relates to an image display system, in particular to an image display system for transmitting analog images and a method for increasing the amount of control signal data.

FIG. 1 shows a conventional image display system for transmitting analog high-definition images, which includes an analog video transmitting device 10, an analog video receiving device 12, and a coaxial cable 14 connecting the devices 10 and 12. The device 10 includes a camera 16 for capturing images, and transmits analog video signals to the device 12 via the coaxial cable 14. The analog video receiving device 12 can be implemented with a digital video recorder (Digital Video Recorder; DVR). The user can issue control commands from the control interface of the device 12 or its control device (such as a remote control), such as adjusting the angle of the camera 16 or The brightness of the image, etc., the device 12 generates a digital control signal according to the control command, and transmits the control signal to the device 10 through the coaxial cable 14. The analog video transmission device 10 analyzes the received control signal, and adjusts the settings according to the analysis result, such as adjusting the angle of the camera 16 or the brightness of the image, and then outputs an analog image different from the initial setting. The image display system of FIG. 1 can be applied to a driving recorder or a safety monitoring system. In the application of a security monitoring system, the distance between the devices 10 and 12 may be hundreds of meters, and the strength of the control signal transmitted on the coaxial cable 14 will attenuate with the increase of the transmission distance, affecting the control signal. reliability.

2 shows a timing diagram of signals on a coaxial cable 14 when a conventional image display system transmits an analog image of a frame, which includes a vertical synchronization signal interval 20 for confirming the start or end of each frame of image, and a digital control signal The interval 22 is used for transmitting control signals and an analog image interval 24 is used for transmitting analog video signals. In order to avoid mutual influence of the digital control signals and the analog video signals, the timing of transmitting the control signals and the analog video signals must be staggered. When the frame per second (FPS) is fixed, the time to transmit a frame of analog video is also fixed, so when the resolution increases and the amount of data of the analog video signal becomes larger, more time is required to transmit the analog For video signals, the existing technology is to shorten the digital control signal interval 22 to increase the time of the analog video interval 24. However, shortening the digital control signal interval 22 will reduce the amount of control signal data that can be transmitted during the transmission of a frame of image, resulting in the inability to transmit all the control signals within a frame of image. Therefore, it takes several frames to complete the transmission All the control signals, which will make the user feel obvious non-real-time when controlling the analog video transmission end, can not meet some of the needs of fast response speed. The above shortcomings also limit the development of other applications that require a large number of control commands or parameters in the image display system.

One object of the present invention is to propose an image display system and method for increasing the amount of control signal data.

One of the objectives of the present invention is to propose an image display system and method using vertical signal synchronization intervals to transmit control signals.

One of the objectives of the present invention is to propose an image display system and method using horizontal signal synchronization intervals to transmit control signals.

One of the objectives of the present invention is to propose a control signal encoding method to increase the amount of control signal data transmitted per unit time of the image display system.

One of the objects of the present invention is to propose an image display system and method capable of simultaneously transmitting analog image signals and control signals.

According to the present invention, an image display system includes an analog image transmitting end device for outputting an analog image signal, an analog image receiving end device for receiving the analog image signal and outputting digital control signals to the analog image transmitting end device and a The coaxial cable connects the analog video transmitting device and the analog video receiving device. In the process of transmitting a frame of analog video, the signal timing of the coaxial cable includes a vertical synchronization signal interval, a digital control signal interval, and an analog image interval. The method for increasing the amount of control signal data of the image display system includes setting a first additional control signal interval, the digital control signal interval and the first in the vertical synchronization signal interval without changing the time length of the vertical synchronization signal interval The additional control signal interval can be used to transmit the control signal.

The method for increasing the amount of control signal data of the image display system further includes setting a second additional control signal interval in the horizontal synchronization signal interval for transmitting the control without changing the time length of the horizontal synchronization signal interval in the analog image interval Signal.

The method for increasing the amount of control signal data of the image display system further includes setting the signal period of the control signal to an integer multiple of at least two pixel clocks.

The method for increasing the amount of control signal data of the image display system further includes using the duty cycle of each signal cycle of the control signal to represent the encoded data transmitted in each signal cycle, and transmitting at least two bits of data per signal cycle.

The method for increasing the amount of control signal data of the image display system further includes transmitting the control signal and the analog image signal simultaneously to increase the time for transmitting the control signal. After receiving the superimposed signal generated by superimposing the control signal and the analog image signal, the analog image receiving end device uses a subtractor to subtract the superimposed signal from the control signal to obtain the analog image signal. After receiving the superimposed signal, the analog image transmission device uses a preset voltage to obtain the part of the superimposed signal related to the control signal, and then parses out the content of the control signal.

FIGS. 3 and 4 illustrate the first method of the present invention to increase the amount of control signal data. FIG. 3 shows a conventional vertical signal synchronization interval 20, and FIG. 4 shows an embodiment of the vertical signal synchronization interval 26 of the invention. Figures 3 and 4 take the image resolution of 720P as an example, and the period of one frame of image includes the time of 750 scanning lines SL1-SL750. Scanning lines are the basic elements of analog image signals, also known as horizontal scanning lines, which are sorted by dots in the horizontal direction to form lines with color information. Because the sorting method is from left to right, they are called scanning lines. In FIGS. 3 and 4, scan lines L1-L7 are vertical sync signal intervals 20 or 26, scan lines L8-L30 are digital control signal intervals 22, scan lines L31-L750 are analog image intervals 24, and scan lines L1- L30 is also called Vertical Blank Interval (VBI). In the vertical blanking interval, no analog video signal is transmitted, and only in the analog video interval 24 will the analog video signal be transmitted.

As shown in FIG. 3, the conventional vertical synchronization signal interval 20 is composed of a pre-equalizing pulse interval A, a vertical sync pulse (vertical sync pulse) interval B, and a post-equalizing pulse. The interval C consists of. The interval D in the intervals A, B and C represents the time length of one scanning line, and the interval E represents the time length of half a scanning line, so the intervals A and B in FIG. 3 are the time lengths of 5 half scanning lines each , Section C is the time length of 4 half scan lines. The low-level interval F in the intervals A and C is called equalizing low pulse. The high-level interval G in the interval B is called a sync pulse. The functions of the intervals A, B, C, F and G are well known to those skilled in the art, so they will not be repeated here. The method for increasing the amount of control signal data of the image display system of the present invention is to shorten at least one of the intervals A, B, and C to obtain additional time to transmit the control signal and increase the amount of control signal data in a frame of image.

Referring to FIGS. 1 and 4, the image display system of the present invention also includes an analog video transmission device 10, an analog video reception device 12 and a coaxial cable 14 as shown in FIG. 1, but as shown in the embodiment of FIG. 4, The equalization pulse interval A'and the vertical synchronization pulse interval B'are shortened from the time length of the conventional half scan lines to one half scan line, and the post-equalization pulse interval C'is the same as the conventional The time length of 4 half scan lines, the shortened pre-equalization pulse interval A', vertical synchronization pulse interval B'and post-equalization pulse interval C'only use the three scan lines L1- in the vertical synchronization signal interval 26 At the time of L3, the remaining scanning lines L4-L7 in the vertical synchronization signal interval 26 can be set as an additional control signal interval 28 for transmitting control signals, thereby increasing the amount of control signal data in a frame of image. The present invention can support different display formats such as 720P and 1080P, as well as different frame numbers such as 24, 25, 30, 50, and 60 FPS, as well as other expansions and transformations.

5 to 9 are used to illustrate the second method of the present invention to increase the amount of control signal data. FIG. 5 shows the timing of one scan line in the analog video interval 24 in FIG. 3, which includes a horizontal sync signal interval 30 and a analog video signal interval 32. FIG. 6 shows the timing of the conventional horizontal sync signal section 30, which includes a horizontal front porch section HFP, a horizontal sync width (horizontal sync width) section HSW, and a horizontal back porch section HBP , Where the interval HBP includes a buffer segment (breeze-way) interval BRW and a burst width (burst width) interval BUW, where the role of the intervals HFP, HSW, HBP, BRW and BUW is well known to those skilled in the art, so it is not Repeat again. The method for increasing the amount of control signal data of the image display system of the present invention is to shorten at least one of the intervals HFP, HSW, HBP, BRW, and BUW to obtain additional time to transmit the control signal and increase the amount of control signal data in a frame of image.

FIG. 7 shows an embodiment of the timing of the horizontal synchronization signal interval 30 of the present invention, which has the horizontal leading edge interval HFP, the horizontal synchronization width interval HSW, the horizontal trailing edge interval HBP, the buffer segment interval BRW, and the pulse burst as in FIG. 6. The width interval BUW, the length of the horizontal synchronization signal interval 30 in FIG. 6 and FIG. 7 is the same, but at least one of the intervals HFP, HSW, HBP, BRW and BUW in FIG. 7 is shortened, so that the intervals HFP, HSW and The total length of the HBP is shorter than the total length of the HFP, HSW, and HBP sections in FIG. 6, so there is extra time in the horizontal synchronization signal section 30 of FIG. 7 that can be set as an additional control signal section 34 for transmission of control signals, thus adding one frame The amount of control signal data in the image. FIG. 8 shows the lengths of HFP, HSW, HBP, BRW, and BUW in each section in FIGS. 6 and 7 at a resolution of 720P. In the embodiment of FIG. 8, the length of the conventional section HFP in FIG. 6 is 23.70 μs, and the interval HFP of the present invention in FIG. 7 is reduced to 1.24 μs, so that the total length of the interval HFP, HSW, and HBP in FIG. 7 is shorter than the total length of the interval HFP, HSW, and HBP in FIG. 6. The values shown in FIG. 8 are only one of the embodiments. Those skilled in the art can adjust the time lengths of the intervals HFP, HSW, HBP, BRW, and BUW in FIG. 7 according to requirements, so that the total time lengths of the intervals HFP, HSW, and HBP are less than The length of the conventional time increases the additional control signal interval 34. In addition to the specifications of common image display systems such as 25FPS, 30FPS, 60FPS, 720P, and 1080P, the present invention can also support the transformation and amplification of other image formats, such as the transformation/amplification 1 shown in FIG. 9 and Transform/Amplify 2.

When the FPS and resolution are fixed, the length of the scan line is fixed, and the analog video signal interval 32 is also fixed. If the total length of HFP, HSW, and HBP in the horizontal synchronization signal interval 30 is shorter, the additional control signal interval 34 can be increased, so that the interval length of transmitting digital control signals can be enlarged. In order to support the deformation of the analog video signal specification, it is also necessary to adjust the carrier frequency of the subcarrier (subcarry) to reduce the interference of noise when the analog video signal is transmitted through the coaxial cable 14 and ensure that the analog video receiving device 12 can receive it correctly Analog video signal.

10 to 12 are used to illustrate the third method of the present invention to increase the amount of control signal data. FIG. 10 shows a conventional digital control signal, which has a longer signal period TL. Taking 720P as an example, the signal period TL is 3 μs. FIG. 11 shows the coding method of the conventional control signal, which divides each signal period TL1 and TL2 into three sub-intervals, and then distinguishes the transmission of the signal period by comparing whether the time of the high level in the signal period is greater than the time of the low level Encoding data, for example, the three sub-intervals of the signal period TL1 show "high", "low" and "low", so the time of the high level in the signal period TL1 is less than the time of the low level, which means that the encoded data of the signal period TL1 To encode 0, and the three sub-intervals of the signal period TL2 show "high", "high" and "low" respectively, so the time of the high level in the signal period TL2 is greater than the time of the low level, which means that the encoded data of the signal period TL2 Is code 1. 12 shows the digital control signal of the present invention, which has a shorter signal period TS, so the control signal of the present invention can transmit a coded data in a shorter period TS, in other words, the present invention shortens the time for transmitting a coded data. Taking the encoding method of FIG. 11 as an example, suppose the signal period TS of the present invention has three sub-intervals, and the length of each sub-interval is 2 pixel clocks, then the signal period TS is 2 pixel clocks. 3 times, that is to say, the signal period TS is an integer multiple of 2 pixel clocks. Taking 720P as an example, one pixel clock is 1/74.25MHz=0.01346μs, so the signal period TS=2*0.01346*3=0.08076 μs, which is much lower than the conventional signal period TL=3μs, the time for the conventional control signal to transmit one encoded data, the control signal of the present invention can transmit about 38 encoded data, the present invention can improve the control signal transmission in unit time The amount of data. In this embodiment, the length of a sub-interval is 2 pixel clocks, but in other embodiments, the length of a sub-interval may also be more than 2 pixel clocks, that is, the signal period TS of the present invention is at least An integer multiple of the clock frequency of the two pixels, but the signal period TS must be less than the conventional signal period TL.

13 to 15 illustrate the fourth method of the present invention to increase the amount of control signal data. 13 shows the encoding method of the control signal of the present invention, which uses Pulse Width Modulation (Pulse Width Modulation; PWM) technology to adjust the duty cycle of the signal cycle TN to indicate that the encoded data transmitted by the signal cycle TN is code 0 To one of the codes 15. In the embodiment of FIG. 13, the duty cycle of a signal cycle TN of a control signal can have 16 changes corresponding to codes 0 to 15, respectively, which can represent binary data of "0000" to "1111", so it is equivalent to a The signal cycle TN can transmit 4 bits of data, which increases the amount of data transmitted by the control signal per unit time. Fig. 14 shows the conventional control signal on a scanning line, which has 8 signal periods TN, and as shown in Fig. 11, a conventional signal period can only send code 0 and code 1 and can only represent "0" and The binary data of "1", so a signal period TN is equivalent to transmitting only one bit of data, and a scanning line is equivalent to transmitting 8 bits of data. FIG. 15 shows the control signal of the present invention on one scanning line, which has 8 signal periods TN, and as shown in FIG. 13, each signal period TN can transmit 4 bits of data, so one scanning line is equivalent to transmitting The data amount of 32 bits, that is, under the same time length, the control signal of the present invention has four times the amount of data as the conventional control signal. In this embodiment, there are 16 variations of the duty cycle of the signal cycle TN, but in other embodiments, the duty cycle of the signal cycle TN may have more or less variations, for example, the duty cycle of the signal cycle TN has 32 This change is equivalent to transmitting 5 bits of data, or there are 4 changes in the signal cycle TN duty cycle, which is equivalent to transmitting 2 bits of data.

The embodiments of FIG. 12 and FIG. 13 can be combined. Assuming that the signal period TN in FIG. 13 is divided into 17 sub-intervals to achieve 16 changes of the duty cycle, the length of each sub-interval is 2 pixel clocks. Taking 720P as an example, one The pixel clock is 1/74.25MHz=0.01346μs, so the signal period TN is about 0.458μs, that is, in this embodiment, the present invention can use 0.458μs to transmit the amount of 4 bits of data, compared with the conventional technology. 3μs transmits 1 bit of data, the efficiency of the present invention to transmit control signals is increased by 26 times.

16 to 19 are used to explain the fifth method of the present invention to increase the amount of control signal data. As shown in FIG. 2, the conventional image display system transmits the control signal in the digital control signal interval 22 after the vertical synchronization signal interval 20 and before the analog image interval 24, that is, the time when the conventional image display system will transmit the control signal The timing of the transmission of the analog video signal is staggered, so as to avoid the overlapping of the control signal and the analog video signal, which may cause anomalies in the screen and the inability to read the control signal correctly. 16 shows an interval 36 in which the image display system of the present invention can transmit control signals. As shown in FIG. 16, the image display system of the present invention can be used to transmit control signals at all times except the vertical synchronization signal interval 20, including analog images In the interval 24, even if the control signal and the analog image signal are simultaneously transmitted, the control signal and the analog image signal can be accurately obtained, so the interval in which the control signal can be transmitted becomes wider, and more control signal data can be transmitted in a frame of analog image.

17 and 18 show an image display system for simultaneously transmitting a control signal and an analog image signal. FIG. 17 shows an analog image receiving device 12 of the image display system of the present invention. FIG. 18 shows an analog image transmission of the image display system of the present invention.端装置10。 End device 10. 17, the analog video receiving device 12 of the present invention includes a subtractor 40, a digital control signal output unit 42, an analog digital conversion unit 44, the subtractor 40 is coupled to the coaxial cable 14, the digital control signal output unit 42 and the analog digital Conversion unit 44. The digital control signal output unit 42 outputs the control signal Sc to the analog video transmission terminal device 10 via the coaxial cable 14. When the control signal Sc and the analog video signal Sai are input to the coaxial cable 14 at the same time, the control signal Sc is superimposed on the analog video signal Sai A superimposed signal Sol is formed, and the subtractor 40 receives the superimposed signal Sol and then subtracts it from the control signal Sc to obtain the original analog video signal Sai. The analog digital conversion unit 44 converts the analog video signal Sai output from the subtractor 40 into a digital signal To display the image on the monitor. Since the analog image receiving end device 12 removes the component of the control signal Sc in the superimposed signal Sol by the subtractor 40, the original analog image signal Sai can be obtained, so the picture displayed on the analog image receiving end device 12 will not be abnormal.

Referring to FIG. 18, the analog video transmission device 10 of the present invention includes a voltage level comparison circuit 46, a voltage level shifter 48, and a digital signal analysis unit 50. The voltage level comparison circuit 46 is coupled to the coaxial cable 14 and the voltage Between the level shifters 48, the analog video transmitting device 10 outputs the analog video signal Sai to the analog video receiving device 12 via the coaxial cable 14, when the control signal Sc and the analog video signal Sai are input to the coaxial cable 14 at the same time , The control signal Sc and the analog video signal Sai are superimposed to form a superimposed signal Sol. The voltage level comparison circuit 46 receives the superimposed signal Sol, and compares the superimposed signal Sol with a preset voltage Vpre to generate a comparison signal Scomp. Generally, the voltage of the analog video signal Sai is below 1.2V, and the control signal Sc is above 1.2V, so Setting the preset voltage Vpre to 1.2V can filter the analog video signal components below 1.2V in the superimposed signal Sol to generate a comparison signal Scomp related to the control signal Sc. The voltage value of the preset voltage Vpre can be set according to requirements, not limited to 1.2V. The voltage level shifter 48 receives the comparison signal Scomp from the voltage level comparison circuit 46 and converts the voltage value of the comparison signal Scomp to generate a voltage level signal Sls. In one embodiment, the voltage level shifter 48 converts the voltage value of the comparison signal Scomp to a voltage value that matches the operating voltage of the analog image transmitting device 10 to generate a voltage level signal Sls, for example, to 2.5V Or 3.3V. The digital signal analysis unit 50 receives and analyzes the voltage level signal Sls to obtain the content of the control signal Sc. The voltage level comparison circuit 46, the voltage level shifter 48, and the digital signal analysis unit 50 can also be integrated into one IC.

FIG. 19 shows another embodiment of the analog video transmission device 10 shown in FIG. 18, which includes an operational amplifier 52 and a digital signal analysis unit 50. The operational amplifier 52 receives the superimposed signal Sol and amplifies the superimposed signal Sol and the preset voltage with a gain The difference of Vpre generates a voltage level signal Sls. By controlling the gain of the operational amplifier 52, the voltage value of the signal Sls can be made to match the voltage value of the operating voltage of the analog video transmission device 10. The digital signal analysis unit 50 receives and analyzes the signal Sls To get the content of the control signal Sc.

As mentioned above, the present invention discloses several methods for increasing the amount of control signal data in a frame of image. These methods can be used alone or combined with each other. For example, in one embodiment, except in the vertical sync signal interval 20 In addition to the additional control signal interval 28 shown in FIG. 4, an additional control signal interval 34 shown in FIG. 7 is also set in the horizontal synchronization signal interval 30, and the control signal can also be shown in FIGS. 12 and 13 Encoding method, and finally combined with the circuit structure of FIG. 17 and FIG. 18, so that the control signal Sc and the analog video signal Sai can be transmitted through the coaxial cable 14 at the same time.

The method proposed by the present invention can transmit more control signal data during the transmission of a frame of image, so in some applications that require a large amount of control signals and require fast response, such as fisheye image correction, the present invention can enable an image display system Realize high-efficiency and immediate control. The embodiment of FIG. 20 shows an analog image transmission device 10 having a fish-eye image correction function, which includes a fish-eye camera 54, a fish-eye correction technology unit 56, a digital analog conversion unit 58, and a digital signal analysis unit 60. In one embodiment, the fish-eye camera 54 has a viewing angle of 180 degrees or more, and can shoot a scene with a range of 180 degrees or more to generate a fish-eye image Dfi. The digital signal analysis unit 60 is used to decode the control signal output by the analog image receiving device 12 (not shown) to obtain the image correction parameters Dcp required for fisheye image correction, and transmit these parameters Dcp to the fisheye Correction technology unit 56. The fish-eye correction technical unit 56 includes a fish-eye correction algorithm, and implements the fish-eye correction algorithm to adjust the fish-eye image Dfi according to the image correction parameters Dcp to achieve the effect of image correction, and convert the corrected digital image signal Dfc Transfer to the digital to analog conversion unit 58. The digital-analog conversion unit 58 converts the corrected digital image signal Dfc into an analog image signal, and outputs the analog image signal to the analog image receiving device 12 through the coaxial cable 14 (not shown). Applying the method of the present invention can allow the parameters Dcp required for fisheye image correction to be transmitted as quickly as possible in one frame of image, which is helpful for the fisheye lens image display system to achieve real-time fisheye correction control. First, the fisheye lens can be used in more occasions. For example, the blind spot detection (BSD) of the in-vehicle system can be implemented using a fisheye lens, and the user can obtain the vehicle side vehicle arrival in real time. Image information can significantly improve the safety of driving. Compared with the blind spot detection system using radar in the existing car, the cost of the blind spot detection system using fisheye lens is cheaper. Furthermore, the blind spot detection system using a fisheye lens can obtain images on the side of the vehicle to develop more applications. This advantage is not possible with the blind spot detection system using radar.

The fisheye correction-related functions that the fisheye correction technology unit 56 can implement include at least acceleration correction (Hw-acc), spherical image to square linear image (hemispherical to rectilinear image), horizontal pan (til), tilt (tilt), zoom Room, flip, mirror, rotation, and multi-view, therefore, the control signal transmitted from the analog image receiving device 12 to the analog image transmitting device 10 includes at least The following parameters: Image center position(x,y): fisheye image center position; Fish-eye compensation/Panorama compensation parameter: the compensation parameter of fish-eye image or panoramic image. In fish-eye image or panoramic image, the different degree of deformation of each area will use different compensation parameters; Output window image width/hight: The output window size setting determines the height and width of a window displayed on the screen; Shift X/Y: used to determine the position of a window on the screen; ROTATE_ANGLE: the rotation angle of the window and the corrected image; keystone center X/Y: the center position of the trapezoid image, used for the adjustment of the trapezoid image; zoom ration: the enlargement or reduction ratio of the image; optical center: the optical center of the fisheye lens; outside/inside radius: used to determine the correction range of the 360-degree panoramic fisheye image; start angle: used to determine the starting point of correction after the 360-degree panoramic fisheye image is converted into a square linear image; and Angle range: used to determine the correction range after the 360-degree panoramic fisheye image is converted into a square linear image, used to take a part of the 360-degree panoramic image for correction.

The above is only a fisheye lens to illustrate the application embodiment of the present invention, and any wide-angle lens can be applied to the present invention.

21 and 22 show the fisheye lens image correction and control achieved by the image display system of the present invention according to the aforementioned parameters. Fig. 21 shows the distribution of the fisheye lens image window on the display 62. The fisheye lens image can be displayed by a single window 64, or can be divided into multiple parts and displayed on multiple windows 64, the position and position of each window 64 The size can be adjusted by the user and can overlap. Figure 22 shows the rotation, scaling, deformation, or displacement of the fisheye lens image window or screen. The displacement of the screen can be achieved by adjusting the angle of view of the fisheye lens. For example, the original screen includes the text "window". The screen moves to the left, so that the text on the screen is left as "view". Figure 22 shows an example of the deformation of the two screens 66, which is to indent or bulge the left and right sides of the original square image. FIGS. 21 and 22 show only a part of the fisheye lens image correction and control. Other fisheye lens image correction and control not disclosed in FIGS. 21 and 22 can also be achieved by the image display system of the present invention.

The above description of the preferred embodiment of the present invention is for the purpose of clarification, and is not intended to limit the present invention to the disclosed form precisely. Modifications or changes are possible based on the above teaching or learning from the embodiments of the present invention The embodiments are selected to explain and explain the principles of the present invention and allow those skilled in the art to use the present invention in various embodiments in practical applications. The technical idea of the present invention is intended to be derived from the scope of patent applications and their equivalents Decide.

10: Analog video transmission device 12: Analog video receiving device 14: coaxial cable 16: camera 20: Vertical sync signal interval 22: Digital control signal interval 24: Analog image interval 26: Vertical sync signal interval 28: additional control signal interval 30: Horizontal sync signal interval 32: Analog video signal interval 34: additional control signal interval 36: Can send control signal interval 40: subtractor 42: digital control signal output unit 44: Analog digital conversion unit 46: Voltage level comparison circuit 48: voltage level shifter 50: digital signal analysis unit 52: Error amplifier 54: Fisheye camera 56: Fisheye correction technology unit 58: digital analog conversion unit 60: digital signal analysis unit 62: display 64: Windows 66: Picture

Figure 1 shows a conventional image display system. FIG. 2 shows a conventional timing diagram for transmitting a frame of analog video. Figure 3 shows the conventional vertical signal synchronization interval. FIG. 4 shows an embodiment of the vertical signal synchronization interval of the present invention. Figure 5 shows the timing of one scan line in the analog video interval. FIG. 6 shows the timing of the conventional horizontal synchronization signal interval. 7 shows the timing of the horizontal synchronization signal interval of the present invention. FIG. 8 shows an example of the length of each section in FIGS. 6 and 7. FIG. 9 shows an embodiment of the horizontal synchronization signal interval in different formats. Figure 10 shows conventional digital control signals. Fig. 11 shows the coding method of the conventional control signal. FIG. 12 shows the digital control signal of the present invention. FIG. 13 shows the encoding method of the control signal of the present invention. Fig. 14 shows conventional control signals on a scanning line. FIG. 15 shows the control signal of the present invention on a scanning line. FIG. 16 shows an interval in which the image display system of the present invention can transmit control signals. FIG. 17 shows an analog video receiving device of the video display system of the present invention. FIG. 18 shows the analog video transmission device of the video display system of the present invention. FIG. 19 shows another embodiment of the analog video transmission device in FIG. 18. Fig. 20 shows an analog video transmission device with a fisheye image correction function. Figure 21 shows the distribution of the fisheye lens image window on the display. Figure 22 shows the rotation, scaling, deformation or displacement of the fisheye lens image window or screen.

22: Digital control signal interval

24: Analog image interval

26: Vertical sync signal interval

28: additional control signal interval

Claims (19)

An image display system includes: an analog image transmitting end device for outputting analog image signals; an analog image receiving end device for receiving the analog image signals and outputting digital control signals to the analog image transmitting end device; And a coaxial cable connecting the analog video transmitting device and the analog video receiving device; wherein, in the process of transmitting a frame of analog video, the signal timing on the coaxial cable includes a vertical synchronization signal interval and a digital control A signal interval and an analog image interval, the vertical synchronization signal interval includes a first additional control signal interval, the digital control signal interval and the first additional control signal interval are used to transmit the control signal; wherein, the analog image transmission end device includes : A fisheye camera to generate a fisheye image; a digital signal analysis unit to receive and decode the control signal to obtain an image correction parameter; a fisheye correction technology unit to connect the fisheye camera and the digital signal analysis The unit corrects the fish-eye image according to the image correction parameters to generate a corrected digital image signal; and a digital analog conversion unit is connected to the fish-eye correction technology unit to convert the digital image signal into the analog image signal. The image display system of claim 1, wherein the first additional control signal interval is generated by shortening at least one of the pre-equalization pulse interval, the vertical synchronization pulse interval, and the post-equalization pulse interval in the vertical synchronization signal interval . The image display system according to claim 1, wherein the analog image interval includes a horizontal synchronization signal interval and an analog image signal interval, and the horizontal synchronization signal interval includes a second additional control signal interval for transmitting the control signal. The image display system according to claim 3, wherein the second additional control signal interval is by shortening the horizontal leading edge interval, the horizontal synchronization width interval, the horizontal trailing edge interval, the buffer segment interval, and the burst width in the horizontal synchronization signal interval Produced by at least one of the intervals. As in the image display system of claim 1, wherein the signal period of the control signal is an integer multiple of at least two pixel clocks. As in the image display system of claim 1, wherein each signal period of the control signal transmits at least two bits of data, and the encoded data transmitted in each signal period is represented by its working period. As in the image display system of claim 1, wherein when the analog image transmitting device outputs the analog image signal, the analog image receiving device outputs the control signal and the analog image signal to form a superimposed signal, the analog image receiving end The device includes: a digital control signal output unit that provides the control signal to the coaxial cable; a subtractor that receives the superimposed signal and receives the control signal from the digital control signal output unit, and subtracts the superimposed signal from the control The signal obtains the analog video signal; and an analog digital conversion unit, connected to the subtractor, converts the analog video signal output by the subtractor into a digital signal to display the image on the display. As in the image display system of claim 1, wherein when the analog video transmitting device outputs the analog video signal, the analog video receiving device outputs the control signal and the analog video signal to form a superimposed signal, and the analog video transmitting end The device further includes: a voltage level comparison circuit, receiving the superimposed signal, and comparing the superimposed signal with a preset Voltage comparison to remove the analog image signal in the superimposed signal to generate a comparison signal; and a voltage level shifter connected to the voltage level comparison circuit to convert the voltage value of the comparison signal to generate a voltage bit Standard signal; wherein, the digital signal analysis unit is connected to the voltage level shifter to analyze the voltage level signal to obtain the content of the control signal. The image display system according to claim 1, wherein when the analog image transmitting device outputs the analog image signal, the analog image receiving device outputs the control signal and the analog image signal to form a superimposed signal, and the analog image transmitting device It further includes: an operational amplifier, receiving the superimposed signal, and amplifying the difference between the superimposed signal and a preset voltage with a gain to generate a voltage level signal, wherein the voltage value of the voltage level signal is controlled by controlling the gain A voltage value conforming to the operating voltage of the analog video transmission device; wherein the digital signal analysis unit is connected to the operational amplifier to analyze the voltage level signal to obtain the content of the control signal. A method for increasing the amount of control signal data of an image display system. The image display system includes an analog image transmitting end device for outputting an analog image signal, and an analog image receiving end device for receiving the analog image signal and outputting digital control signals to The analog image transmitting end device and a coaxial cable connect the analog image transmitting end device and the analog image receiving end device, and in the process of transmitting a frame of analog image, the signal timing on the coaxial cable line includes a vertical synchronization signal interval, a A digital control signal interval and an analog video interval. The method for increasing the amount of control signal data includes the following steps: without changing the time length of the vertical synchronization signal interval, setting a first additional control signal in the vertical synchronization signal interval Interval Use the first additional control signal interval to transmit the control signal to increase the amount of the control signal data; and perform the following steps at the analog image transmission end device: use the fisheye camera to generate a fisheye image; receive and decode the control signal to Obtain an image correction parameter; correct the fish-eye image according to the image correction parameter to generate a corrected digital image signal; and convert the digital image signal into the analog image signal. The method for increasing the amount of control signal data in claim 10, wherein the step of setting a first additional control signal interval includes shortening the pre-equalization pulse interval, the vertical synchronization pulse interval, and the post-equalization pulse interval in the vertical synchronization signal interval At least one to obtain the first additional control signal interval. For example, the method for increasing the amount of control signal data in claim 10 further includes the following steps: without changing the length of the horizontal synchronization signal interval in the analog image interval, setting a second additional control signal in the horizontal synchronization signal interval Interval; and using the second additional control signal interval to transmit the control signal to increase the data amount of the control signal. The method for increasing the amount of control signal data according to claim 12, wherein the step of setting a second additional control signal interval includes shortening the horizontal leading edge interval, the horizontal synchronization width interval, the horizontal trailing edge interval, and the buffer section in the horizontal synchronization signal interval At least one of the interval and the burst width interval to obtain the second additional control signal interval. For example, the method for increasing the amount of control signal data in claim 10 further includes setting the signal period of the control signal to an integer multiple of at least two pixel clocks. For example, the method for increasing the amount of control signal data in claim 10 further includes using the duty cycle of each signal cycle of the control signal to represent the encoded data transmitted in each signal cycle, wherein each control signal of the control signal transmits at least two The amount of data in bits. For example, the method for increasing the amount of control signal data in claim 10 further includes that when the analog video transmitting device outputs the analog video signal to the analog video receiving device, the analog video receiving device simultaneously outputs the control signal to the analog video The transmitter device. For example, the method for increasing the amount of control signal data in claim 16, wherein the analog image receiving end device performs the following steps after receiving the superimposed signal formed by superimposing the control signal and the analog image signal: subtracting the control from the superimposed signal The signal obtains the analog image signal; and converts the analog image signal into a digital signal to display the image on the display. For example, the method for increasing the amount of control signal data in claim 16, wherein after receiving the superimposed signal formed by superimposing the control signal and the analog video signal, the analog image transmitting end device performs the following steps: the superimposed signal and a preset Voltage comparison to remove the analog image signal in the superimposed signal to generate a comparison signal; convert the voltage value of the comparison signal according to the operating voltage of the analog image transmission device to generate a voltage level signal; and analyze the voltage level Standard signal to get the content of the control signal. For example, the method for increasing the amount of control signal data in claim 16, wherein after receiving the superimposed signal formed by superimposing the control signal and the analog video signal, the analog image transmitting end device performs the following steps: amplifying the superimposed signal and A difference of a preset voltage generates a voltage level signal, wherein the voltage value of the voltage level signal conforms to the analog by controlling the gain The voltage value of the working voltage of the image transmitting end device; and analyzing the voltage level signal to obtain the content of the control signal.

Images