JP3661497B2 - Automatic adjustment device and video projector - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an automatic adjustment device (International Patent Classification H04N 5/66) in a video display device such as a display device or a video projector.
[0002]
[Prior art]
In recent years, display devices capable of supporting multiple signal sources have been attracting attention in the trend toward multimedia.
[0003]
As a conventional automatic adjustment device, there is a liquid crystal display device described in JP-A-2-309773.
This utilizes the characteristic that the signal amplitude of the video signal component input to the liquid crystal is small when the clock phase is shifted and the signal amplitude is large when the clock phase is close to the optimum. Specifically, a video signal is converted into a direct current to generate a signal corresponding to a clock phase shift, and this signal is compared with a reference signal, and a clock having a clock phase shift signal equal to or higher than the reference signal is automatically selected.
[0004]
[Problems to be solved by the invention]
As described above, the method of automatically adjusting the clock phase using the signal input to the liquid crystal by the automatic adjustment device is such that the level of the input signal is larger than the level of the reference signal to be compared with the signal corresponding to the clock phase shift. Therefore, there is a problem that input video signals that can be automatically adjusted are limited.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the automatic adjustment device of the present invention controls the amplitude adjustment device by microcomputer control and inputs the video signal whose signal amplitude is overcorrected to the analog-to-digital conversion device, and performs signal processing on the output digital signal The optimum clock phase and the display position and shape information for the input video signal from the signal processing device input to the device and the display position and shape information are read by the microcomputer, and the clock phase of the optimum analog-digital converter is adjusted and the display control device is controlled by the microcomputer. An automatic adjustment device and a video projector characterized by adjusting a display position and a display shape of an image.
[0006]
According to the present invention, even if the input is an analog video signal with a small amplitude, the signal output converted into a digital signal retains information on the presence / absence of the video signal, and based on this information, the clock phase of the optimum analog / digital conversion device The display position and display shape of the video can be adjusted.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The invention described in claim 1 of the present invention
A microcomputer,
An amplitude control device that receives an analog video signal 1 output from a computer and is controlled in amplitude by an amplitude adjustment signal from the microcomputer;
An analog-to-digital converter that inputs the analog video signal 2 output of the amplitude control device and performs analog-to-digital conversion;
A clock control device that performs analog-to-digital conversion and controls the frequency and phase of a clock that is oscillated by the control of the microcomputer with reference to a horizontal synchronization signal;
A function 1 for inputting the digital video signal 1 produced by the analog-digital converter and counting the number of MSBs;
A function 2 for measuring the number of clocks Hc from when the horizontal synchronizing signal is input to when the MSB of the digital video signal 1 is first input;
A function 3 for measuring the horizontal synchronization signal Vc from the timing at which the vertical synchronization signal is input until the one MSB of the digital video signal is first input;
A function 4 for measuring the number of clocks from the timing at which the MSB of the digital video signal 1 is first input between horizontal synchronization signals to the timing at which the MSB is finally input;
A function 5 for measuring the number of horizontal synchronization signals from the timing at which the MSB of the digital video signal 1 is first input between the vertical synchronization signals to the timing at which the MSB is finally input, and is controlled by the microcomputer A signal processing device that outputs the digital video signal 2 by changing the digital video signal 1 converted from analog to digital based on the measured value;
A memory for taking in the output of the digital video signal 2 varied by the control of the microcomputer and the signal processing device;
With
When operating the automatic adjustment device,
The voltage amplitude correction in the amplitude adjustment device is overcorrected,
The number Nn of MSBs measured in the signal processing device is measured a plurality of times, the change amount An = | N n −N (n−1) | is calculated, and the clock phase at which An becomes the minimum is optimized. Control the phase of the clock to oscillate under the control of the microcomputer as the correct clock phase,
An automatic adjustment device that varies a digital video output from the memory based on a horizontal resolution calculated by the function 4 of the signal processing device and a vertical resolution calculated by the function 5. Even if the input is an analog video signal with a small amplitude, the signal output converted to a digital signal retains information on the presence or absence of the video signal, and based on this information, the clock phase and video display position of the optimal analog-digital converter The display shape can be automatically adjusted.
[0008]
Next, a second aspect of the present invention is a video projector comprising the automatic adjustment device according to the first aspect, wherein the digital signal is input even if the input is an analog video signal having a small amplitude. The signal output converted into a video projector holds information on the presence or absence of a video signal, and based on this information, it is a video projector that can automatically adjust the clock phase, video display position, and display shape of an optimal analog-digital converter.
[0013]
(Embodiment 1)
Hereinafter, embodiments of the first, third, and fourth aspects of the present invention will be described with reference to FIG.
[0014]
In FIG. 1, the video signal output from the computer and the analog video signal input from the video signal input 4 are input to the amplitude control device 8.
The analog video signal input to the amplitude control device 8 is amplified in voltage by the amplitude control signal 11 from the microcomputer 10 and input to the analog-digital conversion device 12 to be converted into a digital video signal.
Here, when the automatic adjustment device of the present invention is operated, the voltage amplitude correction in the amplitude adjustment device 11 is overcorrected, and when the automatic adjustment device of the present invention is not operated, an appropriate voltage amplitude is set.
[0015]
The clock control device 13 can control the frequency and phase of the clock to be transmitted based on the horizontal synchronization signal from the horizontal synchronization signal input 6 under the control of the microcomputer 10.
Analog-to-digital conversion is performed using the clock generated by the clock controller 13.
The number of MSBs of the video signal input to the signal processor 17 is counted by the microcomputer 10 for the digital video signal generated by the analog-digital converter 12 and the number is set to N1.
[0016]
Next, the clock control unit 13 changes the clock phase, counts the number of MSBs of the video signal input by the signal processing unit 17, reads it by the microcomputer 10, and sets the number to N2.
This operation is repeated n times for the number of clock phases that can be set by the clock controller 13. Since the analog video signal output from the computer is generated from the video display clock in the computer, it is a discontinuous signal in which display dots are synchronized. For this reason, if analog-to-digital conversion is not performed with a clock having the same phase as the video display clock in the computer, it is impossible to perform analog-to-digital conversion on a faithful computer image.
[0017]
This shift in clock phase is reflected in the phase of the clock used for analog-digital conversion and the number of MSBs of the digital signal.
That is, the point at which the change amount of the MSB of the signal with respect to the clock phase is measured and the change amount is minimized can be said to be the optimum point of the clock phase.
Here, the number N1, N2 of the MSB of the input signal read by the microcomputer 10, ..., the change amount of Nn from Nn An = | N n -N ( n-1) | points calculated An is minimized The clock phase corresponding to Aa is set as the optimum clock phase.
[0018]
Further, the signal processor 17 measures the number of clocks Hc from the timing at which the horizontal synchronizing signal input to the signal processor 17 is input to the time when the MSB of the digital video signal is first input, and takes it into the microcomputer 10.
The microcomputer 10 varies the output of the signal processing device 17 so that the signal is taken into the memory 21 of the signal processing device 17 from the timing delayed by Hc from the horizontal synchronizing signal.
[0019]
Similarly, the horizontal synchronizing signal Vc from the timing when the vertical synchronizing signal input to the signal processing device 17 is input to the time when the MSB of the digital video signal is first input is measured by the signal processing device 17 and is taken into the microcomputer 10.
The microcomputer 10 changes the output of the signal processing device 17 so as to be taken into the memory 21 of the signal processing device 17 from the timing delayed by Vc from the horizontal synchronizing signal.
[0020]
Further, the value obtained by measuring the number of clocks from the timing at which the MSB of the digital video signal input to the signal processing device 17 is first input between the horizontal synchronization signals to the timing at which the MSB is input last is the signal processing device 17. The horizontal resolution is obtained, and the digital video output from the memory 21 is varied based on this value.
[0021]
Similarly, the signal processing device 17 measures the number of horizontal synchronization signals from the timing when the MSB of the digital video signal input to the signal processing device 17 is first input between the vertical synchronization signals to the timing when the MSB is finally input. The obtained value becomes the vertical resolution, and the digital video output from the memory 21 is varied based on this value.
[0022]
Through the above operation, the digital video signal stored in the memory 21 is output. Therefore, in the automatic adjustment device of the present invention, the amplitude amplitude control device 8 overcorrects the voltage amplitude of the video signal, so that the MSB detection after analog-digital conversion can be performed even with a small-signal video signal input. The display position and display shape can be automatically adjusted.
[0023]
(Embodiment 2)
Hereinafter, the embodiments of the invention described in claim 2 of the present invention will be described with reference to FIG.
[0024]
In FIG. 2, by adopting a configuration such as a video projector 3 equipped with the automatic adjustment device 1 according to claim 1 , MSB detection after analog-digital conversion can be performed even with a small-signal video signal input as in the first embodiment. Therefore, the video projector can automatically adjust the clock phase, the display position of the video, and the display shape.
[0025]
【The invention's effect】
As described above, according to the automatic adjustment device and the video projector of the present invention, even if the video signal of the personal computer is input as a small signal, the digital signal is over-corrected by the analog-digital conversion device. Automatic adjustment device and video that can adjust the clock phase of the optimal analog-to-digital converter and adjust the display control device to the optimal video display position and display shape by adjusting the clock phase of the optimal analog-to-digital converter so that the MSB of the image can be accurately counted A projector can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram of an automatic adjustment apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram of a video projector according to a second embodiment of the present invention.
1 automatic adjustment device 3 video projector 4 video signal input 5 vertical synchronization signal input 6 horizontal synchronization signal input 7 analog video signal line 1
8 Amplitude controller 9 Analog video signal line 2
DESCRIPTION OF SYMBOLS 10 Microcomputer 11 Amplitude adjustment signal line 12 Analog-digital conversion apparatus 13 Clock control apparatus 14 Clock control signal line 15 Digital video signal line 1
16 clock signal line 17 signal processing device 18 reading signal line 19 signal processing device control line 20 digital video signal line 2
21 Memory 22 Digital video output line

Claims (2)

A microcomputer,
An amplitude control device that receives an analog video signal 1 output from a computer and is controlled in amplitude by an amplitude adjustment signal from the microcomputer;
An analog-to-digital converter that inputs the analog video signal 2 output of the amplitude control device and performs analog-to-digital conversion;
A clock control device that performs analog-to-digital conversion and controls the frequency and phase of a clock that is oscillated by the control of the microcomputer with reference to a horizontal synchronization signal;
A function 1 for inputting the digital video signal 1 produced by the analog-digital converter and counting the number of MSBs;
A function 2 for measuring the number of clocks Hc from when the horizontal synchronizing signal is input to when the MSB of the digital video signal 1 is first input;
A function 3 for measuring the horizontal synchronization signal Vc from the timing at which the vertical synchronization signal is input until the one MSB of the digital video signal is first input;
A function 4 for measuring the number of clocks from the timing at which the MSB of the digital video signal 1 is first input between horizontal synchronization signals to the timing at which the MSB is finally input;
A function 5 for measuring the number of horizontal synchronization signals from the timing at which the MSB of the digital video signal 1 is first input between the vertical synchronization signals to the timing at which the MSB is finally input, and is controlled by the microcomputer A signal processing device that outputs the digital video signal 2 by changing the digital video signal 1 converted from analog to digital based on the measured value;
A memory for taking in the output of the digital video signal 2 varied by the control of the microcomputer and the signal processing device;
With
When operating the automatic adjustment device,
The voltage amplitude correction in the amplitude adjustment device is overcorrected,
The number Nn of MSBs measured in the signal processing device is measured a plurality of times, the change amount An = | N n −N (n−1) | is calculated, and the clock phase at which An becomes the minimum is optimized. Control the phase of the clock to oscillate under the control of the microcomputer as the correct clock phase,
An automatic adjustment device, wherein the digital video output from the memory is varied based on the horizontal resolution calculated by the function 4 of the signal processing device and the vertical resolution calculated by the function 5.   A video projector comprising the automatic adjustment device according to claim 1.

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