JPH05158451A - Three wire color monitoring device - Google Patents

Abstract

PURPOSE:To provide a three wire color monitoring device which displays display data by scanning a beam with a scanning frequency corresponding to a picture size or the location of the picture even though the device is a three wire type. CONSTITUTION:A setting section 13 of a CRT control unit C outputs three output signals at least one of which is the combination of a composite synchronization signal and a reference level signal based on the setting, a color synchronization signal synthesizing section 7 synthesizes the three output signals and R, G, and B signals and outputs the result to the monitor side D as three composite signals through three wires, a scanning frequency selecting circuit section 25 of the monitor side detects setting conditions based on the composite synchronization signals contained in the composite signals inputted through the three wires and an oscillating circuit 33 outputs oscillating signals of scanning frequency corresponding to the detection result to a deflection circuit 34 so that seven kinds of different picture sizes or positions are obtained on a CRT 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-wire type monitor device, and more particularly to a three-wire type monitor device capable of changing the display screen size or display position of the monitor.

[0002]

2. Description of the Related Art Generally, a CRT control unit and a color CR
A red video signal, a green video signal, a blue video signal, a vertical synchronizing signal, as an interface signal required between the T monitor sections,
There are five types of horizontal sync signals.

As a method of interfacing these five kinds of signals, a five-wire system in which each of them independently interfaces with five signal lines, and a vertical sync signal and a horizontal sync signal are combined as a composite sync signal to form one signal line. A four-wire system that interfaces with a total of four signal lines.

Further, at least a composite sync signal composed of a vertical sync signal and a horizontal sync signal having a negative polarity and a green video signal (hereinafter referred to as B signal) are sync-on.
Combined as a Green signal and combined into one signal line,
There is a three-wire system that interfaces with a total of three signal lines. Three
The wire system is useful when it is desired to minimize the signal lines of the interface.

As for the scanning frequency of the CRT monitor, most of them are the single scanning type which can operate only at a single scanning frequency, but recently, for example, the vertical scanning frequency is 50Hz-100Hz and the horizontal scanning frequency is 30KHz-6.
A multi-scan type that can operate in the range of 5 KHz is being used.

[0006] Such a multi-scan type CRT
When 3 is used in a 3-wire system, a 4-wire system, or a 5-wire system, the deflection circuit of the multi-scan type CRT can automatically follow the scanning frequency, but the screen size and the screen position change depending on the scanning frequency. The user adjusts the scanning frequency adjuster provided in the multi-scan type CRT in advance, and the vertical screen size, vertical screen position, horizontal screen size,
The horizontal screen position was adjusted to an appropriate position.

In addition to the manual adjustment, the CRT monitor section equipped with an expensive automatic scan frequency setting device converts the high and low of the scan frequency into a DC voltage, and automatically adjusts the scan frequency according to the voltage level. It is also performed to identify and automatically set the optimum screen size and screen position for each scanning frequency.

However, since such an automatic scanning frequency setting device generally has a resolution of about 3 KHz, the scanning frequency can be identified every 3 KHz, but the scanning frequency during that period cannot be identified.

Therefore, in the 5-wire system, since the vertical synchronizing signal and the horizontal synchronizing signal are independently transmitted from the RGB converting section of the disk, four types of combinations are provided if the polarities of the vertical synchronizing signal and the horizontal synchronizing signal change. VGA, which is a display interface of an IBM personal computer, for example,
In a CRT monitor device or the like that can be connected to (Video Graphics Array), a vertical frequency and a horizontal frequency corresponding to the polarities of the vertical synchronizing signal and the horizontal synchronizing signal as shown in Table 1 are previously stored in the scanning frequency detecting unit of the CRT monitoring unit. It corresponds and is memorized.

[0010]

[Table 1] Then, depending on the scanning frequency of the CRT control unit, the polarities of the vertical synchronizing signal and the horizontal synchronizing signal are changed and sent to the CRT monitor unit, and the scanning frequency detecting unit changes the polarities of the input vertical synchronizing signal and horizontal synchronizing signal to 4 By identifying which one of the combination of types (positive / positive, positive / negative, negative / positive, negative / negative), four types of scanning modes can be identified without directly identifying the scanning frequency. It was

However, in the 3-wire type CRT monitor, the vertical synchronizing signal and the horizontal synchronizing signal are both combined into a B signal with a negative polarity and transmitted from the CRT control unit as described above, so that the scanning frequency detecting section is used. Then, only one combination can be identified, and as a result, it is meaningless to use the above-mentioned 5-wire scanning frequency detecting section.

Therefore, as described above, in the three-wire system, the user adjusts the scanning frequency adjuster provided in the multi-scan type CRT in advance to set the vertical screen size, vertical screen position, and horizontal screen. The size and horizontal screen position are adjusted to appropriate positions, or the CRT monitor unit is provided with an expensive automatic scanning frequency setting device having a resolution of about 3 KHz.

[0013]

Since the 3-wire type color monitor device as described above synthesizes the composite synchronizing signal with the B signal and transmits the composite signal, four types of vertical signals like the 5-wire type are used. Since the combination of the sync signal and the horizontal sync signal is not possible, the user has to manually adjust the scanning frequency adjuster provided in the multi-scan type CRT in advance when changing the screen size and the screen position. There was a problem.

Further, when the automatic scanning frequency adjuster is provided, the cost is high and the resolution is preset so that the scanning frequency of the resolution can be identified, but the scanning frequency exceeding the resolution cannot be identified. There was a problem.

Further, the vertical scanning frequency is 50 Hz to 100
Even a multi-scan type CRT that scans in the range of 30 Hz and a horizontal scanning frequency of 30 KHz to 65 KHz,
Since the 3-wire system is designed to transmit the composite sync signal combined with the B signal, only one set of scanning frequencies can be detected, and as a result, even if the composite sync signal is changed by the RGB converter of the disc, it is also compatible. Multi-scan CR with scanning frequency
There was a problem that T could not be controlled.

The present invention has been made to solve the above problems, and even with a three-line system, display data can be displayed by scanning a beam at a scanning frequency according to the screen size or screen position. It is an object to obtain a 3-wire type color monitor device.

[0017]

A three-wire type monitor device according to the present invention has a CRT control unit and a color monitor controlled by the CRT control unit,
The RT control unit inputs a composite sync signal and a reference level signal of a potential of a reference level of the composite sync signal, and at least one of a combination of these input signals outputs three output signals converted into the composite sync signal. A setting unit that is set to be output, three output signals from the setting unit, and R, G, and B signals of the three primary color components of display data are combined and output as three composite signals via three lines. And a color / synchronization signal synthesizing circuit section.

Then, the color monitor detects the setting state of the setting section based on the composite synchronizing signal contained in the three composite image signals input via the three lines, and selects the scanning frequency based on the detection result. And a scanning frequency selection circuit section for outputting a selection signal to be output, and an oscillation circuit for outputting an oscillation signal having a scanning frequency corresponding to a combination of the selection signals to the deflection circuit of the color monitor.

[0019]

In the present invention, at least one of the combination of the composite sync signal and the reference level signal of the potential of the reference level of the composite sync signal is set to the composite sync signal based on the setting. The output three output signals are output.

Next, the color / synchronization signal synthesizing circuit unit synthesizes the three output signals and the R, G, B signals and outputs the three composite signals to the monitor side via the three lines.

The scanning frequency selection circuit unit on the monitor side detects the setting state based on the composite synchronizing signal contained in the three composite signals, and outputs the selection signal corresponding to the detection result.

Then, the oscillation circuit outputs an oscillation signal of a scanning frequency corresponding to the combination of the selection signals to the deflection circuit of the color monitor, and the beam scans the display portion of the color monitor based on the scanning frequency.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic block diagram of a three-wire type color monitor device of the present invention. In the figure, reference numeral 1 denotes a color signal output unit for 3-wire CRT control (also referred to as an interface unit). The R signal output circuit 2 of the color signal output unit 1 extracts only the red component from the display data stored in the video memory (not shown) and outputs it as an R signal, and the G signal output circuit 3 outputs the green signal from the display data. Only the component is extracted and output as a G signal, and the B signal output circuit 4 extracts only the blue component from the display data and outputs it.

Reference numeral 5 is a composite synchronizing signal output circuit. The composite sync signal output circuit 5 determines the vertical sync signal and the pixel position in the frame of the display screen for each frame of the display screen based on the reference level (hereinafter referred to as the pedestal level) of the composite color video signal (hereinafter referred to as the composite signal). By outputting the horizontal synchronizing signal, the R, G, and B signals that are output correspond to which position on the display screen. A reference level signal output circuit 6 outputs a pedestal level signal (0 V).

Reference numeral 7 is a color / synchronization signal synthesizing unit. The R sync signal synthesizing circuit 8 of the color / sync signal synthesizing unit 7 inputs the R signal, synthesizes an output signal from a first selector, which will be described later, into an R signal input as a complex synchronizing signal, and corresponds as an R composite signal. Output to the RGB terminal 11, and the G synchronizing signal synthesizing circuit 9 inputs the G signal, and the output signal from the second selector, which will be described later, is used as the composite synchronizing signal and the input G signal is input.
RG that is synthesized into a signal and corresponds as a G composite signal
The signal is output to the B terminal 11, and further the B sync signal synthesis circuit 10
Inputs the B signal, uses the output signal from the third selector, which will be described later, as a composite synchronizing signal, and synthesizes it with the input B signal.
It outputs to the corresponding RGB terminal 11 as a composite signal.

Reference numeral 13 is a setting unit. The setting unit 13 is R,
A first selector 14, a second selector 15, and a third selector 16 are provided corresponding to the G and B signals, respectively, and a composite synchronizing signal output circuit 5 and a reference level signal output circuit 6 are provided, respectively.
The input terminals are connected to each other to output one output signal respectively, and based on the setting, any one of the three output signals is set as a composite synchronizing signal, and the setting is switched so that the three output signals are Be taken to the street.

Reference numeral 20 is an RGB terminal on the monitor side, and 21 is a composite signal receiving section. The composite signal receiving / receiving unit 21 has an R signal amplifying circuit 22, a G signal amplifying circuit 23, and a B signal amplifying circuit 24, and amplifies and outputs each.

Reference numeral 25 is a scanning frequency selection circuit section. In the scanning frequency selection circuit unit 25, the R signal / synchronization signal separation circuit 27 of the color / synchronization signal separation circuit unit 26 separates the R signal and the frequency component of the composite synchronization signal from the R composite signal of the composite signal reception unit 21, The G signal / sync signal separating circuit 28 separates the G signal and the frequency component of the composite sync signal from the G composite signal from the composite signal receiving section 21 and outputs the G composite signal as the G composite sync signal. Further, a B signal / synchronization signal separation circuit 29
Separates the frequency component of the B signal and its composite synchronizing signal from the B composite signal from the composite signal receiving section 21 and outputs it as the B composite synchronizing signal.

Next, in the OR circuit 30 of the scanning frequency selection circuit unit 25, the color / synchronization signal separation circuit unit 26 logically ORs the frequency component signals of the three composite synchronization signals, and performs the composite synchronization with the frequency component signals. If the signal is included, the composite sync signal is output.

Next, the vertical / horizontal sync separation circuit 31 is ORed.
The vertical sync signal and the horizontal sync signal are separated from the composite sync signal from the circuit 30 and output.

A combination in which the scanning mode detecting circuit 32 selects in advance seven horizontal synchronizing scanning frequencies and vertical synchronizing scanning frequencies (hereinafter collectively referred to as scanning frequencies) corresponding to combinations of three horizontal synchronizing signals. The selection signal of is output.

Next, the oscillation circuit 33 changes the vertical deflection frequency and the horizontal deflection frequency of the deflection circuit 34 based on the selection signal from the scanning mode detection circuit 32, and scans the beam emitted to the CRT 35 at the scanning frequency. To determine the screen size or screen position. FIG. 2 is a three-wire CR of the present invention.
It is a wave form diagram explaining operation | movement of T control unit part. In this case, the case where the first selector 14 and the third selector 16 are switched to the composite synchronizing circuit 5 side will be described.

In the figure, a is a composite synchronizing signal, b is a reference level signal, c is an R signal, d is a G signal, e is a B signal,
c is an R composite sync signal, d is a G signal, e is a B signal, and f is R
A composite signal, h is a G composite signal, i is a B composite signal, 41 is a vertical synchronizing signal, and 42 is a horizontal synchronizing signal.

For example, when the first select 14 and the third selector are switched to the composite sync signal and the second selector 15 is switched to the signal of the reference level, the R sync signal of the color / sync signal synthesizing circuit 7 is switched. The synthesizing circuit 8 uses the output signal from the first selector 14 as the composite synchronizing signal a and the R signal c.
And RG as the R composite signal f shown in FIG.
Output to B terminal 11.

Further, the G sync signal synthesizing circuit 9 outputs the G signal d.
The output signal from the second selector 15 and the output signal from the second selector 15 are combined as a composite synchronizing signal. However, since the second selector 14 is switched in the reference level signal output circuit 6, the output signal is the signal of the reference level shown in FIG. b, and outputs the G composite signal h in which the original composite sync signal is not synthesized as shown in FIG.

Further, the B synchronizing signal synthesizing circuit 10 synthesizes the B signal e and the composite synchronizing signal a which is the output signal from the third selector 16 and outputs it as the B composite signal i. In this way, by switching the settings of the first selector 14 to the third selector 16, the form of the three composite signals in which the composite synchronizing signal a is combined with any of R, G, and B is changed to seven types. This makes it possible to easily determine the scanning frequency if the monitor can detect these seven forms.

FIG. 3 is a schematic block diagram showing an embodiment of the scanning mode detecting circuit. In the figure, a delay circuit 45 delays the vertical sync signal from the vertical / horizontal sync separation circuit 31 for a predetermined period. The first D flip-flop 46 outputs the R signal
Input the R composite sync signal from the sync signal separation circuit 27,
When the vertical sync signal is input from the delay circuit 45 and the vertical sync signal is included in the input R composite sync signal, the output is set to logic "1". The second D flip-flop 47 receives the G composite sync signal from the G signal / sync signal separation circuit 28, and along with the input of the vertical sync signal from the delay circuit 45, the input G composite sync signal is converted into the vertical sync signal. Is included, the output is set to logic "1".

The third D flip-flop 48 outputs the B signal
Input the B composite sync signal from the sync signal separation circuit 29,
When the vertical synchronization signal is input from the delay circuit 45 and the vertical synchronization signal is included in the input B composite synchronization signal, the output is set to logic "1".

3-8 decoder 49 (hereinafter referred to as DEC)
Is a logic "1" or a logic "0" 7 input from the first D flip-flop 46 to the third D flip-flop 49.
The selection signals of seven combinations corresponding to the different combinations are output to the scanning frequency setting circuit 33.

FIG. 4 is a waveform diagram for explaining the operation on the monitor side of the present invention. For example, when the first selector 14 and the third selector 16 are switched to the composite synchronizing signal output circuit 5, the horizontal synchronizing signal 41 and the vertical synchronizing signal are fed from the R signal / synchronizing signal separating circuit 27 as shown in FIG. The R composite sync signal k including the signal 42 is output.

The B signal / synchronization signal separation circuit 28 outputs the G composite synchronization signal m at the reference level (0 V). The B signal / sync signal separation circuit 29 outputs a B composite sync signal n including a horizontal sync signal 41 and a vertical sync signal 42.

Next, the OR circuit 30 outputs the R composite synchronizing signal k,
The G composite sync signal m and the B composite sync signal n are input and logically ORed, and only the composite sync signal is output to the vertical / horizontal sync separation circuit 31. That is, the OR circuit 30 detects whether the composite synchronizing signal is included.

Next, the vertical / horizontal sync separation circuit 31 is shown in FIG.
The vertical sync signal and the horizontal sync signal p are separated from the composite sync signal and output to the scanning mode detection selection circuit 32 as shown in FIG.

Since the scanning mode detecting circuit 32 is constructed as shown in FIG. 3, the delay circuit 45 delays the vertical synchronizing signal p from the vertical / horizontal synchronizing separating circuit 31 for a predetermined period to delay the first D flip-flop. To the third D flip-flop 48.

First D flip-flop 46 to third D
The flip-flop 48 outputs a logic "1" when the R composite sync signal k includes the vertical sync signal p at the rising edge of the vertical signal p, and outputs a logic "0" when it does not.

In this case, since the R composite synchronizing signal k and the B composite synchronizing signal n include the vertical synchronizing signal p, the logic is set to 1010000.

That is, the setting state of the setting unit 13 is detected by outputting the logic of the scanning mode corresponding to the first selector 14 to the third selector 16.

Next, the DEC 49 inputs the logic 1010.
One of the output terminals is set to logic "1" based on the combination of 000. That is, as shown in Table 1, R signal, G
The outputs of the scanning modes of 1 to 7 corresponding to the combination of the signal and the vertical synchronizing signal combined with the B signal in the vertical synchronizing signal are obtained as the selection signals.

[0049]

[Table 2] Next, the oscillation output circuit 33 sets the circuit constants so that there are seven oscillation signals of the corresponding scanning frequency in the scanning modes 1 to 7, and the deflection circuit 34 sets the horizontal scanning frequency of the oscillation signal of the scanning frequency. Since the beam is scanned at the vertical scanning frequency, it is possible to obtain the screen size or screen position according to the setting state.

Therefore, also in the 3-line multi-scan monitor, it is possible to provide the multi-scan monitor in which the optimum screen size and screen position can be obtained by identifying the scanning mode, like the 5-line multi-scan monitor.

Further, since the scanning frequency is selected in accordance with this selection signal, it is possible to oscillate even at scanning frequencies close to each other.

[0052]

As described above, according to the present invention, in the CRT control unit, at least one of the three output signals of the combination of the composite synchronizing signal and the reference level signal and the R, G, B signals based on the setting is provided. The combined result is output as 3 composite signals to the monitor side via 3 lines, and the monitor side detects the setting condition based on the composite sync signal contained in the composite signal input via 3 lines, and the detection result By outputting the oscillation signal of the scanning frequency corresponding to the above to the deflection circuit, the scanning frequency becomes 7 kinds, so that 7 kinds of screen sizes or screen positions can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a three-wire color monitor device of the present invention.

FIG. 2 is a waveform diagram illustrating the operation of the 3-wire CRT control unit unit of the present invention.

FIG. 3 is a schematic configuration diagram showing an embodiment of a scan mode detection circuit.

FIG. 4 is a waveform diagram illustrating an operation on the monitor side of the present invention.

[Explanation of symbols]

 1 color signal output unit 2 R signal output circuit 3 G signal output circuit 4 B signal output circuit 5 composite synchronizing signal output circuit 7 color / synchronizing signal synthesizing unit 13 setting unit 21 composite signal receiving unit 25 scanning frequency selecting circuit unit 26 period signal Separation circuit section 32 Scan mode detection circuit 33 Oscillation circuit 34 Deflection circuit

Claims (1)

[Claims] 1. A CRT control unit and a color monitor controlled by the CRT control unit, wherein the CRT control unit inputs a composite sync signal and a reference level signal of a potential of a reference level of the composite sync signal. However, at least one of the combinations of these input signals has been converted into the composite synchronization signal.
A setting unit that is set to output one output signal, three output signals from the setting unit, and R, G, and B signals of the three primary color components of display data are combined, and three lines are formed as three composite signals. And a color / synchronization signal synthesizing circuit section for outputting via the three lines, the color monitor of the setting section based on the composite synchronization signals included in the three composite image signals input via the three lines. A scanning frequency selection circuit unit that detects a setting state and outputs a selection signal that selects a scanning frequency based on the detection result, and an oscillation signal of a scanning frequency that corresponds to the combination of the selection signals is deflected by the color monitor. A three-wire color monitor device having an oscillating circuit for outputting to a circuit.