JPH1069254A - Display control device and display device - Google Patents

Abstract

(57) [Problem] To provide a liquid crystal display device capable of normal display by automatically determining various synchronization signal systems and optimizing each synchronization signal system to a liquid crystal module. A central processing circuit (111) includes a vertical synchronization signal (102).
And the composite vertical synchronization signal 104 output from the synchronization separation circuit 110 and the SOG vertical synchronization signal 106 output from the synchronization separation circuit 110 are monitored. And each signal 102,
The selectors 112 and 113 are switched by changing the content of the selection signal 107 according to the presence or absence of 104 and 106. If there are a plurality of signals, one is selected according to a predetermined priority (separate mode> composite mode> SOG mode). As a result, the synchronization signal input at that time is transmitted to the control signal generation circuit through the selectors 112 and 113.
Output to 114. The control signal generation circuit 114 outputs a control signal 115 optimized for the liquid crystal module 116 to the liquid crystal module 116 to cause a normal display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device for displaying on a liquid crystal display, and more particularly to a liquid crystal display device with a CRT interface.

[0002]

2. Description of the Related Art Currently, there are a horizontal synchronizing signal and a vertical synchronizing signal as a synchronizing signal outputted from an information processing apparatus such as a personal computer to a display device. These two synchronizing signals are transmitted in a separate synchronizing signal system, a composite synchronizing signal system, and a sync-on-green (hereinafter "SOG") method.
A synchronous signal method). The separate synchronization signal method is a method of outputting these two synchronization signals to a display device using separate signal lines. The composite synchronization signal method is a method in which two synchronization signals are superimposed and superimposed on one signal line (for example, a horizontal synchronization signal line) and output to a display device. The SOG synchronizing signal system is a kind of a composite synchronizing signal system, in particular, a system in which a synchronizing signal is superimposed on a green signal and output to a display device.

In recent years, liquid crystal display devices characterized by space saving and low power consumption have appeared as display devices instead of general CRTs, and some of them have the same input interface as the CRT. .

FIG. 10 shows a configuration of a conventional CRT interface liquid crystal display device. In FIG. 10, reference numeral “10”
Similarly, the horizontal synchronization signal is denoted by “1.” Similarly, reference numeral “102” denotes a vertical synchronization signal, “103” denotes a green signal, “104” denotes a composite vertical synchronization signal, and “10” denotes a composite vertical synchronization signal.
5 is an SOG horizontal synchronization signal, "106" is an SOG vertical synchronization signal, "107" is a selection signal, "108" is a selected horizontal synchronization signal, "109" is a selected vertical synchronization signal, and "109" is a selected vertical synchronization signal. Reference numeral 110 denotes a synchronization separation circuit, reference numeral 112 denotes a horizontal synchronization signal selector, reference numeral 113 denotes a vertical synchronization signal selector, reference numeral 114 denotes a liquid crystal module control signal generation circuit, and reference numeral 115 denotes a liquid crystal module control signal. To "11
"6" indicates a liquid crystal module, and "301" indicates a manual switch.

When an information processing device (not shown) for outputting a separate synchronization signal is connected to the liquid crystal display device, the switch 301 is set to a state where the separate synchronization signal side is selected. The horizontal synchronizing signal selector 112 and the vertical synchronizing signal selector 113 enter a selection state according to the selection signal 107 input from the switch 301. That is, in this case, the horizontal synchronizing signal selector 112 and the vertical synchronizing signal selector 113 select the horizontal synchronizing signal 101 and the vertical synchronizing signal 102 sent from the information processing device, and transmit them to the liquid crystal module control signal generating circuit 114. To supply. The liquid crystal module control signal generation circuit 114
The liquid crystal module 11 is obtained from the horizontal synchronization signal 108 for the liquid crystal module and the vertical synchronization signal 109 for the liquid crystal module.
A liquid crystal module control signal 115 optimized for 6 is generated and output.

When an information processing device (not shown) for outputting a composite synchronization signal is connected to a liquid crystal display device, the switch 301 is set to a state where the composite synchronization signal side is selected. Thereby, the selector 11
Reference numerals 2 and 113 indicate that the horizontal synchronization signal 101 and the composite vertical synchronization signal 104 have been selected. The synchronization separation circuit 110 separates the composite vertical synchronization signal 104 from the composite synchronization signal (here, the horizontal synchronization signal 101) sent from the information processing apparatus, and
To the control signal generation circuit 114 for the liquid crystal module. The horizontal synchronizing signal 101 is also transmitted through the selector 112 to the liquid crystal module control signal
14. The liquid crystal module control signal generation circuit 114 generates and outputs a liquid crystal module control signal 115 based on these.

Further, when an information processing device (not shown) for outputting an SOG synchronization signal is connected to the liquid crystal display device, the switch 301 is set to a state where the SOG synchronization signal side is selected. As a result, the selectors 112 and 113
The OG horizontal synchronizing signal 105 and the SOG vertical synchronizing signal 106 are selected. The green signal 102 sent from the information processing device is supplied to the sync separation circuit 103. The sync separation circuit 110 converts the SOG horizontal sync signal 105 and the SOG vertical sync signal 106 from the green signal 102.
And is extracted separately. Then, these are connected to the selector 112,
113, a liquid crystal module synchronization generation circuit 114
To supply. Liquid crystal module control signal generation circuit 114
Is based on the control signals 115 for the liquid crystal module.
Is generated and output.

[0008]

However, in the above prior art, the information processing device that outputs a separate synchronization signal and the information processing device that outputs a composite synchronization signal
Each time the information processing device that outputs the OG synchronization signal is replaced, the user must manually operate the switch 301, which is troublesome.

Further, some information processing apparatuses use different synchronization signal systems (separate synchronization signal, composite synchronization signal, SOG synchronization signal) for each display mode. When such an information processing device is connected, the method of the synchronization signal is also switched with the change of the display mode, and there is a problem that a normal display is not performed as it is.

An object of the present invention is to identify a type of a synchronization signal (separate synchronization signal, composite synchronization signal, SOG synchronization signal) input at that time and to automatically switch a processing method of the synchronization signal. A device and a display control device are provided.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and a first aspect of the invention is to provide a display device based on a signal including a synchronization signal input from the outside. In a display control device that generates a control signal to be controlled, a plurality of input signal lines to which a signal including the synchronization signal is input, and a method of the synchronization signal input at that time is one of a predetermined method. Determination means for determining whether the input signal line is the input signal line to which the synchronization signal is input at that time based on the determination result of the determination means, and selecting the synchronization signal transmitted through the input signal line There is provided a display control device, comprising: a selector to be output; and a control signal generation circuit that generates a control signal based on a synchronization signal output from the selector.

A horizontal synchronizing signal and / or a vertical synchronizing signal are extracted from an original signal on which a vertical synchronizing signal and / or a horizontal synchronizing signal are superimposed, and the extracted horizontal synchronizing signal and / or vertical synchronizing signal are replaced with the original signal. It is preferable to provide a separating means for outputting the signal to the input signal line which is determined in advance according to the type.

[0013] As the above-mentioned predetermined system, a separate system in which the horizontal synchronizing signal and the vertical synchronizing signal are conveyed as independent signals, and a composite system in which the horizontal synchronizing signal and the vertical synchronizing signal are superimposed and conveyed as one signal It may include at least two of an SOG method and a SOG method in which a horizontal synchronizing signal and a vertical synchronizing signal are superimposed on a green signal of a video signal and conveyed as one signal.

The determination means may make the determination based on the presence or absence of a vertical synchronization signal for each of the predetermined methods.

[0015] A predetermined priority order is provided among the synchronization signal systems. If a plurality of synchronization signals are detected as a result of the determination by the determination means, the detected system is determined according to the priority order. Preferably, there is provided a selecting means for selecting any one of the above, and the selector selects and outputs a synchronization signal of the system selected by the selecting means.

As the above-mentioned predetermined system, a separate system in which the horizontal synchronizing signal and the vertical synchronizing signal are carried as independent signals, and a composite system in which the horizontal synchronizing signal and the vertical synchronizing signal are superimposed and carried as one signal And a SOG system in which a horizontal synchronizing signal and a vertical synchronizing signal are superimposed on a green signal of a video signal and conveyed as one signal, wherein the priority order is a separate system> composite Method>
It is preferable that the order is the SOG method.

According to a second aspect of the present invention, there is provided a display control device for generating a control signal for controlling a display device based on an externally input signal, wherein a plurality of signals to which a signal including a synchronization signal is input are provided. An input signal line, for a predetermined one of the input signal lines, a determination unit for determining whether or not a synchronization signal is actually input at that time; and the synchronization signal is input at that time among the input signal lines. Is selected based on the determination result of the determination means,
A display control device comprising: a selector that outputs a synchronization signal transmitted through the input signal line; and a control signal generation circuit that generates a control signal based on the synchronization signal output by the selector. Is done.

The determination means determines whether or not a vertical synchronization signal is actually input to the input signal line of the input signal line to which a vertical synchronization signal is input at that time. Is preferred.

The determination means includes a counting circuit for counting the number of pulses input to the predetermined input signal line at that time, and a predetermined value. The counting result of the counting circuit and the predetermined value are set. It may include a comparison circuit that compares the value and a selection signal generation circuit that generates a selection signal for controlling the selector based on a comparison result of the comparison circuit.

An original signal in which at least two of a horizontal synchronizing signal, a vertical synchronizing signal, and a video signal are superimposed is input, and a horizontal synchronizing signal and / or a vertical synchronizing signal are separated from the original signal. It is preferable to further include a separating unit that outputs the separated horizontal synchronizing signal and / or vertical synchronizing signal to an input signal line predetermined in accordance with the original signal of the horizontal synchronizing signal and / or the vertical synchronizing signal.

In the above-mentioned input signal line, a priority set between input signal lines to which a vertical synchronizing signal is input is provided, and when the judging means detects a synchronizing signal on a plurality of input signal lines, the priority is set. It is preferable that a selector is provided to select any one of the input signal lines based on the input signal line, and the selector outputs the synchronization signal transmitted through the selected input signal line to the selector.

According to a third aspect of the present invention, there is provided a display control device according to the first or second aspect, and a liquid crystal module for displaying an image based on the control signal and image data input separately. A display device characterized by having a display device is provided.

The operation of the first and third embodiments will be described.

The separating means extracts a horizontal synchronizing signal and / or a vertical synchronizing signal from the original signal. Then, the extracted horizontal synchronizing signal and / or vertical synchronizing signal are output to an input signal line predetermined according to the type of the original signal.

The determining means determines whether the type of the synchronization signal input at that time is one of a predetermined method (for example, a separate method, a composite method, and an SOG method). This determination can be made, for example, based on the presence or absence of a vertical synchronization signal in each system.

The selector selects the input signal line to which the synchronization signal is input at that time based on the result of the judgment by the judging means. Then, the synchronization signal transmitted through the input signal line is output.

When a plurality of types of synchronization signals are detected by the determination means, the priority determined in advance by the selection means (for example, a separate type>
Any one of the detected methods may be selected according to the composite method> SOG method. In this case, the selector selects and outputs a synchronization signal of the type selected by the selection means.

The display signal generation circuit generates a control signal based on the synchronization signal output from the selector. The liquid crystal module performs display based on the control signal.

The operation in the second and third aspects will be described.

The separating means separates a horizontal synchronizing signal and / or a vertical synchronizing signal from an original signal on which at least two of a horizontal synchronizing signal, a vertical synchronizing signal and a video signal are superimposed. And the separated horizontal synchronization signal and / or
Alternatively, a vertical synchronization signal is output to an input signal line predetermined according to the type of the original signal.

The determination means determines whether or not a synchronization signal is actually input at that time for a predetermined one of the input signal lines. For example, for an input signal line to which a vertical synchronization signal is input, it is determined whether or not a vertical synchronization signal is actually input to the input signal line at that time.

The selector selects the input signal line to which the synchronization signal is input at that time based on the result of the determination by the determination means. Then, the synchronization signal transmitted through the input signal line is output.

When the determination means detects a synchronization signal on a plurality of input signal lines, a selection means for selecting any one of the input signal lines based on a predetermined priority order may be provided. In this case, the above-described selector
The synchronizing signal sent through the selected input signal line is output to the selecting means.

The control signal generation circuit generates a control signal based on the synchronization signal output from the selector. The liquid crystal module performs display based on the control signal.

[0035]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[Embodiment 1] The liquid crystal display device of Embodiment 1 is characterized in that the type of the synchronization signal input at that time is automatically identified and can be responded to. However, the methods of the synchronization signal that can be automatically identified are only the separate method, the composite method, and the SOG method.

As shown in FIG. 1, the liquid crystal display device includes a synchronization separation circuit 110, a central processing circuit 111, a horizontal synchronization signal selector 112, a vertical synchronization signal selector 113, a liquid crystal module control signal generation circuit 114, and a liquid crystal module 116. Become.

The sync separation circuit 110 outputs the horizontal sync signal 10
1. A vertical synchronizing signal and a horizontal synchronizing signal are extracted and separated from the green signal 103. Specifically, a composite vertical synchronization signal 104 is extracted and separated from the horizontal synchronization signal 101. Also, from the green signal 103, SO
G horizontal sync signal 105 and SOG vertical sync signal 106
Is extracted and separated. Among the extracted and separated signals, the vertical synchronization signals (composite vertical synchronization signal 104 and SOG vertical synchronization signal 106) are output to the vertical synchronization signal selector 113. The composite horizontal synchronization signal 104 is output to the horizontal synchronization signal selector 112.

The sync separation circuit 110 always performs the above-described various sync signal extraction and separation processes on the horizontal sync signal 101 and the green signal 103 described above. Therefore, for example, when the separate system is adopted as the system of the synchronization signal, even if this extraction / separation process is performed on the horizontal synchronization signal 101, the "waveform" which is a composite vertical synchronization signal in a substantial sense "(Or" pulse ") are not extracted. However, the sync separation circuit 110
Output the composite vertical synchronization signal 104 which does not include the "waveform" even in this case. SO
G horizontal synchronization signal 104 and SOG vertical synchronization signal 106
The same applies to. As will be described later, in the present embodiment, the method of the synchronization signal input at that time is determined based on the presence or absence of the “waveform”.

The central processing circuit 111, the horizontal synchronizing signal selector 112 and the vertical synchronizing signal selector 113 determine the type of the currently input synchronizing signal, and determine the type of the currently input synchronizing signal based on the judgment result. This is output to the liquid crystal module control signal generation circuit 114.

The horizontal synchronizing signal selector 112 includes a horizontal synchronizing signal (horizontal synchronizing signal 101) of a separate system and a horizontal synchronizing signal (horizontal synchronizing signal 101) of a composite system.
And an SOG horizontal synchronization signal (SOG horizontal synchronization signal 1)
05) is input, and one of them is selected. The horizontal synchronization signal selector 112
Is the selected horizontal synchronizing signal and the selected horizontal synchronizing signal 10
8 is output to the liquid crystal module control signal generation circuit 114. Which synchronization signal is selected is determined based on the selection signal 107 input from the central processing circuit 111.

The vertical synchronizing signal selector 113 includes a vertical synchronizing signal of a separate system (vertical synchronizing signal 102), a vertical synchronizing signal of a composite system (composite vertical synchronizing signal 104), and a vertical synchronizing signal of an SOG system (SOG vertical synchronizing signal). 106) is input, and any one of them is selected. The vertical synchronization signal selector 113 outputs the selected vertical synchronization signal to the liquid crystal module control signal generation circuit 114 as the selected vertical synchronization signal 109. Which of the synchronization signals is selected is determined by the selection signal 107 input from the central processing circuit 111.
Has been determined based on

The central processing circuit 111 sequentially determines the type of the synchronization signal input at that time. Also,
The selection signal 107 is generated and output based on the determination result. The central processing circuit 111 includes a composite vertical synchronizing signal 104, a SOG vertical synchronizing signal
6 and the vertical synchronization signal 102 are input. The above-described determination of the method of the synchronization signal is based on these vertical synchronization signals 10.
This is performed by determining whether or not a substantial signal ("waveform") is detected for each of 2, 104, and 106.

Incidentally, some information processing apparatuses simultaneously transmit a plurality of types of synchronization signals. When such an information processing device is connected to the display device of the present embodiment,
In the above-described determination method, the presence of a plurality of types of synchronization signals is detected. In such a case, it is necessary to select a synchronization signal of any one of the synchronization signals whose existence has been confirmed. Therefore, in the present embodiment, in such a case, the selection is performed according to a predetermined priority. Specific priorities in the present embodiment are as follows.

Priority between synchronization signals: Separate synchronization signal> Composite synchronization signal>
SOG synchronization signal According to the priority, for example, a separate synchronization signal,
If the presence of the composite synchronization signal is confirmed at the same time, the central processing circuit 111 selects the separate synchronization signal.

The determination and priority order by the central processing circuit 111 will be described later in more detail with reference to FIG.

Liquid crystal module control signal generation circuit 114
Is for generating a liquid crystal module control signal 115 optimized for the liquid crystal module 116 based on the selected horizontal synchronization signal 108 and the selected vertical synchronization signal 109. The liquid crystal module control signal generation circuit 11
4 outputs the liquid crystal module control signal 115 to the liquid crystal module 116.

The liquid crystal module 116 operates according to the liquid crystal module control signal 115 to display separately input display data (not shown).

"Separation means" in the claims
Corresponds to the synchronization separation circuit 110. “Original signal”
Horizontal synchronization signal 101, green signal 103, vertical synchronization signal 1
02. The “input signal line” refers to the signal line 101,
102, 104, 105, and 106. The “determination unit” and the “selection unit” correspond to the central processing unit 111 or a determination circuit in a fifth embodiment described later.
The “selector” corresponds to the horizontal synchronization signal selector 112 and the vertical synchronization signal 113. The “display signal generation circuit” corresponds to the liquid crystal module training fish signal generation circuit 114. The “selection signal” corresponds to the selection signal 107.

An outline of the operation of the apparatus will be described.

The synchronization separation circuit 110 outputs the horizontal synchronization signal 10
1 is separated from the composite vertical synchronizing signal 104 by the central processing circuit 111 and the vertical synchronizing signal selector 11.
Output to 3. The SOG horizontal synchronizing signal 105 and the SOG vertical synchronizing signal 106 are extracted and separated from the green signal 103. Then, the SOG horizontal synchronization signal 105 is output to the horizontal synchronization signal selector 112. Also, SO
For the G vertical synchronization signal 106, the central processing circuit 111
And outputs it to the vertical synchronizing signal selector 113.

The central processing circuit 111 has a signal ("waveform" which is a synchronizing signal in a substantial sense) for each of the above-described composite vertical synchronizing signal 104, SOG vertical synchronizing signal 106 and vertical synchronizing signal 102. By determining whether or not the synchronization signal is input, the method of the synchronization signal input at that time is determined. If there are a plurality of types of synchronization signals, any one of the synchronization signals is selected in accordance with a predetermined priority. Then, a selection signal 107 corresponding to the determination and the selection result is output to the horizontal synchronization signal selector 112 and the vertical synchronization signal selector 113. The selection state of the horizontal synchronization signal selector 112 and the vertical synchronization signal selector 113 changes according to the selection signal 107. As a result, only the synchronization signal of the method selected at that time is the horizontal synchronization signal 108 for the liquid crystal module,
The signal is output to the liquid crystal module control signal generation circuit 114 as the liquid crystal module vertical synchronization signal 109. The liquid crystal module control signal generation circuit 114 generates a liquid crystal module control signal 115 optimized for the liquid crystal module 116 based on these, and outputs this to the liquid crystal module 116.

Next, the operation of determining and selecting a synchronization signal by the central processing circuit 111 will be described in more detail with reference to FIG.

The central processing circuit 111 internally has four states (“no synchronization signal input” 204, “separate synchronization signal selection” 201, “composite synchronization signal selection” 202,
“SOG synchronization signal selection” 203) is provided. Then, transition is made between the states according to the method of the synchronization signal input at that time. Further, as described above, when a plurality of types of synchronization signals are input, which state to transition to is determined according to the above-described priority.

When the power is turned on, the central processing circuit 111 always checks whether or not a vertical synchronizing signal of each system is input.

Initially, the central processing circuit 111 is in the state of "no synchronization signal input" 204.

When the presence of the separate vertical synchronizing signal 102 is detected in this state, the central processing circuit 111
It is determined that the method of the synchronization signal input at that time is the separate method. Therefore, the central processing circuit 111 shifts to the state of the separate synchronization signal selection 201 according to the determination result. Then, the selectors 112 and 113 are caused to select the synchronization signals 101 and 102.

In the state of "no sync signal input" 204, the presence of the composite vertical sync signal 104 is detected,
If the presence of the separate vertical synchronization signal 102 cannot be detected, the central processing circuit 111 determines that the system of the synchronization signal input at that time is the composite system. Therefore, according to the determination result, the central processing circuit 111
Moves to the state of “composite synchronization signal selection” 202. Then, the selectors 112 and 113 are caused to select the synchronization signals 101 and 104.

If the presence of the SOG vertical synchronization signal 106 is detected and the presence of the separate vertical synchronization signal 102 and the composite vertical synchronization signal 104 cannot be detected in the state of "no synchronization signal input" 204, the central processing circuit 111 Means that the type of the synchronization signal input at that time is S
It is determined that the OG method is used. Therefore, the central processing circuit 11
1 moves to the state of “SOG synchronization signal selection” 203. Then, the selector 112 and 113 supply the synchronization signal 1
05 and 106 are selected.

When the presence of the separate vertical sync signal 102 is detected in the state of “SOG sync signal selection” 203, the central processing circuit 111 moves to the state of “separate sync signal selection” 201. When the presence of the composite vertical synchronization signal 104 is detected, the central processing circuit 111 moves to “composite synchronization signal selection” 202. SO
When the presence of the G vertical synchronization signal 106 cannot be detected, the state shifts to the state of “no synchronization signal input” 204.

When the presence of the separate vertical synchronization signal 102 is detected in the state of “composite synchronization signal selection” 202, the central processing circuit 111 moves to “separate synchronization signal selection” 201. When the presence of the composite vertical synchronization signal 104 cannot be detected, the state shifts to the state of “no synchronization signal input” 204.

When the presence of the separate vertical synchronization signal 102 is detected in the state of "separate synchronization signal selection" 201, the central processing circuit 111 maintains the state. When the presence of the separate vertical synchronization signal 102 cannot be detected, the central processing circuit 111 moves to the state of “no synchronization signal input” 204.

As described above, according to the present embodiment, the system of the synchronization signal input at that time is automatically identified,
The liquid crystal module can be controlled.

In the first embodiment, the horizontal synchronizing signal 102 input from the outside is directly input to the horizontal synchronizing signal selector 112 as the composite horizontal synchronizing signal. However, when the vertical synchronization signal is superimposed on the horizontal synchronization signal 102, the horizontal synchronization signal selector 112
May not work properly. In such a case,
As a composite horizontal synchronizing signal, the horizontal synchronizing signal after the vertical synchronizing signal is separated by the sync separation circuit 110 is
An input is made instead of the horizontal synchronization signal 102.

In the first embodiment, by adopting the above-described priorities, the transition can be completed more quickly than in the case where other priorities are employed. That is, in the case of the composite system, the vertical synchronization signal is superimposed on the horizontal synchronization signal, and the vertical synchronization signal 102 has no signal. Therefore, when it is confirmed that a signal is present in the vertical synchronization signal 102, it is immediately understood that the signal is of the separate type.
Here, if the priority of the separate system is higher than that of the composite system, even if both the composite vertical synchronization signal and the separate vertical synchronization signal are detected, the state of “no synchronization signal input” 204 and the “separator” It is possible to immediately transit to the state of “synchronization signal selection” 201. On the other hand, when the priority of the composite system is set higher than that of the separate system, the state of “composite synchronization signal selection” 202 is first passed to the state of “separate synchronization signal selection” 201. The same applies to the relationship with SOG.

Some recent information processing devices output a plurality of types of synchronization signals. In such a type of information processing device, when entering the power saving mode, The output of some synchronization signals may be stopped. However, since the display control device of the first embodiment constantly monitors the synchronization signals of all the corresponding systems, even if the synchronization signal used so far is lost, the display control device quickly switches to another synchronization signal. By switching, a normal display can be maintained.

[Second Embodiment] As in the first embodiment, the liquid crystal display device of the second embodiment is characterized in that it can automatically identify the type of the synchronization signal input at that time and can respond to this. Things. However, the only types of synchronization signals that can be automatically identified are the separate system and the composite system.
It does not support the SOG method.

FIG. 3 shows the structure of the liquid crystal display device according to the second embodiment. The basic configuration is the same as in the first embodiment. However, due to the lack of support for the SOG method,
The part that handles the SOG synchronization signal is omitted. Specific differences are as follows.

The vertical synchronizing signal selector 113 selects one of the composite vertical synchronizing signal 104 and the vertical synchronizing signal 102.

In the composite system and the separate system, the input horizontal synchronizing signal 101 can be used as it is. Therefore, the horizontal synchronization signal selector 112 in the first embodiment is not provided, and the horizontal synchronization signal 101 is directly input to the liquid crystal module control signal generation circuit 114.

The sync separation circuit 110 also has only the function of separating and extracting the composite vertical sync signal 104 from the composite horizontal sync signal.

The determination and selection by the central processing circuit 111 are also
The third embodiment is the same as the first embodiment except that a part related to the SOG method is omitted. The priorities in the second embodiment are as follows.

FIG. 4 shows a state transition diagram of the central processing circuit 111. The difference from the first embodiment (FIG. 2) is that there is no “SOG synchronization signal selection” 203 state. Naturally, the "SOG
There is no transition route leading to the synchronization signal selection “203”.

Details of the state transition in the second embodiment will be described with reference to FIG.

While the power is on, the central processing circuit 111 always checks the presence or absence of the input of the vertical synchronizing signal of each system.

Initially, the central processing circuit 111 is in the state of “no synchronization signal input” 204.

When the presence of the separate vertical synchronizing signal 102 is detected in this state, the central processing circuit 111
It is determined that the method of the synchronization signal input at that time is the separate method. Therefore, the central processing circuit 111 shifts to the state of the separate synchronization signal selection 201 according to the determination result. Then, the selector 113 is caused to select the vertical synchronization signal 102.

In the state of “no sync signal input” 204, the presence of the composite vertical sync signal 104 is detected,
If the presence of the separate vertical synchronization signal 102 cannot be detected, the central processing circuit 111 determines that the system of the synchronization signal input at that time is the composite system. Therefore, according to the determination result, the central processing circuit 111
Moves to the state of “composite synchronization signal selection” 202. Then, the selector 113 selects the composite vertical synchronization signal 104.

When the presence of the separate vertical synchronization signal 102 is detected in the state of “composite synchronization signal selection” 202, the central processing circuit 111 moves to “separate synchronization signal selection” 201. When the presence of the composite vertical synchronization signal 104 cannot be detected, the state shifts to the state of “no synchronization signal input” 204.

When the presence of the separate vertical synchronization signal 102 is detected in the state of "separate synchronization signal selection" 201, the central processing circuit 111 keeps the state as it is. When the presence of the separate vertical synchronization signal 102 cannot be detected, the central processing circuit 111 moves to the state of “no synchronization signal input” 204.

As described above, according to the second embodiment,
The liquid crystal module can be controlled according to the input of the separate synchronization signal and the composite synchronization signal.

[Third Embodiment] The liquid crystal display device according to the third embodiment is characterized in that, as in the first embodiment, the type of the synchronization signal input at that time is automatically identified and can be handled. Things. However, only the separate system and the SOG system can be used for the automatically identifiable synchronization signal, and they do not support the composite system.

FIG. 5 shows the structure of the liquid crystal display device according to the third embodiment. The basic configuration is the same as in the first embodiment. However, a part for handling a composite synchronization signal is omitted because it does not support the composite method. Specific differences are as follows.

The vertical synchronization signal selector 113 selects one of the SOG vertical synchronization signal 106 and the vertical synchronization signal 102.

The horizontal synchronizing signal selector 112
One of the horizontal synchronization signal 105 and the horizontal synchronization signal 101 is selected.

The synchronization separation circuit 110 also has only a function of separating and extracting the SOG vertical synchronization signal 106 and the SOG horizontal synchronization signal 105 from the green signal 103.

The judgment and selection by the central processing circuit 111 are also
The third embodiment is the same as the first embodiment except that a part related to the composite method is omitted. The priorities in the third embodiment are as follows.

Separate method> SOG method FIG. 6 shows a state transition diagram of the central processing circuit 111. The difference from the first embodiment (FIG. 2) is that there is no “composite synchronization signal selection” 202 state. Naturally, there is no transition route leading to the “composite synchronization signal selection” 202.

When the power is turned on, the central processing circuit 111 always checks the presence or absence of the input of the vertical synchronizing signal of each system.

Initially, the central processing circuit 111 is in the state of “no synchronization signal input” 204.

When the presence of the separate vertical synchronizing signal 102 is detected in this state, the central processing circuit 111
It is determined that the method of the synchronization signal input at that time is the separate method. Therefore, the central processing circuit 111 shifts to the state of the separate synchronization signal selection 201 according to the determination result. Then, the selectors 112 and 113 are caused to select the synchronization signals 101 and 102.

In the state of "no synchronization signal input" 204, if the presence of the SOG vertical synchronization signal 106 is detected and the presence of the separate vertical synchronization signal 102 cannot be detected, the central processing circuit 111 receives the input at that time. It is determined that the method of the synchronization signal is the SOG method. Therefore,
The central processing circuit 111 selects “SOG synchronization signal selection” 203
Move to the state. Then, the selectors 112 and 113 are caused to select the synchronization signals 105 and 106.

When the presence of the separate vertical synchronization signal 102 is detected in the state of “SOG synchronization signal selection” 203, the central processing circuit 111 moves to the state of “separation synchronization signal selection” 201. SOG vertical synchronization signal 106
When it is no longer possible to detect the presence of a "Synchronization signal input", the state shifts to the state of "No synchronization signal input" 204.

When the presence of the separate vertical synchronization signal 102 is detected in the state of "separate synchronization signal selection" 201, the central processing circuit 111 keeps the state as it is. When the presence of the separate vertical synchronization signal 102 cannot be detected, the central processing circuit 111 moves to the state of “no synchronization signal input” 204.

As described above, according to the third embodiment,
The liquid crystal module can be controlled according to the input of the separate synchronization signal and the SOG synchronization signal.

[Fourth Embodiment] The liquid crystal display device of the fourth embodiment is characterized in that, as in the first embodiment, the type of the synchronization signal input at that time is automatically identified and can be handled. Things. However, only the composite system and the SOG system are available for the automatically identifiable synchronization signal, and do not support the separate system.

FIG. 7 shows the structure of the liquid crystal display device according to the fourth embodiment. The basic configuration is the same as in the first embodiment. However, a part for handling the vertical synchronization signal 102 is omitted because it does not support the separate system. Specific differences are as follows.

The vertical synchronization signal selector 113 selects one of the SOG vertical synchronization signal 106 and the composite vertical synchronization signal 104.

The horizontal synchronizing signal selector 112
One of the horizontal synchronization signal 105 and the horizontal synchronization signal 101 is selected.

The judgment and selection by the central processing circuit 111 are also
The third embodiment is the same as the first embodiment except that a part related to the separate system is omitted. The priorities in the fourth embodiment are as follows.

Composite System> SOG System FIG. 8 is a state transition diagram of the central processing circuit 111. The difference from the first embodiment (FIG. 2) is that there is no “separate synchronization signal selection” 201 state. Naturally, there is no transition route leading to the “separate synchronization signal selection” 201.

When the power is turned on, the central processing circuit 111 always checks the presence or absence of the input of the vertical synchronizing signal of each system.

Initially, the central processing circuit 111 is in the state of “no synchronization signal input” 204.

When the presence of the composite vertical synchronizing signal 104 is detected in the state of "no synchronizing signal input" 204, the central processing circuit 111 determines that the type of the synchronizing signal inputted at that time is the composite type. I do. Therefore, according to the determination result, the central processing circuit 111
Moves to the state of “composite synchronization signal selection” 202. Then, the selectors 112 and 113 are caused to select the synchronization signals 101 and 104.

In the state of "no synchronization signal input" 204, if the presence of the SOG vertical synchronization signal 106 is detected and the presence of the composite vertical synchronization signal 104 cannot be detected, the central processing circuit 111 receives the input at that time. It is determined that the method of the synchronization signal is the SOG method. Accordingly, the central processing circuit 111 performs “SOG synchronization signal selection” 2
Move to the state of 03. Then, the selectors 112 and 11
3 causes the synchronization signals 105 and 106 to be selected.

When the presence of the composite vertical synchronization signal 104 is detected in the state of “SOG synchronization signal selection” 203, the central processing circuit 111 moves to the state of “composite synchronization signal selection” 202. SOG vertical synchronization signal 1
If it is not possible to detect the presence of the “06”, the state shifts to the state of “no synchronization signal input” 204.

When the presence of the composite vertical synchronization signal 104 is detected in the state of "composite synchronization signal selection" 202, the state is maintained. If the presence of the composite vertical synchronization signal 104 cannot be detected,
The state moves to the state of “no synchronization signal input” 204.

As described above, according to the fourth embodiment,
The liquid crystal module can be controlled according to the input of the composite synchronization signal and the SOG synchronization signal.

Embodiments 1 to 4 described above
In the above, the method of the synchronization signal input at that time was determined by determining whether or not each vertical synchronization signal substantially exists (that is, “presence or absence of a wave”). However, the method of determining the method of the synchronization signal is not limited to this. For example, the determination can be made by counting the pulses included in each synchronization signal. Such an example is described in the fifth embodiment.
It will be described as.

[Fifth Embodiment] The fifth embodiment is a judgment circuit for judging the scheme of a synchronization signal. This determination circuit is used in place of the central processing unit 111 in the first embodiment.

The determination circuit comprises a counting circuit 401, a count value 402, a comparing circuit 404, and a selection signal generating circuit 405, as shown in FIG.

The counting circuit 401 has the vertical synchronizing signal 102
And the composite vertical synchronizing signal 104 and the SOG vertical synchronizing signal 106 are input. The counting circuit 401 counts pulses of the separate vertical synchronization signal 102, the composite vertical synchronization signal 104, and the SOG vertical synchronization signal 106, respectively. Then, the coefficient value 402 is output to the comparison circuit 404. The comparison circuit 404 compares the count value 402 with a predetermined value 403. As a result, if each count value 402 is equal to or more than the value 403, it is determined that the synchronization signal exists. The selection signal generation circuit 405 generates an exclusive selection signal 107 according to the determination result.

The present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the scope of the invention. For example, Embodiment 5
Can be used in place of the central processing circuit in the second, third, and fourth embodiments.

In the above description, the central processing circuit 111,
The determination circuit has been described as determining the type of the synchronization signal input at that time. However, strictly speaking, the object of the present invention can be achieved even if the "method" of the synchronization signal cannot be determined. It is only necessary to know where the synchronization signal exists (in the above-described embodiment, which of the signal lines 102, 104, and 106 has the synchronization signal). Strictly speaking, the priority may not be assigned to the "method" of the synchronization signal but may be assigned to the signal line. Therefore, according to the signal line having the highest priority among the signal lines where the signal was present,
It is only necessary to control the states of the selectors 112 and 113.
Of course, if the central processing circuit 111 is provided with information in which the signal lines 102, 104, and 106 are associated with the method of the synchronization signal, the "method" of the synchronization signal can be determined. Then, the selectors 112 and 113 may be controlled based on the determination result (that is, the “method” of the synchronization signal). In this case, the selectors 112 and 113
Also, the selected state is associated with the "method" of the synchronization signal. The content of the selection signal 107 indicates the "method" of the synchronization signal. Claims 7 to 11 (the second aspect of the present invention in the section of the means for solving the problem) are from such a viewpoint.

[0115]

As described above, according to the present invention, it is possible to automatically identify the type of the synchronization signal and automatically respond to the synchronization signal input at that time. Therefore, there is no need to worry about the type of the synchronization signal. In addition, it can correspond to all kinds of personal computers and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a state transition diagram for determining a synchronization signal system of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a block diagram illustrating a schematic configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a state transition diagram of a liquid crystal display device according to a second embodiment of the present invention for determining a synchronization signal system.

FIG. 5 is a block diagram illustrating a schematic configuration of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 6 is a state transition diagram of a liquid crystal display device according to a third embodiment of the present invention for determining a synchronization signal system.

FIG. 7 is a block diagram illustrating a schematic configuration of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 8 is a state transition diagram of a liquid crystal display device according to a fourth embodiment of the present invention for determining a synchronization signal system.

FIG. 9 is a block diagram illustrating a schematic configuration of a determination circuit according to another embodiment of the present invention.

FIG. 10 is a block diagram showing a schematic configuration of a conventional liquid crystal display circuit.

[Explanation of symbols]

101: horizontal synchronization signal, 102: vertical synchronization signal, 103
... green signal, 104 ... composite vertical sync signal, 10
5: SOG horizontal synchronization signal, 106: SOG vertical synchronization signal, 107: selection signal, 108: selected horizontal synchronization signal,
109: vertical sync signal after selection, 110: sync separation circuit,
111: central processing circuit; 112: horizontal synchronization signal selector; 113: vertical synchronization signal selector; 114: control signal generation circuit for liquid crystal module; 115: control signal for liquid crystal module; 116: liquid crystal module.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Takeshi Maeda Takeshi Maeda 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi Image Information System Co., Ltd. (72) Hiroshi Kurihara 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Devices Division (72) Inventor Shigehiko Kasai 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi, Ltd.System Development Laboratory (72) Inventor Nobutaka Kato 810 Shimoimaizumi, Ebina-shi, Kanagawa Hitachi Office, Ltd. System Division

Claims (12)

[Claims] 1. A display control device for generating a control signal for controlling a display device based on a signal including a synchronization signal input from the outside, comprising: a plurality of input signals to which the signal including the synchronization signal is input; A line, determining means for determining whether the type of the synchronization signal input at that time is one of predetermined methods, and determining whether the input signal line to which the synchronization signal is input at that time is A selector that selects based on the determination result of the determination unit and outputs a synchronization signal transmitted through the input signal line; and a control signal generation circuit that generates a control signal based on the synchronization signal output from the selector. A display control device comprising: 2. A horizontal synchronizing signal and / or a vertical synchronizing signal are extracted from an original signal on which a vertical synchronizing signal and / or a horizontal synchronizing signal are superimposed. The display control device according to claim 1, further comprising a separating unit that outputs the signal to the input signal line that is predetermined according to a type of the original signal. 3. A method according to claim 1, wherein the predetermined method is a separate method in which the horizontal synchronization signal and the vertical synchronization signal are carried as independent signals, and a method in which the horizontal synchronization signal and the vertical synchronization signal are superimposed and carried as one signal. And at least two of a composite method and a SOG method in which a horizontal synchronizing signal and a vertical synchronizing signal are superimposed on a green signal of a video signal and conveyed as one signal. 3. The liquid crystal display device according to 2. 4. The display control apparatus according to claim 1, wherein said determination means makes said determination based on the presence or absence of a vertical synchronization signal for each of said predetermined schemes. 5. A method according to claim 1, wherein said plurality of synchronization signals have predetermined priorities, and as a result of the determination by said determination means, when a plurality of types of synchronization signals are detected, said signals are detected in accordance with said priorities. 2. A method according to claim 1, further comprising selecting means for selecting one of the selected methods, wherein the selector selects and outputs a synchronization signal of the method selected by the selecting means. Display control device. 6. A separate system for carrying the horizontal synchronization signal and the vertical synchronization signal as independent signals, and a system for superimposing the horizontal synchronization signal and the vertical synchronization signal as one signal. And a SOG system in which a horizontal synchronizing signal and a vertical synchronizing signal are superimposed on a green signal of a video signal and conveyed as one signal. The display control device according to claim 5, wherein the order is:> composite method> SOG method. 7. A display control device for generating a control signal for controlling a display device based on an externally input signal, comprising: a plurality of input signal lines to which a signal including a synchronization signal is input; Determining means for determining whether or not a synchronization signal is actually input at that time for a predetermined one of the lines; and determining by the determination means whether or not the synchronization signal is input at that time among the input signal lines A selector that selects based on the result and outputs a synchronization signal sent through the input signal line; and a control signal generation circuit that generates a control signal based on the synchronization signal output from the selector. Display control device. 8. The determination means determines whether or not a vertical synchronization signal is actually input to the input signal line among the input signal lines to which a vertical synchronization signal is input at that time. The display control device according to claim 7, wherein: 9. The counting means for counting the number of pulses input to the predetermined input signal line at the time, a predetermined value, and a counting result of the counting circuit and the predetermined value. A comparison circuit that compares the value with the selected value, and a selection signal generation circuit that generates a selection signal that controls the selector based on a comparison result of the comparison circuit. The display control device according to the above. 10. An original signal in which at least two of a horizontal synchronizing signal, a vertical synchronizing signal, and a video signal are superimposed, and a horizontal synchronizing signal and / or a vertical synchronizing signal are separated from the original signal. And the separated horizontal synchronization signal and / or
8. The display control according to claim 7, further comprising separating means for outputting the vertical synchronizing signal to a predetermined input signal line according to the original signal of the horizontal synchronizing signal and / or the vertical synchronizing signal. apparatus. 11. A method according to claim 8, wherein said input signal lines have a priority set between input signal lines to which a vertical synchronizing signal is input, and wherein said judging means detects a synchronizing signal on a plurality of input signal lines. Selecting means for selecting any one of the input signal lines based on the priority order, wherein the selector causes the selecting means to output a synchronization signal transmitted through the selected input signal line; 11. The display control device according to claim 7, 8, 9, or 10. 12. The method of claim 1, 2, 3, 4, 5, 6, 7,
A display device, comprising: the display control device according to 8, 9, 10, or 11, and a liquid crystal module that displays an image based on the control signal and image data that is separately input.