JP2897810B2 - Input video signal system identification / switching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-scan type image display device (CRT (Cathode Ray Tu)).
be), the type of the system of the input video signal (video signal input to the image display device) by the automatic frequency tracking function in the liquid crystal display, the plasma display, and the like, that is, the determination of the model of the computer that outputs the video signal and the determination. The present invention relates to an input video signal system discrimination / switching method for performing switching of image data based on an image signal.

[0002]

2. Description of the Related Art In general, for example, systems of video signals output from various computers of different manufacturers are not unified, and video signals of different systems (for example, video signals having different resolutions) are used. . In a multi-scan monitor (multi-scan type image display device) capable of displaying video signals output from such various computers, image size correction, screen position correction, and the like according to the system of input video signals are performed. Image distortion correction, and it is necessary to switch image data in accordance with the input video system.

That is, in a multi-scan type image display device, a system of an input video signal is determined, and image data is switched based on the determination. Method is required.

Conventionally, in this type of input video signal system discrimination / switching method, the horizontal frequency and vertical frequency of an input video signal of an image display device and the polarity of a sync signal (hereinafter referred to as sync polarity) are determined by an automatic frequency tracking function. The following features are provided on the premise that tracking and system determination and switching of an input video signal are performed based on the tracking.

[0005] The concept of an area for system determination (determination area) is provided for the horizontal frequency and the vertical frequency. This area is continuous, the area of the area is relatively wide, and any video signal within the area is determined to be the same video signal.

There is a changeover switch called a mode switch or a memory switch, and multiplexing of the area mentioned by turning on / off of the mode switch or the like becomes possible (for example, registration of fixed standard image data and registration by a user is performed). It is possible to make the mode different depending on the registered image data that can be used).

[0007] Switching of the input video signal has been recognized by a single decision. That is, when the input video output changes for some reason, it is recognized that the system of the input video signal is immediately switched.

[0008]

The above-described conventional input video signal system discriminating / switching method has the following problems due to the above-mentioned features.

[0009] Since the range of the area for system determination is wide, and no matter what video signal comes within the area, it is recognized as the same, and there is a possibility that the certainty of the determination may be lacking. Is difficult to determine.

[0010] Since the user needs to operate a changeover switch (such as a mode switch) at the time of mode switching, the operation of determining the system of the input video signal becomes complicated.

Since the switching of the system of the input video signal is recognized by a single determination, there is a high possibility that an erroneous determination is made based on noise or signal instability.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to improve the reliability of system determination of an input video signal, to be able to determine more systems, to eliminate the need to operate a changeover switch, to reduce noise and the like. An object of the present invention is to provide an input video signal system discrimination / switching method that can reduce erroneous judgments or the like caused by the above.

As a prior art relating to automation of discrimination of a system of an input video signal, Japanese Patent Laid-Open No. 4-271 is disclosed.
No. 395 (Multi-scan monitor system determination method of input video signal and multi-scan monitor). However, this technology is capable of setting up as many user systems as necessary (corresponding to the video signal system according to the registered image data of the present invention) and automatically and automatically setting the optimal system for the input video signal. The discriminable profit (refer to page 786, right column, lines 24 to 27 in the gazette) ",
Further, in the point that the concept of the area is still used in the determination of the system, the present invention differs from the present invention in the purpose and configuration.

[0014]

According to the present invention, there is provided an input video signal system discriminating / switching method, comprising: a standard image data storage section for storing standard image data which is fixed image data; A registered image data storage unit for storing the horizontal frequency, the vertical frequency and the synchronization polarity together with a corresponding horizontal frequency, a vertical frequency and a synchronization polarity; An RGB synchronization determining unit that determines the identity between the current input video signal and the reference video signal based on the input signal data detected by the input signal data detecting unit; If it is determined that the search is performed, the registered image data storage unit is searched first, and then the previous Performs a search of the standard image data storage unit, performs system determination of the input video signal based on these search organic and auto scan setting unit for setting the image data corresponding to the determined system the image data adjustment unit And the signal inference algorithm uses the standard image
The standard image data stored in the image data storage
Grouped by frequency and vertical frequency,
When searching the standard image data storage, first input signal data
Is the predetermined horizontal frequency for each group
Based on the value of
Grouping process and grouping by horizontal frequency
If the vertical frequency in the input signal data is
To the predetermined vertical frequency value and the allowable range
Grouping based on inclusion and vertical
In the input signal data if grouping by frequency is possible
The determination of the synchronization polarity is performed .

[0015]

According to the input video signal system discrimination / switching method of the present invention, the standard image data storage section stores standard image data which is fixed image data, and the registered image data storage section stores the registered image data registered by the user. With the corresponding horizontal frequency, vertical frequency and sync polarity,
The input signal data detection unit detects the horizontal frequency, the vertical frequency, and the synchronization polarity of the input video signal at regular intervals as input signal data, and the RGB synchronization determination unit detects the input signal data based on the input signal data detected by the input signal data detection unit. The identity of the current input video signal and the reference video signal is determined, and when the auto scan set unit determines that both signals are different signals by the RGB synchronization determination unit, first, the auto scan set unit stores the registered image data in the registered image data storage unit. A search is performed, and then the standard image data storage unit is searched by a signal inference algorithm, a system of the input video signal is determined based on the search, and image data corresponding to the determined system is converted to an image data adjustment unit. Set to. The signal inference algorithm
The standard image data stored in the quasi-image data storage
Grouped by horizontal frequency and vertical frequency,
When searching the standard image data storage, first input signal data
Is the predetermined horizontal frequency for each group
Based on the value of
Grouping process and grouping by horizontal frequency
If the vertical frequency in the input signal data is
To the predetermined vertical frequency value and the allowable range
Grouping based on inclusion and vertical
In the input signal data if grouping by frequency is possible
Is determined.

[0016]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an input video signal system discriminating / switching system according to one embodiment of the present invention.

The input video signal system discriminating / switching method of this embodiment is based on a ROM (Read Only Memory).
y) a standard image data storage unit 1 realized by
EPROM (Electrically Erasab)
le programmable ROM), a registered image data storage unit 2 and a control unit 3
(An input device for performing adjustment and operation control; not described in the following description); an input signal data detection unit 7 including a horizontal frequency detection unit 4, a vertical frequency detection unit 5, and a synchronization polarity detection unit 6; CPU (Central) including a unit 8 and an auto scan set unit 9
(Processing Unit) 10, an image data adjustment unit 11, and an image display unit 12.

FIG. 2 is a flowchart showing the overall processing flow of the input video signal system discrimination / switching system of this embodiment. This processing is performed by the input signal data detection unit processing step 2
01, an RGB synchronization determination section processing step 202, an identical signal / different signal determination step 203, and an auto scan set section processing step 204.

FIG. 3 is a flowchart showing the processing of the RGB synchronization discriminating section 8. This processing is performed in synchronization flag determination step 3
01, an input signal data acquisition step 302, an acquired data error check step 303, an input video signal presence / absence check step 304, a blue back determination step 305, a continuous reception determination step 306, a synchronization flag 1 setting step 307, An interlace discrimination check step 308, a vertical frequency correction step 309,
Blue-back determination step 310, continuous reception determination step 311, synchronization flag 1 setting step 312, horizontal frequency check step 313, vertical frequency check step 314, and synchronization polarity check step 315.
, A continuous reception determination step 316, and a synchronization flag 1 setting step 317.

FIG. 4 is a flow chart showing the processing of the automatic scan setting section 9. This processing includes a synchronization flag determination step 401, a registered image data storage unit check step 402, a registered image data calling step 403, a signal inference algorithm processing step 404, a standard image data calling step 405, and an image data setting step 406. And a synchronization flag 0 setting step 407.

FIG. 5 is a flowchart showing the processing of the signal estimation algorithm. This processing includes an Hf grouping processing step 501 and an input video signal unknown determination step 502.
Vf grouping processing step 503, input video signal unknown determination step 504, horizontal frequency determination steps 505-1 to 505-n, vertical frequency determination steps 506-1 to 506-m, and synchronization polarity determination step 50
7-1 to 507-m and an input video signal system determination step 508.

FIGS. 6 and 7 are diagrams for explaining the signal estimation algorithm.

FIG. 8 is a diagram showing an example of the contents of the standard image data storage unit 1. In the standard image data storage unit 1, image data (here, information indicating image distortion correction data and the like) corresponding to a plurality of types of known video signal systems is stored as fixed data in advance. The data in the standard image data storage unit 1 does not need the horizontal frequency, the vertical frequency, and the synchronization polarity, and storage variables are stored as information for identifying each image data.

FIG. 9 is a diagram showing the configuration of the registered image data storage unit 2. The registered image data storage unit 2 includes a plurality of areas identified by registered variables.

The difference between the standard image data storage unit 1 and the registered image data storage unit 2 is that in the standard image data storage unit 1, the image data is called after the system (the system of the input video signal) is determined by the signal inference algorithm. Therefore, the horizontal frequency, the vertical frequency, and the synchronization polarity corresponding to each system are not required, whereas the registered image data storage unit 2 stores the system corresponding to the registered image data and the system of the current input video signal. The horizontal frequency, the vertical frequency, and the synchronization polarity are stored together with the image data in each area for comparison and determination.

Next, the operation of the input video signal system discriminating / switching system configured as described above will be described.

The input signal data detecting section 7 receives the input signal data (horizontal frequency Hf, vertical frequency Vf and synchronization polarity Syn of the input video signal) at regular intervals (for example, several milliseconds).
c) is detected (step 201).

The RGB synchronization determining section 8 in the CPU 10 determines a video signal (hereinafter, referred to as a reference video signal) relating to an image currently displayed on the basis of the detection result (input signal data) of the input signal data detecting section 7. Horizontal frequency, vertical frequency and sync polarity of the current input video signal
Determination of the identity between the vertical frequency and the synchronization polarity is performed (step 202).

Further, based on the value of the synchronization flag and the like set by the processing of the RGB synchronization discriminating section 8 in step 202, the CPU 10 determines whether or not the current input video signal and the reference video signal are the same system ( It is determined whether the signals are the same signal or different signals (step 203).

When it is determined in step 203 that the signal is the same (when the synchronization flag is 0 or when the synchronization flag is already 1 at the start of the process in step 202 immediately before), the current state is maintained and the constant state is maintained. After a lapse of time, the process of step 201 is repeated.

If it is determined in step 203 that the signal is a different signal (the synchronization flag is changed from 0 to 1
Is changed to), the control is transferred to the processing of the auto scan set unit 11 in order to match the current input video signal system.

The auto scan set unit 9 searches the system of the current input video signal in the order of the registered image data storage unit 2 and the standard image data storage unit 1, and adjusts the image data corresponding to the searched system to image data. Part 1
It is set to 1 (step 204).

The image data adjustment section 11 performs conversion of a digital signal into an analog signal based on the image data, and controls the display of an image on the image display section 12.

Next, the processing of the RGB synchronization determination section 8 will be described in detail (see FIG. 3).

The RGB synchronization discriminating section 8 compares the horizontal frequency, vertical frequency and synchronization polarity of the current input video signal with the horizontal frequency, vertical frequency and synchronization polarity of the reference video signal to thereby determine the current input video signal. The identity between the system and the system of the reference video signal is determined.

The horizontal frequency of the current input video signal,
By comparing the vertical frequency and synchronization polarity with the horizontal frequency, vertical frequency and synchronization polarity of the previous input video signal, it is possible to prevent erroneous determination (this corresponds to the invention according to claim 2). . In this case,
The RGB synchronization determination unit 8 holds input signal data relating to a previous input video signal.

First, it is determined whether or not the synchronization flag is 0 with reference to a synchronization flag for controlling whether or not the RGB synchronization determination section 8 and the auto scan set section 9 can be executed (step 301).

If it is determined in step 301 that the synchronization flag is not 0 (it is 1), it is recognized that the auto scan set section 9 is being executed, and the process is terminated (the entire process shown in FIG. 2). The control is returned to the processing of step 20.
Control is transferred to the determination of 3).

If it is determined in step 301 that the "synchronization flag is 0", the following determination is made and input signal data is obtained (step 302).

Next, after performing an acquired data error check (check for an error in the input signal data acquired in step 302) (step 303), the presence or absence of an input video signal is checked (step 304).

"No input video signal" in step 304
Is determined, it is determined whether or not the current display state is the background color when there is no signal (generally, the background color is blue-back, henceforth simply referred to as "blue-back") (step 305). .

If it is determined in step 305 that "the current display state is blue back", the processing is terminated. If it is determined in step 305 that “the current display state is not the blue screen”, it is determined whether the same input signal data as the previously obtained input signal data is also obtained this time (the previous input video signal Whether the horizontal frequency, vertical frequency and sync polarity of the current input video signal are the same as the horizontal frequency, vertical frequency and sync polarity of the current input video signal;
That is, it is determined whether or not “continuous reception” (step 306).

If it is determined in step 306 that "continuous reception" is set, the synchronization flag is set to 1 (step 3).
07) Then, the process ends. Step 30
If it is determined in step 6 that the reception is not continuous, the process is terminated.

In step 304, "there is an input video signal"
If it is determined that the scanning method is interlaced (step 308) and the vertical frequency is corrected by the horizontal frequency when the scanning method is interlaced (step 309), the current display state is determined. Is a blue back (step 310).

If it is determined in step 310 that "the current display state is blue back", it is determined whether or not continuous reception is performed (step 311).

If it is determined in step 311 that the reception is "continuous reception", the synchronization flag is set to 1 (step 311).
12) Then, the process ends. Step 31
If it is determined in step 1 that the reception is not continuous, the process is terminated.

If it is determined in step 310 that the current display state is not blue-back, a horizontal frequency check (step 313), a vertical frequency check (step 314) and a synchronization polarity check (step 315)
To determine the identity of the system of the reference video signal with the system of the current input video signal.

That is, if all of the horizontal frequency, vertical frequency and synchronization polarity of the current input video signal are within the allowable range of the horizontal frequency, vertical frequency and synchronization polarity of the reference video signal, they are identical. Then, the process is terminated. The “permissible range” is set in advance based on an empirical standard or the like.

On the other hand, the horizontal frequency of the current input video signal,
If any of the vertical frequency and the synchronization polarity is out of the allowable range of the horizontal frequency, the vertical frequency and the synchronization polarity of the reference video signal, it is determined whether or not the reception is continuous (step 316).

If it is determined in step 316 that "continuous reception" is set, the synchronization flag is set to 1 (step 3).
17) Then, the process ends. Step 31
If it is determined in step 6 that the reception is not continuous, the process is terminated.

As described above, in this embodiment, when the input video signal and the reference video signal are the same signal, the current state is maintained, and when the input video signal and the reference video signal are different signals, the different signals are continuously received. As long as the synchronization flag is set to 1, a system search is performed by the auto scan setting unit 9 described later. Therefore, the system search is not performed unless continuous reception is performed, so that malfunction at the time of trouble due to noise and at the time of signal instability is avoided.

Next, the processing of the automatic scan setting section 9 will be described in detail (see FIG. 4).

First, it is confirmed that the synchronization flag is 1, and it is determined that a system search for the current input video signal should be performed (step 401).

In this system search, the registered image data storage unit 2 is first checked to determine whether there is any image data corresponding to the registered image data storage unit 2 (the horizontal frequency, the vertical frequency and the It is determined whether or not an area having image data corresponding to the same horizontal and vertical frequencies and synchronization polarity as the synchronization polarity exists in the registered image data storage unit 2 (step 402).

If it is determined in step 402 that "there is image data corresponding to the registered image data storage unit 2",
The image data (registered image data) is called from the registered image data storage unit 2 (step 403).

If it is determined in step 402 that "there is no corresponding image data in the registered image data storage unit 2" (if there is no image data in any area in the registered image data storage unit 2), a signal The image data in the standard image data storage unit 1 is searched by the inference algorithm (step 404), and the desired image data (standard image data) in the standard image data storage unit 1 is called (step 405).

Here, in the signal estimation algorithm, determination using the concept of area as in the prior art is not performed, but determination is performed using the concept of points for the horizontal frequency and the vertical frequency.

If the system of the current input video signal is still unknown by this signal estimation algorithm, finally, the system of the current input video signal and the system of the current input video signal are referred to by a conventional algorithm (referred to as an approximate signal algorithm in the present invention). It is also possible to search for image data corresponding to the system, and call that image data (here, referred to as approximate image data) as new image data (see the invention according to claim 3).

As described above, the system search is performed in the order of the registered image data and the standard image data (and, in some cases, more approximate image data) (an order that allows easy user adjustment as much as possible).

Finally, the image data corresponding to the system of the current input video signal finally recognized by the above system search is set in the image data adjusting unit 11 (step 406), and the synchronization flag is cleared (synchronization). The flag is set to 0) (step 407). When the synchronization flag is cleared in this way, the monitoring processing of the input video signal by the RGB synchronization determination unit 8 becomes operable (see step 301 in FIG. 3).

Here, the signal estimation algorithm shown in step 404 in FIG. 4 will be described in detail with reference to FIGS.

In the signal inference algorithm, first, it is determined which group the horizontal frequency in the input signal data belongs to (Hf grouping process) (step 5).
01). Here, it is assumed that the data is classified into n groups H1 to Hn (see FIG. 7). The determination as to whether or not the input signal data belongs to each group is made by determining whether or not the horizontal frequency in the input signal data is included in a predetermined horizontal frequency value (a value captured by the concept of a point) relating to each group and an allowable range in the vicinity thereof. It is done by or. That is, grouping is performed based on the concept of points, not the concept of areas.

After the processing of step 501, step 50
If it is determined in the grouping process 1 that the horizontal frequency of the input video signal does not belong to any group (when the input video signal is unknown) (step 502), the process ends immediately at that time. (The useless determination is avoided as much as possible).

If it is determined in step 502 that "the horizontal frequency in the input signal data belongs to any group", it is determined which group the vertical frequency in the input signal data belongs to (Vf grouping). Process) is performed (step 503). Here, it is assumed that the data is classified into m groups V1 to Vm (see FIG. 7). The determination as to whether or not each group belongs is performed based on the concept of a point, as in the grouping process in step 501.

After the processing of step 503, step 50
If it is determined in the grouping process 3 that the vertical frequency of the input video signal does not belong to any group (if the input video signal is unknown) (step 504), the process ends immediately at that time. .

If it is determined in step 504 that "the vertical frequency in the input signal data belongs to any group", the synchronization polarity in the input signal data is determined based on the grouping process in steps 501 and 503. A determination is made.

That is, steps 505-1 to 505-
In the determination of n, the horizontal frequency is identified, and in step 506-1
506-m, the vertical frequency is identified, and in the determinations in steps 507-1 to 507-m, the determination of the system of the current input video signal is performed (final), taking into account the determination of the synchronization type. (Step 508). As a result, a storage variable (see FIG. 8) indicating the number of the data area (area in the standard image data storage unit 1) of the image data (standard image data) corresponding to the system of the current input video signal is designated. Image data corresponding to the storage variable is set in the image data adjustment unit 11.

Note that the synchronization polarity is set to separate HV-,
They are grouped into separate H + V-, separate HV +, separate H + V +, composite sync and G sync (see FIG. 7).

As described above, in the signal estimation algorithm,
Grouping and discrimination are performed based on the three elements of the horizontal frequency, the vertical frequency, and the synchronization polarity (see FIGS. 6 and 7).

[0071]

As described above, according to the present invention, the system of the present input video signal is discriminated by the concept of a point based on the horizontal frequency, the vertical frequency, and the synchronization polarity, so that the system of the input video signal can be reliably determined. Has an effect that it is possible to store image data corresponding to many systems in the standard image data storage unit.
There is an effect that a troublesome operation by the user for switching the changeover switch is not required).

Further, in the determination of the system of the current input video signal, it is not determined that the system is switched unless the input video signal different from the reference video signal is continuously received. There is an effect that it can be avoided.

Further, by searching in the order of registered image data and standard image data (and, in some cases, approximate image data), the system of most video signals is determined, and useless determination is avoided as much as possible by the signal estimation algorithm. Since such control is performed, there is an effect that appropriate system determination can be automatically performed faster.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment according to an input video signal system determination / switching method of the present invention.

FIG. 2 is a flowchart showing the overall processing flow of the input video signal system determination / switching method shown in FIG.

FIG. 3 is a flowchart showing a detailed process of an RGB synchronization determination unit in FIG. 1;

FIG. 4 is a flowchart showing a detailed process of an auto scan set unit in FIG. 1;

FIG. 5 is a flowchart showing a detailed process of a signal inference algorithm in FIG. 4;

FIG. 6 is a diagram showing a hierarchy of the signal inference algorithm shown in FIG. 5;

FIG. 7 is a diagram showing an outline of a signal estimation algorithm shown in FIG. 5;

FIG. 8 is a diagram showing an example of the contents of a standard image data storage unit in FIG. 1;

FIG. 9 is a diagram illustrating a configuration of a registered image data storage unit in FIG. 1;

[Description of Signs] 1 Standard image data storage unit 2 Registered image data storage unit 3 Control unit 4 Horizontal frequency detection unit 5 Vertical frequency detection unit 6 Sync polarity detection unit 7 Input signal data detection unit 8 RGB synchronization determination unit 9 Auto scan set Unit 10 CPU 11 Image data adjustment unit 12 Image display unit

Claims (4)

(57) [Claims] 1. A standard image data storage unit for storing standard image data as fixed image data, and registered image data for storing registered image data registered by a user together with corresponding horizontal frequency, vertical frequency and synchronization polarity. A storage unit; an input signal data detection unit that detects a horizontal frequency, a vertical frequency, and a synchronization polarity of the input video signal at regular intervals as input signal data; and a storage unit that detects the input signal data based on the input signal data detected by the input signal data detection unit. An RGB synchronization determining unit for determining the identity between the current input video signal and the reference video signal; and when the RGB synchronization determining unit determines that both signals are different signals, first, the registered image data storage unit A search is performed, and then the standard image data storage unit is searched by a signal inference algorithm. Performs system determination of the input video signal, the image data corresponding to the determined system and a auto scan setting unit for setting the image data adjustment unit, the signal inferred algorithm, the standard image data storage
The standard image data stored in the
Grouped by vertical frequency, the standard image data
When searching the data storage section, first,
The wave number is the value of the predetermined horizontal frequency for each group and its vicinity.
Group based on whether or not included
Input if it can be grouped by horizontal frequency.
The vertical frequency in the force signal data is
Vertical frequency value and whether it falls within the permissible range
Grouping based on the
If grouping is possible, the synchronization polarity in the input signal data
An input video signal system discrimination / switching method characterized by performing discrimination . 2. The input video signal system discrimination / switching method according to claim 1, further comprising an RGB synchronization discrimination unit for checking continuous reception. 3. The apparatus according to claim 1, further comprising an auto scan set section for performing a search for approximate image data when the system of the current input video signal is unknown even by searching the standard image data storage section. 2. The input video signal system discrimination / switching method described in 2. 4. A system according to claim 1, wherein the standard image data storage section is realized by a ROM, and the registered image data storage section is realized by an EEPROM. -Switching method.