JPH08172587A - On-screen display device - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if the scan speed of the signal source input to the multi-scan display device changes, the number of parts may increase due to the addition of the OSD-IC and its peripheral circuits, and the cost associated therewith (EN) Provided is an on-screen display device capable of displaying on-screen display characters having a constant aspect ratio on a display without causing an increase. [Configuration] Video Deck 1 that outputs Normal Scan signal, EDTV Decoder 2 that outputs Double Scan signal, Input Selector Switch 4, OSD-IC 7, which has character pattern font data for Normal Scan and Double Scan, input A control circuit 14 that outputs a font data selection command to the OSD-IC 7 based on the scan speed information sent from the changeover switch 4, and a video processing circuit that synthesizes the signals sent from the input changeover switch 4 and the OSD-IC 7 5 and video processing circuit 5
It is composed of CRT6 that displays the signal from the display.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-screen circuit for on-screen display on a CRT screen or a liquid crystal screen (hereinafter referred to as CRT screen, etc.), a control circuit for controlling the circuit, and an on-screen display. The present invention relates to a device having a video circuit for performing the above, and more particularly to an on-screen display technique in a device capable of multi-scan scanning, which can change the scan speed according to a signal source input to the device.

[0002]

2. Description of the Related Art Recently, with the advancement and diversification of video sources, demands for high-performance monitors and multi-function monitors for more faithfully reproducing the original image information of the sources are increasing.

For example, in fields such as broadcasting stations and high-grade commercial use, high-definition CRT-based high-definition monitors are in progress, with video production aimed at and ahead of the next-generation high-definition television era. Are being demanded. In addition, IDTV (improved definition T
For the development of V) and EDTV (high definition TV), a so-called high-scan (double-density) monitor of wide band and double speed scanning is required.

On the other hand, VTRs for both business and personal use
Various sources such as video discs, other communication networks, and personal computers have become widespread at the same time, and the demand for multipurpose monitors capable of monitoring these in optimal conditions is also increasing.

FIG. 6 is a diagram showing a multi-scan display device and various video sources.

In the normal broadcasting system, the horizontal scanning frequency (f
h) is 15.75kHz and vertical scanning frequency (fv) is 60Hz, but in order to improve the vertical density, fh is
It is considered to raise it to 64kHz or 100kHz or more, and a wide range of frequencies of 40Hz to 120Hz is also considered for fv. However, in order to cover such a wide range of scanning frequencies with a single monitor, a circuit system is required. It will be very complicated and will cause a significant cost increase.

[0007] Therefore, the frequency is narrowed down to the general consumer and some commercial use areas, and the frequency that can cover most of the uses of those users, that is, fh = 15 to 34 kHz, fv =
Multi-scan display devices that are limited to the range of 50-60Hz are becoming popular.

As shown in FIG. 6, a video source displayed at fh = 15.75 kHz, which is the same horizontal scanning frequency as that of a normal television broadcasting system, includes a television tuner, a satellite broadcasting tuner, a video deck, and a video. Disks, MSX personal computers, personal computers with a resolution of 640 dots × 200 lines or 320 dots × 200 lines, standard captain system terminals, character / multiplex decoders, etc., fh = 2
Video sources displayed at 4kHz include high-density personal computers with a resolution of 640 dots x 400 lines, and video sources displayed at fh = 31.5kHz include high-density captain system terminals, An EDTV decoder etc. are mentioned.

In the multi-scan display device as described above, the scan speed of the input signal source is
From fh = 15.75kHz (normal scan), double fh = 31.
When the scan speed is changed to 5kHz (double scan), if the on-screen display characters displayed during normal scan are not corrected, the aspect ratio of the on-screen display characters will change. . As described above, when the scan speed doubles from normal scan to double scan, the on-screen display characters displayed during normal scan are halved vertically and doubled horizontally. It is displayed in the size of.

FIG. 7 is a diagram showing an example of changes in on-screen display characters when no correction is performed on the on-screen display characters when the scan speed changes from normal scan to double scan.

FIG. 7A shows a display example of the on-screen display character "H" at the time of normal scanning.
(B) shows a display example of the on-screen display character "H" at the time of double scanning. In this way, the size of 1/2 in the vertical direction and double in the horizontal direction is displayed because the oscillation frequency of the dot clock that controls the dot display that constitutes the on-screen display character is
It occurs because it does not change according to the change in scan speed. Therefore, in order to correct the aspect ratio of the on-screen display characters and display them without impairing the quality (always display constant characters regardless of changes in scan speed), the dot display that constitutes the on-screen display characters is The oscillation frequency of the dot clock to be controlled may be changed according to the change in scan speed.

Therefore, as a means for always displaying a constant character irrespective of the change in scan speed, a method of changing the oscillation frequency of the dot clock according to the change in scan speed has been conventionally used. As an example, an OSD-IC (on-screen display-) having different dot clock oscillation frequencies is used.
ICs) are prepared for different scan speeds, and the OSD-ICs are switched and used according to each scan speed.

FIG. 8 is a block diagram showing an example of a conventional on-screen display device having two types of OSD-ICs for normal scanning and double scanning.

As shown in FIG. 8, the conventional on-screen display device includes a signal from a video deck 1 for outputting a normal scan signal, an EDTV decoder 2 for outputting a double scan signal, a video deck 1 or a signal from the EDTV decoder 2. Input selection switch 4, OSD-IC8 for normal scan, OSD-IC9 for double scan, OSD-IC8 or OSD-IC
An RGB switch 10 for selecting any of the on-screen display character data from 9 and a control circuit 3 for controlling the RGB switch 10 based on the scan speed information sent from the input selector switch 4 It is composed of a video processing circuit 5 for synthesizing the incoming signal and the on-screen display character data sent from the RGB switch 10 and a CRT 6 for displaying the signal from the video processing circuit 5 on a display.

Next, the operation of the conventional on-screen display device configured as described above will be described. The input changeover switch 4 which receives the input changeover instruction from the input changeover instruction means (not shown) determines whether the signal of the video deck 1 which outputs the normal scan signal or the signal of the EDTV decoder 2 which outputs the double scan signal, according to the instruction. The selected signal is output to the video processing circuit 5, and the control circuit 3 is notified of the scan speed of the selected signal.

The control circuit 3 uses the OSD-IC 8 that uses the oscillation frequency for normal scanning or the OSD-IC that uses the oscillation frequency for double scanning based on the scan speed information from the input selector switch 4.
It is determined which of the on-screen display character data from 9 is to be selected and the RGB switch 10 is notified. The RGB switch 10 selects either the on-screen display character data from the OSD-IC 8 or the OSD-IC 9 according to an instruction from the control circuit 3, and outputs the selected on-screen display character data to the video processing circuit 5. .

On the other hand, the video processing circuit 5 synthesizes the signal sent from the input changeover switch 4 and the on-screen display character data sent from the RGB switch 10, and converts the signal so that it can be displayed on the CRT 6. Output to CRT6. By the above method, even if the scan speed changes, the quality of the on-screen display characters displayed on the CRT 6 is impaired (the aspect ratio changes).
It is possible to continue to display the on-screen display characters without the need.

FIG. 9 is a block diagram showing another example of a conventional on-screen display device having two types of OSD-ICs for normal scan and double scan.

As shown in FIG. 9, another conventional on-screen display device is a television broadcast receiving antenna 1.
1, a VIF circuit 12 for receiving and selecting a television broadcast and outputting a video signal, an OSD-I for normal scanning
C8, OSD-IC9 for double scan, OSD-I
RGB switch 10, V for selecting either on-screen display character data from C8 or OSD-IC9
A control circuit 13 for controlling the RGB switch 10 based on the scan speed information sent from the IF circuit 12,
It comprises a video processing circuit 5 for synthesizing the signal sent from the VIF circuit 12 and the on-screen display character data sent from the RGB switch 10, and a CRT 6 for displaying the signal from the video processing circuit 5.

Next, the operation of the conventional on-screen display device constructed as above will be described. Now, it is assumed that the television broadcast receiving antenna 11 is receiving a normal television broadcast. Then, when the next program starts and the broadcasting system is switched from normal television broadcasting to broadcasting by EDTV (Clear Vision),
The VIF circuit 12 outputs to the video processing circuit 5 the video signal received by the television broadcasting receiving antenna 11 and selected, and the scan speed is changed with respect to the control circuit 13 (from normal scan to double scan). Notify that it was done. To be precise, the control circuit 13 is notified of the changed scan speed at the timing when the broadcast format is changed to that by the EDTV.

The control circuit 3 that has received the notification is the VIF circuit 1
The oscillation frequency for double scan is used from the on-screen display character data from the OSD-IC8 which uses the oscillation frequency for normal scan that has been selected so far, based on the scan speed information from 2. The RGB switch 10 is notified to select the on-screen display character data from the OSD-IC 9. RGB
The switch 10 is controlled by the control circuit 13 so that the OSD
-IC8 is selectively switched to the on-screen display character data of OSD-IC9, and the newly selected on-screen display character data is output to the video processing circuit 5.

On the other hand, the video processing circuit 5 includes the VIF circuit 1
2 and the video signal sent from 2 and the RGB switch 10
The on-screen display character data sent from the device is synthesized, and at the same time, signal conversion is performed so that the data can be displayed on the CRT 6, and the data is output to the CRT 6. By the above method, even if the scan speed changes, the quality of the on-screen display characters displayed on the CRT 6 is impaired (the aspect ratio changes).
It is possible to continue to display the on-screen display characters without the need.

By the way, according to the above-mentioned conventional method, even if the scan speed of the input signal source changes, the CRT
If the on-screen display characters are continuously displayed without impairing the quality of the on-screen display characters (the aspect ratio changes), two OSD-ICs are used, and the OSD-ICs are used. Also, there has been a problem that the number of parts is increased due to the addition of peripheral circuits related thereto and the cost is increased accordingly. or,
If the conventional on-screen display device is made to correspond to a plurality of video sources having different scan speeds other than the video source according to the conventional example, more OSD-ICs and their related peripheral circuits, etc. There was a problem that it was irrational because it resulted in an increase in the number of parts associated with the expansion of.

[0024]

As described above, according to the conventional method, when the scan speed of the signal source input to the multi-scan display device is changed, the quality of the on-screen display characters displayed on the CRT or the like is improved. If it is attempted to continue to display the on-screen display characters without damaging (changing the aspect ratio), two or more OSD-ICs are required, and the OSD-IC and its related peripheral circuits, etc. There is a problem in that the number of parts is increased due to the expansion and the cost is increased accordingly.

Therefore, the present invention has been made in view of such problems.
Even if the scan speed of the signal source input to the multi-scan display device changes, the OSD-IC and OSD-I
The on-screen display characters displayed on the CRT, etc. are impaired in quality without causing an increase in the number of parts associated with the expansion of C-related peripheral circuits and the like, and the resulting increase in cost (the aspect ratio changes). It is an object of the present invention to provide an on-screen display device capable of continuing to display the on-screen display character without the above.

[0026]

According to another aspect of the present invention, there is provided an on-screen display device comprising: a plurality of input means for inputting a plurality of video sources having different scan speeds; and a desired one of the plurality of video sources. Input signal switching means for selecting a video source and a plurality of font data for on-screen display corresponding to each of a plurality of scan speeds, and on-screen display data based on the font data for on-screen display Detecting the scan speed of the video source selectively switched by the input signal switching means, and determining the font data type corresponding to the detected scan speed by the on-screen display data generating means. To the video signal from the input signal switching means. And a video signal processing means for synthesizing the on-screen display data from the on-screen display data generating means and converting it into a signal displayable on a display, and a display means for displaying the video signal from the video signal processing means on the display. And is provided.

The on-screen display device according to a second aspect of the present invention includes a television signal receiving means for receiving and selecting a television signal input from a television broadcast receiving antenna and converting it into a video signal, and a plurality of scans. An on-screen display data generating means for generating a plurality of on-screen display font data corresponding to each speed and generating on-screen display data based on the on-screen display font data; and the television. Control means for detecting a scan speed of the video signal received from the signal receiving means, and notifying the font data type corresponding to the detected scan speed to the on-screen display data generating means,
Video signal processing means for synthesizing the video signal from the television signal receiving means and the on-screen display data from the on-screen display data generating means to convert into a signal displayable on a display, and the video signal processing means. Display means for displaying the video signal from the display.

An on-screen display device according to a third aspect of the present invention is the on-screen display device according to the first or second aspect, wherein the on-screen display data generating means decodes the command data notified from the control means. A command data decoder, a plurality of on-screen display font data for each of the plurality of scan speeds, and a read-only memory whose addresses are divided into a plurality of areas, and the data of the read-only memory is temporarily stored. And a video RAM for outputting the contents of the video RAM to the video signal processing means, and based on the result decoded by the command data decoder, reads on-screen display font data from the read-only memory. , Said video RA Is temporarily written in the video RAM, the data written in the video RAM is transferred to the output controller, and the on-screen display character data corresponding to the scan speed is output to the video signal processing means via the output controller. And a control circuit for performing such control.

An on-screen display device according to a fourth aspect of the present invention is the on-screen display device according to the first, second or third aspect, wherein the control means includes means for reading a scan speed and means for determining the scan speed. A command output RAM, and means for writing an on-screen display character data selection command according to the scan speed in the command output RAM based on the determination result by the determination means, and the command output RA.
And a means for outputting the on-screen display character data selection command written in M to the on-screen display data generating means.

An on-screen display device according to a fifth aspect of the present invention is the on-screen display device according to any one of the first to fourth aspects, wherein the display means is a device for displaying an input video signal on a display. A multi-scan display device capable of performing multi-scan scanning, comprising a circuit for detecting a scan speed corresponding to the video signal.

An on-screen display device according to a sixth aspect of the present invention is the on-screen display device according to the fifth aspect, wherein the control means detects from the input video signal by a scan speed detection circuit included in the multi-scan display device. The on-screen display data generating means is notified of the font data type corresponding to either one of the selected scan speed or the manually input scan speed by a key operation or the like.

An on-screen display device according to a seventh aspect of the present invention is the on-screen display device according to any one of the first to sixth aspects, wherein the horizontal scanning frequency capable of multi-scan display is in the range of 15 to 34 kHz. The vertical scanning frequency is in the range of 50-60Hz.

[0033]

According to the invention described in claim 1, one of the video sources inputted from the plurality of input means is selected, and the corrected on-screen display corresponding to the scanning speed of the selected video source is selected. From the font data for
Since the on-screen display data generating means generates the on-screen display data based on the font data for the on-screen display, the video source is changed to a video source having another scan speed by the input signal switching means. Even if switched, the quality of the on-screen display characters displayed on the display is not impaired (the aspect ratio is changed).

According to the second aspect of the invention, the on-screen display data generating means is generated from the corrected on-screen display font data corresponding to the scan speed of the television image received by the television broadcasting receiving antenna. Since the on-screen display data based on the on-screen display font data is generated by the above, the scan speed of the television image changes (for example, from the normal broadcasting system to the EDT.
Even when the broadcasting system for V is changed), the quality of the on-screen characters displayed on the display is not impaired (the aspect ratio is changed).

[0035]

EXAMPLES Examples will be described with reference to the drawings.
In the following embodiments, the case where there are two types of scan speeds, normal scan and double scan, will be described. FIG. 1 is a block diagram showing an embodiment of the on-screen display device according to the present invention.

In FIG. 1, an on-screen display device according to an embodiment of the present invention includes a video deck 1 for outputting a normal scan signal, an EDTV decoder 2 for outputting a double scan signal, a video deck 1 or an EDTV.
Input selector switch 4 for selecting one of the signals from the decoder 2 OSD incorporating character pattern font data for normal scan and double scan
Control for outputting a command for causing the OSD-IC 7 to select either font data having a character pattern for normal scan or double scan based on the scan speed information sent from the IC 7 and the input changeover switch 4. The circuit 14, the video processing circuit 5 for synthesizing the signal sent from the input changeover switch 4 and the on-screen display character data sent from the OSD-IC 7, and the CRT 6 for displaying the signal from the video processing circuit 5 on the display ing.

FIG. 2 is a block diagram showing an example of the internal structure of the OSD-IC of the present invention.

As is apparent from FIG. 2, the OSD-IC7
Is a command data decoder 31 and a video RAM 3
2. A ROM 37 storing font data, an output controller 35, and other control circuits 36. The ROM 37 is the ROM 33 and the ROM 34.
The ROM 33 stores font data for normal scanning in the ROM 33, and the font data for double scanning in the ROM 34.

FIG. 3 is a diagram showing an example of font data having character patterns for normal scanning and double scanning.

FIG. 3A shows an example of font data having a character pattern of the on-screen display character "H" at the time of normal scanning.
(B) is the font data with the character pattern of the on-screen display character "H", the aspect ratio of which is corrected so as not to impair the character's quality when displayed on-screen at the scan speed during double scanning. An example is shown respectively. As is clear from the figure, the font data for double scan is twice as large in the vertical direction and half as wide in the horizontal direction as compared with the font data for normal scan. I know that

FIG. 4 is a flow chart showing the control contents performed by the control circuit for the OSD-IC in order to cause the OSD-IC to select font data according to the scan speed.

The operation of the on-screen display device according to the embodiment of the present invention having the above-described structure will be described with reference to FIG. In FIG. 1, the input changeover switch 4 which receives an input changeover instruction from an input changeover instruction means (not shown) determines whether the signal from the video deck 1 which outputs a normal scan signal or the signal from the EDTV decoder 2 which outputs a double scan signal. Select and output the selected signal to the video processing circuit 5, and to the control circuit 14,
The scan speed of the selected signal is notified.
The input selector switch 4 outputs a signal from the currently selected video source to the video processing circuit 5 and the control circuit 1 when the power of the apparatus is turned on.
4 is notified of the scan speed of the selected signal.

The control circuit 14 which has received the notification of the scan speed reads the scan speed information from the input selector switch 4 (step S1), and determines whether or not the scan speed of the switched video source is a double scan signal. Is determined (step S2), if it is a double scan signal, a double scan font data selection command is set in the output RAM of the control circuit 14 (step S4), and if it is a normal scan signal, the control circuit 14 A normal scan font data selection command is set in the output RAM (step S3), and when the setting is completed, the contents of the output RAM are changed to the OSD-IC.
It outputs to 7 (step S5).

The OSD-IC 7 to which the command data from the control circuit 14 is input decodes the command data from the control circuit 14 by the command data decoder 31 in FIG. If the command is a selection command, the content of the normal scan font data is read from the ROM 33 to the video RAM 32, and the content of the video RAM 32 is output to the video processing circuit 5 via the output controller 35. It If the command is a double scan font data selection command,
R that stores font data for double scan
The contents are read from the OM 34 to the video RAM 32, and the contents of the video RAM 32 are output to the video processing circuit 5 via the output controller 35.

On the other hand, the video processing circuit 5 synthesizes the signal sent from the input selector switch 4 and the on-screen display character data sent from the RGB switch 10 and, at the same time, converts the signal so that it can be displayed on the CRT 6. After that, output to CRT6. In this embodiment, the control circuit 1
4 determines whether or not the scan speed is a double scan signal based on the scan speed information notified from the input selector switch 4. The scan speed information is externally read by a keyboard or remote controller. May be manually input from a CRT
When 6 is composed of a multi-scan display device, it may be detected from the video signal input to the multi-scan display device by the scan speed detection circuit of the multi-scan display device.

By the above method, even if the scan speed changes, the on-screen display characters can be continuously displayed without impairing the quality of the on-screen display characters displayed on the CRT 6 (the aspect ratio changes). it can.

FIG. 5 is a block diagram showing another embodiment of the on-screen display device according to the present invention.

In FIG. 5, an on-screen display device according to another embodiment of the present invention includes an antenna 11 for receiving a television broadcast, a VIF circuit 12 for receiving and selecting a television broadcast, and outputting a video signal, a normal circuit. OSD-IC 16 having font data of character patterns for scanning and double scanning, OSD based on scan speed information sent from VIF circuit 12
A control circuit 14 for outputting a command for causing the IC 16 to select either font data of a character pattern for normal scan or double scan,
Signal sent from VIF circuit 12 and OSD-IC
A video processing circuit 5 for synthesizing on-screen display character data sent from 12 and a CRT 6 for displaying a signal from the video processing circuit 5 on a display.

Next, the operation of the on-screen display device which is another embodiment of the present invention having the above structure will be described with reference to FIG.

It is now assumed that the television broadcast receiving antenna 11 shown in FIG. 5 is receiving normal television broadcast. Then, if the program up to this point ends and the next program starts and the normal television broadcasting system is switched to the broadcasting system by EDTV (Clear Vision), the VIF circuit 12 uses the television broadcasting receiving antenna 11. The control circuit 14 is informed that the scan speed is changed (from normal scan to double scan) as the video signal, which is the video source that has been received, tuned and converted into a video signal, is output to the video processing circuit 5. To notify you. To be precise, the changed scan speed is notified to the control circuit 14 at the timing when the broadcast system is changed to that by the EDTV. The VIF circuit 12
When the power of the apparatus is turned on, for example, the broadcasting format is unconditionally switched, that is, the scanning speed is changed.

Upon receiving the notification, the control circuit 14 reads the scan speed information from the VIF circuit 12 (step S1), and determines whether or not the scan speed of the switched video source is a double scan signal. (Step S2) If it is a double scan signal, a double scan font data selection command is set in the output RAM of the control circuit 14 (step S4). If it is a normal scan signal, the output RA of the control circuit 14 is output.
A normal scan font data selection command is set in M (step S3), and when the setting is completed, the contents of the output RAM are output to the OSD-IC 16 (step S5).

The OSD-IC 16 to which the command data from the control circuit 14 has been input decodes the command data from the control circuit 14 by the command data decoder 31 in FIG. If it is a selection command, the contents are read from the ROM 33 in which the font data for normal scan is stored to the video RAM 32, and the contents of the video RAM 32 are output to the video processing circuit 5 via the output controller 35. If the command is a double scan font data selection command,
R that stores font data for double scan
The content is read from the OM 34 to the video RAM 32, and the content of the video RAM 32 is output to the video processing circuit 5 via the output controller 35.

On the other hand, the video processing circuit 5 includes the VIF circuit 1
After the signal sent from 2 and the on-screen display character data sent from the RGB switch 10 are combined, the signal is converted so that it can be displayed on the CRT 6 and then C
Output to RT6. In this embodiment, the control circuit 14
Determines whether or not the scan speed is a double scan signal based on the scan speed information notified from the VIF circuit 12, but the scan speed information is manually input from the outside using a keyboard, a remote controller, or the like. The video signal input to the multi-scan display device by the scan speed detection circuit of the multi-scan display device when the CRT 6 is composed of the multi-scan display device. It may be one detected from.

By the above method, even if the scan speed changes, the on-screen display characters can be continuously displayed without impairing the quality of the on-screen display characters displayed on the CRT 6 (the aspect ratio changes). it can.

In the above embodiment, the scan speed is either normal scan or double scan, that is, the horizontal scan frequency fh is 15.75 kHz or 31.5 kHz. However, the present invention is not limited to this. However, it can be applied to various video sources other than the above.

[0056]

As described above, according to the on-screen display device of the present invention, the OSD-IC (on-screen) having different oscillation frequencies of the dot clock required when the scan speed of the input video source is changed.・ Screen display-IC) does not need to be prepared for different scan speeds, so that the number of parts and the resulting increase in cost are not caused, and
Even if the scan speed of the input video source changes, the on-screen display characters can be displayed on the display without impairing the quality of the on-screen display characters (changing the aspect ratio).

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an on-screen display device according to the present invention.

FIG. 2 is a block diagram showing an example of an internal configuration of an OSD-IC of the present invention.

FIG. 3 is a diagram showing an example of font data having character patterns for normal scanning and double scanning.

[Figure 4] Font data corresponding to scan speed
In order to make SD-IC select, the control circuit is OSD-IC
The flowchart which showed the control content performed with respect to.

FIG. 5 is a block diagram showing another embodiment of the on-screen display device according to the present invention.

FIG. 6 is a diagram showing a multi-scan display device and various video sources.

FIG. 7 is a diagram showing an example of changes in on-screen display characters when no correction is performed on the on-screen display characters when the scan speed changes from normal scan to double scan.

FIG. 8 is a block diagram showing an example of a conventional on-screen display device having two types of OSD-ICs for normal scanning and double scanning.

FIG. 9 is a block diagram showing another example of a conventional on-screen display device having two types of OSD-ICs for normal scan and double scan.

[Explanation of symbols]

 1 ... Video deck 2 ... EDTV decoder 4 ... Input selector switch 5 ... Video processing circuit 6 ... CRT 7 ... OSD-IC 14 ... Control circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 5/66 D

Claims (7)

[Claims] 1. A plurality of input means for inputting signals from a plurality of video sources having different scan speeds, an input signal switching means for selecting a desired video source from the plurality of video sources, and a plurality of scans. It has font data for multiple on-screen displays corresponding to each speed,
On-screen display data generating means for generating on-screen display data based on the font data for on-screen display, and a scan speed detected by detecting the scan speed of the video source selectively switched by the input signal switching means. The control means for notifying the on-screen display data generating means of the font data type corresponding to the above, the video signal from the input signal switching means, and the on-screen display data from the on-screen display data generating means are combined. An on-screen display device comprising: a video signal processing means for converting into a signal displayable on a display and a display means for displaying a video signal from the video signal processing means on a display. 2. A television signal receiving means for receiving and selecting a television signal input from a television broadcasting receiving antenna and converting it into a video signal, and a plurality of on-screens respectively corresponding to a plurality of scan speeds. Has font data for display,
On-screen display data generating means for generating on-screen display data based on the on-screen display font data, and a scan speed detected by detecting a scan speed of the video signal received from the television signal receiving means. The control means for notifying the on-screen display data generating means of the font data type corresponding to the above, the video signal from the television signal receiving means, and the on-screen display data from the on-screen display data generating means are combined. An on-screen display device comprising: a video signal processing means for converting the video signal into a signal displayable on a display; and a display means for displaying the video signal from the video signal processing means on the display. 3. The on-screen display data generating means stores a command data decoder for decoding the command data notified from the control means, and a plurality of on-screen display font data for each of the plurality of scan speeds. A read-only memory whose addresses are divided into a plurality of areas, a video RAM for temporarily storing the data in the read-only memory, an output controller for outputting the contents of the video RAM to the video signal processing means, On-screen display font data is read from the read-only memory based on the result decoded by the command data decoder, and the video RA
The data written in the video RAM is transferred to the output controller, and the on-screen display character data corresponding to the scan speed is output to the video signal processing means via the output controller. 3. The on-screen display device according to claim 1, wherein the on-screen display device is configured with a control circuit for performing control. 4. The on-screen display according to the scan speed based on the determination result by the control means, a means for reading the scan speed, a means for determining the scan speed, a RAM for command output, and the determining means. And a means for writing the character data selection command in the command output RAM, and a means for outputting the on-screen display character data selection command written in the command output RAM to the on-screen display data generating means. The on-screen display device according to claim 1, wherein the on-screen display device is a display device. 5. The display means is a device for displaying an input video signal on a display, and is a multi-scan display device capable of multi-scan scanning, comprising a circuit for detecting a scan speed corresponding to the video signal. 5. The on-screen display device according to claim 1, wherein the on-screen display device is a display device. 6. The control means is any one of a scan speed detected from an input video signal by a scan speed detection circuit included in the multi-scan display device or a scan speed manually input by a key operation or the like. The on-screen display device according to claim 5, wherein the font data type corresponding to is notified to the on-screen display data generating means. 7. A horizontal scanning frequency capable of multi-scan display is in the range of 15 to 34 kHz, and a vertical scanning frequency is 50 to 34 kHz.
7. The on-screen display device according to claim 1, wherein the on-screen display device has a frequency range of 60 Hz.