JPH11119765A - Video signal converter - Google Patents

Abstract

(57) [Problem] To provide a video signal conversion device for converting a video signal for generating a color image so as to conform to characteristics of a monitor device. SOLUTION: A memory means 15b for storing a digital signal for generating an image for each dot constituting one unit of an image, and one dot of the digital signal stored in the memory means 15b is stored in a horizontal direction and a vertical direction. An image conversion means 17 converts the digital signal into a plurality of dots, and an addition means 18a adds horizontal and vertical synchronization signals of a predetermined period to the digital signal converted by the image conversion means 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal conversion device for converting a video signal constituting an image so as to conform to the characteristics of a monitor device when displaying an output of a terminal device or the like as an image.

[0002]

2. Description of the Related Art Conventionally, when an output of a terminal device such as a personal computer is displayed as, for example, a color image, a monitor device is connected to the terminal device. And the display of the monitor device,
For example, a method of imaging an output on a screen of a cathode ray tube has been adopted. However, the quality of the monitor has been improved,
The number of pixels of the display, that is, the resolution is rapidly improving.
In such a case, if the number of pixels in the horizontal direction and the vertical direction of the video signal output from the terminal device is still small as before, the difference between the number of pixels of the video signal and the resolution of the monitor device increases, Display that makes use of the characteristics of a good monitor device cannot be performed.

Here, an example of an output image displayed on the screen of a display device when the number of pixels of a video signal output from a terminal device such as a personal computer is different from the resolution of the display device of the monitor device is shown. 4 and FIG.

FIG. 4A shows a case where the number of pixels of a video signal output from a terminal device is, for example, 672 dots in the horizontal direction and 336 dots in the vertical direction. The same as the number of pixels of the video signal 67
This is an example of display on a screen 41 of a 2-dot, 336-dot display. In this case, the output image A is visualized on the entire screen 41 of the monitor device as shown by the diagonal lines.

FIG. 4B shows a video signal having the above-mentioned structure displayed on a screen 42 of a monitor device having the same size and a resolution of 1280 dots in the horizontal direction and 1024 dots in the vertical direction. It is an example. In this case, the output image A is reduced and displayed in a partial area of the screen 42 of the monitor device, and the screen 42 of the monitor device is not effectively used. At this time, the characters displayed on the screen 42 are small and difficult to see.

FIG. 5A shows the same display example as FIG. 4A, and FIG. 5B shows a screen resolution of 1280 dots in the horizontal direction and 1024 dots in the vertical direction. Is an example displayed on the screen 51 of the monitor device having a large size.

In this case as well, the output image A is displayed only in a partial area on the screen 51 of the monitor device as shown by the diagonal lines, and the screen 51 of the monitor device is not used effectively.

[0008]

As described above, when the difference between the number of pixels of a video signal output from a terminal device such as a personal computer and the resolution of the monitor device becomes large, the output is performed only to a partial area on the screen of the monitor device. The image will be displayed. For this reason, there is a problem that characters are displayed small or an unnatural screen is generated, and an output image utilizing a display screen of a monitor device with improved resolution cannot be generated.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a video signal conversion device for converting a video signal for generating an image so as to conform to the characteristics of a monitor device.

[0010]

A video signal converter according to the present invention comprises an A / D converter for converting an analog signal constituting an image into a digital signal, and a digital signal converted by the A / D converter. Memory means for storing image data, image conversion means for converting the image data stored in the memory means into a digital signal suitable for both a horizontal direction and a vertical direction of a monitor device as an output destination; D / A conversion means for converting the digital signal converted by the image conversion means into an analog signal, and addition means for adding a synchronization signal of a predetermined period to the analog signal converted by the D / A conversion means. ing.

Further, the video signal conversion apparatus of the present invention converts an analog signal constituting an image into a digital signal.
/ D converting means, a memory means for storing the digital signal converted by the A / D converting means, and one dot of the digital signal stored in the memory means is provided in at least one of a horizontal direction and a vertical direction. Image conversion means for converting an image into a digital signal occupying a plurality of dots;
D / A conversion means for converting the digital signal converted by the image conversion means into an analog signal, and addition means for adding a synchronization signal of a predetermined period to the analog signal converted by the D / A conversion means. doing.

According to the above arrangement, the digital signal constituting the image is stored in the memory means for each dot constituting one unit of the image, for example. Then, one dot of the digital color signal stored in the memory means is image-converted so as to occupy a plurality of dots in both the horizontal and vertical directions, or a plurality of dots are converted in at least one of the horizontal and vertical directions. The image is converted to occupy the dots. In this case, both horizontal and vertical directions, or at least one of them
The number of pixels can be increased in one direction. Therefore, the display screen of the monitor device with improved resolution is wide,
Then, an output image that is effectively utilized can be obtained. Further, after the image conversion, a synchronization signal having a frequency corresponding to the operation of the monitor device is added, so that the image can be reliably formed on the screen of the monitor device.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the circuit diagram of FIG. Reference numeral 11 denotes a terminal device such as a personal computer. From the terminal device 11,
By scanning in the horizontal and vertical directions, for example, analog signals of a plurality of colors for generating a color image are output. The analog signals of a plurality of colors are, for example, a red signal R, a green signal G, and a blue signal B, and a synchronization signal S is added separately from the color signals R, G, and B. The synchronizing signal S includes a horizontal synchronizing signal and a vertical synchronizing signal. In the drawing, the horizontal synchronizing signal and the vertical synchronizing signal are displayed as a synchronizing signal S together. The color signals R, G, B and the synchronization signal S output from the terminal device 11 are input to the A / D converter 12. A /
In the D converter 12, the color signals R, G, B and the synchronization signal S are converted into serial digital signals, respectively.
Then, it is input to the input signal converter 13.

The input signal converter 13 comprises a serial-parallel converter 13a and an input signal controller 13b. Each color signal R input to the input signal conversion unit 13,
G and B are output from the serial-parallel converter 13a.
Under the control of the input signal control unit 13b, the signal is converted into a parallel signal composed of a plurality of bits. At this time, the synchronization signal S is separated.

Each of the color signals R converted into parallel signals,
G and B are input to the video signal control unit 15 via the data line DL and the transceiver 14.

The video signal control section 15 comprises a CRT controller 15a and a video memory 15b. Each of the color signals R, G, and B input to the video signal control unit 15 has a CR
It is stored in the video memory 15b under the control of the T controller 15a.

The control by the input signal control unit 13b in the input signal conversion unit 13 and the control by the CRT controller 15a in the video signal control unit 15 are controlled by the control controller unit 16, respectively. The controller 16 includes, for example, a microprocessor 16a and a memory 16b. The memory 16b stores control programs used for control by the input signal controller 13b and control by the CRT controller 15a. Have been. The control program is called under the control of the microprocessor 16a, and is supplied to the input signal conversion unit 13 and the video signal control unit 15 through the address line AL.

The state of each color signal R, G, B stored in the video memory 15b is schematically shown in FIG.
It is like. The horizontal direction H in FIG. 2 corresponds to a horizontal scanning direction (arrow H1) when a color image is generated, and the vertical direction V corresponds to a vertical scanning direction (arrow V1). When the number of pixels in the horizontal direction of the color signal converted into the digital signal is 672 dots, and the number of pixels in the vertical direction is 336 dots, 672 dots in the horizontal direction and 336 dots in the vertical direction are provided. The dots are saved.
When the storage of the color signal for one screen is completed, the lower right dot returns to the upper left dot as indicated by an arrow Y, and the storage of the color signal for the next screen is started.

The video memory 15b stores the respective color signals R,
G and B are stored in separate areas. But,
Each of the color signals R, G, and B has the same storage state, and FIG. 2 shows one of them.

Thereafter, the respective color signals R, G, B stored in the video memory 15b are read under the control of the CRT controller 15a and supplied to the image converter 17. The image conversion unit 17 performs image conversion of each of the color signals R, G, and B according to the resolution of a monitor device that displays a video signal.
Here, the resolution of the monitor device is, for example, 12 in the horizontal direction.
The operation of image conversion in the image conversion unit 17 will be described with reference to FIG. 3, taking the case of 80 dots and 1024 dots in the vertical direction as an example. The image conversion in the image conversion unit 17 is performed separately for each of the color signals R, G, and B, but is performed in the same manner for each of the color signals R, G, and B. Therefore, only one of them will be described here.

In this case, the resolution in the horizontal direction of the monitor device is almost twice the number of pixels of the video signal, and the resolution in the vertical direction is almost three times the number of pixels of the video signal.
Accordingly, in the image conversion unit 17, the dots constituting one unit of the image in the original color signal, for example, the pixel D11 in FIG.
Are read out repeatedly so that the color signal of the first color occupies twice the number of dots in the horizontal scanning direction (arrow H1) and three times the number of dots in the vertical direction (arrow V1), and symbols D1 to D6 in FIG. As shown by, the signal is converted into a signal for 6 dots. Then, such image conversion is performed for all the pixels in FIG. When the image conversion of one screen is completed, the image returns to the upper left dot as indicated by arrow Y, and the image conversion for the color signal of the next screen is started.

Therefore, when the image conversion of one screen is completed, the horizontal direction is 672 × 2 = 13 as shown in FIG.
The image is converted to a color signal of 44 dots and 336 × 3 = 1008 dots in the vertical direction. Then, the image-converted color signals are input to the output signal converter 18.

The output signal converter 18 is provided with the synchronous signal switch 1
8a, parallel-serial converter 18b, synchronization signal source 1
8c and the like. The color signal input from the image conversion unit 17 to the output signal conversion unit 18 is converted into a serial signal by a parallel-serial converter 18b. Then, the color signal converted into the serial signal is converted into a D / A signal at the next stage.
The signal is input to the converter 19 and converted into an analog signal.

The synchronous signal switch 18a switches to a synchronous signal from a synchronous signal source 18c added to the color signal image-converted by the image converter 17. The synchronization signal S includes a horizontal synchronization signal and a vertical synchronization signal. These synchronizing signals are set to have frequencies corresponding to the horizontal and vertical scanning speeds of a monitor device that generates a color image, and are applied to the D / A converter 19. And
A synchronization signal S is added to the color signals R, G, and B converted to analog signals.

The color signals R, G, and B, which have been converted into analog signals and to which the synchronization signal S has been added, are input to the monitor device 20, and are generated as color output images on the screen of the display.

In the above configuration, the color signals R, G,
When the synchronization signal S is added to B, it is added as an independent system, for example, separately from the system of the color signals R, G, and B.
However, one of the color signals R, G, B, for example, the green signal G
It can also be added in the form of being included in.

In the case of the above embodiment, the image conversion unit 17
, The horizontal direction is 1344 dots, and the vertical direction is 10
It is converted into a color signal of the number of pixels of 08 dots. On the other hand, the resolution of the monitor device is, for example, 1280 dots in the horizontal direction and 1024 dots in the vertical direction. As described above, even if there is a slight difference between the number of pixels converted by the image conversion unit 17 and the resolution of the monitor device, such a difference can be adjusted by the function of the monitor device 20, so that no problem occurs.

In the above embodiment, the conversion of one screen has been described. But in the real case,
Since the screens are continuously transmitted, the above-described operation is repeatedly performed for each screen.

In the above embodiment, the image converter 17 converts the color signal of each pixel into double dots in the horizontal direction and triples the dots in the vertical direction. ing. However, this number is only an example, and the number of dots to be converted into one dot in the horizontal and vertical directions is determined in consideration of the number of pixels of the video signal output from the terminal device and the resolution of the monitor device. Is determined as appropriate. Although the number of dots is increased in both the horizontal and vertical directions, if the resolution of the monitor is increased in only one of the horizontal and vertical directions, only the number of dots in the increased direction is reduced. Will increase. Further, although the description has been made of the example of a color image, the present invention can be applied to a monochrome image.

[0030]

According to the present invention, it is possible to realize a video signal converter for converting a video signal for generating an image so as to conform to the characteristics of a monitor device.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 4 is a diagram for explaining a conventional example.

FIG. 5 is a diagram for explaining a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Terminal device 12 ... A / D converter 13 ... Input signal conversion part 13a ... Serial-parallel converter 13b ... Input signal control part 14 ... Data bus and transceiver 15 ... Video signal control part 15a ... CRT controller 15b ... Video memory Reference Signs List 16 Control controller 16a Microprocessor 16b Memory 17 Image converter 18 Output signal converter 18a Synchronous signal switch 18b Parallel-serial converter 18c Synchronous signal source 19 D / A converter 20 … Monitoring device

Claims (2)

[Claims] An A / D converter for converting an analog signal constituting an image into a digital signal, a memory for storing the digital signal converted by the A / D converter as image data, and a memory for storing the digital signal. Image conversion means for converting the stored image data into a digital signal suitable for both the horizontal direction and the vertical direction of the output monitor, and converting the digital signal converted by the image conversion means into an analog signal D / A conversion means for converting,
A video signal conversion device comprising: an addition unit that adds a synchronization signal having a predetermined period to the analog signal converted by the D / A conversion unit. 2. A / D conversion means for converting an analog signal constituting an image into a digital signal, a memory means for storing the digital signal converted by the A / D conversion means,
Image converting means for converting an image into a digital signal in which one dot of the digital signal stored in the memory means occupies a plurality of dots in at least one of a horizontal direction and a vertical direction; and D / A conversion means for converting a digital signal into an analog signal;
A video signal conversion device comprising: an addition unit that adds a synchronization signal having a predetermined period to the analog signal converted by the D / A conversion unit.