JPH06138834A - Display device - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if a horizontal fixed scan display is used, which is easy to enhance the performance and reliability of a CRT type display for video signals of various standards such as computers,
An object of the present invention is to provide a display device in which the number of display lines of an input video signal is not lost and the vertical image quality is not deteriorated. [Configuration] Generates a fixed frequency output horizontal sync signal,
The clock signal 25 on the reading side is appropriately reproduced so that the dots in the horizontal direction are displayed as they are, and the output vertical synchronization signal is reproduced so as to be output as it is without performing interpolation calculation of the vertical line or output by enlarging it to an integral multiple. By using a scan converter, video signals of various standards such as a computer are displayed on the display 28 of horizontal fixed scan and vertical variable scan without deterioration of image quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying video signals of various standards such as a computer.

[0002]

2. Description of the Related Art In recent years, video media have been diversified, and video signals of various standards such as televisions, high-definition televisions, personal computers and workstations exist. Since these video signals differ in horizontal scanning frequency, vertical scanning frequency, number of display dots, aspect ratio, etc., generally, dedicated displays are required for each.

On the other hand, in response to the demand for displaying various video signals on one display at conferences, exhibitions, presentations, etc., a CRT type (direct view type, projection type) display is a variable scan display. There is. However, the variable scan display must support multi-frequency, centered on the analog deflection circuit, and it is difficult to achieve the best performance for all the frequencies that it wants to support, and in terms of reliability design. Is also the same. (In particular, it is difficult to realize variable scanning with respect to the horizontal scanning frequency.) As a method for solving such a problem, a scan in which a video signal is digitally processed and converted into a signal having a desired horizontal scanning frequency and vertical scanning frequency There is a method using a converter.

Conventionally, referring to the drawings, video signals of various standards such as a computer are displayed on a fixed scan display corresponding to a fixed horizontal scanning frequency and a fixed vertical scanning frequency by using a scan converter. The display device will be described.

FIG. 3 shows an example of a schematic structure thereof. In FIG. 3, reference numeral 51 is an input video signal, 52 is an input synchronizing signal, 53 is a scan converter, 54 is an A / D converter, 55 is an interpolation calculation (reduction) processing unit, 56 is a memory, and 57 is an interpolation calculation (enlargement). Processing unit, 58 is a D / A converter, 59 is a writing-side clock signal reproducing unit, 60 is a writing-side clock signal, 61 is an interpolation calculation control unit, 62 is a reading-side clock signal reproducing unit, and 63 is a horizontal synchronizing signal. Generator 64, vertical synchronizing signal generator 65, read-side clock signal 66, output video signal 67, output synchronizing signal 68, fixed horizontal scanning frequency, fixed scan display corresponding to fixed vertical scanning frequency Is.

A video signal of a computer or the like contains frequency components higher than the dot clock frequency that constitutes the screen, and in terms of image quality, sampling with the dot clock signal is required for A / D conversion. desirable. The input video signal 51 is converted by the scan converter 53 as follows.

First, the writing side clock signal 60 is input from the input synchronizing signal 52 to the writing side clock signal reproducing section 59.
Is reproduced and the input video signal 51 is sampled by the A / D converter 54. When the number of display dots and the number of lines are reduced (reduced), the interpolation calculation (for reduction) processing unit 55 performs the interpolation calculation process and writes it in the memory 56. To increase (enlarge) the number of display dots and lines, the memory 5
After reading from 6, the interpolation calculation (for enlargement) processing unit 57
Performs interpolation calculation processing. At that time, the interpolation calculation processing is controlled by the interpolation calculation control unit 61. Further, the read-side clock signal 65 is reproduced from the horizontal sync signal having a fixed frequency generated by the horizontal sync signal generator 63 in accordance with the number of dots displayed in the fixed one horizontal scanning period. It is reproduced in the part 62. And D / A
The converter 58 generates the output video signal 66, and further outputs the output synchronizing signal 67 including the vertical synchronizing signal having a fixed frequency generated by the vertical synchronizing signal generator 64.

The output video signal 66 and the output synchronizing signal 67 converted as described above are input to a fixed scan display 68 corresponding to a fixed horizontal scanning frequency and a fixed vertical scanning frequency and displayed.

In the display device for a video signal such as a computer configured as described above, in the horizontal direction, the input video signal 51 is A / D converted using the dot clock signal, written in the memory 56, and interpolation calculation is performed. D / A conversion of the digital data as it is does not cause deterioration of the image quality basically, and the adjustment of the display aspect (horizontal direction) is made variable by changing the read-side clock signal 65 to make the raster horizontal. It can be realized with the amplitude fixed.

[0010]

However, in the above-described conventional method, the number of lines displayed in one vertical scanning period is fixed in the vertical direction due to the fixed horizontal scanning frequency and the fixed vertical frequency. , Input video signal line-by-line data as it is without interpolation calculation (1x)
If the number of input lines is less than the number of output lines, there is no deterioration in image quality, but it is displayed vertically in the screen (raster) in a small size, or the number of input lines is output. If the number of lines is larger than the number of lines, some lines may not be displayed and may not be displayed.In addition, the adjustment of the display aspect is not sufficient only with the adjustment of the horizontal read side clock signal.
The vertical amplitude of the raster will have to be changed significantly.

Then, in order to output the entire vertical screen of the input video signal to a fixed number of display lines while also fixing the vertical amplitude of the raster and taking the display aspect into consideration, interpolation calculation processing between lines in the vertical direction (arbitrary) is performed. (Reduction of magnification, enlargement)
However, there is a problem in that the image quality is deteriorated (however, in the case of integer multiple expansion, there is basically no deterioration in image quality).

The present invention solves the above-mentioned problems of the prior art. Even if a fixed horizontal scanning frequency compatible display is used, which is easy to enhance the performance and reliability of a CRT type display, the number of display lines of an input video signal is used. It is an object of the present invention to provide a display device that does not lose its image quality and does not deteriorate the vertical image quality.

[0013]

In order to achieve this object, the display device of the present invention has a writing side clock signal reproducing section for reproducing a writing side clock signal from an input synchronizing signal, and an A for sampling an input video signal. / D converter,
A memory that stores the output of the A / D converter, an integer multiple control unit that controls how much the input synchronization signal is multiplied by an integer in the vertical direction, and a horizontal synchronization signal generation unit that generates the horizontal synchronization signal of the fixed frequency output. And a read-side clock signal reproducing section for reproducing the read-side clock signal from the output horizontal sync signal, a vertical sync control section for controlling the frequency of the output vertical sync signal, and a vertical sync signal under the control of the vertical sync control section. , A vertical synchronization signal reproducing unit for reproducing the data, an integer multiple processing unit for vertically multiplying the output of the memory by an integer under the control of the integer multiple control unit, and a D / A for D / A converting the output of the integer multiple processing unit. A scan converter having a converter, an output of the scan converter, that is, an output video signal of the D / A converter, and a horizontal sync signal generator and a vertical sync signal reproducer. A video signal of various standards such as a computer, which is composed of a display compatible with a fixed horizontal scanning frequency and which receives a power synchronization signal as an input, and by appropriately controlling the frequencies of the clock signal and the vertical synchronization signal on the reading side It can be displayed without deterioration.

[0014]

With this configuration, even when a video signal of various standards such as a computer is input, a display for a fixed horizontal scanning frequency that can easily improve the performance and reliability of a CRT type display is displayed. It is possible to display without losing the number of lines and without deteriorating the image quality in the vertical direction.

[0015]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic structure of this embodiment. In FIG. 1, 11 is an input video signal, 12 is an input synchronizing signal, 13 is a scan converter, and 14 is A /
D converter, 15 is a memory, 16 is an integer multiple processing unit, 17 is a D / A converter, 18 is a writing side clock signal reproducing unit,
19 is a write-side clock signal, 20 is an integer multiple control unit,
Reference numeral 21 is a vertical synchronization control unit, 22 is a read side clock signal reproduction unit, 23 is a horizontal synchronization signal generation unit, 24 is a vertical synchronization signal reproduction unit, 25 is a read side clock signal, 26 is an output video signal, and 27 is an output synchronization signal. 28 are horizontal fixed scan and vertical variable scan displays.

The operation of the display device configured as described above will be described. As shown in FIG. 1, the writing-side clock signal reproducing unit 18 reproduces the writing-side clock signal 19 from the input synchronization signal 12, and the input video signal 1
1 is sampled by the A / D converter 14 and written in the memory 15. Further, the read-side clock signal 25 is reproduced from the horizontal sync signal having a fixed frequency generated by the horizontal sync signal generator 23 in accordance with the number of dots displayed in the fixed one horizontal scanning period. It is reproduced in the section 22. The output vertical synchronizing signal is reproduced by the vertical synchronizing signal reproducing unit 24 under the control of the vertical synchronizing control unit 21 so that all the display lines of the input video signal 12 can be output. At this time, the number of lines of the input video signal 11 is small,
When the frequency of the output synchronization signal becomes too high, the integer multiple control unit 20 controls the digital data read from the memory 15 by the integer multiple control unit 16 in the vertical direction by an integer multiple (write twice, Display three times, etc. (1 in normal operation)
The frequency of the vertical sync signal. And D /
The A converter 17 generates the output video signal 26 and further outputs the output synchronizing signal 27.

The output video signal 26 and the output synchronizing signal 27 converted as described above are input to the display 28 for horizontal fixed scan and vertical variable scan for display.

With this configuration, even if a video signal of various standards such as a computer is input using a fixed horizontal scanning frequency compatible display that easily enhances the performance and reliability of the CRT type display, The number of display lines of the video signal is not lacking, and the vertical image quality can be displayed without deterioration.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a schematic structure of this embodiment. In FIG. 2, 31 is an input video signal, 32 is an input synchronizing signal, 33 is a scan converter, and 34 is A /
D converter, 35 is a memory, 36 is an integer multiple processing unit, 37 is a D / A converter, 38 is a writing side clock signal reproducing unit,
39 is a write-side clock signal, 40 is an integer multiple control unit,
41 is a vertical synchronization selection unit, 42 is a read side clock signal reproduction unit, 43 is a horizontal synchronization signal generation unit, 44 is a vertical synchronization signal generation unit, 45 is a read side clock signal, 46 is an output video signal, and 47 is an output synchronization signal. Reference numerals 48 denote horizontal fixed scan and vertical switching scan displays.

Generally, in a CRT type display, vertical multi-frequency correspondence is relatively easier to realize than horizontal multi-frequency correspondence, but still high performance in a corresponding wide frequency range (for example, 30 to 150 Hz). It is difficult to realize the above, and the actual circuit configuration is also switched depending on the frequency range (for example, 30 to 50, 5
0-80, 80-110, 110-150 Hz, etc.) and so on. The display 38 of this embodiment has only a few fixed vertical frequencies (for example, 4
It is possible to achieve higher performance in a vertical switching scan display corresponding to 0, 60, 90, 120 Hz, etc.) at several corresponding fixed vertical frequencies.

The operation of the display device configured as above will be described. As shown in FIG. 2, the writing-side clock signal reproducing unit 38 reproduces the writing-side clock signal 39 from the input synchronizing signal 32, and the input video signal 3
1 is sampled by the A / D converter 34 and written in the memory 35. Further, the read-side clock signal 45 is reproduced from the horizontal sync signal having a fixed frequency generated by the horizontal sync signal generator 43 in accordance with the number of dots displayed in the fixed one horizontal scanning period. It is reproduced in the section 42. As the output vertical synchronizing signal, the vertical synchronizing selecting unit 41 can output all the display lines of the input video signal 32 and display the input video signal 32 in the raster as large as possible.
The vertical frequency is selected by and is generated by the vertical synchronizing signal generator 44. At this time, as in the case of the previous embodiment, under the control of the integer multiple control unit 40, the digital data read from the memory 35 is vertically multiplied by an integer multiple (2 degrees) by the integer multiple control unit 36 as necessary. Writing, triple writing, etc.) (1x in normal operation) and output video signal 4 at D / A converter 37
6 is generated, and the output synchronization signal 47 is further output.

The output video signal 46 and the output synchronizing signal 47 converted as described above are input to the display 48 for horizontal fixed scan and vertical switching scan (corresponding to several types of frequencies with high performance) and displayed.

With such a configuration, a CRT type display capable of a fixed horizontal scanning frequency which easily improves the performance and reliability, and a switching scanning display which can easily improve the vertical scanning frequency more than the variable scanning are used. Considering the display aspect, the display raster will be slightly smaller than in the case of vertical variable scan, but even if video signals of various standards such as computers are input,
The number of display lines of the input video signal is not lost, and the vertical image quality can be displayed without deterioration.

[0026]

As described above, according to the present invention, the writing side clock signal reproducing section for reproducing the writing side clock signal from the input synchronizing signal, the A / D converter for sampling the input video signal, and the A / D conversion. A memory that stores the output of the instrument, an integer multiple control unit that controls how many times the input synchronization signal is multiplied by an integer in the vertical direction, a horizontal synchronization signal generation unit that generates a horizontal synchronization signal with a fixed frequency output, and an output A read-side clock signal reproduction unit that reproduces the read-side clock signal from the horizontal synchronization signal, a vertical synchronization control unit that controls the frequency of the output vertical synchronization signal, and a vertical reproduction unit that reproduces the vertical synchronization signal under the control of the vertical synchronization control unit. A synchronization signal reproducing unit, an integer multiple processing unit for vertically multiplying the output of the memory under control of the integer multiple control unit, and a D / A conversion for D / A converting the output of the integer multiple processing unit. And a scan converter with a door,
The output of the scan converter, that is, the D / A
Input of video signals of various standards such as a computer, which is composed of a horizontal fixed scan display which receives the output video signal of the converter and the output sync signal of the horizontal sync signal generator and the vertical sync signal reproducer. On the other hand, by appropriately controlling the frequencies of the clock signal and the vertical synchronizing signal on the read side, a horizontal fixed scan display that easily enhances the performance and reliability of the CRT type display is used, and the number of display lines of the input video signal is reduced. It is possible to display without any loss of quality in the vertical direction.

[Brief description of drawings]

FIG. 1 is a schematic block configuration diagram of a display device according to an embodiment of the present invention.

FIG. 2 is a schematic block configuration diagram of a display device according to a second embodiment of the present invention.

FIG. 3 is a schematic block configuration diagram of a conventional display device.

[Explanation of symbols]

11 Input Video Signal 12 Input Synchronization Signal 13 Scan Converter 14 A / D Converter 15 Memory 16 Integer Multiple Processing Unit 17 D / A Converter 18 Write-side Clock Signal Reproducing Unit 19 Write-side Clock Signal 20 Integer Multiple Control Unit 21 Vertical Synchronization Control unit 22 Read side clock signal reproducing unit 23 Horizontal synchronizing signal generating unit 24 Vertical synchronizing signal reproducing unit 25 Read side clock signal 26 Output video signal 27 Output synchronizing signal 28 Horizontal fixed scan and vertical variable scan display 31 Input video signal 32 input Sync signal 33 Scan converter 34 A / D converter 35 Memory 36 Integer multiplication processing unit 37 D / A converter 38 Write side clock signal reproduction unit 39 Write side clock signal 40 Integer multiplication control unit 41 Vertical synchronization selection unit 42 Read side clock Signal playback unit 3 Horizontal sync signal generator 44 Vertical sync signal generator 45 Read side clock signal 46 Output video signal 47 Output sync signal 48 Horizontal fixed scan and vertical switching scan display 51 Input video signal 52 Input sync signal 53 Scan converter 54 A / D Converter 55 Interpolation calculation (reduction) processing unit 56 Memory 57 Interpolation calculation (enlargement) processing unit 58 D / A converter 59 Write side clock signal reproduction unit 60 Write side clock signal 61 Interpolation calculation control unit 62 Read side clock signal Playback unit 63 Horizontal synchronization signal generation unit 64 Vertical synchronization signal generation unit 65 Read-side clock signal 66 Output video signal 67 Output synchronization signal 68 Fixed scan display

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 5/68 Z 9068-5C

Claims (2)

[Claims] 1. A write-side clock signal reproducing section for reproducing a write-side clock signal from an input synchronizing signal, an A / D converter for sampling an input video signal, and a memory for storing the output of the A / D converter. , An integer multiple control unit that controls how much the input synchronization signal is multiplied by an integer in the vertical direction, a horizontal synchronization signal generation unit that generates a fixed frequency output horizontal synchronization signal, and a read side clock signal from the output horizontal synchronization signal A clock signal reproduction unit on the reading side for reproducing the signal, a vertical synchronization control unit for controlling the frequency of the output vertical synchronization signal, a vertical synchronization signal reproduction unit for reproducing the vertical synchronization signal under the control of the vertical synchronization control unit, and the integer An integer multiple processing unit for multiplying the output of the memory by an integer in the vertical direction under the control of the multiple control unit,
A scan converter having a D / A converter for D / A converting the output of the integer multiple processing unit, an output video signal of the D / A converter that is the output of the scan converter, the horizontal synchronization signal generating unit, and A display device comprising a horizontal fixed scan display and a vertical variable scan display which receive an output synchronizing signal of a vertical synchronizing signal reproducing section as an input. 2. A write-side clock signal reproducing section for reproducing a write-side clock signal from an input synchronizing signal, an A / D converter for sampling an input video signal, and a memory for storing the output of the A / D converter. , An integer multiple control unit that controls how much the input synchronization signal is multiplied by an integer in the vertical direction, a horizontal synchronization signal generation unit that generates a fixed frequency output horizontal synchronization signal, and a read side clock signal from the output horizontal synchronization signal A clock signal reproducing unit on the reading side for reproducing the signal, a vertical synchronization selecting unit for selecting the frequency of the output vertical synchronizing signal, a vertical synchronizing signal generating unit for generating a vertical synchronizing signal under the control of the vertical synchronizing control unit, and the integer. An integer multiple processing unit for multiplying the output of the memory by an integer in the vertical direction under the control of the multiple control unit,
A scan converter having a D / A converter for D / A converting the output of the integer multiple processing unit, an output video signal of the D / A converter that is the output of the scan converter, the horizontal synchronization signal generating unit, and A display device comprising a horizontal fixed scan display and a vertical switching scan display which receive an output synchronization signal of a vertical synchronization signal reproducing section as an input.