JPH10174012A - Character display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display characters of an image of a personal computer onto a home use television receiver in an easy-to-see way. SOLUTION: This character display device reads out character data or the like stored in an image memory 1 through a control section 3 by using a clock from a clock generating section 2, and inputs the data to a terminal (a) of a selector 6 and a delay section 4. The character data or the like delayed by the delay section 4 are given to a terminal (b) of the selector 6, the clock from the clock generating section is given to a terminal (a) of a selector 7 and a delay section 5, and the clock delayed at the delay section 5 by the same time at the delay section 4 is given to terminal (b) of the selector 7. A frame discrimination section 8 discriminates a frame given to the display device and provides an output of an H or an L level signal at an interval of one frame to select the terminal (a) (non-delay terminal) of the selectors 6, 7 via a selector control section 9, or the terminal (b) (delayed terminal). Data from the selector 6 are given to a D/A converter section 10, in which the data are converted into an analog signal by using the clock from the selector 7, and encoder 11 converts the signal into a television signal and the signal is displayed on a screen of the television receiver or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character display device, and relates to a personal computer (hereinafter abbreviated as a personal computer).
The present invention relates to a device for displaying characters and the like of an image on a screen of a television (TV) receiver in a legible manner.

[0002]

2. Description of the Related Art Many monitors of personal computers have small screens because large screens are expensive and are not suitable for use by a large number of people at once. In addition, it is wasteful to provide a personal computer monitor when the frequency of use of the personal computer is relatively low, and in order to solve these problems, a personal computer image is displayed on a home TV receiver. There is. In this case, the video signal of the personal computer is subjected to flicker prevention processing so that flicker does not occur on the screen of the TV receiver. In the flicker prevention process, for example, 1/2 of the data of the first line of the odd field and 1/2 of the data of the first line of the even field are added to form the first line of the new odd field, and the first line of the new odd field is added. One half of the data of one line and one half of the data of the second line of the odd field are added to obtain the first line of the new even field. Thereafter, the same processing is performed to obtain new odd and even fields. Generate and prevent flicker from being seen by human eyes. The above is processing in the vertical direction. In the horizontal direction, for example, when the number of pixels in one line is 640, the width of one dot is about 75 nS (nanosecond).
Thus, there is a problem that the vertical line of the character is thin and the character is difficult to see on a home TV receiver having a coarse pixel pitch as compared with a monitor of a personal computer.

[0003]

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to increase the width of a vertical line when displaying characters of a personal computer image on a home TV receiver so that the characters can be easily viewed. .

[0004]

According to the present invention, an image memory for storing data such as characters is provided.
A first delay unit for delaying data such as characters read from the image memory for a required time, a first selector for switching data such as characters from the image memory and data from the first delay unit, Generating section for generating a clock for the same, a second delay section for delaying the clock from the clock generating section by the same time as the first delay section, and switching between the clock from the clock generating section and the clock from the second delay section. A second selector, a frame discriminator for discriminating a frame of the display device, and a first selector which is connected to the image memory side or the first memory based on a signal from the frame discriminator.
A selector control unit for switching the second selector in conjunction with the clock generation unit or the second delay unit on the delay unit side; and a first control unit based on a clock from the second selector.
A D / A converter for converting character data or the like from the selector into an analog signal, and an encoder for converting a signal from the D / A converter into a television signal, so as to display based on the signal from the encoder. A character display device is provided.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a character display device according to the present invention,
Data such as characters are stored in the image memory, data read from the image memory is delayed by a first delay unit for a required time, and data such as characters from the image memory and data from the first delay unit are switched by a first selector. , A clock for data processing of characters and the like is generated by a clock generation unit, the clock from the clock generation unit is delayed by the second delay unit by the same time as the first delay unit, and the clock from the clock generation unit and the second delay The clock from the unit is switched by the second selector, the frame of the display device is determined by the frame determination unit, and the first selector is switched to the image memory side or the first delay unit side via the selector control unit based on the signal from the frame determination unit. , The second selector is switched in conjunction with the clock generation unit or the second delay unit, and the D / A conversion unit uses the first selector based on the clock from the second selector. Rino character data or the like into an analog signal, converts the signal from the D / A converter into the television signal at the encoder, and displayed on the screen.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a character display device according to the present invention. FIG. 1 is a block diagram of a main part of an embodiment of a character display device according to the present invention. In FIG. 1, reference numeral 1 denotes an image memory for storing data such as characters.
Reference numeral 2 denotes a clock generation unit that generates a clock for data processing of characters and the like. Reference numeral 3 denotes a control unit that reads character data from the image memory 1 using a clock from the clock generation unit 2 and the like. Reference numerals 4 and 5 denote delay units. The delay unit 4 delays the data read from the image memory 1 for a required time, and the delay unit 5 delays the clock from the clock generation unit 2 by the same time as the delay unit 4. Reference numerals 6 and 7 denote selectors. The selector 6 switches data from the image memory 1 and the data from the delay unit 4, and the selector 7 switches a clock from the clock generation unit 2 and a clock from the delay unit 5. Reference numeral 8 denotes a frame discriminating unit which outputs an H signal or an L signal every other frame in accordance with frame switching of the display device. Reference numeral 9 denotes a selector control unit, which controls the selectors 6 and 7 based on a signal from the frame determination unit 8 in the image memory 1.
Switching to the (a) side and the clock generation unit 2 (a) side, or to the delay unit 4 (b) side and the delay unit 5 (b) side. Reference numeral 10 denotes a D / A converter, which converts character data and the like from the selector 6 into analog signals based on the clock from the selector 7. An encoder 11 converts a signal from the D / A converter 10 into a television signal and displays it on a screen.

Next, the operation of the character display device according to the present invention will be described. R such as characters stored in the image memory 1
The data of (red), G (green) and B (blue) are read out via the control unit 3 using the clock from the clock generation unit 2, input to the terminal a of the selector 6 and the delay unit 4, Is applied to the terminal b of the selector 6, and the clock from the clock generator 2 is input to the terminal a of the selector 7 and the delay unit 5, and is delayed by the delay unit 5 by the same time as the delay unit 4. The clock generated is the terminal b of the selector 7.
Is applied to As shown in FIG. 2, for example, the delay time of the delay units 4 and 5 is set to about 10 nS when the horizontal width (dot clock cycle) of the dots of the display data is 75 nS. Then, the frame switching of the display device is determined by the frame determining unit 8, an H signal or an L signal is output every other frame, and the selectors 6 and 7 are transmitted through the selector control unit 9.
Switching to the terminal a side with the H signal and switching to the terminal b side with the L signal. The display data from the selector 6 is supplied to the D / A converter 10.
The display data is converted into an analog signal based on the clock from the selector 7, converted into a television signal by the encoder 11, and output.

As described above, the selectors 6 and 7 are switched from the terminal a to the terminal b every other frame.
In the example shown in FIG. 7, the horizontal width of the display data (dot) of each frame is both 75 nS, but there is a time difference of 10 nS between the first frame and the second frame in the display position of the data. Since two pieces of display data overlap and appear as if the width is 85 ns, when the characters on a personal computer are displayed on a home TV receiver, the width of the vertical lines of the characters is widened and the characters are easy to see.

In the above description, the display data is switched to be delayed / not delayed every other frame. However, the display data may be switched every other field. In this case, a field discriminating section is provided to discriminate the odd field and the even field of the display device. The selectors 6 and 7 are connected to the terminal a (no delay) via the selector control section 9 in the odd field, and the selector 6 in the even field.
And 7 are switched to the terminal b (delay) side.

If the delay time of the delay units 4 and 5 is in a range (less than 75 nS) smaller than the width of one dot of the display data,
Although it may be longer than 10 ns, the width of the vertical line visible to the eye becomes too wide, so that it is close to other dots and does not affect the intelligibility.

[0011]

As described above, according to the character display device of the present invention, the display data of the personal computer image is displayed with a required time delay every other frame (or one field), so that the human eye is displayed. The width of the dots is widened by the afterimage, and characters and the like of a personal computer image can be displayed on a home TV receiver in a legible manner.

[Brief description of the drawings]

FIG. 1 is a main part block diagram of an embodiment of a character display device according to the present invention.

FIG. 2 is a time chart for explaining the operation of the character display device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image memory 2 Clock generation part 3 Control part 4, 5 Delay part 6, 7 Selector 8 Frame discrimination part 9 Selector control part 10 D / A conversion part 11 Encoder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 5/44 H04N 5/44 A

Claims (6)

[Claims] 1. An image memory for storing data of characters and the like, a first delay unit for delaying the data of characters and the like read from the image memory for a required time, a data and a first delay unit of characters and the like from the image memory A first selector for switching data from a second data unit, a clock generation unit for generating a clock for data processing of characters and the like, a second delay unit for delaying the clock from the clock generation unit by the same time as the first delay unit, A second selector for switching between a clock from a clock generation unit and a clock from a second delay unit, a frame discrimination unit for discriminating a frame of the display device, and the first selector based on a signal from the frame discrimination unit. Alternatively, a selector control unit that switches the second selector in conjunction with the clock generation unit or the second delay unit in the first delay unit, and the second selector. A D / A conversion unit for converting character data and the like from the first selector into an analog signal based on a clock from the detector, and an encoder for converting a signal from the D / A conversion unit to a television signal. Character display device for displaying based on the signal of 2. The frame discriminating unit outputs an H signal or an L signal every other frame, and the first selector is clocked by the H signal via the selector control unit, and the second selector is clocked by the H signal. 2. The character display device according to claim 1, wherein the character selector is switched to a generator, and the L signal switches the first selector to the first delay unit and the second selector to the second delay unit. 3. A field discriminator for discriminating a field of the display device, wherein the first selector is moved to the image memory side in the first field through the selector controller based on a signal from the field discriminator, and 2. The character display device according to claim 1, wherein a selector is switched to a clock generation unit, and the first selector is switched to a first delay unit and a second selector is switched to a second delay unit in a second field. 4. The field discriminating section outputs an H signal in a first field and an L signal in a second field, and outputs the first selector to the image memory by the H signal via the selector control section. 4. The apparatus according to claim 3, wherein the second selector is switched to the clock generator side, and the first selector is switched to the first delay section and the second selector is switched to the second delay section by an L signal. Character display device. 5. The apparatus according to claim 1, wherein the first delay unit delays data such as characters from the image memory by a required time shorter than a cycle of the clock. Character display device. 6. A horizontal width of a dot of a character or the like appears wide due to an afterimage of an image based on data of a character or the like from the image memory and an afterimage of an image based on data of a character or the like from a first delay unit. 6. The character display device according to claim 1, 2, 3, 4, or 5.