JPH1063213A - Screen saver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the burning of a screen without using software for screen saver, by displaying characters by changing the colors of snow noises corresponding to character parts in accordance with the on-off instruction of the screen saver. SOLUTION: A video signal processing section 11 forms RGB signals by subjecting the video signals(snow noises) from a television tuner section 2 to Y-C sepn. A switching section 14 turns the corresponding digital RGB signals read out of a field memory section 13 on and off for every signal. A noise detecting section 15 detects the snow noise from the digital RGB signals from an AD conversion section 12. A microcomputer section 20 is inputted with the on instruction of the screen saver and, therefore, supplies the character data to be displayed, the color selection signals of the character and the required data to a character forming section 17. The colors of the snow noises corresponding to the character parts are changed to assigned colors, for example, red, etc., in accordance with the on-off instruction of the screen saver, by which the character composed of the red noises, etc., are displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a screen saver for a personal computer compatible television.

[0002]

2. Description of the Related Art As televisions for personal computers, for example, P
2. Description of the Related Art Flat-panel televisions using a DP (plasma display panel) or the like as a display device are entering a period of widespread use. FIG. 5 is a system diagram of a personal computer compatible television. In TV mode, PDP
The panel unit 1 receives a video signal from the television tuner unit 2 and displays a television broadcast. In the personal computer mode, a personal computer signal is input from the personal computer unit 3 to display a personal computer screen.

[0003] In general, most still images are displayed on a personal computer, and the same image is often displayed continuously for a long time. Therefore, the display element is partially deteriorated, and a so-called burn-in phenomenon occurs. Therefore, a screen saver is activated to prevent the screen burn-in, and the position of the high-luminance portion of the screen of the display device is changed in a short time. For this reason, conventionally, screen saver software has been introduced into a personal computer to generate a moving image, and, for example, a screen in which a linear pattern, a petal pattern, a star pattern, or the like constantly moves is displayed.

In the case of a flat panel television using a PDP or the like in the personal computer mode, it is necessary to use a screen saver to prevent screen burn-in.

However, in the conventional method of preventing screen burn-in using a screen saver, there is a problem of an increase in cost due to the purchase of screen saver software.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a screen saver which prevents screen burn-in without using screen saver software.

[0007]

In order to achieve the above object, a television tuner section for receiving a television broadcast and outputting a demodulated video signal, and a video signal processing section for converting the video signal into primary color RGB signals. , The RGB signals of the primary colors
An A / D converter for digitizing each B, a field memory for storing digital RGB signals for each field, a switching unit for on-off controlling the digital RGB signals read from the field memory for each RGB, A noise detection unit that detects snow noise from an RGB signal; a character generation unit that generates a character signal; a control signal generation unit that generates a control signal of the switching unit from a detection result of the noise detection unit and a character signal; A determining unit that determines whether a channel selected from the video signal is a no signal,
A microcomputer section for inputting a screen saver on-off instruction to select the TV tuner section and to supply character data to a character generation section. Based on the screen saver on-off instruction, a snow part corresponding to a character portion is provided. A screen saver that changes the color of the noise to display text.

The noise detector is composed of three comparators for comparing the level of each of the RGB signals, and an AND element for calculating the logical product of the outputs of the comparators.

[0009] Three inverters connecting the control signal generator for each of the RGB character signals output from the character generator, a first AND element for each of the three inverters having a first input for each of the three inverters. And three second AND elements connected to the first input of each of the first AND elements, and the output of the noise detection unit is applied to the second input of the first AND element. And an RGB selection signal corresponding to the first input of the three second AND elements is connected, and one of the RGB character signals is connected to the second input.

The switching section comprises three on-off switches provided for each of the RGB signals, and the on-off switches are controlled by the control signal generated by the control signal generation section.

[0011] The character output by the character generation section may be a scrolling character, and the scrolling character may be displayed by changing the color of snow noise corresponding to the scrolling character.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above configuration, FIG.
For example, a case where characters are composed of red noise will be described with reference to FIG. As shown in FIG. 3B, an inverted signal of the RGB character signal is generated. An inverted signal of the R character signal is added to the selected snow noise gated by the character signal by an OR gate to generate an R control signal. On the other hand, as for the inverted signals of the G character signal and the B character signal, since the G and B character signals are not selected, the output of the AND gate is 0, so that the G control signal and the B control signal are generated as they are. Each of the RGB signals (snow noise) of the switching unit is controlled by using the R control signal, the G, and the B control signals. Therefore, as shown in FIG. Can display characters. In addition, green letters, blue letters or RG
When two colors are selected from the three colors B and combined, the display can be performed using the control signal generated in the same manner as the red color.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a screen saver according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment circuit for generating a screen saver according to the present invention. Reference numeral 2 denotes a television tuner unit that receives a television broadcast and outputs a demodulated video signal. Reference numeral 11 denotes a video signal processing unit that converts the video signal into a primary color RGB signal. Reference numeral 12 denotes an AD conversion unit that digitizes the primary color RGB signals for each signal. Reference numeral 13 denotes a field memory unit that stores digital RGB signals for each field. 14
Is a switching unit for performing on-off control of the digital RGB signals read from the field memory unit 13 for each signal. Reference numeral 15 denotes a noise detection unit that detects snow noise from the digital RGB signals. Reference numeral 17 denotes a character generation unit that generates a character signal. 16 is the noise detection unit 15
Is a control signal generation unit that generates a control signal for controlling the switching unit 14 from the detection result of the above and the character signal. 19
Is a determination unit that determines whether a channel selected from the video signal is a no signal. Reference numeral 20 denotes a microcomputer unit that inputs a screen saver on-off instruction, selects the TV tuner unit 2, and supplies character data to the character generation unit 17.

A schematic operation of an embodiment of a circuit for generating a screen saver according to the present invention will be described with reference to FIG. First, in the initial setting mode when the power is turned on, the microcomputer unit 20 selects the TV tuner unit 2 and, for example,
The determination unit 19, which sequentially selects from channel 1 to the last channel, determines whether or not the currently selected channel is a non-signal by detecting the presence or absence of a synchronization signal, for example. 20 stores this result in an internal RAM or the like as a non-signal channel.

Next, when a screen saver ON instruction is input in the personal computer mode, the microcomputer unit 20 selects one of the stored non-signal channels. The video signal processing section 11 separates the video signal (snow noise) from the TV tuner section 2 into YC signals to generate RGB signals. AD
The conversion unit 12 generates digital RGB signals, and the field memory unit 13 stores the digital RGB signals for each field. The switching unit 14 is provided in the field memory unit 1.
The on / off control of the corresponding digital RGB signals read out from 3 is performed for each signal. The noise detection unit 15 detects snow noise from the digital RGB signals from the AD conversion unit 12, and the control signal generation unit 16
From the character signal generated by the character generation unit 17, the switching unit 14
To generate a control signal for controlling. On the other hand, since the screen saver ON instruction is input to the microcomputer unit 20, the characters to be displayed in the character generation unit 17, for example, character data such as "screen saver", the character color selection signal and the character are fixed, scrolling, etc. Supply the required data. By changing the color of the snow noise corresponding to the character portion to a designated color, for example, red based on the on / off instruction of the screen saver, a character composed of red noise or the like is displayed.

The detailed operation of the screen saver according to the present invention will be described with reference to FIGS. FIG. 2 is a circuit block diagram showing a main circuit of an embodiment for generating a screen saver according to the present invention. FIG. 3 is a diagram (a) showing a display example of a screen saver for generating a screen saver according to the present invention, and a timing diagram (b) of generating a control signal. First, as shown in FIG. 2, the noise detection unit 15 includes a comparator 25 that compares the level with one of the RGB signals, for example, the R signal. Therefore, as shown in FIG. 3B, the output of this circuit is 1 only when the R signal level of the snow noise is equal to or higher than the reference level, and is 0 in other cases. In other words, snow noise is detected. The snow noise shown in FIG. 3B is shown in FIG.
2 shows a portion corresponding to the scanning line AA ′. Alternatively, the noise detection unit 15 may be configured with three comparators that perform level comparison for each of the RGB signals and an AND element that calculates a logical product of outputs of the comparators. In the case of a configuration using three comparators, although the number of comparators increases, malfunction due to color noise can be prevented.

Hereinafter, for example, a case where a character is composed of red noise will be described in detail. Control signal generator 16
Is, as shown in (b) of FIG.
3 inverters 2 connected for each of the RGB character signals output by
6 generates an inverted character signal, and converts the inverted character signal and the selected snow noise generated by the first AND element 23 into:
The control signal (R) is generated by performing an OR operation on the OR element 22. Similarly, the inverted character signal is ORed with the 0 signal generated by the first AND element 23 to generate a control signal (G) and a control signal (B).

The description will be continued. When characters are composed of red noise, the microcomputer unit 20 (FIG. 1) uses R, G, B
Since the logical values of the selection signal are supplied as “1”, “0”, and “0”, the output of the second AND element 24 is a logical product, and the “character signal”,
"0" and "0". Accordingly, the output of the first AND element 23 is obtained by performing a logical product operation on the output (snow noise) of the noise detection unit and the "character signal", "0", and "0", in that order as shown in FIG. As shown in FIG. 7, the “snow noise after selection” is “0”, “0”. FIG. 4 is a circuit block diagram showing a main part circuit of another embodiment for generating a screen saver according to the present invention. By using this example, it is possible to realize a screen saver in which a character is formed by snow noise and a black screen is formed in a portion other than the character portion. In this case, the control signals (R), (G), and (B) are converted into the character signals (R), (G), and (B) generated by the character generator 17.
May be used as is, or one character signal of (R), (G) and (B) may be used. The signal waveform is shown in FIG.
As shown in (b), only the portion corresponding to the character portion has a signal waveform of “1”. Further, the control signal (R)
By using only, it is possible to realize a screen saver in which red noise characters are displayed on a black screen. Other green, blue, etc. can be realized similarly.

The switching section 14 comprises three on-off switches (SW) 21 provided for each of the RGB signals.
The off switch 21 is controlled by a corresponding control signal generated by the control signal generator 16. Therefore, as shown in FIG. 3A, the digital RGB signal read out from the field memory unit 13 at a required timing so as to synchronize the corresponding snow noise with the control signal is converted into the digital RGB signal shown in FIG.
, Three control signals (R), (G),
In (B), on / off control is performed. For example, when characters are displayed with red noise, only the R signal of the digital RGB signals is output and the GB signal is controlled to be off.

It should be noted that the determination unit 19 can be similarly determined by accumulating the detection result of the noise detection unit by the microcomputer unit 20 and determining by software based on the accumulated value. Is unnecessary. When the character generation unit 17 outputs scroll characters in accordance with an instruction from the microcomputer unit 20, the color is given only to snow noise corresponding to the scroll character portion, and, for example, scroll characters such as green can be displayed. . In the above description, characters are composed of red noise. However, according to the present technology, green, blue, and the like can be similarly realized.

[0021]

As described above, the present invention provides a screen saver which prevents screen burn-in without using screen saver software. Therefore,
As a personal computer compatible television, for example, PDP (plasma d
In an isplay panel, etc., since the circuits from the TV tuner unit 2 to the field memory unit 13, the character generation unit 17, the microcomputer unit 20, and the like can use existing circuits, the above-described noise detection unit 15, control signal generation unit 16 and the switching unit 14 can be realized by a simple logic circuit. It is possible to implement this logic circuit as an IC at a low cost, and it is not necessary to purchase screen saver software as in the related art. This technology has the advantage of preventing an increase in operating costs.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment circuit for generating a screen saver according to the present invention.

FIG. 2 is a block diagram showing a main circuit of an embodiment for generating a screen saver according to the present invention.

FIG. 3 is a diagram (a) showing a display example of a screen saver for generating a screen saver according to the present invention, and a timing diagram (b) of generating a control signal.

FIG. 4 is a circuit block diagram showing a main part circuit of another embodiment for generating a screen saver according to the present invention.

FIG. 5 is a system diagram of a personal computer compatible television.

[Explanation of symbols]

 Reference Signs List 1 PDP panel section 2 TV tuner section 3 Personal computer section 11 Video signal processing section 12 A / D conversion section 13 Field memory section 14 Switching section 15 Noise detection section 16 Control signal generation section 17 Character generation section 19 Judgment section 20 Microcomputer section 21 On-off Switch (SW) 22 OR element 22 23 First AND element 24 Second AND element 25 Comparator 26 Inverter

Claims (9)

[Claims] A television tuner section for receiving a television broadcast and outputting a demodulated video signal;
A video signal processing unit for converting the image into a RGB signal;
An AD converter for digitizing a signal for each signal, a field memory for storing digital RGB signals for each field, and a digital R read from the field memory.
A switching unit that performs on-off control of a GB signal for each signal, a noise detection unit that detects snow noise from the digital RGB signal, a character generation unit that generates a character signal, a detection result of the noise detection unit, and a character signal A control signal generation unit for generating a control signal for the switching unit from the control unit, a determination unit for determining whether or not a channel selected from the video signal is a non-signal, and an ON / OFF instruction for a screen saver, The tuner section is selected, and the microcomputer section that supplies character data to the character generation section is configured to display characters by changing the color of snow noise corresponding to the character portion based on the screen saver on-off instruction. Screen saver. 2. The screen saver according to claim 1, wherein said noise detector comprises three comparators for comparing the level of each of the RGB signals, and an AND element for calculating a logical product of outputs of the respective comparators. 3. The screen saver according to claim 1, wherein said noise detection unit comprises a comparator for comparing the level of one of the RGB signals with one of the RGB signals. 4. Inverters connecting the control signal generator for each of RGB character signals output by the character generator,
Three OR elements each having the three inverters as a first input and connecting a first AND element for every second input, and three second ANDs each connecting to a first input for each of the first AND elements
An output of the noise detection section is connected to a second input of the first AND element, and an RGB selection signal corresponding to a first input of the three second AND elements is connected to the second input. 2. The screen saver according to claim 1, wherein one of the RGB character signals is connected to the signal. 5. The screen saver according to claim 4, wherein said inverter comprises three inverters connected to any one of RGB character signals. 6. The control unit according to claim 1, wherein said switching unit comprises three on-off switches provided for each of RGB signals, and said on-off switch is controlled by a control signal generated by said control signal generating unit. The described screen saver. 7. The apparatus according to claim 1, wherein said switching unit comprises three on-off switches provided for each of RGB signals, and said on-off switches are controlled by a character signal output from said character generation unit. Screen saver. 8. The screen saver according to claim 1, wherein said discriminating section accumulates the detection result of said noise detecting section and makes a discrimination based on the accumulated value. 9. The screen saver according to claim 1, wherein the character generation unit outputs scroll characters, and displays the scroll characters by changing the color of snow noise corresponding to the scroll character portions.