KR20010060995A - Raster controlling circuit and method for monitor - Google Patents

Abstract

PURPOSE: A circuit for controlling raster of monitor and a method the same are provided to control luminance level constantly by regulating cut-off voltage after placing center of bar which controls luminance of primary color signal on center of screen. CONSTITUTION: A CDT(cathode-ray display tube)(220) injects an electronic beam corresponding to a signal from a video output unit(210) into screen to display an image. A cut-off control unit(230) outputs a cut-off voltage(Vcut) which regulates a cathode terminal voltage of the CDT(220). A supply voltage control unit(240) controls the cut-off voltage(Vcut) from the cut-off control unit(230) according to a pulse width modulation signal(PWM) from a micro computer selected by a user in case of setting up of a raster control mode.

Description

Raster control circuit and method of monitor {RASTER CONTROLLING CIRCUIT AND METHOD FOR MONITOR}

TECHNICAL FIELD The present invention relates to monitors and, more particularly, to raster adjustment circuits and methods.

1 is a block diagram of a raster adjustment circuit of a conventional monitor, as shown in FIG. 1, a CDT 120 for scanning an image of a primary color signal from a video output unit 110 on a screen and displaying an image; Cut-off voltage ( ) Is configured as a cut-off control unit 130 to control the cathode terminal voltage of the CD (120).

Referring to the operation of the prior art as follows.

In general, in order to display an image on the screen of the CD 120, the amount of the electron beam scanned on the screen is adjusted by adjusting the voltage of the grid terminal G1.

Accordingly, when the video output unit 110 transmits the primary color signals R, G, and B, which are amplified to a predetermined level, to the cathode terminal of the CD 120, the cathode terminal voltage is controlled by the cut-off control unit 130. The primary color signal is scanned on the screen of the CD 130 to display an image on the screen.

On the other hand, when adjusting the sharpness of the image, the user presses a specific key for setting the image sharpness change to display the change menu on the on-screen screen, and then adjusts the sharpness using the adjustment keys. Same as and described as follows.

First, the user sets the adjustment level of the sub-bright BRT to the maximum position using the change menu displayed on the on-screen screen while the screen voltage G2 is fixed.

Thereafter, when the user adjusts the brightness of the primary color signal B to a predetermined luminance level by using the change menu displayed on the on-screen screen, the cut-off control unit 130 cuts off the cut-off voltage ( ) By adjusting the cathode terminal voltage of the CD 120 to adjust the screen brightness of the CD 120 to a predetermined brightness level.

The user then adjusts the color coordinates for the primary color signals R, G using the change menu displayed on the on-screen.

Thereafter, when the adjustment of the color coordinates for the primary color signals R and G is completed, the user adjusts the luminance by adjusting the level of the sub-bright SUB-BRT using the change menu displayed on the on-screen screen. .

Therefore, according to the user's adjustment of the sub-bright (SUB-BRT), the cut-off control unit 130 adjusts the cathode terminal voltage of the CD 120 to scan the amount of the electron beam scanned on the screen of the CD 120. Adjust the brightness of the image displayed on the screen.

However, in the related art, when the screen voltage is fixed, the sub bright is set at the maximum position, and the primary color signal B is adjusted to adjust to a constant luminance. If the luminance level of the primary color signal B is biased to the minimum or maximum, the cut-off adjustment is not performed due to the CDT deviation. Therefore, the CDT needs to be replaced.

Therefore, in order to improve the conventional problem, the present invention places the center of the bar for adjusting the brightness of the primary color signal B at the center of the on-screen screen and then cuts off voltage ( ), The center of the bar for adjusting the brightness of the primary color signal B is adjusted to the constant luminance level. It is an object of the present invention to provide a raster adjustment circuit and a method of a monitor designed to solve the conventional problem of preventing a bias or shift to a maximum or minimum position, thereby preventing cut-off adjustment due to CDT deviation.

1 is a block diagram of a conventional raster adjustment circuit.

2 is a signal flow diagram in the conventional raster adjustment.

3 is a block diagram of a circuit showing an embodiment of the invention.

4 is a detailed circuit diagram of a raster correction unit in FIG. 3.

5 is a signal flow diagram for an embodiment of the invention.

Explanation of symbols on the main parts of the drawings

210: video output unit 220: CDT (CDT)

230: cut-off control unit 240: supply voltage control unit

Q1, Q2: Transistor C1: Capacitor

R1 to R4: resistance

In order to achieve the above object, the present invention scans an electron beam corresponding to a signal from a video output unit on a screen to display an image, and displays the cathode terminal voltage of the cd according to a cut-off voltage. A monitor provided with a cut-off control unit for adjusting, comprising: a microcomputer outputting a pulse width modulated signal (PWM) for limiting the cut-off voltage at the user's choice when setting the raster adjustment mode; And a supply voltage control unit for adjusting a cut-off voltage provided to the cut-off control unit according to a pulse width modulation signal PWM.

The supply voltage controller includes a second transistor for transmitting a cut-off voltage to the cut-off controller, a first transistor for turning off the second transistor while a pulse width modulation signal is high, and the pulse width modulation signal. It is characterized by consisting of a resistor and a capacitor for charging and applying to the first transistor.

According to the present invention, when the raster adjustment mode is set, displaying the on-screen change menu, adjusting the sub-brightness to the maximum position using the on-screen change menu, and adjusting the primary color signal B Matching the center of the bar on the on-screen change menu to the center of the on-screen screen, and generating a pulse width modulated signal corresponding thereto by using an adjustment key for adjusting to a constant brightness level; After adjusting to a certain brightness level, the color coordinates of the primary color signals (R, G) are adjusted in the on-screen change menu, and the brightness is adjusted by adjusting the sub-brightness in the on-screen change menu. It is done.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 3 is a block diagram of an apparatus according to an embodiment of the present invention. As shown therein, a CDT 220 for displaying an image by scanning an electron beam corresponding to a signal from the video output unit 210 to a screen is shown. And a cut-off voltage for adjusting the cathode terminal voltage of the CD 220 according to the cut-off voltage. Cut-off control unit 230 for outputting the control signal to the cut-off control unit 230 according to a pulse width modulation signal PWM from a microcomputer (not shown) by a user's selection when the raster adjustment mode is set. Provided cut-off voltage ( ) Is configured as a supply voltage control unit 240 that limits.

As shown in the circuit diagram of FIG. 4, the supply voltage controller 240 grounds the emitter of the transistor Q1 applied to the base through the pulse width modulation signal PWM sequentially through the resistors R1 and R2. The connection point of the resistors R1 and R2 is grounded through the capacitor C1 and the cut-off voltage ) Is applied and the base of the transistor Q2 connected between the collector and the base of the resistor R4 is connected to the collector of the transistor Q1 through the resistor R3.

Cut-off voltage from the emitter of transistor Q21 ) Is outputted.

Referring to the operation and effect of the embodiment of the present invention configured as described above are as follows.

Even in the present invention, the primary color signals R, G, and B, which are amplified by a predetermined level, from the video output unit 210 are transmitted to the CD 220 in order to display an image on the screen of the CDT 220. Cut-off control unit 130 when the cut-off voltage ( By controlling the cathode terminal voltage of the CD 220 as an input to maintain the sharpness of the image displayed on the screen at a predetermined level.

On the other hand, if you want to adjust the sharpness of the image, the user presses a specific key for setting the image sharpness change to display the change menu on the screen, and then using the adjustment key cut-off voltage provided to the cut-off control unit 230 ( ) To adjust the sharpness of the image, which is the same as the signal flow diagram of FIG.

First, the user displays the change menu on the on-screen screen while the screen voltage G2 is fixed, and then sets the adjustment level of the sub-bright BRT to the maximum position by using the adjustment keys.

Afterwards, the user moves the center of the bar for adjusting the brightness of the primary color signal B. In order to prevent bias toward the maximum or minimum position, the center of the bar for adjusting the brightness of the primary color signal B is adjusted to be the center of the on-screen screen.

Accordingly, when the user adjusts the center of the bar for adjusting the brightness of the primary color signal B to match the center on the on-screen screen, and then adjusts the luminance level using the adjustment keys, the microcomputer (not shown) The cut-off voltage supplied to the cut-off control unit 230 Outputs a pulse width modulation signal PWM for adjusting () to the supply voltage controller 240.

At this time, the supply voltage controller 240 turns on the transistor Q1 by the voltage charged to the capacitor C1 through the resistor R1 while the pulse width modulation signal PWM is high, so that the base potential of the transistor Q2 is turned on. Since the transistor Q2 is grounded, the cut-off voltage ( ) Is not transmitted to the cut-off control unit 230.

On the contrary, while the pulse width modulation signal PWM is low, the supply voltage controller 240 has no charging voltage in the capacitor C1, so that the transistor Q1 is turned off and thus the cut-off voltage ( Is applied to the base via resistor R4, and at the same time the cut-off voltage ( ) Is sent.

Accordingly, the cut-off voltage (from the supply voltage control unit 240) ), The cut-off controller 130 adjusts the cathode terminal voltage of the CD 120 so that the screen brightness of the CD 120 is at a predetermined luminance level.

The user then adjusts the color coordinates for the primary color signals R, G on the change menu displayed on the on-screen screen.

Subsequently, when the adjustment of the color coordinates for the primary color signals R and G is completed, the user adjusts the brightness by adjusting the level of the sub-bright SUB-BRT on the change menu displayed on the on-screen screen.

Therefore, according to the user's adjustment of the sub-bright (SUB-BRT), the cut-off control unit 130 adjusts the cathode terminal voltage of the CD 120 to scan the amount of the electron beam scanned on the screen of the CD 120. Adjust the brightness of the image displayed on the screen.

As described in detail above, the present invention places the center of the bar for adjusting the brightness of the primary color signal B at the center on the on-screen screen, and then cuts off using a pulse width modulation signal from a microcomputer. Voltage( ) To adjust to a constant luminance level.

Accordingly, the present invention has the effect of reducing the loss of the CDT by solving the problem that the cut-off adjustment is not made due to the CDT deviation in the prior art.

Claims (3)

In the raster adjustment mode, display the on-screen change menu to adjust the sub-brightness to the maximum position, adjust it to a constant luminance level using the primary color signal (B), and adjust the color coordinates using the primary color signals (R, G). In the monitor for adjusting the brightness by adjusting the sub-bright, CDT for scanning the electron beam corresponding to the primary color signal (R, G, B) at the video output unit on the screen to display an image, Cut-off voltage ( A cut-off control unit for adjusting the cathode terminal voltage of the CDT and an on-screen change menu when the raster adjustment mode is set, and then for adjusting the brightness of the primary color signal B according to the user's adjustment. The center of the bar is aligned with the center of the on-screen display and the cut-off voltage ( Control means for outputting a pulse width modulated signal PWM for limiting the < Desc / Clms Page number 5 > A raster adjustment circuit of the monitor, characterized by further comprising a control unit. 2. The apparatus of claim 1, wherein the supply voltage controller comprises: a second transistor for transmitting a cut-off voltage to the cut-off controller, a first transistor for turning off the second transistor while a pulse width modulation signal is high; And a charging circuit comprising a resistor and a capacitor for charging the pulse width modulated signal and applying it to the first transistor. Adjust the sub-brightness to the maximum position, adjust it to a constant brightness level using the primary color signal (B), adjust the color coordinates using the primary color signals (R, G), and then adjust the sub-brightness to adjust the brightness. A raster adjustment method comprising the steps of adjusting a center of a bar for adjusting brightness of the primary color signal B to coincide with a center on an on-screen screen, and adjusting to a constant luminance level using a pulse width modulation signal. Raster adjustment method of the monitor, characterized in that it further comprises the step of.