KR100815332B1 - White Balance Controlling Method of Display System having Individual Red, Green and Blue Laser Diode Light Source - Google Patents

Abstract

The present invention relates to a white balance adjustment method of a display system having individual R, G, B laser diode light sources that can control white light sources and adjust white balance without sacrificing gradation.

White balance, diffractive light modulator, color temperature, light intensity

Description

White Balance Controlling Method of Display System having Individual Red, Green and Blue Laser Diode Light Source}

1 is a structural diagram of a reflective changeable grating light modulator according to the prior art;

Figure 2 is a cross-sectional view of the recessed thin film piezoelectric optical modulator according to the prior art.

3 is a graph showing the loss of display gradation caused by the prior art.

Figure 4 is a block diagram of a display system using a diffractive optical modulator according to an embodiment of the present invention.

5 is a block diagram illustrating a projection control unit and a memory of FIG. 3.

6 is a flowchart illustrating a method of adjusting white balance of a display system having individual R, G, and B laser diode light sources according to an exemplary embodiment of the present invention.

7 is a graph measuring the amount of current outputting the maximum amount of light.

<Description of the symbols for the main parts of the drawings>

202: image signal input unit 204: image correction unit

206: upper electrode voltage range adjusting unit 208: lower electrode voltage adjusting unit

210: image data / synchronous signal output unit 212: light source output control unit

214: Scanner output control

The present invention relates to a display system having an individual R, G, B laser diode light source, and more particularly, to an individual R, G, B laser diode light source capable of controlling the individual light sources to adjust the white balance without sacrificing gradation. The present invention relates to a method for adjusting the white balance of a display system.

Recently, micromachining technology for manufacturing micro optical components such as micro mirrors, micro lenses and switches, micro inertial sensors, micro biochips and micro wireless communication devices using semiconductor device manufacturing processes has been developed.

Here, the micro mirror is operated in various ways according to the dynamic and static movement of the vertical direction, the rotation direction and the sliding direction. Up and down motion is applied to phase compensator and diffractometer, and tilting motion is applied to scanner, switch, optical signal splitter, optical signal attenuator and light source array, and sliding motion is light shield or switch. , Optical signal splitter, etc.

An example of such a micro mirror is a reflective deformable grating light modulator 10 as shown in FIG. 1. Such a light modulator 10 is disclosed in US Pat. No. 5,311,160 to Bloom et al. The light modulator 10 includes a plurality of regularly spaced deformable reflective ribbons 18 having reflective surface portions 22 and suspended above the substrate 16. An insulating layer 11 is deposited on the silicon substrate 16. Next, deposition of the sacrificial silicon dioxide film 12 and the silicon nitride film 14 is followed.

The silicon nitride film 14 is patterned from the ribbon 18 and a portion of the silicon dioxide film 12 is etched so that the ribbon 18 is held on the oxide spacer layer by the nitride frame 20.

In order to modulate light having a single wavelength λ _0, the optical modulator 10 is designed with the thickness of the thickness of the sacrificial silicon dioxide film 12 of the ribbon 18 so that the λ _0/4.

The grating amplitude of this optical modulator 10, defined by the vertical distance d between the reflective surface 22 on the ribbon 18 and the reflective surface 22 of the substrate 16, acts as a ribbon 18 (which serves as the first electrode). It is controlled by applying a voltage between the reflective surface 22 of the ribbon 18 and the substrate 16 (conductive film 24 under the substrate 16 serving as the second electrode).

2 is a cross-sectional view of a recessed thin film piezoelectric optical modulator according to the related art.

Referring to FIG. 2, the recessed thin film piezoelectric optical modulator according to the related art includes a silicon substrate 31 and an element 40.

Here, the element 40 has a constant width and a plurality of constant alignment to form a recessed thin film piezoelectric optical modulator. In addition, the elements 40 have different widths and alternately arranged to form a recessed thin film piezoelectric optical modulator. Finally, the elements 40 may be spaced apart from each other at a predetermined distance (almost the same distance as the width of the element 40), in which case the micromirror layer formed on the entire upper surface of the silicon substrate 31 is The incident light is reflected and diffracted.

The silicon substrate 31 has a depression for providing an air space to the element 40, an insulating layer 32 is deposited on the upper surface, and end portions of the element 40 are attached to both sides of the depression. .

The element 40 has a rod shape, and the bottom surfaces of both ends are attached to both side regions outside the recessed portion of the silicon substrate 31 so that the center portion is spaced apart from the recessed portion of the silicon substrate 31. The portion located in the depression of 31 includes a lower support 41 which is movable up and down.

In addition, the element 40 is stacked on the left end of the lower support 41, and is laminated on the lower electrode layer 42a and the lower electrode layer 42a for providing a piezoelectric voltage, and contracts and expands when a voltage is applied to both surfaces. And an upper electrode layer 44a laminated on the piezoelectric material layer 43a and the piezoelectric material layer 43a for generating the vertical driving force, and providing a piezoelectric voltage to the piezoelectric material layer 43a.

In addition, the element 40 is stacked on the right end of the lower support 41, and is laminated on the lower electrode layer 42b and the lower electrode layer 42b for providing a piezoelectric voltage, and contracts and expands when a voltage is applied to both surfaces. And an upper electrode layer 44b laminated on the piezoelectric material layer 43b and the piezoelectric material layer 43b for generating a vertical driving force, and providing a piezoelectric voltage to the piezoelectric material layer 43b.

On the other hand, the above-described optical modulator can be applied to various parts, the conventional display using the above-described optical modulator has a problem that the display gradation is lost when white balancing (white balancing) adjustment.

In other words, in the conventional art, correction data for white balance adjustment is present in each address in the form of a memory, and thus red (R) and green (R) output from the analog / digital converter after converting the input image data from the analog / digital converter to digital Since the data for white balance adjustment is determined according to the (G) and blue (B) signals, the data is included in the red (R), green (G), and blue (B) signals, and outputted.

That is, the maximum output luminance is generated when the maximum gray level (255 in 8 bit) is input, but the maximum output ratio of each of the red (R), green (G), and blue (B) light sources is determined by the actual white balance. Since the output luminance actually used by the output ratio uses only the reference output luminance LOW section from the reference output luminance HIGH as shown in FIG. 3, the range of usable gradation is reduced. That is, the loss of the display gradation degree occurs.

The present invention has been made to solve the above problems, the method of adjusting the white balance of the display system having a separate R, G, B laser diode light source that can adjust the white balance without sacrificing the gradation by controlling the individual light source The purpose is to provide.

In order to achieve the above object, a white balance adjustment method of a display system having individual R, G, and B laser diode light sources according to an exemplary embodiment of the present invention includes (a) outputting maximum grayscale data of each of red, green, and blue light sources. A first step of measuring a current outputting a maximum amount of light of each light source at a time; (b) a second step of setting a light source for outputting a minimum light quantity among the red, green, and blue light sources as a minimum light quantity output light source; (c) a third step of setting the light quantity ratio of said red, green and blue light sources according to an arbitrary target color temperature; And (d) determining the amount of applied current according to the amount of light output for each light source on the basis of the light quantity ratio of the light source and the minimum light quantity output light source.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram of a mobile display system using a diffractive optical modulator according to an embodiment of the present invention.

Referring to FIG. 4, a mobile display system using a diffractive optical modulator according to an embodiment of the present invention includes a wireless communication unit 110, a key input unit 112, a first memory 114, a baseband processor 116, and an image. The sensor module processor 118, the display unit 120, the optical modulator projector 130, and the second memory 170 are included.

The wireless communication unit 110 performs wireless communication with an external system, the key input unit 112 inputs information from the outside, and the first memory 114 stores data such as image data.

The baseband processor 116 allows the image image to be displayed on the display unit 120 or controls the projection control unit 140 of the optical modulator projector 130, which is a display system using a diffractive optical modulator, to display the image image on the screen 160. ) To be projected.

The image sensor module processor 118 processes the image input from the provided camera or the like and transmits the processed image image data to the baseband processor 116.

The display unit 120 displays the video image data supplied from the baseband processor 116 on the screen.

 The wireless communication unit 110, the key input unit 112, the first memory 114, the baseband processor 116, the image sensor module processor 118, and the display unit 120 may be referred to as a terminal control system.

The optical modulator projector 130 enlarges the generated image after generating an image image according to the image image data received from the baseband processor 116 by using the diffractive optical modulator under the control of the baseband processor 116. To project onto the screen 160. The light modulator projector 130 includes a projection control unit 140 and a light modulation optical system 150.

The projection control unit 140 outputs the optical modulation optical system 150 such that the optical modulation optical system 150 generates an image according to the image image data input from the baseband processor 116 according to a control signal received from the baseband processor 116. To control. As illustrated in FIG. 5, the projection controller 140 may include an image input unit 202, an image correction and control unit 204, an upper electrode voltage range adjusting unit 206, a lower electrode voltage adjusting unit 208, and image data / synchronization. The signal output unit 210, the light source output control unit 212, and the scanner output control unit 214 are configured. Detailed description thereof will be described later.

The light modulation optical system 150 generates an image image according to a control signal input from the projection control unit 140 and enlarges the generated image image and projects the generated image image on the screen 160. The light modulation optical system 150 includes a light source system 151, an illumination optical unit 152, a diffractive light modulator 153, a schlieren optical unit 154, and a projection and scanning optical unit 155.

The light source system 151 generates and emits red (R), green (G), and blue (B) light sources according to the light source switching control signal supplied from the projection control unit 140, and the illumination optical unit 152 emits light. The light emitted from 151 is incident on the diffractive light modulator 153.

The diffractive light modulator 153 diffracts the light incident from the illumination optical unit 152 according to the image data signal, the reference voltage, the lower electrode voltage, the vertical synchronization signal, and the horizontal synchronization signal supplied from the projection control unit 140 ( That is, the illumination optical unit 152 diffracts the incident light to form diffracted light having a plurality of diffraction orders. In this case, any one or multiple orders of diffraction light among the plurality of diffraction orders are desired. Create an image) Create a video image.

The schlieren optical unit 154 passes the diffracted light of the desired order in the plurality of orders of the diffracted light generated by the diffractive light modulator 153.

The projection and scanning optics 155 project an image of the diffraction light that has passed through the schlieren optics 154 onto the screen 160.

The second memory 170 stores control index values for each of the red, green, and blue light sources. Here, the control index value is set by the off-line test by the following method.

First, the wavelength of each of the red (R), green (G), and blue (B) light sources and an arbitrary target color temperature (for example, 10000K) are set. At this time, the light amount ratio (eg, R: G: B = α: β: δ) of each of the red (R), green (G), and blue (B) light sources is determined according to the set color temperature.

In addition, while increasing the amount of current supplied to each of the red (R), green (G), and blue (B) light sources to output the maximum gray scale data, the amount of current outputting the maximum light amount is measured and then red (R), green (G). ) And a light source that outputs the minimum amount of light among the blue (B) light sources. For example, when R: G: B: = a: b: c (a> b> c, a, b, c are light quantity output amounts), the blue (B) light source is determined as a light source that outputs the minimum amount of light.

Accordingly, the light quantity output amount a of the red (R) light source is set to c * α / δ based on the light quantity output amount c of the blue (B) light source, and the light quantity output amount b of the green (G) light source is c * β / δ. At this time, the light output amounts (a, b, c) of the set red (R), green (G), and blue (B) light sources are set to control index (R_index_max, G_index_max, B_index_max) values and are stored in the second memory 170. Stored.

The second memory 170 may be integrated with the first memory 114 constituting the terminal control system.

FIG. 5 is a block diagram illustrating the projection control unit shown in FIG. 4.

Referring to FIG. 5, the projection control unit 140 includes an image signal input unit 202, an image correction unit 204, an upper electrode voltage range adjusting unit 206, a lower electrode voltage adjusting unit 208, and an image data / synchronous signal output unit. 210, a light source output controller 212 and a scanner output controller 214, and perform an interface function with the terminal control system and the second memory 170.

The image signal input unit 202 receives the image data signal RGB, the vertical sync signal Vsync, and the horizontal sync signal Hsync from the baseband processor 116, and receives the input image data signal RGB and the vertical sync signal ( Vsync) and horizontal sync signal (Hsync).

The image correcting unit 204 converts the image data signals raster supplied from the image input unit 202, that is, the horizontally aligned image data signals, into a vertical image data signal by performing data transpose, The vertical synchronization signal Vsync and the horizontal synchronization signal Hsync supplied from the input unit 202 are buffered.

In the case of the optical modulation optical system 150 using the diffractive optical modulator 153, the image correction unit 204 scans and displays a horizontal direction in contrast to a plurality of pixels arranged vertically. Pose.

In addition, the image corrector 204 sets N gamma reference voltages of red (R), green (G), and blue (B) light sources, respectively (N is determined by the gradation degree). Separate each of the (G) and blue (B) light sources, and convert each pixel according to the correction data for each pixel by the number of pixels (the number of vertical resolutions, i.e., the number of mirrors) * n (n depends on the correction method). Correct the paused image data signal.

The upper electrode voltage range adjusting unit 206 adjusts the range of the voltage to be supplied to the upper electrode of the optical modulator according to the image data signal input from the image correcting unit 204 and supplies it to the panel driver for driving the optical modulator panel. At this time, the optical modulator panel and the panel driver are the components constituting the diffractive optical modulator 153.

The lower electrode voltage adjusting unit 208 adjusts the voltage to be supplied to the lower electrode of the optical modulator according to the image data signal input from the image correcting unit 204 and supplies it to the optical modulator panel.

The image data / synchronization signal output unit 210 supplies the image data signal, the vertical synchronization signal, and the horizontal synchronization signal input from the image correction unit 204 to the panel driver, the light source output control unit 212, and the scanner output control unit 214. do.

The light source output control unit 212 controls the control indexes R_index_max, G_index_max, and the like according to the light output amounts a, b, and c of the red (R), green (G), and blue (B) light sources stored in the second memory 170. B_index_max) is supplied to determine the applied current to be supplied to each of the red (R), green (G) and blue (B) light sources, and the vertical and horizontal synchronizing signals supplied from the image data / synchronization signal output unit 210. It supplies to the light source driver which drives a light source accordingly. At this time, the light source and the light source driver are components constituting the light source system 151.

The scanner output control unit 214 supplies the image data signal supplied from the image data / synchronization signal output unit 210 to a scanner driver that drives the scanning device according to the vertical synchronization signal and the horizontal synchronization signal. In this case, the scanning device and the scanner driver are components that constitute the projection and scanning optics 155.

FIG. 6 is a flowchart illustrating a method of adjusting white balance of a display system having individual R, G, and B laser diode light sources according to an exemplary embodiment of the present invention, and FIG. 7 is a graph measuring the amount of current outputting the maximum amount of light.

6 and 7, to output (S302) the maximum gray scale data (255 for 8-bit and 1024 for 10-bit) of each light source of red (R), green (G), and blue (B). As illustrated in FIG. 7, the amount of current outputting the maximum amount of light is measured while increasing the amount of current supplied to each of the red (R), green (G), and blue (B) light sources (S304).

Thereafter, the light source outputting the minimum amount of light among the red (R), green (G), and blue (B) light sources is determined using the measured value (S306). For example, when the red (R) light source outputs 1 W, the green (G) light source is 2 W, and the blue (B) light source outputs 0.5 W, the blue (B) light source is set as the minimum light output light source.

Further, the wavelength of each of the red (R), green (G) and blue (B) light sources and an arbitrary target color temperature (for example, 10000K) are set (S308), and red (R), The light amount ratio (for example, R: G: B = α: β: δ) of each of the green (G) and blue (B) light sources is determined (S310).

Thereafter, the amount of light output of each of the red (R), green (G), and blue (B) light sources is determined according to the light quantity ratio of the red (R), green (G), and blue (B) light sources and the set minimum light output light source. (S312).

At this time, the light quantity output amounts (a, b, c) of the red (R), green (G), and blue (B) light sources are based on the light quantity output amount (c) of the blue (B) light source. (a) is set to c * α / δ, and the light quantity output amount b of the green (G) light source is set to c * β / δ.

When the light output of each of the red (R), green (G), and blue (B) light sources is determined, red (R), green, depending on the light output of each of the red (R), green (G), and blue (B) light sources The applied current to be supplied to each of the (G) and blue (B) light sources is determined (S314).

Thereafter, the determined applied current is supplied to each of the red (R), green (G), and blue (B) light sources.

The white balance adjustment method of this method is performed before shipment of a display system having individual R, G, and B laser diode light sources.

As described above, the white balance adjusting method of the display system including the individual R, G, and B laser diode light sources according to the exemplary embodiment of the present invention uses a maximum light output current amount for each light source to output the maximum gray scale data. After determining the light quantity ratio of each light source according to the determined minimum light quantity output light source and the arbitrarily set target color temperature, the light quantity output amount for each light source is determined, and the current according to the determined light quantity output quantity is supplied to each light source so that white balance is not lost. Can be adjusted.

As described above, the present invention determines the minimum light amount output light source using the maximum light amount output current amount for each light source for outputting the maximum gray scale data, and then determines the minimum light amount output light source and the light quantity ratio of each light source according to an arbitrarily set target color temperature. By determining the light quantity output amount for each light source and supplying a current according to the determined light quantity output amount to each light source, the white balance can be adjusted without losing display gray scale.

Claims (4)

(a) measuring a current outputting a maximum amount of light of each light source when outputting the maximum grayscale data of each of the red, green, and blue light sources; (b) setting a light source that outputs a minimum light quantity among the red, green, and blue light sources as a minimum light output light source; (c) setting a light quantity ratio of said red, green and blue light sources according to an arbitrary target color temperature; And and (d) determining the applied current amount according to the light quantity output amount of each light source based on the light quantity ratio of the light source and the minimum light quantity output light source. How to adjust the white balance of your system. The method of claim 1, (e) after the output amount for each light source is determined, determining the current to be applied to each light source, and then supplying the determined current to each light source, the white of the display system having individual R, G, B laser diode light sources. How to adjust the balance. The method according to claim 1 or 2, The maximum gray level in the step (a) is 255 when the input image data is 8-bit data, characterized in that the white balance adjustment method of the display system having a separate R, G, B laser diode light source. The method according to claim 1 or 2, The maximum gray level in the step (a) is 1024 when the input image data is 10-bit data, characterized in that the white balance adjustment method of the display system having a separate R, G, B laser diode light source.

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