KR0182451B1 - Pixel calibration method for video projection system having actuated mirror array panel - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pixel correction method of a projection image display device, and employs an AMA panel 24 having an optical modulation element (AMA element 24a) corresponding to the number of pixels, and employs optical modulation of the optical modulation element 24a. In the projection image display apparatus which forms an image signal by applying a test voltage to the optical modulation element 24a by switching, the minimum and maximum tilt angles are measured, and the measured minimum and maximum tilt angles and input voltages are measured. The pixel correction data is created based on the linearity of and the optical correction element 24a is driven by adding the generated pixel correction data to the pixel driving signal, thereby eliminating the influence of the initial tilting angle of the AMA element, thereby performing accurate optical modulation. To make it possible.

Description

Pixel Correction Method of Projection Image Display Device

1 is a block diagram of a projection image display apparatus employing a pixel correction method in the present invention.

2 is a view for explaining an example of an example for detecting the initial tilting angle of the pixel driving element in the pixel correction method of the projection image display image according to the present invention.

3 is a graph for explaining a relationship between a tilting angle of a pixel driver and an input voltage in a pixel correction method of a projection image display image according to the present invention.

4 is a view for explaining the tilt angle correction state of the pixel driving element in the pixel correction method of the projection image display image according to the present invention.

* Explanation of symbols for main parts of the drawings

10: control unit 12: pixel correction data storage unit

14: pixel correction data buffer 16: data conversion unit (ADC)

18: pixel correction unit 20: data inverse conversion unit (DAC)

22: AMA driver 24: AMA panel

30: light source 32: source stop member

34: reflection mirror 36: field lens

38: light receiving element 40: pixel tilt angle detection unit

42: pixel tilt angle determination unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pixel correction method of a projection image display device. More particularly, when an image is displayed using an AMA panel, an initial tilting angle or tilting offset value of a plurality of AMA elements constituting the AMA panel is measured. The present invention relates to a pixel correction method of a projection type image display device which ensures uniformity of image quality by causing image projection to be performed while the measured tilting angle is shown.

As is well known, an image display apparatus is roughly divided into a direct type display apparatus represented by a CRT apparatus and a projection display apparatus represented by a liquid crystal display (LCD) element.

Among them, the CRT display device of the direct-view display device implements a color image by impinging a pixel on the fluorescent panel with the R / G / B color beam emitted from the R / G / B electron gun according to the color component of the image signal deflected. However, the CRT device not only needs the flow distance of the R / G / B color beam, but also restricts the implementation of the large screen.

In addition, although the LCD device of the projection display device can realize a relatively large screen but can be light and thin, the light loss due to the polarization piece is increased and the light efficiency is considerably low.

In view of the above, a projection image display device using an Actuated mirro array (AMA) panel has recently been proposed by AURA in the United States of America, and the AMA elements provided in the AMA panel are actuated by a pixel drive signal. The tilting degree is determined by the actuator and the action of the actuator is configured to include a reflection mirror for modulating the light reflection angle. That is, when the actuator performs an actuating action by a pixel driving signal applied to a pixel driving element incorporated in the active matrix substrate, the reflection mirror formed on the actuator reflects light from the light source, By contrasting the R / G / B color components and projecting them on the screen through the projection lens, a color image can be realized.

However, according to the projection type image display device employing such an AMA panel, the AMA element provided in the AMA panel corresponding to the number of pixels does not have a tilting offset value when the reflection mirror for light reflection or light modulation initially has any tilting offset value. The actuator acts in response to the driving signal enables accurate optical modulation. However, if the actuator or the reflecting mirror has a tilting angle as an initial offset value due to an error in the manufacturing process of the AMA element, for example, the pixel driving signal cannot be responded to. Excessive light modulation or insufficient light modulation is caused, and thus the image quality of the color image projected on the screen is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and measures an initial tilting angle of an AMA element provided in an AMA panel, sets a correction value for the tilting angle of the measured AMA element, and sets the correction value to the pixel driving signal when driving the pixel. It is an object of the present invention to provide a pixel correction method of a projection type image display device for adding and causing accurate light modulation.

In order to achieve the above object, according to a preferred embodiment of the present invention, a projection type for forming an image signal by optical modulation of the optical modulation element by adopting an AMA panel in which an optical modulation element (AMA element) corresponding to the number of pixels is formed In the image display apparatus, a test voltage is applied to the optical modulation device in a switching manner to measure minimum and maximum tilting angles, and pixel correction data is based on the measured minimum and maximum tilting angles and linearity of the input voltage. There is provided a pixel correction method of a projection type image display device configured to drive an optical modulator by adding the created pixel correction data to a pixel drive signal.

Preferably, the measurement of the initial tilting angle of the optical modulation device is irradiated with light reflected from the light source to the optical modulation device of the AMA panel to which a test voltage is applied, and the amount of light reflected from the optical modulation device received by the light receiving device The electrical signal is detected, and the detected electrical signal is compared with the reference potential to obtain the comparison result at an initial tilting angle.

In addition, the test voltage for the minimum tilting angle of the optical modulation device is applied to the zero potential, the test voltage for the maximum tilting angle of the optical modulation device is applied to the maximum small drive potential.

According to the pixel correction method of the projection type image display device according to the present invention, the zero potential and the maximum small driving potential are switched to be applied to measure the initial tilting angle in the state of irradiating the light modulation element of the AMA panel with the light emitted from the light source. The minimum and maximum tilt angles are measured, and the pixel correction data is generated based on the measured minimum and maximum tilt angles and the linearity of the input voltage and added to the pixel driving signal to perform pixel driving. The device is prevented from performing excessive and insufficient light modulation by the initial tilting angle.

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

1 is a block diagram of a projection type image display apparatus to which a pixel correction method is applied to the present invention. Reference numeral 10 denotes a pixel drive control signal based on horizontal and vertical synchronization signals (Hsync / Vsync) of an image signal. And a control unit for controlling pixel correction, 12 denotes a pixel correction data storage unit storing pixel correction data, which is created according to the present invention and to which the pixel driving signal is added, and 14 denotes the control unit 10 under the control of the control unit 10. The pixel correction data buffer in which the pixel correction data read out from the pixel correction data storage unit 12 is temporarily stored is shown.

16 shows a data converting section consisting of, for example, an analog-digital converter for converting a video signal subjected to gamma correction by an image signal processing means (not shown) into digital data, and 18 indicates that the digitally converted image data is converted into the pixel correction data buffer. Pixel correction is performed by performing pixel correction by matching pixel correction data applied in (14) on a pixel-by-pixel basis, and 20 denotes, for example, a digital conversion process for inversely converting image data corrected by the pixel correction 18 into analog data. A data inverse converter consisting of an analog converter is shown.

22 denotes an AMA driver which is applied to the AMA panel 24 which performs light modulation on the basis of the image signal analog-converted by the data inverse conversion unit 20 to form an image to be projected on the screen.

Here, the pixel correction data stored in the pixel correction data storage unit 12 in the pixel correction method of the projection image display device according to the present invention will be described in detail with reference to FIGS.

First, in order to measure the initial tilting angle of each AMA element 24a of the AMA panel 24, reference numeral 30 in FIG. 2 is applied to the AMA element 24a of the AMA panel 24. Shaped while passing through the source stop member 32 of the white light emitted from the light source indicated by the shape, the shaped light is redirected in the reflection mirror 34 is provided on the AMA panel 24 through the field lens 36 The AMA element 24a serving as a light modulator element of a large number (ie, corresponding to the number of fire water) is irradiated.

Then, the light reflected from the AMA element corresponding to the pixel of the image is incident on the light receiving element (or CCD imaging element) through the field lens 36 and output as an electric signal from the pixel tilting angle detector 40 to the pixel tilting. The reference potential Vref applied to the angle determiner 42 and externally applied to the pixel tilt angle detection signal in the pixel tilt angle determiner 42 is a potential for the horizontal flatness required for the AMA element. The minimum tilting angle of each AMA device is calculated.

Subsequently, a maximum driving voltage is applied to the AMA element 24a of the AMA panel 24 to measure the maximum tilting angle of each AMA element 24a of the AMA panel 24. The angle is measured.

Here, the relationship between the tilting angle of the AMA element 24a and the pixel driving voltage subjected to the gamma correction processing in the signal processing is shown in FIG. 3 when the pixel driving voltage is 'V0'. When the pixel driving voltage is 'V1', the tilt angle corresponds to 'A1'.

Therefore, when the AMA element 24a has an initial tilting angle of, for example, 'A0' in FIG. 4, the pixel correction data storage unit 12 adds a voltage of 'V1-V0' to the image signal, thereby adding the AMA element. Pixel correction data is stored so that the minimum tilt angle of 24a is maintained at 'A1', and such pixel correction data is formed for the entire AMA element 24a provided in the AMA panel 24.

In such a state, the control unit 10 is provided with the horizontal and vertical synchronization signals (Hsync / Vsync) of the image signal, and the image signal is applied to the data conversion unit 16 to convert the digital data into the pixel correction unit ( 18 is applied to the pixel correction data storage unit 12 by the address AD and the read control signal R for pixel designation generated based on the horizontal and vertical synchronization signals. After reading out the stored pixel correction data, the pixel correction data buffer 14 is buffered by the address AD and the write control signal W '.

Subsequently, the controller 10 applies the pixel correction data to the pixel correction unit 18 by an address AD specifying a pixel to be corrected and a read control signal R. Accordingly, the pixel is adjusted. The correction unit 18 performs a pixel correction process on the corresponding pixel by adding the voltage of the pixel driving signal and the voltage of the pixel correction signal applied to maintain the tilting angle of 'A1' described in FIG. The pixel-corrected image signal is inversely converted into an analog image signal by the data inverse conversion unit 20 and applied to the AMA element 24a which is a pixel driving element of the AMA panel 24 through the AMA driver 22. Accordingly, the light modulation operation is performed in a state where the initial tilt angle of the AMA element 24a of the AMA panel 24 is corrected.

As described above, according to the pixel correction method of the projection type image display apparatus, the pixel driving is performed by measuring the initial tilting angle of the AMA element provided in the AMA panel and setting a correction value for the measured tilting angle of the AMA element. Since the correction value is added to the pixel drive signal to drive the AMA device, the influence of the initial tilting angle of the AMA device is excluded, so that accurate optical modulation can be executed, and thus the image quality projected on the screen can be made uniform. have.

Claims (3)

A projection type image display apparatus which employs an AMA panel 24 having an optical modulation element (AMA element 24a) corresponding to the number of pixels to form an image signal by optical modulation of the optical modulation element 24a. The test voltage is applied to the optical modulation device 24a in a switching manner to measure the minimum and maximum tilt angles, and the pixel correction data is prepared based on the measured minimum and maximum tilt angles and the linearity of the input voltage. A pixel correction method for a projection type image display device, characterized in that the optical modulation element (24a) is driven by adding the created pixel correction data to the pixel drive signal. 2. The measurement of the initial tilting angle of the optical modulation device 24a is performed by irradiating light reflected from the light source to the optical modulation device of the AMA panel 24 to which a test voltage is applied. A projection type image, characterized in that the amount of light reflected at 24a is received by a light receiving element and detected as an electrical signal, and the detected electrical signal is compared with a reference potential to obtain the comparison result at an initial tilting angle. Pixel correction method of display device. 3. The test voltage for the initial tilting angle of the optical modulator 24a is applied to the zero potential, and the test voltage for the maximum tilting angle of the optical modulator 24a is maximized. A pixel correction method of a projection type image display device, characterized in that the driving potential is applied.