KR100188215B1 - Asymmetric picture compensating control method for projector - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling asymmetric screen correction of a projection type image display system, comprising: a projection type image display system for projecting an image signal processed by an image processing means onto a screen, the projection angle of the image signal projected on the screen; According to the corresponding correction amount control signal, the amount of missing pixels for image correction is determined in the horizontal scanning period, and the memory recording / clock of the image signals is set with an overall delay time set for the image signal for which the missing amount of pixels is determined. Generates a signal and controls the generation of a memory write / clock signal for missing the pixel with an equal delay time set to the image signal as a whole, thereby performing memory write / read of the image signal so that the pixel missing process is executed. And blanking data is inserted at a missing pixel position of the memory-read image signal. In this case, the published image signal is obtained by analog converting the image signal data into which the blanking data is inserted.

Description

Asymmetric Image Correction Control Method of Projection Image Display System

1A to 1F illustrate a process in which an asymmetric screen is projected in a projection image display system.

2 is a block diagram showing an asymmetric screen correction apparatus of a projection type image display system to which the asymmetric screen correction control method according to the present invention is applied.

3 is a waveform diagram for explaining correction control of an asymmetric screen executed by the asymmetric screen correction apparatus of the projection image display system shown in FIG.

4 (a) to 4 (e) are diagrams illustrating a screen correction process by the asymmetric screen correction apparatus of the projection image display system shown in FIG.

* Explanation of symbols for main parts of the drawings

10: Projection type image display system (projector)

20: screen 40: control unit

50: correction control signal generation unit 60: first switching unit

70: data memory (FIFO memory) 80: second switching unit

90: third switching unit 100: data conversion unit

The present invention relates to a control method for asymmetric screen correction of a projection image display system. More particularly, the delay time is equally preset for an image in which the upper and lower portions of the screen are asymmetrical depending on the installation inclination of the projection image display system. The asymmetric screen correction control method of the projection type image display system for the normal form of the screen projected on the screen by the reverse correction process in the set state.

An image display system for displaying color images includes a direct-view image display system represented by a CRT apparatus and a projection image display system represented by an LCD apparatus, among which a CRT apparatus radiates from an R / G / B electron gun. It is difficult to enlarge the color image due to the restriction on the size due to the flow distance of the color beam projected on the fluorescent panel, and since the LCD device uses the response of the liquid crystal to the color image signal, Although it is possible to make the thinner and thinner, the loss of light due to the polarizing panel is disadvantageous.

Therefore, in order to realize a large screen, color image signals are separated into R, G, and B color components, and the separated R, G, and B signals are conventionally adjusted to the color components of the color image, and then the optical lens is controlled by a projection lens. Projection type image display systems called "projectors" that display on the screen in an enlarged state to realize a large screen have been put into practical use.

By the way, according to such a projection type image display system, as shown in FIG. 1A, the center of the image projected on the screen 20 in the projection lens 10a of the projection type image display system 10 (hereinafter referred to as a projector) When the axis 30 is substantially horizontal, the projection distances L1 and L2 between the upper side and the lower side of the image are equalized from the center axis 30 of the screen, so that the image in the form shown in FIG. A normal image of approximately equal lengths of the upper and lower portions of is projected onto the screen 20.

On the other hand, when the projection lens 10a of the projector 10 is installed with a constant inclination angle (or projection angle) with respect to the screen 20 as shown in FIG. 1 (c) or FIG. 1 (e). In the image projected on the screen 20 from the projector 10, the upper portion and the lower portion are asymmetrical with respect to the central axis 30.

For example, when the projector 10 is installed to maintain an upward inclination angle with respect to the screen 20 as shown in FIG. 1C, the image projected on the screen 20 from the projector 10 is the center thereof. The distances L1 'and L2' of the upper and lower portions of the image with respect to the axis 30 are different from each other, so that the image projected on the screen 20 is reversed as shown in FIG. It becomes asymmetric screen of rhombus shape.

In addition, when the projector 10 is installed to maintain a downward inclination angle with respect to the screen 20, for example, as shown in FIG. 1 (e), the image projected on the screen 20 is applied to the central axis 30 thereof. The distances L1 and L2 of the upper portion and the lower portion are different from each other, and are projected on the screen 20 in a rhombus shape as shown in FIG.

Therefore, when the projector 10 is installed to have an upward or downward inclination angle with respect to the screen 20, when the screen projected on the screen 20 becomes asymmetric, the visual perception of the enlarged projection screen is reduced. Since it is reduced, it is necessary to correct the screen which is asymmetrical depending on the inclination angle of the projector. When correcting the screen to be asymmetrically projected, the corrected amount of the asymmetric screen is calculated according to the inclination angle (or the projection angle) of the projector 10 with respect to the screen 20, and the lower surface which is slowly reversely corrected for the screen to be projected is obtained. In order to display such an asymmetrical screen, a large number of hardware is used to determine the total number of scanning lines and to perform the missing (or omitting) processing of pixels for each scanning line along the correction direction. It is easy to set the screen correction timing due to delay or the like.

The present invention has been made in view of the above circumstances, and after calculating the amount of missing (or omitted) pixels for correction per scanning line of an asymmetrical screen programmatically with respect to the inclination angle (or projection angle) of the screen projected on the screen. Asymmetric screen correction control method of a projection type image display system for setting a uniform time delay and preliminarily correcting an asymmetric screen by missing pixels corresponding to the correction amount so that a normal screen is formed when the image signal is projected on the screen. The purpose is to provide.

In order to achieve the above object, according to a preferred embodiment of the present invention, in a projection type image display system for projecting an image signal processed by an image processing means on a screen, it corresponds to the projection angle of the image signal projected on the screen. According to the correction amount control signal, the missing amount of the appeal for the correction of the image is determined in the horizontal scanning period, and the memory recording / clock signal of the image signal is set with a total delay time set for the image signal for which the missing amount of the pixel is determined. And memory write / read of the image signal to control the generation of the memory write / clock signal for the missing of the pixel with the equal delay time set to the image signal as a whole. Blanking data is inserted into a missing pixel position of the memory read image signal. The asymmetrical screen correction control method is provided in a projection type image display system which obtains a published image signal by analog-converting image signal data into which blanking data is inserted.

According to such a correction control method of a projection type image display system according to the present invention, if an inclination angle (or projection angle) with respect to an image signal projected on a screen is specified as a correction control signal, the pixel is missing depending on the correction direction corresponding to the correction control signal. Determine the amount, set the equal delay time (i.e., the entire screen has a uniform delay time) in units of the determined scanning lines, and insert the blanking data at the pixel missing position to It will execute the presentation about the projection angle.

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

2 is a block diagram of an asymmetric screen correction apparatus (i.e., projector) of a projection type image display system to which another asymmetric image correction control method is applied, and reference numeral 40 denotes a projection angle (inclined angle) of an image signal. A control unit as a control means for controlling the display processing of the image signal according to, for example, a correction control signal provided from a control signal input means (for example, a remote controller) or a projection angle measurement means capable of automatically measuring the projection angle, The control unit 40 includes a correction control signal (KEY DATA) and a vertical synchronization signal (Vsync) and a horizontal synchronization signal (specified) of the image signal specified in a state where the projection image display system (hereinafter referred to as a projector) is installed at an upward or downward projection angle with respect to the screen. Hsync) provides a write / read control signal of the image signal to control the release processing of the image signal.

That is, when the image signal is designated as the upward projection angle with respect to the screen, the controller 40 determines the number of pixels that must be omitted in units of lines along the correction direction so that a screen having a shape opposite to the image projected during the upward projection is formed. The timing of the recording / reading signal for the omission of the image signal is determined for the pixel-deleted line unit, and 1 / time of the maximum correction amount at the time of reading the image signal recorded for the timing determination. After setting the delay time so that 2 is delayed, missing pixels are performed so that the correction data is formed at regular intervals at all times.

50 is a correction control signal for receiving the main clock signal fs and the DSP clock signal DSPCLK based on the write / read control signal provided from the controller 40 to generate a write / read clock signal of the image signal data. As a generation unit, the correction control signal generation unit 50 controls a predetermined number of scan lines in units of scan lines along the direction of correction of the image with a delay time corresponding to one-half of the correction amount as a whole under the control of the control unit 40. In addition to generating a write clock signal WCLK for controlling memory recording of the image signal data so that pixels are missing, a predetermined time (maximum correction amount / 2, for the image signal data recorded by the write clock signal WCLK) is generated. Precisely, the read clock signal RCLK is generated with a delay of the maximum correction amount / 2 + the correction amount / 2 for each block / 2).

60 is a first switch that provides a switching clock signal WCLK and a read clock signal RCLK provided from the correction control signal generation unit 50 by a control signal C provided from the control unit 40. The switching part is shown.

70 is an image signal data DATA provided in response to the horizontal synchronization signal Hsync based on the write control clock signal WCLK and the read control clock signal RCLK provided through the first switching unit 30. Is a data memory for storing or outputting the stored image signal data DATA. Preferably, the data memory 40 is constituted by a first-in first-out (FIFO) type memory or a buffer of image signal data of one line. The data memory 70 writes in such a way that pixels are reduced line by line along the correction direction of the image based on the write control clock signal WCLK, i.e., the image signal data is missing (removing the pixel data). The image signal data recorded in the data memory 70 is added to the read control clock signal RCLK having a normal clock speed provided by the correction control signal generation unit 50 under the control of the control unit 40. As a result, it is read out at the passage of (maximum correction amount / 2 + block correction amount / 2) as described later.

80 is set in front and rear of the image signal data read out by the read clock signal RCLK in the state stored in the data memory 70 and the pixel missing processed image signal data to perform an image display process. A second switching unit for switching and outputting unranked data for filling the unranked area under the control of the controller 40 is shown.

Also, 90 is corrected by the data conversion output signal NCLK having a time delay of maximum correction amount / 2 compared to the normal horizontal DSP clock signal generated by the correction control signal generation unit 50 under the control of the control unit 40. A third switching section for switching and outputting the data conversion output signal NCLK so that data conversion output of the image data is performed.

An elapsed time point of the maximum correction amount / 2 is 100 when the image signal data including the blanking data provided from the second switching unit 80 based on the data conversion output signal NCLK switched by the third switching unit 90. The data conversion section outputs data by converting data (analog conversion).

Next, the asymmetric image correction control method of the projection type image display system according to the present invention will be described in detail with reference to the timing chart shown in FIG. 3 and the fourth drawings (a) to (e).

First, when the image is projected on the screen in the form of maintaining the upward projection angle, a correction control signal (KEY DATA; that is, the projection angle) corresponding to the upward projection angle is input, for example, from a remote controller or a projection angle specifying means. 40), in response to the correction control signal, performs control of the display processing of the asymmetric screen so that a normal screen (see FIG. 4 (a)) is projected on the screen. In this case, since the screen projected on the screen exhibits an inverted diamond shape, the controller 40 controls the image signal to be processed in a rhombus shape.

That is, when the correction amount is determined according to the correction control signal KEY DATA, the controller 40 determines the number of pixels to be omitted for each scan line.

When the number of missing pixels is determined by the control unit 40, the correction control signal generation unit 50 is controlled so as to be generally uniform from the clock signal Dspclk (refer to FIG. 3 (b)) input for displaying an image. A write / read control signal is generated such that the write / read clock signal WCLK / RCLK is generated to the data memory 70 of the image signal for the above-mentioned calcination elimination process with a delay time (i.e., the maximum correction amount / 2). The first switching unit 60 in which the switching path is formed under the control of the control unit 40 is applied to the write clock signal WCLK and the read clock signal RCLK generated by the correction control signal generation unit 50. Is applied to the data memory 70 via.

Therefore, the image signal data applied to the data memory 70 based on the horizontal synchronizing signal HSYNC includes a period A for missing the pixels applied through the first switching unit 60 during recording. Based on the written clock clock signal WCLK (see FIG. 3C), the data is written line by line into a data memory 70 made of, for example, a FIFO memory.

The image signal data recorded in the data memory 70 is read out based on the extraction clock signal RCLK (refer to FIG. 3 (d)) applied through the first switching unit 60 at the time of reading. The read clock signal RCLK is generated in a state where a pixel is missing (i.e., correction amount) and a maximum correction amount / 2 delay time is set at a position that is a target of pixel leakage calculated by the above equation. The data of the image signal output from the data memory 70 is stolen by the read clock signal RCLK while the missing amount of the pixel and the delay time are set, and the image signal data is switched and controlled by the controller 40. The blanking data applied through the second switching unit 80 is added to the position of the maximum correction amount / 2 in the state where the correction amount is set for each correction line by the horizontal scanning period HDSP 'shown in FIG. 3 (f)).

Accordingly, in the data conversion unit 100, the data conversion output signal NCLK provided with a time of a delay of m / 2 generated by the correction control signal generation unit 50 is controlled under the control of the control unit 40. 3, when applied via the switching unit 90, the image signal data to which the blanking data is added is analog-converted and applied to the projector as a corrected image signal, and as a result, the screen shape when projected upward on the screen (FIG. 4) (b) data in the form of the screen shown in FIG. 4 (c), which is inversely corrected, is formed, analog-converted by the data converter 100, output as corrected image data, and post-processed to be projected on a screen. Accordingly, even in the case of upward projection, a normal screen form (see FIG. 4A) is displayed on the screen.

On the other hand, in the case of the downward projection, the correction is performed while dropping the number of pixels in the reverse direction as in the case of the upward projection, and accordingly, the shape of the screen to be projected on the screen during the projection (Fig. 4 (d)). Since the screen form of FIG. 4 (e) reversely corrected is obtained, the screen form of FIG. 4 (a) is displayed on the screen during the downward projection.

As described above, according to the asymmetric screen correction control method of the projection-type image display system according to the present invention, an image in which the asymmetric state of the screen projected on the screen in advance is corrected based on the projection angle of the image to be projected on the screen. By processing it as a signal and projecting it on the screen, a normal screen is obtained as a result, so that deterioration of visual perception can be prevented.

Claims (1)

A projection type image display system for projecting an image signal processed by an image processing means onto a screen, the pixel for correcting an image in a horizontal scanning period in accordance with a correction amount control signal corresponding to the projection angle of the image signal projected on the screen. Determine a missing amount of the pixel, generate a memory write / clock signal of the image signal with an overall delay time set for the image signal for which the pixel missing amount is determined, and set an overall delay time for the image signal In this state, memory write / read of the image signal is performed to control the generation of the memory write / clock signal leading to the missing pixel, so that the pixel missing process is executed, and blanking data at the missing pixel position of the memory read image signal. Is inserted, and the blanking data is inserted into the analog image signal data. Asymmetry correction screen control method of a projection type image display system, characterized in that the write line so as to obtain a corrected image signal.