KR100878956B1 - Controller of the resolution in the display system using the diffractive optical modulator - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a resolution adjusting apparatus that enables to adjust such a difference when an input resolution and an output possible resolution differ in a display system using a diffractive optical modulator.

Diffraction Optical Modulator, Resolution, Input Resolution

Description

Controller of the resolution in the display system using the diffractive optical modulator

1 is a conceptual diagram illustrating a problem caused by a difference between an input image resolution and an output image resolution in a display system using a diffractive optical modulator according to the prior art.

2 is a block diagram of a display system using a diffraction type optical modulator with a resolution adjustment function according to an embodiment of the present invention.

3 is a block diagram of a resolution adjusting device in a display system using a diffractive optical modulator according to an embodiment of the present invention.

4 is a flowchart illustrating a resolution adjusting method in a display system using a diffractive optical modulator according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a resolution change when an input resolution is n and an output resolution is n / 2 according to an embodiment of the present invention. FIG.

FIG. 6A is a diagram illustrating a sudden change type of gradation between pixels according to an embodiment of the present invention, and FIG. 6B is a diagram illustrating a gradual change type of gradation between pixels according to an embodiment of the present invention.

7 is a block diagram illustrating an internal block of the image correction unit of FIG. 3.

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

202: display optical system 204: display electronic system

206: light source 208: illumination optical unit

210: diffractive optical modulator 212: projection unit

216: filter optics 218: screen

310: image input unit 320: image pivot unit

330: Image data storage unit 340: Image correction unit

350: image data output unit 360: optical modulator driving circuit

720: original image input unit 722: inter-pixel gradient calculator

724: Pixel allocator for the original image

726: pixel value generator

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a resolution adjusting apparatus that enables to adjust such a difference when an input resolution and an output possible resolution differ in a display system using a diffractive optical modulator.

As a next-generation display device, research on various flat panel displays (FPDs) has been actively conducted, among which generalized display devices include liquid crystal displays (LCDs) using electro-optic characteristics of liquid crystals, and gases. And a plasma display panel (PDP) using discharge.

Among them, a liquid crystal display device (hereinafter, abbreviated as "LCD") has a narrow viewing angle and a slow response time, and requires a thin film transistor (TFT) and an electrode using a semiconductor manufacturing process. There is a difficulty.

Plasma display panel (PDP) has the advantage that the manufacturing process is simple and advantageous to large area, but the power consumption is large, and the discharge and luminous efficiency is low and expensive.

The development of a new display device that can solve the problems of the flat panel display device is in progress, and recently, the pixel (Pixel) using a micro electromechanical system (hereinafter, abbreviated as "MEMS") is an ultra-fine processing technology. A display device capable of displaying an image by forming a fine spatial light modulator (SLM) has been proposed.

Here, the spatial light modulator (SLM) is a converter for modulating the incident light beams in a spatial pattern corresponding to the electrical or optical input. Incident light can be modulated in its phase, intensity, polarization or direction, and light modulation can be achieved by various materials with various electro-optic or magneto-optic effects, and by materials that modulate the light by surface modification. have.

On the other hand, the diffraction type optical modulator described above can be used in various applications, for example, it can be used in a display device.

However, when the display system using the diffractive optical modulator described above is used in a portable device, since the resolution of the image provided by the portable terminal device is low resolution, when the inputted image is projected as it is, the high resolution is lower than the screen size. There is a problem that it is difficult to obtain image quality.

That is, in the case of a display device generally used in a portable terminal device, the image resolution input to the display device due to lack of video communication capacitor and small screen size is 176 * in the case of QCIF (Quarter Common Intermediate Format). For 144 resolution, 352 * 288 resolution is provided for CIF (Common Intermediate Format) method, and 320 * 240 resolution for QVGA (Quarter Video Graphics Array) method.

In this case, there is no problem in the QCIF (Quarter Common Intermediate Format) method to realize the resolution of 176 * 144 using a diffractive optical modulator, but the CIF (Common Intermediate Format) method or QVGA (Quarter Video Graphics Array) method In this case, it is necessary to lower the resolution.

Referring to FIG. 1, when the vertical resolution of the image input to the display device of the portable terminal device is v and the number of pixels that the diffractive optical modulator can form is p <v, it is necessary to adjust the resolution of the input image. have.

Accordingly, the present invention has been made to solve the above problems, in the case of a display system using a diffractive optical modulator when the input resolution and the output resolution is different, it is possible to adjust such a difference to prevent image degradation. It is an object of the present invention to provide a resolution adjusting device.

An apparatus of the present invention for achieving the above object, in a display system including a light source system, an illumination optical unit, a diffraction type optical modulator, a projection and scanning optical unit, and a screen, input image data from the outside Receiving image input unit; An image correction unit converting the high resolution image data received by the image input unit into low resolution image data and outputting the converted high resolution image data; And an optical modulator driving circuit configured to generate a driving voltage for driving the diffractive optical modulator according to the image data output from the image correcting unit and to drive the diffractive optical modulator.

2, a resolution adjusting device in a display system using a diffractive optical modulator according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a block diagram of a display system using a diffractive optical modulator with a resolution adjustment function according to an embodiment of the present invention.

2, a display apparatus using a diffraction type optical modulator with a resolution adjusting function according to an exemplary embodiment of the present invention includes a display optical system 202 and a display electronic system 204.

The display optical system 202 includes a light source 206 that generates and emits light, and the light source 206 includes a vertical external cavity surface emitting laser (VECSEL) and a vertical resonance surface emitting laser (VCSEL). Light sources fabricated using semiconductors such as Cavity Surface Emitting Lasers, Light Emitting Diodes (LEDs), Laser Diodes (LDs), and Super Luminescent Diodes (SLEDs) may be used.

The light source 206 emits laser light. The cross section of the laser light is circular, and the intensity profile of the light has a Gaussian distribution. For example, the light source 206 (actually, the laser of the R light source and the G light source) Laser, B light source laser) can emit R light, G light, B light sequentially.

In addition, the display optical system 202 includes an illumination optical unit 208 to irradiate the light emitted from the light source 206 to the diffractive light modulator 210 as parallel light in a linear shape.

The illumination optical unit 208 converts the laser light emitted by the light source 206 into linear light having a long length and a narrow width, and then converts the laser light into parallel light and enters the diffracted light modulator 210.

The illumination optical unit 208 may be made of, for example, a convex lens (not shown) or may include a convex lens (not shown) and a collimating lens (not shown).

In addition, the display optical system 202 includes a diffractive light modulator 210 which diffracts the linear light irradiated from the illumination optical unit 208 to generate diffracted light having a plurality of diffraction orders in which the light intensity of the diffracted light is adjusted. .

Here, the diffracted light emitted by the diffractive light modulator 210 includes diffracted light having various diffraction orders such as 0th diffraction light, ± 1st order diffraction light, ± 2nd order diffraction light, ± 3rd order diffraction light, and the like. Odd-order diffraction light and even-order diffraction light differ in phase from each other by 180 degrees.

The diffracted light emitted by the diffractive light modulator 210 is a diffracted light having a long line shape and a narrow width.

 In addition, the diffracted light emitted by the diffractive light modulator 210 may include diffracted light corresponding to one pixel of an image formed on the screen 218 by diffracted light formed by one upper reflector and a lower reflector corresponding thereto. The diffracted light formed by the two or more upper reflectors and the lower reflector corresponding thereto may form diffracted light corresponding to one pixel formed on the screen 218.

Next, the display optical system 202 projects the diffraction light having a plurality of diffraction orders emitted from the diffractive light modulator 210 toward the screen 218 to perform scanning on the screen 218. ) Is included.

As such, the projection unit 212 performs scanning on the screen 218 by directing the diffracted light toward the screen 218. As an example of the projection unit 212, a projection lens (not shown) and the diffracted light are screened. And a scanner (not shown) that performs scanning to face 218.

The projection lens (not shown) consists of a combination of a plurality of convex lenses and a plurality of concave lenses, and serves to focus incident light so that the focus of the diffracted light is located on the screen 218.

The scanner (not shown) may be a galvanometer scanner or a polygon mirror scanner.

In addition, the display optical system 202 is positioned between the projection unit 212 and the screen 218 and transmits the diffraction light of the order desired to be used in the various orders of diffraction light projected from the projection unit 212 to the screen 218. It comprises a filter optical portion 216 to pass. As an example of the filter optical unit 216, slits may be used.

On the other hand, the display electromagnetic field 204 is connected to the light source 206, the diffractive light modulator 210, and the projection unit 212.

In this case, the display electronic field 204 adjusts the resolution of the image input from the outside to provide the driving voltage according to the adjusted resolution to the diffractive optical modulator 210. That is, the display electromagnetic field 204 adjusts to a low resolution when receiving an image having a 320 * 240 resolution of QVGA type, for example, and provides a driving voltage to the diffractive optical modulator 210 accordingly.

3 is a block diagram of a resolution adjusting device in a display system using a diffractive optical modulator according to an embodiment of the present invention.

4 is a flowchart of a resolution adjusting method in a display system using a diffractive optical modulator according to an embodiment of the present invention.

Referring to the drawings, in the display system using a diffractive optical modulator according to an embodiment of the present invention, the resolution adjustment device, the image input unit 310, the image input unit 310 receives the image data from the outside in the horizontal direction An image pivot unit 320 for performing data transposition for converting the image data arranged in the longitudinal direction, an image data storage unit 330 for storing image data transposed by the image pivot unit 320, and an image An image correction unit 340 for adjusting the vertical resolution of the image data that has been transposed from the pivot unit 320, an image data output unit 350 for outputting an image having the vertical resolution adjusted from the image correction unit 340, The optical modulator driving circuit 360 generates a driving voltage of the diffractive optical modulator according to the image data of the image data output unit 350.

Here, the image input unit 310 receives image data from an external device, and in the case of a portable terminal, receives image data from a baseband processor or a multimedia processor of the portable terminal (step S100).

In this case, when the image input unit 310 receives QCIF, an image of one frame includes a row length (K) = 144 pixels and a column length (L) = 176 pixels. The image consists of row length (K) = 288 pixels and column length (L) = 352 pixels.In the case of QVGA, the image of one frame has row length (K) = 240 pixels and column length (L) = 320 It consists of pixels.

At this time, the image pivot unit 320 performs a data transpose for converting the image data arranged in the lateral direction in the longitudinal direction, and converts the image data input in the lateral direction into the image data in the longitudinal direction (step S102). ). The reason why the data pivot is required in the image pivot unit 320 is that the scanning line emitted from the diffractive optical modulator is scanning corresponding to a plurality of pixels (for example, 480 pixels when the image data emitted is 480 * 640). This is because the diffracted point lights are arranged vertically so that they can be scanned and displayed in the horizontal direction.

As such, the image pivot unit 320 stores the image of the data transpose in the image data storage unit 330.

The image correction unit 340 is data transposed by the image pivot unit 320 and reads the type data of the image data stored in the image data storage unit 320 (step S104), and adjusts the vertical resolution to adjust the vertical. The resolution is output (steps S106 to 112).

An example of vertical resolution adjustment performed by the image corrector 340 is illustrated in FIG. 5. Referring to FIG. 5, the image correction unit 340 allocates any one of adjacent pixels when the slope between adjacent pixels is large in consideration of the slope between adjacent pixels of the original image in the image data stored in the image data storage 330. If the slope between adjacent pixels is small, the average value of adjacent pixels is calculated and assigned.

That is, if the difference between the upper pixel value and the lower pixel value between adjacent pixels is greater than or equal to a predetermined value, the image correction unit 340 does not allocate the upper pixel value or the lower pixel value as it is and does not assign an average value. After obtaining the difference between the pixel value of the pixel and the lower pixel, if the difference is less than a predetermined value, the average value of the upper pixel value and the lower pixel value is assigned. This is because, as shown in FIG. 6A, when the average value is assigned to a section in which the pixel and the pixel value change rapidly, the boundary may become unclear. Of course, assigning an average value or the like to a section in which the pixel and the pixel value slowly change, as shown in FIG. 6B, does not increase the uncertainty on the boundary. Accordingly, the image correction unit 320 of the present invention allocates an appropriate value to the remaining pixels in consideration of the sudden change of the pixel and the pixel.

This will be described with reference to the detailed block diagram of the image corrector 340 of FIG. 7.

First, the original image input unit 720 of the image corrector 340 reads the original image stored in the image data storage unit 330 (step S104), and the inter-pixel gradient calculator 722 is configured to control the pixel and the pixel. The amount of change in the pixel value is calculated, and the absolute value is obtained by subtracting the pixel value of the lower pixel of the residual pixel from the pixel value of the upper pixel between adjacent pixels to find the change amount of the pixel value of the pixel of the original image and the pixel (step S106). ). In this case, it is determined whether the gradient between the pixel calculated by the inter-pixel gradient calculator 722 and the pixel is greater than or equal to a predetermined value (step S108). The allocator 724 assigns pixel values for the remaining pixels (step S110). That is, referring to FIG. 5 as an example, in the case of pixel p = 1 of the output image data, if the value obtained by subtracting the pixel value assigned to v = 2 from the pixel value assigned to pixel v = 1 becomes a predetermined value or more, the pixel Assign p = 1 to the value of pixel v = 1 or v = 2.

On the other hand, if the pixel-to-pixel gradient calculated by the inter-pixel gradient calculator 722 is less than or equal to a predetermined value, the pixel value generator 726 generates a pixel value for the corresponding pixel (step 112).

In this case, the pixel value generator 726 may allocate an average value of the upper pixel value and the lower pixel value between adjacent pixels to the corresponding pixel by generating an image value to be assigned to the corresponding pixel. For example, referring to FIG. 5, in the case of pixel p = 2 of the output image data, the pixel value of pixel v = 2 and the pixel value of v = 3 are added, and then the average value obtained by dividing by 2 is allocated to pixel p = 2. .

In this case, when the pixel p = s of the output image data, when p = s and the slope between the pixel and the pixel is more than a predetermined value, the original image of v = 2s-1 (s is 1 to n) or v = 2s is allocated as it is. If the slope between the pixel and the pixel is less than or equal to a predetermined value, the pixel value for the pixel can be obtained by a combination of v = 2s-1 and v = 2s.

Meanwhile, the method of generating the pixel value by using the average value when the pixel value generator 726 of the image corrector 340 generates the pixel value has been described above. However, other methods are possible. There may be a way to make the weights different.

That is, when the pixel to be generated by the pixel value generator 726 of the image corrector 340 is the s-th pixel, the upper pixel is 2s-1 pixel and the lower pixel is 2s. You can set the weight differently like).

(Equation 1)

f (s) = w1 * f (2s-1) + w2 * f (2s)

Here, w1 and w2 represent weights.

Meanwhile, when the resolution of the input image data is 3n and the output resolution is n, the image correction unit 340 is as follows.

If the 3s-th row data of the input image data is f (3s), the 3s-1st row data is f (3s-1), and the 3s-2th row data is f (3s-2), s-th row data is assigned by selecting any one of f (3s), f (3s-1), and f (3s-2) in the abrupt change interval of the inter-pixel gradient, and when there is no sudden change of the inter-pixel gradient. Has [w1 * f (3s-2) + w2 * f (3s-1) + w3 * f (3s)] / 3, where w1, w2 and w3 are weights. Here, the method for finding the abrupt change interval of the inter-pixel gradient calculates the inclination between adjacent pixels with respect to three pixel values, and if any one section with a rapid rate of change is found in the value, it is determined that there is a sudden change in the inter-pixel gradient. do.

Generalizing this is as follows.

When the resolution of the input image data is mn and the output resolution is n, the image corrector 340 is as follows.

If the msth row data of the input image data is f (ms), the ms-1st row data is f (ms-1), and the ms-2nd row data is f (ms-2) or the like, the output image data The s-th row data of f (ms), f (ms-1), f (ms-2),... , f (ms- (ms-2)) or f (ms- (ms-1)), and select one of them. If there is no sudden change in the gradient between pixels, [wm * f (ms- ( ms-1)) + w (m-1) * f (ms- (ms-2)) + w (m-2) * f (ms- (ms-3)) +... w (m- (m-1)) * f (ms)] / m, and wm, w (m-1), w (m-2), and the like are weights.

On the other hand, the image data output unit 350 reads and outputs the image data corrected by the image correcting unit 340 (step S114).

The optical modulator driving circuit 360 applies an upper electrode driving voltage matched to the upper electrode layer of each of the diffractive optical modulators when the gray level is input from the image data output unit 350 to the image image data. It drives (step S116).

Meanwhile, the corresponding pixel allocator 724 and the pixel value generator 726 of the original image may be referred to as a pixel allocator. If the gradient calculated by the inter-pixel gradient calculator 722 is greater than or equal to a predetermined value, the original image is allocated. If the value is less than or equal to the predetermined value, pixels are generated and allocated using adjacent pixels.

According to the present invention as described above, when high resolution image data is input, there is an effect to easily implement a low resolution of the input image data.

In addition, according to the present invention, when the high resolution image data is input, it is possible to ensure the image data of a sufficient resolution by adjusting the appropriate resolution, it is possible to prevent the degradation of the image quality.

According to the present invention, when the resolution of the input image data is converted to the resolution of the output image data, the resolution can be changed in consideration of the amount of change between pixels to obtain a change in resolution having a clear boundary.

Claims (9)

A display system comprising a light source, an illumination optical unit, a diffractive optical modulator, a projection and scanning optical unit, and a screen, An image input unit which receives image data from an external source; An image pivot unit which performs a data transpose for translating the image data arranged in the horizontal direction inputted to the image input unit in the longitudinal direction to convert the image data input in the horizontal direction into image data in the longitudinal direction; An image correction unit which receives the image data formed by data transposing the high resolution image data received by the image input unit from the image pivot unit and converts the high resolution image data into low resolution image data; And And an optical modulator driving circuit configured to generate a driving voltage for driving a diffractive optical modulator according to the image data output from the image correcting unit, and to drive the diffractive optical modulator. The method of claim 1, And the image correcting unit corrects the vertical resolution in the high resolution image data to form low resolution image data. The method of claim 2, The high resolution image data input by the image input unit is one of a resolution of QCIF (Quarter Common Intermediate Format), a resolution of CIF (Common Intermediate Format), and a resolution of QVGA (Quarter Video Graphics Array). Resolution adjustment device. delete The method of claim 1, The image correction unit, An original image input unit which receives an image from the image input unit; An inter-pixel gradient calculator for calculating a slope between adjacent pixels in the image data received from the original image input unit; And And a pixel allocator configured to allocate an original image when the slope calculated by the inter-pixel gradient calculator is greater than or equal to a predetermined value and to generate and allocate pixels using adjacent pixels when the gradient is less than or equal to a predetermined value. The method of claim 5, wherein The pixel allocation unit, An original image corresponding pixel allocator for allocating the original image when the inter-pixel gradient calculated by the inter-pixel gradient calculator is greater than or equal to a predetermined value; And And a pixel value generator configured to generate and allocate a new pixel value by using adjacent pixels when the inter-pixel gradient calculated by the inter-pixel gradient calculator is less than or equal to a predetermined value. The method of claim 1, The image correction unit, When the resolution of the input image is 2n and the resolution of the output image is n, the output image data when the second row data of the input image data is f (2s) and the second row data is f (2s-1). The sth row data of f (s) selects and assigns one of f (2s) and f (2s-1) when the slope between adjacent pixels is equal to or greater than a predetermined value, and f (s) = when it is smaller than or equal to the predetermined value. and w1 * f (2s-1) + w2 * f (2s), wherein w1 and w2 are weights. The method of claim 1, The image correction unit, When the resolution of the input image is 3n and the resolution of the output image is n, the third row data of the input image data is f (3s), the third row data is f (3s-1), and 3s-2. If the first row data is f (3s-2), the sth row data of the output image data is equal to or smaller than f (3s), f (3s-1), and f (3s-2) if it is equal to or larger than a predetermined value of the inter-pixel gradient. Select one and assign it, and if the inter-pixel gradient is less than or equal to a predetermined value, it becomes [w1 * f (3s-2) + w2 * f (3s-1) + w3 * f (3s)] / 3, and w1 and and w2 and w3 are weights. The method of claim 1, The image correction unit, When the resolution of the input image is mn and the resolution of the output image is n, the msth row data of the input image data is f (ms), the ms-1st row data is f (ms-1), and the ms-2nd If the row data is f (ms-2) or the like, the s-th row data of the output image data has f (ms), f (ms-1), f (ms-2), … , f (ms- (ms-2)) or f (ms- (ms-1)) is selected and assigned, and when the inter-pixel slope is less than or equal to the predetermined value, [wm * f (ms- (ms -1)) + w (m-1) * f (ms- (ms-2)) + w (m-2) * f (ms- (ms-3)) +... and w (m- (m-1)) * f (ms)] / m, wherein wm, w (m-1), w (m-2), and the like are weighted.

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