KR100832052B1 - A display device, a display control device, a display method, a display control program, and a computer-readable recording medium recording the program. - Google Patents

Abstract

It is a display device which displays 1 pixel by a plurality of rectangular display elements.

Multi-gradation character generation units 4a and 4b for generating information on multi-gradation character images obtained by gradation of character edges, and the rectangular display elements of the display unit 2 based on the information on the multi-gradation character images. The element display control part 6 which controls the display state in the display part 2 is comprised so that 10 may be displayed corresponding to one or more pixels, respectively, and the quantization error is reduced and it is high definition. In the case of displaying characters, characters with good visibility can be displayed.

Display element, display device, character image, gradation, multi gradation, luminance value

Description

DISPLAY DEVICE, DISPLAY CONTROL DEVICE, DISPLAY METHOD, DISPLAY CONTROL PROGRAM, AND COMPUTER-READABLE RECORDING MEDIUM CONTAINING THE PROGRAM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a display device that displays one pixel by rectangular display elements of R (red), G (green), and B (blue), such as a color liquid crystal display device. A display device, a display control device, a display method, a display control program, and a computer-readable recording medium having recorded the program, which are suitable for use in displaying characters).

In recent years, as the weight reduction of the flat panel type display device (personal computer) represented by the liquid crystal color display device progresses, portable use is mainly used. Under these circumstances, display of high definition characters and color image display on a smaller screen is required.

In Japanese Patent Laid-Open No. 2002-91369 (Patent Document 1), when displaying high definition characters, for the purpose of displaying characters with good visibility, for example, R (red), G (green), and B (blue) In a color liquid crystal display device in which one pixel display is performed by a rectangular display element, a method of displaying a character image as a display target by mapping each rectangular display element to one or more pixels, respectively.

In the method disclosed in Patent Literature 1, in the character creation process by the rasterizer, a double value character image (binary character image) having a triple size is first obtained based on the font data. Then, the binary character image of the triple size is developed (mapped) in the coordinate system corresponding to each rectangular display element, and then smoothing is performed on this coordinate to grayscale each pixel, thereby recovering the character edges. (jaggy, jagged shape) is reduced, and a character image is displayed by making each rectangular display element correspond to three pixels, respectively.

Generally, when displaying characters with a portable electronic device such as a cellular phone or PDA (Personal Digital Assistants), a character size of about 3 mm is considered to be optimal. In addition, at present, most commercially available liquid crystal displays (liquid crystal panels) have a screen resolution of about 180 dpi (dot per inch). When such a liquid crystal panel having a screen resolution of about 180 dpi is subjected to character display using a method of enlarging the character image disclosed in Patent Document 1 above by 3 times, the resolution level is about 500 dpi, which is 3 mm. It can be said that the character image of the degree is displayed with a resolution of about 60 dots x 60 dots.

However, in the conventional method described above, when a binary character image is mapped to each rectangular display element, distortion may occur in the character image due to quantization error.

Generally, fonts developed for printing (printing fonts) are created using a mesh of 1000 to 10000 dpi or more. Then, in order to accurately express, for example, a 3 mm character image using such a printing font, dots of about 120 to 1200 dpi per character are required. However, in the liquid crystal displays generally marketed as described above, in order to accurately reproduce the font for printing, resolution is insufficient, and as a result, when a character image is displayed using the conventional method, Distortion may occur in the direction of misalignment or stroke width of the connection position, resulting in deterioration of character quality.

For example, in the case of displaying a complex character such as a Japanese character, the character stroke width (line width) or the distance between the line forming the character and the line may be about one dot. And when generating a binary character image, depending on the precision of a character generation process, a stroke position may shift | deviate by a dot unit. When deviation of such a stroke position occurs, distortion may arise especially in the connection position of the lines which comprise a character, and the deterioration of a character quality may be outstanding.

19A and 19B are diagrams for explaining the distortion of characters in the conventional character image display method. FIG. 19A is a diagram showing an example of a character image without distortion, and FIG. 19B shows an example of a character image with distortion. It is a figure. As shown in Fig. 19B, distortion may occur at a position where lines constituting letters are connected.

In addition, when the character stroke width (line width) is about one dot, the stroke width may be two dots depending on the stroke direction depending on the precision of the binary character image generation process. By projecting the binary character image configured in this way into a rectangular coordinate system for developing on a rectangular display element, distortion may occur in the stroke width depending on the stroke direction (see width A and width B in FIG. 19B).

20A and 20B are diagrams for explaining character distortion in the conventional character image display method, and FIG. 20A is a diagram showing an example of a character image in a state in which no distortion occurs before projecting on a Cartesian coordinate system, and FIG. 20B is a diagram. It is a figure which shows the example of the character image which the distortion which projected the character shown in 20a to a Cartesian coordinate system, and has shown the resolution lower than actual in order to make it easy to see the state which a distortion produced. As shown in this Fig. 20B, distortion occurs at the connection position (for example, the connection position of the right oblique line of "林").

In general, an outline font (printing font) is composed of data describing the outline of a character, and based on the outline information, a character outline is generated according to the required character size, and the pixel in the outline is converted into a black value (0). By filling, a character image (glyph) is created.

If the character outline information can be generated at the same level of resolution as when designing a font describing the character outline, there is no deterioration in the character quality, but when the resolution at the time of generation is low, depending on the precision of reproducing the outline Since the designed coordinate values do not necessarily coincide with the generated coordinate values, the stroke has the same distortion as described above.

SUMMARY OF THE INVENTION The present invention was developed in view of the above problems, and has a display device, a display control device, a display method, a display control program, and a display device, a display control device, a display control program, and a display device which reduce the quantization error so as to display characters having good visibility when displaying high definition characters An object of the present invention is to provide a computer-readable recording medium having recorded the program.

<Patent Document 1>

Japanese Patent Laid-Open No. 2002-91369

In order to achieve the above object, the display device of the present invention uses N rectangular display elements (N is a natural number of two or more) capable of displaying different colors, and the longitudinal direction of the rectangular display elements is a predetermined arrangement direction. Is formed by successively repeating a predetermined sequence in the arrangement direction in a state orthogonal to each other, wherein the N display elements arranged in the predetermined sequence in the arrangement direction correspond to one pixel forming a display target image. A multi-gradation character generation unit for generating information on a multi-gradation character image obtained by graying the edges of characters based on the display unit capable of performing the operation, and character information on the display target character; An element display control unit for controlling the rectangular display elements forming the display unit to control the display state on the display unit; , The multi-tone based on information relating to the character image, characterized in that the each of the rectangular display device displays all the more so as to correspond to one pixel gradation character image, respectively.

On the other hand, the multi-gradation character generating unit uses the N rectangular display elements to store M (M is a natural number) times in the length direction and N times the size in the arrangement direction with respect to the character size of the display target character. Generating the enlarged character image information relating to the enlarged character image for display by causing one-pixel display, and based on the enlarged character image information generated by the multi-gradation character generation unit, One rectangular display element is associated with each pixel column consisting of M pixels continuous in the longitudinal direction, and a luminance value for the one rectangular display element is based on a pixel value given to each of the M pixels. And an element luminance value calculating unit for calculating the element luminance value calculating unit. It controls the respective rectangular display element according to a calculating the luminance value, may be displayed to the enlarged character image on the display unit as the character size.

Further, in the display section, the N rectangular display elements arranged in a predetermined order in the arrangement direction form a substantially square rectangular element, and the multi-gradation character generating unit is adapted to the character size of the display target character. Image information of the same character having a size of 1 times in the longitudinal direction and N times in the arrangement direction may be generated as the enlarged character image information.

In addition, the element luminance value calculation unit is further configured to provide the rectangular display element based on overlapping information between the rectangular display elements and the enlarged character image in a rectangular image coordinate system formed corresponding to the rectangular display element. The luminance value for the rectangular display element may be calculated or the element luminance value calculation unit may calculate the luminance value for the rectangular display element based on the area information of the enlarged character image overlapping the rectangular display element.

The element luminance value calculating unit may calculate the luminance value for the rectangular display element based on the reapproach distance between the center of each rectangular display element and the outline in the enlarged character image overlapping the rectangular display element. Further, the luminance value of the rectangular display element may be calculated based on the reapproach distance between the center of gravity of each rectangular display element and the outline in the enlarged character image overlapping the rectangular display element.

The element luminance value calculating unit may calculate the luminance value for the rectangular display element based on the number of times that the outline of the enlarged character image overlapping the rectangular display element crosses the side of the rectangular display element in the longitudinal direction. The luminance value of the rectangular display element may be calculated based on the position where the outline of the enlarged character image overlapping the rectangular display element intersects the longitudinal side of each rectangular display element.

Further, a luminance value converter may be provided for converting the luminance values for each rectangular display element into luminance values corresponding to the brightness characteristics of each rectangular display element so that the N rectangular display elements have the same brightness.

A plurality of gradation character generation units may be provided, and a selection unit for selecting an arbitrary gradation character generation unit from the plurality of gradation character generation units based on font type information as the character information may be provided.

Further, the element luminance value calculating unit distributes the luminance for each coordinate corresponding to the shape of the display element on the basis of the calculated luminance value, and applies the value which caused the brightness balance of the display element to the allocation value. May be used.

On the other hand, the pixel resolution of the display unit is preferably 120 ppi (pixels per inch) ~ 240 ppi.

In addition, the display control apparatus of the present invention, in a state in which N rectangular display elements capable of displaying different colors (N is a natural number of two or more) are orthogonal to the longitudinal direction of the rectangular display element in a predetermined arrangement direction. A display unit which is formed by successively repeating a predetermined sequence in the arrangement direction, and displaying a color image by mapping N display elements arranged in a predetermined sequence in the arrangement direction to one pixel of a display target image A display control device for controlling display of a character, comprising: a multi-gradation character generation unit for generating information on a multi-gradation character image obtained by gradating a character edge based on character information on a display target character, and the display unit An element display control unit for controlling respective rectangular display elements to control the display state of the display unit; The display control unit causes each rectangular display element to correspond to one or more pixels, respectively, based on the information on the multi-gradation character image to display the multi-gradation character image.

On the other hand, the multi-gradation character generating unit uses the N rectangular display elements to store M (M is a natural number) times in the length direction and N times the size in the arrangement direction with respect to the character size of the display target character. Generating the enlarged character image information relating to the enlarged character image for display by causing one-pixel display, and based on the enlarged character image information generated by the multi-gradation character generation unit, An element that corresponds to each of the rectangular display elements for each pixel column composed of M pixels continuous in the longitudinal direction, and calculates luminance values for the one rectangular display element based on pixel values given to each of the M pixels. An image calculated by the element luminance value calculation unit by the element display control unit; Therefore, the luminance value may be controlled by a respective rectangular display device, even if the display the enlarged character image on the display unit as the character size.

Further, in the display section, the N rectangular display elements arranged in a predetermined order in the arrangement direction form a substantially square rectangular element, and the multi-gradation character generating unit is adapted to the character size of the display target character. Image information of the same character having a size of 1 times in the longitudinal direction and N times in the arrangement direction may be generated as the enlarged character image information.

Further, even if the element luminance value calculating unit calculates the luminance value for the rectangular display element based on the overlapping information between each rectangular display element and the enlarged character image in the orthogonal image coordinate system formed corresponding to the rectangular display element. The luminance value for the rectangular display element may be calculated based on the area information of the enlarged character image overlapping the rectangular display element.

The element luminance value calculation unit calculates a luminance value for the rectangular display element based on a position where an outline in the enlarged character image overlapping the rectangular display element intersects a side in the longitudinal direction of each rectangular display element. You may.

Further, a luminance value converter may be provided for converting the luminance values of the rectangular display elements into luminance values according to the brightness characteristics of each rectangular display element so that the N rectangular display elements have the same brightness.

In addition, a plurality of multi-gradation character generation units may be provided, and a selection unit for selecting an arbitrary multi-gradation character generation unit from the plurality of multi-gradation character generation units based on font type information as the character information may be provided.

In addition, the element luminance value calculating unit may distribute luminance for each coordinate corresponding to the shape of the display element, and may use the value obtained by causing the brightness balance of the display element to act on this allocation value as the luminance value of the character image.

On the other hand, it is preferable that the pixel resolution of the display unit is 120 ppi (pixels per inch) to 240 ppi.

In addition, the display method of the present invention includes the N rectangular display elements capable of displaying different colors (N is a natural number of 2 or more) in a state in which the longitudinal direction of the rectangular display element is orthogonal to a predetermined array direction. It is formed by successively repeating a predetermined sequence in the arrangement direction, wherein the N display elements arranged in the predetermined sequence in the arrangement direction correspond to one pixel constituting the display target image and display characters on the display unit. A display method for displaying a display, comprising: a multi-gradation character generation step of generating information on a multi-gradation character image in which a character edge is gradated based on character information about a character to be displayed, and each rectangular display element constituting the display portion; An element display control step of controlling to control the display state on the display unit, and in the element display control step Standing, the is based on information relating to the gray-scale character image, characterized in that the each of the rectangular display device displays all the more so as to correspond to one pixel gradation character image, respectively.

On the other hand, in the multi-gradation character generation step, the N characters of the rectangular display elements having M (M is a natural number) times in the length direction and N times the size in the arrangement direction with respect to the character size of the display target character. Generate enlarged character image information about an enlarged character image for display by causing one pixel display to be performed, and at the same time, based on the enlarged character image information generated in the multi-gradation character generation step, One rectangular display element corresponds to each pixel column consisting of M pixels consecutive in the longitudinal direction of the pixel, and calculates a luminance value for the rectangular display element based on a pixel value given to each of the M pixels. And an element luminance value calculating step, wherein the element display control step comprises: In accordance with the luminance value calculated from the value calculation step to controlling the respective rectangular display element, the expanded character image in the character size may be displayed on the display unit.

Further, in the display section, N rectangular display elements arranged in a predetermined order in the arrangement direction form a substantially square rectangular element, and in the multi-gradation character generating step, the character size of the display target character. The image information of the same character having a size of 1 times in the longitudinal direction and N times in the arrangement direction may be generated as the enlarged character image information.

In the element luminance value calculating step, the luminance value for the rectangular display element is based on the overlapping information between each rectangular display element and the enlarged character image in the rectangular image coordinate system formed corresponding to the rectangular display element. You may calculate.

In the element luminance value calculating step, the luminance value for the rectangular display element may be calculated based on the area information of the enlarged character image overlapping the rectangular display element. The luminance value for the rectangular display element may be calculated on the basis of the position where the outline in the enlarged character image overlapping the rectangular display element crosses the side of the rectangular display element in the longitudinal direction.

Further, a luminance value conversion step of converting the luminance values for each rectangular display element into luminance values according to the brightness characteristics of each rectangular display element may be provided so that the N rectangular display elements have the same brightness.

Further, a plurality of multi-gradation character generation means for realizing the multi-gradation character generation step are provided, and an arbitrary multi-gradation character generation means is selected from the plurality of multi-gradation character generation means based on font type information as the character information. An optional step may be provided.

In the element luminance value calculating step, luminance may be distributed for each coordinate corresponding to the shape of the display element, and a value obtained by causing the brightness balance of the display element to act on this allocation value may be the luminance value of the character image.

On the other hand, it is preferable that the pixel resolution of the display unit is 120 ppi (pixels per inch) to 240 ppi.

In addition, the display control program of the present invention is arranged in a state in which N rectangular display elements capable of displaying different colors (N is a natural number of 2 or more) orthogonal to the longitudinal direction of the rectangular display element in a predetermined arrangement direction. A display unit which is formed by successively repeating a predetermined sequence in the arrangement direction, wherein the N display elements arranged in the predetermined sequence in the arrangement direction correspond to one pixel of a display target image to display a color image A display control program for controlling display of characters, the display control program comprising: a multi-gradation character generation unit for generating information on a multi-gradation character image obtained by gradating a character edge based on the character information on the display target character, and the display unit The computer is a device display control unit which controls each rectangular display element that forms each other and controls the display state on the display unit. And functioning the computer to cause the element display control unit to display the multi-gradation character image by mapping each rectangular display element to one or more pixels, respectively, based on the information about the multi-gradation character image. It features.

In addition, the above-described display control program is recorded in the computer-readable recording medium of the present invention.

According to the present invention, there are the following effects or advantages.

(1) In the multi-gradation character generation unit, multi-gradation of the character edges of the character image is calculated, and the luminance value of each display element constituting the display unit is calculated on the basis of the multi-gradation character image, and the element luminance value calculation unit calculates this. By mapping to rectangular coordinates corresponding to each rectangular display element of the quantization error, the quantization error can be reduced, thereby reducing distortion of a character image displayed on a liquid crystal display such as a flat panel display, thereby improving display quality of the character. In the case of displaying high-definition characters, it is possible to display characters with high visibility with little distortion or the like.

(2) The type face of the high resolution outline font can be preserved, the deterioration of the design quality in the character image can be reduced, and the display quality (quality) can be improved. That is, the accuracy of reproduction of outline font outlines can be increased, and the jaws of the character images displayed on the display portion (the jagged shape at the edges of the characters) can be reduced, and the display image quality of the characters can be improved.

(3) The multi-gradation character generation unit generates a multi-gradation character image of size M times in the longitudinal direction and N times in the arrangement direction with respect to the character size of the character image to be displayed, and the element luminance value calculation unit generates this multi-gradation character image. For each pixel column composed of M pixels continuous in the longitudinal direction, one rectangular display element is associated with each other, and a luminance value for one rectangular display element is calculated based on a pixel value given to each of the M pixels. The display control unit controls each rectangular display element in accordance with the luminance value calculated by the element luminance value calculation unit, and causes each character constituting the character image to be displayed on the display unit at the character size, so that M pixels in one rectangular display element. Can be displayed correspondingly, and a more precise character image can be displayed on a display part.

(4) The element luminance value calculating section calculates an average value of pixel values given to each of the M pixels, and calculates a luminance value for one rectangular display element based on this average value, thereby easily calculating the luminance value of the rectangular display element. Can be.

(5) The luminance value converting unit converts the luminance value for each display element into a luminance value corresponding to the brightness characteristic of each display element so that the same brightness is obtained when the N display elements are displayed according to the same luminance value. By doing so, when the display elements are of the same luminance value, their brightness becomes constant, so that the brightness of the character image displayed on the display unit 2 is eliminated, and the image quality to be displayed is improved.

(6) An existing rasterizer can also be used, thereby increasing the versatility.

(7) Processing can be speeded up by calculating the luminance value for the rectangular display element based on the combining information between each rectangular display element and the enlarged character image in the rectangular image coordinate system formed corresponding to the rectangular display element.

(8) Since a plurality of multi-gradation character generation units can be used, a character image can be generated using the multi-gradation character generation unit corresponding to the font among these plurality of multi-gradation character generation units, thus providing high convenience.

1 and 2 show a display device according to a first embodiment of the present invention, respectively.

3 and 4 are diagrams for explaining a method of realizing character image gradation in the display device of the first embodiment of the present invention, respectively.

5A and 5B are views for explaining a coordinate conversion method in the display device of the first embodiment of the present invention.

6A and 6B are diagrams showing luminance values having the same brightness when the display elements of R, G, and B each emit light according to the same luminance value.

Fig. 7 is a diagram showing an example of brightness constant gradations in the display device of the first embodiment of the present invention.

8A, 8B, 8C, 8D, 8E, and 8F are views for explaining processing of the calculation means (display control unit) in the display device of the first embodiment of the present invention.

Fig. 9 is a diagram showing a flow for explaining a display method of a character image in the display device of the first embodiment of the present invention.

10A, 10B, 10C, 10D, 10E, and 10F are views for explaining processing of the calculation means (display control unit) in the display device of the second embodiment of the present invention.

11A, 11B, 11C, 11D, 11E, and 11F are views for explaining processing of the calculation means (display control unit) in the display device of the third embodiment of the present invention.

Fig. 12 is a diagram showing a flow for explaining a display method of a character image in the display device of the third embodiment of the present invention.

Fig. 13 is a block diagram showing a hardware configuration of a display device of a fourth embodiment of the present invention.

Fig. 14 is an example of a correspondence table between a font and a rasterizer used in the display device as the fourth embodiment of the present invention.

15 is an example of an application range of the display device of each embodiment of the present invention.

16 is a diagram illustrating a relationship between contrast sensitivity and spatial frequency.

17A, 17B, and 18 are diagrams for explaining another luminance distribution (weight calculation) method in the display device as the third embodiment of the present invention, respectively.

19A, 19B, 20A, and 20B are diagrams for explaining distortion of characters in the conventional character image display method, respectively.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(A) Description of the first embodiment

1 and 2 show a display device as a first embodiment of the present invention, FIG. 1 is a block diagram showing a functional configuration thereof, and FIG. 2 is a block diagram showing a hardware configuration of the display device of this first embodiment. to be.

The display device 1a of the first embodiment is provided in an information processing device such as a computer, for example. As shown in FIG. 1, the display device 2a and the display control part 3a are provided.

The display part 2 displays the character image etc. which are display objects, for example, is implement | achieved by a color liquid crystal display. As shown in Fig. 1, the display unit 2 has three types of N types (R (Red; Red), G (Green; Green), and B (Blue; Blue) in the present embodiment, that is, N = 3). Is configured to include a plurality of rectangular display elements 10, and a color originally configured to represent one pixel by the rectangular display elements 10 of these N types (three colors of R, G, and B in this embodiment). Image display is possible.

As shown in FIG. 1, the display unit 2 has a longitudinal direction (up and down direction in FIG. 1; hereinafter referred to as a longitudinal direction) of each rectangular display element 10 in a predetermined arrangement direction (left and right direction in FIG. 1). R, G, B, R, G, B... It is arranged regularly in the order of.

Hereinafter, as a set of three rectangular display elements 10 adjacent to each other, R, G, and B, a collection of N rectangular display elements 10 used in cooperation with one pixel is referred to as a basic display element set 101. . In addition, below, the rectangular display element 10 may only be called the display element 10 in some cases.

In addition, in the display device 1a of the first embodiment, each display element 10 is configured such that the dimension ratio in the longitudinal direction and the arrangement direction is N: 1 (3: 1 in the present embodiment), and R, G When the three display elements 10 of B are arranged side by side in the arrangement direction, these three display elements 10, that is, the basic display element set 101 have an almost square shape.

And in the display part 2, the rectangular display elements 10 of the same kind (color) are arrange | positioned (in series) in the longitudinal direction of the rectangular display element 10, respectively.

That is, the display part 2 is comprised by repeatedly arranging the basic display element set 101 in a vertical direction and a horizontal direction, respectively, In the display part 2, N type (N = 3 in this embodiment) is rectangular. In the state in which the display element 10 orthogonally crosses the longitudinal direction (for example, the up and down direction in FIG. 1) in a predetermined array direction (for example, the left and right direction in FIG. 1), the predetermined order (in FIG. 1) in the array direction. In the illustrated example, it can be said that they are repeatedly arranged in succession (in the order of R, G, and B).

In addition, in this invention, the display form and structure of the display part 2 are not specifically limited, For example, N type display elements 10 which comprise the display part 2 in the range which does not deviate from the meaning of this invention. Can be implemented by various modifications to the arrangement order, the display method of the display unit 2 as described above, the control method thereof, and the like.

The display control unit 3a performs control for displaying a character image on the display unit 2 described above. As shown in FIG. 1, the multi-gradation character generating unit 4a, the element luminance value calculating unit 5, and The element display control part 6 is provided and comprised.

The multi-gradation character generation unit 4a generates information on the multi-gradation character image obtained by gradating the character edges based on the character information on the character to be displayed.

Here, the character information is composed of font information which is information for forming a character image (glyph) in addition to text data (character code) that is information for specifying the character content as various information about the character. . On the other hand, the font information includes the type of font (e.g., Gothic, Ming, etc.), the font modifier data (e.g., bold or not, long and decorative lines (serif), size information), and the like.

In addition, the multi-gradation character generation unit 4a uses the multi-gradation character image (based on the outline font formed by using the reproduction data (hereinafter referred to as outline data) of individual curves constituting the character outline as font information). Information about a multi-valued text image).

The outline data is composed of curve data constituting the closed curve of the character image. For example, when a Bezier curve shown in the following equation is used as the curve data, the font memory 13a has x1 and x2. The coordinate values of, x3, x4, y1, y2, y3, y4 are stored as outline data.

x = (1-t) ³ * x ₁ + 3 * (1-t) ² t * x ₂ +3 (1-t) * t ² * x ₃ + t ³ * x ₄

y = (1-t) ³ * y ₁ + 3 * (1-t) ² t * y ₂ +3 (1-t) * t ² * y ₃ + t ³ * y ₄

(Where 0≤t≤1)

In addition, the font formed using the outline data is called an outline font, and in this specification, it is distinguished from the stroke font formed using the reproduction data of the individual curve which comprises a character center line.

The multi-gradation character generation unit 4a is "information about a multi-gradation character image", and may be actually created (outputted) using the multi-gradation character image itself as a product, and for specifying a multi-gradation character image. Only the information may be generated (outputted). In the present embodiment, both of these embodiments are referred to as "generation of information on a multi-gradation character image". In the following description, the multi-gradation character generation unit 4a is described. The case of generating a multi-gradation character image itself will be described.

The multi-gradation character generation unit 4a forms a character image (multi-gradation character image) obtained by multi-grading the outline (edge) portion based on the outline data described above. Specifically, the multi-gradation character generation unit 4a generates a character image by calculating the character outline based on the outline data, and then performs a process of painting (rasterizing) all of the inside of the outline, and generating the character image. By performing an antialiasing process for smoothly showing the jagged shape of the curved edge constituting the character with respect to one character image, a multi-gradation character image (multi-gradation character image information) is formed.

On the other hand, as a method of multi-gradation (anti-aliasing) a character image, it can implement | achieve using existing various methods, The example is mentioned later.

The element luminance value calculating unit 5 is configured to display elements 10 constituting the display unit 2 such that the multi-gradation character image generated by the multi-gradation character generation unit 4a is displayed on the display unit 2. By calculating the luminance values for the pixels, each pixel constituting the multi gradation character image (pixel unit coordinate system) generated by the multi gradation character generation unit 4a is transferred to the plurality of display elements 10 constituting the display unit 2. The luminance value for each display element 10 is calculated by mapping (coordinate transformation) to a corresponding rectangular pixel coordinate system (display element coordinate system).

Specifically, the element luminance value calculation unit 5 associates one display element 10 for each pixel column composed of M pixels continuous in the longitudinal direction included in the multi-tone character image, and these M pixels. Luminance values for one rectangular display element 10 are calculated based on the pixel values given to each of.

In the present embodiment, the luminance value is a numerical value (for example, 0 to 255) indicating brightness, and is used to control the light emission (transmission) state of each display element 10. It contains instructions for control.

The element display control unit 6 controls the display state of the display unit 2 by controlling each display element 10 of the display unit 2, and is based on the luminance value calculated by the element luminance value calculator 5. Thus, control is made to display the multi-gradation character image on the display unit 2. For example, the element display control unit 6 controls the display state of the character image by controlling the drive voltage of the display unit 2 and the like.

In addition, the display control unit 3a associates each display element 10 with one or more pixels (three pixels in the first embodiment), so that N pieces (N types; N = 3 in this embodiment) are contiguous. The display element 10 (basic display element set 101) can display a plurality of pixels (9 pixels in this embodiment).

In the display device 1a of the first embodiment, the display control unit 3a includes M rectangular display elements 10 that are continuous in a direction (length direction) orthogonal to the array direction (M = in this embodiment). Corresponding to the pixel of 3), the N rectangular display elements 10 (basic display element set 101) cause the matrix type pixel group of M x N (3 x 3 in the first embodiment) to be displayed. It is.

A more specific configuration of the display device 1a of the first embodiment is shown in FIG. As shown in FIG. 2, the display apparatus 1a is equipped with the character input means 11, the calculation means 12, the memory | storage device 13, and the display part 2. As shown in FIG.

The character input means 11 inputs the information (character information) for specifying the character to display on the display part 2, for example, is comprised by the document file 11a which stored the character information, the keyboard 11b, etc. do. The character input means 11 is realized by an API (Application Program Interface) of an application such as a content viewer, in addition to various devices having input functions such as a keyboard, a mouse, a floppy disk drive, and the like of a computer system.

The storage device 13 includes a font memory 13a and an image memory 13b. The font memory 13a stores information for forming multi-gradation character images and character images, and corresponds to various storage devices such as a hard disk and a memory in a computer system.

In this embodiment, the font memory 13a includes font size (character image size; for example, 5 points, etc.) and font type (for example, Ming, Gothic, etc.) as font information (font data) for forming a multi-value gradation character image. ), Outline data corresponding to various conditions (font information) such as font modification data (for example, bold text, long body, etc.), and the presence or absence of font modifications are stored.

The image memory 13b temporarily stores a luminance value for displaying a character image on the display unit 2, which is created based on the multi-gradation character image generated by the multi-gradation character generation unit 4a (character image generation unit 12b). This is equivalent to memory in a computer system.

The display unit 2 is configured to display a character image developed (stored) in the image memory 13b, and is controlled by the calculation means 12.

The calculation means 12 performs various calculations and corresponds to a CPU (Central Processing Unit) in a computer system. In addition, as shown in Fig. 2, the calculation means 12 includes a font selection unit 12a, a character image generation unit 12b, an anti-aliasing processing unit 12c, and a subpixel gradation processing unit 12d. This corresponds to the display control section 3a described above.

The font selection unit 12a acquires the character size information for the characters instructed by the character input unit 11 to display on the display unit 2 based on the character information (text data and font information). The outline data concerning the character is acquired from the font memory 13a.

Based on the outline data acquired by the font selection unit 12a, the character image generation unit 12b enters a normal display mode of size M times in the length direction and N times in the arrangement direction with respect to the input character size. An enlarged character image (hereinafter referred to as a multi-valued character image) for display is formed. On the other hand, in the present embodiment, the case where M = N = 3 will be described.

On the other hand, the normal display mode refers to a display mode in which the display unit 2 causes one pixel to be displayed by the N display elements 10 (the basic display element set 101). In the present display device 1a, Character image information used when displaying one pixel by the three rectangular display elements 10 of R, G, and B may be referred to as normal character image information.

The calculation means 12 acquires the outline data of the character image to be displayed from the font memory 13a based on the character information input from the character input means 11, and based on these outline data and the character information, An enlarged character for displaying, in the normal display mode, the same character of size M times in the longitudinal direction and N times in the arrangement direction with respect to the character indicated by the character input means 11 to display. An image (hereinafter referred to as a character image) is formed.

Then, in the display device 1a of the first embodiment, the character image generation unit 12b (calculation means 12) uses the input character size (based on the outline data acquired by the font selection unit 12a). For example, an enlarged character image of the same character of three times size (N = M = 3; for example, 5 × 3 = 15 points) is created in the longitudinal direction and the arrangement direction, respectively.

The anti-aliasing processing section 12c generates an gradated text image (multi-gradation text image) by performing gradation with anti-aliasing processing on the text image (binary) created by the text image generation section 12b.

3 and 4 are diagrams for explaining a method for realizing the gradation of a character image in the display device 1a as the first embodiment of the present invention, respectively, and FIG. 3 is a diagram for explaining the area gradation method. to be. 4 is a view for explaining a method for creating a multi-gradation character image (gray scale font) using a smoothing filter. Part of the character image, an example of a smoothing filter used for creating a gradation character image, and the created multi-gradation character image. A part of each is enlarged and shown.

As shown in Fig. 3, gradation using the area gradation method forms a character image (character outline, outline) formed on the basis of outline data on a matrix having a predetermined size scale formed in correspondence to the pixels. It expands so that it may overlap each other, and is performed by determining the pixel value of the pixel corresponding to each scale according to the ratio of the area which a character image (character outline) overlaps in each scale. In the example shown in FIG. 3, the pixel value of each pixel is represented by 256 gray scales of 0 to 255, and the pixel value of the pixel (100% overlapping rate) superimposed completely on the character image is 0 (black). The pixel value of the pixel that does not overlap at all (0% overlap) is set to 255, and the pixel value of the partially overlapped pixel is set in proportion to the overlapping area.

In the gradation method using the smoothing filter, as shown in Fig. 4, a smoothing filter (e.g., 1/16 1/8 1/16) constituted by a matrix of 3x3 for a character image composed of two gray levels. , 1/8 1/4 1/8, 1/16 1/8 1/16), a multi-gradation character image (gradation font, gray scale font) can be formed. In addition, the smoothing filter to be used is not limited to that shown in Fig. 4 but can be modified in various ways.

In the display device 1a of the first embodiment, the anti-aliasing processing unit 12c performs multi-gradation of a character image using, for example, the area gray scale method described above.

That is, in the display device 1a of the first embodiment, the above-described character image generation unit 12b and the anti-aliasing processing unit 12c generate a multi-value character image for display on the display unit 2, and the character The multi-value character image (based on the outline data acquired from the font memory 13a by the font selection unit 12a with respect to the character whose display on the display unit 2 is instructed and inputted by the input unit 11). Character image subjected to anti-aliasing processing). Therefore, in the display device 1a of the first embodiment, the character image generation unit 12b and the anti-aliasing processing unit 12c function as rasterizers having an anti-aliasing function.

The subpixel gradation processing unit 12d is a process for expanding the multi-value character image created by the character image generation unit 12b and the anti-aliasing processing unit 12c to the rectangular display elements 10 constituting the display unit 2. To do.

This subpixel gradation processing unit 12d coordinates the coordinates (pixel unit coordinates; see FIG. 5A) of each pixel constituting the multi-value character image with coordinates corresponding to the rectangular display elements 10 constituting the display unit 2. (Orthogonal element coordinates; see FIG. 5B).

Then, the subpixel gradation processing unit 12d develops the mapped-converted multi-value character image into, for example, the image memory (display memory) 13b and is included in the multi-value character image developed in this image memory 13b. Pixel values given to each of these three pixels by corresponding one display element 10 for each pixel column consisting of three pixels that are continuous in the longitudinal direction (the direction orthogonal to the arrangement direction of the display element 10). The luminance value of each display element (rectangular display element) 10 is calculated on the basis of the above, and accordingly, the three display elements 10 (basic display element set 101) adjacent to each other in the array direction are 3 ×. The matrix pixel group of 3 is displayed so that the display portion 2 displays a character image as a display object.

Here, a control method for causing the subpixel gradation processing unit 12d to display the character image to be displayed on the display unit 2 will be described with reference to the drawings. 5A and 5B are diagrams for explaining a coordinate conversion method in the display device of the first embodiment of the present invention, respectively, and Fig. 5A shows an example of coordinates (pixel unit coordinates) of each pixel constituting a character image. 5B is a diagram illustrating an example of display coordinates (orthogonal element coordinates) of each display element 10.

The subpixel gradation processing unit 12d first performs a direction perpendicular to the arrangement direction of the display elements 10 of R, G, and B, that is, the display element 10, with respect to the pixels constituting the multi-value character image. The luminance value of each corresponding display element 10 is calculated on the basis of these adjacent three pixel values for each pixel column consisting of three pixels continuous in the longitudinal direction.

In the first embodiment, the subpixel gradation processing unit 12d calculates the luminance value of the display element 10 on the basis of pixel values for each pixel column composed of three pixels continuous in the longitudinal direction, Coordinate transformation is performed from the pixel coordinate system to the Cartesian element coordinate system.

On the other hand, in the first embodiment, the subpixel gradation processing unit 12d is a method for calculating the luminance value of the display element 10, based on pixel values for each pixel column composed of three consecutive pixels. The pixel values of the three pixels are averaged and calculated.

For example, in FIG. 5A, the pixel value of the pixel located at coordinate (m, n-1) in pixel unit coordinates is Pmn-1, and the pixel value of the pixel located at coordinate (m, n) is Pmn and coordinate (m, n). When the pixel value of the pixel located at +1) is expressed as Pmn + 1, the average value P 'of these three pixels is calculated by the following equation (1).

P ’= (Pmn-1 + Pmn + Pmn + 1) / 3 (1)

On the other hand, when the average value P 'of three pixels represents the average value of three pixels corresponding to the display element 10 of R (Red; red), the sign P' is added as the sign P ' _R by adding the sign "R" to the sign P'. Indicates. In the same manner, the average value of the three pixels corresponding to the display element 10 of G (Green) is the average value of the three pixels corresponding to the display element 10 of the symbols P ' _G and B (Blue). It is assumed to be represented using the symbols P ' _B , respectively.

The subpixel gradation processing unit 12d corresponds to the display element 10 (see FIG. 5B) for each of the calculated average pixel values (see FIG. 5A) for each of the three pixels, thereby calculating the average value P ′ for the three pixels. ) Is converted into the coordinates (orthogonal element coordinates) of one display element 10.

In addition, the coordinate (pixel unit coordinate) in the coordinate system (pixel unit coordinate system) shown by the coordinate (m, n) shown in FIG. 5A hereafter is represented by the coordinate (u, v) shown in FIG. 5B. The process of converting into a coordinate (orthogonal element coordinate) in the losing coordinate system (orthogonal element coordinate system) may be referred to as a coordinate transformation operation.

For example, in the example shown in Figs. 5A and 5B, three pixels located at coordinates (m, n-1), (m, n) and (m, n + 1) are positioned at (u, v). It displays using G display element 10.

For example, the luminance value Q _G of the display element 10 of G located at the coordinates (u, v) in the rectangular coordinate system is represented by the following equation (2).

Q _G (u, v) = F _G (P ' _G ) (2)

only,

u = m

v = int [(n + 2) / 3]

to be. On the other hand, it is assumed that the expression int [a] represents the integer part of the numerical value a surrounded by "[" and "]". F is a function for converting luminance values, for example, represented by a linear function such as F (x) = αx + β. Here, β denotes an offset and α denotes an amplification factor, respectively.

Regarding the display element 10 of R and the display element 10 of B in the same manner, the luminance values are calculated by the following equations (3) and (4), respectively.

Q _R (u, v) = F _R (P ' _R ) (3)

Q _B (u, v) = F _B (P ' _B ) (4)

5A and 5B, three pixels respectively positioned at coordinates (m, n-1), (m, n) and (m, n + 1) are represented by (u, v). Although the example which displays using G display element 10 located in () is shown, it is not limited to this.

For example, three pixels located at coordinates (m, n-2), (m, n-1) and (m, n) are displayed using the display element 10 of G located at (u, v), or , Three pixels located at coordinates (m, n), (m, n + 1) and (m, n + 2) are displayed using the display element 10 of G located at (u, v) These pixels may be displayed using the display element 10 of R located at (u-1, v) or the display element 10 of B located at (u + 1, v), Various modifications can be made without departing from the spirit of the invention.

In addition, in the display device 1a of the first embodiment, the subpixel gradation processing unit 12d (element luminance value calculating unit 5) has a function as the luminance value converting unit 7, and the luminance value (Q _R , Q _G , Q _B ) is calculated, and a conversion process is performed in which the brightness levels of the display elements 10 of R, G, and B are the same for these luminance values.

The luminance value converting unit 7 converts the luminance values developed on the display elements 10 of R, G, and B into grayscales having constant brightness according to the color of each display element 10. When the three display elements 10 of B have the same luminance value (in the same gradation), the luminance value for each display element 10 is converted into the luminance value according to the brightness characteristic of each display element 10 so as to have the same brightness. The conversion process is performed.

Here, the conversion processing by the luminance value conversion section 7 will be described with reference to the drawings.

The luminance value converting unit (the subpixel gradation processing unit 12d) displays each of R, G, and B based on the calculation result of the luminance values Q _R , Q _G , and Q _B for the display element 10. When the elements 10 have the same luminance values, the calculated luminance values are subjected to the process shown in the following equation so that the light emission of each display element 10 has the same brightness.

When the luminance values calculated from the pixel values of the character image are Q _R , Q _G, and Q _B , respectively, they are equivalent to these Q _R , Q _G, and Q _B, and only the display positions of the liquid crystal display (the display portion 2) When R ', G', and B 'are used as codes indicating whether they are in the R position, G position, and B position, respectively, the luminance values R'brightness, G converted to a constant gray scale (hereinafter referred to as brightness gray scale) 'brightness and B'brightness can be calculated by the following equations (5) to (7).

R'brightness = Fb (0.60R ') (5)

G‘brightness = Fb (0.384G ’) (6)

B'brightness = Fb (1.0B ') (7)

On the other hand, Fb is a function for constant gradation, for example, represented by a linear function such as Fb (x) = α 'x + β'. Here, β 'is an offset value and is set so that the brightness of each display element of R, G, and B is constant. Α 'is represented by the following equation (8).

α '= ((total number of gradations of brightness gradation)-(offset value)) / (total number of luminance indications) (8)

By the way, the brightness value after the conversion is L, Y is the Y stimulus value of the XYZ front color system, Y is the standard light source used by the illumination or the three stimulus values of the standard light, Y0, each on the display monitor (display device 2). If the gray scale value (stimulus value; corresponding to 0 to 255, for example) is R ', G', or B ', the following relational expressions (9) to (14) hold.

L * = 116 (Y / Y0) ^1/3 -16 (9)

Y = aR + bG + cB (10)

Y0 = 1. 0 (11)

R = (d (R '+ e)) ^{2. 4} (12)

G = (d (G '+ e)) ^{2. 4} (13)

B = (d (B '+ e)) ^{2. 4} (14)

On the other hand, a to e are constants. In addition, R, G, and B are color coordinates in an RGB front color system, and have no units, and are converted to the XYZ color gamut by constant conversion. L * is the brightness, and in the case of light emission, it represents the luminance ratio. X, Y and Z are also one of the color systems and have no units.

Now, based on sRGB (International Standard IEC61966-2-1),

a: b: c = 0.2126: 0.7152: 0.0722

R ': G': B '= 0.60: 0.384: 1.00 (15)

When the brightness is made constant, for the range of B, the luminance of G and R corresponds to using the ranges of 0.6 and 0.384, respectively.

And when a luminance value is constant (R '= G' = B '), following formula (16) is calculated | required.

R‘brightness: G’brightness: B’brightness = 0.600: 0.384: 1.00 (16)

On the other hand, the above-described ratio of R'brightness: G'brightness: B'brightness allows an error of about 100. therefore,

R‘brightness: G’brightness: B’brightness

= (0.600 ± 0.100) :( 0.384 ± 0.100) :( 1.00 ± 0.100) (17)

You can do

That is, in the display device 1a of the first embodiment, the luminance value converting unit 7 converts the luminance values of the three display elements 10, that is, the R element, the G element, and the B element. The above conversion process is performed such that the ratio of the subsequent luminance values is (0.600 ± 0.100) :( 0.384 ± 0.100) :( 1.000 ± 0.100) so that the same brightness is achieved when the R, G, and B elements have the same luminance.

On the other hand, according to equations (9) and (11), only Y is a coordinate indicating brightness in the XYZ color system. If e is sufficiently small, a, b, c, and R ', G', and B 'are almost equal to 1 / 2.4 times the inverse, thereby deriving the above equation (15).

FIG. 6A is a diagram showing luminance values R'brightness, G'brightness, and B'brightness when the display elements 10 of R, G, and B emit light according to the same luminance value. A diagram showing an example in which the total number of gray scales is 256 (0 to 255), and FIG. 6B is a case in which (R, G, B) = (6, 4, 10) is set as an offset value in FIG. 6A. It is a drawing of.

For example, referring to FIG. 6A, when the luminance values of the display elements 10 of R, G, and B calculated by the element luminance value calculating unit 5 are each 100 and are the same luminance ((R ', G ', B') = (100, 100, 100)), in order to make the brightness of each of the display elements 10 of these R, G, and B constant, (R'brightness, G'brightness, B'brightness) Display control of each display element 10 is performed using the luminance value converted into = (60, 38, 100).

FIG. 7 is a diagram showing an example of the constant brightness of the brightness in the display device 1a according to the first embodiment of the present invention, which is based on the gradation value 0 and when the brightness is 6 gradations. And B show luminances with matching brightness in each color. In FIG. 7, brightness of each color of R, G, and B coincides in the luminance value aligned in the vertical direction. That is, the brightness of each display element 10 of R, G, B is proportional to the gradation level, and the brightness value of each of the display elements 10 of R, G, B in the same gradation is constant.

The brightness change with respect to the luminance of RGB has the widest range of green (G), and the narrowest range of blue (B). Therefore, in the case of performing gradation based on lightness, it is necessary to match the range of two colors different to the change in blue with the narrowest lightness change range. Here, when the number of gray levels of blue is set to 256 (0 to 255), the number of gray levels of green can be set to a natural number not exceeding (256 x 0.384 / 1.00).

As described above, the subpixel gradation processing unit 12d (element luminance value calculating unit 5) calculates the luminance value for each display element 10, and calculates the calculation means 12 in accordance with the calculated luminance value. (The display control part 3a) controls each display element 10, and the character which comprises a character image is displayed on the display part 2. As shown in FIG.

On the other hand, according to the luminance value (gradation value; for example, 0 to 255) obtained corresponding to each display element 10, a method of causing the display unit 2 to display by controlling the light emission state of each display element 10 It can be realized using a variety of existing methods, the description thereof will be omitted.

Processing of the calculation means 12 (display control section 3a) in the display device 1a according to the first embodiment of the present invention configured as described above is shown in FIGS. 8B, 8C, 8D, 8E, and 8F. With reference to FIG. 8A, it demonstrates according to the flowchart shown in FIG. 8A (steps A10-A100).

When the character code specifying the character to be displayed is input by the character input means 11 (step A10), on the basis of the input character information (font information, character code) (see Fig. 8B), the font selector 12a Information (outline data) relating to the outline font for the character to be displayed is obtained (character coded) from the font memory 13a (step A20).

On the other hand, in the example shown in Fig. 8B, font size: 5 points, font type: Gothic and serif; The example in which the font information which consists of none and the information which consists of the character code (0x83 bf) which shows the character "(alpha)" were input as character information is shown.

Then, the font selection unit 12a obtains three times the size (for example, 15 points) in the longitudinal direction and the arrangement direction, respectively, for the character size (for example, 5 points) of the character image to be displayed (size conversion; step A30). The character image generation unit 12b forms a character image of the same character of this calculated size (rasterize; see step A40, FIG. 8C), and the anti-aliasing processing unit 12c calculates the boundary of this character image. Harmonization (anti-aliasing; step A50) is performed to generate a multi-gradation character image and develop it in the image memory 13b (see Fig. 8D).

On the other hand, in the display device 1a of the first embodiment, the steps A10 to A50 may be referred to as a character generation process.

Subsequently, the subpixel gradation processing unit 12d (element luminance value calculating unit 5) is connected to the longitudinal direction of the display element 10 with respect to the multi-value character image developed in the image memory 13b. The display luminance (luminance value) is averaged (normalized) for each pixel column composed of two pixels (step A60). The subpixel gradation processing unit 12d converts the pixels of the multi-gradation character image from pixel unit coordinates to Cartesian element coordinates (step A70, see Fig. 8E).

In addition, the luminance value converting unit 7 emits light at the same luminance value of each of the display elements 10 of R, G, and B based on the luminance value calculated by the subpixel gradation processing unit 12d in step A60. Brightness gradation (brightness conversion) to be the same brightness is performed (step A80).

On the other hand, in the display device 1a of the first embodiment, the above-described steps A60 to A80 may be referred to as a subpixel gradation process.

Subpixel gradation processor 12d then expands the calculated (converted) luminance value to multi-gradation memory (image memory 13b) (see steps A90 and 8F), and calculates 12 (display control unit 3a). )) Controls the light emission state of each display element 10 according to the luminance value (character image) developed in the image memory 13b, and displays each character constituting the character image on the display unit 2 (step A100).

FIG. 9 is a diagram showing a flow for explaining a display method of a character image in the display device 1a according to the first embodiment of the present invention (steps B10 to B40), and the letter “이” is displayed on the display unit 2. An example of displaying is shown. As shown in FIG. 9, in the display apparatus 1a of this 1st Example, the information about the character image to display is acquired (step B10), and the outline information (outline) is acquired and calculated (step B20). ), A multi-gradation character image obtained by gradation of character edges is formed (step B30).

Based on the formed multi-tone character image (pixel unit coordinates), mapping conversion (mapping) is performed to orthogonal element coordinates corresponding to the rectangular display elements 10 constituting the display unit 2 (step B40). The image is displayed on the display unit 2.

As described above, according to the display device 1a as the first embodiment of the present invention, the multi-gradation character generation unit 4a (anti-aliasing processing unit 12c) multi-gradates the character edges of the character image, Based on the character image, the luminance values of the display elements 10 constituting the display unit 2 are calculated, and the element luminance value calculation unit 5 (the subpixel gradation processing unit 12d) performs this operation on the display unit 2. Since it maps to the Cartesian element coordinates corresponding to each display element (subpixel) 10, the quantization error can be made small, for example, the distortion of the character image displayed on a liquid crystal display such as a flat panel display can be reduced. It is possible to improve the display quality of the display, and to display high-definition characters with good visibility with little distortion or the like.

In addition, the type face of the high resolution outline font can be preserved, so that deterioration of the design quality in the character image can be reduced, and the display quality (quality) can be improved. In other words, it is possible to increase the outline reproduction accuracy of outline fonts, reduce the jaggedness (jagged shapes at the edges of characters) in the character image displayed on the display unit 2, and improve the character display image quality. .

Further, the multi-gradation character generation unit 4a (character image generation unit 12b) calculates the gray level value of the pixel based on the character outline and the area partitioned by each rectangular pixel, that is, the character using the area gray scale method. By multi-gradation of the image, it is possible to save the character generation precision from the outline font at the resolution of the display unit 2.

In addition, the display control unit 3a associates each display element 10 with three pixels, respectively, and displays the 3 × 3 pixel display by the three display elements 10 (the basic display element set 101). Therefore, the display for a plurality of pixels can be performed by the basic display element set 101, and a more precise character image can be displayed on the display unit 2. FIG.

Furthermore, the multi-gradation character generation unit 4a (character image generation unit 12b) generates a multi-gradation character image three times in the length direction and three times in the arrangement direction with respect to the character size of the character image to be displayed. Then, the element luminance value calculating unit (the subpixel gradation processing unit 12d) includes one rectangular display element 10 for each pixel column composed of three pixels continuous in the longitudinal direction included in this multi-gradation character image. Are associated with each other, the luminance values for one rectangular display element 10 are calculated based on the pixel values given to each of the three pixels, and the display control unit 3a is calculated by the element luminance value calculation unit 5. Each rectangular display element 10 is controlled in accordance with the luminance value so that each character constituting the character image is displayed on the display unit 2 in a character size, so that one rectangular display element 10 corresponds to three pixels. You can do this In addition, a more precise character image can be displayed on the display unit 2.

In addition, the element luminance value calculating section 5 calculates an average value of pixel values given to each of the three pixels, and calculates a luminance value for one rectangular display element 10 based on this average value, thereby easily displaying a rectangular display. The luminance value of the element 10 can be calculated.

In addition, the luminance value converting unit 7 displays the luminance values for each display element 10 so that the same brightness is obtained when the three display elements 10 display the same luminance values. By performing a conversion process of converting the luminance value according to the brightness characteristic of the display element 10 to the same brightness value, since the brightness becomes constant, the brightness is uneven in the character image displayed on the display section 2. Is eliminated, and the displayed image quality is improved.

In addition, in the basic display element set 101, a 3x3 matrix pixel group is displayed so that a 3x3 square lattice is formed to ensure isotropy in a more detailed region of the filter operation effect. Can be. Accordingly, it is not necessary to consider lattice anisotropy, and the filter design becomes easy. Moreover, the influence range of a filter can be made smaller than before. Specifically, the influence range that was three times the long axis of the current rectangular pixel is three times the short axis direction.

In addition, an existing rasterizer can also be used, thereby increasing the versatility.

(B) Description of Second Embodiment

The display device 1b as the second embodiment of the present invention is also provided in an information processing device such as a computer, for example, similarly to the display device 1a of the first embodiment, and as shown in FIG. And the display control part 3b.

The display control unit 3b performs control for displaying a character image on the display unit 2, similarly to the display control unit 3a of the first embodiment. As shown in FIG. 1, the multi-gradation character generation unit 4a Instead, it is configured in almost the same manner as the display control section 3a of the first embodiment except that the multi-gradation character generation section 4b is provided.

In addition, since the code | symbol same as the code | symbol mentioned above already shows the same or almost the same part in the figure, the description is abbreviate | omitted. In addition, since the display device 1b of the second embodiment has the same hardware configuration as that of the display device 1a shown in FIG. 2, the description of the hardware configuration will be described with reference to FIG. do.

Similar to the multi-gradation character generation unit 4a of the first embodiment, the multi-gradation character generation unit 4b also forms a character image (multi-gradation character image) in which the outline (edge) portion is multi-graded based on the outline data. After calculating the character outlines based on the outline data stored in the font memory 13a (see FIG. 2), a character image is generated by rasterizing the entire outline, and the character images are generated. An antialiasing process is performed for a single character image to make the jagged shape of the curved edges forming the character smoothly, thereby forming a multi-gradation character image (multi-gradation character image information).

Also in the display device 1b of the second embodiment, the character image generation unit 12b (see FIG. 2) has a length with respect to the input character size based on the outline data acquired by the font selection unit 12a. Direction to form an enlarged character image (hereinafter referred to as a multi-value character image) for displaying in the normal display mode of M times in the direction and N times in the arrangement direction. In the second embodiment, the character image generation unit ( 12b) forms an enlarged character image (hereinafter referred to as a multi-value character image) for displaying in the normal display mode of the size 1 time in the longitudinal direction and 3 times in the arrangement direction (that is, M = 1, N = 3). It is supposed to be.

Therefore, in the display device 1b of the second embodiment, the character image generation unit 12b is based on the outline data acquired by the font selection unit 12a, and the input character size (for example, five points). On the other hand, the enlarged character image of the same character of 3 times size (for example, 5x3 = 15 points) is produced only in the said arrangement direction.

That is, the calculation means 12 acquires the outline data of the character image to be displayed from the font memory 13a on the basis of the character information input from the character input means 11, and applies these outline data and the character information to the outline data. On the basis of this, for the character instructed to be displayed by the character input means 11, the same character of size 1 times in the longitudinal direction and N times in the arrangement direction is returned to the normal display mode with respect to the character size in the character image. An enlarged character image (hereinafter referred to as a character image) for display is formed.

Then, in the display device 1b of the second embodiment, the anti-aliasing processing unit 12c performs gradation by performing anti-aliasing processing on the character image created by the character image generation unit 12b to produce a multi-gradation character image. Then, the subpixel gradation processing unit 12d performs processing for developing the generated multi-value character image on each rectangular display element 10 constituting the display unit 2.

On the other hand, in the display device 1b of the second embodiment, the subpixel gradation processing unit 12d (element luminance value calculating unit 5) includes coordinates (pixel unit coordinates) of each pixel constituting the multi-value character image; 5A) is mapped to the multi-value character image developed in the image memory 13b when mapping to coordinates (orthogonal element coordinates; see FIG. 5B) corresponding to each rectangular display element 10 constituting the display unit 2. Each pixel in the longitudinal direction (the direction orthogonal to the arrangement direction of the display element 10) included is made to correspond to one display element 10, respectively.

Accordingly, the subpixel gradation processing unit 12d associates one pixel with one display element 10 so as to display the character image that is the display target on the display unit 2.

The process of the calculation means 12 (display control part 3b) in the display apparatus 1b as 2nd Example of this invention is shown, referring FIG. 10B, 10C, 10D, 10E, 10F. A description will be given according to the flowcharts (steps A10, A20, C45, A50 to A100) shown in 10a. In addition, since the step which has the code | symbol same as the code | symbol mentioned above already shows the same or almost the same process in the figure, the detailed description is abbreviate | omitted.

Also in the example shown in Fig. 10B, font size: 5 points, font type: Gothic and serif; The example in which the font information which consists of none and the information which consists of the character code (0x83bf) which shows the character "(alpha)" was input as character information is shown.

In the display device 1b of the second embodiment, the font selector 12a obtains a size three times (for example, 15 points) only in the arrangement direction with respect to the character size (for example, 5 points) of the character image to be displayed, The character image generation part 12b forms the character image of the same character of this calculated size (rasterize; step C45, see FIG. 10C). For example, in FIG. 10C, the dimension of the longitudinal direction (vertical direction) is a, and the example of the character image whose dimension of the arrangement direction (horizontal direction) is 3a is shown.

Then, the anti-aliasing processing unit 12c performs gradation (anti-aliasing; step A50) of the edge of this character image to generate a multi-gradation character image, and develops it into the image memory 13b (see Fig. 10D).

On the other hand, in the display device 1b of the second embodiment, the above-described steps A10, A20, C45, and A50 may be referred to as a character generation process.

Hereinafter, similarly to the display device 1a of the first embodiment, the subpixel gradation processing unit 12d performs the subpixel gradation processing and the brightness conversion processing (steps A60 to A80, see FIG. 10E), and calculates (converts) One luminance value is developed in a multi-gradation memory (image memory 13b) (steps A90 and FIG. 10F), and the calculation means 12 (display control unit 3) expands the luminance value (developed in image memory 13b). The light emission state of each display element 10 is controlled according to the character image), and each character constituting the character image is displayed on the display portion 2 (step A100).

As described above, according to the display device 1b according to the second embodiment of the present invention, the same operation and effect as the display device 1a of the first embodiment can be obtained, and the display control unit 3b has each display element 10. ) Corresponds to one pixel, so that the subpixel gradation processing unit 12d calculates the luminance value of the display element 10 based on the plurality of pixels (see equation (1) in the first embodiment). There is no need to perform such processing, and the processing time for displaying the character image can be shortened.

(C) Description of the third embodiment

The display device 1c as the third embodiment of the present invention is also provided in an information processing device such as a computer, for example, similarly to the display device 1a of the first embodiment, and as shown in FIG. And the display control part 3c.

The display control unit 3c performs control for displaying a character image on the display unit 2, similarly to the display control unit 3a of the first embodiment, and the multi-gradation character generation unit 4a and the element luminance value of the first embodiment. The functions of the calculator 5 and the brightness value converting unit 7 are integrally performed. In the calculating means 12, the character image generating unit 12b, the anti-aliasing processing unit 12c, and the subpixel gradation are performed. The function of the processor 12d is integrally performed.

In addition, in the display device 1c of the third embodiment, the calculation means 12 calculates outline information (contour coordinates) of the characters based on the outline data, and directly expands the calculated outline coordinates in the Cartesian element coordinates. (Mapping) (see FIG. 11D). On the other hand, in the display device 1c of the third embodiment, the orthogonal element coordinates that expand the outline coordinates are orthogonal to the longitudinal direction and the longitudinal direction of the unit rectangle corresponding to the display element 10, as shown in Fig. 11D. It is configured by lining up each other successively in a direction.

The calculation means 12 performs luminance distribution (weighting calculation) on the basis of the tolerance information (overlapping information) between the unit rectangle and the contour of the character arranged corresponding to the display element 10 in the Cartesian element coordinate system. have.

In addition, in this embodiment, since the code | symbol same as the code | symbol mentioned above has shown the same or almost the same part, the description is abbreviate | omitted. In addition, since the display device 1b of the second embodiment has the same hardware configuration as that of the display device 1a shown in FIG. 2, the description of the hardware configuration will be described below with reference to FIG. .

11A while referring to FIGS. 11B, 11C, 11D, 11E, and 11F for processing of the calculation means 12 (display control section 3c) in the display device 1c as the third embodiment of the present invention. It demonstrates according to the flowchart (step A10, A20, D35, A70, D75, A80-A100) shown to the following. In addition, since the step which has the code | symbol same as the code | symbol mentioned above already shows the same or almost the same process in the figure, the detailed description is abbreviate | omitted.

Also in the example shown in Fig. 11B, font size: 5 points, font type: Gothic and serif; The example in which the font information which consists of none and the information which consists of the character code (0x83bf) which shows the character "(alpha)" was input as character information is shown.

In the display device 1c of the third embodiment, when the character code for specifying the display target character is input by the character input means 11 (step A10), the calculation means 12 inputs the input character information (font information, Based on the character code (see FIG. 11B), the font selector 12a obtains (character coded) information (outline data) about the outline font for the character to be displayed (character coded) (step A20), with respect to the character size (for example, 5 points) of the character image to be displayed, three times the size (for example, 15 points) are obtained in the longitudinal direction and the arrangement direction, respectively, and the outline of the same character of the calculated size (character outline) ) (Step D35, see FIG. 11C).

Then, the calculating means 12 converts the outline information (contour coordinates) of the characters from the pixel unit coordinates to the orthogonal element coordinates (step A70). That is, the calculation means 12 expands (maps) the calculated character outline to the orthogonal element coordinate system corresponding to the display element 10, as shown in FIG. 11D, to the display element 10 in the orthogonal element coordinate system. Based on the tolerance information (overlapping information) between the corresponding unit rectangle and the contour line, the luminance distribution (weighting calculation) is performed (step D75).

On the other hand, in the example shown in Fig. 11D, an example is shown in which character outlines (character images) are developed so as to overlap each other on a unit rectangle arranged in correspondence with the pixels of the display element 10, and character images (character outlines) in each unit rectangle. The process of determining the pixel value of the pixel corresponding to each scale is shown according to the ratio of the area where () overlaps. On the other hand, in the example shown in Fig. 11D, the percentage (overlapping rate) of the area where the character image overlaps each rectangular element is represented by percentages (0 to 100). For example, 100 is shown for a unit rectangle (100% overlap) in which a character image completely overlaps, while 0 is shown for a unit rectangle (0% overlap) in which a text image does not overlap at all, and about a unit rectangle partially overlapping. The percentage is shown in proportion to the overlapping area.

And the calculation means 12 calculates the brightness distribution to each display element 10 (unit rectangle) based on these overlap rates (overlap information).

Thereafter, the calculation means 12 performs brightness conversion (step A80, see FIG. 11E), expands the calculated (converted) luminance value in the multi-gradation memory (image memory 13b) (see steps A90, FIG. 11F). The calculation means 12 (the display control part 3) controls the light emission state of each display element 10 according to the luminance value (character image) developed in the image memory 13b, and forms the character image. A character is displayed on the display unit 2 (step A100).

FIG. 12 is a diagram (steps E10 to E30) showing a flow for explaining the display method of the character image in the display device 1c according to the third embodiment of the present invention, and the character "I" is displayed on the display unit 2. FIG. An example is shown. As shown in Fig. 12, in the display device 1c of the third embodiment, the information on the character image to be displayed is acquired (step E10), and the outline information (outline) of the character is acquired and calculated ( Step E20), a multi-gradation character image is formed on the orthogonal element coordinates (step E30).

Specifically, the character outline is mapped onto the Cartesian element coordinates, and the luminance distribution (weighting value) is based on the tolerance information (overlapping information) between the layout unit rectangle and the outline of the character corresponding to the display element 10 in the Cartesian element coordinate system. Calculation).

As described above, according to the display device 1c according to the third embodiment of the present invention, the same operation and effect as in the first embodiment can be obtained, and the character outline is directly expanded on the orthogonal element coordinates, so that the processing can be speeded up. have.

That is, the luminance of each display element 10 based on the overlapping information between each unit rectangle (rectangular display element) and the enlarged character image in the rectangular element coordinate system (orthogonal image coordinate system) formed corresponding to the display element 10. By calculating the value, the processing can be speeded up.

(D) Description of Embodiment 4

Fig. 13 is a block diagram showing the hardware configuration of the display device 1d as the fourth embodiment of the present invention.

The display device 1d according to the fourth embodiment has a plurality of rasterizers (character image creating means) 15, and has a correspondence table 16 constructed by associating a font of a character with a rasterizer for generating a character. The rasterizer corresponding to is selected with reference to this correspondence table 16, and a character image (multi-gradation character image) is generated using the selected rasterizer 15.

On the other hand, in the example shown in Fig. 13, i (i is a natural number) rasterizers 15-1, 15-2, ..., 15-i are provided, and as the reference numerals for the rasterizers, Reference numerals 15-1 to 15-i are used when one of the rasterizers needs to be specified, while reference numeral 15 is used to indicate any rasterizer. In addition, in the figure, since the code | symbol same as the code | symbol mentioned above has shown the same or almost the same part, the detailed description is abbreviate | omitted.

The rasterizer (character image generation means) 15 has functions as the character image generation unit 12b and the anti-aliasing processing unit 12c in the above-described embodiments.

Fig. 14 is a diagram showing an example of the correspondence table 16 between the font and the rasterizer used in the display device 1d as the fourth embodiment of the present invention. The correspondence table 16 is a raster for generating the font and the character of the character. It is comprised by responding to a riser. Then, for example, the font selection unit (selection unit) 12a uses the character input unit 11 to display characters on the display unit 2 based on the character information (text data and font information). The size information and outline data relating to the character are obtained from the font memory 13a, and the rasterizer 15 corresponding to the font is selected by referring to the correspondence table 16.

On the other hand, in the fourth embodiment, the font selection unit 12a functions as a selection unit for selecting an arbitrary character creation means from among a plurality of character creation steps, so that the rasterizer corresponding to the font can be selected. However, the present invention is not limited thereto, and functions as the selection unit may be provided elsewhere.

According to the display device 1d as the fourth embodiment of the present invention, the same effects and effects as those of the above-described embodiments can be obtained, and a plurality of rasterizers can be used, and among the plurality of rasterizers, It is very convenient because a character image can be generated using a corresponding rasterizer.

(E) other

FIG. 15 is a diagram showing an example of an application range of the display devices 1a, 1b, 1c, and 1d of each embodiment of the present invention. In FIG. 15, the vertical axis | shaft has shown the specification of the liquid crystal display mounting apparatus, and the horizontal axis | shaft has shown the resolution (unit: Pixels per inch (PPI)) of a liquid crystal display.

In a device with a slow processing performance, the character outline calculation takes a long time and the text display speed becomes slow. Therefore, it is preferable to use a device having a high processing performance in the practice of the present invention. In addition, a device having a panel resolution of about 120 ppi or less is suitable for displaying a character image using a dot font because of its faster processing speed (display speed). On the other hand, in the case of a device having a panel resolution of about 240 ppi or more, since the pixels themselves become precise, the superiority of the method (gradation display) of the present application is not remarkable. Therefore, it can be said that the above-described method of the present application is particularly suitable for use in a device whose pixel resolution (panel resolution) of the display means for displaying color is 120 ppi to 240 ppi.

In addition, in the above-mentioned this invention, the principle shown below is used.

① Mixed color due to visual resolution limitation.

FIG. 16 is a diagram showing the relationship between contrast sensitivity and spatial frequency (extracted from K. T Spoehr, S. W. Lehmkuhle, "Visual Information Processing").

In general, a character of about 5 points typically has an angle of view of about 0.3 degrees when viewed at a distance (eg 300 mm) from which the indicator is viewed. At this point, to separate the RGB pixels, the spatial frequency

1 / 0.3 × 7 (pixels) × 3 = 70 (cycles / degrees)

It requires some resolution.

However, as shown in Fig. 16, when the spatial frequency reaches 70 (cycles / degree), the contrast sensitivity becomes 10 or less, and it is difficult for the human eye to resolve this level of contrast sensitivity element. In this case, each color of RGB is not recognized individually, and the person perceives the mixed color.

② specificity of color perception in small field of view

It is known that when eyes are 1 degree or less, it is difficult for a human eye to distinguish colors. Therefore, in the case of observing precise RGB elements individually, extreme differences in RGB are not recognized, and the color sensation region of the eye is narrowed. Therefore, if the RGB color dispersion is at an appropriate level, the display character is mainly the brightness information is observed through the eye.

From the above-described principles of 1 and 2, it can be seen that when recognizing high-definition characters of 1 degree or less in time, RGB color information is mixed without being recognized by the eye. In the present invention, gradation of the character is performed by displaying a plurality of pixels by three elements of RGB.

In addition, since only the brightness information of mixed colors is valid, a gradation step corresponding to the brightness of each element is created.

By this, the character display in which the stroke of a character image is not enlarged is attained, and high definition character display can be implement | achieved.

In each of the above-described embodiments, the luminance gradation corresponding to the display pixel is obtained on the basis of the outline data, and when the luminance value is expanded (subpixel mapping) to the Cartesian element coordinate system corresponding to the rectangular display element 10. The generation accuracy can be improved by reducing the quantization error. That is, multi-gradation of the character images generated by the multi-gradation character generation units 1a and 4b improves the writing accuracy of the character, and eliminates distortion of the character image due to quantization error or the like.

In the case where a multi-gradation character image that has been pre-graded is developed in a subpixel, it is generally considered that coloring occurs in the character. However, in the present invention, attention is paid to the size of the pixel (rectangle display element 10) at the edge of the character to be gradated, and the occurrence of color irregularity is avoided by applying visual characteristics thereto.

When the strokes represented by Japanese display many fine characters, the portion to be multi-graded is limited to the character edges. For this reason, the gradation part is narrower (about 1 pixel or less) than the character itself. Therefore, human perceptual characteristics in a narrow area, that is, "a person's color perception ability falls when the angle of view of the object is within a few minutes" is used.

The angle of view of a 120 dpi screen from a distance of 300 mm is about 2.4 minutes. Since the viewing angle to view the gradation part is within a few minutes, the human being does not detect the color of the character edge, but only the brightness. This makes it possible to subpixel map the character image that has been previously grayscaled with the rasterizer without coloration occurring at the edges of the character.

By generating a multi-gradation character image directly from the outline data and mapping the character image to the orthogonal element coordinates, it becomes possible to display a character with higher definition than the gradation font in the coordinate system corresponding to the rectangular display element 10. At the same time, it is also possible to perform character display with subpixel mapping using a character creation process including the existing gradation processing.

In addition, the present invention is not limited to the above-described embodiments, but may be modified and practiced in various ways without departing from the spirit of the present invention.

For example, a normal display mode in which one pixel is displayed by the N display elements 10 (basic display element set 101), and each display element 10 is one or more pixels (as shown in FIG. 5A in this embodiment). Similarly, a character image is selectively selected in any mode among two modes of the fine display mode in which a plurality of pixels (9 pixels in this embodiment) are displayed by the N display elements 10 in correspondence with three pixels. Can be displayed to switch the display mode according to various conditions such as character size, font type, user setting, and the like.

That is, for example, based on the character size of the character to be displayed by the display unit 2, it is determined whether the character size is equal to or less than the preset norm size, and according to the determination result, either the normal display mode or the fine display mode. It may be determined whether to display a character image in the display mode of.

In each of the above-described embodiments, each display element is configured such that the luminance value converting unit 7 has the same brightness when the three display elements 10 of R, G, and B have the same luminance value (in the same gradation). Although the conversion process (brightness constant conversion process) which converts the brightness value with respect to (10) to the brightness value according to the brightness characteristic of each display element 10 is performed, it is not limited to this, Such brightness constant conversion process is performed. Alternatively, the element display control unit 6 may cause the display unit 2 to display a character image based on the luminance value calculated by the element luminance value calculation unit 5.

In addition, the brightness level configured with the function as the brightness value converting section 7 described above between the image memory 13a and the display section 2 in the display devices 1a, 1b, 1c, and 1d of the above-described embodiments. Each display element 10 is provided with the modulator 15 and with respect to the luminance value instruct | indicated to each display element 10 of the display part 2 from the element brightness value calculation part 5 (character image generation part 12b). You may perform the conversion process of converting into a luminance value in accordance with the brightness characteristic.

On the other hand, this luminance level modulator 15 realizes the function as the luminance value converting section 7 by hardware, for example, in an LCD controller (element luminance value calculating section 5, character image generating section 12b). This is realized by inserting an amplifier circuit into a signal transmitted to an LCD (color liquid crystal display; display portion 2). On the other hand, the RGB digital value in front of the LCD controller can also be realized by level correction by a microcomputer or the like. In addition, in the display devices 1a, 1b, 1c, and 1d of the above embodiments, the processing of the calculation means 12 (for example, the CPU of the computer system) can be reduced, and the processing speed can be increased. .

In the above-described embodiments, the case of M = 3 and N = 3 is described, but the present invention is not limited thereto, and values other than 3 may be used for each of M and N, and various modifications may be made. have.

In each of the above-described embodiments, the font memory 13a stores outline data as font information (font data) for forming a multi-value gradation character image, but is not limited thereto. Character image generation unit 12b (multi-gradation character creation unit 4) caches (temporarily stores) a multi-gradation character image created on the basis of outline data in a memory (storage device 13, etc.) When the image is to be displayed again, the subpixel gradation processing unit 12d may cause the cached multi-gradation character image to be displayed on the display unit 2, thereby improving the display speed of the character.

In addition, the font selection unit 12a stores the multi-gradation character image created by the character image generation unit 12b (the multi-gradation character creation unit 4) in advance on the basis of the outline data in the font memory 13a. The multi-gradation character image stored in the font memory 13a may be acquired, and the subpixel gradation processing unit 12d may display this character image on the display unit 2, thereby improving the display speed of the character. .

In the above-described embodiment, the subpixel gradation processing unit 12d calculates the luminance values of the display element 10 based on pixel values for each pixel column composed of three consecutive pixels. The pixel values of the pixels are averaged, but the present invention is not limited thereto. For example, pixel values of pixels (for example, pixels located in the middle) of specific positions are selected and used, or the darkest (lowest) of the three pixels is used. Various modifications can be made without departing from the spirit of the present invention, such as selecting and using pixel values. By using these methods, the display luminance of each display element 10 can be calculated | required at high speed.

In each of the above-described embodiments, an example shown in 256 gray levels of 0 to 255 as a multi-gradation character image has been described. However, the present invention is not limited to this and may be represented by other gray levels other than 256 gray levels.

In addition, in the above-described third embodiment, the calculation means 12 is based on the tolerance information (overlapping information) between the unit rectangle and the outline of the character arranged in correspondence with the display element 10 in the Cartesian element coordinate system. As a method of performing luminance distribution (weighting calculation), the luminance of each display element 10 is determined based on the ratio (overlapping ratio) of the area where the character image overlaps each rectangular element, but is not limited thereto. For example, other methods as shown below may be used.

(1) Calculate the approach distance between the center of each unit rectangle and the contour, and calculate the distribution (luminance distribution) according to the distance.

(2) Calculate the distance between the center of gravity of each unit rectangle and the contour, and calculate the distribution according to the distance.

(3) The correspondence table between the number of times the contour line crosses the long side direction of each unit rectangle and the allocation value is stored in advance, and the allocation is calculated based on this correspondence table. For example, the correspondence table between the number of times the outline of the character crosses the distribution of the unit rectangle and the distribution value (gradation value) is stored in advance, and the number of times the outline of the character crosses the long side of the unit rectangle is obtained. The distribution (gradation value) is obtained and determined by referring to the correspondence table.

(4) The correspondence table between the position where the outline crosses the long side direction of each unit rectangle and the allocation value is stored in advance, and the allocation is calculated based on this correspondence table.

17A, 17B, and 18 are diagrams for explaining another luminance distribution (weighting calculation) method in the display device as the third embodiment of the present invention, respectively, and FIG. 17A is an example of a character outline developed in Cartesian element coordinates. 17B is an enlarged view of a character outline position in a part of short-term rectangular, and FIG. 18 is a diagram showing an example of the correspondence table. The method of said (4) is demonstrated using these FIG. 17A, FIG. 17B, and FIG.

In this method, with respect to each unit rectangle constituting the Cartesian element coordinates based on the contour coordinates (contour image) developed (mapped) in the Cartesian element coordinates, the contour lines in each unit rectangle are each long side (FIG. 17A, FIG. 17A). In the example shown in FIG. 17B, positions which intersect each side in the longitudinal direction (left side, right side) in the figure are respectively acquired, and the gray scale value is determined based on these positions.

Specifically, as shown in Fig. 17B, the sides (left and right sides) in the longitudinal direction of the unit rectangle in advance are divided into a plurality of regions (four in the example shown in Fig. 17B), respectively, and these angles are divided. Information for identifying the part (numbers 0 to 3 in the example shown in Fig. 17B) is set. In addition, as long as two or more may distinguish the long side of a unit rectangle, any number may be sufficient.

Then, a correspondence table (see Fig. 18) between the position (division) and the distribution value (gradation value) at which the contour crosses the long sides of each unit rectangle is prepared, and the distribution is calculated (determining the gradation value) by referring to this correspondence table. .

For example, with respect to one unit rectangle in the rectangular coordinates shown in FIG. 17A, in the unit rectangle shown in FIG. 17B, the region of the division 1 in the character outline in either the left side or the right side (right side = left side value). = 1) passing. Based on these right side values and left side values, the gradation value 96 is acquired and determined with reference to the correspondence table shown in FIG.

Furthermore, although each of the above-described embodiments has been described with respect to the display device according to the present invention, the present invention is not limited thereto, but a display method for controlling the light emission state of each display element constituting the display unit to perform display on the display unit, or the display unit. A display control device for controlling the display state on the display unit by controlling the light emission state of each display element constituting the display element, a display control method and a character image controlling the display state on the display unit by controlling the light emission state of each display element constituting the display unit The character image generating apparatus which produces | generates may be sufficient.

Furthermore, in each of the above-described embodiments, the display unit 2, the display control units 3a, 3b, and 3c, the multi-gradation character generating units 4a and 4b, the element luminance calculating unit 5, and the element display control unit ( 6), font selection unit 12a, character image generation unit 12b, anti-aliasing processing unit 12c, subpixel gradation processing unit 12d, luminance value converting unit 7, and rasterizer (character image generating means) Numeral 15 is realized by executing a computer program, and a program for realizing these functions is provided in a form recorded in a computer readable recording medium such as a flexible disk or a CD-ROM. The computer reads the program from the recording medium, transfers it to an internal storage device or an external storage device, and stores and uses the program. The program may be recorded in a storage device (recording medium) such as a magnetic disk, an optical disk, a magneto-optical disk, or the like, and the program may be provided to the computer through the communication circuit.

Moreover, if each embodiment of this invention is disclosed, it can be manufactured by those skilled in the art.

In addition, in the present embodiment, a computer is a concept including a hardware and an operating system, and means a hardware operating under the control of the operating system. In addition, when the operating system is unnecessary and the hardware is operated by the application program alone, the hardware itself corresponds to the computer. The hardware includes at least a microprocessor such as a CPU and means for reading a computer program recorded on a recording medium. In this embodiment, the calculation means 12, the display control units 3a, 3b, 3c, and the like are used as computers. It has a function.

In addition, as the recording medium in this embodiment, the above-described flexible disk, CD-ROM, CD-R, CD-R / W, DVD, DVD-R, DVD-R / W, magnetic disk, optical disk, In addition to magneto-optical disks, computer-readable media such as IC cards, ROM cartridges, magnetic tapes, punch cards, computer internal storage devices (memory such as RAM and ROM), external storage devices, and printed materials printed with symbols such as bar codes, etc. Various media are available.

As described above, the display device, the display control device, the display method, the display control program, and the computer-readable recording medium on which the program is recorded are useful, for example, for the display of relatively small characters in a color liquid crystal display device. It is suitable for displaying monochrome characters in portable electronic devices such as mobile phones and PDAs (Personal Digital Assistants).

Claims (35)

The arrangement direction in which N rectangular display elements 10 capable of displaying different colors (N is a natural number of two or more) are orthogonal to the longitudinal direction of the rectangular display element 10 in a predetermined arrangement direction. And a display unit 2 which is formed by successively repeating a predetermined sequence in order, and capable of displaying a color image by mapping N display elements arranged in a predetermined sequence in the arrangement direction to one pixel constituting a display target image; , A multi-gradation character generating unit 4a, 4b for generating information on a multi-gradation character image obtained by gradating a character edge based on the character information on the display target character; An image memory in which the multi-gradation character image generated by the multi-gradation character generation unit is developed; An element display control unit 6 which controls each rectangular display element 10 constituting the display unit 2 to control the display state of the display unit 2. And the element display control unit 6 associates each rectangular display element 10 with one or more pixels constituting each of the multi-graded character images based on the information on the multi-gradation character image. A display device characterized by displaying a character image. The multi-gradation character generating units 4a and 4b are each characterized by M (M is a natural number) times in the length direction and N times in the arrangement direction with respect to the character size of the display target character. Generating enlarged character image information about an enlarged character image for display by causing the N rectangular display elements 10 to display 1 pixel, One rectangular display element for each pixel column composed of M pixels continuous in the longitudinal direction of the enlarged character image based on the enlarged character image information generated by the multi-gradation character generation units 4a and 4b ( An element luminance value calculating section 5 which corresponds to each of the 10 and calculates luminance values for the one rectangular display element 10 based on pixel values given to each of the M pixels. The element display control section 6 controls each rectangular display element 10 in accordance with the luminance value calculated by the element luminance value calculating section 5 to display the enlarged character image at the character size. Display). 3. The display unit 2 according to claim 2, wherein the N rectangular display elements 10 arranged in a predetermined order in the array direction form a rectangular element, The multi-gradation character generating units 4a and 4b generate, as the enlarged character image information, image information of the same character having a size of 1 times in the length direction and N times in the arrangement direction with respect to the character size of the display target character. Display device characterized in that. A device according to claim 2 or 3, wherein the element luminance value calculating section (5) includes: each rectangular display element (10) and the enlarged character image in a rectangular image coordinate system formed corresponding to the rectangular display element (10); A luminance value for the rectangular display element (10) is calculated on the basis of the overlapping information. The device luminance value calculation unit (5) according to claim 4, wherein the element luminance value calculation unit (5) calculates a luminance value for the rectangular display element (10) based on the area information of the enlarged character image overlapping the rectangular display element (10). Display device characterized in that. 5. The device luminance value calculation unit (5) according to claim 4, wherein the element luminance value calculation unit (5) is arranged at a distance between the center of each rectangular display element (10) and the outline of the enlarged character image overlapping the rectangular display element (10). A display device, characterized in that for calculating a luminance value for the rectangular display element (10). delete 5. The method of claim 4, wherein the element luminance value calculating section 5 has a number of times where an outline of the enlarged character image overlapping the rectangular display element 10 intersects the side of the rectangular display element 10 in the longitudinal direction. A display device, characterized in that for calculating a luminance value for the rectangular display element (10). 5. The position according to claim 4, wherein the element luminance value calculation unit 5 intersects the outline in the enlarged character image overlapping the rectangular display element 10 in the longitudinal direction of each rectangular display element 10. Based on the above, wherein the luminance value for the rectangular display element (10) is calculated. The luminance value of each rectangular display element 10 according to claim 2 or 3 according to the brightness characteristics of each rectangular display element 10 so that the N rectangular display elements 10 have the same brightness. And a brightness value converting section (7) for converting the brightness value into the brightness value. The multi-gradation character generating unit 4a, 4b according to any one of claims 1 to 3, And a selection unit 12a for selecting an arbitrary multi-gradation character generation unit 4a, 4b from the plurality of multi-gradation character generation units 4a, 4b based on font type information as the character information. Display device. 4. The device luminance value calculating unit according to claim 2 or 3, wherein the element luminance value calculating unit 5 distributes the luminance for each coordinate corresponding to the shape of the display element on the basis of the calculated luminance value. A display device characterized in that the value at which the brightness balance of the display element is applied is the luminance value of the character image. The display device according to any one of claims 1 to 3, wherein the pixel resolution of the display unit (2) is 120 ppi (pixels per inch) to 240 ppi. The arrangement direction in which N rectangular display elements 10 capable of displaying different colors (N is a natural number of two or more) are orthogonal to the longitudinal direction of the rectangular display element 10 in a predetermined arrangement direction. The display unit 2 is formed by successively repeating a predetermined sequence in a predetermined order, and the display unit 2 capable of displaying a color image by associating N display elements arranged in a predetermined sequence in the arrangement direction with one pixel of a display target image. It is a display control apparatus which performs control for displaying a character, A multi-gradation character generating unit 4a, 4b for generating information on a multi-gradation character image obtained by gradating a character edge based on the character information on the display target character; An image memory in which the multi-gradation character image generated by the multi-gradation character generation unit is developed; An element display control unit 6 for controlling the rectangular display elements 10 constituting the display unit 2 to control the display state of the display unit 2, The element display control section 6 associates each rectangular display element 10 with one or more pixels constituting a multi-graded character image based on the information about the multi-gradation character image to display the multi-gradation character image. A display control device characterized by displaying. 15. The character of claim 14, wherein the multi-gradation character generating units 4a and 4b each have M (M is a natural number) times in the length direction and N times in the arrangement direction with respect to the character size of the display target character. Generating enlarged character image information about an enlarged character image for display by causing the N rectangular display elements 10 to display 1 pixel, One rectangular display element for each pixel column consisting of M pixels continuous in the longitudinal direction in the enlarged character image based on the enlarged character image information generated by the multi-gradation character generating units 4a and 4b. An element luminance value calculating section 5 which corresponds to each of the 10 and calculates luminance values for the one rectangular display element 10 based on pixel values given to each of the M pixels, The element display control section 6 controls each rectangular display element 10 in accordance with the luminance value calculated by the element luminance value calculating section 5 to display the enlarged character image at the character size in the display unit ( Display control apparatus characterized by the above-mentioned. The display unit 2 according to claim 15, wherein the N rectangular display elements 10 arranged in a predetermined order in the array direction form a rectangular rectangle element. The multi-gradation character generating units 4a and 4b generate, as the enlarged character image information, image information of the same character having a size of 1 times in the length direction and N times in the arrangement direction with respect to the character size of the display target character. Display control device characterized in that. 17. The device of claim 15 or 16, wherein the element luminance value calculating section (5) includes: each rectangular display element (10) and the enlarged character image in a rectangular image coordinate system formed corresponding to the rectangular display element (10); A luminance value for the rectangular display element (10) is calculated on the basis of the overlapping information. 18. The method according to claim 17, wherein the element luminance value calculation unit 5 calculates a luminance value for the rectangular display element 10 based on area information of the enlarged character image overlapping the rectangular display element 10. Display control apparatus characterized by the above-mentioned. 18. The position according to claim 17, wherein the element luminance value calculating section 5 intersects an outline in the enlarged character image overlapping the rectangular display element 10 in the longitudinal direction of each rectangular display element 10. Based on the above, wherein the luminance value for the rectangular display element (10) is calculated. The luminance value of each rectangular display element 10 according to the brightness characteristics of each rectangular display element 10 according to claim 15 or 16, so that the N rectangular display elements 10 have the same brightness. And a brightness value converting section (7) for converting the brightness value into the brightness value. 17. The apparatus according to any one of claims 14 to 16, comprising a plurality of the multi-gradation character generating units 4a, 4b, And a selection unit 12a for selecting an arbitrary multi-gradation character generation unit 4a, 4b from among the plurality of multi-gradation character generation units 4a, 4b based on font type information as the character information. Display control device. The value according to claim 15 or 16, wherein the element luminance value calculating unit 5 distributes the luminance for each coordinate corresponding to the shape of the display element, and applies the brightness balance of the display element to the allocation value. The display control apparatus characterized by setting the brightness value of the character image. 17. The display control device according to any one of claims 14 to 16, wherein the pixel resolution of the display portion (2) is 120 ppi (pixels per inch) to 240 ppi. The arrangement direction in which N rectangular display elements 10 capable of displaying different colors (N is a natural number of two or more) are orthogonal to the longitudinal direction of the rectangular display element 10 in a predetermined arrangement direction. The display unit 2 is formed by successively repeating a predetermined sequence in a predetermined order, and the display unit 2 capable of displaying a color image by associating N display elements arranged in a predetermined sequence in the arrangement direction with one pixel of a display target image. The display method of displaying characters. A multi-gradation character generation step of generating information on a multi-gradation character image obtained by gradating a character edge based on the character information on the display target character; A development step of developing a multi-gradation character image generated in the multi-gradation character generation step into an image memory, An element display control step of controlling the rectangular display elements 10 constituting the display unit 2 to control the display state of the display unit 2, In the element display control step, based on the information about the multi-gradation character image, each rectangular display element 10 is associated with one or more pixels constituting the multi-gradation character image, respectively, to display the multi-gradation character image. Display method characterized in that. 25. The method according to claim 24, wherein in the multi-gradation character generating step, M (M is a natural number) times in the length direction and N times the same characters in the arrangement direction with respect to the character size of the display target character, Enlarged character image information relating to an enlarged character image for display by causing one pixel display to be performed by two rectangular display elements 10, On the basis of the enlarged character image information generated in the multi-gradation character generation step, one rectangular display element 10 is formed for each pixel column consisting of M pixels continuous in the length direction of the enlarged character image. An element luminance value calculating step of calculating a luminance value for the one rectangular display element 10 based on a pixel value given to each of the M pixels, In the element display control step, the rectangular display elements 10 are controlled in accordance with the luminance values calculated in the element luminance value calculating step so that the enlarged character image is displayed on the display unit 2 in the character size. Display method characterized in that. The display unit 2 according to claim 25, wherein the N rectangular display elements 10 arranged in a predetermined order in the arrangement direction form a rectangular rectangle element. In the multi-gradation character generating step, image information of the same character having a size of 1 times in the length direction and N times in the arrangement direction with respect to the character size of the display target character is generated as the enlarged character image information. How to show. 27. The method according to claim 25 or 26, wherein in the element luminance value calculating step, the rectangular display elements 10 and the enlarged character image overlap each other in the rectangular image coordinate system formed corresponding to the rectangular display elements 10. Based on the information, a luminance value for the rectangular display element (10) is calculated. The luminance value of the rectangular display element 10 is calculated in the device luminance value calculating step according to claim 27, wherein the luminance value of the rectangular display element 10 is calculated based on the area information of the enlarged character image overlapping the rectangular display element 10. Display method. 28. The device luminance value according to claim 27, wherein in the element luminance value calculating step, an outline of the enlarged character image overlapping the rectangular display element 10 intersects a side of the rectangular display element 10 in the longitudinal direction. And a luminance value for the rectangular display element (10). 27. The brightness of the rectangular display elements 10 according to the brightness characteristics of each rectangular display element 10 according to claim 25 or 26, so that the N rectangular display elements 10 have the same brightness. And a brightness value converting step of performing a conversion process of converting the brightness value. 27. The apparatus according to any one of claims 24 to 26, further comprising a plurality of multi-gradation character generation means for realizing the multi-gradation character generation step, And a selection step of selecting an arbitrary multi-gradation character generation means from the plurality of multi-gradation character generation means based on font type information as the character information. 27. The device luminance value according to claim 25 or 26, wherein in the element luminance value calculating step, luminance is distributed for each coordinate corresponding to the shape of the display element, and the value obtained by causing the brightness balance of the display element to act on the allocation value is characterized. A display method comprising the luminance value of an image. 27. The display method according to any one of claims 24 to 26, wherein the pixel resolution of the display unit (2) is 120 pixels per inch (ppi) to 240 pixels per inch. delete The arrangement direction in which N rectangular display elements 10 capable of displaying different colors (N is a natural number of two or more) are orthogonal to the longitudinal direction of the rectangular display element 10 in a predetermined arrangement direction. The display unit 2 is formed by successively repeating a predetermined sequence in a predetermined order, and the display unit 2 capable of displaying a color image in correspondence with one pixel constituting a display target image by N display elements arranged in a predetermined sequence in the arrangement direction. A computer-readable recording medium having recorded thereon a display control program for controlling the display. The display control program, A multi-gradation character generating unit 4a, 4b for generating information on a multi-gradation character image obtained by gradating an edge based on the character information on the display target character; An image memory in which the multi-gradation character image generated by the multi-gradation character generation unit is developed; The computer functions as an element display control unit 6 for controlling the rectangular display elements 10 constituting the display unit 2 to control the display state of the display unit 2, The element display control section 6 associates each rectangular display element 10 with one or more pixels constituting a multi-graded character image based on the information about the multi-gradation character image to display the multi-gradation character image. And a computer readable recording medium having recorded thereon a display control program to cause the computer to display.

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