JPH04324571A - Character display device - Google Patents

Abstract

PURPOSE:To change the size of displayed characters without increasing the storage capacity of a memory by compressing stored data of a character font pattern on specific OR logic of plural dots and displaying the characters with the data. CONSTITUTION:A CPU 1, ROM 2, and RAM 3 make a display 6 to display a navigation map, etc., by controlling the display of the display 6, etc. In order to display characters, in addition, the ROM 2 stores data of a character font pattern of 16X16 dots. After the data of the character font pattern of 16X16 dots are read out from the ROM 2 and the data are divided into 4-dot units at every line, the data are subjected to data conversion for compressing the data in the direction of row so that the value obtained by ORing the values of the 2nd and 3rd dots can become the value of the 2nd dot, while the first and last dots are left as they are and the display 6 displays characters by using the converted data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character display device for displaying characters, and particularly to one in which the size of displayed characters can be changed.

0002

2. Description of the Related Art Conventionally, in this type of character display device, character font pattern data is stored in advance.
Characters are displayed on the display device using the character font pattern data.

0003

[Problems to be Solved by the Invention] However, if the display device is to be installed inside the vehicle, such as an in-vehicle display device, it is necessary to downsize the display device. In the case where a map is displayed overlappingly on a navigation device, there is a restriction on the number of characters displayed on one screen. Therefore, it is necessary to deal with this by changing the size of the displayed characters.

[0004] In this case, in the above conventional system, the size of the displayed characters is constant, so if you want to change the size of the displayed characters, you have to memorize character font patterns of several sizes in advance. The size of the displayed characters must be changed based on the selection.

[0005] In this way, storing many types of character font patterns for displaying the same character is
This results in an increase in the capacity of the storage means, making it impractical. The present invention has been made in view of the above problems, and an object of the present invention is to enable changing the size of displayed characters without increasing the storage capacity of the storage means.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a display means for displaying characters using a plurality of pixels;
The display means includes a storage means for storing character font pattern data of n dots by m dots, and a display control means for reading the character font pattern data from the storage means and causing the display means to display the characters. In the character display device, the display control means reads character font pattern data from the storage means, divides the n dots and/or m dots into units of a predetermined number of dots, and displays a specific plurality of dots in the divided units. The present invention is characterized in that it includes a data conversion means that performs OR logic of dot values and compresses character font pattern data.

[0007]

[Operation] In the above configuration, the data of the character font pattern read from the storage means is compressed by the data conversion means using a specific OR logic of multiple dots, and the data of the character font pattern read out from the storage means is compressed by the data of the compressed character font pattern. Characters are displayed on the display device.

[0008]

[Embodiments] The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is a configuration diagram showing one embodiment thereof. In FIG. 1, a CPU 1, a ROM 2, and a RAM 3 are control units that control the display of the display 6, and although sensors and the like are not shown, the display 6 causes the display 6 to display a map during navigation. In addition, in order to display characters in this map display, ROM2 contains multiple types of 16
*16 dot character font pattern data is stored. The stored character font pattern data is temporarily stored in the RAM 3, and converted into 12 dots by 16 dots by a conversion program stored in the ROM 2, which will be described later. Then, the converted 12 dots x
The data of 16 dots is stored in VRAM5. CRT
The controller (CRTC) 4 causes the display 6 to display characters based on the stored 12 dots x 16 dots data.

Next, the above conversion program will be explained. In FIG. 2, this conversion program is performed in step 10.
The process starts from 1 and reads data f16 (x, y) of a character font pattern of 16 dots x 16 dots. In the next step 102, data initialization (H=0
, V=0). These H and V indicate data matrices. Note that f12 (x, y) shown below indicates data of a 12 dot x 16 dot character font pattern after conversion.

Thereafter, in steps 103 to 111, data obtained by dividing each line into four-dot units is converted. First, in step 103, a process is performed in which the value of the first dot of the four dots is used as the value of the converted dot. That is, f16 (4V+0, H) is H
f12 (3V+0, H) indicates the value of the first dot when the line is divided into 4-dot units, and f12 (3V+0, H) indicates the value of the first dot when the H line after conversion is divided into 3-dot units. have the same value.

In the next step 104, f16 (4V+
1, H), f16 (4V+2, H) is 1. 1 means that it is one component of the character display. Also, f16 (4V+1,
H), f16 (4V+2, H) means 4 H rows each.
It shows the values of the second and third dots when divided into dots. If this judgment becomes YES,
Proceed to step 105 and set f12 (3V+1, H) to 1. This f12 (3V+1, H) indicates the value of the second dot when the H row after conversion is divided into 3 dot units. If the determination in step 104 is NO, the process proceeds to step 106 and f12 (3V+1, H) is set to 0. That is, in steps 104 to 106 above, the result of ORing the inner two dots when divided into four dot units is used as the value of the second dot when the converted H line is divided into three dot units. Perform processing.

In the next step 107, a process is performed in which the value of the last dot of the four dots is used as the value of the converted dot. The above processing is performed on the 4 dots in the H line, and in the case of 16 x 16 dot character font pattern data, each line consists of 4 combinations of 4 dots, so
The above steps 103 to 108 are repeated until V reaches 4. When V reaches 4, it is assumed that the processing for one row is completed, and in order to process the next row, step 1 is performed.
In step 10, H is updated by 1, and the above process is performed on the updated row.

Therefore, by the above process, as shown in FIG. 3, when each line is divided into 4 dots, the first and last dots remain unchanged, and the OR logic value of the inner two dots becomes the second dot. Data conversion is performed to obtain data.

[0014] When H becomes 16, that is, when data conversion for all lines is completed, the determination in step 111 becomes NO, and data conversion for one character in this conversion program is completed. Note that data conversion similar to the above is performed for other characters as well.

In the above embodiment, data is compressed in the column direction, but the conversion program may be arranged to compress data in the row direction.
Furthermore, data compression may be performed in both the row and column directions.

In other words, in FIG. 4, the 16×16
Display examples are shown when data is compressed in the column direction, when data is compressed in the row direction, and when data is compressed in both the row and column directions for the base data of the dot character font pattern. Display characters of a desired size can be created using the conversion program as described above.

Note that in the above embodiment, 16×16 dots in character font pattern data are divided into 4 dots, and the values of the inner 2 dots of the 4 dots are ORed.
It takes logic and compresses data into 3-dot units and converts it into 12 dots x 16 dots. Compression that converts 4 dots into 3 dots makes it especially difficult for the visual recognition of displayed characters. This is based on the various considerations of the present inventors that it is possible to display compressed characters in a good manner without impairing the character. Data compression of the character font pattern may be used.

[0018]

As described above, according to the invention as set forth in claim 1, data of a character font pattern stored in the storage means is converted into O of a specific plurality of dots by the data conversion means.
Since data is compressed using R logic and characters are displayed using the compressed character font pattern data, the storage capacity of the storage means is not increased.
This has the excellent effect of being able to change the size of displayed characters.

Furthermore, as described in claim 2, the n dots and/or m dots in the data of the character font pattern are divided into four dot units, and the OR logic of the values of the inner two dots of the four dots is performed. Compressing the data into 3-dot units has an excellent effect in that compressed characters can be displayed in good quality without impairing the visibility of displayed characters.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a conversion program.

FIG. 3 is an explanatory diagram used for conversion processing.

FIG. 4 is a diagram showing an example of displaying character variations.

[Explanation of symbols]

1 CPU 2 ROM 3 RAM 4 CRT controller 5 VRAM 6 Display

Claims (2)

[Claims] 1. A display means for displaying characters using a plurality of pixels, a storage means for storing data of a character font pattern of n dots by m dots in the display means, and a data of a character font pattern read from the storage means. and display control means for causing the display means to display characters, the display control means reads data of a character font pattern from the storage means, and causes the n dots and/or m dots to be displayed in a predetermined manner. 1. A character display device comprising a data conversion means for compressing data of a character font pattern by dividing the data into a number of dot units and performing OR logic of the values of specific plurality of dots in the divided units. 2. The data conversion means divides the n dots and/or m dots in the character font pattern data into 4 dot units, performs an OR logic on the values of the inner two dots of the four dots, and performs an OR logic on the values of the inner two dots of the four dots. A character display device that compresses data into dot units.