JPH03210592A - image display device - Google Patents

Abstract

PURPOSE:To provide color data with interchangeability by providing the image display device with an image signal generating means, an expanded image signal generating means and an image signal converting means. CONSTITUTION:An 8-bit image signal generating circuit exchanges upper four bits GD7 to GD4 and lower four bits GD3 to GD0 each other by an image signal converting circuit 13. The converted data KD7 to KD0 are inputted to a D/A converter 12 to generate data HD to be outputted to the image display device. On the other hand, an image signal converting circuit 21 replaces upper 4-bit data and the lower 4-bit data such as GD7-GD3, GD6-GD2, GD5-GD1, and GD4-GD0. Consequently, interchangeability between the 4-bit data and the color data of a certain determined image signal consisting of five bits or more can be attained in the image signal forming circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an image display device in an information processing device.

[Prior Art] In an image signal generation device included in an information processing device, conventional image signals are basically three colors of red, green, and blue, and some colors are output to a display device and displayed by a combination of the three colors. are doing. Among them, in information processing equipment, as shown in Figure 3,
The color information memory section 31 has color data of 4 bits each for each of the above three colors, and the color information memory section 3 stores the color information data necessary for displaying the image signal on the screen of the image display device.
1 and converts the 4-bit data into digital image signals GDR3 to GDRO, GDG3 to GDGO1GD8 using a digital to analog converter (hereinafter referred to as a D/A converter) in the digital/analog converter 32.
3 ~ Analog image signals HDR, HDG from GDBo,
) (converted to DB. Therefore, a total of three analog signals, one signal for each color, are generated from the 12-bit digital signals for the three colors and output to the image display device.

Since the information processing device having the image signal generation circuit shown in Fig. 3 uses a total of 12 bits of digital signals for three colors, 4096 (2+2=4096) color combinations are possible, and a maximum of 4096 It is possible to display colors of colors on an image display device. Next, in Figure 5, the data for each color of red, green, and blue is 8 bits, a total of 24 bits, so there are 16777216 ways (224 = 16777216
) shows an image signal generation circuit that can perform M matching.

The 4-bit image signal generation circuit shown in FIG. 4 uses the lower 4 bits D3 to DO of the 8-bit system data bus of the information processing device.

Also, in the 8-bit image signal generation circuit shown in Figure 6, all eight system data buses (8 bits) D7 to DO are used.

In both cases, data is stored in the color information memory of the image signal, and when displaying the image, the data is read out from this color information memory and the digital signal for image display is converted into 4-bit or 4-bit data using a D/A converter. 8-bit data is converted into an analog signal and output to an image display device. Figure 4,
The circuit shown in FIG. 5 uses the data written in the color data memory as it is as data for D/A conversion.

[Problem H to be solved by the invention] In the conventional technology, as long as the digital data of each color of red, green, and blue is 4 bits as shown in GD3 to GDO in FIG. 4, the color data can be output to the image display device. It is impossible to have more than 4096 HD sheath combinations. Therefore, in order to reduce the number of colors displayed on the image display device to more than 4096, the digital data of each color of red, green, and blue output from the color information memory section 31 shown in FIG.
It is necessary to increase the number of bits, such as 6 bits. If the data for each color is expanded to 8 bits as shown in Figure 5, the combination of color data HD that can be output to the image display device is red, green, and blue, and the digital data totals 2.
Since 4 bits can be used, 16777216 colors (22'=16777216), that is, more than 16.7 million colors can be displayed on the screen of the display device. As shown in Fig. 4, the 4-bit image signal generation circuit uses the lower 4 bits D3 to DO of the system data bus of the information processing device and does not use the upper 4 bits D7 to D4. In the 8-bit image signal generation circuit shown in Figure 5, the 8-bit system data bus D7 to DO of the information processing device
I am using Suhete.

In this case, there is a problem in that the data used in the 4-bit image signal generation circuit and the data used in the 8-bit image signal generation circuit must be completely independent and incompatible data. .

[Means for Solving the Problems] The present invention provides an image signal processing mechanism of an information processing device, which includes:
The image signal processing mechanism includes image signal generation means for an arbitrary number of bits, extended image signal generation means for an expanded number of bits than the arbitrary number of bits, and extended image signal generation means for the expanded number of bits for the image signal generation means. and an image signal conversion means whose color information data is compatible with each other.

[Example] An embodiment of the image signal generation circuit of the present invention will be described below.

FIG. 1 is a schematic diagram of an 8-bit image signal generation circuit using the present invention. Color data of a 0 image signal is written in a color information memory 11, and color data is read from this color information memory when displaying an image. However, the image signal conversion circuit 13 converts the upper 4 bits CD7 to GD4 and the lower 4 bits GD3 to G.
Exchange DO. This converted data KD7~KDO
is input to the D/A converter 12 to generate data HD to be output to the image display device. The D/A converter [2] used in the circuit for generating the image signal display data HD has a weight relative to the input upper data KD7 and the output signal. On the other hand, lower-order data KDO has a lighter weight relative to its output signal.

As shown in Figure 2, data GD7 and GD3, CD6 and C
In the image signal conversion circuit 21, the upper 4 bits of data and the lower 4 bits are
Bit data is being replaced. (Hereinafter, this data swapping will be referred to as data swapping.) The 4-bit image signal generation circuit shown in FIG. 4 uses the lower 4 bits D3 to DO of the system data bus. This 4
Bit data is input to a 4-bit D/A converter 42 to generate data to be output to an image display device.

Therefore, in this case, the upper 4 bits of data D7 to D4 of the system data bus of the information processing device are completely ignored. Therefore, the 8-bit image signal generation circuit uses the upper 4 bits of the system data bus of the information processing device, which are not used by the 4-bit image signal generation circuit. In the conventional 8-bit image signal generation circuit as shown in FIG. Data D
7 has the most weight.

However, in the image signal generation circuit of the present invention shown in FIG. 1, the data read from the color information memory 11 is swapped in the image signal conversion circuit 13, so when writing color data to the color information memory, swaps the upper 4 bits D7 to D4 and the lower 4 bits D3 to Do in advance. As a result, the data weight in the data written to the color information memory is the most significant of the lower 4 bits, that is, D
3 will be the heaviest. This means that when viewed from the perspective of the weight of color data written to the color information memory, the highest order D3 of the lower 4 bits has the highest weight among the color data written to the color information memory, and D2, DI, Do This is consistent with the case of the 4-bit image signal generation circuit described earlier in that the weight of data becomes lighter in order. Among the color data to be written into the memory, the lower 4 bits of the 8 pins of the system data bus of the information processing device have weights in the order of D3, D2, Dl, and DO with respect to the output data HD of the D/A converter, In the 8-bit image signal generation circuit, the upper 4 bits of data D7 to D4, which were not used in the 4-bit image signal generation circuit, are added to the 8-bit image signal generation circuit.
Considering this as data for gradation expansion, the 8-bit image signal generation circuit can be positioned as an extension of the 4-bit image signal generation circuit.

Additionally, this concept can be applied not only when the number of bits of color data is less than 8 bits, such as 5 bits, 6 bits, and 7 bits, but also when it is 9 bits or more. By using the present invention, the lower 4 bits of data of the system data bus and 8
It is possible to make the color data compatible in that the same data can be used for the lower 4 bits of the system data bus to be written into the color information memory of the bit image generation circuit.

[Effects of the Invention] As described above, according to the present invention, it is possible to make 4-bit color data compatible with color data of an image signal having a number of S bits or more in an image signal generation circuit.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of an image signal generation circuit according to the present invention. Figure 2 is a diagram of an image signal conversion circuit according to the present invention. Figure 3 is a diagram of a conventional image signal generation circuit. Figure 4 is a 4-bit image signal generation circuit. 5 is a diagram of an 8-bit image signal generation circuit. 11...Memory for 8-bit color information 12...8-bit D/A converter 13...Image signal conversion circuit 21...Image signal conversion circuit 31...Memory for color information Section 32...Digital-to-analog conversion section 4I...
4-bit color information memory 42...4-bit D/A converter 51...8-bit color information memory 52...8-bit D/A converter or higher

Claims (1)

[Claims] In an image signal processing mechanism of an information processing device, the image signal processing mechanism includes an image signal generation means with an arbitrary number of bits, an extended image signal generation means with a bit number expanded than the arbitrary number of bits, and the image signal generation means. and an extended image signal generating means having an expanded number of bits.