JPH06178237A - Display device - Google Patents

Abstract

PURPOSE:To provide the display device capable of attaining uniform display on the entire screen even when the number of dots of an inputted video signal is less than a fixed picture element number of a fixed picture element display element. CONSTITUTION:The display device is provided with sample-and-hold circuits 2a-2n sampling sequentially each video signal 1, multiplier circuits 8a-8n calculating respectively each energy supposed to be obtained by each of fixed picture elements 7a-7n with an electron beam having a predetermined energy distribution through the tentative scanning on each of the fixed picture elements 7a-7n corresponding to each video signal 1 sampled by each of the sample-and-hold circuits 2a-2n and adder circuits 9a-9n adding each energy calculated by the multiplier circuits 8a-8n to calculate respectively the brightness of each of the fixed picture elements 7a-7n.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using fixed pixel display elements such as liquid crystal display elements and plasma display elements.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a driving unit of a fixed pixel display element of a conventional display device disclosed in Japanese Patent Publication No. 3-32175. In the figure, 1 is a video signal of a plurality of dots to be input, 2a to 2n are sample hold circuits for sampling and storing each of these video signals 1, 3a to 3n are memories, 4a to 4n are drive circuits, 5
Is a sample pulse generation circuit for outputting sampling pulses 5a-5n to the sample-hold circuits 2a-2n and a load pulse 6 for the memories 3a-3n, 7
Is a fixed pixel display element including a plurality of fixed pixels.

Next, the operation of the drive section of the conventional display device constructed as described above will be described. First, each video signal 1 input to the driving unit is generated by the sample pulse generating circuit 5 and each sample and hold circuit 2a to 2n.
Sampling pulses 5a to 5n respectively supplied to the
Thus, the sample and hold circuits 2a to 2n are sequentially sampled and stored. In this case, there is a one-to-one correspondence between the number of dots in the horizontal direction of each video signal 1 to be displayed and the number of fixed pixels of the fixed pixel display element 7. That is, the sampling pulse 5a is output from the sample pulse generation circuit 5 at the timing when the first dot of the video signal 1 is input, and the initial video signal 1 is sampled and stored in the sample hold circuit 2a.

Further, when the next one dot of the video signal 1 is input, the sample pulse generating circuit 5 is operated as described above.
A sampling pulse 5b is output from the video signal 1 and the video signal 1 is sampled and stored in the sample hold circuit 2b. Thereafter, the same operation is repeated, the n-th video signal 1 is sampled and stored in the sample hold circuit 2n, and when sampling to all the sample hold circuits 2a to 2n is completed, at this point, the sample pulse generation circuit 5 Load pulse 6 is output to each of the memories 3a to 3n, each video signal 1 stored in each of the sample and hold circuits 2a to 2n is transferred to each of the memories 3a to 3n, and then passed through each of the drive circuits 4a to 4n. An image is displayed on the fixed pixel display element 7 by being displayed on each fixed pixel.

[0005]

In the conventional display device, the drive section is configured as described above, and the number of dots of the input video signal 1 and the number of pixels of the fixed pixel display element 7 have a one-to-one relationship. Therefore, when a video signal 1 having a smaller number of dots than the number of pixels is input, it can be displayed by inputting only the number of dots of the video signal 1 to the sample hold circuit, but the fixed pixel of the fixed pixel display element 7 is displayed. Since the display size is small and the entire screen is not used because it is displayed only in a part of the area, if each dot of the video signal 1 is sampled by the same number as the fixed number of pixels, it can be displayed in all the fixed pixels. You can use the entire screen, but video signal 1
There is a problem in that the correspondence of the fixed pixel number of the 1-dot-to-fixed pixel display element 7 is not constant, and the 1 dot that should be originally displayed in the same size changes depending on the position of the screen.

The present invention has been made to solve the above problems, and even when the number of dots of an input video signal is smaller than the fixed number of pixels of a fixed pixel display element, it is uniform over the entire screen. It is an object of the present invention to provide a display device capable of displaying images.

[0007]

A display device according to the present invention is predetermined so as to correspond to a sample hold circuit for sequentially sampling each video signal and each video signal sampled by this sample hold circuit. A multiplication circuit that virtually scans each fixed pixel with an electron beam having an energy distribution to calculate each energy value assumed to be obtained by the fixed pixel by the electron beam for each fixed pixel, and this multiplication circuit. And an adder circuit for calculating the brightness of each fixed pixel by adding the values of the respective energies calculated by the circuit.

[0008]

In the multiplication circuit and the addition circuit of the display device according to the present invention, even when a screen having a resolution in which the number of dots of the input video signal is smaller than the fixed number of pixels of the fixed pixel display element is displayed, it is fixed to one dot of the signal. 1 displayed on a pixel
Keep the relationship with dots constant across the screen.

[0009]

EXAMPLES Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a drive unit of a fixed pixel display element of a display device according to Embodiment 1 of the present invention, and FIG. 2 is a diagram for explaining the concept of the present invention. In the figure, the same parts as those of the conventional device shown in FIG. Reference numerals 7a to 7n are fixed pixels of the fixed pixel display element, 8a to 8n are multiplication circuits, 9a to 9n are addition circuits, 10 is a distribution waveform of a virtually introduced electron beam, and 11a to 11h are sample and hold circuits 2a. ~ 2
Fixed pixel 7a with the waveform of the video signal input to h
The number of dots is less than the number of ~ 7n.

Next, before explaining the operation of the display device in the embodiment 1 configured as described above, the basic concept for determining the brightness of each of the fixed pixels 7a to 7n of the fixed pixel display element 7 will be described. 2 will be described. First, when displaying n fixed pixels with a video signal having a dot number smaller than the fixed pixel number n, the brightness of the n fixed pixels must be determined and emitted by a signal having a dot number smaller than n. The size of one dot of the signal on the screen must be set larger than the size of one fixed pixel. That is, for example, in FIG.
It is necessary to make both fixed pixels 7a and 7b shown in FIG. 2A emit light by the video signal 11a shown in FIG.

Therefore, as shown in FIG. 2B, the size of one dot of the video signal is increased so that each video signal 1
1a to 11b are set so as to correspond to the sizes of the fixed pixels 7a to 7n, and the video signal 1 set in this way is set.
An electron beam having a predetermined energy distribution corresponding to 1a to 11h is virtually scanned on each of the fixed pixels 7a to 7n to obtain the energy assumed to obtain the center of each of the fixed pixels 7a to 7n. If the brightness of each of the fixed pixels 7a to 7n is estimated to be proportional and the brightness of each of the fixed pixels 7a to 7n is determined, the image can be displayed uniformly over the entire screen.

More specifically, the fixed pixel 7
At the center point of a, the total energy of the distribution is obtained by scanning the beam corresponding to the signal 11a, but at the center point of the fixed pixel 7b, the scanning of the beam corresponding to the signal 11a goes only to the center point. % By the beam corresponding to the signal 11a, and the remaining 50% is the signal 11b.
Will be obtained from the beam corresponding to. That is, the brightness of the fixed pixel 7a is proportional to (signal 11a * 1), and the brightness of the fixed pixel 7b is (signal 11a * 0.5) + (signal 11b).
* Proportional to 0.5). The relationship between these is the number n of fixed pixels of the fixed display element 7 and the signal 1 to be displayed.
It can be obtained by defining the number of dots in the circle and the assumed energy distribution of the beam.

A first embodiment in which the above concept is shown in FIG.
, The video signal 11a causes the fixed pixel 7a to emit light as it is. Therefore, the coefficient of the multiplication circuit 8a is Aa = 1, other than Aa = 0, and the coefficient of the multiplication circuit 8b is Ba = 0. 5, Bb = 0.5, Ba,
Coefficients after the multiplication circuit 8c are sequentially set such that 0 other than Bb. Therefore, after each video signal 1 input and stored in each of the sample hold circuits 2a to 2h is multiplied by each coefficient set as described above in each of the multiplication circuits 8a to 8h and resolution conversion is performed. , Each fixed pixel 7 is added by each addition circuit 9a to 9h.
The brightness of a to 7n is determined, and the image is displayed uniformly over the entire screen.

Example 2. In the first embodiment described above, the fixed pixels 7a to 7n are generally connected to n multiplication circuits (for example, Aa to An in the case of 8a). With resolution conversion up to about / 2, even if two to three multiplication circuits are connected to each fixed pixel, the same effect as in the case of the first embodiment can be obtained.

Example 3. In the first embodiment described above, the case of performing resolution conversion in the horizontal direction has been described, but in the third embodiment, the case of performing resolution conversion in the vertical direction will be described. FIG. 3 is a diagram for explaining the concept of resolution conversion of a display device in Embodiment 3 of the present invention. In the figure, 7L _{1 to} 7L _n correspond to the number of rows of the fixed pixel display element 7 in the same manner as in the above-described first embodiment because the number of rows of the fixed pixel display element 7 is smaller than m. The energy distribution of the electron beam is set so as to correspond to the signal thus set.

For example, as shown in FIG. 3, about 80% of the energy 12a of the electron beam in the first signal line causes the pixel L ₁ row of the fixed pixel display element to emit light, and the pixel L ₂ row has energy 1 a.
Light is emitted by the remaining 20% of 2a and 20% of the energy 12b of the electron beam in the second row. Therefore, similar to the resolution conversion in the horizontal direction described in the first embodiment, if the brightness is calculated for each pixel row by the multiplication circuit and the addition circuit, an image is displayed uniformly over the entire screen. Note that each coefficient for resolution conversion in the arithmetic circuit is
It is necessary to determine and obtain the assumed energy distribution of the electron beam so that the converted image has the best visibility.

[0017]

As described above, according to the present invention, a sample hold circuit for sequentially sampling each video signal, and a predetermined energy distribution corresponding to each video signal sampled by the sample hold circuit. A multiplication circuit that virtually scans each fixed pixel with an electron beam having the following, and calculates each energy value for each fixed pixel that is assumed to be obtained by the fixed pixel by the electron beam, and this multiplication circuit Since an addition circuit that adds the calculated energy values and calculates the brightness of each fixed pixel is provided, when the number of dots of the input video signal is less than the number of fixed pixels of the fixed pixel display element. Also, it is possible to provide a display device capable of displaying uniformly over the entire screen.

[Brief description of drawings]

FIG. 1 is a block diagram showing a drive unit of a fixed pixel display element of a display device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the concept of the present invention.

FIG. 3 is a diagram illustrating a concept of resolution conversion of a display device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a driving unit of a fixed pixel display element of a conventional display device.

[Explanation of symbols]

1 11a to 11h Video signal 2a to 2h Sample and hold circuit 3a to 3n Memory 4a to 4n Drive circuit 5 Sample pulse generation circuit 5a to 5c Sampling pulse 6 Load pulse 7 Fixed pixel display element 7a to 7n Fixed pixel 7L _{1 to} 7L _m pixel Row 8a to 8n Multiplier circuit 9a to 9n Adder circuit 10, 12a, 12b Distribution of electron beam

Claims (1)

[Claims] 1. A display device for displaying an image by resolving a video signal having a dot number smaller than the input pixel number to a fixed pixel display element having a predetermined pixel number,
A sample and hold circuit for sequentially sampling each of the video signals, and an electron beam having a predetermined energy distribution corresponding to each of the video signals sampled by the sample and hold circuit are virtually projected on each of the fixed pixels. A scanning circuit for calculating each energy value assumed to be obtained by the electron beam for each fixed pixel for each fixed pixel, and a value for each energy calculated by this multiplication circuit. A display device, comprising: an addition circuit that adds and calculates the brightness of each of the fixed pixels.