JPH03163588A - Matrix type image display device - Google Patents

Abstract

PURPOSE:To display a whole image under the state that it is scrolled by optionally delaying a start pulse, which is supplied, with respect to the signal of a vertical scanning cycle in an image signal and supplying it. CONSTITUTION:A hold circuit 13 which supplies a picture element signal in the image signal which is an object to be displayed to a matrix display element in a prescribed distributing state and a scanning circuit 12 which generates the signal of a horizontal scanning cycle after the start pulse generated based on the signal of the vertical scanning cycle in the image signal which is the object to be displayed and the subsequent start pulse and which scans successive column electrodes in the matrix display element 14 are provided. Then, the start pulse which is supplied is optionally delayed with respect to the signal of the vertical scanning cycle in the image signal and supplied to the circuit 12. Thus, the whole image is displayed under the state that it is scrolled on a matrix type display device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a matrix type image display device. (Conventional technique #I) Cathode ray tubes have been commonly used as display devices for displaying images, including television receivers, but in recent years Matrix-type image display devices using matrix display elements using liquid crystals have also come into widespread use, and matrix-type image display devices are also being used to display images on television receivers and personal computers. Ta. FIG. 3 is a diagram showing a schematic configuration of a matrix type image display device using a matrix display element using a liquid crystal, and an example of the matrix type image display device using a matrix display element using a liquid crystal is shown in FIG. a hold circuit that supplies pixel signals in the image signal targeted for display to the matrix display element in a predetermined distribution manner as shown in FIG. {Signal VD shown in (a} of FIG. 2)
The start pulse generated based on ((.) in Figure 2)
The horizontal scanning period signal (signal DX) shown in
Signals Xo, Xi, X2 shown in FIG. 2(a)
) to scan successive row electrodes in the matrix display element. The operating state of the matrix type image display device using the matrix display element using liquid crystal shown in FIG. 3 is when the signal X2 is given to the gate bus from the scanning circuit, and All field effect transistors whose gates are connected to a given gate bus are rendered conductive, and each field effect transistor rendered conductive stores the signal supplied via each drain bus from the hold circuit. Supply to the capacitor. The signal stored in the signal storage capacitor holds the liquid crystal in an excited state until the next signal X2 is applied to the gate bus, making the field effect transistor conductive. (Problem to be Solved by the Invention) Since there is no unified standard for the display device of the personal computer described above, the display device of a certain model of personal computer has 640 pixels horizontally x 2 pixels vertically.
A display element that can display a screen of 00 pixels must be used, and for display devices for other types of personal computers, display elements that can display a screen of 640 pixels horizontally x 350 pixels vertically must be used. , and display devices for other types of personal computers must use display elements that can display a screen of 640 pixels horizontally x 480 pixels vertically. (see figure) must be adopted. By the way, in a display device using a cathode ray tube, a horizontal deflection operation and a vertical deflection operation for the electron beam are performed in accordance with the horizontal scanning standard and vertical scanning standard of the image signal to be displayed. For example, images can be displayed using discrete image signals on the time axis or continuous image signals on the time axis, so it has traditionally been possible to vary the horizontal deflection frequency and vertical deflection frequency over a wide frequency range. Cathode ray display devices are now in use, which use deflection circuits similar to those described above, so that they can be used commonly as display devices for many types of personal computers. However, when trying to use a matrix type image display device using a matrix display element as a display device for a personal computer, since the two-dimensional pixel arrangement in the matrix type display element varies in various ways, the following problems occur. Problems such as this may occur. That is, for example, when trying to use a matrix type image display device as a display device of a personal computer to display a signal in the mode shown in VGA shown in FIG. 5 as an image, the above-mentioned VGA
It is not possible to obtain a matrix display element that can display a screen of 640 pixels horizontally x 480 pixels vertically, which is required to display the image of the signal in the mode indicated by GA, and the available matrix type display element is only 640 pixels horizontally. In the case of a matrix display element capable of displaying a screen of 400 vertical pixels, the image displayed by the matrix image display device configured using the matrix display element would be, for example, as shown in FIG. As shown in b), the bottom of the image is cut off. Note that the image illustrated in FIG. 4(a) is the entire image. Therefore, it was desirable to display all of the image information, not just a portion of the image, even in cases such as the one described above. (Means for Solving the Problems) The present invention provides a hold circuit that supplies pixel signals in an image signal to be displayed to a matrix display element in a predetermined distribution manner, and the above-described image signal to be displayed. In a matrix type image display device comprising a scanning circuit that generates a signal of a horizontal scanning period after a start pulse generated based on a signal of a vertical scanning period of the signal and scans successive row electrodes in a matrix display element. A matrix type image display device is provided, which is provided with means for generating a start pulse arbitrarily delayed with respect to a signal of a vertical scanning period in an image signal to be displayed. (Function) A hold circuit that supplies pixel signals in the image signal to be displayed to the matrix display element in a predetermined distribution manner, and a signal based on the vertical scanning period signal in the image signal to be displayed as described above. A start signal supplied to a scanning circuit in a matrix type image display device, which is equipped with a scanning circuit that generates a horizontal scanning cycle signal after a start pulse generated by a scanning circuit and scans successive row electrodes in a matrix display element. By applying pulses that are arbitrarily delayed with respect to the vertical scanning period of the image signal, the entire image can be displayed in a scrolled state on a matrix-type image display device. (Example) Hereinafter, specific contents of the matrix type image display device of the present invention will be explained in detail with reference to the attached drawings. FIG. 1 is a block diagram showing a schematic configuration of a matrix type image display device of the present invention, FIG. 2 is a waveform diagram for explaining the operation, and FIG.
This figure shows a schematic structure of a matrix type image display device using a matrix display element using liquid crystal, and FIG. 4 is an explanatory diagram of signal modes.

In Figure 1, 1 is a connector to which signals from a personal computer are supplied, 2 is an input terminal for television video signals, 3 is a synchronization separation circuit, 4 and 5 are changeover switches, and 6
is a switching control signal supply end; 7 is a monostable multivibrator; 8 is a capacitor; 9 is a variable resistor; 10 is a voltage supply terminal; 11 is a signal generation circuit; l2 is a scanning circuit; 13 is a hold circuit; and 14 is a matrix. This is a table display element.

The matrix display element l4 may have any configuration, for example, it may be a matrix display device using a matrix display element using liquid crystal, and the matrix display element l4 may have any structure. Sequential pixel signals in the image signal are given in the column direction in the matrix display element 14 by a pixel clock signal,
The scanning circuit 12 sequentially outputs signals xl,
This is a well-known structure in which an image corresponding to the image signal supplied to the hold circuit 14 is displayed on the matrix display element 14 by sequentially selecting one row in the matrix display element 14 for every x2... It is of a certain form (see Figure 3). The image signal among the output signals of the personal computer supplied to the connector 1 is supplied to the hold circuit 13 after signal processing by a signal processing system not shown in FIG. The television video signal (composite color television signal) supplied to the input terminal 2 is supplied to the sync separation circuit 3, and after being signal-processed by a signal processing system not shown in FIG. 1, it is sent to a hold circuit. It is supplied to 13. Further, the vertical scanning period signal VD among the output signals of the personal computer supplied to the connector 1 is supplied to the fixed contact P of the changeover switch 5, and is also supplied from the television video signal in the synchronization separation circuit 3. The separated vertical scanning period signal is sent to the fixed contact TI of the changeover switch 5.
is supplied to. Further, among the output signals of the personal computer supplied to the connector 1, the horizontal scanning period signal HD is supplied to the fixed contact P of the changeover switch 4, and is also supplied from the television video signal in the synchronization separation circuit 3. The separated horizontal scanning period signal is sent to the fixed contact T of the changeover switch 5.
1 is supplied. The movable contact a of the changeover switch 5 is connected to the trigger terminal of the monostable multivibrator 7, and the movable contact a of the changeover switch 4 is connected to the input terminal of the signal generation circuit 11. Since the movable contacts a and a of the two changeover switches 4 and 5 described above perform the switching operation in conjunction with the changeover control signal supplied to the changeover control signal supply terminal 6, the movable contact a of the changeover switch 5 Fixed contact T
When the vertical scanning period signal in the television video signal output from the synchronization separation circuit 3 by contacting the switch 1 is supplied to the trigger terminal of the monostable multivibrator 7 via the movable contact a, the changeover switch 4 The movable contact a contacts the fixed contact T1, and a horizontal scanning period signal in the television video signal output from the synchronization separation circuit 3 is supplied to the input terminal of the signal generation circuit 1l via the movable contact a. In addition, the movable contact a of the changeover switch 5 contacts the fixed contact P, and the vertical scanning period signal VD of the output signals of the personal computer is supplied to the connector l.
is supplied to the trigger terminal of the monostable multiviprator 7 via the movable contact a, the movable contact a of the changeover switch 4 comes into contact with the fixed contact P, and the terminal of the personal computer supplied to the connector 1 is Of the output signals, a signal HD with a horizontal scanning period is supplied to the input terminal of the signal generating circuit l1 via a movable contact a. As mentioned above, the monostable multivalve 7, in which the movable contact a of the changeover switch 5 is connected to the trigger terminal, is triggered by the vertical scanning period signal supplied thereto as a trigger signal.
An output pulse having a pulse width according to a time constant determined by a capacitor 8 and a variable resistor 9 is supplied to the signal generating circuit 1l. Note that a predetermined voltage is applied to the voltage supply terminal 10. The pulse width of the pulse output from the monostable multivibrator 7 described above is made variable by variably adjusting the variable resistor 9. Then, the trailing edge of the pulse output from the monostable multivibrator 7 triggered by the leading edge of the vertical scanning period signal supplied as a trigger signal to the monostable multivalve regulator 7 via the movable contact a of the changeover switch 5 The time position corresponds to the time point when the time position of the leading edge of the signal in the vertical scanning period is delayed by the pulse width of the pulse output from the monostable multivibrator 7. Therefore, when a new pulse whose leading edge is the time position of the trailing edge of the pulse output from the monostable multivibrator 7 is generated, the newly generated pulse is transferred to the movable contact a of the changeover switch 5. The vertical scanning period signal supplied as a trigger signal to the monostable multi-valve generator 7 via the monostable multi-valve generator 7 can be used as a time-delayed signal. A pulse in which the time position of the trailing edge of the output pulse from the . Further, the signal generation circuit 11 described above, to which a horizontal scanning period signal is supplied via the movable contact a of the changeover switch 4, generates horizontal scanning period clock signals Xi, X2, etc. to the scanning circuit 12. Supply to. 4g4 is a diagram for explaining the operation of the matrix type image display device of the present invention described above. (a) in Fig. 4 is, for example, the VG in Fig. 5.
This shows the state where the entire image is displayed at once on a matrix display element that can display a screen of 640 pixels horizontally x 480 pixels vertically, which is necessary to display the signal of the mode indicated by A as an image. , and (b) of the fourth @ is for example 640 horizontal pixels
The same image as shown in Fig. 4(a) is displayed on a 400-pixel matrix display element, that is, the lower part of the image is cut off in Fig. 4(b). The current state is shown. The matrix type image display device of the present invention is shown in FIG. 4(a).
The image shown in Figure 4(b) cannot be displayed because the number of pixels in the vertical direction of the screen in the matrix display element used for displaying the image is insufficient. As shown in , when the lower part of the image pattern can only be displayed at a time when it is cut off, the signal of the vertical scanning period of the image signal being displayed is arbitrarily delayed. By generating a state start pulse and supplying it to the scanning circuit 12, the state of the displayed image as shown in FIG.
The state of the displayed image as shown in c), (d) in Figure 4
The display image is scrolled in the vertical direction so that the entire display image can be displayed. This operation can be easily performed by variably adjusting the variable resistor 9 for varying the time constant of the monostable multivibrator 7. The delayed pulses VD, DX shown in the lower part of FIG. 2(b) are the same as the pulses VD, DX shown in the upper part of FIG. 2(b).
An example of pulses VD and DX in which DX is delayed by the monostable multivibrator 7 described above is shown.

(Effects of the Invention) As is clear from the above detailed explanation, the matrix type image display device of the present invention supplies pixel signals in the image signal to be displayed to the matrix display element in a predetermined distribution manner. and a hold circuit that generates a signal of a horizontal scanning period after the start pulse generated based on a signal of a vertical scanning period in the above-mentioned image copying signal to be displayed, and sequentially connects the row electrodes in the matrix display element. The start pulse to be supplied is arbitrarily delayed with respect to the signal of the vertical scanning period of the image signal, and is supplied to the scanning circuit in a matrix-type image display device, which is equipped with a scanning circuit for scanning a matrix-type image. Since the entire image can be displayed in a scrolled state on the display device, the problems of the conventional art described above can be satisfactorily solved according to the present invention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a matrix type image display device of the present invention, FIG. 2 is a waveform diagram for explaining the operation, and FIG.
The figure shows a matrix display using a liquid crystal.5Figure is an explanatory diagram of the signal mode. DESCRIPTION OF SYMBOLS 1... Connector to which personal computer signals are supplied, 2... Input terminal for television video signals, 3... Synchronization separation circuit, 4, 5... Changeover switch,
6... Switching control signal supply end 1, 7... Monostable multivibrator, 8... Capacitor, 9... Variable resistor, 10... Voltage supply terminal, 11... Signal generation circuit , 12... Scanning circuit, 13... Hold circuit, 1
4... Matrix display element, ゛Kaitono

Claims (1)

[Claims] a hold circuit that supplies pixel signals in the image signal to be displayed to the matrix display element in a predetermined distribution manner; In a matrix type image display device, which is equipped with a scanning circuit that generates a horizontal scanning cycle signal after a start pulse to scan successive row electrodes in a matrix display element, the vertical scanning period in the image signal to be displayed is A matrix type image display device provided with means for generating a start pulse arbitrarily delayed with respect to a signal of a scanning period.