JPH03131182A - Drive method for matrix type display device - Google Patents

Abstract

PURPOSE:To allow the method to deal with plural systems of television pictures by scanning a column driver for an effective scanning period only in the case of the wide display mode and scanning the column driver for the horizontal blanking period and the effective scanning period in the case of the 4:3 display mode. CONSTITUTION:The aspect ratio of the screen of a matrix type display device 1 is 16:9 and corresponds to the wide display mode for an HDTV or the like. In the case of the picture display in the 4:3 display mode, spaces 10, 11 are provided in an optional ratio to the left and right sides of a picture display section 9 and a video image of a prescribed gradation level is displayed to the spaces. Then in the case of the wide display mode, column drivers are scanned for the effective display period only for overscanning and the video signal is displayed on the matrix type display device. In the case of the 4:3 display mode, the column drivers are scanned for the horizontal blanking period and the effective scanning period and the signal of a prescribed level is displayed to the space.

Description

Detailed Description of the Invention 1. Field of Industrial Application 1. The present invention is applicable to conventional television images (aspect ratio 4:3) and wide aspect vision images (aspect ratio 16.9.5:3) such as HDTV. The present invention relates to a method for driving a matrix type display device that is designed to display images such as (e.g.).

[Conventional technology] Conventional televisions have a screen aspect ratio of 4:3.
It is assumed that On the other hand, next-generation televisions such as HDTV or HDTV conventionally require a horizontally long screen, for example, an aspect ratio of 16:9. Conventionally,
There is no doubt that there will be a demand for receivers that can display television images of these multiple systems. As display devices that meet such demands, Japanese Patent Application Laid-open Nos. 1-194574, 1-194575, and 1999
There is a video display device using a CRT (cathode ray tube) disclosed in No. 194,576. Regarding the structure and driving method of the matrix type display device, please refer to the document “
"Commercialized LCD Pocket Color TV" (Oguchi et al., Nikkei Electronics, September 10, 1984), page
, 233-P, 236. However, the current situation is that no effective proposal has yet been made regarding a receiver that uses a matrix type display device to display a plurality of television images with different aspect ratios.

[Problem to be Solved by the Invention 1] The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a conventional method (aspect ratio 4:3) to a horizontally long (for example, 16:9 aspect ratio) screen. An object of the present invention is to realize a driving method for a matrix type display device that can handle multiple formats of television images with different aspect ratios by providing an appropriate method for processing margins that occur when displaying television images.

[Means to solve the problem] A method for driving a matrix type display device according to the present invention is as follows.

(1) multiple column lines driven by column drivers;
In a method for driving a matrix type display device that displays images with a plurality of different aspect ratios, comprising a plurality of row lines driven by a row driver and picture elements formed at the intersections of the column lines and the row lines. , scans the column driver only during the valid scan period when in wide display mode;
In the 4:3 display mode, the column driver is scanned during a horizontal blanking period and an effective scanning period, and a signal of a predetermined gradation level is written in the margin portion during the horizontal blanking period.

(2) In the 4:3 display mode, the time ratio between the pulse width of the batting selection pulse from the driver and the video display period is approximately 4:3.

〔Example〕

Conventional television signals (NTSC, PAL, etc.) are based on the premise that images are displayed on a display with an aspect ratio of 4:3. On the other hand, the video signals of next-generation televisions such as HDTV (high-definition television) and
9) is designed to be displayed on a display. Hereinafter, the conventional mode for displaying images with an aspect ratio of 4:3 will be referred to as "4:3 display mode".
A mode in which an image is displayed at an aspect ratio that is wider than the normal screen (for example, 16:9) is called a "wide display mode."

FIG. 1 is a diagram for explaining the above two display modes using a matrix type display device.

In the figure, a matrix type display device 1 includes a plurality of column lines (4) connected to a column driver 2, a row driver 3
A plurality of row lines (5) are connected to the row lines, and picture elements (6, 7, 8) are formed at the intersections of the column lines and the row lines. Here, the column driver 2 includes a shift register 12, and the aspect ratio of the screen of the matrix display device 1 is 16.
:9 (horizontal) and is compatible with wide display modes such as HDTV. When displaying an image on the matrix type display device 1 in 4:3 display mode, margin areas 10 and 11 are set at an arbitrary ratio on the left and right sides of the image display section 9. , solid image).

FIG. 2 is a diagram for explaining a driving method in wide display mode. In the figure, ■1, SPl, and CKI are signals supplied to the column driver 2, and are a video signal (Vl) and a scan start signal (SPI) of the shift register 12, respectively.
), is the scanning clock (CKI) of the shift register 12, and LIOlLll and L12 respectively represent row line selection pulses supplied to the row lines from the row driver-3; for example, LIO is the scan clock (CKI) of the shift register 12; , Lll is the N+1st row line, L, 12 is the row line selection pulse for driving the N+2nd row line, 0 In the figure, Vl is the HDTV video signal, Pl is the horizontal blanking period, P2 represents an effective scanning period (a period during which a display signal exists).Actually, in order to perform a single bar scan, a video signal of period P3 of effective display period P2 is displayed on a matrix display device.

The display period P3 is determined by a scan start signal SP1 and a scan clock CKI supplied to the shift register 12 included in the column driver 2. If we focus on the row line of a certain book, and if there are a total of M picture elements on this row line, then the first picture element has time TI, the second picture element has time T2, The third pixel receives a video signal at time T3, ... the Mth pixel receives a video signal at time TM, and one or more operations are repeated every time all row lines are selected.
The pulse width of the row line selection pulse, that is, the row line selection period P4 includes the display period P3, and the adjacent row line selection pulse LlO1Ll
The selection periods of L1 and L12 do not overlap.

By doing the above, a normal horizontally long (for example, aspect ratio 16:9) image can be obtained in the wide display mode.

FIG. 3 is a diagram for explaining a driving method in 4:3 display mode. In the figure, 2 is a conventional television video signal. V3, SF3, and CK2 are signals supplied to the column driver-2, and each is a video signal (V3
), a scan start signal (SF3) for the shift register 12, a scan clock (CK2) for the shift register 12, and L20, L21 . L22 each represents a row line selection pulse supplied from the row driver 3 to the row line; for example, L20 drives the Nth row line, L21 drives the N+11th row line, and L22 drives the N+2nd row line. In Figure 1, the period P included in the video signal v2 is the row line selection pulse for
5 represents a horizontal blanking period, and P6 represents an effective scanning period (a period in which a display signal exists).Actually, the video signal of a predetermined period P7 included in the effective scanning period P6 is displayed on the matrix type display device. What is different from the case of the wide display mode described above is that a signal representing a predetermined gradation level A is transmitted before and after the video signal period P7 during a predetermined all-white period P8,
P9 is inserted to form a video signal V3, and the column driver
(2) is the point where this V3 is supplied. Therefore 4:3
The total display period PIO in the display mode consists of the video display period P7 and periods P8 and P9 for displaying the predetermined gradation level signal in the margin area. Note that the gradation level of the blank area may be B, which is different from A, during the display period P.
IO is determined by scan start signal SP2 and scan clock CK2. If we focus on the row line of a certain book, and if there are a total of M picture elements on this row line, then the first picture element has time T21, the second picture element has time T22, i
Time of T2i for the th picture element, T2M for the Mth picture element.
The pulse width of the 0 row line selection pulse, that is, the row line selection period pH, includes the display period P10, and the operation of 0 or more in which the video signal 3 is taken in is repeated every time all row lines are selected. Row line selection pulse L20. L21. L22
The selected periods do not overlap. By doing the above, a normal image can be obtained in the 4:3 display mode.

By the way, the relational expression for the case of the NTSC signal holds true. (rNHK Color TV Textbook [Part 1]” (Japan Broadcasting Publishing Association) P, 9) (P5+P6) Xo, 83=P6
(1) Since conventional televisions usually perform overscanning of about 10%, the following equation holds true.

P7 side 0.9XP6 (2) (1
), (2), P7 (P5+P6) xo, 75 (3) Therefore, in the present invention, the pulse width pH of the row selection pulse is set to (P5+
P6).

At this time, the video display period P7 is approximately 75% of the pH.

[Effects of the Invention] By adopting the driving method of the present invention as described above, it is possible to combine video signals with a horizontally long screen such as HDTV, which is a next-generation television system, and a video signal with an aspect ratio of 4:3, which is a conventional system. A matrix type display device capable of receiving and displaying both video signals based on a screen is realized.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining a matrix type display device and an image display section and a margin section. FIG. 2 is a diagram for explaining the present invention in detail. FIG. 3 is a diagram for explaining the present invention in detail. Driving force in 3rd display mode Driving force in 3rd display mode

Claims (2)

[Claims] (1) multiple column lines driven by column drivers;
In a method for driving a matrix type display device that displays images with a plurality of different aspect ratios, comprising a plurality of row lines driven by a row driver and picture elements formed at the intersections of the column lines and the row lines. , scans the column driver only during the valid scan period when in wide display mode;
In a 4:3 display mode, the column driver scans during a horizontal blanking period and an effective scanning period, and a signal of a predetermined gradation level is written in a margin during the horizontal blanking period. A method of driving a display device. (2) In the 4:3 display mode, the matrix type display according to claim 1, characterized in that the time ratio between the pulse width of the row line selection pulse from the row driver and the video display period is approximately 4:3. How to drive the device.